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Sample records for primary fractionated stereotactic

  1. Fractionated Stereotactic Radiotherapy for Facial Nerve Schwannomas

    PubMed Central

    Shi, Wenyin; Jain, Varsha; Kim, Hyun; Champ, Colin; Jain, Gaurav; Farrell, Christopher; Andrews, David W.; Judy, Kevin; Liu, Haisong; Artz, Gregory; Werner-Wasik, Maria; Evans, James J.

    2015-01-01

    Purpose Data on the clinical course of irradiated facial nerve schwannomas (FNS) are lacking. We evaluated fractionated stereotactic radiotherapy (FSRT) for FNS. Methods Eight consecutive patients with FNS treated at our institution between 1998 and 2011 were included. Patients were treated with FSRT to a median dose of 50.4 Gy (range: 46.8–54 Gy) in 1.8 or 2.0 Gy fractions. We report the radiographic response, symptom control, and toxicity associated with FSRT for FNS. Results The median follow-up time was 43 months (range: 10–75 months). All patients presented with symptoms including pain, tinnitus, facial asymmetry, diplopia, and hearing loss. The median tumor volume was 1.57 cc. On the most recent follow-up imaging, five patients were noted to have stable tumor size; three patients had a net reduction in tumor volume. Additionally, six patients had improvement in clinical symptoms, one patient had stable clinical findings, and one patient had worsened House-Brackmann grade due to cystic degeneration. Conclusion FSRT treatment of FNS results in excellent control of growth and symptoms with a small rate of radiation toxicity. Given the importance of maintaining facial nerve function, FSRT could be considered as a primary management modality for enlarging or symptomatic FNS. PMID:26949592

  2. Stereotactic fractionated radiotherapy for the treatment of benign meningiomas

    SciTech Connect

    Candish, Charles; McKenzie, Michael . E-mail: mmckenzi@bccancer.bc.edu; Clark, Brenda G.; Ma, Roy; Lee, Richard; Vollans, Emily; Robar, James; Gete, Ermias; Martin, Monty

    2006-11-15

    Purpose: To assess the use of stereotactic fractionated radiotherapy (SRT) for the treatment of meningiomas. Methods and Materials: Between April 1999 and October 2004, 38 patients underwent SRT. Of 34 patients (36 tumors) assessed, the median age was 53 years. The indication was primary treatment in 26 cases (no histology) and postoperative in 10 cases. The most common sites were cavernous sinus (17), optic nerve (6), and cerebellopontine angle (5). The median gross target volume and planning target volume were 8.9 cm{sup 3} and 18.9 cm{sup 3}, respectively. Stereotactic treatment was delivered with 6-MV photons with static conformal fields (custom-made blocks, 9 patients, and micromultileaf collimator, 25 patients). Median number of fields was six. The median dose prescribed was 50 Gy (range, 45-50.4 Gy) in 28 fractions. The median homogeneity and conformality indices were 1.1 and 1.79, respectively. Results: Treatment was well tolerated. Median follow-up was 26 months with 100% progression-free survival. One patient developed an area of possible radionecrosis related to previous radiotherapy, and 2 men developed mild hypogonadism necessitating testosterone replacement. The vision of 5 of 6 patients with optic pathway meningiomas improved or remained static. Conclusions: Stereotactic fractionated radiotherapy for the treatment of meningiomas is practical, and with early follow-up, seems to be effective.

  3. Stereotactic Body Radiotherapy for Primary Hepatocellular Carcinoma

    SciTech Connect

    Andolino, David L.; Johnson, Cynthia S.; Maluccio, Mary; Kwo, Paul; Tector, A. Joseph; Zook, Jennifer; Johnstone, Peter A.S.; Cardenes, Higinia R.

    2011-11-15

    Purpose: To evaluate the safety and efficacy of stereotactic body radiotherapy (SBRT) for the treatment of primary hepatocellular carcinoma (HCC). Methods and Materials: From 2005 to 2009, 60 patients with liver-confined HCC were treated with SBRT at the Indiana University Simon Cancer Center: 36 Child-Turcotte-Pugh (CTP) Class A and 24 CTP Class B. The median number of fractions, dose per fraction, and total dose, was 3, 14 Gy, and 44 Gy, respectively, for those with CTP Class A cirrhosis and 5, 8 Gy, and 40 Gy, respectively, for those with CTP Class B. Treatment was delivered via 6 to 12 beams and in nearly all cases was prescribed to the 80% isodose line. The records of all patients were reviewed, and treatment response was scored according to Response Evaluation Criteria in Solid Tumors v1.1. Toxicity was graded according to the Common Terminology Criteria for Adverse Events v4.0. Local control (LC), time to progression (TTP), progression-free survival (PFS), and overall survival (OS) were calculated according to the method of Kaplan and Meier. Results: The median follow-up time was 27 months, and the median tumor diameter was 3.2 cm. The 2-year LC, PFS, and OS were 90%, 48%, and 67%, respectively, with median TTP of 47.8 months. Subsequently, 23 patients underwent transplant, with a median time to transplant of 7 months. There were no {>=}Grade 3 nonhematologic toxicities. Thirteen percent of patients experienced an increase in hematologic/hepatic dysfunction greater than 1 grade, and 20% experienced progression in CTP class within 3 months of treatment. Conclusions: SBRT is a safe, effective, noninvasive option for patients with HCC {<=}6 cm. As such, SBRT should be considered when bridging to transplant or as definitive therapy for those ineligible for transplant.

  4. Effectiveness of fractionated stereotactic radiotherapy for uveal melanoma

    SciTech Connect

    Muller, Karin; Nowak, Peter; Pan, Connie de; Marijnissen, Johannes P.; Paridaens, Dion A.; Levendag, Peter; Luyten, Gre P.M. . E-mail: g.p.m.luyten@erasmusmc.nl

    2005-09-01

    Purpose: To study the effectiveness and acute side effects of fractionated stereotactic radiation therapy (fSRT) for uveal melanoma. Methods and Materials: Between 1999 and 2003, 38 patients (21 male, 17 female) were included in a prospective, nonrandomized clinical trial (mean follow-up of 25 months). A total dose of 50 Gy was given in 5 consecutive days. A blinking light and a camera (to monitor the position of the diseased eye) were fixed to a noninvasive relocatable stereotactic frame. Primary end points were local control, best corrected visual acuity, and toxicity at 3, 6, 12, and 24 months, respectively. Results: After 3 months (38 patients), the local control was 100%; after 12 months (32 patients) and 24 months (15 patients), no recurrences were seen. The best corrected visual acuity declined from a mean of 0.21 at diagnosis to 0.06 2 years after therapy. The acute side effects after 3 months were as follows: conjunctival symptoms (10), loss of lashes or hair (6), visual symptoms (5), fatigue (5), dry eye (1), cataract (1), and pain (4). One eye was enucleated at 2 months after fSRT. Conclusions: Preliminary results demonstrate that fSRT is an effective and safe treatment modality for uveal melanoma with an excellent local control and mild acute side effects. The follow-up should be prolonged to study both long-term local control and late toxicity.

  5. Cushing's disease: a single centre's experience using the linear accelerator (LINAC) for stereotactic radiosurgery and fractionated stereotactic radiotherapy.

    PubMed

    Wilson, P J; Williams, J R; Smee, R I

    2014-01-01

    Cushing's disease is hypercortisolaemia secondary to an adrenocorticotrophic hormone secreting pituitary adenoma. Primary management is almost always surgical, with limited effective medical interventions available. Adjuvant therapy in the form of radiation is gaining popularity, with the bulk of the literature related to the Gamma Knife. We present the results from our own institution using the linear accelerator (LINAC) since 1990. Thirty-six patients who underwent stereotactic radiosurgery (SRS), one patient who underwent fractionated stereotactic radiotherapy (FSRT) and for the purposes of comparison, 13 patients who had undergone conventional radiotherapy prior to 1990, were included in the analysis. Serum cortisol levels improved in nine of 36 (25%) SRS patients and 24 hour urinary free cortisol levels improved in 13 of 36 patients (36.1%). Tumour volume control was excellent in the SRS group with deterioration in only one patient (3%). The patient who underwent FSRT had a highly aggressive tumour refractory to radiation.

  6. Nelson's syndrome: single centre experience using the linear accelerator (LINAC) for stereotactic radiosurgery and fractionated stereotactic radiotherapy.

    PubMed

    Wilson, Peter J; Williams, Janet R; Smee, Robert I

    2014-09-01

    Nelson's syndrome is a unique clinical phenomenon of growth of a pituitary adenoma following bilateral adrenalectomies for the control of Cushing's disease. Primary management is surgical, with limited effective medical therapies available. We report our own institution's series of this pathology managed with radiation: prior to 1990, 12 patients were managed with conventional radiotherapy, and between 1990 and 2007, five patients underwent stereotactic radiosurgery (SRS) and two patients fractionated stereotactic radiotherapy (FSRT), both using the linear accelerator (LINAC). Tumour control was equivocal, with two of the five SRS patients having a reduction in tumour volume, one patient remaining unchanged, and two patients having an increase in volume. In the FSRT group, one patient had a decrease in tumour volume whilst the other had an increase in volume. Treatment related morbidity was low. Nelson's syndrome is a challenging clinical scenario, with a highly variable response to radiation in our series.

  7. Fractionated Stereotactic Radiotherapy in Patients With Optic Nerve Sheath Meningioma

    SciTech Connect

    Paulsen, Frank; Doerr, Stefan; Wilhelm, Helmut; Becker, Gerd; Bamberg, Michael; Classen, Johannes

    2012-02-01

    Purpose: To evaluate the effectiveness of fractionated stereotactic radiotherapy (SFRT) in the treatment of optic nerve sheath meningioma (ONSM). Methods and Materials: Between 1993 and 2005, 109 patients (113 eyes) with primary (n = 37) or secondary (n = 76) ONSM were treated according to a prospective protocol with SFRT to a median dose of 54 Gy. All patients underwent radiographic, ophthalmologic, and endocrine analysis before and after SFRT. Radiographic response, visual control, and late side effects were endpoints of the analysis. Results: Median time to last clinical, radiographic, and ophthalmologic follow up was 30.2 months (n = 113), 42.7 months (n = 108), and 53.7 months (n = 91), respectively. Regression of the tumor was observed in 5 eyes and progression in 4 eyes, whereas 104 remained stable. Visual acuity improved in 12, deteriorated in 11, and remained stable in 68 eyes. Mean visual field defects reduced from 33.6% (n = 90) to 17.8% (n = 56) in ipsilateral and from 10% (n = 94) to 6.7% (n = 62) in contralateral eyes. Ocular motility improved in 23, remained stable in 65, and deteriorated in 3 eyes. Radiographic tumor control was 100% at 3 years and 98% at 5 years. Visual acuity was preserved in 94.8% after 3 years and in 90.9% after 5 years. Endocrine function was normal in 90.8% after 3 years and in 81.3% after 5 years. Conclusions: SFRT represents a highly effective treatment for ONSM. Interdisciplinary counseling of the patients is recommended. Because of the high rate of preservation of visual acuity we consider SFRT the standard approach for the treatment of ONSM. Prolonged observation is warranted to more accurately assess late visual impairment. Moderate de-escalation of the radiation dose might improve the preservation of visual acuity and pituitary gland function.

  8. Stereotactic Fractionated Radiotherapy in the Treatment of Juxtapapillary Choroidal Melanoma: The McGill University Experience

    SciTech Connect

    Al-Wassia, Rolina; Dal Pra, Alan; Shun, Kitty; Shaban, Ahmed; Corriveau, Christine; Edelstein, Chaim; Deschenes, Jean; Ruo, Russel; Patrocinio, Horacio; Cury, Fabio L.B.; DeBlois, Francois; Shenouda, George

    2011-11-15

    Purpose: To report our experience with linear accelerator-based stereotactic fractionated radiotherapy in the treatment of juxtapapillary choroidal melanoma. Methods and Materials: We performed a retrospective review of 50 consecutive patients diagnosed with juxtapapillary choroidal melanoma and treated with linear accelerator-based stereotactic fractionated radiotherapy between April 2003 and December 2009. Patients with small to medium sized lesions (Collaborative Ocular Melanoma Study classification) located within 2 mm of the optic disc were included. The prescribed radiation dose was 60 Gy in 10 fractions. The primary endpoints included local control, enucleation-free survival, and complication rates. Results: The median follow-up was 29 months (range, 1-77 months). There were 31 males and 29 females, with a median age of 69 years (range, 30-92 years). Eighty-four percent of the patients had medium sized lesions, and 16% of patients had small sized lesions. There were four cases of local progression (8%) and three enucleations (6%). Actuarial local control rates at 2 and 5 years were 93% and 86%, respectively. Actuarial enucleation-free survival rates at 2 and 5 years were 94% and 84%, respectively. Actuarial complication rates at 2 and 5 years were 33% and 88%, respectively, for radiation-induced retinopathy; 9.3% and 46.9%, respectively, for dry eye; 12% and 53%, respectively, for cataract; 30% and 90%, respectively, for visual loss [Snellen acuity (decimal equivalent), <0.1]; 11% and 54%, respectively, for optic neuropathy; and 18% and 38%, respectively, for neovascular glaucoma. Conclusions: Linear accelerator-based stereotactic fractionated radiotherapy using 60 Gy in 10 fractions is safe and has an acceptable toxicity profile. It has been shown to be an effective noninvasive treatment for juxtapapillary choroidal melanomas.

  9. Fractionated stereotactic radiosurgery for recurrent ependymoma in children

    PubMed Central

    Hoffman, Lindsey M.; Plimpton, S. Reed; Foreman, Nicholas K.; Stence, Nicholas V.; Hankinson, Todd C.; Handler, Michael H.; Hemenway, Molly S.; Vibhakar, Rajeev; Liu, Arthur K.

    2013-01-01

    Outcomes for children with relapsed ependymoma are poor. Re-irradiation is a potentially viable salvage option in these patients. Data were reviewed for 12 patients (median age 5.6 years) with relapsed ependymoma who received fractionated stereotactic radiosurgery (fSRS) following maximal surgical resection from 1995 to 2012. Four patients experienced a second recurrence, including 2 in-field and 2 distant failures. Median time to second recurrence (32 months) was significantly longer than time to first recurrence (24 months) (p = 0.008). Three-year local control was 89 %, and median event free survival from fSRS was 3.4 years. Radiation necrosis was observed in 6 patients, 3 who were symptomatic. In conclusion, fSRS offers durable response with a tolerable toxicity profile in children with recurrent EPN. PMID:24078173

  10. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

    SciTech Connect

    Rasmussen, Rune; Claesson, Magnus; Stangerup, Sven-Eric; Roed, Henrik; Christensen, Ib Jarle; Caye-Thomasen, Per; Juhler, Marianne

    2012-08-01

    Objective: To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hearing preservation was also investigated. Methods and Materials: Forty-two patients receiving FSRT between 1997 and 2008 with a minimum follow-up of 2 years were included. All patients received 54 Gy in 27-30 fractions during 5.5-6.0 weeks. Clinical and audiometry data were collected prospectively. From a 'wait-and-scan' group, 409 patients were selected as control subjects, matched by initial audiometric parameters. Radiation dose to the cochlea was measured using the original treatment plan and then related to changes in acoustic parameters. Results: Actuarial 2-, 4-, and 10-year tumor control rates were 100%, 91.5%, and 85.0%, respectively. Twenty-one patients had serviceable hearing before FSRT, 8 of whom (38%) retained serviceable hearing at 2 years after FSRT. No patients retained serviceable hearing after 10 years. At 2 years, hearing preservation rates in the control group were 1.8 times higher compared with the group receiving FSRT (P=.007). Radiation dose to the cochlea was significantly correlated to deterioration of the speech reception threshold (P=.03) but not to discrimination loss. Conclusion: FSRT accelerates the naturally occurring hearing loss in patients with vestibular schwannoma. Our findings, using fractionation of radiotherapy, parallel results using single-dose radiation. The radiation dose to the cochlea is correlated to hearing loss measured as the speech reception threshold.

  11. RT-01FRACTIONATED STEREOTACTIC RADIOTHERAPY FOR PITUITARY ADENOMA WITH NOVALIS

    PubMed Central

    Arakawa, Yoshiki; Mizowaki, Takashi; Ogura, Kengo; Sakanaka, Katsuyuki; Hojo, Masato; Hiraoka, Masahiro; Miyamoto, Susumu; Murata, Daiki

    2014-01-01

    BACKGROUND: Radiation therapy is an available treatment modality for pituitary adenoma. In particular, it is effective for the case unable to be removed with surgery or repeating recurrence. However, hypopituitarism and optic nerve injury associated with radiation therapy become a problem. Novalis® (Brain Lab) is an equipment of radiation to establish the detailed irradiation area, fractionated stereotactic radiotherapy (fSRT) and intensity-modulated radiation therapy (IMRT). Retrospectively, we review local control and morbidity following fSRT with Novalis in pituitary adenoma. PATIENTS AND METHODS: Between 2007 and 2012, 29 patients with pituitary adenoma (9 functioning, 20 non-functioning) received fSRT with Novalis in our institute. Total radiation dose was 50.4-54Gy (1.8 Gy per fraction) and prescribed to the gross target volume + 2 mm. The effectiveness of fSRT was evaluated by tumor volume and clinical symptoms on pre- fSRT, and every 1-year. RESULTS: The median follow-up time was 59.1 months (20 to 83 months). Tumor regrowth was observed in 2 cases. Progression free survival rate was 93%. New visual field deficit was observed in 1 case, and new pituitary dysfunction were not observed in all patients. CONCLUSION: fSRT with Novalis is safe and effective in the treatment for pituitary adenoma. Although follow-up time is short, any problematic complications were not observed. In the future, fSRT is expected to make for safe and effective treatment in pituitary adenoma impossible to cure surgically.

  12. Quantitative analysis of errors in fractionated stereotactic radiotherapy.

    PubMed

    Choi, D R; Kim, D Y; Ahn, Y C; Huh, S J; Yeo, I J; Nam, D H; Lee, J I; Park, K; Kim, J H

    2001-01-01

    Fractionated stereotactic radiotherapy (FSRT) offers a technique to minimize the absorbed dose to normal tissues; therefore, quality assurance is essential for these procedures. In this study, quality assurance for FSRT of 58 cases, between August 1995 and August 1997 are described, and the errors for each step and overall accuracy were estimated. Some of the important items for FSRT procedures are: accuracy in CT localization, transferred image distortion, laser alignment, isocentric accuracy of linear accelerator, head frame movement, portal verification, and various human errors. A geometric phantom, that has known coordinates was used to estimate the accuracy of CT localization. A treatment planning computer was used for checking the transferred image distortion. The mechanical isocenter standard (MIS), rectilinear phantom pointer: (RLPP), and laser target localizer frame (LTLF) were used for laser alignment and target coordinates setting. Head-frame stability check was performed by a depth confirmation helmet (DCH). A film test was done to check isocentric accuracy and portal verification. All measured data for the 58 patients were recorded and analyzed for each item. 4-MV x-rays from a linear accelerator, were used for FSRT, along with homemade circular cones with diameters from 20 to 70 mm (interval: 5 mm). The accuracy in CT localization was 1.2+/-0.5 mm. The isocentric accuracy of the linear accelerator, including laser alignment, was 0.5+/-0.2 mm. The reproducibility of the head frame was 1.1+/-0.6 mm. The overall accuracy was 1.7+/-0.7 mm, excluding human errors.

  13. Fractionated Stereotactic Gamma Knife Radiosurgery for Large Brain Metastases: A Retrospective, Single Center Study

    PubMed Central

    Park, Hye Ran; Lee, Jae Meen; Kim, Jin Wook; Chung, Hyun-Tai; Kim, Dong Gyu; Jung, Hee-Won

    2016-01-01

    Purpose Stereotactic radiosurgery (SRS) is widely used for brain metastases but has been relatively contraindicated for large lesions (>3 cm). In the present study, we analyzed the efficacy and toxicity of hypofractionated Gamma Knife radiosurgery to treat metastatic brain tumors for which surgical resection were not considered as the primary treatment option. Methods and Materials Thirty-six patients, forty cases were treated with Gamma Knife-based fractionated SRS for three to four consecutive days with the same Leksell frame on their heads. The mean gross tumor volume was 18.3 cm³, and the median dose was 8 Gy at 50% isodose line with 3 fractions for three consecutive days (range, 5 to 11 Gy and 2 to 4 fractions for 2 to 4 consecutive days). Survival rates and prognostic factors were analyzed. Results The overall survival rate at one and two years was 66.7 and 33.1%, respectively. The median survival time was 16.2 months, and the local control rate was 90%. RTOG toxicity grade 1 was observed in 3 (8.3%) patients, grade 2 in 1 (2.7%) patient and grade 3 in 1 (2.7%) patient respectively. Radiation necrosis was developed in 1 (2.7%) patient. KPS scores and control of primary disease resulted in significant differences in survival. Conclusions Our findings suggest that consecutive hypofractionated Gamma Knife SRS could be applied to large metastatic brain tumors with effective tumor control and low toxicity rates. PMID:27661613

  14. Stereotactic Body Radiotherapy for Primary Lung Cancer at a Dose of 50 Gy Total in Five Fractions to the Periphery of the Planning Target Volume Calculated Using a Superposition Algorithm

    SciTech Connect

    Takeda, Atsuya; Sanuki, Naoko; Kunieda, Etsuo Ohashi, Toshio; Oku, Yohei; Takeda, Toshiaki; Shigematsu, Naoyuki; Kubo, Atsushi

    2009-02-01

    Purpose: To retrospectively analyze the clinical outcomes of stereotactic body radiotherapy (SBRT) for patients with Stages 1A and 1B non-small-cell lung cancer. Methods and Materials: We reviewed the records of patients with non-small-cell lung cancer treated with curative intent between Dec 2001 and May 2007. All patients had histopathologically or cytologically confirmed disease, increased levels of tumor markers, and/or positive findings on fluorodeoxyglucose positron emission tomography. Staging studies identified their disease as Stage 1A or 1B. Performance status was 2 or less according to World Health Organization guidelines in all cases. The prescribed dose of 50 Gy total in five fractions, calculated by using a superposition algorithm, was defined for the periphery of the planning target volume. Results: One hundred twenty-one patients underwent SBRT during the study period, and 63 were eligible for this analysis. Thirty-eight patients had Stage 1A (T1N0M0) and 25 had Stage 1B (T2N0M0). Forty-nine patients were not appropriate candidates for surgery because of chronic pulmonary disease. Median follow-up of these 49 patients was 31 months (range, 10-72 months). The 3-year local control, disease-free, and overall survival rates in patients with Stages 1A and 1B were 93% and 96% (p = 0.86), 76% and 77% (p = 0.83), and 90% and 63% (p = 0.09), respectively. No acute toxicity was observed. Grade 2 or higher radiation pneumonitis was experienced by 3 patients, and 1 of them had fatal bacterial pneumonia. Conclusions: The SBRT at 50 Gy total in five fractions to the periphery of the planning target volume calculated by using a superposition algorithm is feasible. High local control rates were achieved for both T2 and T1 tumors.

  15. Long-Term Outcomes of Vestibular Schwannomas Treated With Fractionated Stereotactic Radiotherapy: An Institutional Experience

    SciTech Connect

    Kapoor, Sumit; Batra, Sachin; Carson, Kathryn; Shuck, John; Kharkar, Siddharth; Gandhi, Rahul; Jackson, Juan; Wemmer, Jan; Terezakis, Stephanie; Shokek, Ori; Kleinberg, Lawrence; Rigamonti, Daniele

    2011-11-01

    Purpose: We assessed clinical outcome and long-term tumor control after fractionated stereotactic radiotherapy (FSRT) for unilateral schwannoma. Methods and Materials: Between 1995 and 2007, 496 patients were treated with fractionated stereotactic radiotherapy at Johns Hopkins Hospital (Baltimore, MD); 385 patients had radiologic follow-up that met the inclusion criteria. The primary endpoint was treatment failure. Secondary endpoints were radiologic progression and clinical outcome. Logistic regression analysis assessed the association of age, race, tumor side, sex, and pretreatment symptoms. Results: In 11 patients (3%) treatment failed, and they required salvage (microsurgical) treatment. Radiologic progression was observed in 116 patients (30.0%), including 35 patients (9%) in whom the treatment volume more than doubled during the follow-up period, although none required surgical resection. Tumors with baseline volumes of less than 1 cm{sup 3} were 18.02 times more likely to progress than those with tumor volumes of 1 cm{sup 3} or greater (odds ratio, 18.02; 95% confidence interval, 4.25-76.32). Treatment-induced neurologic morbidity included 8 patients (1.6%) with new facial weakness, 12 patients (2.8%) with new trigeminal paresthesias, 4 patients (0.9%) with hydrocephalus (1 communicating and 3 obstructive), and 2 patients (0.5%) with possibly radiation-induced neoplasia. Conclusions: Although the rate of treatment failure is low (3%), careful follow-up shows that radiologic progression occurs frequently. When reporting outcome, the 'no salvage surgery needed' and 'no additional treatment needed' criteria for treatment success need to be complemented by the radiologic data.

  16. Intra-fraction dose delivery timing during stereotactic radiotherapy can influence the radiobiological effect

    SciTech Connect

    Murphy, Martin J.; Lin, Peck-Sun; Ozhasoglu, Cihat

    2007-02-15

    The sequence of incremental dose delivery during a radiotherapy fraction can potentially influence the radiobiological effect. This would be most noticeable during the long fractions characteristic of hypo-fractionated stereotactic radiotherapy and radiosurgery. We demonstrate here the spatio-temporal variation of dose delivery by the CyberKnife to a lung tumor and propose strategies to reduce and/or correct for any resultant dose-time cytotoxic effects.

  17. Fractionated Stereotactic Radiotherapy in the Treatment of Vestibular Schwannoma (Acoustic Neuroma): Predicting the Risk of Hydrocephalus;Vestibular schwannoma; Hydrocephalus; Fractionated; Stereotactic radiotherapy

    SciTech Connect

    Powell, Ceri; Micallef, Caroline; Gonsalves, Adam; Wharram, Bev; Ashley, Sue; Brada, Michael

    2011-07-15

    Purpose: To determine the incidence and predictive factors for the development of hydrocephalus in patients with acoustic neuromas (AN) treated with fractionated stereotactic radiotherapy. Patients and Methods: Seventy-two patients with AN were treated with fractionated stereotactic radiotherapy between 1998 and 2007 (45-50 Gy in 25-30 fractions over 5 to 6 weeks). The pretreatment MRI scan was assessed for tumor characteristics and anatomic distortion independently of subsequent outcome and correlated with the risk of hydrocephalus. Results: At a median follow-up of 49 months (range, 1-120 months), 5-year event-free survival was 95%. Eight patients (11%) developed hydrocephalus within 19 months of radiotherapy, which was successfully treated. On univariate analysis, pretreatment factors predictive of hydrocephalus were maximum diameter (p = 0.005), proximity to midline (p = 0.009), displacement of the fourth ventricle (p = 0.02), partial effacement of the fourth ventricle (p < 0.001), contact with the medulla (p = 0.005), and more brainstem structures (p = 0.004). On multivariate analysis, after adjusting for fourth ventricular effacement, no other variables remained independently associated with hydrocephalus formation. Conclusions: Fractionated stereotactic radiotherapy results in excellent tumor control of AN, albeit with a risk of developing hydrocephalus. Patients at high risk, identified as those with larger tumors with partial effacement of the fourth ventricle before treatment, should be monitored more closely during follow-up. It would also be preferable to offer treatment to patients with progressive AN while the risk of hydrocephalus is low, before the development of marked distortion of fourth ventricle before tumor diameter significantly exceeds 2 cm.

  18. Early manifestation of communicating hydrocephalus after fractionated stereotactic radiotherapy for aggressive giant atypical prolactinoma.

    PubMed

    Ohtakara, Kazuhiro; Ohe, Naoyuki; Iwama, Toru; Hoshi, Hiroaki

    2014-05-01

    Aggressive giant invasive pituitary adenomas refractory to standard surgical or medical treatment remain a genuine challenge. In addition, communicating hydrocephalus (CH) attributed to malabsorption of cerebrospinal fluid (CSF) developing after radiotherapy for pituitary adenomas has not been previously reported. Herein, we describe the case of a 48-year-old male presenting with a giant atypical prolactinoma refractory to previous therapies, including pharmacotherapy and repetitive surgery. He underwent image-guided fractionated stereotactic radiotherapy in 28 fractions, resulting in early manifestation of CH associated with undisputed, both radiological and hormonal response. He recovered well after a shunt placement, with otherwise favorable consequences such as sustained tumor regression, decreasing prolactin level, and retained visual function for a 22-month follow-up. Fractionated stereotactic radiotherapy would provide a viable treatment alternative for these refractory cases, while caution should be exercised regarding the possibility of iatrogenic CH.

  19. 3D quantitative assessment of response to fractionated stereotactic radiotherapy and single-session stereotactic radiosurgery of vestibular schwannoma

    PubMed Central

    Schneider, T.; Chapiro, J.; Lin, M.; Geschwind, J. F.; Kleinberg, L.; Rigamonti, D.; Jusué-Torres, I.; Marciscano, A. E.; Yousem, D. M.

    2015-01-01

    Objectives To determine clinical outcome of patients with vestibular schwannoma (VS) after treatment with fractionated stereotactic radiotherapy (FSRT) and single-session stereotactic radiosurgery (SRS) by using 3D quantitative response assessment on MRI. Materials This retrospective analysis included 162 patients who underwent radiation therapy for sporadic VS. Measurements on T1-weighted contrast-enhanced MRI (in 2-year post-therapy intervals: 0–2, 2–4, 4–6, 6–8, 8–10, and 10–12 years) were taken for total tumour volume (TTV) and enhancing tumour volume (ETV) based on a semi-automated technique. Patients were considered non-responders (NRs) if they required subsequent microsurgical resection or developed radiological progression and tumour-related symptoms. Results Median follow-up was 4.1 years (range: 0.4–12.0). TTV and ETV decreased for both the FSRT and SRS groups. However, only the FSRT group achieved significant tumour shrinkage (p < 0.015 for TTV, p < 0.005 for ETV over time). The 11 NRs showed proportionally greater TTV (median TTV pre-treatment: 0.61 cm3, 8–10 years after: 1.77 cm3) and ETV despite radiation therapy compared to responders (median TTV pre-treatment: 1.06 cm3; 10–12 years after: 0.81 cm3; p = 0.001). Conclusion 3D quantification of VS showed a significant decrease in TTV and ETV on FSRT-treated patients only. NRs had significantly greater TTV and ETV over time. PMID:26139318

  20. Robotic Image-Guided Stereotactic Radiotherapy, for Isolated Recurrent Primary, Lymph Node or Metastatic Prostate Cancer

    SciTech Connect

    Jereczek-Fossa, Barbara Alicja; Beltramo, Giancarlo; Fariselli, Laura; Fodor, Cristiana; Santoro, Luigi; Vavassori, Andrea; Zerini, Dario; Gherardi, Federica; Ascione, Carmen; Bossi-Zanetti, Isa; Mauro, Roberta; Bregantin, Achille; Bianchi, Livia Corinna; De Cobelli, Ottavio; Orecchia, Roberto

    2012-02-01

    Purpose: To evaluate the outcome of robotic CyberKnife (Accuray, Sunnyvale, CA)-based stereotactic radiotherapy (CBK-SRT) for isolated recurrent primary, lymph node, or metastatic prostate cancer. Methods and Materials: Between May 2007 and December 2009, 34 consecutive patients/38 lesions were treated (15 patients reirradiated for local recurrence [P], 4 patients reirradiated for anastomosis recurrence [A], 16 patients treated for single lymph node recurrence [LN], and 3 patients treated for single metastasis [M]). In all but 4 patients, [{sup 11}C]choline positron emission tomography/computed tomography was performed. CBK-SRT consisted of reirradiation and first radiotherapy in 27 and 11 lesions, respectively. The median CBK-SRT dose was 30 Gy in 4.5 fractions (P, 30 Gy in 5 fractions; A, 30 Gy in 5 fractions; LN, 33 Gy in 3 fractions; and M, 36 Gy in 3 fractions). In 18 patients (21 lesions) androgen deprivation was added to CBK-SRT (median duration, 16.6 months). Results: The median follow-up was 16.9 months. Acute toxicity included urinary events (3 Grade 1, 2 Grade 2, and 2 Grade 3 events) and rectal events (1 Grade 1 event). Late toxicity included urinary events (3 Grade 1, 2 Grade 2, and 2 Grade 3 events) and rectal events (1 Grade 1 event and 1 Grade 2 event). Biochemical response was observed in 32 of 38 evaluable lesions. Prostate-specific antigen stabilization was seen for 4 lesions, and in 2 cases prostate-specific antigen progression was reported. The 30-month progression-free survival rate was 42.6%. Disease progression was observed for 14 lesions (5, 2, 5, and 2 in Groups P, A, LN, and M respectively). In only 3 cases, in-field progression was seen. At the time of analysis (May 2010), 19 patients are alive with no evidence of disease and 15 are alive with disease. Conclusions: CyberKnife-based stereotactic radiotherapy is a feasible approach for isolated recurrent primary, lymph node, or metastatic prostate cancer, offering excellent in-field tumor

  1. Visual Outcome in Meningiomas Around Anterior Visual Pathways Treated With Linear Accelerator Fractionated Stereotactic Radiotherapy

    SciTech Connect

    Stiebel-Kalish, Hadas; Reich, Ehud; Gal, Lior; Rappaport, Zvi Harry; Nissim, Ouzi; Pfeffer, Raphael; Spiegelmann, Roberto

    2012-02-01

    Purpose: Meningiomas threatening the anterior visual pathways (AVPs) and not amenable for surgery are currently treated with multisession stereotactic radiotherapy. Stereotactic radiotherapy is available with a number of devices. The most ubiquitous include the gamma knife, CyberKnife, tomotherapy, and isocentric linear accelerator systems. The purpose of our study was to describe a case series of AVP meningiomas treated with linear accelerator fractionated stereotactic radiotherapy (FSRT) using the multiple, noncoplanar, dynamic conformal rotation paradigm and to compare the success and complication rates with those reported for other techniques. Patients and Methods: We included all patients with AVP meningiomas followed up at our neuro-ophthalmology unit for a minimum of 12 months after FSRT. We compared the details of the neuro-ophthalmologic examinations and tumor size before and after FSRT and at the end of follow-up. Results: Of 87 patients with AVP meningiomas, 17 had been referred for FSRT. Of the 17 patients, 16 completed >12 months of follow-up (mean 39). Of the 16 patients, 11 had undergone surgery before FSRT and 5 had undergone FSRT as first-line management. Tumor control was achieved in 14 of the 16 patients, with three meningiomas shrinking in size after RT. Two meningiomas progressed, one in an area that was outside the radiation field. The visual function had improved in 6 or stabilized in 8 of the 16 patients (88%) and worsened in 2 (12%). Conclusions: Linear accelerator fractionated RT using the multiple noncoplanar dynamic rotation conformal paradigm can be offered to patients with meningiomas that threaten the anterior visual pathways as an adjunct to surgery or as first-line treatment, with results comparable to those reported for other stereotactic RT techniques.

  2. Local control rates with five-fraction stereotactic body radiotherapy for oligometastatic cancer to the lung

    PubMed Central

    Chen, Yuhchyau; Hare, Mary Z.; Usuki, Kenneth Y.; Zhang, Hong; Lundquist, Thomas; Joyce, Neil; Schell, Michael C.; Milano, Michael T.

    2014-01-01

    Objective To report our institutional experience with five fractions of daily 8-12 Gy stereotactic body radiotherapy (SBRT) for the treatment of oligometastatic cancer to the lung. Methods Thirty-four consecutive patients with oligometastatic cancers to the lung were treated with image-guided SBRT between 2008 and 2011. Patient age ranged from 38 to 81 years. There were 17 males and 17 females. Lung metastases were from the following primary cancer types: colon cancer (n=13 patients), head and neck cancer (n=6), breast cancer (n=4), melanoma (n=4), sarcoma (n=4) and renal cell carcinoma (n=3). The median prescription dose was 50 Gy in five fractions (range, 40-60 Gy) to the isocenter, with the 80% isodose line encompassing the planning target volume (PTV) [defined as gross tumor volume (GTV) + 7-11 mm volumetric expansion]. The follow-up interval ranged from 2.4-54 months, with a median of 16.7 months. Results The 1-, 2-, and 3-year patient local control (LC) rates for all patients were 93%, 88%, and 80% respectively. The 1-, 2-, and 3-year overall survival (OS) rates were 62%, 44%, and 23% respectively. The 1- and 2-year patient LC rates were 95% and 88% for tumor size 1-2 cm (n=25), and 86% for tumor size 2-3 cm (n=7). The majority (n=4) of local failures occurred within 12 months. No patient experienced local failure after 12 months except for one patient with colon cancer whose tumors progressed locally at 26 months. All five patients with local recurrences had colorectal cancer. Statistical analyses showed that age, gender, previous chemotherapy, previous surgery or radiation had no significant effect on LC rates. No patient was reported to have any symptomatic pneumonitis at any time point. Conclusions SBRT for oligometastatic disease to the lung using 8-12 Gy daily fractions over five treatments resulted in excellent 1- and 2-year LC rates. Most local failures occurred within the first 12 months, with five local failures associated with colorectal cancer

  3. Five-Year Outcomes of High-Dose Single-Fraction Spinal Stereotactic Radiosurgery

    SciTech Connect

    Moussazadeh, Nelson; Lis, Eric; Katsoulakis, Evangelia; Kahn, Sweena; Svoboda, Marek; DiStefano, Natalie M.; McLaughlin, Lily; Bilsky, Mark H.; Yamada, Yoshiya; Laufer, Ilya

    2015-10-01

    Purpose: To characterize local tumor control and toxicity risk in very long-term survivors (>5 years) after high-dose spinal image guided, intensity modulated radiation therapy delivered as single-dose stereotactic radiosurgery (SRS). Previously published spinal SRS outcome analyses have included a heterogeneous population of cancer patients, mostly with short survival. This is the first study reporting the long-term tumor control and toxicity profiles after high-dose single-fraction spinal SRS. Methods and Materials: The study population included all patients treated from June 2004 to July 2009 with single-fraction spinal SRS (dose 24 Gy) who had survived at least 5 years after treatment. The endpoints examined included disease progression, surgical or radiation retreatment, in-field fracture development, and radiation-associated toxicity, scored using the Radiation Therapy Oncology Group radiation morbidity scoring criteria and the Common Terminology Criteria for Adverse Events, version 4.0. Local control and fracture development were assessed using Kaplan-Meier analysis. Results: Of 278 patients, 31 (11.1%), with 36 segments treated for spinal tumors, survived at least 5 years after treatment and were followed up radiographically and clinically for a median of 6.1 years (maximum 102 months). The histopathologic findings for the 5-year survivors included radiation-resistant metastases in 58%, radiation-sensitive metastases in 22%, and primary bone tumors in 19%. In this selected cohort, 3 treatment failures occurred at a median of 48.6 months, including 2 recurrences in the radiation field and 1 patient with demonstrated progression at the treatment margins. Ten lesions (27.8%) were associated with acute grade 1 cutaneous or gastrointestinal toxicity. Delayed toxicity ≥3 months after treatment included 8 cases (22.2%) of mild neuropathy, 2 (5.6%) of gastrointestinal discomfort, 8 (22.2%) of dermatitides, and 3 (8.3%) of myalgias/myositis. Thirteen

  4. Extracranial stereotactic body radiotherapy. Review of main SBRT features and indications in primary tumors

    PubMed Central

    Rubio, Carmen; Morera, Rosa; Hernando, Ovidio; Leroy, Thomas.; Lartigau, S. Eric

    2013-01-01

    Aim Review of main SBRT features and indications in primary tumors. Background Stereotactic body radiotherapy has been developed in the last few years. SBRT allows the hypofractionated treatment of extra cranial tumors, using either a single or limited number of dose fractions, and resulting in the delivery of a high biological effective dose with low toxicity. Material and methods SBRT requires a high level of accuracy for all phases of the treatment process: effective patient immobilization, precise target localization, highly conformed dosimetry and image guided systems for treatment verification. The implementation of SBRT in routine requires a careful considering of organ motion. Gating and tracking are effective ways to do so, and less invasive technologies “fiducials free” have been developed. Due to the hypofractionated scheme, the physician must pay attention to new dosimetric constraints in organ at risk and new radiobiological models are needed to assess the optimal fractionation and dose schemes. Results Currently, SBRT is safe and effective to treat primary tumors, which are otherwise untreatable with conventional radiotherapy or surgery. SBRT has quickly developed because of its excellent results in terms of tolerance and its high locoregional control rates. SBRT indications in primary tumors, such as lung primary tumors, have become a standard of care for inoperable patients. SBRT seems to be effective in many others indications in curative or palliative intent such as liver primary tumors, and novel indications and strategies are currently emerging in prostate cancer, head and neck tumor recurrences or pelvis reirradiations. Conclusion Currently, SBRT is mainly used when there is no other therapeutic alternative for the patient. This is due to the lack of randomized trials in these settings. However, the results shown in retrospective studies let us hope to impose SBRT as a new standard of care for many patients in the next few years. PMID

  5. Effect of Fractionation in Stereotactic Body Radiation Therapy Using the Linear Quadratic Model

    SciTech Connect

    Yang, Jun; Lamond, John; Fowler, Jack; Lanciano, Rachelle; Feng, Jing; Brady, Luther

    2013-05-01

    Purpose: To examine the fractionation effect of stereotactic body radiation therapy with a heterogeneous dose distribution. Methods: Derived from the linear quadratic formula with measurements from a hypothetical 2-cm radiosurgical tumor, the threshold percentage was defined as (α/β{sub tissue}/α/β{sub tumor}), the balance α/β ratio was defined as (prescription dose/tissue tolerance*α/β{sub tumor}), and the balance dose was defined as (tissue tolerance/threshold percentage). Results: With increasing fractions and equivalent peripheral dose to the target, the biological equivalent dose of “hot spots” in a target decreases. The relative biological equivalent doses of serial organs decrease only when the relative percentage of its dose to the prescription dose is above the threshold percentage. The volume of parallel organs at risk decreases only when the tumor's α/β ratio is above the balance α/β ratio and the prescription dose is lower than balance dose. Conclusions: The potential benefits of fractionation in stereotactic body radiation therapy depend on the complex interplay between the total dose, α/β ratios, and dose differences between the target and the surrounding normal tissues.

  6. Stereotactic ablative body radiotherapy (SABR) for primary and secondary lung tumours

    PubMed Central

    Gaya, Andrew

    2012-01-01

    Abstract Stereotactic ablative body radiotherapy (SABR) represents a technological breakthrough in radiotherapy technique, with proven benefits to patients in terms of improved tumour control and overall survival. The key components of SABR are described. The current evidence base for SABR for the treatment of primary and secondary lung tumours is appraised, and key ongoing trials are identified. PMID:23023165

  7. Fractionated stereotactic radiosurgery using the Novalis system for the management of pituitary adenomas close to the optic apparatus.

    PubMed

    Liao, Huang-I; Wang, Chun-Chieh; Wei, Kuo-Cheng; Chang, Cheng-Nen; Hsu, Yung-Hsin; Lee, Shih-Tseng; Huang, Yin-Cheng; Chen, Hsien-Chih; Hsu, Peng-Wei

    2014-01-01

    Radiosurgery has been proven to be an effective treatment for residual or recurrent pituitary adenomas after surgery. However, it causes severe complications when the optic apparatus is irradiated over the tolerance dose. In this study, we analyzed the feasibility of fractionated stereotactic radiosurgery to treat pituitary tumors close to the optic apparatus. Thirty-four patients from June 2006 to June 2011 with recurrent or residual pituitary adenomas close to (<3 mm) the optic apparatus were treated with fractionated stereotactic radiosurgery. Three fractions with a total dose of 2100 cGy were applied to the tumors. Imaging, examination of vision, and estimation of hormone level were regularly performed before and after radiosurgery. The mean tumor volume before fractioned stereotactic radiosurgery was 5.06±3.08 cm3 (range: 0.82-12.69 cm3). After a mean follow up of 36.8±15.7 months (range: 16-72 months), tumor size was reduced in seven (20.6%) patients and remained the same in the other 27 (79.4%) patients. Vision was improved in one patient and remained stable in the rest. Only one patient developed transient post-treatment diplopia. This study suggests that fractionated stereotactic radiosurgery is safe for treating pituitary adenomas close to the optic apparatus. Studies with more patients and longer follow-up are required to draw definite conclusions.

  8. Fractionated Stereotactic Radiotherapy as Reirradiation for Locally Recurrent Head and Neck Cancer

    SciTech Connect

    Roh, Kwang-Won; Jang, Ji-Sun; Kim, Min-Sik; Sun, Dong-Il; Kim, Bum-Soo; Jung, So-Lyoung; Kang, Jin-Hyoung; Yoo, Eun-Jung; Yoon, Sei-Chul; Jang, Hong-Seok; Chung, Su-Mi; Kim, Yeon-Sil

    2009-08-01

    Purpose: We report early preliminary experience with CyberKnife radiosurgery (RS) as salvage treatment for locally recurrent head and neck cancer (HNC). Methods and Materials: Between March 2004 and August 2006, 36 patients (44 sites) were treated with CyberKnife RS as reirradiation for locally recurrent HNC. Treatment sites were as follows: nasopharynx (8), maxillary sinus (8), neck lymph nodes (8), skull base (7), nasal cavity (4), retropharyngeal lymph nodes (3), orbit (2), and others (4). Total doses administered were 18-40 Gy (median, 30 Gy) in 3 to 5 fractions to the 65%-85% isodose line for 3-5 consecutive days. Previous external radiation dose ranged from 39.6 to 134.4 Gy (median, 70.2 Gy). Gross tumor volume ranged from 0.2 to 114.9 cm{sup 3} (median, 22.6 cm{sup 3}). Median follow-up was 17.3 months. Results: Thirty-five of 44 sites were evaluated for response. Fifteen (42.9%) sites achieved complete response, 13 sites (37.1%) achieved a partial response, 3 (8.6%) sites maintained stable disease, and 4 sites (11.4%) showed tumor progression. Grade III acute complications were noted in 13 patients. Late complications were observed in three patients (1 bone necrosis, 2 soft tissue necrosis) during follow-up. Conclusion: These preliminary results suggest that fractionated stereotactic radiosurgery is an effective treatment modality as a salvage treatment with good short-term local control. The early overall response rate is encouraging. However, more experience and a longer follow-up are necessary to determine the role of fractionated stereotactic radiosurgery as a salvage treatment of locally recurrent HNC and to define long-term complications.

  9. Single Fraction Versus Fractionated Linac-Based Stereotactic Radiotherapy for Vestibular Schwannoma: A Single-Institution Experience

    SciTech Connect

    Collen, Christine; Ampe, Ben; Gevaert, Thierry; Moens, Maarten; Linthout, Nadine; De Ridder, Mark; Verellen, Dirk; D'Haens, Jean; Storme, Guy

    2011-11-15

    Purpose: To evaluate and compare outcomes for patients with vestibular schwannoma (VS) treated in a single institution with linac-based stereotactic radiosurgery (SRS) or by fractionated stereotactic radiotherapy (SRT). Methods and Materials: One hundred and nineteen patients (SRS = 78, SRT = 41) were treated. For both SRS and SRT, beam shaping is performed by a mini-multileaf collimator. For SRS, a median single dose of 12.5 Gy (range, 11-14 Gy), prescribed to the 80% isodose line encompassing the target, was applied. Of the 42 SRT treatments, 32 treatments consisted of 10 fractions of 3-4 Gy, and 10 patients received 25 sessions of 2 Gy, prescribed to the 100% with the 95% isodose line encompassing the planning target volume. Mean largest tumor diameter was 16.6 mm in the SRS and 24.6 mm in the SRT group. Local tumor control, cranial nerve toxicity, and preservation of useful hearing were recorded. Any new treatment-induced cranial nerve neuropathy was scored as a complication. Results: Median follow-up was 62 months (range, 6-136 months), 5 patients progressed, resulting in an overall 5-year local tumor control of 95%. The overall 5-year facial nerve preservation probability was 88% and facial nerve neuropathy was statistically significantly higher after SRS, after prior surgery, for larger tumors, and in Koos Grade {>=}3. The overall 5-year trigeminal nerve preservation probability was 96%, not significantly influenced by any of the risk factors. The overall 4-year probability of preservation of useful hearing (Gardner-Robertson score 1 or 2) was 68%, not significantly different between SRS or SRT (59% vs. 82%, p = 0.089, log rank). Conclusion: Linac-based RT results in good local control and acceptable clinical outcome in small to medium-sized vestibular schwannomas (VSs). Radiosurgery for large VSs (Koos Grade {>=}3) remains a challenge because of increased facial nerve neuropathy.

  10. Stereotactic Body Radiotherapy as Primary Treatment for Elderly Patients with Medically Inoperable Head and Neck Cancer

    PubMed Central

    Vargo, John A.; Ferris, Robert L.; Clump, David A.; Heron, Dwight E.

    2014-01-01

    Purpose: With a growing elderly population, elderly patients with head and neck cancers represent an increasing challenge with limited prospective data to guide management. The complex interplay between advanced age, associated co-morbidities, and conventional local therapies, such as surgery and external beam radiotherapy ± chemotherapy, can significantly impact elderly patients’ quality of life (QoL). Stereotactic body radiotherapy (SBRT) is a well-established curative strategy for medical-inoperable early-stage lung cancers even in elderly populations; however, there is limited data examining SBRT as primary therapy in head and neck cancer. Material/methods: Twelve patients with medically inoperable head and neck cancer treated with SBRT ± cetuximab from 2002 to 2013 were retrospectively reviewed. SBRT consisted of primarily 44 Gy in five fractions delivered on alternating days over 1–2 weeks. Concurrent cetuximab was administered at a dose of 400 mg/m2 on day −7 followed by 250 mg/m2 on day 0 and +7 in n = 3 (25%). Patient-reported quality of life (PRQoL) was prospectively recorded using the previously validated University of Washington quality of life revised (UW-QoL-R). Results: Median clinical follow-up was 6 months (range: 0.5–29 months). The 1-year actuarial local progression-free survival, distant progression-free survival, progression-free survival, and overall survival for definitively treated patients were 69, 100, 69, and 64%, respectively. One patient (8%) experienced acute grade 3 dysphagia and one patient (8%) experienced late grade 3 mucositis; there were no grade 4–5 toxicities. Prospective collection of PRQoL as assessed by UW-QoL-R was preserved across domains. Conclusion: Stereotactic body radiotherapy shows encouraging survival and relatively low toxicity in elderly patients with unresectable head and neck cancer, which may provide an aggressive potentially curative local therapy while maintaining QoL. PMID

  11. Stereotactic spine radiosurgery: Review of safety and efficacy with respect to dose and fractionation

    PubMed Central

    Huo, Michael; Sahgal, Arjun; Pryor, David; Redmond, Kristin; Lo, Simon; Foote, Matthew

    2017-01-01

    Background: Stereotactic body radiotherapy (SBRT) is an emerging treatment option for spinal metastases with demonstrated efficacy in the upfront, postoperative, and re-treatment settings, as well as for tumor histologies considered radioresistant. Uncertainty exists regarding the optimal dose and fractionation schedule, with single and multifraction regimens commonly utilized. Methods: A literature search of the PubMed and Medline databases was conducted to identify papers specific to spine SBRT and the effect of varying dose/fractionation regimens on outcomes. Bibliographies of relevant papers were searched for further references, and international spine SBRT experts were consulted. Results: Local control rates generally exceed 80% at 1 year, while high rates of pain control have been attained. There is insufficient evidence to suggest superiority of either single or multiple fraction regimens with respect to local control and pain control. Low rates of toxicity have been reported, assuming strict dose constraints are respected. Radiation myelopathy may be the most morbid toxicity, although the rates are low. The risk of vertebral compression fracture appears to be associated with higher doses per fraction such as those used in single-fraction regimens. The Spinal Instability Neoplastic Score should be considered when evaluating patients for spine SBRT, and prophylactic stabilisation may be warranted. Pain flare is a relatively common toxicity which may be mediated with prophylactic dexamethasone. Because of the treatment complexity and potentially serious toxicities, strict quality assurance should occur at the organizational, planning, dosimetric, and treatment delivery levels. Conclusion: Both single and multifraction regimens are safe and efficacious in spine SBRT for spinal metastases. There may be advantages to hypofractionated treatment over single-fraction regimens with respect to toxicity. Ongoing investigation is underway to define optimal dose and

  12. Preliminary Results of Fractionated Stereotactic Radiotherapy After Cyst Drainage for Craniopharyngioma in Adults

    SciTech Connect

    Kanesaka, Naoto; Mikami, Ryuji; Nakayama, Hidetsugu; Nogi, Sachika; Tajima, Yu; Nakajima, Nobuyuki; Wada, Jun; Miki, Tamotsu; Haraoka, Jou; Okubo, Mitsuru; Sugahara, Shinji; Tokuuye, Koichi

    2012-03-15

    Purpose: To retrospectively evaluate the effectiveness of fractionated stereotactic radiotherapy (FSRT) for craniopharyngioma. Methods and Materials: Between 1999 and 2005, 16 patients with craniopharyngioma were referred to Tokyo Medical University Hospital. They received FSRT alone after histologic confirmation by needle biopsy and underwent cyst drainage via endoscopy. The median prescription dose fraction was 30 Gy in six fractions. All patients except 1 were followed up until December 2009 or death. Results: The median follow-up period was 52 months (range, 4-117 months). Of the 17 patients, 3 experienced recurrence 4 to 71 months after FSRT. The 3-year local control rate was 82.4%. One patient died of thyroid cancer, and the 3-year survival rate was 94.1%. Eight patients had improved visual fields at a median of 2.5 months after FSRT, but hormonal functions did not improve in any patient. Conclusions: FSRT after cyst drainage seems to be safe and effective for patients with craniopharyngiomas, and it may be a safe alternative to surgery.

  13. Pathological characteristics of spine metastases treated with high-dose single-fraction stereotactic radiosurgery.

    PubMed

    Katsoulakis, Evangelia; Laufer, Ilya; Bilsky, Mark; Agaram, Narasimhan P; Lovelock, Michael; Yamada, Yoshiya

    2017-01-01

    OBJECTIVE Spine radiosurgery is increasingly being used to treat spinal metastases. As patients are living longer because of the increasing efficacy of systemic agents, appropriate follow-up and posttreatment management for these patients is critical. Tumor progression after spine radiosurgery is rare; however, vertebral compression fractures are recognized as a more common posttreatment effect. The use of radiographic imaging alone posttreatment may makeit difficult to distinguish tumor progression from postradiation changes such as fibrosis. This is the largest series from a prospective database in which the authors examine histopathology of samples obtained from patients who underwent surgical intervention for presumed tumor progression or mechanical pain secondary to compression fracture. The majority of patients had tumor ablation and resulting fibrosis rather than tumor progression. The aim of this study was to evaluate tumor histopathology and characteristics of patients who underwent pathological sampling because of radiographic tumor progression, fibrosis, or collapsed vertebrae after receiving high-dose single-fraction stereotactic radiosurgery. METHODS Between January 2005 and January 2014, a total of 582 patients were treated with linear accelerator-based single-fraction (18-24 Gy) stereotactic radiosurgery. The authors retrospectively identified 30 patients (5.1%) who underwent surgical intervention for 32 lesions with vertebral cement augmentation for either mechanical pain or instability secondary to vertebral compression fracture (n = 17) or instrumentation (n = 15) for radiographic tumor progression. Radiation and surgical treatment, histopathology, and long-term outcomes were reviewed. Survival and time to recurrence were calculated using the Kaplan-Meier method. RESULTS The mean age at the time of radiosurgery was 59 years (range 36-80 years). The initial pathological diagnoses were obtained for all patients and primarily included radioresistant

  14. Fractionated Stereotactic Radiotherapy Treatment of Cavernous Sinus Meningiomas: A Study of 100 Cases

    SciTech Connect

    Litre, Claude Fabien Colin, Philippe; Noudel, Remy; Peruzzi, Philippe; Bazin, Arnaud; Sherpereel, Bernard; Bernard, Marie Helene; Rousseaux, Pascal

    2009-07-15

    Purpose: We discuss our experiences with fractionated stereotactic radiotherapy (FSR) in the treatment of cavernous sinus meningiomas. Methods and Materials: From 1995 to 2006, we monitored 100 patients diagnosed with cavernous sinus meningiomas; 84 female and 16 male patients were included. The mean patient age was 56 years. The most common symptoms were a reduction in visual acuity (57%), diplopia (50%), exophthalmy (30%), and trigeminal neuralgia (34%). Surgery was initially performed on 26 patients. All patients were treated with FSR. A total of 45 Gy was administered to the lesion, with 5 fractions of 1.8 Gy completed each week. Patient treatment was performed using a Varian Clinac linear accelerator used for cranial treatments and a micro-multileaf collimator. Results: No side effects were reported. Mean follow-up period was 33 months, with 20% of patients undergoing follow-up evaluation of more than 4 years later. The tumor control rate at 3 years was 94%. Three patients required microsurgical intervention because FSR proved ineffective. In terms of functional symptoms, an 81% improvement was observed in patients suffering from exophthalmy, with 46% of these patients being restored to full health. A 52% improvement was observed in diplopia, together with a 67% improvement in visual acuity and a 50% improvement in type V neuropathy. Conclusions: FSR facilitates tumor control, either as an initial treatment option or in combination with microsurgery. In addition to being a safe procedure with few side effects, FSR offers the significant benefit of superior functional outcomes.

  15. Predicting Chest Wall Pain From Lung Stereotactic Body Radiotherapy for Different Fractionation Schemes

    SciTech Connect

    Woody, Neil M.; Videtic, Gregory M.M.; Stephans, Kevin L.; Djemil, Toufik; Kim, Yongbok; Xia Ping

    2012-05-01

    Purpose: Recent studies with two fractionation schemes predicted that the volume of chest wall receiving >30 Gy (V30) correlated with chest wall pain after stereotactic body radiation therapy (SBRT) to the lung. This study developed a predictive model of chest wall pain incorporating radiobiologic effects, using clinical data from four distinct SBRT fractionation schemes. Methods and Materials: 102 SBRT patients were treated with four different fractionations: 60 Gy in three fractions, 50 Gy in five fractions, 48 Gy in four fractions, and 50 Gy in 10 fractions. To account for radiobiologic effects, a modified equivalent uniform dose (mEUD) model calculated the dose to the chest wall with volume weighting. For comparison, V30 and maximum point dose were also reported. Using univariable logistic regression, the association of radiation dose and clinical variables with chest wall pain was assessed by uncertainty coefficient (U) and C statistic (C) of receiver operator curve. The significant associations from the univariable model were verified with a multivariable model. Results: 106 lesions in 102 patients with a mean age of 72 were included, with a mean of 25.5 (range, 12-55) months of follow-up. Twenty patients reported chest wall pain at a mean time of 8.1 (95% confidence interval, 6.3-9.8) months after treatment. The mEUD models, V30, and maximum point dose were significant predictors of chest wall pain (p < 0.0005). mEUD improved prediction of chest wall pain compared with V30 (C = 0.79 vs. 0.77 and U = 0.16 vs. 0.11). The mEUD with moderate weighting (a = 5) better predicted chest wall pain than did mEUD without weighting (a = 1) (C = 0.79 vs. 0.77 and U = 0.16 vs. 0.14). Body mass index (BMI) was significantly associated with chest wall pain (p = 0.008). On multivariable analysis, mEUD and BMI remained significant predictors of chest wall pain (p = 0.0003 and 0.03, respectively). Conclusion: mEUD with moderate weighting better predicted chest wall pain than

  16. Gemcitabine Chemotherapy and Single-Fraction Stereotactic Body Radiotherapy for Locally Advanced Pancreatic Cancer

    SciTech Connect

    Schellenberg, Devin; Goodman, Karyn A.; Lee, Florence; Chang, Stephanie; Kuo, Timothy; Quon, Andrew; Desser, Terry S.; Norton, Jeffrey; Greco, Ralph; Yang, George P.; Koong, Albert C.

    2008-11-01

    Purpose: Fractionated radiotherapy and chemotherapy for locally advanced pancreatic cancer achieves only modest local control. This prospective trial evaluated the efficacy of a single fraction of 25 Gy stereotactic body radiotherapy (SBRT) delivered between Cycle 1 and 2 of gemcitabine chemotherapy. Methods and Materials: A total of 16 patients with locally advanced, nonmetastatic, pancreatic adenocarcinoma received gemcitabine with SBRT delivered 2 weeks after completion of the first cycle. Gemcitabine was resumed 2 weeks after SBRT and was continued until progression or dose-limiting toxicity. The gross tumor volume, with a 2-3-mm margin, was treated in a single 25-Gy fraction by Cyberknife. Patients were evaluated at 4-6 weeks, 10-12 weeks, and every 3 months after SBRT. Results: All 16 patients completed SBRT. A median of four cycles (range one to nine) of chemotherapy was delivered. Three patients (19%) developed local disease progression at 14, 16, and 21 months after SBRT. The median survival was 11.4 months, with 50% of patients alive at 1 year. Patients with normal carbohydrate antigen (CA)19-9 levels either at diagnosis or after Cyberknife SBRT had longer survival (p <0.01). Acute gastrointestinal toxicity was mild, with 2 cases of Grade 2 (13%) and 1 of Grade 3 (6%) toxicity. Late gastrointestinal toxicity was more common, with five ulcers (Grade 2), one duodenal stenosis (Grade 3), and one duodenal perforation (Grade 4). A trend toward increased duodenal volumes radiated was observed in those experiencing late effects (p = 0.13). Conclusion: SBRT with gemcitabine resulted in comparable survival to conventional chemoradiotherapy and good local control. However, the rate of duodenal ulcer development was significant.

  17. Long-term Evaluation of Radiation-Induced Optic Neuropathy After Single-Fraction Stereotactic Radiosurgery

    SciTech Connect

    Leavitt, Jacqueline A.; Stafford, Scott L.; Link, Michael J.; Pollock, Bruce E.

    2013-11-01

    Purpose: To determine the long-term risk of radiation-induced optic neuropathy (RION) in patients having single-fraction stereotactic radiosurgery (SRS) for benign skull base tumors. Methods and Materials: Retrospective review of 222 patients having Gamma Knife radiosurgery for benign tumors adjacent to the anterior visual pathway (AVP) between 1991 and 1999. Excluded were patients with prior or concurrent external beam radiation therapy or SRS. One hundred twenty-nine patients (58%) had undergone previous surgery. Tumor types included confirmed World Health Organization grade 1 or presumed cavernous sinus meningioma (n=143), pituitary adenoma (n=72), and craniopharyngioma (n=7). The maximum dose to the AVP was ≤8.0 Gy (n=126), 8.1-10.0 Gy (n=39), 10.1-12.0 Gy (n=47), and >12 Gy (n=10). Results: The mean clinical and imaging follow-up periods were 83 and 123 months, respectively. One patient (0.5%) who received a maximum radiation dose of 12.8 Gy to the AVP developed unilateral blindness 18 months after SRS. The chance of RION according to the maximum radiation dose received by the AVP was 0 (95% confidence interval [CI] 0-3.6%), 0 (95% CI 0-10.7%), 0 (95% CI 0-9.0%), and 10% (95% CI 0-43.0%) for patients receiving ≤8 Gy, 8.1-10.0 Gy, 10.1-12.0 Gy, and >12 Gy, respectively. The overall risk of RION in patients receiving >8 Gy to the AVP was 1.0% (95% CI 0-6.2%). Conclusions: The risk of RION after single-fraction SRS in patients with benign skull base tumors who have no prior radiation exposure is very low if the maximum dose to the AVP is ≤12 Gy. Physicians performing single-fraction SRS should remain cautious when treating lesions adjacent to the AVP, especially when the maximum dose exceeds 10 Gy.

  18. Fractionated Stereotactic Radiosurgery for Reirradiation of Head-and-Neck Cancer

    SciTech Connect

    Unger, Keith R.; Lominska, Christopher E.; Deeken, John F.

    2010-08-01

    Purpose: Stereotactic radiosurgery (SRS) is an appealing treatment option after previous radiotherapy because of its precision, conformality, and reduced treatment duration. We report our experience with reirradiation using fractionated SRS for head-and-neck cancer. Methods and Materials: From 2002 to 2008, 65 patients received SRS to the oropharynx (n = 13), hypopharynx (n = 8), nasopharynx (n = 7), paranasal sinus (n = 7), neck (n = 7), and other sites (n = 23). Thirty-eight patients were treated definitively and 27 patients with metastatic disease and/or untreated local disease were treated palliatively. Nine patients underwent complete macroscopic resection before SRS. Thirty-three patients received concurrent chemoradiation. The median initial radiation dose was 67 Gy, and the median reirradiation SRS dose was 30 Gy (21-35 Gy) in 2-5 fractions. Results: Median follow-up for surviving patients was 16 months. Fifty-six patients were evaluable for response: 30 (54%) had complete, 15 (27%) had partial, and 11 (20%) had no response. Median overall survival (OS) for all patients was 12 months. For definitively treated patients, the 2-year OS and locoregional control (LRC) rates were 41% and 30%, respectively. Multivariate analysis demonstrated that higher total dose, surgical resection, and nasopharynx site were significantly associated with improved LRC; surgical resection and nonsquamous histology were associated with improved OS. Seven patients (11%) experienced severe reirradiation-related toxicity, including one treatment-attributed death. Conclusion: SRS reirradiation for head-and-neck cancer is feasible. This study demonstrates encouraging response rates with acceptable toxicity. Fractionated SRS reirradiation with concurrent chemotherapy in select patients warrants further study.

  19. Dose-Response Modeling of the Visual Pathway Tolerance to Single-Fraction and Hypofractionated Stereotactic Radiosurgery.

    PubMed

    Hiniker, Susan M; Modlin, Leslie A; Choi, Clara Y; Atalar, Banu; Seiger, Kira; Binkley, Michael S; Harris, Jeremy P; Liao, Yaping Joyce; Fischbein, Nancy; Wang, Lei; Ho, Anthony; Lo, Anthony; Chang, Steven D; Harsh, Griffith R; Gibbs, Iris C; Hancock, Steven L; Li, Gordon; Adler, John R; Soltys, Scott G

    2016-04-01

    Patients with tumors adjacent to the optic nerves and chiasm are frequently not candidates for single-fraction stereotactic radiosurgery (SRS) due to concern for radiation-induced optic neuropathy. However, these patients have been successfully treated with hypofractionated SRS over 2-5 days, though dose constraints have not yet been well defined. We reviewed the literature on optic tolerance to radiation and constructed a dose-response model for visual pathway tolerance to SRS delivered in 1-5 fractions. We analyzed optic nerve and chiasm dose-volume histogram (DVH) data from perioptic tumors, defined as those within 3mm of the optic nerves or chiasm, treated with SRS from 2000-2013 at our institution. Tumors with subsequent local progression were excluded from the primary analysis of vision outcome. A total of 262 evaluable cases (26 with malignant and 236 with benign tumors) with visual field and clinical outcomes were analyzed. Median patient follow-up was 37 months (range: 2-142 months). The median number of fractions was 3 (1 fraction n = 47, 2 fraction n = 28, 3 fraction n = 111, 4 fraction n = 10, and 5 fraction n = 66); doses were converted to 3-fraction equivalent doses with the linear quadratic model using α/β = 2Gy prior to modeling. Optic structure dose parameters analyzed included Dmin, Dmedian, Dmean, Dmax, V30Gy, V25Gy, V20Gy, V15Gy, V10Gy, V5Gy, D50%, D10%, D5%, D1%, D1cc, D0.50cc, D0.25cc, D0.20cc, D0.10cc, D0.05cc, D0.03cc. From the plan DVHs, a maximum-likelihood parameter fitting of the probit dose-response model was performed using DVH Evaluator software. The 68% CIs, corresponding to one standard deviation, were calculated using the profile likelihood method. Of the 262 analyzed, 2 (0.8%) patients experienced common terminology criteria for adverse events grade 4 vision loss in one eye, defined as vision of 20/200 or worse in the affected eye. One of these patients had received 2 previous courses of radiotherapy to the optic structures

  20. Stereotactic Body Radiation Therapy for Primary, Recurrent, and Metastatic Tumors in the Head-and-Neck Region

    SciTech Connect

    Siddiqui, Farzan; Patel, Mehul; Khan, Mumtaz; McLean, Scott; Dragovic, Jadranka; Jin, J.-Y.; Movsas, Benjamin; Ryu, Samuel

    2009-07-15

    Purpose: To determine the feasibility, safety, and efficacy of stereotactic body radiation therapy (SBRT), also known as radiosurgery, in patients with head-and-neck cancers. Methods and Materials: Patients with pathologically proven malignant lesions in the head-and-neck region were treated using single-dose SBRT (S-SBRT) or fractionated SBRT (F-SBRT). Radiation doses were either single-fraction 13-18 Gy for S-SBRT or 36-48 Gy in five to eight fractions for F-SBRT. Response evaluation was based on clinical examinations and computed tomography/magnetic resonance imaging scans. Pre- and post-SBRT tumor dimensions were measured in three axes, and tumor volumes were calculated. Response evaluation also was performed using World Health Organization criteria. Results: Fifty-five lesions were treated in 44 patients (25 men, 19 women). There were three groups of patients: those with primary (n = 10), recurrent (n = 21), and metastatic tumors (n = 13). The predominant histologic type was squamous cell carcinoma (n = 33). The majority of lesions were treated using F-SBRT (n = 37). Based on radiographic and clinical assessment, a 77% (complete + partial response) response rate was noted. Percentage of reduction in tumor volume was 52% {+-} 38% based on follow-up scans in 24 patients. Tumor control rates at 1 year were 83.3% and 60.6% in the primary and recurrent groups, respectively. Median overall survival was 28.7, 6.7, and 5.6 months for the primary, recurrent, and metastatic groups, respectively. Radiation Therapy Oncology Group Grade 1-2 mucositis was noted in all patients treated for oropharyngeal or laryngeal lesions. Conclusions: The SBRT in single or fractionated doses offers a viable treatment option for selected patients with primary, recurrent, and metastatic head-and-neck cancers with functional preservation.

  1. Peripheral nervous system injury after high-dose single-fraction image-guided stereotactic radiosurgery for spine tumors.

    PubMed

    Stubblefield, Michael D; Ibanez, Katarzyna; Riedel, Elyn R; Barzilai, Ori; Laufer, Ilya; Lis, Eric; Yamada, Yoshiya; Bilsky, Mark H

    2017-03-01

    OBJECTIVE The object of this study was to determine the percentage of high-dose (1800-2600 cGy) single-fraction stereotactic radiosurgery (SF-SRS) treatments to the spine that result in peripheral nervous system (PNS) injury. METHODS All patients treated with SF-SRS for primary or metastatic spine tumors between January 2004 and May 2013 and referred to the Rehabilitation Medicine Service for evaluation and treatment of neuromuscular, musculoskeletal, or functional impairments or pain were retrospectively identified. RESULTS Five hundred fifty-seven SF-SRS treatments in 447 patients resulted in 14 PNS injuries in 13 patients. All injures resulted from SF-SRS delivered to the cervical or lumbosacral spine at 2400 cGy. The overall percentage of SF-SRS treatments resulting in PNS injury was 2.5%, increasing to 4.5% when the thoracic spine was excluded from analysis. The median time to symptom onset following SF-SRS was 10 months (range 4-32 months). The plexus (cervical, brachial, and/or lumbosacral) was affected clinically and/or electrophysiologically in 12 (86%) of 14 cases, the nerve root in 2 (14%) of 14, and both in 6 (43%) of 14 cases. All patients experienced pain and most (93%) developed weakness. Peripheral nervous system injuries were CTCAE Grade 1 in 14% of cases, 2 in 64%, and 3 in 21%. No dose relationship between SF-SRS dose and PNS injury was detected. CONCLUSIONS Single-fraction SRS to the spine can result in PNS injury with major implications for function and quality of life.

  2. Fractionated stereotactic radiotherapy boost for gynecologic tumors: An alternative to brachytherapy?

    SciTech Connect

    Molla, Meritxell; Escude, Lluis D.; Nouet, Philippe; Popowski, Youri D.Sc.; Hidalgo, Alberto; Rouzaud, Michel; Linero, Dolores; Miralbell, Raymond . E-mail: Raymond.Miralbell@hcuge.ch

    2005-05-01

    Purpose: A brachytherapy (BT) boost to the vaginal vault is considered standard treatment for many endometrial or cervical cancers. We aimed to challenge this treatment standard by using stereotactic radiotherapy (SRT) with a linac-based micromultileaf collimator technique. Methods and Materials: Since January 2002, 16 patients with either endometrial (9) or cervical (7) cancer have been treated with a final boost to the areas at higher risk for relapse. In 14 patients, the target volume included the vaginal vault, the upper vagina, the parametria, or (if not operated) the uterus (clinical target volume [CTV]). In 2 patients with local relapse, the CTV was the tumor in the vaginal stump. Margins of 6-10 mm were added to the CTV to define the planning target volume (PTV). Hypofractionated dynamic-arc or intensity-modulated radiotherapy techniques were used. Postoperative treatment was delivered in 12 patients (2 x 7 Gy to the PTV with a 4-7-day interval between fractions). In the 4 nonoperated patients, a dose of 4 Gy/fraction in 5 fractions with 2 to 3 days' interval was delivered. Patients were immobilized in a customized vacuum body cast and optimally repositioned with an infrared-guided system developed for extracranial SRT. To further optimize daily repositioning and target immobilization, an inflated rectal balloon was used during each treatment fraction. In 10 patients, CT resimulation was performed before the last boost fraction to assess for repositioning reproducibility via CT-to-CT registration and to estimate PTV safety margins around the CTV. Finally, a comparative treatment planning study between BT and SRT was performed in 2 patients with an operated endometrial Stage I cancer. Results: No patient developed severe acute urinary or low-intestinal toxicity. No patient developed urinary late effects (>6 months). One patient with a vaginal relapse previously irradiated to the pelvic region presented with Grade 3 rectal bleeding 18 months after retreatment

  3. Integration of surgery with fractionated stereotactic radiotherapy for treatment of nonfunctioning pituitary macroadenomas

    SciTech Connect

    Paek, Sun Ha; Downes, M. Beverly; Bednarz, Greg; Keane, William M.; Werner-Wasik, Maria; Curran, Walter J.; Andrews, David W. . E-mail: david.andrews@jefferson.edu

    2005-03-01

    Objective: To evaluate the efficacy of fractionated stereotactic radiotherapy (FSRT) after surgery in the management of residual or recurrent nonfunctioning pituitary adenomas with respect to tumor control and the development of complications. Methods and materials: The clinical records of patients with nonfunctioning pituitary adenomas who underwent FSRT were retrospectively analyzed. For newly diagnosed tumors, transsphenoidal surgery was performed, and, if residual tumor was identified at 3 months, FSRT was performed. If significant tumor volume persisted, transcranial surgery was performed before FSRT. We originally initiated FSRT with 2-Gy fractions to 46 Gy. We escalated the dose to 50.4 Gy thereafter. As a final modification, we dropped the daily dose to 1.8-Gy fractions delivered within 6 weeks. High-dose conformality and homogeneity was achieved with arc beam shaping and differential beam weighting. The radiographic, endocrinologic, and visual outcomes after FSRT were evaluated. Results: The 68 patients included 36 males and 32 females with an age range of 15-81 years. The median follow-up was 30 months (range, 2-82 months), and the median tumor volume was 6.2 cm{sup 3}. Of the 68 patients, 20 were treated to 46 Gy and 48 to 50-52.2 Gy. Most were treated to 50.4 Gy. Eleven patients had recurrent tumors, 54 had residual tumors, and no surgery was performed in 3 patients before FSRT. We noted no radiation-induced acute or late toxicities, except for radiation-induced optic neuropathy in 2 patients. At latest follow-up, the tumor had decreased in size in 26 patients and remained stable in 41 of the 42 remaining patients. Of the 68 patients, 4 (6%) developed hypopituitarism at 6, 11, 12, and 17 months after FSRT. Reviewing available serial Humphrey visual fields, visual fields were objectively improved in 28 patients, and remained stable in 24 patients, and worsened in 2 patients. Conclusion: The findings of this analysis support the use of surgery followed by

  4. Esophageal Toxicity From High-Dose, Single-Fraction Paraspinal Stereotactic Radiosurgery

    SciTech Connect

    Cox, Brett W.; Jackson, Andrew; Hunt, Margie; Bilsky, Mark; Yamada, Yoshiya

    2012-08-01

    Purpose: To report the esophageal toxicity from single-fraction paraspinal stereotactic radiosurgery (SRS) and identify dosimetric and clinical risk factors for toxicity. Methods and Materials: A total of 204 spinal metastases abutting the esophagus (182 patients) were treated with high-dose single-fraction SRS during 2003-2010. Toxicity was scored using the National Cancer Institute Common Toxicity Criteria for Adverse Events, version 4.0. Dose-volume histograms were combined to generate a comprehensive atlas of complication incidence that identifies risk factors for toxicity. Correlation of dose-volume factors with esophageal toxicity was assessed using Fisher's exact test and logistic regression. Clinical factors were correlated with toxicity. Results: The median dose to the planning treatment volume was 24 Gy. Median follow-up was 12 months (range, 3-81). There were 31 (15%) acute and 24 (12%) late esophageal toxicities. The rate of grade {>=}3 acute or late toxicity was 6.8% (14 patients). Fisher's exact test resulted in significant median splits for grade {>=}3 toxicity at V12 = 3.78 cm{sup 3} (relative risk [RR] 3.7, P=.05), V15 = 1.87 cm{sup 3} (RR 13, P=.0013), V20 = 0.11 cm{sup 3} (RR 6, P=0.01), and V22 = 0.0 cm{sup 3} (RR 13, P=.0013). The median split for D2.5 cm{sup 3} (14.02 Gy) was also a significant predictor of toxicity (RR 6; P=.01). A highly significant logistic regression model was generated on the basis of D2.5 cm{sup 3}. One hundred percent (n = 7) of grade {>=}4 toxicities were associated with radiation recall reactions after doxorubicin or gemcitabine chemotherapy or iatrogenic manipulation of the irradiated esophagus. Conclusions: High-dose, single-fraction paraspinal SRS has a low rate of grade {>=}3 esophageal toxicity. Severe esophageal toxicity is minimized with careful attention to esophageal doses during treatment planning. Iatrogenic manipulation of the irradiated esophagus and systemic agents classically associated with radiation

  5. Quality Assessment of Frameless Fractionated Stereotactic Radiotherapy Using Cone Beam Computed Tomography

    SciTech Connect

    Peng, Lee-Cheng; Kahler, Darren; Samant, Sanjiv; Li, Jonathan; Amdur, Robert; Palta, Jatinder R.; Liu, Chihray

    2010-12-01

    Purpose: A quality assessment of intracranial stereotactic radiotherapy was performed using cone beam computed tomography (CBCT). Setup errors were analyzed for two groups of patients: (1) those who were positioned using a frameless SonArray (FSA) system and immobilized with a bite plate and thermoplastic (TP) mask (the bFSA group); and (2) those who were positioned by room laser and immobilized using a TP mask (the mLAS group). Methods and Materials: A quality assurance phantom was used to study the system differences between FSA and CBCT. The quality assessment was performed using an Elekta Synergy imager (XVI) (Elekta Oncology Systems, Norcross, GA) and an On-Board Imager (OBI) (Varian Medical Systems, Palo Alto, CA) for 25 patients. For the first three fractions, and weekly thereafter, the FSA system was used for patient positioning, after which CBCT was performed to obtain setup errors. Results: (1) Phantom tests: The mean differences in the isocenter displacements for the two systems was 1.2 {+-} 0.7 mm. No significant variances were seen between the XVI and OBI units (p{approx}0.208). (2)Patient tests: The mean of the displacements between FSA and CBCT were independent of the CBCT system used; mean setup errors for the bFSA group were smaller (1.2 mm) than those of the mLAS group (3.2 mm) (p < 0.005). For the mLAS patients, the 90th percentile and the maximum rotational displacements were 3{sup o} and 5{sup o}, respectively. A 4-mm drift in setup accuracy occurred over the treatment course for 1 bFSA patient. Conclusions: System differences of less than 1 mm between CBCT and FSA were seen. Error regression was observed for the bFSA patients, using CBCT (up to 4 mm) during the treatment course. For the mLAS group, daily CBCT imaging was needed to obtain acceptable setup accuracies.

  6. SU-F-BRF-12: Investigating Dosimetric Effects of Inter-Fraction Deformation in Lung Cancer Stereotactic Body Radiotherapy (SBRT)

    SciTech Connect

    Jia, J; Tian, Z; Gu, X; Yan, H; Jia, X; Jiang, S

    2014-06-15

    Purpose: We studied dosimetric effects of inter-fraction deformation in lung stereotactic body radiotherapy (SBRT), in order to investigate the necessity of adaptive re-planning for lung SBRT treatments. Methods: Six lung cancer patients with different treatment fractions were retrospectively investigated. All the patients were immobilized and localized with a stereotactic body frame and were treated under cone-beam CT (CBCT) image guidance at each fraction. We calculated the actual delivered dose of the treatment plan using the up-to-date patient geometry of each fraction, and compared the dose with the intended plan dose to investigate the dosimetric effects of the inter-fraction deformation. Deformable registration was carried out between the treatment planning CT and the CBCT of each fraction to obtain deformed planning CT for more accurate dose calculations of the delivered dose. The extent of the inter-fraction deformation was also evaluated by calculating the dice similarity coefficient between the delineated structures on the planning CT and those on the deformed planning CT. Results: The average dice coefficients for PTV, spinal cord, esophagus were 0.87, 0.83 and 0.69, respectively. The volume of PTV covered by prescription dose was decreased by 23.78% on average for all fractions and all patients. For spinal cord and esophagus, the volumes covered by the constraint dose were increased by 4.57% and 3.83%. The maximum dose was also increased by 4.11% for spinal cord and 4.29% for esophagus. Conclusion: Due to inter-fraction deformation, large deterioration was found in both PTV coverage and OAR sparing, which demonstrated the needs for adaptive re-planning of lung SBRT cases to improve target coverage while reducing radiation dose to nearby normal tissues.

  7. Report on a randomized trial comparing two forms of immobilization of the head for fractionated stereotactic radiotherapy.

    PubMed

    Bednarz, Greg; Machtay, Mitchell; Werner-Wasik, Maria; Downes, Beverly; Bogner, Joachim; Hyslop, Terry; Galvin, James; Evans, James; Curran, Walter; Andrews, David

    2009-01-01

    Fractionated stereotactic radiotherapy (SRT) requires accurate and reproducible immobilization of the patient's head. This randomized study compared the efficacy of two commonly used forms of immobilization used for SRT. Two routinely used methods of immobilization, which differ in their approach to reproduce the head position from day to day, are the Gill-Thomas-Cosman (GTC) frame and the BrainLab thermoplastic mask. The GTC frame fixates on the patient's upper dentition and thus is in direct mechanical contact with the cranium. The BrainLab mask is a two-part masking system custom fitted to the front and back of the patient's head. After patients signed an IRB-approved informed consent form, eligible patients were randomized to either GTC frame or mask for their course of SRT. Patients were treated as per standard procedure; however, prior to each treatment a set of digital kilovolt images (ExacTrac, BrainLabAB, Germany) was taken. These images were fused with reference digitally reconstructed radiographs obtained from treatment planning CT to yield lateral, longitudinal, and vertical deviations of isocenter and head rotations about respective axes. The primary end point of the study was to compare the two systems with respect to mean and standard deviations using the distance to isocenter measure. A total of 84 patients were enrolled (69 patients evaluable with detailed positioning data). A mixed-effect linear regression and two-tiled t test were used to compare the distance measure for both the systems. There was a statistically significant (p < 0.001) difference between mean distances for these systems, suggesting that the GTC frame was more accurate. The mean 3D displacement and standard deviations were 3.17+1.95 mm for mask and 2.00+1.04 mm for frame. Both immobilization techniques were highly effective, but the GTC frame was more accurate. To optimize the accuracy of SRT, daily kilovolt image guidance is recommended with either immobilization system.

  8. Report on a randomized trial comparing two forms of immobilization of the head for fractionated stereotactic radiotherapy

    SciTech Connect

    Bednarz, Greg; Machtay, Mitchell; Werner-Wasik, Maria; Downes, Beverly; Bogner, Joachim; Hyslop, Terry; Galvin, James; Evans, James; Curran, Walter Jr.; Andrews, David

    2009-01-15

    Fractionated stereotactic radiotherapy (SRT) requires accurate and reproducible immobilization of the patient's head. This randomized study compared the efficacy of two commonly used forms of immobilization used for SRT. Two routinely used methods of immobilization, which differ in their approach to reproduce the head position from day to day, are the Gill-Thomas-Cosman (GTC) frame and the BrainLab thermoplastic mask. The GTC frame fixates on the patient's upper dentition and thus is in direct mechanical contact with the cranium. The BrainLab mask is a two-part masking system custom fitted to the front and back of the patient's head. After patients signed an IRB-approved informed consent form, eligible patients were randomized to either GTC frame or mask for their course of SRT. Patients were treated as per standard procedure; however, prior to each treatment a set of digital kilovolt images (ExacTrac, BrainLabAB, Germany) was taken. These images were fused with reference digitally reconstructed radiographs obtained from treatment planning CT to yield lateral, longitudinal, and vertical deviations of isocenter and head rotations about respective axes. The primary end point of the study was to compare the two systems with respect to mean and standard deviations using the distance to isocenter measure. A total of 84 patients were enrolled (69 patients evaluable with detailed positioning data). A mixed-effect linear regression and two-tiled t test were used to compare the distance measure for both the systems. There was a statistically significant (p<0.001) difference between mean distances for these systems, suggesting that the GTC frame was more accurate. The mean 3D displacement and standard deviations were 3.17+1.95 mm for mask and 2.00+1.04 mm for frame. Both immobilization techniques were highly effective, but the GTC frame was more accurate. To optimize the accuracy of SRT, daily kilovolt image guidance is recommended with either immobilization system.

  9. SU-E-J-187: Management of Optic Organ Motion in Fractionated Stereotactic Radiotherapy

    SciTech Connect

    Manning, M; Maurer, J

    2015-06-15

    Purpose: Fractionated stereotactic radiotherapy (FSRT) for optic nerve tumors can potentially use planning target volume (PTV) expansions as small as 1–5 mm. However, the motion of the intraorbital segment of the optic nerve has not been studied. Methods: A subject with a right optic nerve sheath meningioma underwent CT simulation in three fixed gaze positions: right, left, and fixed forward at a marker. The gross tumor volume (GTV) and the organs-at-risk (OAR) were contoured on all three scans. An IMRT plan using 10 static non-coplanar fields to 50.4 Gy in 28 fractions was designed to treat the fixed-forward gazing GTV with a 1 mm PTV, then resulting coverage was evaluated for the GTV in the three positions. As an alternative, the composite structures were computed to generate the internal target volume (ITV), 1 mm expansion free-gazing PTV, and planning organat-risk volumes (PRVs) for free-gazing treatment. A comparable IMRT plan was created for the free-gazing PTV. Results: If the patient were treated using the fixed forward gaze plan looking straight, right, and left, the V100% for the GTV was 100.0%, 33.1%, and 0.1%, respectively. The volumes of the PTVs for fixed gaze and free-gazing plans were 0.79 and 2.21 cc, respectively, increasing the PTV by a factor of 2.6. The V100% for the fixed gaze and free-gazing plans were 0.85 cc and 2.8 cc, respectively increasing the treated volume by a factor of 3.3. Conclusion: Fixed gaze treatment appears to provide greater organ sparing than free-gazing. However unanticipated intrafraction right or left gaze can produce a geometric miss. Further study of optic nerve motion appears to be warranted in areas such as intrafraction optical confirmation of fixed gaze and optimized gaze directions to minimize lens and other normal organ dose in cranial radiotherapy.

  10. Stereotactic Fractionated Radiotherapy and LINAC Radiosurgery in the Treatment of Vestibular Schwannoma-Report About Both Stereotactic Methods From a Single Institution

    SciTech Connect

    Kopp, Christine; Fauser, Claudius; Mueller, Axel; Astner, Sabrina T.; Jacob, Vesna; Lumenta, Christianto; Meyer, Bernhard; Tonn, Joerg-Christian; Molls, Michael; Grosu, Anca-Ligia

    2011-08-01

    Purpose: To evaluate tumor control and side effects associated with radiosurgery (RS) and stereotactic fractionated radiotherapy (SFR) for vestibular schwannomas (VSs) in a group of patients treated at the same institution. Methods and Materials: Between May 1997 and June 2007, 115 consecutive cases of VS were treated in our department. The SFR group (47 patients), including larger tumors (maximum diameter >1.5 cm), received a total dose of 54 Gy at 1.8 Gy per fraction. The RS group (68 patients, maximum diameter <1.5 cm) received a total dose of 12 Gy at the 100% isodose. Evaluation included serial imaging tests (magnetic resonance imaging) and neurologic and functional hearing examinations. Results: The tumor control rate was 97.9% in the SFR group for a mean follow-up time of 32.1 months and 98.5% in the RS group for a mean follow-up time of 30.1 months. Hearing function was preserved after RS in 85% of the patients and after SFR in 79%. Facial and trigeminal nerve function remained mostly unaffected after SFR. After RS, new trigeminal neuropathy occurred in 9 of 68 patients (13%). Conclusions: A high tumor control rate and low number of side effects are registered after SFR and RS of VS. These results confirm that considering tumor diameter, both RS and SFR are good treatment modalities for VS.

  11. Differences in Clinical Results After LINAC-Based Single-Dose Radiosurgery Versus Fractionated Stereotactic Radiotherapy for Patients With Vestibular Schwannomas

    SciTech Connect

    Combs, Stephanie E.; Welzel, Thomas; Schulz-Ertner, Daniela; Huber, Peter E.; Debus, Juergen

    2010-01-15

    Purpose: To evaluate the outcomes of patients with vestibular schwannoma (VS) treated with fractionated stereotactic radiotherapy (FSRT) vs. those treated with stereotactic radiosurgery (SRS). Methods and Materials: This study is based on an analysis of 200 patients with 202 VSs treated with FSRT (n = 172) or SRS (n = 30). Patients with tumor progression and/or progression of clinical symptoms were selected for treatment. In 165 out of 202 VSs (82%), RT was performed as the primary treatment for VS, and for 37 VSs (18%), RT was conducted for tumor progression after neurosurgical intervention. For patients receiving FSRT, a median total dose of 57.6 Gy was prescribed, with a median fractionation of 5 x 1.8 Gy per week. For patients who underwent SRS, a median single dose of 13 Gy was prescribed to the 80% isodose. Results: FSRT and SRS were well tolerated. Median follow-up time was 75 months. Local control was not statistically different for both groups. The probability of maintaining the pretreatment hearing level after SRS with doses of <=13 Gy was comparable to that of FSRT. The radiation dose for the SRS group (<=13 Gy vs. >13 Gy) significantly influenced hearing preservation rates (p = 0.03). In the group of patients treated with SRS doses of <=13 Gy, cranial nerve toxicity was comparable to that of the FSRT group. Conclusions: FSRT and SRS are both safe and effective alternatives for the treatment of VS. Local control rates are comparable in both groups. SRS with doses of <=13 Gy is a safe alternative to FSRT. While FSRT can be applied safely for the treatment of VSs of all sizes, SRS should be reserved for smaller lesions.

  12. Stereotactic Ablative Body Radiation Therapy for Primary Kidney Cancer: A 3-Dimensional Conformal Technique Associated With Low Rates of Early Toxicity

    SciTech Connect

    Pham, Daniel; Thompson, Ann; Kron, Tomas; Foroudi, Farshad; Kolsky, Michal Schneider; Devereux, Thomas; Lim, Andrew; Siva, Shankar

    2014-12-01

    Purpose: To describe our 3-dimensional conformal planning approaches and report early toxicities with stereotactic body radiation therapy for the management of primary renal cell carcinoma. Methods and Materials: This is an analysis of a phase 1 trial of stereotactic body radiation therapy for primary inoperable renal cell carcinoma. A dose of 42 Gy/3 fractions was prescribed to targets ≥5 cm, whereas for <5 cm 26 Gy/1 fraction was used. All patients underwent a planning 4-dimensional CT to generate a planning target volume (PTV) from a 5-mm isotropic expansion of the internal target volume. Planning required a minimum of 8 fields prescribing to the minimum isodose surrounding the PTV. Intermediate dose spillage at 50% of the prescription dose (R50%) was measured to describe the dose gradient. Early toxicity (<6 months) was scored using the Common Terminology Criteria for Adverse Events (v4.0). Results: From July 2012 to August 2013 a total of 20 patients (median age, 77 years) were recruited into a prospective clinical trial. Eleven patients underwent fractionated treatment and 9 patients a single fraction. For PTV targets <100 cm{sup 3} the median number of beams used was 8 (2 noncoplanar) to achieve an average R50% of 3.7. For PTV targets >100 cm{sup 3} the median beam number used was 10 (4 noncoplanar) for an average R50% value of 4.3. The R50% was inversely proportional to decreasing PTV volume (r=−0.62, P=.003) and increasing total beams used (r=−0.51, P=.022). Twelve of 20 patients (60%) suffered grade ≤2 early toxicity, whereas 8 of 20 patients (40%) were asymptomatic. Nausea, chest wall pain, and fatigue were the most common toxicities reported. Conclusion: A 3-dimensional conformal planning technique of 8-10 beams can be used to deliver highly tolerable stereotactic ablation to primary kidney targets with minimal early toxicities. Ongoing follow-up is currently in place to assess long-term toxicities and cancer control.

  13. Six-Dimensional Correction of Intra-Fractional Prostate Motion with CyberKnife Stereotactic Body Radiation Therapy.

    PubMed

    Lei, Siyuan; Piel, Nathaniel; Oermann, Eric K; Chen, Viola; Ju, Andrew W; Dahal, Kedar N; Hanscom, Heather N; Kim, Joy S; Yu, Xia; Zhang, Guowei; Collins, Brian T; Jha, Reena; Dritschilo, Anatoly; Suy, Simeng; Collins, Sean P

    2011-01-01

    Large fraction radiation therapy offers a shorter course of treatment and radiobiological advantages for prostate cancer treatment. The CyberKnife is an attractive technology for delivering large fraction doses based on the ability to deliver highly conformal radiation therapy to moving targets. In addition to intra-fractional translational motion (left-right, superior-inferior, and anterior-posterior), prostate rotation (pitch, roll, and yaw) can increase geographical miss risk. We describe our experience with six-dimensional (6D) intra-fraction prostate motion correction using CyberKnife stereotactic body radiation therapy (SBRT). Eighty-eight patients were treated by SBRT alone or with supplemental external radiation therapy. Trans-perineal placement of four gold fiducials within the prostate accommodated X-ray guided prostate localization and beam adjustment. Fiducial separation and non-overlapping positioning permitted the orthogonal imaging required for 6D tracking. Fiducial placement accuracy was assessed using the CyberKnife fiducial extraction algorithm. Acute toxicities were assessed using Common Toxicity Criteria v3. There were no Grade 3, or higher, complications and acute morbidity was minimal. Ninety-eight percent of patients completed treatment employing 6D prostate motion tracking with intra-fractional beam correction. Suboptimal fiducial placement limited treatment to 3D tracking in two patients. Our experience may guide others in performing 6D correction of prostate motion with CyberKnife SBRT.

  14. Clinical applicability of biologically effective dose calculation for spinal cord in fractionated spine stereotactic body radiation therapy

    PubMed Central

    Lee, Seung Heon; Lee, Kyu Chan; Choi, Jinho; Ahn, So Hyun; Lee, Seok Ho; Sung, Ki Hoon; Kil, Se Hee

    2015-01-01

    Background. The aim of the study was to investigate whether biologically effective dose (BED) based on linear-quadratic model can be used to estimate spinal cord tolerance dose in spine stereotactic body radiation therapy (SBRT) delivered in 4 or more fractions. Patients and methods. Sixty-three metastatic spinal lesions in 47 patients were retrospectively evaluated. The most frequently prescribed dose was 36 Gy in 4 fractions. In planning, we tried to limit the maximum dose to the spinal cord or cauda equina less than 50% of prescription or 45 Gy2/2. BED was calculated using maximum point dose of spinal cord. Results. Maximum spinal cord dose per fraction ranged from 2.6 to 6.0 Gy (median 4.3 Gy). Except 4 patients with 52.7, 56.4, 62.4, and 67.9 Gy2/2, equivalent total dose in 2-Gy fraction of the patients was not more than 50 Gy2/2 (12.1–67.9, median 32.0). The ratio of maximum spinal cord dose to prescription dose increased up to 82.2% of prescription dose as epidural spinal cord compression grade increased. No patient developed grade 2 or higher radiation-induced spinal cord toxicity during follow-up period of 0.5 to 53.9 months. Conclusions. In fractionated spine SBRT, BED can be used to estimate spinal cord tolerance dose, provided that the dose per fraction to the spinal cord is moderate, e.g. < 6.0 Gy. It appears that a maximum dose of up to 45–50 Gy2/2 to the spinal cord is tolerable in 4 or more fractionation regimen. PMID:26029031

  15. [Stereotactic radiosurgery and radiotherapy for brain metastases].

    PubMed

    Tanguy, Ronan; Métellus, Philippe; Mornex, Françoise; Mazeron, Jean-Jacques

    2013-01-01

    Brain metastases management is still controversial even though many trials are trying to define the respective roles of neurosurgery, whole-brain radiotherapy, single-dose stereotactic radiotherapy and fractionated stereotactic radiotherapy. In this article, we review data from trials that examine the role of radiosurgery and fractionated stereotactic radiotherapy in the management of brain metastases.

  16. Clinical outcomes of CyberKnife stereotactic radiosurgery for elderly patients with presumed primary stage I lung cancer

    PubMed Central

    Wang, Zhen; Li, Ao-Mei; Gao, Jie; Li, Jing; Li, Bing; Lee, Percy; Simone, Charles B.; Song, Yong

    2017-01-01

    Background In certain situations, especially in the elderly patient population, a tissue diagnosis of a suspected pulmonary neoplasm is not feasible. Often, a definitive treatment such as stereotactic body radiosurgery is recommended, rather than active surveillance. The aim of this study is to evaluate the efficacy and tolerability of stereotactic body radiotherapy (SBRT) for elderly patients with presumed primary stage I lung cancer without pathological tissue confirmation. Methods We performed a retrospective analysis of 25 elderly patients (≥75 years) with presumed primary stage I lung cancer treated with SBRT from 2009–2015. The primary end point was local control (LC); secondary end points were survival and toxicity. Results The median follow-up (FU) was 36.0 months (range, 4 to 84 months). The 1-year LC rate was 100%, 3-year LC rate was 78.8%, and 5-year LC rate was 65.7%. The median progression-free survival (PFS) time was 48.0 months (95% CI: 31.2–64.8). The 1-, 3-, and 5-year overall survival (OS) rates were 96.0%, 70.2%, and 50.7%, respectively. The 1-, 3-, and 5-year cancer-specific survival (CSS) rates were 100%, 81.3%, and 67.0%, respectively. No grade 4 or higher toxicity was encountered. Conclusions SBRT is safe and effective treatment for patients with presumed primary stage I lung cancer where obtaining pathological confirmation of malignancy is challenging. PMID:28331819

  17. Fractionated stereotactic radiotherapy: a method to evaluate geometric and dosimetric uncertainties using radiochromic films.

    PubMed

    Coscia, Gianluca; Vaccara, Elena; Corvisiero, Roberta; Cavazzani, Paolo; Ruggieri, Filippo Grillo; Taccini, Gianni

    2009-07-01

    In the authors' hospital, stereotactic radiotherapy treatments are performed with a Varian Clinac 600C equipped with a BrainLAB m3 micro-multileaf-collimator generally using the dynamic conformal arc technique. Patient immobilization during the treatment is achieved with a fixation mask supplied by BrainLAB, made with two reinforced thermoplastic sheets fitting the patient's head. With this work the authors propose a method to evaluate treatment geometric accuracy and, consequently, to determine the amount of the margin to keep in the CTV-PTV expansion during the treatment planning. The reproducibility of the isocenter position was tested by simulating a complete treatment on the anthropomorphic phantom Alderson Rando, inserting in between two phantom slices a high sensitivity Gafchromic EBT film, properly prepared and calibrated, and repeating several treatment sessions, each time removing the fixing mask and replacing the film inside the phantom. The comparison between the dose distributions measured on films and computed by TPS, after a precise image registration procedure performed by a commercial piece of software (FILMQA, 3cognition LLC (Division of ISP), Wayne, NJ), allowed the authors to measure the repositioning errors, obtaining about 0.5 mm in case of central spherical PTV and about 1.5 mm in case of peripheral irregular PTV. Moreover, an evaluation of the errors in the registration procedure was performed, giving negligible values with respect to the quantities to be measured. The above intrinsic two-dimensional estimate of treatment accuracy has to be increased for the error in the third dimension, but the 2 mm margin the authors generally use for the CTV-PTV expansion seems adequate anyway. Using the same EBT films, a dosimetric verification of the treatment planning system was done. Measured dose values are larger or smaller than the nominal ones depending on geometric irradiation conditions, but, in the authors' experimental conditions, always

  18. Fractionated stereotactic radiotherapy: A method to evaluate geometric and dosimetric uncertainties using radiochromic films

    SciTech Connect

    Coscia, Gianluca; Vaccara, Elena; Corvisiero, Roberta; Cavazzani, Paolo; Ruggieri, Filippo Grillo; Taccini, Gianni

    2009-07-15

    In the authors' hospital, stereotactic radiotherapy treatments are performed with a Varian Clinac 600C equipped with a BrainLAB m3 micro-multileaf-collimator generally using the dynamic conformal arc technique. Patient immobilization during the treatment is achieved with a fixation mask supplied by BrainLAB, made with two reinforced thermoplastic sheets fitting the patient's head. With this work the authors propose a method to evaluate treatment geometric accuracy and, consequently, to determine the amount of the margin to keep in the CTV-PTV expansion during the treatment planning. The reproducibility of the isocenter position was tested by simulating a complete treatment on the anthropomorphic phantom Alderson Rando, inserting in between two phantom slices a high sensitivity Gafchromic EBT film, properly prepared and calibrated, and repeating several treatment sessions, each time removing the fixing mask and replacing the film inside the phantom. The comparison between the dose distributions measured on films and computed by TPS, after a precise image registration procedure performed by a commercial piece of software (FILMQA, 3cognition LLC (Division of ISP), Wayne, NJ), allowed the authors to measure the repositioning errors, obtaining about 0.5 mm in case of central spherical PTV and about 1.5 mm in case of peripheral irregular PTV. Moreover, an evaluation of the errors in the registration procedure was performed, giving negligible values with respect to the quantities to be measured. The above intrinsic two-dimensional estimate of treatment accuracy has to be increased for the error in the third dimension, but the 2 mm margin the authors generally use for the CTV-PTV expansion seems adequate anyway. Using the same EBT films, a dosimetric verification of the treatment planning system was done. Measured dose values are larger or smaller than the nominal ones depending on geometric irradiation conditions, but, in the authors' experimental conditions, always

  19. Stereotactic radiosurgery - discharge

    MedlinePlus

    ... pg=stereotactic . Accessed July 22, 2016. Read More Acoustic neuroma Brain tumor - primary - adults Cerebral arteriovenous malformation ... A.M. Editorial team. Related MedlinePlus Health Topics Acoustic Neuroma Arteriovenous Malformations Brain Tumors Childhood Brain Tumors ...

  20. Dose-Volume Response Relationship for Brain Metastases Treated with Frameless Single-Fraction Linear Accelerator-Based Stereotactic Radiosurgery

    PubMed Central

    Pan, Jianmin; Yusuf, Mehran B; Dragun, Anthony; Dunlap, Neal; Guan, Timothy; Boling, Warren; Rai, Shesh; Woo, Shiao

    2016-01-01

    Background: Our aim was to identify a dose-volume response relationship for brain metastases treated with frameless stereotactic radiosurgery (SRS). Methods: We reviewed patients who underwent frameless single-fraction linear accelerator SRS for brain metastases between 2007 and 2013 from an institutional database. Proportional hazards modeling was used to identify predictors of outcome. A ratio of maximum lesion dose per mm-diameter (Gy/mm) was constructed to establish a dose-volume relationship. Results: There were 316 metastases evaluated in 121 patients (2 - 33 mm in the largest diameter). The median peripheral dose was 18.0 Gy (range: 10.0 – 24.0 Gy). Local control was 84.8% for all lesions and was affected by location, peripheral dose, maximum dose, and lesion size (p values < 0.050). A dose-volume response relationship was constructed using the maximum dose and lesion size. A unit increase in Gy/mm was associated with decreased local failure (p = 0.005). Local control of 80%, 85%, and 90% corresponded to maximum doses per millimeter of 1.67 Gy/mm, 2.86 Gy/mm, and 4.4 Gy/mm, respectively. Toxicity was uncommon and only 1.0% of lesions developed radionecrosis requiring surgery. Conclusions: For brain metastases less than 3 cm, a dose-volume response relationship exists between maximum radiosurgical dose and lesion size, which is predictive of local control. PMID:27284495

  1. Outcomes and Toxicity for Hypofractionated and Single-Fraction Image-Guided Stereotactic Radiosurgery for Sarcomas Metastasizing to the Spine

    SciTech Connect

    Folkert, Michael R.; Bilsky, Mark H.; Tom, Ashlyn K.; Oh, Jung Hun; Alektiar, Kaled M.; Laufer, Ilya; Tap, William D.; Yamada, Yoshiya

    2014-04-01

    Purpose: Conventional radiation treatment (20-40 Gy in 5-20 fractions, 2-5 Gy per fraction) for sarcoma metastatic to the spine provides subtherapeutic doses, resulting in poor durable local control (LC) (50%-77% at 1 year). Hypofractionated (HF) and/or single-fraction (SF) image-guided stereotactic radiosurgery (IG-SRS) may provide a more effective means of managing these lesions. Methods and Materials: Patients with pathologically proven high-grade sarcoma metastatic to the spine treated with HF and SF IG-SRS were included. LC and overall survival (OS) were analyzed by the use of Kaplan-Meier statistics. Univariate and multivariate analyses were performed by the use of Cox regression with competing-risks analysis; all confidence intervals are 95%. Toxicities were assessed according to Common Terminology Criteria for Adverse Events, version 4.0. Results: From May 2005 to November 11, 2012, 88 patients with 120 discrete metastases received HF (3-6 fractions; median dose, 28.5 Gy; n=52, 43.3%) or SF IG-SRS (median dose, 24 Gy; n=68, 56.7%). The median follow-up time was 12.3 months. At 12 months, LC was 87.9% (confidence interval [CI], 81.3%-94.5%), OS was 60.6% (CI, 49.6%-71.6%), and median survival was 16.9 months. SF IG-SRS demonstrated superior LC to HF IG-SRS (12-month LC of 90.8% [CI, 83%-98.6%] vs 84.1% [CI, 72.9%-95.3%] P=.007) and retained significance on multivariate analysis (P=.030, hazard ratio 0.345; CI, 0.132-0.901]. Treatment was well tolerated, with 1% acute grade 3 toxicity, 4.5% chronic grade 3 toxicity, and no grade >3 toxicities. Conclusions: In the largest series of metastatic sarcoma to the spine to date, IG-SRS provides excellent LC in the setting of an aggressive disease with low radiation sensitivity and poor prognosis. Single-fraction IG-SRS is associated with the highest rates of LC with minimal toxicity.

  2. Single-Fraction Stereotactic Body Radiation Therapy and Sequential Gemcitabine for the Treatment of Locally Advanced Pancreatic Cancer

    SciTech Connect

    Schellenberg, Devin; Kim, Jeff; Christman-Skieller, Claudia; Chun, Carlene L.; Columbo, Laurie Ann; Ford, James M.; Fisher, George A.; Kunz, Pamela L.; Van Dam, Jacques; Quon, Andrew; Desser, Terry S.; Norton, Jeffrey; Hsu, Annie; Maxim, Peter G.; Xing, Lei; Goodman, Karyn A.; Chang, Daniel T.; Koong, Albert C.

    2011-09-01

    Purpose: This Phase II trial evaluated the toxicity, local control, and overall survival in patients treated with sequential gemcitabine and linear accelerator-based single-fraction stereotactic body radiotherapy (SBRT). Methods and Materials: Twenty patients with locally advanced, nonmetastatic pancreatic adenocarcinoma were enrolled on this prospective single-institution, institutional review board-approved study. Gemcitabine was administered on Days 1, 8, and 15, and SBRT on Day 29. Gemcitabine was restarted on Day 43 and continued for 3-5 cycles. SBRT of 25 Gy in a single fraction was delivered to the internal target volume with a 2- 3-mm margin using a nine-field intensity-modulated radiotherapy technique. Respiratory gating was used to account for breathing motion. Follow-up evaluations occurred at 4-6 weeks, 10-12 weeks, and every 3 months after SBRT. Results: All patients completed SBRT and a median of five cycles of chemotherapy. Follow-up for the 2 remaining alive patients was 25.1 and 36.4 months. No acute Grade 3 or greater nonhematologic toxicity was observed. Late Grade 3 or greater toxicities occurred in 1 patient (5%) and consisted of a duodenal perforation (G4). Three patients (15%) developed ulcers (G2) that were medically managed. Overall, median survival was 11.8 months, with 1-year survival of 50% and 2-year survival of 20%. Using serial computed tomography, the freedom from local progression was 94% at 1 year. Conclusion: Linear accelerator-delivered SBRT with sequential gemcitabine resulted in excellent local control of locally advanced pancreatic cancer. Future studies will address strategies for reducing long-term duodenal toxicity associated with SBRT.

  3. Long-Term Outcomes of Fractionated Stereotactic Radiation Therapy for Pituitary Adenomas at the BC Cancer Agency

    SciTech Connect

    Kim, Julian O.; Ma, Roy; Akagami, Ryojo; McKenzie, Michael; Johnson, Michelle; Gete, Ermias; Nichol, Alan

    2013-11-01

    Purpose: To assess the long-term disease control and toxicity outcomes of fractionated stereotactic radiation therapy (FSRT) in patients with pituitary adenomas treated at the BC Cancer Agency. Methods and Materials: To ensure a minimum of 5 years of clinical follow-up, this study identified a cohort of 76 patients treated consecutively with FSRT between 1998 and 2007 for pituitary adenomas: 71% (54/76) had nonfunctioning and 29% (22/76) had functioning adenomas (15 adrenocorticotrophic hormone-secreting, 5 growth hormone-secreting, and 2 prolactin-secreting). Surgery was used before FSRT in 96% (73/76) of patients. A median isocenter dose of 50.4 Gy was delivered in 28 fractions, with 100% of the planning target volume covered by the 90% isodose. Patients were followed up clinically by endocrinologists, ophthalmologists, and radiation oncologists. Serial magnetic resonance imaging was used to assess tumor response. Results: With a median follow-up time of 6.8 years (range, 0.6 - 13.1 years), the 7-year progression-free survival was 97.1% and disease-specific survival was 100%. Of the 2 patients with tumor progression, both had disease control after salvage surgery. Of the 22 patients with functioning adenomas, 50% (11/22) had complete and 9% (2/22) had partial responses after FSRT. Of the patients with normal pituitary function at baseline, 48% (14/29) experienced 1 or more hormone deficiencies after FSRT. Although 79% (60/76) of optic chiasms were at least partially within the planning target volumes, no patient experienced radiation-induced optic neuropathy. No patient experienced radionecrosis. No secondary malignancy occurred during follow-up. Conclusion: In this study of long-term follow-up of patients treated for pituitary adenomas, FSRT was safe and effective.

  4. Fractionated stereotactic radiotherapy plus bevacizumab after response to bevacizumab plus irinotecan as a rescue treatment for high-grade gliomas

    PubMed Central

    Conde-Moreno, Antonio José; García-Gómez, Raquel; Albert-Antequera, María; Almendros-Blanco, Piedad; De Las Peñas-Bataller, Ramón; González-Vidal, Verónica; López-Torrecilla, José Luis; Ferrer-Albiach, Carlos

    2015-01-01

    Aim To evaluate the possibility of implementing a new scheme of rescue treatment after relapse or progression of high-grade glioma (HGG) treated at the first-line with bevacizumab and irinotecan (BVZ+CPT11), evaluating the response and toxicity of associating BVZ and fractionated stereotactic radiotherapy (BVZ+FSRT). Materials and methods We retrospectively analysed data from 59 patients with relapse of HGG. Nine patients with HGG relapse after treatment using the Stupp protocol that were treated with BVZ+CPT11 for progression between July 2007 and August 2012, after which the response was assessed according to the Revised Assessment in Neuro-Oncology (RANO) criteria. BVZ was administered at a dose of 10 mg/kg and FSRT up to a prescribed dose of 30 Gy, 500 cGy per fraction, three days a week. The median follow-up was 38 months. Results The treatment was well-tolerated by all patients. The response after nuclear magnetic resonance imaging (MRI) at 3–6 months was progression in two patients, stable disease in four, and three patients had a partial response. The median overall survival (OS) from diagnosis until death or the last control was 36.8 months. The median progression-free survival (PFS) was 10.8 months. The results from tumour sub-group analysis indicated that the PFS was not statistically significant although it seemed that it was higher in grade-III. The OS was higher in grade-III gliomas. Conclusions The combination of BVZ+FSRT as a second-line HGG relapse rescue treatment is well-tolerated and seems to offer promising results. We believe that multi-centre prospective studies are needed to determine the long-term efficacy and toxicity of this therapeutic approach. PMID:25949228

  5. A planning study investigating dual-gated volumetric arc stereotactic treatment of primary renal cell carcinoma

    SciTech Connect

    Devereux, Thomas; Pham, Daniel; Kron, Tomas; Foroudi, Farshad; Supple, Jeremy; Siva, Shankar

    2015-04-01

    This is a planning study investigating the dosimetric advantages of gated volumetric-modulated arc therapy (VMAT) to the end-exhale and end-inhale breathing phases for patients undergoing stereotactic treatment of primary renal cell carcinoma. VMAT plans were developed from the end-inhale (VMATinh) and the end-exhale (VMATexh) phases of the breathing cycle as well as a VMAT plan and 3-dimensional conformal radiation therapy plan based on an internal target volume (ITV) (VMATitv). An additional VMAT plan was created by giving the respective gated VMAT plan a 50% weighting and summing the inhale and exhale plans together to create a summed gated plan. Dose to organs at risk (OARs) as well as comparison of intermediate and low-dose conformity was evaluated. There was no difference in the volume of healthy tissue receiving the prescribed dose for the planned target volume (PTV) (CI100%) for all the VMAT plans; however, the mean volume of healthy tissue receiving 50% of the prescribed dose for the PTV (CI50%) values were 4.7 (± 0.2), 4.6 (± 0.2), and 4.7 (± 0.6) for the VMATitv, VMATinh, and VMATexh plans, respectively. The VMAT plans based on the exhale and inhale breathing phases showed a 4.8% and 2.4% reduction in dose to 30 cm{sup 3} of the small bowel, respectively, compared with that of the ITV-based VMAT plan. The summed gated VMAT plans showed a 6.2% reduction in dose to 30 cm{sup 3} of the small bowel compared with that of the VMAT plans based on the ITV. Additionally, when compared with the inhale and the exhale VMAT plans, a 4% and 1.5%, respectively, reduction was observed. Gating VMAT was able to reduce the amount of prescribed, intermediate, and integral dose to healthy tissue when compared with VMAT plans based on an ITV. When summing the inhale and exhale plans together, dose to healthy tissue and OARs was optimized. However, gating VMAT plans would take longer to treat and is a factor that needs to be considered.

  6. Three independent one-dimensional margins for single-fraction frameless stereotactic radiosurgery brain cases using CBCT

    SciTech Connect

    Zhang, Qinghui; Chan, Maria F.; Burman, Chandra; Song, Yulin; Zhang, Mutian

    2013-12-15

    Purpose: Setting a proper margin is crucial for not only delivering the required radiation dose to a target volume, but also reducing the unnecessary radiation to the adjacent organs at risk. This study investigated the independent one-dimensional symmetric and asymmetric margins between the clinical target volume (CTV) and the planning target volume (PTV) for linac-based single-fraction frameless stereotactic radiosurgery (SRS).Methods: The authors assumed a Dirac delta function for the systematic error of a specific machine and a Gaussian function for the residual setup errors. Margin formulas were then derived in details to arrive at a suitable CTV-to-PTV margin for single-fraction frameless SRS. Such a margin ensured that the CTV would receive the prescribed dose in 95% of the patients. To validate our margin formalism, the authors retrospectively analyzed nine patients who were previously treated with noncoplanar conformal beams. Cone-beam computed tomography (CBCT) was used in the patient setup. The isocenter shifts between the CBCT and linac were measured for a Varian Trilogy linear accelerator for three months. For each plan, the authors shifted the isocenter of the plan in each direction by ±3 mm simultaneously to simulate the worst setup scenario. Subsequently, the asymptotic behavior of the CTV V{sub 80%} for each patient was studied as the setup error approached the CTV-PTV margin.Results: The authors found that the proper margin for single-fraction frameless SRS cases with brain cancer was about 3 mm for the machine investigated in this study. The isocenter shifts between the CBCT and the linac remained almost constant over a period of three months for this specific machine. This confirmed our assumption that the machine systematic error distribution could be approximated as a delta function. This definition is especially relevant to a single-fraction treatment. The prescribed dose coverage for all the patients investigated was 96.1%± 5.5% with an

  7. Hippocampal Dosimetry Predicts Neurocognitive Function Impairment After Fractionated Stereotactic Radiotherapy for Benign or Low-Grade Adult Brain Tumors

    SciTech Connect

    Gondi, Vinai; Hermann, Bruce P.; Mehta, Minesh P.; Tome, Wolfgang A.

    2012-07-15

    Purpose: To prospectively evaluate the association between hippocampal dose and long-term neurocognitive function (NCF) impairment for benign or low-grade adult brain tumors treated with fractionated stereotactic radiotherapy (FSRT). Methods and Materials: Adult patients with benign or low-grade adult brain tumors were treated with FSRT per institutional practice. No attempt was made to spare the hippocampus. NCF testing was conducted at baseline and 18 months follow-up, on a prospective clinical trial. Regression-based standardized z scores were calculated by using similar healthy control individuals evaluated at the same test-retest interval. NCF impairment was defined as a z score {<=}-1.5. After delineation of the bilateral hippocampi according to the Radiation Therapy Oncology Group contouring atlas, dose-volume histograms were generated for the left and right hippocampi and for the composite pair. Biologically equivalent doses in 2-Gy fractions (EQD{sub 2}) assuming an {alpha}/{beta} ratio of 2 Gy were computed. Fisher's exact test and binary logistic regression were used for univariate and multivariate analyses, respectively. Dose-response data were fit to a nonlinear model. Results: Of 29 patients enrolled in this trial, 18 completed both baseline and 18-month NCF testing. An EQD{sub 2} to 40% of the bilateral hippocampi >7.3 Gy was associated with impairment in Wechsler Memory Scale-III Word List (WMS-WL) delayed recall (odds ratio [OR] 19.3; p = 0.043). The association between WMS-WL delayed recall and EQD{sub 2} to 100% of the bilateral hippocampi >0.0 Gy trended to significance (OR 14.8; p = 0.068). Conclusion: EQD{sub 2} to 40% of the bilateral hippocampi greater than 7.3 Gy is associated with long-term impairment in list-learning delayed recall after FSRT for benign or low-grade adult brain tumors. Given that modern intensity-modulated radiotherapy techniques can reduce the dose to the bilateral hippocampi below this dosimetric threshold, patients

  8. Hippocampal Dosimetry Predicts Neurocognitive Function Impairment After Fractionated Stereotactic Radiotherapy for Benign or Low-Grade Adult Brain Tumors

    SciTech Connect

    Gondi, Vinai; Hermann, Bruce P.; Mehta, Minesh P.; Tome, Wolfgang A.

    2013-02-01

    Purpose: To prospectively evaluate the association between hippocampal dose and long-term neurocognitive function (NCF) impairment for benign or low-grade adult brain tumors treated with fractionated stereotactic radiotherapy (FSRT). Methods and Materials: Adult patients with benign or low-grade adult brain tumors were treated with FSRT per institutional practice. No attempt was made to spare the hippocampus. NCF testing was conducted at baseline and 18 months follow-up, on a prospective clinical trial. Regression-based standardized z scores were calculated by using similar healthy control individuals evaluated at the same test-retest interval. NCF impairment was defined as a z score {<=}-1.5. After delineation of the bilateral hippocampi according to the Radiation Therapy Oncology Group contouring atlas, dose-volume histograms were generated for the left and right hippocampi and for the composite pair. Biologically equivalent doses in 2-Gy fractions (EQD{sub 2}) assuming an {alpha}/{beta} ratio of 2 Gy were computed. Fisher's exact test and binary logistic regression were used for univariate and multivariate analyses, respectively. Dose-response data were fit to a nonlinear model. Results: Of 29 patients enrolled in this trial, 18 completed both baseline and 18-month NCF testing. An EQD{sub 2} to 40% of the bilateral hippocampi >7.3 Gy was associated with impairment in Wechsler Memory Scale-III Word List (WMS-WL) delayed recall (odds ratio [OR] 19.3; p = 0.043). The association between WMS-WL delayed recall and EQD{sub 2} to 100% of the bilateral hippocampi >0.0 Gy trended to significance (OR 14.8; p = 0.068). Conclusion: EQD{sub 2} to 40% of the bilateral hippocampi greater than 7.3 Gy is associated with long-term impairment in list-learning delayed recall after FSRT for benign or low-grade adult brain tumors. Given that modern intensity-modulated radiotherapy techniques can reduce the dose to the bilateral hippocampi below this dosimetric threshold, patients

  9. Stereotactic Body Radiotherapy as Primary Therapy for Head and Neck Cancer in the Elderly or Patients with Poor Performance

    PubMed Central

    Amini, Arya; McDermott, Jessica D.; Gan, Gregory; Bhatia, Shilpa; Sumner, Whitney; Fisher, Christine M.; Jimeno, Antonio; Bowles, Daniel W.; Raben, David; Karam, Sana D.

    2014-01-01

    Objective: Stereotactic body radiotherapy (SBRT) is increasingly used to treat a variety of tumors, including head and neck squamous cell carcinoma (HNSCC) in the recurrent setting. While there are published data for re-irradiation using SBRT for HNSCC, there are limited data supporting its use as upfront treatment for locally advanced disease. Study Design/Methods: Here, we describe three patients who received SBRT as the primary treatment for their HNSCC along with a review of the current literature and discussion of future pathways. Results: The three cases discussed tolerated treatment well with manageable acute toxicities and had either a clinical or radiographic complete response to therapy. Conclusion: Head and neck squamous cell carcinoma presents a unique challenge in the elderly, where medical comorbidities make it difficult to tolerate conventional radiation, often given with a systemic sensitizer. For these individuals, providing a shortened course using SBRT may offer an effective alternative. PMID:25340041

  10. Primary Student Teachers' Perspectives of the Teaching of Fractions

    ERIC Educational Resources Information Center

    Savas Basturk

    2016-01-01

    The aim of this study was to investigate primary student teachers' perspectives of the teaching of fractions, i.e. their PCK of fractions. The research design used for the study was a descriptive survey method. As data collection instrument, we conducted a questionnaire composing of 14 open and closed-ended questions. The questionnaire was…

  11. Hypofractionated stereotactic body radiotherapy for primary and metastatic liver tumors using the novalis image-guided system: preliminary results regarding efficacy and toxicity.

    PubMed

    Iwata, Hiromitsu; Shibamoto, Yuta; Hashizume, Chisa; Mori, Yoshimasa; Kobayashi, Tatsuya; Hayashi, Naoki; Kosaki, Katsura; Ishikawa, Tetsuya; Kuzuya, Teiji; Utsunomiya, Setsuo

    2010-12-01

    www.tcrt.org The purpose of this study was to evaluate the efficacy and toxicity of stereotactic body radiotherapy (SBRT) for primary and metastatic liver tumors using the Novalis image-guided radiotherapy system. After preliminarily treating liver tumors using the Novalis system from July 2006, we started a protocol-based study in February 2008. Eighteen patients (6 with primary hepatocellular carcinoma and 12 with metastatic liver tumor) were treated with 55 or 50 Gy, depending upon their planned dose distribution and liver function, delivered in 10 fractions over 2 weeks. Four non-coplanar and three coplanar static beams were used. Patient age ranged from 54 to 84 years (median: 72 years). The Child-Pugh classification was Grade A in 17 patients and Grade B in 1. Tumor diameter ranged from 12 to 35 mm (median: 23 mm). Toxicities were evaluated according to the Common Terminology Criteria of Adverse Events version 4.0, and radiation-induced liver disease (RILD) was defined by Lawrence's criterion. The median follow-up period was 14.5 months. For all patients, the 1-year overall survival and local control rates were 94% and 86%, respectively. A Grade 1 liver enzyme change was observed in 5 patients, but no RILD or chronic liver dysfunction was observed. SBRT using the Novalis image-guided system is safe and effective for treating primary and metastatic liver tumors. Further investigation of SBRT for liver tumors is warranted. In view of the acceptable toxicity observed with this protocol, we have moved to a new protocol to shorten the overall treatment time and escalate the dose.

  12. SU-E-T-563: Multi-Fraction Stereotactic Radiosurgery with Extend System of Gamma Knife: Treatment Verification Using Indigenously Designed Patient Simulating Multipurpose Phantom

    SciTech Connect

    Bisht, R; Kale, S; Gopishankar, N; Rath, G; Julka, P; Agarwal, D; Singh, M; Garg, A; Kumar, P; Thulkar, S; Sharma, B

    2015-06-15

    Purpose: Aim of the study is to evaluate mechanical and radiological accuracy of multi-fraction regimen and validate Gamma knife based fractionation using newly developed patient simulating multipurpose phantom. Methods: A patient simulating phantom was designed to verify fractionated treatments with extend system (ES) of Gamma Knife however it could be used to validate other radiotherapy procedures as well. The phantom has options to insert various density material plugs and mini CT/MR distortion phantoms to analyze the quality of stereotactic imaging. An additional thorax part designed to predict surface doses at various organ sites. The phantom was positioned using vacuum head cushion and patient control unit for imaging and treatment. The repositioning check tool (RCT) was used to predict phantom positioning under ES assembly. The phantom with special inserts for film in axial, coronal and sagittal plane were scanned with X-Ray CT and the acquired images were transferred to treatment planning system (LGP 10.1). The focal precession test was performed with 4mm collimator and an experimental plan of four 16mm collimator shots was prepared for treatment verification of multi-fraction regimen. The prescription dose of 5Gy per fraction was delivered in four fractions. Each fraction was analyzed using EBT3 films scanned with EPSON 10000XL Scanner. Results: The measurement of 38 RCT points showed an overall positional accuracy of 0.28mm. The mean deviation of 0.28% and 0.31 % were calculated as CT and MR image distortion respectively. The radiological focus accuracy test showed its deviation from mechanical center point of 0.22mm. The profile measurement showed close agreement between TPS planned and film measured dose. At tolerance criteria of 1%/1mm gamma index analysis showed a pass rate of > 95%. Conclusion: Our results show that the newly developed multipurpose patient simulating phantom is highly suitable for the verification of fractionated stereotactic

  13. Effect of different breathing patterns in the same patient on stereotactic ablative body radiotherapy dosimetry for primary renal cell carcinoma: A case study

    SciTech Connect

    Pham, Daniel; Kron, Tomas; Foroudi, Farshad; Siva, Shankar

    2013-10-01

    Stereotactic ablative body radiotherapy (SABR) for primary renal cell carcinoma (RCC) targets requires motion management strategies to verify dose delivery. This case study highlights the effect of a change in patient breathing amplitude on the dosimetry to organs at risk and target structures. A 73-year-old male patient was planned for receiving 26 Gy of radiation in 1 fraction of SABR for a left primary RCC. The patient was simulated with four-dimensional computed tomography (4DCT) and the tumor internal target volume (ITV) was delineated using the 4DCT maximum intensity projection. However, the initially planned treatment was abandoned at the radiation oncologist's discretion after pretreatment cone-beam CT (CBCT) motion verification identified a greater than 50% reduction in superior to inferior diaphragm motion as compared with the planning 4DCT. This patient was resimulated with respiratory coaching instructions. To assess the effect of the change in breathing on the dosimetry to the target, each plan was recalculated on the data set representing the change in breathing condition. A change from smaller to larger breathing showed a 46% loss in planning target volume (PTV) coverage, whereas a change from larger breathing to smaller breathing resulted in an 8% decrease in PTV coverage. ITV coverage was similarly reduced by 8% in both scenarios. This case study highlights the importance of tools to verify breathing motion prior to treatment delivery. 4D image guided radiation therapy verification strategies should focus on not only verifying ITV margin coverage but also the effect on the surrounding organs at risk.

  14. Effect of different breathing patterns in the same patient on stereotactic ablative body radiotherapy dosimetry for primary renal cell carcinoma: a case study.

    PubMed

    Pham, Daniel; Kron, Tomas; Foroudi, Farshad; Siva, Shankar

    2013-01-01

    Stereotactic ablative body radiotherapy (SABR) for primary renal cell carcinoma (RCC) targets requires motion management strategies to verify dose delivery. This case study highlights the effect of a change in patient breathing amplitude on the dosimetry to organs at risk and target structures. A 73-year-old male patient was planned for receiving 26Gy of radiation in 1 fraction of SABR for a left primary RCC. The patient was simulated with four-dimensional computed tomography (4DCT) and the tumor internal target volume (ITV) was delineated using the 4DCT maximum intensity projection. However, the initially planned treatment was abandoned at the radiation oncologist's discretion after pretreatment cone-beam CT (CBCT) motion verification identified a greater than 50% reduction in superior to inferior diaphragm motion as compared with the planning 4DCT. This patient was resimulated with respiratory coaching instructions. To assess the effect of the change in breathing on the dosimetry to the target, each plan was recalculated on the data set representing the change in breathing condition. A change from smaller to larger breathing showed a 46% loss in planning target volume (PTV) coverage, whereas a change from larger breathing to smaller breathing resulted in an 8% decrease in PTV coverage. ITV coverage was similarly reduced by 8% in both scenarios. This case study highlights the importance of tools to verify breathing motion prior to treatment delivery. 4D image guided radiation therapy verification strategies should focus on not only verifying ITV margin coverage but also the effect on the surrounding organs at risk.

  15. Stereotactic Radiotherapy of Primary Lung Cancer and Other Targets: Results of Consultant Meeting of the International Atomic Energy Agency

    SciTech Connect

    Nagata, Yasushi; Wulf, Joern; Lax, Ingmar; Timmerman, Robert; Zimmermann, Frank; Stojkovski, Igor; Jeremic, Branislav

    2011-03-01

    To evaluate the current status of stereotactic body radiotherapy (SBRT) and identify both advantages and disadvantages of its use in developing countries, a meeting composed of consultants of the International Atomic Energy Agency was held in Vienna in November 2006. Owing to continuous developments in the field, the meeting was extended by subsequent discussions and correspondence (2007-2010), which led to the summary presented here. The advantages and disadvantages of SBRT expected to be encountered in developing countries were identified. The definitions, typical treatment courses, and clinical results were presented. Thereafter, minimal methodology/technology requirements for SBRT were evaluated. Finally, characteristics of SBRT for developing countries were recommended. Patients for SBRT should be carefully selected, because single high-dose radiotherapy may cause serious complications in some serial organs at risk. Clinical experiences have been reported in some populations of lung cancer, lung oligometastases, liver cancer, pancreas cancer, and kidney cancer. Despite the disadvantages expected to be experienced in developing countries, SBRT using fewer fractions may be useful in selected patients with various extracranial cancers with favorable outcome and low toxicity.

  16. On the use of volumetric-modulated arc therapy for single-fraction thoracic vertebral metastases stereotactic body radiosurgery.

    PubMed

    Pokhrel, Damodar; Sood, Sumit; McClinton, Christopher; Shen, Xinglei; Badkul, Rajeev; Jiang, Hongyu; Mallory, Matthew; Mitchell, Mellissa; Wang, Fen; Lominska, Christopher

    2017-01-01

    To retrospectively evaluate quality, efficiency, and delivery accuracy of volumetric-modulated arc therapy (VMAT) plans for single-fraction treatment of thoracic vertebral metastases using image-guided stereotactic body radiosurgery (SBRS) after RTOG 0631 dosimetric compliance criteria. After obtaining credentialing for MD Anderson spine phantom irradiation validation, 10 previously treated patients with thoracic vertebral metastases with noncoplanar hybrid arcs using 1 to 2 3D-conformal partial arcs plus 7 to 9 intensity-modulated radiation therapy beams were retrospectively re-optimized with VMAT using 3 full coplanar arcs. Tumors were located between T2 and T12. Contrast-enhanced T1/T2-weighted magnetic resonance images were coregistered with planning computed tomography and planning target volumes (PTV) were between 14.4 and 230.1cc (median = 38.0cc). Prescription dose was 16Gy in 1 fraction with 6MV beams at Novalis-TX linear accelerator consisting of micro multileaf collimators. Each plan was assessed for target coverage using conformality index, the conformation number, the ratio of the volume receiving 50% of the prescription dose over PTV, R50%, homogeneity index (HI), and PTV_1600 coverage per RTOG 0631 requirements. Organs-at-risk doses were evaluated for maximum doses to spinal cord (D0.03cc, D0.35cc), partial spinal cord (D10%), esophagus (D0.03cc and D5cc), heart (D0.03cc and D15cc), and lung (V5, V10, and maximum dose to 1000cc of lung). Dose delivery efficiency and accuracy of each VMAT-SBRS plan were assessed using quality assurance (QA) plan on MapCHECK device. Total beam-on time was recorded during QA procedure, and a clinical gamma index (2%/2mm and 3%/3mm) was used to compare agreement between planned and measured doses. All 10 VMAT-SBRS plans met RTOG 0631 dosimetric requirements for PTV coverage. The plans demonstrated highly conformal and homogenous coverage of the vertebral PTV with mean HI, conformality index, conformation number, and R50

  17. The impact of abdominal compression on outcome in patients treated with stereotactic body radiotherapy for primary lung cancer

    PubMed Central

    Mampuya, Wambaka Ange; Matsuo, Yukinori; Ueki, Nami; Nakamura, Mitsuhiro; Mukumoto, Nobutaka; Nakamura, Akira; Iizuka, Yusuke; Kishi, Takahiro; Mizowaki, Takashi; Hiraoka, Masahiro

    2014-01-01

    The aim of this study was to evaluate the impact of abdominal compression (AC) on outcome in patients treated with stereotactic body radiotherapy (SBRT) for primary lung cancer. We retrospectively reviewed data for 47 patients with histologically proven non-small cell lung cancer and lung tumour motion ≥8 mm treated with SBRT. Setup error was corrected based on bony structure. The differences in overall survival (OS), local control (LC) and disease-free survival (DFS) were evaluated to compare patients treated with AC (n = 22) and without AC (n = 25). The median follow-up was 42.6 months (range, 1.4–94.6 months). The differences in the 3-year OS, LC and DFS rate between the two groups were not statistically significant (P = 0.909, 0.209 and 0.639, respectively). However, the largest difference was observed in the LC rate, which was 82.5% (95% CI, 54.9–94.0%) for patients treated without AC and 65.4% (95% CI, 40.2–82.0%) for those treated with AC. After stratifying the patients into prognostic groups based on sex and T-stage, the LC difference increased in the group with an unfavourable prognosis. The present study suggests that AC might be associated with a worse LC rate after SBRT using a bony-structure-based set-up. PMID:24801474

  18. Stereotactic hypofractionated accurate radiotherapy of the prostate (SHARP), 33.5 Gy in five fractions for localized disease: First clinical trial results

    SciTech Connect

    Madsen, Berit L. . E-mail: ronblm@vmmc.org; Hsi, R. Alex; Pham, Huong T.; Fowler, Jack F.; Esagui, Laura C.; Corman, John

    2007-03-15

    Purpose: To evaluate the feasibility and toxicity of stereotactic hypofractionated accurate radiotherapy (SHARP) for localized prostate cancer. Methods and Materials: A Phase I/II trial of SHARP performed for localized prostate cancer using 33.5 Gy in 5 fractions, calculated to be biologically equivalent to 78 Gy in 2 Gy fractions ({alpha}/{beta} ratio of 1.5 Gy). Noncoplanar conformal fields and daily stereotactic localization of implanted fiducials were used for treatment. Genitourinary (GU) and gastrointestinal (GI) toxicity were evaluated by American Urologic Association (AUA) score and Common Toxicity Criteria (CTC). Prostate-specific antigen (PSA) values and self-reported sexual function were recorded at specified follow-up intervals. Results: The study includes 40 patients. The median follow-up is 41 months (range, 21-60 months). Acute toxicity Grade 1-2 was 48.5% (GU) and 39% (GI); 1 acute Grade 3 GU toxicity. Late Grade 1-2 toxicity was 45% (GU) and 37% (GI). No late Grade 3 or higher toxicity was reported. Twenty-six patients reported potency before therapy; 6 (23%) have developed impotence. Median time to PSA nadir was 18 months with the majority of nadirs less than 1.0 ng/mL. The actuarial 48-month biochemical freedom from relapse is 70% for the American Society for Therapeutic Radiology and Oncology definition and 90% by the alternative nadir + 2 ng/mL failure definition. Conclusions: SHARP for localized prostate cancer is feasible with minimal acute or late toxicity. Dose escalation should be possible.

  19. Salvage Stereotactic Body Radiation Therapy (SBRT) for Local Failure After Primary Lung SBRT

    SciTech Connect

    Hearn, Jason W.D. Videtic, Gregory M.M.; Djemil, Toufik; Stephans, Kevin L.

    2014-10-01

    Purpose: Local failure after definitive stereotactic body radiation therapy (SBRT) for early-stage non-small cell lung cancer (NSCLC) is uncommon. We report the safety and efficacy of SBRT for salvage of local failure after previous SBRT with a biologically effective dose (BED) of ≥100 Gy{sub 10}. Methods and Materials: Using an institutional review board–approved lung SBRT registry, we identified all patients initially treated for early-stage NSCLC between August 2004 and January 2012 who received salvage SBRT for isolated local failure. Failure was defined radiographically and confirmed histologically unless contraindicated. All patients were treated on a Novalis/BrainLAB system using ExacTrac for image guidance, and received a BED of ≥100 Gy{sub 10} for each SBRT course. Tumor motion control involved a Bodyfix vacuum system for immobilization along with abdominal compression. Results: Of 436 patients treated from August 2004 through January 2012, we identified 22 patients with isolated local failure, 10 of whom received SBRT for salvage. The median length of follow-up was 13.8 months from salvage SBRT (range 5.3-43.5 months). Median tumor size was 3.4 cm (range 1.7-4.8 cm). Two of the 10 lesions were “central” by proximity to the mediastinum, but were outside the zone of the proximal bronchial tree. Since completing salvage, 3 patients are alive and without evidence of disease. A fourth patient died of medical comorbidities without recurrence 13.0 months after salvage SBRT. Two patients developed distant disease only. Four patients had local failure. Toxicity included grade 1-2 fatigue (3 patients) and grade 1-2 chest wall pain (5 patients). There was no grade 3-5 toxicity. Conclusions: Repeat SBRT with a BED of ≥100 Gy{sub 10} after local failure in patients with early-stage medically inoperable NSCLC was well tolerated in this series and may represent a viable salvage strategy in select patients with peripheral tumors ≤5 cm.

  20. [Stereotactic radiotherapy for pelvic tumors].

    PubMed

    Mazeron, R; Fumagalli, I

    2014-01-01

    Extracranial stereotactic radiotherapy is booming. The development and spread of dedicated accelerators coupled with efficient methods of repositioning can now allow treatments of mobile lesions with moderate size, with high doses per fraction. Intuitively, except for the prostate, pelvic tumours, often requiring irradiation of regional lymph node drainage, lend little to this type of treatment. However, in some difficult circumstances, such as boost or re-radiation, stereotactic irradiation condition is promising and clinical experiences have already been reported.

  1. Prostate-specific antigen kinetics after primary stereotactic body radiation therapy using CyberKnife for localized prostate cancer

    PubMed Central

    Park, Yong Hyun; Choi, In Young; Yoon, Sei Chul; Jang, Hong Seok; Moon, Hyong Woo; Hong, Sung-Hoo; Kim, Sae Woong; Hwang, Tae-Kon; Lee, Ji Youl

    2015-01-01

    Purpose To assess prostate-specific antigen (PSA) kinetics and report on the oncologic outcomes for patients with localized prostate cancer treated with stereotactic body radiation therapy (SBRT) using CyberKnife. Methods We extracted the list and data of 39 patients with clinically localized prostate cancer who had undergone primary SBRT using CyberKnife between January 2008 and December 2012 from the Smart Prostate Cancer database system of Seoul St. Mary's Hospital. Changes in PSA over time, PSA velocity, and PSA nadir were evaluated from the completion of SBRT using CyberKnife. Biochemical recurrence (BCR)-free survival after primary SBRT using CyberKnife was determined using Kaplan–Meier analysis. Results The rate of PSA decrease was maximal in the first month (median −3.34 ng/mL/mo), which then fell gradually with median values of −1.51, −0.32, −0.28, −0.20, and −0.03 ng/mL/mo for durations of 3, 6, 9, 12, and 24 months after SBRT using CyberKnife, respectively. The median PSA nadir was 0.31 ng/mL after a median 23 months. Kaplan–Meier analysis calculates an actuarial 5-year BCR-free survival after SBRT using CyberKnife as 80.8%. Conclusions PSA decline occurred rapidly in the first month, and then the rate of PSA decline fell off steadily over time throughout 2 years after treatment. Also, SBRT using CyberKnife leads to long-term favorable BCR-free survival in localized prostate cancer. PMID:26157760

  2. Phase II study to assess the efficacy of conventionally fractionated radiotherapy followed by a stereotactic radiosurgery boost in patients with locally advanced pancreatic cancer

    SciTech Connect

    Koong, Albert C. . E-mail: akoong@stanford.edu; Christofferson, Erin; Le, Quynh-Thu; Goodman, Karyn A.; Ho, Anthony; Kuo, Timothy; Ford, James M.; Fisher, George A.; Greco, Ralph; Norton, Jeffrey; Yang, George P.

    2005-10-01

    Purpose: To determine the efficacy of concurrent 5-fluorouracil (5-FU) and intensity-modulated radiotherapy (IMRT) followed by body stereotactic radiosurgery (SRS) in patients with locally advanced pancreatic cancer. Methods and Materials: In this prospective study, all patients (19) had pathologically confirmed adenocarcinoma and were uniformly staged. Our treatment protocol consisted of 45 Gy IMRT with concurrent 5-FU followed by a 25 Gy SRS boost to the primary tumor. Results: Sixteen patients completed the planned therapy. Two patients experienced Grade 3 toxicity (none had more than Grade 3 toxicity). Fifteen of these 16 patients were free from local progression until death. Median overall survival was 33 weeks. Conclusions: Concurrent IMRT and 5-FU followed by SRS in patients with locally advanced pancreatic cancer results in excellent local control, but does not improve overall survival and is associated with more toxicity than SRS, alone.

  3. Low Incidence of Chest Wall Pain with a Risk-Adapted Lung Stereotactic Body Radiation Therapy Approach Using Three or Five Fractions Based on Chest Wall Dosimetry

    PubMed Central

    Lewis, John H.; Baldini, Elizabeth H.; Chen, Aileen B.; Colson, Yolonda L.; Hacker, Fred L.; Hermann, Gretchen; Kozono, David; Mannarino, Edward; Molodowitch, Christina; Wee, Jon O.; Sher, David J.; Killoran, Joseph H.

    2014-01-01

    Purpose To examine the frequency and potential of dose-volume predictors for chest wall (CW) toxicity (pain and/or rib fracture) for patients receiving lung stereotactic body radiotherapy (SBRT) using treatment planning methods to minimize CW dose and a risk-adapted fractionation scheme. Methods We reviewed data from 72 treatment plans, from 69 lung SBRT patients with at least one year of follow-up or CW toxicity, who were treated at our center between 2010 and 2013. Treatment plans were optimized to reduce CW dose and patients received a risk-adapted fractionation of 18 Gy×3 fractions (54 Gy total) if the CW V30 was less than 30 mL or 10–12 Gy×5 fractions (50–60 Gy total) otherwise. The association between CW toxicity and patient characteristics, treatment parameters and dose metrics, including biologically equivalent dose, were analyzed using logistic regression. Results With a median follow-up of 20 months, 6 (8.3%) patients developed CW pain including three (4.2%) grade 1, two (2.8%) grade 2 and one (1.4%) grade 3. Five (6.9%) patients developed rib fractures, one of which was symptomatic. No significant associations between CW toxicity and patient and dosimetric variables were identified on univariate nor multivariate analysis. Conclusions Optimization of treatment plans to reduce CW dose and a risk-adapted fractionation strategy of three or five fractions based on the CW V30 resulted in a low incidence of CW toxicity. Under these conditions, none of the patient characteristics or dose metrics we examined appeared to be predictive of CW pain. PMID:24728448

  4. Stereotactic Body Radiotherapy for Patients With Unresectable Primary Hepatocellular Carcinoma: Dose-Volumetric Parameters Predicting the Hepatic Complication

    SciTech Connect

    Son, Seok Hyun; Choi, Byung Ock; Ryu, Mi Ryeong; Kang, Young Nam; Jang, Ji Sun; Bae, Si Hyun; Yoon, Seung Kew; Choi, Ihl Bohng; Kang, Ki Mun; Jang, Hong Seok

    2010-11-15

    Purpose: To identify the parameters that predict hepatic toxicity and deterioration of hepatic function. Materials and Methods: A total of 47 patients with small unresectable primary hepatocellular carcinoma received hypofractionated stereotactic body radiotherapy (SBRT) using the CyberKnife. Of those, 36 patients received no other local treatments that could influence hepatic toxicity at least for 3 months after the completion of SBRT. The gross tumor volume (GTV) was 18.3 {+-} 15.9 cm{sup 3} (range, 3.0-81.3 cm{sup 3}), and the total dose administered was 30-39 Gy (median, 36 Gy). To assess the deterioration of hepatic function, we evaluated the presence or absence of the progression of Child-Pugh class (CP class). To identify the parameters of predicting the radiation-induced hepatic toxicity and deterioration of the hepatic function, several clinical and dose-volumetric parameters were evaluated. Results: Of 36 patients, 12 (33%) developed Grade 2 or higher hepatic toxicity and 4 (11%) developed progression of CP class. The multivariate analysis showed that the only significant parameter associated with the progression of CP class was the total liver volume receiving a dose less than 18 Gy (<18 Gy). Conclusions: The progression of CP class after SBRT limits other additional local treatments and also reflects the deterioration of hepatic function. Therefore, it would be important to note that the presence or absence of the progression of CP class is a dose-limiting factor. The total liver volume receiving <18 Gy should be greater than 800 cm{sup 3} to reduce the risk of the deterioration of hepatic function.

  5. Image-guided stereotactic radiotherapy in 4 dogs with intracranial neoplasia.

    PubMed

    Moon, Alaina Burkard; Heller, Heidi Barnes; Forrest, Lisa

    2016-05-01

    The purpose of this study was to describe the use, and side effects, of a novel stereotactic radiotherapy protocol using TomoTherapy(®) in 4 dogs with confirmed or suspected primary extra-axial intracranial neoplasia. Three fractions of 8 Gy were prescribed. Acute side effects were noted in 1 dog; no late effects were noted.

  6. A Phase I Dose-Escalation Study of Fractionated Stereotactic Radiosurgery in Combination With Gefitinib in Patients With Recurrent Malignant Gliomas

    SciTech Connect

    Schwer, Amanda L.; Damek, Denise M.; Kavanagh, Brian D.; Gaspar, Laurie E.; Lillehei, Kevin; Stuhr, Kelly; Chen Changhu

    2008-03-15

    Purpose: To determine the maximum tolerated dose (MTD) of fractionated stereotactic radiosurgery (SRS) with gefitinib in patients with recurrent malignant gliomas. Methods and Materials: A Phase I clinical trial was performed. Eligible patients had pathologically proved recurrent anaplastic astrocytoma or glioblastoma. Patients started gefitinib (250 mg/day) 7 days before SRS and continued for 1 year or until disease progression. SRS was delivered in three fractions over 3 days. The planning target volume (PTV) was the T1-weighted MRI postcontrast enhancing lesion + 2 mm. The first cohort received an SRS dose of 18 Gy, and subsequent cohorts received higher doses up to the maximum dose of 36 Gy. Dose-limiting toxicity (DLT) was any Grade 3 toxicity. The MTD was exceeded if 2 of 6 patients in a cohort experienced DLT. Results: Characteristics of the 15 patients enrolled were: 9 men, 6 women; median age, 47 years (range, 23-65 years); 11 glioblastoma, 4 AA; median prior RT dose, 60 Gy (range, 54-61.2 Gy); median interval since RT, 12 months (range, 3-57 months); median PTV, 41 cc (range, 12-151 cc). Median follow-up time was 7 months (range, 2-28 months). Median time on gefitinib was 5 months (range, 2-12 months). No patient experienced a DLT, and the SRS dose was escalated from 18 to 36 Gy. Grade 1-2 gefitinib-related dermatitis and diarrhea were common (10 and 7 patients, respectively). Conclusion: Fractionated SRS to a dose of 36 Gy in three fractions is well tolerated with gefitinib at daily dose of 250 mg. Further studies of SRS and novel molecular targeted agents are warranted in this challenging clinical setting.

  7. Symptomatic Outcomes in Relation to Tumor Expansion After Fractionated Stereotactic Radiation Therapy for Vestibular Schwannomas: Single-Institutional Long-Term Experience

    SciTech Connect

    Aoyama, Hidefumi; Onodera, Shunsuke; Takeichi, Norihito; Onimaru, Rikiya; Terasaka, Shunsuke; Sawamura, Yutaka; Shirato, Hiroki

    2013-02-01

    Purpose: The effect of transient tumor expansion after conventionally fractionated stereotactic radiation therapy (SRT) on the symptomatic outcomes is not well-known. Methods and Materials: This study enrolled 201 consecutive patients who received SRT for vestibular schwannoma. A conventional fractionation schedule was applied in 194 patients (97%), and 142 (71%) received a total dose of 50 Gy. The median follow-up time was 72 months. Results: The maximum diameter was 9 mm or less in 13 patients, 10-19 mm in 79 patients, 20-29 mm in 87 patients, and 30 mm or greater in 22 patients. At presentation, tumor size of 20 mm or greater was significantly associated with loss of serviceable hearing and trigeminal neuropathy. After SRT, tumor expansion was observed in 42 patients (21%). By tumor size, tumor expansion was observed in 0%, 11.4%, 25.6%, and 50% of patients with tumors of 9 mm or less, 10-19 mm, 20-29 mm, and 30 mm or greater, respectively, in diameter. The tumor expansion was significantly associated with an increased risk of hydrocephalus requiring shunt placement (P=.004), loss of serviceable hearing (P=.0064), and worsening of facial (P<.0001) and trigeminal nerve (P<.0001) functions. Spontaneous tumor shrinkage was observed in 29 of those 42 patients, mostly within 2 years after the expansion, and the majority of the worsened symptoms except for hearing resolved once the tumor had shrunk. As a result, salvage surgical resection for symptomatic relief was required in only 5% of patients. Conclusions: Fractionated SRT could be safely applied even for medium- to large-sized ({>=}20 mm) tumors. However, greater knowledge of the risks and consequences, including transient symptomatic worsening, and the time span of expansion will be required for the follow-up of patients after SRT to avoid unnecessary surgical intervention.

  8. Clinical Outcomes of Biological Effective Dose-Based Fractionated Stereotactic Radiation Therapy for Metastatic Brain Tumors From Non-Small Cell Lung Cancer

    SciTech Connect

    Matsuyama, Tomohiko; Kogo, Kasei; Oya, Natsuo

    2013-03-15

    Purpose: To evaluate the efficacy and toxicity of fractionated stereotactic radiation therapy (FSRT) based on biological effective dose (BED), a novel approach to deliver a fixed BED irrespective of dose fractionation, for brain metastases from non-small cell lung cancer (NSCLC). Methods and Materials: Between March 2005 and March 2009 we treated 299 patients with 1 to 5 lesions from NSCLC (573 total brain metastases) with FSRT using Novalis. The dose fractionation schedules were individually determined to deliver a peripheral BED10 (α/β ratio = 10) of approximately 80 Gy{sub 10}. The median number of fractions was 3 (range, 2-10), the median peripheral BED10 was 83.2 Gy (range, 19.1-89.6 Gy). Patients were followed up with magnetic resonance imaging (MRI) studies performed at 1- to 2-month intervals. The local tumor control rate and overall local progression-free and intracranial relapse-free survival were calculated by the Kaplan-Meier method. Results: Local control rates for all 573 lesions at 6 and 12 months were 96.3% and 94.5%, respectively. By multivariate analysis the tumor diameter was the only factor predictive of the local control rate (P=.001). The median overall survival, local progression-free survival, and intracranial relapse-free survival were 17.1, 14.9, and 4.4 months, respectively. The overall survival, local progression-free survival, and intracranial relapse-free survival rates at 6 and 12 months were 78.5% and 63.3%, 74.3% and 57.8%, and 41.0% and 21.8%, respectively. Six patients (2%) manifested progressive radiation injury to the brain even during therapy with corticosteroids; they underwent hyperbaric oxygen therapy, and follow-up MRI showed improvement. Conclusions: This study showed that BED-based FSRT for brain metastases from NSCLC is a promising strategy that may yield excellent outcomes with acceptable toxicity. Criteria must be established to determine the optimal dose fractionation for individual patients.

  9. On-Board Imaging Validation of Optically Guided Stereotactic Radiosurgery Positioning System for Conventionally Fractionated Radiotherapy for Paranasal Sinus and Skull Base Cancer

    SciTech Connect

    Maxim, Peter G.; Loo, Billy W.; Murphy, James D.; Chu, Karen P.M.; Hsu, Annie; Le, Quynh-Thu

    2011-11-15

    Purpose: To evaluate the positioning accuracy of an optical positioning system for stereotactic radiosurgery in a pilot experience of optically guided, conventionally fractionated, radiotherapy for paranasal sinus and skull base tumors. Methods and Materials: Before each daily radiotherapy session, the positioning of 28 patients was set up using an optical positioning system. After this initial setup, the patients underwent standard on-board imaging that included daily orthogonal kilovoltage images and weekly cone beam computed tomography scans. Daily translational shifts were made after comparing the on-board images with the treatment planning computed tomography scans. These daily translational shifts represented the daily positional error in the optical tracking system and were recorded during the treatment course. For 13 patients treated with smaller fields, a three-degree of freedom (3DOF) head positioner was used for more accurate setup. Results: The mean positional error for the optically guided system in patients with and without the 3DOF head positioner was 1.4 {+-} 1.1 mm and 3.9 {+-} 1.6 mm, respectively (p <.0001). The mean positional error drifted 0.11 mm/wk upward during the treatment course for patients using the 3DOF head positioner (p = .057). No positional drift was observed in the patients without the 3DOF head positioner. Conclusion: Our initial clinical experience with optically guided head-and-neck fractionated radiotherapy was promising and demonstrated clinical feasibility. The optically guided setup was especially useful when used in conjunction with the 3DOF head positioner and when it was recalibrated to the shifts using the weekly portal images.

  10. SU-E-T-132: Dosimetric Impact of Positioning Errors in Hypo-Fractionated Cranial Radiation Therapy Using Frameless Stereotactic BrainLAB System

    SciTech Connect

    Keeling, V; Jin, H; Ali, I; Ahmad, S

    2014-06-01

    Purpose: To determine dosimetric impact of positioning errors in the stereotactic hypo-fractionated treatment of intracranial lesions using 3Dtransaltional and 3D-rotational corrections (6D) frameless BrainLAB ExacTrac X-Ray system. Methods: 20 cranial lesions, treated in 3 or 5 fractions, were selected. An infrared (IR) optical positioning system was employed for initial patient setup followed by stereoscopic kV X-ray radiographs for position verification. 6D-translational and rotational shifts were determined to correct patient position. If these shifts were above tolerance (0.7 mm translational and 1° rotational), corrections were applied and another set of X-rays was taken to verify patient position. Dosimetric impact (D95, Dmin, Dmax, and Dmean of planning target volume (PTV) compared to original plans) of positioning errors for initial IR setup (XC: Xray Correction) and post-correction (XV: X-ray Verification) was determined in a treatment planning system using a method proposed by Yue et al. (Med. Phys. 33, 21-31 (2006)) with 3D-translational errors only and 6D-translational and rotational errors. Results: Absolute mean translational errors (±standard deviation) for total 92 fractions (XC/XV) were 0.79±0.88/0.19±0.15 mm (lateral), 1.66±1.71/0.18 ±0.16 mm (longitudinal), 1.95±1.18/0.15±0.14 mm (vertical) and rotational errors were 0.61±0.47/0.17±0.15° (pitch), 0.55±0.49/0.16±0.24° (roll), and 0.68±0.73/0.16±0.15° (yaw). The average changes (loss of coverage) in D95, Dmin, Dmax, and Dmean were 4.5±7.3/0.1±0.2%, 17.8±22.5/1.1±2.5%, 0.4±1.4/0.1±0.3%, and 0.9±1.7/0.0±0.1% using 6Dshifts and 3.1±5.5/0.0±0.1%, 14.2±20.3/0.8±1.7%, 0.0±1.2/0.1±0.3%, and 0.7±1.4/0.0±0.1% using 3D-translational shifts only. The setup corrections (XC-XV) improved the PTV coverage by 4.4±7.3% (D95) and 16.7±23.5% (Dmin) using 6D adjustment. Strong correlations were observed between translation errors and deviations in dose coverage for XC. Conclusion

  11. Fiducial-free CyberKnife stereotactic body radiation therapy (SBRT) for single vertebral body metastases: acceptable local control and normal tissue tolerance with 5 fraction approach.

    PubMed

    Gill, Beant; Oermann, Eric; Ju, Andrew; Suy, Simeng; Yu, Xia; Rabin, Jennifer; Kalhorn, Christopher; Nair, Mani N; Voyadzis, Jean-Marc; Unger, Keith; Collins, Sean P; Harter, K W; Collins, Brian T

    2012-01-01

    This retrospective analysis examines the local control and toxicity of five-fraction fiducial-free CyberKnife stereotactic body radiation therapy (SBRT) for single vertebral body (VB) metastases. All patients had favorable performance status (ECOG 0-1), oligometastatic disease, and no prior spine irradiation. A prescribed dose of 30-35 Gy was delivered in five fractions to the planning target volume (PTV) using the CyberKnife with X-sight spine tracking. Suggested maximum spinal cord and esophagus point doses were 30 and 40 Gy, respectively. A median 30 Gy (IQR, 30-35 Gy) dose was delivered to a median prescription isodose line of 70% (IQR, 65-77%) to 20 patients. At 34 months median follow-up (IQR, 25-40 months) for surviving patients, the 1- and 2-year Kaplan-Meier local control estimates were 80 and 73%, respectively. Two of the five local failures were infield in patients who had received irradiation to the gross tumor volume and three were paravertebral failures just outside the PTV in patients with prior corpectomy. No local failures occurred in patients who completed VB radiation alone. The 1- and 2-year Kaplan-Meier overall survival estimates were 80 and 57%, respectively. Most deaths were attributed to metastatic disease; one death was attributed to local recurrence. The mean maximum point doses were 26.4 Gy (SD, 5.1 Gy) to the spinal cord and 29.1 Gy (SD, 8.9 Gy) to the esophagus. Patients receiving maximum esophagus point doses greater than 35 Gy experienced acute dysphagia (Grade I/II). No spinal cord toxicity was documented. Five-fraction fiducial-free CyberKnife SBRT is an acceptable treatment option for newly diagnosed VB metastases with promising local control rates and minimal toxicity despite the close proximity of such tumors to the spinal cord and esophagus. A prospective study aimed at further enhancing local control by targeting the intact VB and escalating the total dose is planned.

  12. Alpha/Beta Ratio for Normal Lung Tissue as Estimated From Lung Cancer Patients Treated With Stereotactic Body and Conventionally Fractionated Radiation Therapy

    SciTech Connect

    Scheenstra, Alize E.H.; Rossi, Maddalena M.G.; Belderbos, José S.A.; Damen, Eugène M.F.; Lebesque, Joos V.; Sonke, Jan-Jakob

    2014-01-01

    Purpose: To estimate the α/β ratio for which the dose-dependent lung perfusion reductions for stereotactic body radiation therapy (SBRT) and conventionally fractionated radiation therapy (CFRT) are biologically equivalent. Methods and Materials: The relations between local dose and perfusion reduction 4 months after treatment in lung cancer patients treated with SBRT and CFRT were scaled according to the linear-quadratic model using α/β ratios from 0 Gy to ∞ Gy. To test for which α/β ratio both treatments have equal biological effect, a 5-parameter logistic model was optimized for both dose–effect relationships simultaneously. Beside the α/β ratio, the other 4 parameters were d{sub 50}, the steepness parameter k, and 2 parameters (M{sub SBRT} and M{sub CFRT}) representing the maximal perfusion reduction at high doses for SBRT and CFRT, respectively. Results: The optimal fitted model resulted in an α/β ratio of 1.3 Gy (0.5-2.1 Gy), M{sub SBRT} = 42.6% (40.4%-44.9%), M{sub CFRT} = 66.9% (61.6%-72.1%), d{sub 50} = 35.4 Gy (31.5-9.2 Gy), and k = 2.0 (1.7-2.3). Conclusions: An equal reduction of lung perfusion in lung cancer was observed in SBRT and CFRT if local doses were converted by the linear-quadratic model with an α/β ratio equal to 1.3 Gy (0.5-2.1 Gy)

  13. Tumor Shrinkage Assessed by Volumetric MRI in Long-Term Follow-Up After Fractionated Stereotactic Radiotherapy of Nonfunctioning Pituitary Adenoma

    SciTech Connect

    Kopp, Christine; Theodorou, Marilena; Poullos, Nektarios; Jacob, Vesna; Astner, Sabrina T.; Molls, Michael; Grosu, Anca-Ligia

    2012-03-01

    Purpose: To evaluate tumor control and side effects associated with fractionated stereotactic radiotherapy (FSRT) in the management of residual or recurrent nonfunctioning pituitary adenomas (NFPAs). Methods and Materials: We assessed exact tumor volume shrinkage in 16 patients with NFPA after FSRT. All patients had previously undergone surgery. Gross tumor volume (GTV) was outlined on contrast-enhanced magnetic resonance imaging (MRI) before and median 63 months (range, 28-100 months) after FSRT. MRI was performed as an axial three-dimensional gradient echo T1-weighted sequence at 1.6-mm slice thickness without gap (3D MRI). Results: Mean tumor size of all 16 pituitary adenomas before treatment was 7.4 mL (3.3-18.9 mL). We found shrinkage of the treated pituitary adenoma in all patients. Within a median follow-up of 63 months (28-100 months) an absolute mean volume reduction of 3.8 mL (0.9-12.4 mL) was seen. The mean relative size reduction compared with the volume before radiotherapy was 51% (22%-95%). Shrinkage measured by 3D MRI was greater at longer time intervals after radiotherapy. A strong negative correlation between the initial tumor volume and the absolute volume reduction after FSRT was found. There was no correlation between tumor size reduction and patient age, sex, or number of previous surgeries. Conclusions: By using 3D MRI in all patients undergoing FSRT of an NFPA, tumor shrinkage is detected. Our data demonstrate that volumetric assessment based on 3D MRI adds additional information to routinely used radiological response measurements. After FSRT a mean relative size reduction of 51% can be expected within 5 years.

  14. A Retrospective Review of CyberKnife Stereotactic Body Radiotherapy for Adrenal Tumors (Primary and Metastatic): Winthrop University Hospital Experience.

    PubMed

    Desai, Amishi; Rai, Hema; Haas, Jonathan; Witten, Matthew; Blacksburg, Seth; Schneider, Jeffrey G

    2015-01-01

    The adrenal gland is a common site of cancer metastasis. Surgery remains a mainstay of treatment for solitary adrenal metastasis. For patients who cannot undergo surgery, radiation is an alternative option. Stereotactic body radiotherapy (SBRT) is an ablative treatment option allowing larger doses to be delivered over a shorter period of time. In this study, we report on our experience with the use of SBRT to treat adrenal metastases using CyberKnife technology. We retrospectively reviewed the Winthrop University radiation oncology data base to identify 14 patients for whom SBRT was administered to treat malignant adrenal disease. Of the factors examined, the biological equivalent dose (BED) of radiation delivered was found to be the most important predictor of local adrenal tumor control. We conclude that CyberKnife-based SBRT is a safe, non-invasive modality that has broadened the therapeutic options for the treatment of isolated adrenal metastases.

  15. Circumferential or sectored beam arrangements for stereotactic body radiation therapy (SBRT) of primary lung tumors: Effect on target and normal-structure dose-volume metrics

    SciTech Connect

    Rosenberg, Mara W.; Kato, Catherine M.; Carson, Kelly M.P.; Matsunaga, Nathan M.; Arao, Robert F.; Doss, Emily J.; McCracken, Charles L.; Meng, Lu Z.; Chen, Yiyi; Laub, Wolfram U.; Fuss, Martin; Tanyi, James A.

    2013-01-01

    To compare 2 beam arrangements, sectored (beam entry over ipsilateral hemithorax) vs circumferential (beam entry over both ipsilateral and contralateral lungs), for static-gantry intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) delivery techniques with respect to target and organs-at-risk (OAR) dose-volume metrics, as well as treatment delivery efficiency. Data from 60 consecutive patients treated using stereotactic body radiation therapy (SBRT) for primary non–small-cell lung cancer (NSCLC) formed the basis of this study. Four treatment plans were generated per data set: IMRT/VMAT plans using sectored (-s) and circumferential (-c) configurations. The prescribed dose (PD) was 60 Gy in 5 fractions to 95% of the planning target volume (PTV) (maximum PTV dose ∼ 150% PD) for a 6-MV photon beam. Plan conformality, R{sub 50} (ratio of volume circumscribed by the 50% isodose line and the PTV), and D{sub 2} {sub cm} (D{sub max} at a distance ≥2 cm beyond the PTV) were evaluated. For lungs, mean doses (mean lung dose [MLD]) and percent V{sub 30}/V{sub 20}/V{sub 10}/V{sub 5} Gy were assessed. Spinal cord and esophagus D{sub max} and D{sub 5}/D{sub 50} were computed. Chest wall (CW) D{sub max} and absolute V{sub 30}/V{sub 20}/V{sub 10}/V{sub 5} {sub Gy} were reported. Sectored SBRT planning resulted in significant decrease in contralateral MLD and V{sub 10}/V{sub 5} {sub Gy}, as well as contralateral CW D{sub max} and V{sub 10}/V{sub 5} {sub Gy} (all p < 0.001). Nominal reductions of D{sub max} and D{sub 5}/D{sub 50} for the spinal cord with sectored planning did not reach statistical significance for static-gantry IMRT, although VMAT metrics did show a statistically significant decrease (all p < 0.001). The respective measures for esophageal doses were significantly lower with sectored planning (p < 0.001). Despite comparable dose conformality, irrespective of planning configuration, R{sub 50} significantly improved with IMRT

  16. Cost-Effectiveness Analysis of Single Fraction of Stereotactic Body Radiation Therapy Compared With Single Fraction of External Beam Radiation Therapy for Palliation of Vertebral Bone Metastases

    SciTech Connect

    Kim, Hayeon; Rajagopalan, Malolan S.; Beriwal, Sushil; Huq, M. Saiful; Smith, Kenneth J.

    2015-03-01

    Purpose: Stereotactic body radiation therapy (SBRT) has been proposed for the palliation of painful vertebral bone metastases because higher radiation doses may result in superior and more durable pain control. A phase III clinical trial (Radiation Therapy Oncology Group 0631) comparing single fraction SBRT with single fraction external beam radiation therapy (EBRT) in palliative treatment of painful vertebral bone metastases is now ongoing. We performed a cost-effectiveness analysis to compare these strategies. Methods and Materials: A Markov model, using a 1-month cycle over a lifetime horizon, was developed to compare the cost-effectiveness of SBRT (16 or 18 Gy in 1 fraction) with that of 8 Gy in 1 fraction of EBRT. Transition probabilities, quality of life utilities, and costs associated with SBRT and EBRT were captured in the model. Costs were based on Medicare reimbursement in 2014. Strategies were compared using the incremental cost-effectiveness ratio (ICER), and effectiveness was measured in quality-adjusted life years (QALYs). To account for uncertainty, 1-way, 2-way and probabilistic sensitivity analyses were performed. Strategies were evaluated with a willingness-to-pay (WTP) threshold of $100,000 per QALY gained. Results: Base case pain relief after the treatment was assumed as 20% higher in SBRT. Base case treatment costs for SBRT and EBRT were $9000 and $1087, respectively. In the base case analysis, SBRT resulted in an ICER of $124,552 per QALY gained. In 1-way sensitivity analyses, results were most sensitive to variation of the utility of unrelieved pain; the utility of relieved pain after initial treatment and median survival were also sensitive to variation. If median survival is ≥11 months, SBRT cost <$100,000 per QALY gained. Conclusion: SBRT for palliation of vertebral bone metastases is not cost-effective compared with EBRT at a $100,000 per QALY gained WTP threshold. However, if median survival is ≥11 months, SBRT costs ≤$100

  17. Prostate-specific antigen kinetics following hypofractionated stereotactic body radiotherapy boost as post-external beam radiotherapy versus conventionally fractionated external beam radiotherapy for localized prostate cancer

    PubMed Central

    Phak, Jeong Hoon; Kim, Hun Jung; Kim, Woo Chul

    2015-01-01

    Background Stereotactic body radiotherapy (SBRT) has emerged as an effective treatment for localized prostate cancer. The purpose of this study was to compare the prostate-specific antigen (PSA) kinetics between conventionally fractionated external beam radiotherapy (CF-EBRT) and SBRT boost after whole pelvis EBRT (WP-EBRT) in localized prostate cancer. Methods A total of 77 patients with localized prostate cancer [T-stage, T1–T3; Gleason score (GS) 5–9; PSA < 20 ng/mL] were enrolled. A total of 35 patients were treated with SBRT boost (21 Gy in 3 fractions) after WP-EBRT and 42 patients were treated with CF-EBRT (45 Gy WP-EBRT and boost of 25.2–30.6 Gy in 1.8-Gy fractions). PSA nadir and rate of change in PSA (slope) were calculated and compared. Results With a median follow-up of 52.4 months (range, 14–74 months), the median PSA nadir and slope for SBRT boost were 0.29 ng/mL and −0.506, −0.235, −0.129, and −0.092 ng/mL/mo, respectively, for durations of 1 year, 2 years, 3 years, and 4 years postradiotherapy. Similarly, for CF-EBRT, the median PSA nadir and slopes were 0.39 ng/mL and −0.720 ng/mL/mo, −0.204 ng/mL/mo, −0.121 ng/mL/mo, and −0.067 ng/mL/mo, respectively. The slope of CF-EBRT was significantly different with a greater median rate of change for 1 year postradiotherapy than that of SBRT boost (P = 0.018). Contrastively, the slopes of SBRT boost for durations of 2 years, 3 years, and 4 years tended to be continuously greater than that of CF-EBRT. The significantly lower PSA nadir was observed in SBRT boost (median nadir 0.29 ng/mL) compared with CF-EBRT (median nadir 0.35 ng/mL, P = 0.025). Five-year biochemical failure (BCF) free survival was 94.3% for SBRT boost and 78.6% for CF-EBRT (P = 0.012). Conclusion Patients treated with SBRT boost after WP-EBRT experienced a lower PSA nadir and there tended to be a continuously greater rate of decline of PSA for durations of 2 years, 3 years, and

  18. Clinical Assessment Of Stereotactic IGRT: Spinal Radiosurgery

    SciTech Connect

    Gerszten, Peter C. Burton, Steven A.

    2008-07-01

    The role of stereotactic radiosurgery for the treatment of intracranial lesions is well established. Its use for the treatment of spinal lesions has been limited because of the availability of effective target immobilization devices. Recent advances in stereotactic IGRT have allowed for spinal applications. Large clinical experience with spinal radiosurgery to properly assess clinical outcomes has previously been limited. At our institution, we have developed a successful multidisciplinary spinal radiosurgery program in which 542 spinal lesions (486 malignant and 56 benign lesions) were treated with a single-fraction radiosurgery technique. Patient ages ranged from 18 to 85 years (mean 56 years). Lesion location included 92 cervical, 234 thoracic, 130 lumbar, and 86 sacral. The most common metastatic tumors were renal cell (89 cases), breast (74 cases), and lung (71 cases). The most common benign tumors were neurofibroma (24 cases), schwannoma (13 cases), and meningioma (7 cases). Eighty-nine cervical lesions were treated using skull tracking. Thoracic, lumbar, and sacral tumors were tracked relative to either gold or stainless steel fiducial markers. The maximum intratumoral dose ranged from 12.5 to 30 Gy (mean 20 Gy). Tumor volume ranged from 0.16 to 298 mL (mean 47 mL). Three hundred thirty-seven lesions had received prior external beam irradiation with spinal cord doses precluding further conventional irradiation. The primary indication for radiosurgery was pain in 326 cases, as a primary treatment modality in 70 cases, for tumor radiographic tumor progression in 65 cases, for post-surgical treatment in 38 cases, for progressive neurological deficit in 35 cases, and as a radiation boost in 8 cases. Follow-up period was at least 3 to 49 months. Axial and/or radicular pain improved in 300 of 326 cases (92%). Long-term tumor control was demonstrated in 90% of lesions treated with radiosurgery as a primary treatment modality and in 88% of lesions treated for

  19. Radiation-induced second primary cancer risks from modern external beam radiotherapy for early prostate cancer: impact of stereotactic ablative radiotherapy (SABR), volumetric modulated arc therapy (VMAT) and flattening filter free (FFF) radiotherapy

    NASA Astrophysics Data System (ADS)

    Murray, Louise J.; Thompson, Christopher M.; Lilley, John; Cosgrove, Vivian; Franks, Kevin; Sebag-Montefiore, David; Henry, Ann M.

    2015-02-01

    Risks of radiation-induced second primary cancer following prostate radiotherapy using 3D-conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), flattening filter free (FFF) and stereotactic ablative radiotherapy (SABR) were evaluated. Prostate plans were created using 10 MV 3D-CRT (78 Gy in 39 fractions) and 6 MV 5-field IMRT (78 Gy in 39 fractions), VMAT (78 Gy in 39 fractions, with standard flattened and energy-matched FFF beams) and SABR (42.7 Gy in 7 fractions with standard flattened and energy-matched FFF beams). Dose-volume histograms from pelvic planning CT scans of three prostate patients, each planned using all 6 techniques, were used to calculate organ equivalent doses (OED) and excess absolute risks (EAR) of second rectal and bladder cancers, and pelvic bone and soft tissue sarcomas, using mechanistic, bell-shaped and plateau models. For organs distant to the treatment field, chamber measurements recorded in an anthropomorphic phantom were used to calculate OEDs and EARs using a linear model. Ratios of OED give relative radiation-induced second cancer risks. SABR resulted in lower second cancer risks at all sites relative to 3D-CRT. FFF resulted in lower second cancer risks in out-of-field tissues relative to equivalent flattened techniques, with increasing impact in organs at greater distances from the field. For example, FFF reduced second cancer risk by up to 20% in the stomach and up to 56% in the brain, relative to the equivalent flattened technique. Relative to 10 MV 3D-CRT, 6 MV IMRT or VMAT with flattening filter increased second cancer risks in several out-of-field organs, by up to 26% and 55%, respectively. For all techniques, EARs were consistently low. The observed large relative differences between techniques, in absolute terms, were very low, highlighting the importance of considering absolute risks alongside the corresponding relative risks, since when absolute

  20. Net primary production of forests: a constant fraction of gross primary production?

    PubMed

    Waring, R. H.; Landsberg, J. J.; Williams, M.

    1998-02-01

    Considerable progress has been made in our ability to model and measure annual gross primary production (GPP) by terrestrial vegetation. But challenges remain in estimating maintenance respiration (R(m)) and net primary production (NPP). To search for possible common relationships, we assembled annual carbon budgets from six evergreen and one deciduous forest in Oregon, USA, three pine plantations in New South Wales, Australia, a deciduous forest in Massachusetts, USA, and a Nothofagus forest on the South Island of New Zealand. At all 12 sites, a standard procedure was followed to estimate annual NPP of foliage, branches, stems, and roots, the carbon expended in synthesis of these organs (R(g)), their R(m), and that of previously produced foliage and sapwood in boles, branches, and large roots. In the survey, total NPP ranged from 120 to 1660 g C m(-2) year(-1), whereas the calculated fraction allocated to roots varied from 0.22 to 0.63. Comparative analysis indicated that the total NPP/GPP ratio was conservative (0.47 +/- 0.04 SD). This finding supports the possibility of greatly simplifying forest growth models. The constancy of the NPP/GPP ratio also provides an incentive to renew efforts to understand the environmental factors affecting partitioning of NPP above and belowground.

  1. [Long-term survival following resection of primary rectal cancer metachronous metastases and salvage surgeries for relapsed lesions after stereotactic body radiotherapy for lung metastases - a case report].

    PubMed

    Yokosuka, Tetsuya; Nakajima, Yasushi; Kobayashi, Toshiko; Takeda, Atsuya; Yasuno, Masamichi

    2014-11-01

    A 66-year-old man underwent abdominoperineal resection for rectal cancer in 2003, followed by liver resection for a solitary liver metastasis in 2005. In 2006, the patient underwent abdominal para-aortic lymph node dissection, which was performed concurrently with partial resections of 3 metastases in the right lung. New metastatic lesions were subsequently diagnosed in S8 of the right lung and S1+2 of the left lung. The patient underwent stereotactic body radiotherapy (SBRT) for both lesions. However, the lesions relapsed and salvage surgeries were subsequently performed. These included a partial resection in 2009 for the lesion in the right lung and an upper division segmentectomy in 2010 for the lesion in the left lung. Currently, 11 years after resection of the primary rectal cancer, the patient is asymptomatic, without any signs of recurrence. In this report, we describe the use of SBRT for the treatment of colorectal cancer pulmonary metastases, and the use of salvage surgery for relapsed lesions.

  2. Practical patterns for stereotactic body radiotherapy to hepatocellular carcinoma in Korea: a survey of the Korean Stereotactic Radiosurgery Group

    PubMed Central

    Bae, Sun Hyun; Kim, Mi-Sook; Jang, Won Il; Kay, Chul-Seung; Kim, Woochul; Kim, Eun Seog; Kim, Jin Ho; Kim, Jin Hee; Yang, Kwang Mo; Lee, Kyu Chan; Chang, A Ram; Jo, Sunmi

    2016-01-01

    Objective To investigate practical patterns for stereotactic body radiotherapy to hepatocellular carcinoma in Korea. Methods In June 2013, the Korean Stereotactic Radiosurgery Group of the Korean Society for Radiation Oncology conducted a national patterns-of-care survey about stereotactic body radiotherapy to the liver lesion in hepatocellular carcinoma, consisting of 19 questions and 2 clinical scenarios. Results All 208 radiation oncologists (100%), who are regular members of Korean Society for Radiation Oncology, responded to this survey. Among these, 95 radiation oncologists were specialists for hepatology; 64 physicians did not use stereotactic body radiotherapy for hepatocellular carcinoma, and 31 physicians used stereotactic body radiotherapy. Most physicians (52%) performed stereotactic body radiotherapy to hepatocellular carcinoma in ≤5 cases per year. Physicians applied stereotactic body radiotherapy according to tumour size and baseline Child–Pugh class. All physicians agreed the use of stereotactic body radiotherapy to 2.8-cm hepatocellular carcinoma with Child–Pugh class of A, while 23 physicians (74%) selected stereotactic body radiotherapy for Child–Pugh class of B. Nineteen physicians (61%) selected stereotactic body radiotherapy to 5-cm hepatocellular carcinoma with Child–Pugh class of A, and only 14 physicians (45%) selected stereotactic body radiotherapy for Child–Pugh class of B. On the other hand, the preferred dose scheme was same as 60 Gy in three fractions. Conclusions Among radiation oncologists in Korea, there was diversity in the practice for stereotactic body radiotherapy to the liver lesion in hepatocellular carcinoma. Additional prospective studies are necessary to standardize the practice and establish Korea-specific practice guidelines for hepatocellular carcinoma stereotactic body radiotherapy. PMID:26826720

  3. Differences in rates of radiation-induced true and false rib fractures after stereotactic body radiation therapy for Stage I primary lung cancer

    PubMed Central

    Miura, Hideharu; Inoue, Toshihiko; Shiomi, Hiroya; Oh, Ryoong-Jin

    2015-01-01

    The purpose of this study was to analyze the dosimetry and investigate the clinical outcomes of radiation-induced rib fractures (RIRFs) after stereotactic body radiotherapy (SBRT). A total of 126 patients with Stage I primary lung cancer treated with SBRT, who had undergone follow-up computed tomography (CT) at least 12 months after SBRT and who had no previous overlapping radiation exposure were included in the study. We used the Mantel–Haenszel method and multiple logistic regression analysis to compare risk factors. We analyzed D(0.5 cm3) (minimum absolute dose received by a 0.5-cm3 volume) and identified each rib that received a biologically effective dose (BED) (BED3, using the linear–quadratic (LQ) formulation assuming an α/β = 3) of at least 50 Gy. Of the 126 patients, 46 (37%) suffered a total of 77 RIRFs. The median interval from SBRT to RIRF detection was 15 months (range, 3–56 months). The 3-year cumulative probabilities were 45% (95% CI, 34–56%) and 3% (95% CI, 0–6%), for Grades 1 and 2 RIRFs, respectively. Multivariate analysis showed that tumor location was a statistically significant risk factor for the development of Grade 1 RIRFs. Of the 77 RIRFs, 71 (92%) developed in the true ribs (ribs 1–7), and the remaining six developed in the false ribs (ribs 8–12). The BED3 associated with 10% and 50% probabilities of RIRF were 55 and 210 Gy to the true ribs and 240 and 260 Gy to the false ribs. We conclude that RIRFs develop more frequently in true ribs than in false ribs. PMID:25504640

  4. Stereotactic radiosurgery

    MedlinePlus

    ... nerve that connects the ear to the brain ( acoustic neuroma ) Pituitary tumors Spinal cord tumors Other cancers ... PA: Elsevier Saunders; 2015:chap 179. Read More Acoustic neuroma Brain tumor - primary - adults Cerebral arteriovenous malformation ...

  5. High Dose-Per-Fraction Irradiation of Limited Lung Volumes Using an Image-Guided, Highly Focused Irradiator: Simulating Stereotactic Body Radiotherapy Regimens in a Small-Animal Model

    SciTech Connect

    Cho, Jaeho; Kodym, Reinhard; Seliounine, Serguei

    2010-07-01

    Purpose: To investigate the underlying biology associated with stereotactic body radiotherapy (SBRT), both in vivo models and image-guided, highly focal irradiation systems are necessary. Here, we describe such an irradiation system and use it to examine normal tissue toxicity in a small-animal model at lung volumes similar to those associated with human therapy. Methods and Materials: High-dose radiation was delivered to a small volume of the left lung of C3H/HeJCr mice using a small-animal stereotactic irradiator. The irradiator has a collimation mechanism to produce focal radiation beams, an imaging subsystem consisting of a fluorescent screen coupled to a charge-coupled device camera, and a manual positioning stage. Histopathologic examination and micro-CT were used to evaluate the radiation response. Results: Focal obliteration of the alveoli by fibrous connective tissue, hyperplasia of the bronchiolar epithelium, and presence of a small number of inflammatory cells are the main reactions to low-volume/high-dose irradiation of the mouse lung. The tissue response suggested a radiation dose threshold for early phase fibrosis lying between 40 and 100 Gy. The irradiation system satisfied our requirements of high-dose-rate, small beam diameter, and precise localization and verification. Conclusions: We have established an experimental model and image-guided animal irradiation system for the study of high dose per fraction irradiations such as those used with SBRT at volumes analogous to those used in human beings. It will also allow the targeting of specific anatomical structures of the thorax or ultimately, orthotopic tumors of the lung.

  6. Analyzing Pre-Service Primary Teachers' Fraction Knowledge Structures through Problem Posing

    ERIC Educational Resources Information Center

    Kilic, Cigdem

    2015-01-01

    In this study it was aimed to determine pre-service primary teachers' knowledge structures of fraction through problem posing activities. A total of 90 pre-service primary teachers participated in this study. A problem posing test consisting of two questions was used and the participants were asked to generate as many as problems based on the…

  7. Effect of Cuisenaire Rods' Approach on Some Nigeria Primary Pupils' Achievement in Decimal Fractions

    ERIC Educational Resources Information Center

    Kurumeh, M. S. C.; Achor, E. E.

    2008-01-01

    This study determined the effect of Cuisenaire Rods' approach on some Nigeria primary pupils' achievement in decimal fractions. Three hypotheses guided the study. A total of 200 Primary six pupils (that is, 6th grade) from randomly selected schools in Makurdi metropolis of Benue State of Nigeria served as the sample for the study. A Mathematics…

  8. Stereotactic Body Radiotherapy for Oligometastatic Lung Tumors

    SciTech Connect

    Norihisa, Yoshiki; Nagata, Yasushi Takayama, Kenji; Matsuo, Yukinori; Sakamoto, Takashi; Sakamoto, Masato; Mizowaki, Takashi; Yano, Shinsuke; Hiraoka, Masahiro

    2008-10-01

    Purpose: Since 1998, we have treated primary and oligometastatic lung tumors with stereotactic body radiotherapy (SBRT). The term 'oligometastasis' is used to indicate a small number of metastases limited to an organ. We evaluated our clinical experience of SBRT for oligometastatic lung tumors. Methods and Materials: A total of 34 patients with oligometastatic lung tumors were included in this study. The primary involved organs were the lung (n = 15), colorectum (n = 9), head and neck (n = 5), kidney (n = 3), breast (n = 1), and bone (n = 1). Five to seven, noncoplanar, static 6-MV photon beams were used to deliver 48 Gy (n = 18) or 60 Gy (n = 16) at the isocenter, with 12 Gy/fraction within 4-18 days (median, 12 days). Results: The overall survival rate, local relapse-free rate, and progression-free rate at 2 years was 84.3%, 90.0%, and 34.8%, respectively. No local progression was observed in tumors irradiated with 60 Gy. SBRT-related pulmonary toxicities were observed in 4 (12%) Grade 2 cases and 1 (3%) Grade 3 case. Patients with a longer disease-free interval had a greater overall survival rate. Conclusion: The clinical result of SBRT for oligometastatic lung tumors in our institute was comparable to that after surgical metastasectomy; thus, SBRT could be an effective treatment of pulmonary oligometastases.

  9. Stereotactic radiotherapy for malignancies involving the trigeminal and facial nerves.

    PubMed

    Cuneo, K C; Zagar, T M; Brizel, D M; Yoo, D S; Hoang, J K; Chang, Z; Wang, Z; Yin, F F; Das, S K; Green, S; Ready, N; Bhatti, M T; Kaylie, D M; Becker, A; Sampson, J H; Kirkpatrick, J P

    2012-06-01

    Involvement of a cranial nerve caries a poor prognosis for many malignancies. Recurrent or residual disease in the trigeminal or facial nerve after primary therapy poses a challenge due to the location of the nerve in the skull base, the proximity to the brain, brainstem, cavernous sinus, and optic apparatus and the resulting complex geometry. Surgical resection caries a high risk of morbidity and is often not an option for these patients. Stereotactic radiosurgery and radiotherapy are potential treatment options for patients with cancer involving the trigeminal or facial nerve. These techniques can deliver high doses of radiation to complex volumes while sparing adjacent critical structures. In the current study, seven cases of cancer involving the trigeminal or facial nerve are presented. These patients had unresectable recurrent or residual disease after definitive local therapy. Each patient was treated with stereotactic radiation therapy using a linear accelerator based system. A multidisciplinary approach including neuroradiology and surgical oncology was used to delineate target volumes. Treatment was well tolerated with no acute grade 3 or higher toxicity. One patient who was reirradiated experienced cerebral radionecrosis with mild symptoms. Four of the seven patients treated had no evidence of disease after a median follow up of 12 months (range 2-24 months). A dosimetric analysis was performed to compare intensity modulated fractionated stereotactic radiation therapy (IM-FSRT) to a 3D conformal technique. The dose to 90% (D90) of the brainstem was lower with the IM-FSRT plan by a mean of 13.5 Gy. The D95 to the ipsilateral optic nerve was also reduced with IM-FSRT by 12.2 Gy and the D95 for the optic chiasm was lower with FSRT by 16.3 Gy. Treatment of malignancies involving a cranial nerve requires a multidisciplinary approach. Use of an IM-FSRT technique with a micro-multileaf collimator resulted in a lower dose to the brainstem, optic nerves and chiasm

  10. Understanding the Teaching and Learning of Fractions: A South African Primary School Case Study

    ERIC Educational Resources Information Center

    Brijlall, Deonarain; Maharaj, Aneshkumar; Molebale, Justin

    2011-01-01

    The authors explored the teaching and learning of fractions by reflecting on teachers and learners' views on practical work and their classroom practices. The teachers and learners were from two primary schools in a rural area in KwaZulu-Natal (South Africa). Questionnaires, in which teachers and learners expressed their views on practical work…

  11. Application of polymer-gel dosimetry in stereotactic radiosurgery

    NASA Astrophysics Data System (ADS)

    Novotny, J., Jr.; Spevacek, V.; Dvorak, P.; Hrbacek, J.; Novotny, J.; Tlachacova, D.; Schmitt, M.; Vymazal, J.; Tintera, J.; Cechak, T.

    2004-01-01

    Stereotactic irradiation with the Leksell gamma knife (Elekta Instrument AB, Stockholm, Sweden) is one of the primary methods used for the stereotactic radiosurgery treatment of intracranial lesions. To assure the quality of the whole treatment procedure a proper dosimetric system is required. The polymer-gel dosimeter evaluated by nuclear magnetic resonance (NMR) is a promising tool to satisfy this requirement. The purpose of this study was to investigate the use of polymer-gel dosimeter as a dosimetric tool for the quality control of stereotactic radiosurgery procedures performed by the Leksell gamma knife.

  12. Spatially resolved intake fraction estimates for primary and secondary particulate matter in the United States

    NASA Astrophysics Data System (ADS)

    Lamancusa, Carmen; Parvez, Fatema; Wagstrom, Kristina

    2017-02-01

    This study uses intake fraction, the fraction of emissions that are inhaled from a given source, to quantify how emissions from different regions proportionally contribute to human exposure to both primary and secondary particulate matter species. The intake fraction for secondary species is defined using the common atomic constituents between precursor species and products, allowing estimates to include both primary and secondary species. The Particulate Matter Source Apportionment Technology (PSAT) in the Comprehensive Air Quality Model with Extensions (CAMx) regional air quality model is used to calculate the intake fraction for twenty-five source regions throughout the contiguous United States over four seasons. The calculations use spatially explicit emissions and population density to more accurately capture the variation in intake fraction between regions. The spatially explicit emissions allow for the calculation of spatial trends and variations within the intake fraction. More specifically it allows for the calculation of the amount of intake that occurs within a given distance of the emissions source or source region. Based on the results sulfate inhalation occurs over larger distances than other particulate matter species. For most regions, a substantial fraction (>75%) of the inhalation occurs within 50 km for all seasons, demonstrating that efforts to reduce emissions will have the largest health impact on the local community. Furthermore the distance over which 75% of the inhalation occurs increases by 20% for all species during the winter and a larger percentage of pollutants emitted during the winter are inhaled relative to pollutants emitted during other seasons. This demonstrates that emission reductions during the winter will have a greater impact on health than reductions during other seasons.

  13. Vemurafenib and concomitant stereotactic radiation for the treatment of melanoma with spinal metastases: A case report

    PubMed Central

    Stefan, Dinu; Popotte, Hosni; Stefan, Andreea Raluca; Tesniere, Audrey; Tomaszewski, Aurélie; Lesueur, Paul; Habrand, Jean-Louis; Verneuil, Laurence

    2016-01-01

    A 56-year-old man with BRAFV600E melanoma and spinal metastases treated with vemurafenib and stereotactic radiation showed a partial response without neurological, skin or mucosal toxicity, 8 months after completion of this combination. This case suggests that stereotactic radiation spares normal tissues and might be safer than conventional fractionated radiation with vemurafenib. PMID:26900362

  14. Vemurafenib and concomitant stereotactic radiation for the treatment of melanoma with spinal metastases: A case report.

    PubMed

    Stefan, Dinu; Popotte, Hosni; Stefan, Andreea Raluca; Tesniere, Audrey; Tomaszewski, Aurélie; Lesueur, Paul; Habrand, Jean-Louis; Verneuil, Laurence

    2016-01-01

    A 56-year-old man with BRAFV600E melanoma and spinal metastases treated with vemurafenib and stereotactic radiation showed a partial response without neurological, skin or mucosal toxicity, 8 months after completion of this combination. This case suggests that stereotactic radiation spares normal tissues and might be safer than conventional fractionated radiation with vemurafenib.

  15. Scatter-to-primary based scatter fractions for transmission-dependent convolution subtraction of SPECT images.

    PubMed

    Larsson, Anne; Johansson, Lennart

    2003-11-21

    In single photon emission computed tomography (SPECT), transmission-dependent convolution subtraction has been shown to be useful when correcting for scattered events. The method is based on convolution subtraction, but includes a matrix of scatter fractions instead of a global scatter fraction. The method can be extended to iteratively improve the scatter estimate, but in this note we show that this requires a modification of the theory to use scatter-to-total scatter fractions for the first iteration only and scatter-to-primary fractions thereafter. To demonstrate this, scatter correction is performed on a Monte Carlo simulated image of a point source of activity in water. The modification of the theory is compared to corrections where the scatter fractions are based on the scatter-to-total ratio, using one and ten iterations. The resulting ratios of subtracted to original counts are compared to the true scatter-to-total ratio of the simulation and the most accurate result is found for our modification of the theory.

  16. Impact of soil primary size fractions on sorption and desorption of atrazine on organo-mineral fractions.

    PubMed

    Huang, Yufen; Liu, Zhongzhen; He, Yan; Li, Yanliang

    2015-03-01

    In the current study, a mechanical dispersion method was employed to separate clay (<2 μm), silt (2-20 μm), and sand (20-50 μm) fraction in six bulk soils. Batch equilibrium method was used to conduct atrazine sorption and desorption experiments on soil organo-mineral fractions with bulk soils and their contrasting size fractions separately. The potential contribution of total organic carbon (TOC) for atrazine retention in different fractions was further investigated. It was found that clay fraction had the highest adsorption but the least desorption capacities for atrazine, while sand fraction had the lowest adsorption but the highest desorption capacities for atrazine. The adsorption percentage of atrazine, as compared with adsorption by the corresponding bulk soils, ranged from 53.6 to 80.5%, 35.7 to 56.4%, and 0.2 to 4.5% on the clay, silt, and sand fractions, respectively. TOC was one of the key factors affecting atrazine retention in soils, with the exact contribution dependent on varying degree of coating with mineral component in different soil size fractions. The current study may be useful to predict the bioavailability of atrazine in different soil size fractions.

  17. Frameless Image-Guided Intracranial Stereotactic Radiosurgery: Clinical Outcomes for Brain Metastases

    SciTech Connect

    Breneman, John C. Steinmetz, Ryan; Smith, Aaron; Lamba, Michael; Warnick, Ronald E.

    2009-07-01

    Purpose: After preclinical investigations confirming the accuracy of target localization by frameless image-guided radiosurgery, we report the clinical outcomes of patients with brain metastases who underwent frameless radiosurgery. Methods and Materials: Between 2005 and 2006, 53 patients underwent frameless stereotactic radiosurgery using a linear accelerator equipped with on-board image guidance for the treatment of 158 brain metastases. The radiation doses were delivered in a single fraction (dose range, 12-22 Gy; median, 18). Patients were followed with magnetic resonance imaging scans at 2-3-month intervals. Progression-free survival was the primary study endpoint. Results: With a median follow-up of 38 weeks (range, 14-112), the overall survival rate was 70% at 6 months, 44% at 1 year, 29% at 18 months, and 16% at 24 months. Local control was achieved in 90% of 168 treated lesions at 6 months, 80% at 12 months, 78% at 18 months, and 78% at 24 months. Local control tended to be improved in lesions treated with {>=}18 Gy and for lesions <0.2 cm{sup 3}. Adverse events occurred in 5 patients (9.6%). No evidence of imaging changes on post-stereotactic radiosurgery scans was found to suggest mistargeting of a radiation isocenter. Conclusion: The clinical outcomes after frameless stereotactic radiosurgery were comparable to those after frame-based radiosurgery techniques. Given its significant advantages in terms of patient comfort, ability to use fractionated treatment regimens, and convenience in scheduling of personnel and equipment resources, frameless radiosurgery will likely become a common technique for intracranial radiosurgery.

  18. Stereotactic surgery for eating disorders

    PubMed Central

    Sun, Bomin; Liu, Wei

    2013-01-01

    Eating disorders (EDs) are a group of severely impaired eating behaviors, which include three subgroups: anorexia nervosa (AN), bulimia nervosa (BN), and ED not otherwise specified (EDNOS). The precise mechanism of EDs is still unclear and the disorders cause remarkable agony for the patients and their families. Although there are many available treatment methods for EDs today, such as family therapy, cognitive behavioral therapy, medication, psychotherapy, and so on, almost half of the patients are refractory to all current medical treatment and never fully recover. For treatment-refractory EDs, stereotactic surgery may be an alternative therapy. This review discusses the history of stereotactic surgery, the modern procedures, and the mostly used targets of stereotactic surgery in EDs. In spite of the limited application of stereotactic surgery in ED nowadays, stereotactic lesion and deep brain stimulation (DBS) are promising treatments with the development of modern functional imaging techniques and the increasing understanding of its mechanism in the future. PMID:23682343

  19. Stereotactic surgery for eating disorders.

    PubMed

    Sun, Bomin; Liu, Wei

    2013-01-01

    EATING DISORDERS (EDS) ARE A GROUP OF SEVERELY IMPAIRED EATING BEHAVIORS, WHICH INCLUDE THREE SUBGROUPS: anorexia nervosa (AN), bulimia nervosa (BN), and ED not otherwise specified (EDNOS). The precise mechanism of EDs is still unclear and the disorders cause remarkable agony for the patients and their families. Although there are many available treatment methods for EDs today, such as family therapy, cognitive behavioral therapy, medication, psychotherapy, and so on, almost half of the patients are refractory to all current medical treatment and never fully recover. For treatment-refractory EDs, stereotactic surgery may be an alternative therapy. This review discusses the history of stereotactic surgery, the modern procedures, and the mostly used targets of stereotactic surgery in EDs. In spite of the limited application of stereotactic surgery in ED nowadays, stereotactic lesion and deep brain stimulation (DBS) are promising treatments with the development of modern functional imaging techniques and the increasing understanding of its mechanism in the future.

  20. Global intraurban intake fractions for primary air pollutants from vehicles and other distributed sources.

    PubMed

    Apte, Joshua S; Bombrun, Emilie; Marshall, Julian D; Nazaroff, William W

    2012-03-20

    We model intraurban intake fraction (iF) values for distributed ground-level emissions in all 3646 global cities with more than 100,000 inhabitants, encompassing a total population of 2.0 billion. For conserved primary pollutants, population-weighted median, mean, and interquartile range iF values are 26, 39, and 14-52 ppm, respectively, where 1 ppm signifies 1 g inhaled/t emitted. The global mean urban iF reported here is roughly twice as large as previous estimates for cities in the United States and Europe. Intake fractions vary among cities owing to differences in population size, population density, and meteorology. Sorting by size, population-weighted mean iF values are 65, 35, and 15 ppm, respectively, for cities with populations larger than 3, 0.6-3, and 0.1-0.6 million. The 20 worldwide megacities (each >10 million people) have a population-weighted mean iF of 83 ppm. Mean intraurban iF values are greatest in Asia and lowest in land-rich high-income regions. Country-average iF values vary by a factor of 3 among the 10 nations with the largest urban populations.

  1. Primary ion dependence of LiF direct recoil intensities and ion fractions

    NASA Astrophysics Data System (ADS)

    Chen, J. N.; Shi, M.; Rabalais, J. W.

    1987-02-01

    Time-of-flight (TOF) spectra of the scattered and recoiled particles resulting from 1-10 keV He+, Ne+, Ar+, Kr+, and Xe+ ions impingent on surfaces of LiF thin films have been obtained. Measurements of directly recoiled (DR) neutrals plus ions and neutrals alone are used to calculate positive and negative ion fractions Y+,- from DR events. The oppositely charged ion fractions have a distinctly different behavior as a function of kinetic energy. The Y+ values exhibit a threshold at low energy followed by a plateau region at higher energy while the Y- values are maximum in the low energy region followed by a decreasing yield as energy increases. The energy dependence of Y+,- is interpreted in terms of the recently developed model [J. Chem. Phys. 85, 3615 (1986)] for electronic charge exchange in keV ion/surface collisions which considers electron promotions in the close atomic encounter and resonant and Auger transitions along the outgoing trajectory. The ionization potential of the primary ion relative to the energy levels of the target atom is shown to have a large influence on charge exchange in the close encounter. The ratio of direct recoil to scattering particle flux increases by a factor of >102 from He to Xe; scattering and recoil cross sections are used to model this process.

  2. Stereotactic Irradiation of GH-Secreting Pituitary Adenomas

    PubMed Central

    Minniti, G.; Scaringi, C.; Amelio, D.; Maurizi Enrici, R.

    2012-01-01

    Radiotherapy (RT) is often employed in patients with acromegaly refractory to medical and/or surgical interventions in order to prevent tumour regrowth and normalize elevated GH and IGF-I levels. It achieves tumour control and hormone normalization up to 90% and 70% of patients at 10–15 years. Despite the excellent tumour control, conventional RT is associated with a potential risk of developing late toxicity, especially hypopituitarism, and its role in the management of patients with GH-secreting pituitary adenomas remains a matter of debate. Stereotactic techniques have been developed with the aim to deliver more localized irradiation and minimize the long-term consequences of treatment, while improving its efficacy. Stereotactic irradiation can be given in a single dose as stereotactic radiosurgery (SRS) or in multiple doses as fractionated stereotactic radiotherapy (FSRT). We have reviewed the recent published literature on stereotactic techniques for GH-secreting pituitary tumors with the aim to define the efficacy and potential adverse effects of each of these techniques. PMID:22518123

  3. Size-fractionated dissolved primary production and carbohydrate composition of the coccolithophore Emiliania huxleyi

    NASA Astrophysics Data System (ADS)

    Borchard, C.; Engel, A.

    2014-11-01

    Extracellular release (ER) by phytoplankton is the major source of fresh dissolved organic carbon (DOC) in marine ecosystems and accompanies primary production during all growth phases. Little is known, so far, on size and composition of released molecules, and to which extent ER occurs passively, by leakage, or actively, by exudation. Here, we report on ER by the widespread and bloom-forming coccolithophore Emiliania huxleyi grown under steady state conditions in phosphorus controlled chemostats (N : P = 29, growth rate of μ = 0.2 d-1). 14C incubations were accomplished to determine primary production (PP), comprised by particulate (PO14C) and dissolved organic carbon (DO14C), and the concentration and composition of particulate combined carbohydrates (pCCHO), and of high molecular weight (>1 kDa, HMW) dissolved combined carbohydrates (dCCHO) as major components of ER. Information on size distribution of ER products was obtained by investigating distinct size classes (<0.40 μm, <1000 kDa, <100 kDa and <10 kDa) of DO14C and HMW-dCCHO. Our results revealed relatively low ER during steady state growth, corresponding to ∼4.5% of primary production, and similar ER rates for all size classes. Acidic sugars had a significant share on freshly produced pCCHO as well as on HMW-dCCHO. While pCCHO and the smallest size (<10 kDa) fraction of HMW-dCCHO exhibited a similar sugar composition, dominated by high percentages of glucose (74-80 Mol%), the composition of HMW-dCCHO size-classes >10 kDa was significantly different with higher Mol% of arabinose. Mol% of acidic sugars increased and Mol% glucose decreased with increasing size of HMW-dCCHO. We conclude that larger polysaccharides follow different production and release pathways than smaller molecules, potentially serving distinct ecological and biogeochemical functions.

  4. The role of stereotactic radiosurgery in the multimodal management of growth hormone-secreting pituitary adenomas.

    PubMed

    Stapleton, Christopher J; Liu, Charles Y; Weiss, Martin H

    2010-10-01

    Growth hormone (GH)-secreting pituitary adenomas represent a common source of GH excess in patients with acromegaly. Whereas surgical extirpation of the culprit lesion is considered first-line treatment, as many as 19% of patients develop recurrent symptoms due to regrowth of previously resected adenomatous tissue or to continued growth of the surgically inaccessible tumor. Although medical therapies that suppress GH production can be effective in the management of primary and recurrent acromegaly, these therapies are not curative, and lifelong treatment is required for hormonal control. Stereotactic radiosurgery has emerged as an effective adjunctive treatment modality, and is an appealing alternative to conventional fractionated radiation therapy. The authors reviewed the growing body of literature concerning the role of radiosurgical procedures in the treatment armamentarium of acromegaly, and identified more than 1350 patients across 45 case series. In this review, the authors report that radiosurgery offers true hormonal normalization in 17% to 82% of patients and tumor growth control in 37% to 100% of cases across all series, while minimizing adverse complications. As a result, stereotactic radiosurgery represents a safe and effective treatment option in the multimodal management of primary or recurrent acromegaly secondary to GH-secreting pituitary adenomas.

  5. Tomotherapy and stereotactic radiosurgery

    NASA Astrophysics Data System (ADS)

    Soisson, Emilie T.

    Currently, at the University of Wisconsin-Madison, a linear accelerator equipped with circular collimators and a floor stand is used for stereotactic radiosurgery (SRS) delivery. In the interest of providing a more efficient delivery option for patients with multiple brain metastases, a Tomotherapy-based radiosurgery program was developed to serve as an intensity modulated compliment to our existing delivery method. The unique advantage of Tomotherapy over other radiotherapy delivery units is the on board megavoltage CT that can be used for both stereotactic localization and treatment planning. As such, a workflow was designed in which the planning image is acquired on the treatment unit itself and, instead using a patient-frame based coordinate system for stereotactic localization, volumetric imaging is used to precisely locate the target at the time of treatment. Localization and delivery accuracy was found to be comparable to conventional approaches and well within stated tolerances. A Tomotherapy-specific treatment planning technique was also developed using the Tomotherapy treatment planning system that reliably produces plans that achieve both conformal target coverage and sufficiently steep dose falloff into surrounding normal brain. Tomotherapy plans have been compared to conventional circular collimator based plans for both the treatment of brain metastases and arteriovenous malformations in terms of both target conformity and dose to normal brain. To determine the effect of plan differences on patient outcome, clinical data was used to predict the resulting risk of treatment induced symptomatic brain necrosis for both conventional and Tomotherapy based plans. Overall, it was determined that plans generated using the described planning technique are acceptable for radiosurgery. In addition, delivery time for complex cases is comparable to or improved over conventional isocentric approaches. Finally, this work explores the impact of future product

  6. Stereotactic radiosurgery: comparing different technologies

    PubMed Central

    Schwartz, M

    1998-01-01

    Radiosurgery can be defined as 3-dimensional stereotactic irradiation of small intracranial targets by various radiation techniques. The goal is to deliver, with great accuracy, a large, single fraction dose to a small intracranial target, while minimizing the absorbed dose in the surrounding tissue. This article describes certain technical aspects of radiosurgery and compares the different methods of performing such treatment. The 2 most frequently used types of devices for radiosurgery are units with multiple cobalt sources (e.g., the Gamma Knife) and those based on a linear accelerator. In the former, highly collimated beams of radiation from the cobalt sources intersect at the target. In the latter, the source of a highly collimated beam of high-energy photons directed at the target turns through an arc or set of arcs. The accuracy of target localization, the steepness of fall-off of the radiation dose outside the target and the ability to irradiate an irregularly shaped target are all comparable for these 2 types of devices, despite claims to the contrary. PMID:9526480

  7. Stereotactic radiation therapy for hepatic malignancies.

    PubMed

    Meyer, Jeffrey

    2016-12-01

    Management of primary and secondary tumors of the liver is a complex undertaking involving multi‑disciplinary input. Radiation therapy has played a relatively marginal role in the treatment of liver tumors, but with technological innovations and the growth of the field of stereotactic body radiation therapy (SBRT), this role is evolving. In this review, I discuss the issues of radiation‑induced hepatic toxicity, the planning of liver SBRT treatments, clinical results with SBRT, its place amongst other non‑surgical ablative treatments, and potential future avenues of investigation.

  8. Size-fractionated dissolved primary production and carbohydrate composition of the coccolithophore Emiliania huxleyi

    NASA Astrophysics Data System (ADS)

    Borchard, C.; Engel, A.

    2015-02-01

    Extracellular release (ER) by phytoplankton is the major source of fresh dissolved organic carbon (DOC) in marine ecosystems and accompanies primary production during all growth phases. Little is known, so far, on size and composition of released molecules, and to which extent ER occurs passively, by leakage, or actively, by exudation. Here, we report on ER by the widespread and bloom-forming coccolithophore Emiliania huxleyi grown under steady-state conditions in phosphorus-controlled chemostats (N:P = 29, growth rate of μ = 0.2 d-1) at present-day and high-CO2 concentrations. 14C incubations were performed to determine primary production (PP), comprised of particulate (PO14C) and dissolved organic carbon (DO14C). Concentration and composition of particulate combined carbohydrates (pCCHO) and high-molecular-weight (>1 kDa, HMW) dissolved combined carbohydrates (dCCHO) were determined by ion chromatography. Information on size distribution of ER products was obtained by investigating distinct size classes (<0.4 μm (DO14C), <0.45 μm (HMW-dCCHO), <1000, <100 and <10 kDa) of DO14CC and HMW-dCCHO. Our results revealed relatively low ER during steady-state growth, corresponding to ~4.5% of primary production, and similar ER rates for all size classes. Acidic sugars had a significant share on freshly produced pCCHO as well as on HMW-dCCHO. While pCCHO and the smallest size fraction (<10 kDa) of HMW-dCCHO exhibited a similar sugar composition, dominated by high percentage of glucose (74-80 mol%), the composition of HMW-dCCHO size classes >10 kDa was significantly different, with a higher mol% of arabinose. The mol% of acidic sugars increased and that of glucose decreased with increasing size of HMW-dCCHO. We conclude that larger polysaccharides follow different production and release pathways than smaller molecules, potentially serving distinct ecological and biogeochemical functions.

  9. The Clinical Outcome of Hypofractionated Stereotactic Radiotherapy With CyberKnife Robotic Radiosurgery for Perioptic Pituitary Adenoma.

    PubMed

    Puataweepong, Putipun; Dhanachai, Mantana; Hansasuta, Ake; Dangprasert, Somjai; Swangsilpa, Thiti; Sitathanee, Chomporn; Jiarpinitnun, Chuleeporn; Vitoonpanich, Patamintita; Yongvithisatid, Pornpan

    2016-12-01

    Stereotactic radiation technique including single fraction radiosurgery and conventional fractionated stereotactic radiotherapy is widely reported as an effective treatment of pituitary adenomas. Because of the restricted radiation tolerance dose of the optic pathway, single fraction radiosurgery has been accepted for small tumor located far away from the optic apparatus, while fractionated stereotactic radiotherapy may be suitable for larger tumor located close to the optic pathway. More recently, hypofractionated stereotactic radiotherapy has become an alternative treatment option that provides high rate of tumor control and visual preservation for the perioptic lesions within 2 to 3 mm of the optic pathway. The objective of the study was to analyze the clinical outcomes of perioptic pituitary adenomas treated with hypofractionated stereotactic radiotherapy. From 2009 to 2012, 40 patients with perioptic pituitary adenoma were treated with CyberKnife robotic radiosurgery. The median tumor volume was 3.35 cm(3) (range, 0.82-25.86 cm(3)). The median prescribed dose was 25 Gy (range, 20-28 Gy) in 5 fractions (range, 3-5). After the median follow-up time of 38.5 months (range, 14-71 months), 1 (2.5%) patient with prolactinoma had tumor enlargement, 31 (77.5%) were stable, and the remaining 8 (20%) tumors were smaller in size. No patient's vision deteriorated after hypofractionated stereotactic radiotherapy. Hormone normalization was observed in 7 (54%) of 13 patients. No newly developed hypopituitarism was detected in our study. These data confirmed that hypofractionated stereotactic radiotherapy achieved high rates of tumor control and visual preservation. Because of the shorter duration of treatment, it may be preferable to use hypofractionated stereotactic radiotherapy over fractionated stereotactic radiotherapy for selected pituitary adenomas immediately adjacent to the optic apparatus.

  10. Stereotactic Radiotherapy for Adrenal Gland Metastases: University of Florence Experience

    SciTech Connect

    Casamassima, Franco; Livi, Lorenzo; Masciullo, Stefano; Menichelli, Claudia; Masi, Laura; Meattini, Icro; Bonucci, Ivano; Agresti, Benedetta; Simontacchi, Gabriele; Doro, Raffaela

    2012-02-01

    Purpose: To evaluate a retrospective single-institution outcome after hypofractionated stereotactic body radiotherapy (SBRT) for adrenal metastases. Methods and Materials: Between February 2002 and December 2009, we treated 48 patients with SBRT for adrenal metastases. The median age of the patient population was 62.7 years (range, 43-77 years). In the majority of patients, the prescription dose was 36 Gy in 3 fractions (70% isodose, 17.14 Gy per fraction at the isocenter). Eight patients were treated with single-fraction stereotactic radiosurgery and forty patients with multi-fraction stereotactic radiotherapy. Results: Overall, the series of patients was followed up for a median of 16.2 months (range, 3-63 months). At the time of analysis, 20 patients were alive and 28 patients were dead. The 1- and 2-year actuarial overall survival rates were 39.7% and 14.5%, respectively. We recorded 48 distant failures and 2 local failures, with a median interval to local failure of 4.9 months. The actuarial 1-year disease control rate was 9%; the actuarial 1- and 2-year local control rate was 90%. Conclusion: Our retrospective study indicated that SBRT for the treatment of adrenal metastases represents a safe and effective option with a control rate of 90% at 2 years.

  11. Stereotactic Body Radiotherapy for Treatment of Adrenal Metastases

    SciTech Connect

    Chawla, Sheema; Chen, Yuhchyau; Katz, Alan W.; Muhs, Ann G.; Philip, Abraham; Okunieff, Paul; Milano, Michael T.

    2009-09-01

    Purpose: To investigate the dosimetry and outcomes of patients undergoing stereotactic body radiotherapy (SBRT) for metastases to the adrenal glands. Methods and Materials: At University of Rochester, patients have been undergoing SBRT for limited metastases since 2001. We retrospectively reviewed 30 patients who had undergone SBRT for adrenal metastases from various primary sites, including lung (n = 20), liver (n = 3), breast (n = 3), melanoma (n = 1), pancreas (n = 1), head and neck (n = 1), and unknown primary (n = 1). Results: Of the 30 patients, 14 with five or fewer metastatic lesions (including adrenal) underwent SBRT, with the intent of controlling all known sites of metastatic disease, and 16 underwent SBRT for palliation or prophylactic palliation of bulky adrenal metastases. The prescribed dose ranged from 16 Gy in 4 fractions to 50 Gy in 10 fractions. The median dose was 40 Gy. Of the 30 patients, 24 had >3 months of follow-up with serial computed tomography. Of these 24 patients, 1 achieved a complete response, 15 achieved a partial response, 4 had stable disease, and 4 developed progressive disease. No patient developed symptomatic progression of their adrenal metastases. The 1-year survival, local control, and distant control rate was 44%, 55%, and 13%, respectively. No patient developed Radiation Therapy Oncology Group Grade 2 or greater toxicity. Conclusion: SBRT for adrenal metastases is well tolerated. Most patients developed widespread metastases shortly after treatment. Local control was poor, although this was a patient population selected for adverse risk factors, such as bulky disease. Additional studies are needed to determine the efficacy of SBRT for oligometastatic adrenal metastases, given the propensity of these patients to develop further disease progression.

  12. TU-F-BRE-07: In Vivo Neutron Detection in Patients Undergoing Stereotactic Ablative Radiotherapy (SABR) for Primary Kidney Cancer Using 6Li and 7Li Enriched TLD Pairs

    SciTech Connect

    Lonski, P; Kron, T; Franich, R; Keehan, S; Siva, S; Taylor, M

    2014-06-15

    Purpose: Stereotactic ablative radiotherapy (SABR) for primary kidney cancer often involves the use of high-energy photons combined with a large number of monitor units. While important for risk assessment, the additional neutron dose to untargeted healthy tissue is not accounted for in treatment planning. This work aims to detect out-of-field neutrons in vivo for patients undergoing SABR with high-energy (>10 MV) photons and provides preliminary estimates of neutron effective dose. Methods: 3 variations of high-sensitivity LiF:Mg,Cu,P thermoluminescent dosimeter (TLD) material, each with varying {sup 6}Li / {sup 7}Li concentrations, were used in custom-made Perspex holders for in vivo measurements. The variation in cross section for thermal neutrons between Li isotopes was exploited to distinguish neutron from photon signal. Measurements were made out-of-field for 7 patients, each undergoing 3D-conformal SABR treatment for primary kidney cancer on a Varian 21iX linear accelerator. Results: In vivo measurements show increased signal for the {sup 6}Li enriched material for patients treated with 18 MV photons. Measurements on one SABR patient treated using only 6 MV showed no difference between the 3 TLD materials. The out-of-field photon signal decreased exponentially with distance from the treatment field. The neutron signal, taken as the difference between {sup 6}Li enriched and {sup 7}Li enriched TLD response, remains almost constant up to 50 cm from the beam central axis. Estimates of neutron effective dose from preliminary TLD calibration suggest between 10 and 30 mSv per 1000 MU delivered at 18 MV for the 7 patients. Conclusion: TLD was proven to be a useful tool for the purpose of in vivo neutron detection at out-of-field locations. Further work is required to understand the relationship between TL signal and neutron dose. Dose estimates based on preliminary TLD calibration in a neutron beam suggest the additional neutron dose was <30 mSv per 1000 MU at 18 MV.

  13. Three-Staged Stereotactic Radiotherapy Without Whole Brain Irradiation for Large Metastatic Brain Tumors

    SciTech Connect

    Higuchi, Yoshinori Serizawa, Toru; Nagano, Osamu; Matsuda, Shinji; Ono, Junichi; Sato, Makoto; Iwadate, Yasuo; Saeki, Naokatsu

    2009-08-01

    Purpose: To evaluate the efficacy and toxicity of staged stereotactic radiotherapy with a 2-week interfraction interval for unresectable brain metastases more than 10 cm{sup 3} in volume. Patients and Methods: Subjects included 43 patients (24 men and 19 women), ranging in age from 41 to 84 years, who had large brain metastases (> 10 cc in volume). Primary tumors were in the colon in 14 patients, lung in 12, breast in 11, and other in 6. The peripheral dose was 10 Gy in three fractions. The interval between fractions was 2 weeks. The mean tumor volume before treatment was 17.6 {+-} 6.3 cm{sup 3} (mean {+-} SD). Mean follow-up interval was 7.8 months. The local tumor control rate, as well as overall, neurological, and qualitative survivals, were calculated using the Kaplan-Meier method. Results: At the time of the second and third fractions, mean tumor volumes were 14.3 {+-} 6.5 (18.8% reduction) and 10.6 {+-} 6.1 cm{sup 3} (39.8% reduction), respectively, showing significant reductions. The median overall survival period was 8.8 months. Neurological and qualitative survivals at 12 months were 81.8% and 76.2%, respectively. Local tumor control rates were 89.8% and 75.9% at 6 and 12 months, respectively. Tumor recurrence-free and symptomatic edema-free rates at 12 months were 80.7% and 84.4%, respectively. Conclusions: The 2-week interval allowed significant reduction of the treatment volume. Our results suggest staged stereotactic radiotherapy using our protocol to be a possible alternative for treating large brain metastases.

  14. MO-B-18C-01: Proton Therapy II: Proton Stereotactic Radiotherapy

    SciTech Connect

    Winey, B; Daartz, J

    2014-06-15

    Proton stereotactic radiotherapy shares fundamental principles with general proton therapy physics, specifically range uncertainties and broad beam measurement techniques. Significant differences emerge when treating with smaller field sizes that suffer lateral disequilibrium and when fractions are reduced. This session will explore the history and scope of proton stereotactic radiotherapy in clinical practice. Uncertainties and treatment planning methods specific to stereotactic treatments will be discussed. The session will include an overview of the physical properties of small proton fields and resulting needs for accurate measurements and modeling of dose distributions for radiosurgery treatment planning. Learning Objectives: Understand the clinical rationale for proton radiosurgery. Understand the similarities and differences from general proton therapy. Understand the similarities and differences from photon stereotactic radiosurgery. Understand the basic physics and clinical physics methods for measuring and commissioning a radiosurgery program.

  15. Image-Guided Robotic Stereotactic Body Radiation Therapy for Liver Metastases: Is There a Dose Response Relationship?

    SciTech Connect

    Vautravers-Dewas, Claire; Dewas, Sylvain; Bonodeau, Francois; Adenis, Antoine; Lacornerie, Thomas; Penel, Nicolas; Lartigau, Eric; Mirabel, Xavier

    2011-11-01

    Purpose: To evaluate the outcome, tolerance, and toxicity of stereotactic body radiotherapy, using image-guided robotic radiation delivery, for the treatment of patients with unresectable liver metastases. Methods and Material: Patients were treated with real-time respiratory tracking between July 2007 and April 2009. Their records were retrospectively reviewed. Metastases from colorectal carcinoma and other primaries were not necessarily confined to liver. Toxicity was evaluated using National Cancer Institute Common Criteria for Adverse Events version 3.0. Results: Forty-two patients with 62 metastases were treated with two dose levels of 40 Gy in four Dose per Fraction (23) and 45 Gy in three Dose per Fraction (13). Median follow-up was 14.3 months (range, 3-23 months). Actuarial local control for 1 and 2 years was 90% and 86%, respectively. At last follow-up, 41 (66%) complete responses and eight (13%) partial responses were observed. Five lesions were stable. Nine lesions (13%) were locally progressed. Overall survival was 94% at 1 year and 48% at 2 years. The most common toxicity was Grade 1 or 2 nausea. One patient experienced Grade 3 epidermitis. The dose level did not significantly contribute to the outcome, toxicity, or survival. Conclusion: Image-guided robotic stereotactic body radiation therapy is feasible, safe, and effective, with encouraging local control. It provides a strong alternative for patients who cannot undergo surgery.

  16. [Stereotactic body radiation therapy for spinal metastases].

    PubMed

    Pasquier, D; Martinage, G; Mirabel, X; Lacornerie, T; Makhloufi, S; Faivre, J-C; Thureau, S; Lartigau, É

    2016-10-01

    After the liver and lungs, bones are the third most common sites of cancer metastasis. Palliative radiotherapy for secondary bone tumours helps relieve pain, improve the quality of life and reduce the risk of fractures. Stereotactic body radiotherapy can deliver high radiation doses with very tight margins, which has significant advantages when treating tumours close to the spinal cord. Strict quality control is essential as dose gradient at the edge of the spinal cord is important. Optimal schedule is not defined. A range of dose-fractionation schedules have been used. Pain relief and local control are seen in over 80%. Toxicity rates are low, although vertebral fracture may occur. Ongoing prospective studies will help clarify its role in the management of oligometastatic patients.

  17. NOTE: Scatter-to-primary based scatter fractions for transmission-dependent convolution subtraction of SPECT images

    NASA Astrophysics Data System (ADS)

    Larsson, Anne; Johansson, Lennart

    2003-11-01

    In single photon emission computed tomography (SPECT), transmission-dependent convolution subtraction has been shown to be useful when correcting for scattered events. The method is based on convolution subtraction, but includes a matrix of scatter fractions instead of a global scatter fraction. The method can be extended to iteratively improve the scatter estimate, but in this note we show that this requires a modification of the theory to use scatter-to-total scatter fractions for the first iteration only and scatter-to-primary fractions thereafter. To demonstrate this, scatter correction is performed on a Monte Carlo simulated image of a point source of activity in water. The modification of the theory is compared to corrections where the scatter fractions are based on the scatter-to-total ratio, using one and ten iterations. The resulting ratios of subtracted to original counts are compared to the true scatter-to-total ratio of the simulation and the most accurate result is found for our modification of the theory.

  18. Stereotactic diffusion tensor imaging tractography for Gamma Knife radiosurgery.

    PubMed

    Gavin, Cormac G; Ian Sabin, H

    2016-12-01

    OBJECTIVE The integration of modern neuroimaging into treatment planning has increased the therapeutic potential and safety of stereotactic radiosurgery. The authors report their method of integrating stereotactic diffusion tensor imaging (DTI) tractography into conventional treatment planning for Gamma Knife radiosurgery (GKRS). The aim of this study was to demonstrate the feasibility of this technique and to address some of the technical limitations of previously reported techniques. METHODS Twenty patients who underwent GKRS composed the study cohort. They consisted of 1 initial test case (a patient with a vestibular schwannoma), 5 patients with arteriovenous malformations, 9 patients with cerebral metastases, 1 patient with parasagittal meningioma, and 4 patients with vestibular schwannoma. DT images were obtained at the time of standard GKRS protocol MRI (T1 and T2 weighted) for treatment, with the patient's head secured by a Leksell stereotactic frame. All studies were performed using a 1.5-T magnet with a single-channel head coil. DTI was performed with diffusion gradients in 32 directions and coregistered with the volumetric T1-weighted study. DTI postprocessing by means of commercially available software allowed tensor computation and the creation of directionally encoded color-, apparent diffusion coefficient-, and fractional anisotropy-mapped sequences. In addition, the software allowed visualized critical tracts to be exported as a structural volume and integrated into GammaPlan as an "organ at risk" during shot planning. Combined images were transferred to GammaPlan and integrated into treatment planning. RESULTS Stereotactic DT images were successfully acquired in all patients, with generation of correct directionally encoded color images. Tract generation with the software was straightforward and reproducible, particularly for axial tracts such as the optic radiation and the arcuate fasciculus. Corticospinal tract visualization was hampered by some

  19. Stereotactic body radiation therapy for metastasis to the adrenal glands.

    PubMed

    Shiue, Kevin; Song, Andrew; Teh, Bin S; Ellis, Rodney J; Yao, Min; Mayr, Nina A; Huang, Zhibin; Sohn, Jason; Machtay, Mitchell; Lo, Simon S

    2012-12-01

    Many primary cancers can metastasize to the adrenal glands. Adrenalectomy via an open or laparoscopic approach is the current definitive treatment, but not all patients are eligible or wish to undergo surgery. There are only limited studies on the use of conventional radiation therapy for palliation of symptoms from adrenal metastasis. However, the advent of stereotactic body radiation therapy (SBRT) - also named stereotactic ablative radiotherapy for primary lung cancer, metastases to the lung, and metastases to the liver - have prompted some investigators to consider the use of SBRT for metastases to the adrenal glands. This review focuses on the emerging data on SBRT of metastasis to the adrenal glands, while also providing a brief discussion of the overall management of adrenal metastasis.

  20. Modelling in Primary School: Constructing Conceptual Models and Making Sense of Fractions

    ERIC Educational Resources Information Center

    Shahbari, Juhaina Awawdeh; Peled, Irit

    2017-01-01

    This article describes sixth-grade students' engagement in two model-eliciting activities offering students the opportunity to construct mathematical models. The findings show that students utilized their knowledge of fractions including conceptual and procedural knowledge in constructing mathematical models for the given situations. Some students…

  1. A Survey of Stereotactic Body Radiotherapy in Korea

    PubMed Central

    Bae, Sun Hyun; Kim, Mi-Sook; Jang, Won Il; Kay, Chul-Seung; Kim, Woochul; Kim, Eun Seog; Kim, Jin Ho; Kim, Jin Hee; Yang, Kwang Mo; Lee, Kyu Chan; Chang, A Ram; Jo, Sunmi

    2015-01-01

    Purpose The purpose of this study is to investigate the current status of stereotactic body radiotherapy (SBRT) in Korea. A nationwide survey was conducted by the Korean Stereotactic Radiosurgery Group of the Korean Society for Radiation Oncology (KROG 13-13). Materials and Methods SBRT was defined as radiotherapy with delivery of a high dose of radiation to an extracranial lesion in ≤ 4 fractions. A 16-questionnaire survey was sent by e-mail to the chief of radiation oncology at 85 institutions in June 2013. Results All institutions (100%) responded to this survey. Of these, 38 institutions (45%) have used SBRT and 47 institutions (55%) have not used SBRT. Regarding the treatment site, the lung (92%) and liver (76%) were the two most common sites. The most common schedules were 60 Gy/4 fractions for non-small cell lung cancer, 48 Gy/4 fractions for lung metastases, 60 Gy/3 fractions for hepatocellular carcinoma, and 45 Gy/3 fractions or 40 Gy/4 fractions for liver metastases. Four-dimensional computed tomography (CT) was the most common method for planning CT (74%). During planning CT, the most common method of immobilization was the use of an alpha cradle/vacuum-lock (42%). Conclusion Based on this survey, conduct of further prospective studies will be needed in order to determine the appropriate prescribed doses and to standardize the practice of SBRT. PMID:25578057

  2. Primary production and biovolume of various phototrophic plankton size fractions in three southeastern United States reservoirs

    SciTech Connect

    Tison, D.; Wilde, E.W.

    1981-04-01

    Plankton size classes of < 3 ..mu..m consisting largely of unicellular cyanobacteria accounted for 15 to 40% of the total primary production and generally represented < 5% of the total phototrophic plankton biovolume in three South Carolina reservoirs.

  3. Versatility of the Novalis system to deliver image-guided stereotactic body radiation therapy (SBRT) for various anatomical sites.

    PubMed

    Teh, Bin S; Paulino, Arnold C; Lu, Hsin H; Chiu, J Kam; Richardson, Susan; Chiang, Stephen; Amato, Robert; Butler, E Brian; Bloch, Charles

    2007-08-01

    Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) programs to treat brain tumors were implemented when we first acquired the Brainlab Novalis system in 2003. Two years later, we started an extra-cranial stereotactic radio-ablation or more appropriately a stereotactic body radiation therapy (SBRT) program using the Brainlab Novalis image-guided system at The Methodist Hospital in Houston, Texas. We hereby summarize our initial experience with this system in delivering image-guided SBRT to a total of 80 patients during our first year of clinical implementation, from February 2005 to January 2006. Over 100 lesions in more than 20 distinct anatomical sites were treated. These include all levels of spine from cervical, thoracic, lumbar, and sacral lesions. Spinal lesions encompass intramedullary, intradural, extradural, or osseous compartments. Also treated were lesions in other bony sites including orbit, clavicle, scapula, humerus, sternum, rib, femur, and pelvis (ilium, ischium, and pubis). Primary or metastatic lesions located in the head and neck, supraclavicular region, axilla, mediastinum, lung (both central and peripheral), abdominal wall, liver, kidney, para-aortic lymph nodes, prostate, and pelvis were also treated. In addition to primary radiotherapy, SBRT program using the Brainlab Novalis system allows re-irradiation for recurrence and "boost" after conventional treatment to various anatomical sites. Treating these sites safely and efficaciously requires knowledge in radiation tolerance, fraction size, total dose, biologically equivalent dose (BED), prior radiotherapy, detailed dose volume histograms (DVH) of normal tissues, and the radiosensitive/radioresistant nature of the tumor. Placement of radio-opaque markers (Visicoil, Radiomed) in anatomical sites not in close proximity to bony landmarks (e.g., kidney and liver) helps in measuring motion and providing image guidance during each treatment fraction. Tumor/organ motion

  4. Phase 1 Clinical Trial of Stereotactic Body Radiation Therapy Concomitant With Neoadjuvant Chemotherapy for Breast Cancer

    SciTech Connect

    Bondiau, Pierre-Yves; Courdi, Adel; Bahadoran, Phillipe; Chamorey, Emmanuel; Queille-Roussel, Catherine; Lallement, Michel; Birtwisle-Peyrottes, Isabelle; Chapellier, Claire; Pacquelet-Cheli, Sandrine; Ferrero, Jean-Marc

    2013-04-01

    Purpose: Stereotactic body radiation therapy (SBRT) allows stereotactic irradiation of thoracic tumors. It may have a real impact on patients who may not otherwise qualify for breast-conserving surgery. We conducted a phase 1 trial that tested 5 dose levels of SBRT concomitant with neoadjuvant chemotherapy (NACT) before to surgery. The purpose of the current dose escalation study was to determine the maximum tolerable dose of SBRT in the treatment of breast cancer. Methods and Materials: To define toxicity, we performed dermatologic examinations that included clinical examinations by 2 separate physicians and technical evaluations using colorimetry, dermoscopy, and skin ultrasonography. Dermatologic examinations were performed before NACT, 36 and 56 days after the beginning of NACT, and before surgery. Surgery was performed 4 to 8 weeks after the last chemotherapy session. Efficacy, the primary endpoint, was determined by the pathologic complete response (pCR) rate. Results: Maximum tolerable dose was not reached. Only 1 case of dose-limiting toxicity was reported (grade 3 dermatologic toxicity), and SBRT was overall well tolerated. The pCR rate was 36%, with none being observed at the first 2 dose levels, and the highest rate being obtained at dose level 3 (25.5 Gy delivered in 3 fractions). Furthermore, the breast-conserving surgery rate was up to 92% compared with an 8% total mastectomy rate. No surgical complications were reported. Conclusions: This study demonstrates that SBRT can be safely combined with NACT. Regarding the efficacy endpoints, this trial showed promising results in terms of pCR rate (36%) and breast-conserving rate (92%). The findings provide a strong rationale for extending the study into a phase 2 trial. In view of the absence of correlation between dose and pCR, and given that the data from dose level 3 met the statistical requirements, a dose of 25.5 Gy in 3 fractions should be used for the phase 2 trial.

  5. Image-Guidance for Stereotactic Body Radiation Therapy

    SciTech Connect

    Fuss, Martin . E-mail: fussm@ohsu.edu; Boda-Heggemann, Judit; Papanikolau, Nikos; Salter, Bill J.

    2007-07-01

    The term stereotactic body radiation therapy (SBRT) describes a recently introduced external beam radiation paradigm by which small lesions outside the brain are treated under stereotactic conditions, in a single or few fractions of high-dose radiation delivery. Similar to the treatment planning and delivery process for cranial radiosurgery, the emphasis is on sparing of adjacent normal tissues through the creation of steep dose gradients. Thus, advanced methods for assuring an accurate relationship between the target volume position and radiation beam geometry, immediately prior to radiation delivery, must be implemented. Such methods can employ imaging techniques such as planar (e.g., x-ray) or volumetric (e.g., computed tomography [CT]) approaches and are commonly summarized under the general term image-guided radiation therapy (IGRT). This review summarizes clinical experience with volumetric and ultrasound based image-guidance for SBRT. Additionally, challenges and potential limitations of pre-treatment image-guidance are presented and discussed.

  6. Phase 2 Multi-institutional Trial Evaluating Gemcitabine and Stereotactic Body Radiotherapy for Patients With Locally Advanced Unresectable Pancreatic Adenocarcinoma

    PubMed Central

    Herman, Joseph M; Chang, Daniel T; Goodman, Karyn A; Dholakia, Avani S; Raman, Siva P; Hacker-Prietz, Amy; Iacobuzio-Donahue, Christine A; Griffith, Mary E; Pawlik, Timothy M; Pai, Jonathan S; O'Reilly, Eileen; Fisher, George A; Wild, Aaron T; Rosati, Lauren M; Zheng, Lei; Wolfgang, Christopher L; Laheru, Daniel A; Columbo, Laurie A; Sugar, Elizabeth A; Koong, Albert C

    2015-01-01

    Background This phase 2 multi-institutional study was designed to determine whether gemcitabine (GEM) with fractionated stereotactic body radiotherapy (SBRT) results in acceptable late grade 2 to 4 gastrointestinal toxicity when compared with a prior trial of GEM with single-fraction SBRT in patients with locally advanced pancreatic cancer (LAPC). Methods A total of 49 patients with LAPC received up to 3 doses of GEM (1000 mg/m2) followed by a 1-week break and SBRT (33.0 gray [Gy] in 5 fractions). After SBRT, patients continued to receive GEM until disease progression or toxicity. Toxicity was assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0] and the Radiation Therapy Oncology Group radiation morbidity scoring criteria. Patients completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (QLQ-C30) and pancreatic cancer-specific QLQ-PAN26 module before SBRT and at 4 weeks and 4 months after SBRT. Results The median follow-up was 13.9 months (range, 3.9-45.2 months). The median age of the patients was 67 years and 84% had tumors of the pancreatic head. Rates of acute and late (primary endpoint) grade ≥2 gastritis, fistula, enteritis, or ulcer toxicities were 2% and 11%, respectively. QLQ-C30 global quality of life scores remained stable from baseline to after SBRT (67 at baseline, median change of 0 at both follow-ups; P>.05 for both). Patients reported a significant improvement in pancreatic pain (P = .001) 4 weeks after SBRT on the QLQ-PAN26 questionnaire. The median plasma carbohydrate antigen 19-9 (CA 19-9) level was reduced after SBRT (median time after SBRT, 4.2 weeks; 220 U/mL vs 62 U/mL [P<.001]). The median overall survival was 13.9 months (95% confidence interval, 10.2 months-16.7 months). Freedom from local disease progression at 1 year was 78%. Four patients (8%) underwent margin-negative and lymph node-negative surgical resections. Conclusions

  7. Cancer initiating-cells are enriched in the CA9 positive fraction of primary cervix cancer xenografts

    PubMed Central

    Marie-Egyptienne, Delphine Tamara; Chaudary, Naz; Kalliomäki, Tuula; Hedley, David William; Hill, Richard Peter

    2017-01-01

    Numerous studies have suggested that Cancer Initiating Cells (CIC) can be identified/enriched in cell populations obtained from solid tumors based on the expression of cell surface marker proteins. We used early passage primary cervix cancer xenografts to sort cells based on the expression of the intrinsic hypoxia marker Carbonic Anhydrase 9 (CA9) and tested their cancer initiation potential by limiting dilution assay. We demonstrated that CICs are significantly enriched in the CA9+ fraction in 5/6 models studied. Analyses of the expression of the stem cell markers Oct4, Notch1, Sca-1 & Bmi1 showed a trend toward an increase in the CA9+ populations, albeit not significant. We present evidence that enhanced autophagy does not play a role in the enhanced growth of the CA9+ cells. Our study suggests a direct in vivo functional link between hypoxic cells and CICs in primary cervix cancer xenografts. PMID:27901496

  8. Clinical outcomes of stereotactic body radiotherapy for spinal metastases from hepatocellular carcinoma

    PubMed Central

    Lee, Eonju; Kim, Tae Gyu; Yu, Jeong Il; Lim, Do Hoon; Nam, Heerim; Lee, Hyebin; Lee, Joon Hyeok

    2015-01-01

    Purpose To investigate the outcomes of patients with spinal metastases from hepatocellular carcinoma (HCC), who were treated by stereotactic body radiotherapy (SBRT). Materials and Methods This retrospective study evaluated 23 patients who underwent SBRT from October 2008 to August 2012 for 36 spinal metastases from HCC. SBRT consisted of approximately 2 fractionation schedules, which were 18 to 40 Gy in 1 to 4 fractions for group A lesions (n = 15) and 50 Gy in 10 fractions for group B lesions (n = 21). Results The median follow-up period was 7 months (range, 2 to 16 months). Seven patients developed grade 1 or 2 gastrointestinal toxicity, and one developed grade 2 leucopenia. Compression fractures occurred in association with 25% of the lesions, with a median time to fracture of 2 months. Pain relief occurred in 92.3% and 68.4% of group A and B lesions, respectively. Radiologic response (complete and partial response) occurred in 80.0% and 61.9% of group A and B lesions, respectively. The estimated 1-year spinal-tumor progression-free survival rate was 78.5%. The median overall survival period and 1-year overall survival rate were 9 months (range, 2 to 16 months) and 25.7%, respectively. Conclusion SBRT for spinal metastases from HCC is well tolerated and effective at providing pain relief and radiologic response. Because compression fractures develop at a high rate following SBRT for spinal metastases from primary HCC, careful follow up of the patient is required. PMID:26484305

  9. Spinal Cord Tolerance for Stereotactic Body Radiotherapy

    SciTech Connect

    Sahgal, Arjun; Ma Lijun; Gibbs, Iris; Gerszten, Peter C.; Ryu, Sam; Soltys, Scott; Weinberg, Vivian; Wong Shun; Chang, Eric; Fowler, Jack; Larson, David A.

    2010-06-01

    Purpose: Dosimetric data are reported for five cases of radiation-induced myelopathy after stereotactic body radiotherapy (SBRT) to spinal tumors. Analysis per the biologically effective dose (BED) model was performed. Methods and Materials: Five patients with radiation myelopathy were compared to a subset of 19 patients with no radiation myelopathy post-SBRT. In all patients, the thecal sac was contoured to represent the spinal cord, and doses to the maximum point, 0.1-, 1-, 2-, and 5-cc volumes, were analyzed. The mean normalized 2-Gy-equivalent BEDs (nBEDs), calculated using an alpha/beta value of 2 for late toxicity with units Gy 2/2, were compared using the t test and analysis of variance test. Results: Radiation myelopathy was observed at the maximum point with doses of 25.6 Gy in two fractions, 30.9 Gy in three fractions, and 14.8, 13.1, and 10.6 Gy in one fraction. Overall, there was a significant interaction between patient subsets and volume based on the nBED (p = 0.0003). Given individual volumes, a significant difference was observed for the mean maximum point nBED (p = 0.01). Conclusions: The maximum point dose should be respected for spine SBRT. For single-fraction SBRT 10 Gy to a maximum point is safe, and up to five fractions an nBED of 30 to 35 Gy 2/2 to the thecal sac also poses a low risk of radiation myelopathy.

  10. Effect of boar seminal immunosuppressive fraction on B lymphocytes and on primary antibody response.

    PubMed

    Veselský, L; Dostál, J; Holán, V; Soucek, J; Zelezná, B

    1996-07-01

    Repeated i.p. or rectal treatment of male and female mice with an immunosuppressive component isolated from boar seminal vesicle secretion reduced responses of B lymphocytes to mitogen as evaluated by [3H]thymidine or bromo-deoxyuridine incorporation. The proliferative activity of T lymphocytes was not affected. By means of the immunofluorescence method, the seminal immunosuppressive component was detected on the membranes of B lymphocytes separated from the spleens of mice treated in vivo with immunosuppressor. An i.p. injection or rectal infusion of the immunosuppressive component also led to a suppression of primary antibody response to soluble and particulate antigens. These findings indicate that in vivo deposition of semen may compromise some aspects of the immune system and may be an important cofactor in the development of viral and bacterial infections in homosexual men.

  11. Robotic-arm stereotactic radiosurgery as a definitive treatment for gelastic epilepsy associated with hypothalamic hamartoma.

    PubMed

    Susheela, Sridhar Papaiah; Revannasiddaiah, Swaroop; Mallarajapatna, Govindarajan J; Basavalingaiah, Ajaikumar

    2013-09-11

    Gelastic seizures, characterised by paroxysms of pathological laughter, are most often associated with an underlying hypothalamic hamartoma. This report describes the definitive treatment using stereotactic-radiosurgery for a teenaged child whose gelastic epilepsy was found refractory to various antiepileptic drugs. Since surgery was not consented to, the child was referred to us for stereotactic radiosurgery (SRS), which was delivered with robotic-arm -SRS to a dose of 30 Gy in five fractions in five consecutive days. A decrease in the frequency of seizures was noticeable as early as within a week, and at 12 months after the procedure, there has been a total cessation of seizures.

  12. Relevance of Biologically Equivalent Dose Values in Outcome Evaluation of Stereotactic Radiotherapy for Lung Nodules

    SciTech Connect

    Casamassima, Franco Masi, Laura; Bonucci, Ivano; Polli, Caterina; Menichelli, Claudia; Gulisano, Massimo; Pacini, Stefania; Aterini, Stefano; Cavedon, Carlo

    2008-05-01

    Purpose: Different biologically equivalent dose (BED) values associated with stereotactic radiotherapy (SRT) of patients with primary and metastatic pulmonary nodules were studied. The BED values were calculated for tumoral tissue and low {alpha}/{beta} ratio, assuming that better local response could be obtained by using stereotactic high-BED treatment. Methods and Materials: Fifty-eight patients with T1-T3 N0 non-small-cell lung cancer and 46 patients with metastatic lung nodules were treated with SRT. The BED was calculated for {alpha}/{beta} ratios of 3 and 10. Overall survival (OS) was assessed according to Kaplan-Meier and appraised as a function of three BED levels: low (30-50 Gy), medium (50-70 Gy), and high (70-98 Gy; {alpha}/{beta} = 10). Results: The OS rates for all 104 patients at 12, 24, and 36 months were 73%, 48.3%, and 35.8%, respectively. Local response greater than 50% for low, medium, and high BED values was observed in 54%, 47%, and 73%, respectively. In the high-BED treated group, OS rates at 12, 24, and 36 months (80.9%, 70%, and 53.6%, respectively) were significantly improved compared with low- (69%, 46.1%, and 30.7%, respectively) and medium-BED (67%, 28%, and 21%, respectively) treated patients. Results are also discussed in terms of BED calculated on {alpha}/{beta} 3 Gy characteristic of the microcapillary bed. No acute toxicity higher than Grade 1 was observed. Conclusions: Radioablation of pulmonary neoplastic nodules may be achieved with SRT delivered by using a high-dose fraction with high BED value.

  13. Stereotactic radiotherapy using Novalis for skull base metastases developing with cranial nerve symptoms.

    PubMed

    Mori, Yoshimasa; Hashizume, Chisa; Kobayashi, Tatsuya; Shibamoto, Yuta; Kosaki, Katsura; Nagai, Aiko

    2010-06-01

    Skull base metastases are challenging situations because they often involve critical structures such as cranial nerves. We evaluated the role of stereotactic radiotherapy (SRT) which can give high doses to the tumors sparing normal structures. We treated 11 cases of skull base metastases from other visceral carcinomas. They had neurological symptoms due to cranial nerve involvement including optic nerve (3 patients), oculomotor (3), trigeminal (6), abducens (1), facial (4), acoustic (1), and lower cranial nerves (1). The interval between the onset of cranial nerve symptoms and Novalis SRT was 1 week to 7 months. Eleven tumors of 8-112 ml in volume were treated by Novalis SRT with 30-50 Gy in 10-14 fractions. The tumors were covered by 90-95% isodose. Imaging and clinical follow-up has been obtained in all 11 patients for 5-36 months after SRT. Seven patients among 11 died from primary carcinoma or other visceral metastases 9-36 months after Novalis SRT. All 11 metastatic tumors were locally controlled until the end of the follow-up time or patient death, though retreatment for re-growth was done in 1 patient. In 10 of 11 patients, cranial nerve deficits were improved completely or partially. In some patients, the cranial nerve symptoms were relieved even during the period of fractionated SRT. Novalis SRT is thought to be safe and effective treatment for skull base metastases with involvement of cranial nerves and it may improve cranial nerve symptoms quickly.

  14. Stereotactic Body Radiation Therapy in Spinal Metastases

    SciTech Connect

    Ahmed, Kamran A.; Stauder, Michael C.; Miller, Robert C.; Bauer, Heather J.; Rose, Peter S.; Olivier, Kenneth R.; Brown, Paul D.; Brinkmann, Debra H.; Laack, Nadia N.

    2012-04-01

    Purpose: Based on reports of safety and efficacy, stereotactic body radiotherapy (SBRT) for treatment of malignant spinal tumors was initiated at our institution. We report prospective results of this population at Mayo Clinic. Materials and Methods: Between April 2008 and December 2010, 85 lesions in 66 patients were treated with SBRT for spinal metastases. Twenty-two lesions (25.8%) were treated for recurrence after prior radiotherapy (RT). The mean age of patients was 56.8 {+-} 13.4 years. Patients were treated to a median dose of 24 Gy (range, 10-40 Gy) in a median of three fractions (range, 1-5). Radiation was delivered with intensity-modulated radiotherapy (IMRT) and prescribed to cover 80% of the planning target volume (PTV) with organs at risk such as the spinal cord taking priority over PTV coverage. Results: Tumor sites included 48, 22, 12, and 3 in the thoracic, lumbar, cervical, and sacral spine, respectively. The mean actuarial survival at 12 months was 52.2%. A total of 7 patients had both local and marginal failure, 1 patient experienced marginal but not local failure, and 1 patient had local failure only. Actuarial local control at 1 year was 83.3% and 91.2% in patients with and without prior RT. The median dose delivered to patients who experienced local/marginal failure was 24 Gy (range, 18-30 Gy) in a median of three fractions (range, 1-5). No cases of Grade 4 toxicity were reported. In 1 of 2 patients experiencing Grade 3 toxicity, SBRT was given after previous radiation. Conclusion: The results indicate SBRT to be an effective measure to achieve local control in spinal metastases. Toxicity of treatment was rare, including those previously irradiated. Our results appear comparable to previous reports analyzing spine SBRT. Further research is needed to determine optimum dose and fractionation to further improve local control and prevent toxicity.

  15. Stereotactic hypothalamotomy for behaviour disorders

    PubMed Central

    Schvarcz, J. R.; Driollet, R.; Rios, E.; Betti, O.

    1972-01-01

    Posterior hypothalamotomy is a relatively simple stereotactic procedure. The radiological determination of the target and its physiological corroboration by electrical stimulation are accurate. The lesions have always been made in the site of maximum sympathetic response. In this respect, the cardiovascular changes (hypertension and tachycardia), which are always elicited from a more restricted area, are of particular importance. Depth recordings, however, have been less useful. Undesirable side-effects, if present, were mild and transitory. There was no postoperative intelligence deficit, at least with the standard tests. Images PMID:5035309

  16. Vertebral Compression Fracture (VCF) After Spine Stereotactic Body Radiation Therapy (SBRT): Analysis of Predictive Factors

    SciTech Connect

    Cunha, Marcelo V.R.; Al-Omair, Ameen; Atenafu, Eshetu G.; Masucci, Giuseppina Laura; Letourneau, Daniel; Korol, Renee; Yu, Eugene; Howard, Peter; Lochray, Fiona; Costa, Leodante B. da; Fehlings, Michael G.; Sahgal, Arjun

    2012-11-01

    Purpose: Vertebral compression fractures (VCFs) are increasingly observed after spine stereotactic body radiation therapy (SBRT). The aim of this study was to determine the risk of VCF after spine SBRT and identify clinical and dosimetric factors predictive for VCF. The analysis incorporated the recently described Spinal Instability Neoplastic Score (SINS) criteria. Methods and Materials: The primary endpoint of this study was the development of a de novo VCF (ie, new endplate fracture or collapse deformity) or fracture progression based on an existing fracture at the site of treatment after SBRT. We retrospectively scored 167 spinal segments in 90 patients treated with spine SBRT according to each of the 6 SINS criteria. We also evaluated the presence of paraspinal extension, prior radiation, various dosimetric parameters including dose per fraction ({>=}20 Gy vs <20 Gy), age, and histology. Results: The median follow-up was 7.4 months. We identified 19 fractures (11%): 12 de novo fractures (63%) and 7 cases of fracture progression (37%). The mean time to fracture after SBRT was 3.3 months (range, 0.5-21.6 months). The 1-year fracture-free probability was 87.3%. Multivariate analysis confirmed that alignment (P=.0003), lytic lesions (P=.007), lung (P=.03) and hepatocellular (P<.0001) primary histologies, and dose per fraction of 20 Gy or greater (P=.004) were significant predictors of VCF. Conclusions: The presence of kyphotic/scoliotic deformity and the presence of lytic tumor were the only predictive factors of VCF based on the original 6 SINS criteria. We also report that patients with lung and hepatocellular tumors and treatment with SBRT of 20 Gy or greater in a single fraction are at a higher risk of VCF.

  17. A Pilot Study of Hypofractionated Stereotactic Radiation Therapy and Sunitinib in Previously Irradiated Patients With Recurrent High-Grade Glioma

    SciTech Connect

    Wuthrick, Evan J.; Curran, Walter J.; Camphausen, Kevin; Lin, Alexander; Glass, Jon; Evans, James; Andrews, David W.; Axelrod, Rita; Shi, Wenyin; Werner-Wasik, Maria; Haacke, E. Mark; Hillman, Gilda G.; Dicker, Adam P.

    2014-10-01

    Purpose/Objective(s): Angiogenic blockade with irradiation may enhance the therapeutic ratio of radiation therapy (RT) through vascular normalization. We sought to determine the safety and toxicity profile of continuous daily-dosed sunitinib when combined with hypofractionated stereotactic RT (fSRT) for recurrent high-grade gliomas (rHGG). Methods and Materials: Eligible patients had malignant high-grade glioma that recurred or progressed after primary surgery and RT. All patients received a minimum of a 10-day course of fSRT, had World Health Organization performance status of 0 to 1, and a life expectancy of >3 months. During fSRT, sunitinib was administered at 37.5 mg daily. The primary endpoint was acute toxicity, and response was assessed via serial magnetic resonance imaging. Results: Eleven patients with rHGG were enrolled. The fSRT doses delivered ranged from 30 to 42 Gy in 2.5- to 3.75-Gy fractions. The median follow-up time was 40 months. Common acute toxicities included hematologic disorders, fatigue, hypertension, and elevated liver transaminases. Sunitinib and fSRT were well tolerated. One grade 4 mucositis toxicity occurred, and no grade 4 or 5 hypertensive events or intracerebral hemorrhages occurred. One patient had a nearly complete response, and 4 patients had stable disease for >9 months. Two patients (18%) remain alive and progression-free >3 years from enrollment. The 6-month progression-free survival was 45%. Conclusions: Sunitinib at a daily dose of 37.5 mg given concurrently with hypofractionated stereotactic reirradiation for rHGG yields acceptable toxicities and an encouraging 6-month progression-free survival.

  18. Principles of Stereotactic Electroencephalography in Epilepsy Surgery.

    PubMed

    Lhatoo, Samden; Lacuey, Nuria; Ryvlin, Philippe

    2016-12-01

    Stereotactic electroencephalography is a method for the invasive study for the human epileptic brain as a prelude to epilepsy surgery. The discipline of stereotactic electroencephalography is underpinned by an anatomo-electro-clinical analysis of epileptic seizures of focal origin and goes beyond simple stereotactic placement of depth electrodes. Stringent analysis of semiological and electrophysiological features is coupled with an understanding of this information in 3D anatomical space. Stereotactic electroencephalography offers significant advantages over subdural grid implantations, allowing pinpoint accuracy access to sulcal areas and deep brain structures, such as the insula, cingulate, basal and mesial brain regions, while associated with lower complication rates. Recent times have seen an exponential growth in stereotactic electroencephalography interest, driven in part by increasing complexity of typical epilepsy surgery patients in epilepsy surgery centers. Such patients are much more likely to be magnetic resonance imaging negative, or reoperations, or to have multifocal or widespread areas of cortical abnormalities. Herein, we discuss the advantages of stereotactic electroencephalography, principles of patient selection, implantation, and interpretation.

  19. New developments in intracranial stereotactic radiotherapy for metastases.

    PubMed

    Pinkham, M B; Whitfield, G A; Brada, M

    2015-05-01

    Brain metastases are common and the prognosis for patients with multiple brain metastases treated with whole brain radiotherapy is limited. As systemic disease control continues to improve, the expectations of radiotherapy for brain metastases are growing. Stereotactic radiosurgery (SRS) as a high precision localised irradiation given in a single fraction prolongs survival in patients with a single brain metastasis and functional independence in those with up to three brain metastases. SRS technology has become commonplace and is available in many radiation oncology and neurosurgery departments. With increasing use there is a need for appropriate patient selection, refinement of dose-fractionation and safe integration of SRS with other treatment modalities. We review the evidence for current practice and new developments in the field, with a specific focus on patient-relevant outcomes.

  20. Radiobiological modeling of two stereotactic body radiotherapy schedules in patients with stage I peripheral non-small cell lung cancer

    PubMed Central

    Huang, Bao-tian; Lin, Zhu; Lin, Pei-xian; Lu, Jia-yang; Chen, Chuang-zhen

    2016-01-01

    This study aims to compare the radiobiological response of two stereotactic body radiotherapy (SBRT) schedules for patients with stage I peripheral non-small cell lung cancer (NSCLC) using radiobiological modeling methods. Volumetric modulated arc therapy (VMAT)-based SBRT plans were designed using two dose schedules of 1 × 34 Gy (34 Gy in 1 fraction) and 4 × 12 Gy (48 Gy in 4 fractions) for 19 patients diagnosed with primary stage I NSCLC. Dose to the gross target volume (GTV), planning target volume (PTV), lung and chest wall (CW) were converted to biologically equivalent dose in 2 Gy fraction (EQD2) for comparison. Five different radiobiological models were employed to predict the tumor control probability (TCP) value. Three additional models were utilized to estimate the normal tissue complication probability (NTCP) value for the lung and the modified equivalent uniform dose (mEUD) value to the CW. Our result indicates that the 1 × 34 Gy dose schedule provided a higher EQD2 dose to the tumor, lung and CW. Radiobiological modeling revealed that the TCP value for the tumor, NTCP value for the lung and mEUD value for the CW were 7.4% (in absolute value), 7.2% (in absolute value) and 71.8% (in relative value) higher on average, respectively, using the 1 × 34 Gy dose schedule. PMID:27203739

  1. Phase II Study to Assess the Efficacy of Hypofractionated Stereotactic Radiotherapy in Patients With Large Cavernous Sinus Hemangiomas

    SciTech Connect

    Wang Xin; Liu Xiaoxia; Mei Guanghai; Dai Jiazhong; Pan Li; Wang Enmin

    2012-06-01

    Purpose: Cavernous sinus hemangioma is a rare vascular tumor. The direct microsurgical approach usually results in massive hemorrhage. Although radiosurgery plays an important role in managing cavernous sinus hemangiomas as a treatment alternative to microsurgery, the potential for increased toxicity with single-session treatment of large tumors is a concern. The purpose of this study was to assess the efficacy of hypofractionated stereotactic radiotherapy in patients with large cavernous sinus hemangiomas. Methods: Fourteen patients with large (volume >20 cm{sup 3}) cavernous sinus hemangiomas were enrolled in a prospective Phase II study between December 2007 and December 2010. The hypofractionated stereotactic radiotherapy dose was 21 Gy delivered in 3 fractions. Results: After a mean follow-up of 15 months (range, 6-36 months), the magnetic resonance images showed a mean of 77% tumor volume reduction (range, 44-99%). Among the 6 patients with cranial nerve impairments before hypofractionated stereotactic radiotherapy, 1 achieved symptomatic complete resolution and 5 had improvement. No radiotherapy-related complications were observed during follow-up. Conclusion: Our current experience, though preliminary, substantiates the role of hypofractionated stereotactic radiotherapy for large cavernous sinus hemangiomas. Although a longer and more extensive follow-up is needed, hypofractionated stereotactic radiotherapy of 21 Gy delivered in 3 fractions is effective in reducing the tumor volume without causing any new deficits and can be considered as a treatment modality for large cavernous sinus hemangiomas.

  2. Stereotactic Body Radiation Therapy for Patients With Lung Cancer Previously Treated With Thoracic Radiation

    SciTech Connect

    Kelly, Patrick; Balter, Peter A.; Rebueno, Neal; Sharp, Hadley J.; Liao Zhongxing; Komaki, Ritsuko; Chang, Joe Y.

    2010-12-01

    Purpose: Stereotactic body radiation therapy (SBRT) provides excellent local control with acceptable toxicity for patients with early-stage non-small cell lung cancer. However, the efficacy and safety of SBRT for patients previously given thoracic radiation therapy is not known. In this study, we retrospectively reviewed outcomes after SBRT for recurrent disease among patients previously given radiation therapy to the chest. Materials and Methods: A search of medical records for patients treated with SBRT to the thorax after prior fractionated radiation therapy to the chest at The University of Texas M. D. Anderson Cancer Center revealed 36 such cases. The median follow-up time after SBRT was 15 months. The endpoints analyzed were overall survival, local control, and the incidence and severity of treatment-related toxicity. Results: SBRT provided in-field local control for 92% of patients; at 2 years, the actuarial overall survival rate was 59%, and the actuarial progression-free survival rate was 26%, with the primary site of failure being intrathoracic relapse. Fifty percent of patients experienced worsening of dyspnea after SBRT, with 19% requiring oxygen supplementation; 30% of patients experienced chest wall pain and 8% Grade 3 esophagitis. No Grade 4 or 5 toxic effects were noted. Conclusions: SBRT can provide excellent in-field tumor control in patients who have received prior radiation therapy. Toxicity was significant but manageable. The high rate of intrathoracic failure indicates the need for further study to identify patients who would derive the most benefit from SBRT for this purpose.

  3. Linac-based stereotactic radiotherapy and radiosurgery in patients with meningioma

    PubMed Central

    2014-01-01

    Background It was our purpose to analyze long-term clinical outcome and to identify prognostic factors after Linac-based fractionated stereotactic radiotherapy (Linac-based FSRT) and stereotactic radiosurgery (SRS) in patients with intracranial meningiomas. Materials and methods Between 10/1995 and 03/2009, 297 patients with a median age of 59 years were treated with FSRT for intracranial meningioma. 50 patients had a Grade I meningioma, 20 patients had a Grade II meningioma, 12 patients suffered from a Grade III tumor, and in 215 cases no histology was obtained (Grade 0). Of the 297 patients, 144 underwent FSRT as their primary treatment and 158 underwent postoperative FSRT. 179 patients received normofractionated radiotherapy (nFSRT), 92 patients received hypofractionated FSRT (hFSRT) and 26 patients underwent SRS. Patients with nFSRT received a mean total dose of 57.31 ± 5.82 Gy, patients with hFSRT received a mean total dose of 37.6 ± 4.4 Gy and patients who underwent SRS received a mean total dose of 17.31 ± 2.58 Gy. Results Median follow-up was 35 months. Overall progression free survival (PFS) was 92.3% at 3 years, 87% at 5 years and 84.1% at 10 years. Patients with adjuvant radiotherapy showed significantly better PFS-rates than patients who had been treated with primary radiotherapy. There was no significant difference between PFS-rates of nFSRT, hFSRT and SRS patients. PFS-rates were independent of tumor size. Patients who had received nFSRT showed less acute toxicity than those who had received hFSRT. In the Grade 0/I group the rate of radiologic focal reactions was significantly lower than in the atypical/malignant histology group. Conclusion This large study showed that FSRT is an effective and safe treatment modality with high PFS-rates for intracranial meningioma. We identified “pathological grading” and and “prior surgery” as significant prognostic factors. PMID:24650090

  4. Stereotactic radiotherapy of meningiomas compressing optical pathways

    SciTech Connect

    Hamm, Klaus-Detlef . E-mail: khamm@erfurt.helios-kliniken.de; Henzel, Martin; Gross, Markus W.; Surber, Gunnar; Kleinert, Gabriele; Engenhart-Cabillic, Rita

    2006-11-15

    Purpose: Microsurgical resection is usually the treatment of choice for meningiomas, especially for those that compress the optical pathways. However, in many cases of skull-base meningiomas a high risk of neurological deficits and recurrences exist in cases where the complete tumor removal was not possible. In such cases (fractionated) stereotactic radiotherapy (SRT) can offer an alternative treatment option. We evaluated the local control rate, symptomatology, and toxicity. Patients and Methods: Between 1997 and 2003, 183 patients with skull-base meningiomas were treated with SRT, among them were 65 patients with meningiomas that compressed optical pathways (64 benign, 1 atypical). Of these 65 cases, 20 were treated with SRT only, 27 were subtotally resected before SRT, and 18 underwent multiple tumor resections before SRT. We investigated the results until 2005, with a median follow-up of 45 months (range, 22-83 months). The tumor volume (TV = gross tumor volume) ranged from 0.61 to 90.20 cc (mean, 18.9 cc). Because of the risk of new visual disturbances, the dose per fraction was either 2 or 1.8 Gy for all patients, to a total dose of 50 to 60 Gy. Results: The overall survival and the progression-free survival rates for 5 years were assessed to 100% in this patient group. To date, no progression for these meningiomas have been observed. Quantitatively, tumor shrinkage of more than 20%, or more than 2 mm in diameter, was proved in 35 of the 65 cases after SRT. In 29 of the 65 patients, at least 1 of the symptoms improved. On application of the Common Toxicity Criteria (CTC), acute toxicity (Grade 3) was seen in 1 case (worsening of conjunctivitis). Another 2 patients developed late toxicity by LENT-SOMA score, 1 x Grade 1 and 1 x Grade 3 (field of vision loss). Conclusion: As a low-risk and effective treatment option for tumor control, SRT with 1.8 to 2.0 Gy per fraction can also be recommended in case of meningiomas that compress optical pathways. An

  5. Gallotannin-rich Caesalpinia spinosa fraction decreases the primary tumor and factors associated with poor prognosis in a murine breast cancer model

    PubMed Central

    2013-01-01

    Background Several treatment alternatives are available for primary breast cancer, although those for metastatic disease or inflammation associated with tumor progression are ineffective. Therefore, there is a great need for new therapeutic alternatives capable of generating an immune response against residual tumor cells, thus contributing to eradication of micrometastases and cancer stem cells. The use of complex natural products is an excellent therapeutic alternative widely used by Chinese, Hindu, Egyptian, and ancestral Latin-American Indian populations. Methods The present study evaluated cytotoxic, antitumor, and tumor progression activities of a gallotannin-rich fraction derived from Caesalpinia spinosa (P2Et). The parameters evaluated in vitro were mitochondrial membrane depolarization, phosphatidylserine externalization, caspase 3 activation, DNA fragmentation, and clonogenic activity. The parameters evaluated in vivo were tumor growth, leukocyte number, metastatic cell number, and cytokine production by flow cytometry. Results The in vitro results showed that the P2Et fraction induced apoptosis with mitochondrial membrane potential loss, phosphatidylserine externalization, caspase 3 activation, DNA fragmentation, and decreased clonogenic capacity of 4T1 cells. In vivo, the P2Et fraction induced primary tumor reduction in terms of diameter and weight in BALB/c mice transplanted with 4T1 cells and decreased numbers of metastatic cells, mainly in the spleen. Furthermore, decreases in the number of peripheral blood leukocytes (leukemoid reaction) and interleukin 6 (IL-6) serum levels were found, which are events associated with a poor prognosis. The P2Et fraction exerts its activity on the primary tumor, reduces cell migration to distant organs, and decreases IL-6 serum levels, implying tumor microenvironment mechanisms. Conclusions Overall, the P2Et fraction lessens risk factors associated with tumor progression and diminishes primary tumor size, showing

  6. Stereotactic Body Radiation Therapy for Oligometastases to the Lung: A Phase 2 Study

    SciTech Connect

    Nuyttens, Joost J.; Voort van Zyp, Noëlle C.M.G. van der; Verhoef, Cornelis; Maat, A.; Klaveren, Robertus J. van; Holt, Bronno van der; Aerts, Joachim; Hoogeman, Mischa

    2015-02-01

    Purpose: To assess, in a phase 2 study, the efficacy and toxicity of stereotactic body radiation therapy for oligometastases to the lung in inoperable patients. Methods and Materials: Patients with lung metastases were included in this study if (1) the primary tumor was controlled; (2) patients were ineligible for or refused surgery and chemotherapy; and (3) patients had 5 or fewer metastatic lesions in no more than 2 organs. Large peripheral tumors were treated with a dose of 60 Gy (3 fractions), small peripheral tumors with 30 Gy (1 fraction), central tumors received 60 Gy (5 fractions), and mediastinal tumors or tumors close to the esophagus received 56 Gy (7 fractions). Results: Thirty patients with 57 metastatic lung tumors from various primary cancers were analyzed. The median follow-up was 36 months (range, 4-60 months). At 2 years, local control for the 11 central tumors was 100%, for the 23 peripheral tumors treated to 60 Gy it was 91%, and for the 23 tumors treated in a single 30-Gy fraction it was 74% (P=.13). This resulted in an overall local control rate at 1 year of 79%, with a 2-sided 80% confidence interval of 67% to 87%. Because the hypothesized value of 70% lies within the confidence interval, we cannot reject the hypothesis that the true local control rate at 1 year is ≤70%, and therefore we did not achieve the goal of the study: an actuarial local control of the treated lung lesions at 1 year of 90%. The 4-year overall survival rate was 38%. Grade 3 acute toxicity occurred in 5 patients. Three patients complained of chronic grade 3 toxicity, including pain, fatigue, and pneumonitis, and 3 patients had rib fractures. Conclusions: The local control was promising, and the 4-year overall survival rate was 38%. The treatment was well tolerated, even for central lesions.

  7. [Brain radiation necrosis after stereotactic radiotherapy of the resection cavity for intracranial metastases: analysis of the literature from four cases].

    PubMed

    Doré, M; Lefebvre, L; Delpon, G; Thillays, F

    2015-04-01

    Stereotactic hypofractionated radiotherapy after resection of brain metastasis is an alternative to whole brain radiotherapy. A high dose per fraction is associated with a risk of radiation necrosis. We present four cases of confirmed histological radiation necrosis. Differentiating recurrent tumour from radiation necrosis in this scenario is challenging. An enhancing area in magnetic resonance imaging (MRI) with a "cut bell pepper" appearance may suggest radiation necrosis. Advanced imaging modalities such as perfusion MR imaging and positron emission tomography can be useful. Dosimetric predictors of the occurrence of radiation necrosis after stereotactic hypofractionated radiotherapy are poorly understood and require prospective studies on larger cohorts.

  8. Robust frameless stereotactic localization in extra-cranial radiotherapy

    SciTech Connect

    Riboldi, Marco; Baroni, Guido; Spadea, Maria Francesca; Bassanini, Fabio; Tagaste, Barbara; Garibaldi, Cristina; Orecchia, Roberto; Pedotti, Antonio

    2006-04-15

    In the field of extra-cranial radiotherapy, several inaccuracies can make the application of frameless stereotactic localization techniques error-prone. When optical tracking systems based on surface fiducials are used, inter- and intra-fractional uncertainties in marker three-dimensional (3D) detection may lead to inexact tumor position estimation, resulting in erroneous patient setup. This is due to the fact that external fiducials misdetection results in deformation effects that are poorly handled in a rigid-body approach. In this work, the performance of two frameless stereotactic localization algorithms for 3D tumor position reconstruction in extra-cranial radiotherapy has been specifically tested. Two strategies, unweighted versus weighted, for stereotactic tumor localization were examined by exploiting data coming from 46 patients treated for extra-cranial lesions. Measured isocenter displacements and rotations were combined to define isocentric procedures, featuring 6 degrees of freedom, for correcting patient alignment (isocentric positioning correction). The sensitivity of the algorithms to uncertainties in the 3D localization of fiducials was investigated by means of 184 numerical simulations. The performance of the implemented isocentric positioning correction was compared to conventional point-based registration. The isocentric positioning correction algorithm was tested on a clinical dataset of inter-fractional and intra-fractional setup errors, which was collected by means of an optical tracker on the same group of patients. The weighted strategy exhibited a lower sensitivity to fiducial localization errors in simulated misalignments than those of the unweighted strategy. Isocenter 3D displacements provided by the weighted strategy were consistently smaller than those featured by the unweighted strategy. The peak decrease in median and quartile values of isocenter 3D displacements were 1.4 and 2.7 mm, respectively. Concerning clinical data, the

  9. Imaging of Radiation Dose for Stereotactic Radiosurgery

    SciTech Connect

    Guan, Timothy Y.; Almond, Peter R.; Park, Hwan C.; Lindberg, Robert D.; Shields, Christopher B.

    2015-01-15

    The distributions of radiation dose for stereotactic radiosurgery, using a modified linear accelerator (Philips SL-25 and SRS-200), have been studied by using three different dosimeters: (1) ferrous-agarose-xylenol orange (FAX) gels, (2) TLD, and (3) thick-emulsion GafChromic dye film. These dosimeters were loaded into a small volume of defect in a phantom head. A regular linac stereotactic radiosurgery treatment was then given to the phantom head for each type of dosimeter. The measured radiation dose and its distributions were found to be in good agreement with those calculated by the treatment planning computer.

  10. Normal tissue toxicity after small field hypofractionated stereotactic body radiation

    PubMed Central

    Milano, Michael T; Constine, Louis S; Okunieff, Paul

    2008-01-01

    Stereotactic body radiation (SBRT) is an emerging tool in radiation oncology in which the targeting accuracy is improved via the detection and processing of a three-dimensional coordinate system that is aligned to the target. With improved targeting accuracy, SBRT allows for the minimization of normal tissue volume exposed to high radiation dose as well as the escalation of fractional dose delivery. The goal of SBRT is to minimize toxicity while maximizing tumor control. This review will discuss the basic principles of SBRT, the radiobiology of hypofractionated radiation and the outcome from published clinical trials of SBRT, with a focus on late toxicity after SBRT. While clinical data has shown SBRT to be safe in most circumstances, more data is needed to refine the ideal dose-volume metrics. PMID:18976463

  11. Concurrent Stereotactic Radiosurgery and Bevacizumab in Recurrent Malignant Gliomas: A Prospective Trial

    SciTech Connect

    Cabrera, Alvin R.; Cuneo, Kyle C.; Desjardins, Annick; Sampson, John H.; McSherry, Frances; Herndon, James E.; Peters, Katherine B.; Allen, Karen; Hoang, Jenny K.; Chang, Zheng; Craciunescu, Oana; Vredenburgh, James J.; Friedman, Henry S.; Kirkpatrick, John P.

    2013-08-01

    Purpose: Virtually all patients with malignant glioma (MG) eventually recur. This study evaluates the safety of concurrent stereotactic radiosurgery (SRS) and bevacizumab (BVZ), an antiangiogenic agent, in treatment of recurrent MG. Methods and Materials: Fifteen patients with recurrent MG, treated at initial diagnosis with surgery and adjuvant radiation therapy/temozolomide and then at least 1 salvage chemotherapy regimen, were enrolled in this prospective trial. Lesions <3 cm in diameter were treated in a single fraction, whereas those 3 to 5 cm in diameter received 5 5-Gy fractions. BVZ was administered immediately before SRS and 2 weeks later. Neurocognitive testing (Mini-Mental Status Exam, Trail Making Test A/B), Functional Assessment of Cancer Therapy-Brain (FACT-Br) quality-of-life assessment, physical exam, and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) were performed immediately before SRS and 1 week and 2 months following completion of SRS. The primary endpoint was central nervous system (CNS) toxicity. Secondary endpoints included survival, quality of life, microvascular properties as measured by DCE-MRI, steroid usage, and performance status. Results: One grade 3 (severe headache) and 2 grade 2 CNS toxicities were observed. No patients experienced grade 4 to 5 toxicity or intracranial hemorrhage. Neurocognition, quality of life, and Karnofsky performance status did not change significantly with treatment. DCE-MRI results suggest a significant decline in tumor perfusion and permeability 1 week after SRS and further decline by 2 months. Conclusions: Treatment of recurrent MG with concurrent SRS and BVZ was not associated with excessive toxicity in this prospective trial. A randomized trial of concurrent SRS/BVZ versus conventional salvage therapy is needed to establish the efficacy of this approach.

  12. Stereotactic radiotherapy for spinal intradural metastases developing within or adjacent to the previous irradiation field--report of three cases.

    PubMed

    Mori, Yoshimasa; Hashizume, Chisa; Shibamoto, Yuta; Kobayashi, Tatsuya; Nakazawa, Hisato; Hagiwara, Masahiro; Tsugawa, Takahiko

    2013-08-01

    Results of stereotactic radiotherapy (SRT) for spinal intradural metastases developing inside or adjacent to the previous external-beam radiation therapy (EBRT) field are shown in 3 cases. One case of spinal intramedullary metastasis and two cases of intradural extramedullary metastases were treated using a Novalis shaped-beam SRT. Case 1 developed an intramedullary metastatic tumor in the C1 spinal medulla inside the previous whole brain EBRT field and another lesion adjacent to the field in the C2 spinal medulla. Case 2 developed intradural extramedullary metastasis around C6-8 inside the previous EBRT field for the primary lung adenocarcinoma. Case 3 developed multiple spinal intradural extramedullary metastatic deposits after surgical resection and following whole brain EBRT for brain metastasis. We delivered 24 to 36 Gy in 5 to 12 fractions. The treated tumors were stable or decreased in size until the patients' death from the primary cancer (10, 22, and 5 months). Neurological symptoms were stable or improved in all 3 patients. Palliative SRT using Novalis is expected to be safe and effective even if the patient develops spinal intradural metastases within or adjacent to the previous irradiation field.

  13. Salvage Stereotactic Reirradiation With or Without Cetuximab for Locally Recurrent Head-and-Neck Cancer: A Feasibility Study

    SciTech Connect

    Comet, Benedicte; Kramar, Andrew; Faivre-Pierret, Mathieu; Dewas, Sylvain; Coche-Dequeant, Bernard; Degardin, Marian; Lefebvre, Jean-Louis; Lacornerie, Thomas; Lartigau, Eric F.

    2012-09-01

    Purpose: Normal tissues tolerance limits the use of reirradiation for recurrent head-and-neck cancers (HNC). Stereotactic body radiotherapy (SBRT) could offer precise irradiation while sparing healthy tissues. Results of a feasibility study using SBRT with or without cetuximab are reported for reirradiation of recurrent primary HNC. Methods and Materials: Patients with inoperable recurrent, or new primary tumor, in a previously irradiated area were included. Reirradiation dose was 36 Gy in six fractions of 6 Gy to the 85% isodose line covering 95% of the planning target volume. Patients with squamous cell carcinoma received concomitant cetuximab. Results: Between June 2007 and January 2010, 40 patients were prospectively treated for 43 lesions. Median age was 60 and median tumor size was 29 mm. Fifteen patients received concomitant cetuximab and 1 received concomitant cisplatin. Median follow-up was 25.6 months with 34 patients evaluable for tumor response. Median overall survival was 13.6 months and response rate was 79.4% (15 complete and 12 partial responses). Grade 3 toxicity occurred in 4 patients. Conclusion: These results suggest that short SBRT with or without cetuximab is an effective salvage treatment with good response rate in this poor prognosis population with previously irradiated HNC. Treatment is feasible and, with appropriate care to limiting critical structure, acute toxicities are acceptable. A prospective multicenter Phase II trial of SRT and concomitant cetuximab in recurrent HNC squamous cell carcinoma is ongoing.

  14. Survey of Stereotactic Body Radiation Therapy in Japan by the Japan 3-D Conformal External Beam Radiotherapy Group

    SciTech Connect

    Nagata, Yasushi Hiraoka, Masahiro; Mizowaki, Takashi; Narita, Yuichiro; Matsuo, Yukinori; Norihisa, Yoshiki; Onishi, Hiroshi; Shirato, Hiroki

    2009-10-01

    Purpose: To recognize the current status of stereotactic body radiotherapy (SBRT) in Japan, using a nationwide survey conducted by the Japan 3-D Conformal External Beam Radiotherapy Group. Methods and Materials: The questionnaire was sent by mail to 117 institutions. Ninety-four institutions (80%) responded by the end of November 2005. Fifty-three institutions indicated that they have already started SBRT, and 38 institutions had been reimbursed by insurance. Results: A total of 1111 patients with histologically confirmed lung cancer were treated. Among these patients, 637 had T1N0M0 and 272 had T2N0M0 lung cancer. Metastatic lung cancer was found in 702 and histologically unconfirmed lung tumor in 291 patients. Primary liver cancer was found in 207 and metastatic liver cancer in 76 patients. The most frequent schedule used for primary lung cancer was 48Gy in 4 fractions at 22 institutions (52%), followed by 50Gy in 5 fractions at 11 institutions (26%) and 60Gy in 8 fractions at 4 institutions (10%). The tendency was the same for metastatic lung cancer. The average number of personnel involved in SBRT was 1.8 radiation oncologists, including 1.1 certified radiation oncologists, 2.8 technologists, 0.7 nurses, and 0.6 certified quality assurance personnel and 0.3 physicists. The most frequent amount of time for treatment planning was 61-120min, for quality assurance was 50-60min, and for treatment was 30min. There were 14 (0.6% of all cases) reported Grade 5 complications: 11 cases of radiation pneumonitis, 2 cases of hemoptysis, and 1 case of radiation esophagitis. Conclusion: The current status of SBRT in Japan was surveyed.

  15. Integral Whole Brain Dose from Stereotactic Radiosurgery of 47 Metastatic Lesions: A Dosimetric Case Study

    PubMed Central

    Chen, Joseph C; Miller, Michael J; Lodin, Kenneth; Girvigian, Michael R

    2015-01-01

    This report describes the case of a 15-year-old male diagnosed with primary ALK-positive adenocarcinoma of the lung metastatic to the brain. He was treated with surgical resection for a single lesion followed by whole brain radiotherapy and subsequently underwent 10 courses of stereotactic radiosurgery for 47 lesions delivered over a four-year period. Currently, all metastatic lesions in the brain are completely resolved or locally controlled. PMID:26858917

  16. Chest Wall Volume Receiving >30 Gy Predicts Risk of Severe Pain and/or Rib Fracture After Lung Stereotactic Body Radiotherapy

    SciTech Connect

    Dunlap, Neal E.; Cai, Jing; Biedermann, Gregory B.; Yang, Wensha; Benedict, Stanley H.; Sheng Ke; Schefter, Tracey E.; Kavanagh, Brian D.; Larner, James M.

    2010-03-01

    Purpose: To identify the dose-volume parameters that predict the risk of chest wall (CW) pain and/or rib fracture after lung stereotactic body radiotherapy. Methods and Materials: From a combined, larger multi-institution experience, 60 consecutive patients treated with three to five fractions of stereotactic body radiotherapy for primary or metastatic peripheral lung lesions were reviewed. CW pain was assessed using the Common Toxicity Criteria for pain. Peripheral lung lesions were defined as those located within 2.5 cm of the CW. A minimal point dose of 20 Gy to the CW was required. The CW volume receiving >=20, >=30, >=40, >=50, and >=60 Gy was determined and related to the risk of CW toxicity. Results: Of the 60 patients, 17 experienced Grade 3 CW pain and five rib fractures. The median interval to the onset of severe pain and/or fracture was 7.1 months. The risk of CW toxicity was fitted to the median effective concentration dose-response model. The CW volume receiving 30 Gy best predicted the risk of severe CW pain and/or rib fracture (R{sup 2} = 0.9552). A volume threshold of 30 cm{sup 3} was observed before severe pain and/or rib fracture was reported. A 30% risk of developing severe CW toxicity correlated with a CW volume of 35 cm{sup 3} receiving 30 Gy. Conclusion: The development of CW toxicity is clinically relevant, and the CW should be considered an organ at risk in treatment planning. The CW volume receiving 30 Gy in three to five fractions should be limited to <30 cm{sup 3}, if possible, to reduce the risk of toxicity without compromising tumor coverage.

  17. [Stereotactic ablative irradiation for lung cancer].

    PubMed

    Antoni, D; Srour, I; Noël, G; Mornex, F

    2014-01-01

    Stereotactic radiotherapy for lung cancer is a technique that is now well established in the therapeutic arsenal. Protocols are effective, with very high local control rate and an acceptable rate of survival if one takes into account the patient's age and comorbidities. Complications are rare. This review of the literature analyses the whole process of the therapeutic indications and future prospects.

  18. Imaging for Stereotactic Spine Radiotherapy: Clinical Considerations

    SciTech Connect

    Dahele, Max; Zindler, Jaap D.; Sanchez, Esther; Verbakel, Wilko F.; Kuijer, Joost P.A.; Slotman, Ben J.; Senan, Suresh

    2011-10-01

    There is growing interest in the use of stereotactic body radiation therapy (SBRT) for spinal metastases. With the need for accurate target definition and conformal avoidance of critical normal structures, high-quality multimodal imaging has emerged as a key component at each stage of the treatment process. Multidisciplinary collaboration is necessary to optimize imaging protocols and implement imaging advances into routine patient care.

  19. CyberKnife multisession stereotactic radiosurgery and hypofractionated stereotactic radiotherapy for perioptic meningiomas: intermediate-term results and radiobiological considerations.

    PubMed

    Conti, Alfredo; Pontoriero, Antonio; Midili, Federica; Iatì, Giuseppe; Siragusa, Carmelo; Tomasello, Chiara; La Torre, Domenico; Cardali, Salvatore M; Pergolizzi, Stefano; De Renzis, Costantino

    2015-01-01

    Single fraction radiosurgery is conventionally precluded for lesions lying <2-3 mm of the anterior visual pathway because of the radiosensitivity of the optic nerve. We analyzed a series of 64 patients with "perioptic" meningiomas treated by CyberKnife multisession radiosurgery and hypofractionated stereotactic radiotherapy (hSRT). Between July 2007-May 2010, patients were treated using conventional multisession Cyberknife schemes (2-5 fractions) and results were retrospectively analyzed. A radiobiological model was then developed to estimate the best tumor control probability (TCP)/ normal tissue complication probability (NTCP) for these lesions. Resulting dose/fraction schemes were applied to patients treated between May 2010 and July 2014. Data were prospectively collected Twenty-five patients were included in the retrospective part of the study. Median tumor volume was 4.95 cc; median dose was 23.0 Gy and median number of fraction was 5 (range 2-5). No patient had visual deterioration at mean follow-up of 60 ± 12 months. Tumor control was achieved in all cases. Thirty-nine patients were treated according the radiobiology model and results prospectively analyzed. Median tumor volume was 7.5 cc, median dose 25.0 Gy and mean number of fraction 5 (range 3-15). No patient had visual deterioration or tumor progression at mean follow-up of 17 ± 10 months. Conventional multisession CyberKnife treatments (2-5 fractions) provided satisfactory results. Nonetheless, our estimation of TCP suggests the use of higher doses to grant long-term disease control. To achieve higher equivalent doses without significantly increasing the NTCP, we suggest the use of a greater number of fractions, moving to hSRT, in tumors in which the encasement of optic nerves is presumed.

  20. Image-Guided Stereotactic Spine Radiosurgery on a Conventional Linear Accelerator

    SciTech Connect

    Wang Jiazhu Rice, Roger; Mundt, Arno; Sandhu, Ajay; Murphy, Kevin

    2010-04-01

    Stereotactic radiosurgery for spinal metastasis consists of a high radiation dose delivered to the tumor in 1 to 5 fractions. Due to the high radiation dose in a single or fewer treatments, the precision of tumor localization and dose delivery is of great concern. Many groups have published their experiences of spinal radiosurgery with the use of CyberKnife System (Accuray Inc.). In this study, we report in detail our approach to stereotactic spine radiosurgery (SSRS) using a conventional linear accelerator (Varian Trilogy), utilizing the features of kilovolt on-board imaging (kV-OBI) and cone beam computed tomography (CBCT) for image guidance. We present our experience in various aspects of the SSRS procedure, including patient simulation and immobilization, intensity-modulated radiation treatment (IMRT) planning and beam selection, portal dosimetry for patient planning quality assurance (QA), and the use of image guidance in tumor localization prior to and during treatment delivery.

  1. Robotic-arm stereotactic radiosurgery as a definitive treatment for gelastic epilepsy associated with hypothalamic hamartoma

    PubMed Central

    Susheela, Sridhar Papaiah; Revannasiddaiah, Swaroop; Mallarajapatna, Govindarajan J; Basavalingaiah, Ajaikumar

    2013-01-01

    Gelastic seizures, characterised by paroxysms of pathological laughter, are most often associated with an underlying hypothalamic hamartoma. This report describes the definitive treatment using stereotactic-radiosurgery for a teenaged child whose gelastic epilepsy was found refractory to various antiepileptic drugs. Since surgery was not consented to, the child was referred to us for stereotactic radiosurgery (SRS), which was delivered with robotic-arm -SRS to a dose of 30 Gy in five fractions in five consecutive days. A decrease in the frequency of seizures was noticeable as early as within a week, and at 12 months after the procedure, there has been a total cessation of seizures. PMID:24027254

  2. A quality assurance program in stereotactic radiosurgery using the Gamma Knife unit.

    PubMed

    Stuecklschweiger, G F; Feichtinger, K

    1998-10-01

    Because of the large single-fraction dose in stereotactic radiosurgery it is important to guarantee a high geometric and dosimetric accuracy. The paper represent the quality assurance program for the Gamma Knife unit at the University Clinic of Neurosurgery in Graz. The program includes the following procedures: timer control, mechanical radiation isocenter coincidence, trunnion centricity, helmet microswitches test, radiation output and relative helmet factors, dose profile verification, safety interlocks checks and software quality assurance. In summary, the mechanical accuracy and reproducibility of the Gamma Knife unit are < 1 mm. The geometric failure in stereotactic Gamma Knife treatment is limited by the human error in setting the clinical target volume and the spatial accuracy of dose delivery to the patient is limited by the accuracy of modern target localization procedures.

  3. Quality Assurance of Immobilization and Target Localization Systems for Frameless Stereotactic Cranial and Extracranial Hypofractionated Radiotherapy

    SciTech Connect

    Solberg, Timothy D. Medin, Paul M.; Mullins, John; Li Sicong

    2008-05-01

    The success of stereotactic radiosurgery has stimulated significant interest in the application of such an approach for the treatment of extracranial tumors. The potential benefits of reduced healthcare costs and improved patient outcomes that could be realized in a high-precision, hypofractionated treatment paradigm are numerous. Image-guidance technologies are eliminating the historic requirement for rigid head fixation and will also accelerate the clinical implementation of the approach in extracranial sites. An essential prerequisite of 'frameless' stereotactic systems is that they provide localization accuracy consistent with the safe delivery of a therapeutic radiation dose given in one or few fractions. In this report, we reviewed the technologies for frameless localization of cranial and extracranial targets with emphasis on the quality assurance aspects.

  4. Image-guided stereotactic spine radiosurgery on a conventional linear accelerator.

    PubMed

    Wang, Jia-Zhu; Rice, Roger; Mundt, Arno; Sandhu, Ajay; Murphy, Kevin

    2010-01-01

    Stereotactic radiosurgery for spinal metastasis consists of a high radiation dose delivered to the tumor in 1 to 5 fractions. Due to the high radiation dose in a single or fewer treatments, the precision of tumor localization and dose delivery is of great concern. Many groups have published their experiences of spinal radiosurgery with the use of CyberKnife System (Accuray Inc.). In this study, we report in detail our approach to stereotactic spine radiosurgery (SSRS) using a conventional linear accelerator (Varian Trilogy), utilizing the features of kilovolt on-board imaging (kV-OBI) and cone beam computed tomography (CBCT) for image guidance. We present our experience in various aspects of the SSRS procedure, including patient simulation and immobilization, intensity-modulated radiation treatment (IMRT) planning and beam selection, portal dosimetry for patient planning quality assurance (QA), and the use of image guidance in tumor localization prior to and during treatment delivery.

  5. Dose profile measurements during respiratory-gated lung stereotactic radiotherapy: A phantom study

    NASA Astrophysics Data System (ADS)

    Jong, W. L.; Wong, J. H. D.; Ng, K. H.; Ung, N. M.

    2016-03-01

    During stereotactic body radiotherapy, high radiation dose (∼60 Gy) is delivered to the tumour in small fractionation regime. In this study, the dosimetric characteristics were studied using radiochromic film during respiratory-gated and non-gated lung stereotactic body radiotherapy (SBRT). Specifically, the effect of respiratory cycle and amplitude, as well as gating window on the dosimetry were studied. In this study, the dose profiles along the irradiated area were measured. The dose profiles for respiratory-gated radiation delivery with different respiratory or tumour motion amplitudes, gating windows and respiratory time per cycle were in agreement with static radiation delivery. The respiratory gating system was able to deliver the radiation dose accurately (±1.05 mm) in the longitudinal direction. Although the treatment time for respiratory-gated SBRT was prolonged, this approach can potentially reduce the margin for internal tumour volume without compromising the tumour coverage. In addition, the normal tissue sparing effect can be improved.

  6. Patient barriers to implantable cardioverter defibrillator implantation for the primary prevention of sudden cardiac death in patients with heart failure and reduced ejection fraction

    PubMed Central

    Chan, Laura Lihua; Lim, Choon Pin; Aung, Soe Tin; Quetua, Paul; Ho, Kah Leng; Chong, Daniel; Teo, Wee Siong; Sim, David; Ching, Chi Keong

    2016-01-01

    INTRODUCTION Device therapy is efficacious in preventing sudden cardiac death (SCD) in patients with reduced ejection fraction. However, few who need the device eventually opt to undergo implantation and even fewer reconsider their decisions after deliberation. This is due to many factors, including unresolved patient barriers. This study identified the factors that influenced patients’ decision to decline implantable cardioverter defibrillator (ICD) implantation, and those that influenced patients who initially declined an implant to reconsider having one. METHODS A single-centre survey was conducted among 240 patients who had heart failure with reduced ejection fraction and met the ICD implantation criteria, but had declined ICD implantation. RESULTS Participants who refused ICD implantation were mostly male (84%), Chinese (71%), married (72%), currently employed (54%), and had up to primary or secondary education (78%) and monthly income of < SGD 3,000 (51%). Those who were more likely to reconsider their decision were aware that SCD was a consequence of heart failure with reduced ejection fraction, knowledgeable of the preventive role of ICDs, currently employed and aware that their doctor strongly recommended the implant. Based on multivariate analysis, knowledge of the role of ICDs for primary prophylaxis was the most important factor influencing patient decision. CONCLUSION This study identified the demographic and social factors of patients who refused ICD therapy. Knowledge of the role of ICDs in preventing SCD was found to be the strongest marker for reconsidering ICD implantation. Measures to address this information gap may lead to higher rates of ICD implantation. PMID:27075476

  7. Stereotactic body radiotherapy: a critical review for nonradiation oncologists.

    PubMed

    Kirkpatrick, John P; Kelsey, Christopher R; Palta, Manisha; Cabrera, Alvin R; Salama, Joseph K; Patel, Pretesh; Perez, Bradford A; Lee, Jason; Yin, Fang-Fang

    2014-04-01

    Stereotactic body radiotherapy (SBRT) involves the treatment of extracranial primary tumors or metastases with a few, high doses of ionizing radiation. In SBRT, tumor kill is maximized and dose to surrounding tissue is minimized, by precise and accurate delivery of multiple radiation beams to the target. This is particularly challenging, because extracranial lesions often move with respiration and are irregular in shape, requiring careful treatment planning and continual management of this motion and patient position during irradiation. This review presents the rationale, process workflow, and technology for the safe and effective administration of SBRT, as well as the indications, outcome, and limitations for this technique in the treatment of lung cancer, liver cancer, and metastatic disease.

  8. Soot volume fractions and primary particle size estimate by means of the simultaneous two-color-time-resolved and 2D laser-induced incandescence

    NASA Astrophysics Data System (ADS)

    Boiarciuc, A.; Foucher, F.; Mounaïm-Rousselle, C.

    2006-06-01

    An original approach of laser-induced incandescence consisting in the simultaneous recording of the two-color-time-resolved and 2D LII signal is described in this paper. The application of this approach in an atmospheric pressure diffusion flame fueled with isooctane as well as inside the combustion chamber of a diesel engine is presented. Soot volume fraction and primary particle diameters are calculated, and the results are discussed. The mean diameter estimated by fitting the LII modeled curve on the experimental one is compared with the results obtained through soot sampling and microscope analyzing. The influence of the thermal accommodation coefficient and soot refractive index function is also discussed.

  9. Stereotactic Radiotherapy for Intracranial Nonacoustic Schwannomas Including Facial Nerve Schwannoma

    SciTech Connect

    Nishioka, Kentaro; Abo, Daisuke; Aoyama, Hidefumi; Furuta, Yasushi; Onimaru, Rikiya; Onodera, Shunsuke; Sawamura, Yutaka; Ishikawa, Masayori; Fukuda, Satoshi; Shirato, Hiroki

    2009-12-01

    Purpose: Although the effectiveness of stereotactic radiosurgery for nonacoustic schwannomas is currently being assessed, there have been few studies on the efficacy of stereotactic radiotherapy (SRT) for these tumors. We investigated the long-term outcome of SRT for nonacoustic intracranial nerve schwannomas. Methods and Materials: Seventeen patients were treated between July 1994 and December 2006. Of these patients, 7 had schwannomas located in the jugular foramen, 5 in the trigeminal nerve, 4 in the facial nerve, and 1 in the oculomotor nerve. Radiotherapy was used as an initial treatment without surgery in 10 patients (59%) and after initial subtotal resection in the remaining patients. The tumor volume ranged from 0.3 to 31.3 mL (mean, 8.2 mL). The treatment dose was 40 to 54 Gy in 20 to 26 fractions. The median follow-up period was 59.5 months (range, 7.4-122.6 months). Local control was defined as stable or decreased tumor size on follow-up magnetic resonance imaging. Results: Tumor size was decreased in 3 patients, stable in 13, and increased in 1 after SRT. Regarding neurologic symptoms, 8 patients (47%) had improvement and 9 patients were unchanged. One patient had an increase in tumor size and received microsurgical resection at 32 months after irradiation. No patient had worsening of pre-existing neurologic symptoms or development of new cranial nerve deficits at the last follow-up. Conclusions: SRT is an effective alternative to surgical resection for patients with nonacoustic intracranial nerve schwannomas with respect to not only long-term local tumor control but also neuro-functional preservation.

  10. Isolation of Endoplasmic Reticulum, Mitochondria, and Mitochondria-Associated Membrane and Detergent Resistant Membrane Fractions from Transfected Cells and from Human Cytomegalovirus-Infected Primary Fibroblasts.

    PubMed

    Williamson, Chad D; Wong, Daniel S; Bozidis, Petros; Zhang, Aiping; Colberg-Poley, Anamaris M

    2015-09-01

    Increasingly mechanistic virology studies require dependable and sensitive methods for isolating purified organelles containing functional cellular sub-domains. The mitochondrial network is, in part, closely apposed to the endoplasmic reticulum (ER). The mitochondria-associated membrane (MAM) fraction provides direct physical contact between the ER and mitochondria. Characterization of the dual localization and trafficking of human cytomegalovirus (HCMV) UL37 proteins required establishing protocols in which the ER and mitochondria could be reliably separated. Because of its documented role in lipid and ceramide transfer from the ER to mitochondria, a method to purify MAM from infected cells was also developed. Two robust procedures were developed to efficiently isolate mitochondria, ER, and MAM fractions while providing substantial protein yields from HCMV-infected primary fibroblasts and from transfected HeLa cells. Furthermore, this unit includes protocols for isolation of detergent resistant membranes from subcellular fractions as well as techniques that allow visualization of the mitochondrial network disruption that occurs in permissively infected cells by their optimal resolution in Percoll gradients.

  11. Isolation of Endoplasmic Reticulum, Mitochondria, and Mitochondria-Associated Membrane and Detergent Resistant Membrane Fractions from Transfected Cells and from Human Cytomegalovirus-Infected Primary Fibroblasts

    PubMed Central

    Williamson, Chad D.; Wong, Daniel S.; Bozidis, Petros; Zhang, Aiping; Colberg-Poley, Anamaris M.

    2015-01-01

    Increasingly mechanistic virology studies require dependable and sensitive methods for isolating purified organelles containing functional cellular sub-domains. The mitochondrial network is, in part, closely apposed to the endoplasmic reticulum (ER). The mitochondria-associated membrane (MAM) fraction provides direct physical contact between the ER and mitochondria. Characterization of the dual localization and trafficking of human cytomegalovirus (HCMV) UL37 proteins required establishing protocols in which the ER and mitochondria could be reliably separated. Because of its documented role in lipid and ceramide transfer from the ER to mitochondria, a method to purify MAM from infected cells was also developed. Two robust procedures were developed to efficiently isolate mitochondria, ER, and MAM fractions while providing substantial protein yields from HCMV-infected primary fibroblasts and from transfected HeLa cells. Furthermore, this unit includes protocols for isolation of detergent resistant membranes from subcellular fractions as well as techniques that allow visualization of the mitochondria network disruption that occurs in permissively infected cells by their optimal resolution in Percoll gradients. PMID:26331984

  12. Fractionated radiotherapy and radiosurgery of intracranial meningiomas.

    PubMed

    Biau, J; Khalil, T; Verrelle, P; Lemaire, J-J

    2015-06-19

    This review focuses on the role of radiosurgery and fractionated radiotherapy in the management of intracranial meningiomas, which are the most common benign intracranial tumors. Whenever feasible, surgery remains a cornerstone of treatment in effective health care treatment where modern radiotherapy plays an important role. Irradiation can be proposed as first-line treatment, as adjuvant treatment, or as a second-line treatment after recurrence. Stereotactic radiosurgery consists of delivering, a high-dose of radiation with high precision, to the tumor in a single-fraction with a minimal exposure of surrounding healthy tissue. Stereotactic radiosurgery, especially with the gamma knife technique, has reached a high level of success for the treatment of intracranial meningiomas with excellent local control and low morbidity. However, stereotactic radiosurgery is limited by tumor size,<3-4cm, and location, i.e. reasonable distance from the organs at risk. Fractionated radiation therapy is an interesting alternative (5 to 6weeks treatment time) for large inoperable tumors. The results of fractionated radiation therapy seem encouraging as regards both local control and morbidity although long-term prospective studies are still needed.

  13. Neovascular Glaucoma After Stereotactic Radiotherapy for Juxtapapillary Choroidal Melanoma: Histopathologic and Dosimetric Findings

    SciTech Connect

    Fernandes, Bruno F.; Weisbrod, Daniel; Yuecel, Yeni H.; Follwell, Matthew; Krema, Hatem; Heydarian, Mostafa; Xu Wei; Payne, David; McGowan, Hugh; Simpson, Ernest R.; Laperriere, Normand; Sahgal, Arjun

    2011-06-01

    Purpose: Enucleation after stereotactic radiotherapy (SRT) for juxtapapillary choroidal melanoma may be required because of tumor progression (TP) or the development of intractable radiation-induced neovascular glaucoma (NVG). We compare pathologic changes and dosimetric findings in those eyes enucleated secondary to NVG as opposed to TP to better understand potential mechanisms. Methods and Materials: Patients with juxtapapillary choroidal melanoma treated with SRT (70 Gy in 5 fractions, alternate days over a total of 10 days) at the Princess Margaret Hospital, Toronto, Ontario, Canada, who underwent enucleation between 1998 and 2006 were selected. We correlated dosimetric data based on the patient's original SRT treatment plan with histopathologic findings in the retina, optic nerve head, and anterior chamber. A dedicated ocular pathologist reviewed each case in a blinded fashion. Results: Ten eyes in ten patients were enucleated after SRT. Six were enucleated secondary to NVG and four secondary to because of TP. Aggressive tumor features such as invasion of the sclera and epithelioid cell type were observed predominantly in the TP group. Retinal damage was more predominant in the NVG group, as were findings of radiation-related retinal vascular changes of fibrinoid necrosis and hyalinization. No conclusive radiation-related effects were found in the anterior chamber. The maximum point dose and dose to 0.1 cc were lower for the anterior chamber as compared with the dose to the tumor, retina, and optic nerve head. The mean 0.1-cc doses to the retina were 69.4 Gy and 73.5 Gy and to the anterior chamber were 4.9 Gy and 17.3 Gy for the NVG group and tumor progression group, respectively. Conclusions: Our findings suggest that NVG is due to radiation damage to the posterior chamber of the eye rather than primary radiation damage to the anterior segment.

  14. Long-term outcome of stereotactic radiosurgery (Srs) in patients with acoustic neuromas

    SciTech Connect

    Combs, Stephanie E. . E-mail: Stephanie.Combs@med.uni-heidelberg.de; Thilmann, Christoph; Debus, Juergen; Schulz-Ertner, Daniela

    2006-04-01

    Purpose: To evaluate the effectiveness and long-term outcome of stereotactic radiosurgery (SRS) for acoustic neuromas (AN). Patients and Methods: Between 1990 and 2001, we treated 26 patients with 27 AN with SRS. Two patients suffered from neurofibromatosis type 2. Before SRS, a subtotal or total resection had been performed in 3 and in 5 patients, respectively. For SRS, a median single dose of 13 Gy/80% isodose was applied. Results: The overall actuarial 5-year and 10-year tumor control probability in all patients was 91%. Two patients developed tumor progression after SRS at 36 and 48 months. Nineteen patients (73%) were at risk of treatment-related facial nerve toxicity; of these, 1 patient developed a complete facial nerve palsy after SRS (5%). A total of 93% of the lesions treated were at risk of radiation-induced trigeminal neuralgia. Two patients (8%) developed mild dysesthesia of the trigeminal nerve after SRS. The hearing preservation rate in patients with useful hearing before SRS was 55% at 9 years. Conclusion:: Stereotactic radiosurgery results in good local control rates of AN and the risk of cranial nerve toxicities is acceptable. As toxicity is lower with fractionated stereotactic radiotherapy, SRS should be reserved for smaller lesions.

  15. Stereotactic Ablative Radiation Therapy as First Local Therapy for Lung Oligometastases From Colorectal Cancer: A Single-Institution Cohort Study

    SciTech Connect

    Filippi, Andrea Riccardo; Badellino, Serena; Ceccarelli, Manuela; Guarneri, Alessia; Franco, Pierfrancesco; Monagheddu, Chiara; Spadi, Rosella; Ragona, Riccardo; Racca, Patrizia; Ricardi, Umberto

    2015-03-01

    Purpose: To estimate stereotactic ablative radiation therapy (SABR) efficacy and its potential role as an alternative to surgery for the treatment of lung metastases from colorectal cancer. Methods and Materials: Forty consecutive patients who received SABR as first local therapy at the time of lung progression were included, from 2004 to 2014. The primary study endpoint was overall survival. Secondary endpoints were progression-free survival and safety. Results: A single nodule was treated in 26 patients (65%), 2 nodules in 10 patients (25%), 3 in 3 patients (7.5%), and 4 in 1 patient (2.5%), for a total of 59 lesions. The median delivered biological effective dose was 96 Gy, in 1 to 8 daily fractions. Median follow-up time was 20 months (range, 3-72 months). Overall survival rates at 1, 2, and 5 years were, respectively, 84%, 73%, and 39%, with 14 patients (35%) dead. Median overall survival was 46 months. Progression occurred in 25 patients (62.5%), at a median interval of 8 months; failure at SABR site was observed in 3 patients (7.5%). Progression-free survival rates were 49% and 27% at 1 and 2 years, respectively. Discussion: The results of this retrospective exploratory analysis suggest safety and efficacy of SABR in patients affected with colorectal cancer lung oligometastases and urge inclusion of SABR in prospective clinical trials.

  16. [Linear accelerator-based stereotactic radiation treatment of patients with medial middle fossa meningiomas].

    PubMed

    Golanov, A V; Cherekaev, V A; Serova, N K; Pronin, I N; Gorlachev, G E; Kotel'nikova, T M; Podoprigora, A E; Kudriavtseva, P A; Galkin, M V

    2010-01-01

    Medial middle fossa meningiomas are challenging for neurosurgical treatment. Invasion of cranial nerves and vessels leads to high risk of complications after removal of such meningiomas. Currently methods of conformal stereotactic radiation treatment are applied wider and wider for the discussed lesions. During a 3.5-year period 80 patients with medial middle fossa meningiomas were treated in Burdenko Moscow Neurosurgical Institute using linear accelerator "Novalis". In 31 case radiation treatment was preceded by surgical resection. In majority of patients symptoms included cranial nerve dysfunction: oculomotor disturbances in 62.5%, trigeminal impairment--in 37.5%, visual deficit--in 43.8%, facial nerve palsy--in 1.25%. 74 patients underwent radiotherapy with classical fractioning, 2--in hypofractionated mode and 4 received radiosurgery. In cases of classical fractioning mean marginal dose reached 46.3 Gy during 28-33 fractions, in hypofractioning (7 fractions)--31.5 Gy, in radiosurgery--16.25 Gy. Mean follow-up period was 18.4 months (6-42 months). Control of tumor growth was achieved in 97.5% of cases (78 patients): in 42 (52.5%) lesion shrinked, in 36 (45%) stabilization was observed. Clinical examination revealed improvement of visual function in 15 patients (18%) and deterioration in 2 (2.5%). No new neuropathies were found. Stereotactic radiation treatment is the method of choice for medial anterior and middle fossa meningiomas due to effective control of tumor progression and minimal rate of complications.

  17. Stereotactic radiosurgery for multiple brain metastases

    NASA Astrophysics Data System (ADS)

    Lee, Anna; (Josh Yamada, Yoshiya

    2017-01-01

    Whole brain radiation therapy has been the traditional treatment of choice for patients with multiple brain metastases. Although stereotactic radiosurgery is widely accepted for the management to up to 4 brain metastases, its use is still controversial in cases of 5 or more brain metastases. Randomized trials have suggested that stereotactic radiosurgery alone is appropriate in up to 4 metastases without concomitant whole brain radiation. Level 1 evidence also suggests that withholding whole brain radiation may also reduce the impact of radiation on neurocognitive function and also may even offer a survival advantage. A recent analysis of a large multicentre prospective database has suggested that there are no differences in outcomes such as the likelihood of new metastasis or leptomeningeal disease in cases of 2-10 brain metastases, nor in overall survival. Hence in the era of prolonged survival with stage IV cancer, stereotactic radiosurgery is a reasonable alternative to whole brain radiation in order to minimize the impact of treatment upon quality of life without sacrificing overall survival.

  18. Quantitative Proteomic Analysis of Enriched Nuclear Fractions from BK Polyomavirus-infected Primary Renal Proximal Tubule Epithelial Cells

    PubMed Central

    Justice, Joshua L.; Verhalen, Brandy; Kumar, Ranjit; Lefkowitz, Elliot J.; Imperiale, Michael J.; Jiang, Mengxi

    2016-01-01

    Polyomaviruses are a family of small DNA viruses that are associated with a number of severe human diseases, particularly in immunocompromised individuals. The detailed virus-host interactions during lytic polyomavirus infection are not fully understood. Here we report the first nuclear proteomic study with BK polyomavirus (BKPyV) in a primary renal proximal tubule epithelial cell culture system using stable isotope labeling by amino acids in cell culture (SILAC) proteomic profiling coupled with LC-MS/MS. We demonstrated the feasibility of SILAC labeling in these primary cells and subsequently performed reciprocal labeling-infection experiments to identify proteins that are altered by BKPyV infection. Our analyses revealed specific proteins that are significantly up- or down-regulated in the infected nuclear proteome. The genes encoding many of these proteins were not identified in a previous microarray study, suggesting that differential regulation of these proteins may be independent of transcriptional control. Western blotting experiments verified the SILAC proteomic findings. Finally, pathway and network analyses indicated that the host cell DNA damage response signaling and DNA repair pathways are among the cellular processes most affected at the protein level during polyomavirus infection. Our study provides a comprehensive view of the host nuclear proteomic changes during polyomavirus lytic infection and suggests potential novel host factors required for a productive polyomavirus infection. PMID:26354146

  19. In vivo biological effects of stereotactic radiosurgery: A primate model

    SciTech Connect

    Lunsford, L.D.; Altschuler, E.M.; Flickinger, J.C.; Wu, A.; Martinez, A.J. )

    1990-09-01

    Single-fraction, closed skull, small-volume irradiation (radiosurgery) of intact intracranial structures requires accurate knowledge of radiation tolerance. We have developed a baboon model to assess the in vivo destructive radiobiological effects of stereotactic radiosurgery. Three baboons received a single-fraction, 150-Gy lesion of the caudate nucleus, the thalamus, or the pons using the 8-mm diameter collimator of the gamma unit. Serial standard neurodiagnostic tests (neurological examination, computed tomographic scan, magnetic resonance imaging, stable xenon-enhanced computed tomographic scan of cerebral blood flow, somatosensory and brain stem evoked potentials, and myelin basic protein levels of cerebrospinal fluid) were compared with preoperative studies. Magnetic resonance imaging revealed the development of a lesion at the target site between 45 and 60 days after irradiation. Deterioration of the brain stem evoked potentials preceded imaging changes when the lesion encroached on auditory pathways. Myelin basic protein levels increased subsequent to imaging changes. Postmortem neuropathological examination confirmed a well-demarcated radionecrosis of the target volume. The baboon model appears to be an excellent method to study the in vivo biological effects of radiosurgery.

  20. Stereotactic Body Radiation Therapy Boost in Locally Advanced Pancreatic Cancer

    SciTech Connect

    Seo, Young Seok; Kim, Mi-Sook; Yoo, Sung Yul; Cho, Chul Koo; Yang, Kwang Mo; Yoo, Hyung Jun; Choi, Chul Won; Lee, Dong Han; Kim, Jin; Kim, Min Suk; Kang, Hye Jin; Kim, YoungHan

    2009-12-01

    Purpose: To investigate the clinical application of a stereotactic body radiation therapy (SBRT) boost in locally advanced pancreatic cancer patients with a focus on local efficacy and toxicity. Methods and Materials: We retrospectively reviewed 30 patients with locally advanced and nonmetastatic pancreatic cancer who had been treated between 2004 and 2006. Follow-up duration ranged from 4 to 41 months (median, 14.5 months). A total dose of 40 Gy was delivered in 20 fractions using a conventional three-field technique, and then a single fraction of 14, 15, 16, or 17 Gy SBRT was administered as a boost without a break. Twenty-one patients received chemotherapy. Overall and local progression-free survival were calculated and prognostic factors were evaluated. Results: One-year overall survival and local progression-free survival rates were 60.0% and 70.2%, respectively. One patient (3%) developed Grade 4 toxicity. Carbohydrate antigen 19-9 response was found to be an independent prognostic factor for survival. Conclusions: Our findings indicate that a SBRT boost provides a safe means of increasing radiation dose. Based on the results of this study, we recommend that a well controlled Phase II study be conducted on locally advanced pancreatic cancer.

  1. Solubility controlled noble gas fractionation during magmatic degassing: Implications for noble gas compositions of primary melts of OIB and MORB

    NASA Astrophysics Data System (ADS)

    Yamamoto, Junji; Burnard, Pete G.

    2005-02-01

    Noble gas abundances in basaltic glasses from ocean islands (OIBs) are generally lower than those of mid-oceanic ridge basalts (MORBs), contrary to most geodynamic models which usually require that the source of OIBs is less degassed (resulting in higher primordial noble gas abundances) and more trace element enriched (resulting in higher radiogenic noble gas abundances) than the MORB source. Therefore, noble gas abundances in OIBs are often thought to have been reduced by extensive gas loss from the magma before eruption. The extent of magmatic degassing can be tested as it will cause characteristic changes in the composition of the volatiles; notably the 4He/ 40Ar* ratio (where 40Ar* is 40Ar corrected for atmospheric contamination) will increase in residual volatiles due to the higher solubility of He relative to Ar. The degree of He-Ar fractionation for a given fraction of gas loss depends on the ratio of the solubilities, S He/S Ar, which is sensitive to (among other things) the CO 2 and H 2O content of the basalt at the time of degassing. From a global database of OIB and MORB glasses, we show that 4He/ 40Ar* ratios of MORB glasses are broadly consistent with degassing of a magma with an initial 40Ar of ≈1.5 × 10 -5 ccSTP/g, i.e., similar to that of the "popping rock." However, OIB glasses generally have lower 40Ar* concentration for a given 4He/ 40Ar*. While this would appear to require lower 40Ar* abundances in the undegassed OIB magmas, the higher volatile contents of OIBs will reduce S He/S Ar (relative to MORBs) during degassing. By modeling S He/S Ar in OIBs, it is possible to show that extensive degassing of OIBs can occur without dramatically increasing the 4He/ 40Ar* ratio. We show that undegassed 40Ar concentrations of OIB magmas were probably similar to those of MORBs.

  2. Primary mechanism of apoptosis induction in a leukemia cell line by fraction FA-2-b-ss prepared from the mushroom Agaricus blazei Murill.

    PubMed

    Gao, L; Sun, Y; Chen, C; Xi, Y; Wang, J; Wang, Z

    2007-11-01

    Agaricus blazei Murill is a native Brazilian mushroom which functions primarily as an anticancer substance in transplanted mouse tumors. However, the mechanism underlying this function of A. blazei Murill remains obscure. The present study was carried out to investigate the effect of fraction FA-2-b-ss, an RNA-protein complex isolated from A. blazei Murill, on human leukemia HL-60 cells in vitro. Typical apoptotic characteristics were determined by morphological methods using DNA agarose gel electrophoresis and flow cytometry. The growth suppressive effect of fraction FA-2-b-ss on HL-60 cells in vitro occurred in a dose- (5-80 microg/mL) and time-dependent (24-96 h) manner. The proliferation of HL-60 cells (1 x 10(5) cells/mL) treated with 40 microg/mL of fraction FA-2-b-ss for 24-96 h and with 5-80 microg/mL for 96 h resulted in inhibitory rates ranging from 8 to 54.5%, and from 4.9 to 86.3%, respectively. Both telomerase activity determined by TRAP-ELISA and mRNA expression of the caspase-3 gene detected by RT-PCR were increased in HL-60 cells during fraction FA-2-b-ss treatment. The rate of apoptosis correlated negatively with the decrease of telomerase activity (r = 0.926, P < 0.05), but correlated positively with caspase-3 mRNA expression (r = 0.926, P < 0.05). These data show that fraction FA-2-b-ss can induce HL-60 cell apoptosis and that the combined effect of down-regulation of telomerase activity and up-regulation of mRNA expression of the caspase-3 gene could be the primary mechanism of induction of apoptosis. These findings provide strong evidence that fraction FA-2-b-ss could be of interest for the clinical treatment of acute leukemia.

  3. Statistical analysis of target motion in gated lung stereotactic body radiation therapy

    NASA Astrophysics Data System (ADS)

    Zhao, Bo; Yang, Yong; Li, Tianfang; Li, Xiang; Heron, Dwight E.; Saiful Huq, M.

    2011-03-01

    An external surrogate-based respiratory gating technique is a useful method to reduce target margins for the treatment of a moving lung tumor. The success of this technique relies on a good correlation between the motion of the external markers and the internal tumor as well as the repeatability of the respiratory motion. In gated lung stereotactic body radiation therapy (SBRT), the treatment time for each fraction could exceed 30 min due to large fractional dose. Tumor motion may experience pattern changes such as baseline shift during such extended treatment time. The purpose of this study is to analyze tumor motion traces in actual treatment situations and to evaluate the effect of the target baseline shift in gated lung SBRT treatment. Real-time motion data for both the external markers and tumors from 51 lung SBRT treatments with Cyberknife Synchrony technology were analyzed in this study. The treatment time is typically greater than 30 min. The baseline shift was calculated with a rolling average window equivalent to ~20 s and subtracted from that at the beginning. The magnitude of the baseline shift and its relationship with treatment time were investigated. Phase gating simulation was retrospectively performed on 12 carefully selected treatments with respiratory amplitude larger than 5 mm and regular phases. A customized gating window was defined for each individual treatment. It was found that the baseline shifts are specific to each patient and each fraction. Statistical analysis revealed that more than 69% treatments exhibited increased baseline shifts with the lapse of treatment time. The magnitude of the baseline shift could reach 5.3 mm during a 30 min treatment. Gating simulation showed that tumor excursion was caused mainly by the uncertainties in phase gating simulation and baseline shift, the latter being the primary factor. With a 5 mm gating window, 2 out of 12 treatments in the study group showed significant tumor excursion. Baseline shifts

  4. Changes in Follow-up Left Ventricular Ejection Fraction Associated with Outcomes in Primary Prevention ICD and CRT-D Recipients

    PubMed Central

    Zhang, Yiyi; Guallar, Eliseo; Blasco-Colmenares, Elena; Butcher, Barbara; Norgard, Sanaz; Nauffal, Victor; Marine, Joseph E.; Eldadah, Zayd; Dickfeld, Timm; Ellenbogen, Kenneth A.; Tomaselli, Gordon F.; Cheng, Alan

    2015-01-01

    BACKGROUND Heart failure patients with primary prevention implantable cardioverter-defibrillators (ICD) may experience an improvement in left ventricular ejection fraction (LVEF) over time. However, it is unclear how LVEF improvement affects subsequent risk for mortality and sudden cardiac death (SCD). OBJECTIVES We sought to assess changes in LVEF after ICD implantation and the implication of these changes on subsequent mortality and ICD shocks. METHODS We conducted a prospective cohort study of 538 patients with repeated LVEF assessments after ICD implantation for primary prevention of SCD. The primary endpoint was appropriate ICD shock, defined as a shock for ventricular tachyarrhythmias. The secondary endpoint was all-cause mortality. RESULTS Over a mean follow-up of 4.9 years, LVEF decreased in 13.0%, improved in 40.0%, and was unchanged in 47.0% of the patients. In the multivariate Cox models comparing patients with an improved LVEF to those with an unchanged LVEF, the hazard ratios were 0.33 (95% confidence interval [CI]: 0.18 to 0.59) for mortality and 0.29 (95% CI: 0.11 to 0.78) for appropriate shock, respectively. During follow-up, 25% of patients showed an improvement in LVEF to >35% and their risk of appropriate shock decreased but was not eliminated. CONCLUSION Among primary prevention ICD patients, 40.0% had an improved LVEF during follow-up and 25% had LVEF improved to >35%. Changes in LVEF were inversely associated with all-cause mortality and appropriate shock for ventricular tachyarrhythmia. In patients whose follow-up LVEF improved to >35%, the risk of an appropriate shock remained but was markedly decreased. PMID:26227190

  5. Treatment of Five or More Brain Metastases With Stereotactic Radiosurgery

    SciTech Connect

    Hunter, Grant K.; Suh, John H.; Reuther, Alwyn M.; Vogelbaum, Michael A.; Barnett, Gene H.; Angelov, Lilyana; Weil, Robert J.; Neyman, Gennady; Chao, Samuel T.

    2012-08-01

    Purpose: To examine the outcomes of patients with five or more brain metastases treated in a single session with stereotactic radiosurgery (SRS). Methods and Materials: Sixty-four patients with brain metastases treated with SRS to five or more lesions in a single session were reviewed. Primary disease type, number of lesions, Karnofsky performance score (KPS) at SRS, and status of primary and systemic disease at SRS were included. Patients were treated using dosing as defined by Radiation Therapy Oncology Group Protocol 90-05, with adjustments for critical structures. We defined prior whole-brain radiotherapy (WBRT) as WBRT completed >1 month before SRS and concurrent WBRT as WBRT completed within 1 month before or after SRS. Kaplan-Meier estimates and Cox proportional hazard regression were used to determine which patient and treatment factors predicted overall survival (OS). Results: The median OS after SRS was 7.5 months. The median KPS was 80 (range, 60-100). A KPS of {>=}80 significantly influenced OS (median OS, 4.8 months for KPS {<=}70 vs. 8.8 months for KPS {>=}80, p = 0.0097). The number of lesions treated did not significantly influence OS (median OS, 6.6 months for eight or fewer lesions vs. 9.9 months for more than eight, p = nonsignificant). Primary site histology did not significantly influence median OS. On multivariate Cox modeling, KPS and prior WBRT significantly predicted for OS. Whole-brain radiotherapy before SRS compared with concurrent WBRT significantly influenced survival, with a risk ratio of 0.423 (95% confidence interval 0.191-0.936, p = 0.0338). No significant differences were observed when no WBRT was compared with concurrent WBRT or when the no WBRT group was compared with prior WBRT. A KPS of {<=}70 predicted for poorer outcomes, with a risk ratio of 2.164 (95% confidence interval 1.157-4.049, p = 0.0157). Conclusions: Stereotactic radiosurgery to five or more brain lesions is an effective treatment option for patients with

  6. Stereotactic Body Radiation Therapy Can Be Used Safely to Boost Residual Disease in Locally Advanced Non-Small Cell Lung Cancer: A Prospective Study

    SciTech Connect

    Feddock, Jonathan; Arnold, Susanne M.; Shelton, Brent J.; Sinha, Partha; Conrad, Gary; Chen, Li; Rinehart, John; McGarry, Ronald C.

    2013-04-01

    Purpose: To report the results of a prospective, single-institution study evaluating the feasibility of conventional chemoradiation (CRT) followed by stereotactic body radiation therapy (SBRT) as a means of dose escalation for patients with stage II-III non-small cell lung cancer (NSCLC) with residual disease. Methods and Materials: Patients without metastatic disease and with radiologic evidence of limited residual disease (≤5 cm) within the site of the primary tumor and good or complete nodal responses after standard CRT to a target dose of 60 Gy were considered eligible. The SBRT boost was done to achieve a total combined dose biological equivalent dose >100 Gy to the residual primary tumor, consisting of 10 Gy × 2 fractions (20 Gy total) for peripheral tumors, and 6.5 Gy × 3 fractions (19.5 Gy total) for medial tumors using the Radiation Therapy Oncology Group protocol 0813 definitions. The primary endpoint was the development of grade ≥3 radiation pneumonitis (RP). Results: After a median follow-up of 13 months, 4 patients developed acute grade 3 RP, and 1 (2.9%) developed late and persistent grade 3 RP. No patients developed grade 4 or 5 RP. Mean lung dose, V2.5, V5, V10, and V20 values were calculated for the SBRT boost, and none were found to significantly predict for RP. Only advancing age (P=.0147), previous smoking status (P=.0505), and high CRT mean lung dose (P=.0295) were significantly associated with RP development. At the time of analysis, the actuarial local control rate at the primary tumor site was 82.9%, with only 6 patients demonstrating recurrence. Conclusions: Linear accelerator-based SBRT for dose escalation of limited residual NSCLC after definitive CRT was feasible and did not increase the risk for toxicity above that for standard radiation therapy.

  7. Treatment of arteriovenous malformations with stereotactic radiosurgery employing both magnetic resonance angiography and standard angiography as a database

    SciTech Connect

    Petereit, D.; Mehta, M.; Turski, P.; Levin, A.; Strother, C.; Mistretta, C.; Mackie, R.; Gehring, M.; Kubsad, S.; Kinsella, T. )

    1993-01-15

    Twenty-one arteriovenous malformations were prospectively evaluated using magnetic resonance angiography, compare it to stereotactic angiography, employ magnetic resonance angiography in follow-up, and semiquanitfy flow. A correlative evaluation between flow and response to stereotactic radiosurgery was carried out. Phase contrast angiograms were obtained at flow velocities of 400, 200, 100, 60 and 20 cm/sec. The fractionated velocities provided images that selectively demonstrated the arterial and venous components of the arteriovenous malformations. Qualitative assessment of the velocity within the arteriovenous malformations and the presence of fistulae were also determined by multiple velocity images. In addition, 3-dimensional time-of-flight magnetic resonance angiograms were obtained to define the exact size and shape of the nidus. This technique also permitted evaluation of the nidus and feeding arteries for the the presence of low flow aneurysms. Correlation between the two imaging modalities was carried out by subjective and semiquantitative estimation of flow velocity and estimation of nidus size. The following velocity parameters were employed: fast, intermediate, slow, and none. Early analysis suggests that slower flowing arteriovenous malformations may obliterate faster after stereotactic radiosurgery an flow parameters should be employed to predict response. In conclusion, magnetic resonance angiography permits semiquantitative flow velocity assessment and may therefore be superior to stereotactic angiography. An additional advantage of magnetic resonance angiography is the generation of serial transverse images which can replace the conventional CT scan employed for stereotactic radiosurgery treatment planning. A single diagnostic test may therefore be used for diagnosis, radiosurgical treatment planning, follow-up, and treatment selection by identifying patients likely to respond early to radiosurgical management.

  8. The role of stereotactic radiosurgery in the treatment of intramedullary spinal cord neoplasms: a systematic literature review.

    PubMed

    Hernández-Durán, Silvia; Hanft, Simon; Komotar, Ricardo J; Manzano, Glen R

    2016-04-01

    Advances in imaging technology and microsurgical techniques have made microsurgical resection the treatment of choice in cases of symptomatic intramedullary tumors. The use of stereotactic radiosurgery (SRS) for spinal tumors is a recent development, and its application to intramedullary lesions is debated. We conducted a literature search through PubMed's MeSH system, compiling information regarding intramedullary neoplasms treated by SRS. We compiled histology, tumor location and size, treatment modality, radiation dose, fractionation, radiation-induced complications, follow-up, and survival. Ten papers reporting on 52 patients with 70 tumors were identified. Metastatic lesions accounted for 33%, while 67% were primary ones. Tumor location was predominantly cervical (53%), followed by thoracic (33%). Mean volume was 0.55 cm(3) (95% confidence interval (CI), 0.26-0.83). Preferred treatment modality was CyberKnife® (87%), followed by Novalis® (7%) and linear particle accelerator (LINAC) (6%). Mean radiation dose was 22.14 Gy (95% CI, 20.75-23.53), with mean fractionation of 4 (95% CI, 3-5). Three hemangioblastomas showed cyst enlargement. Symptom improvement or stabilization was seen in all but two cases. Radionecrotic spots adjacent to treated areas were seen at autopsy in four lesions, without clinical manifestations. Overall, clinical and radiological outcomes were favorable. Although surgery remains the treatment of choice for symptomatic intramedullary lesions, SRS can be a safe and effective option in selected cases. While this review suggests the overall safety and efficacy of SRS in the management of intramedullary tumors, future studies need randomized, homogeneous patient populations followed over a longer period to provide more robust evidence in its favor.

  9. Poster — Thur Eve — 32: Stereotactic Body Radiation Therapy for Peripheral Lung Lesion: Treatment Planning and Quality Assurance

    SciTech Connect

    Wan, Shuying; Oliver, Michael; Wang, Xiaofang

    2014-08-15

    Stereotactic body radiation therapy (SBRT), due to its high precision for target localizing, has become widely used to treat tumours at various locations, including the lungs. Lung SBRT program was started at our institution a year ago. Eighteen patients with peripheral lesions up to 3 cm diameter have been treated with 48 Gy in 4 fractions. Based on four-dimensional computed tomography (4DCT) simulation, internal target volume (ITV) was delineated to encompass the respiratory motion of the lesion. A margin of 5 mm was then added to create the planning target volume (PTV) for setup uncertainties. There was no expansion from gross tumour volume (GTV) to clinical target volume (CTV). Pinnacle 9.6 was used as the primary treatment planning system. Volumetric modulated arc therapy (VMAT) technique, with one or two coplanar arcs, generally worked well. For quality assurance (QA), each plan was exported to Eclipse 10 and dose calculation was repeated. Dose volume histograms (DVHs) of the targets and organs at risk (OARs) were then compared between the two treatment planning systems. Winston-Lutz tests were carried out as routine machine QA. Patient-specific QA included ArcCheck measurement with an insert, where an ionization chamber was placed at the centre to measure dose at the isocenter. For the first several patients, and subsequently for the plans with extremely strong modulation, Gafchromic film dosimetry was also employed. For each patient, a mock setup was scheduled prior to treatments. Daily pre- and post-CBCT were acquired for setup and assessment of intra-fractional motion, respectively.

  10. Intracranial stereotactic radiosurgery: concepts and techniques.

    PubMed

    De Salles, Antonio A F; Gorgulho, Alessandra A; Pereira, Julio L B; McLaughlin, Nancy

    2013-10-01

    Stereotactic radiosurgery was conceptualized to treat functional diseases of the brain. The need for devices capable of molding the radiation dose to the nuances of intracranial lesions and yet preserve brain function became a challenge. Several devices capable of performing radiosurgery of high quality became commercially available, each with advantages and disadvantages. Speed of radiosurgery delivery for cost effectiveness and comfort for the patient are currently the main developments in the field. Nuances of these devices, procedural steps of radiosurgery, and the team approach of radiosurgery are discussed in this article.

  11. Predictors of Toxicity Associated With Stereotactic Body Radiation Therapy to the Central Hepatobiliary Tract

    SciTech Connect

    Osmundson, Evan C.; Wu, Yufan; Luxton, Gary; Bazan, Jose G.; Koong, Albert C.; Chang, Daniel T.

    2015-04-01

    Purpose: To identify dosimetric predictors of hepatobiliary (HB) toxicity associated with stereotactic body radiation therapy (SBRT) for liver tumors. Methods and Materials: We retrospectively reviewed 96 patients treated with SBRT for primary (53%) or metastatic (47%) liver tumors between March 2006 and November 2013. The central HB tract (cHBT) was defined by a 15-mm expansion of the portal vein from the splenic confluence to the first bifurcation of left and right portal veins. Patients were censored for toxicity upon local progression or additional liver-directed therapy. HB toxicities were graded according to Common Terminology Criteria for Adverse Events version 4.0. To compare different SBRT fractionations, doses were converted to biologically effective doses (BED) by using the standard linear quadratic model α/β = 10 (BED10). Results: Median follow-up was 12.7 months after SBRT. Median BED10 was 85.5 Gy (range: 37.5-151.2). The median number of fractions was 5 (range: 1-5), with 51 patients (53.1%) receiving 5 fractions and 29 patients (30.2%) receiving 3 fractions. In total, there were 23 (24.0%) grade 2+ and 18 (18.8%) grade 3+ HB toxicities. Nondosimetric factors predictive of grade 3+ HB toxicity included cholangiocarcinoma (CCA) histology (P<.0001), primary liver tumor (P=.0087), and biliary stent (P<.0001). Dosimetric parameters most predictive of grade 3+ HB toxicity were volume receiving above BED10 of 72 Gy (V{sub BED10}72) ≥ 21 cm{sup 3} (relative risk [RR]: 11.6, P<.0001), V{sub BED10}66 ≥ 24 cm{sup 3} (RR: 10.5, P<.0001), and mean BED10 (Dmean{sub BED10}) cHBT ≥14 Gy (RR: 9.2, P<.0001), with V{sub BED10}72 and V{sub BED10}66 corresponding to V40 and V37.7 for 5 fractions and V33.8 and V32.0 for 3 fractions, respectively. V{sub BED10}72 ≥ 21 cm{sup 3}, V{sub BED10}66 ≥ 24 cm{sup 3}, and Dmean{sub BED10} cHBT ≥14 Gy were consistently predictive of grade 3+ toxicity on multivariate analysis. Conclusions: V

  12. Cranial Stereotactic Radiosurgery: Current Status of the Initial Paradigm Shifter

    PubMed Central

    Sheehan, Jason P.; Yen, Chun-Po; Lee, Cheng-Chia; Loeffler, Jay S.

    2014-01-01

    The concept of stereotactic radiosurgery (SRS) was first described by Lars Leksell in 1951. It was proposed as a noninvasive alternative to open neurosurgical approaches to manage a variety of conditions. In the following decades, SRS emerged as a unique discipline involving a collegial partnership among neurosurgeons, radiation oncologists, and medical physicists. SRS relies on the precisely guided delivery of high-dose ionizing radiation to an intracranial target. The focused convergence of multiple beams yields a potent therapeutic effect on the target and a steep dose fall-off to surrounding structures, thereby minimizing the risk of collateral damage. SRS is typically administered in a single session but can be given in as many as five sessions or fractions. By providing an ablative effect noninvasively, SRS has altered the treatment paradigms for benign and malignant intracranial tumors, functional disorders, and vascular malformations. Literature on extensive intracranial radiosurgery has unequivocally demonstrated the favorable benefit-to-risk profile that SRS affords for appropriately selected patients. In a departure from conventional radiotherapeutic strategies, radiosurgical principles have recently been extended to extracranial indications such as lung, spine, and liver tumors. The paradigm shift resulting from radiosurgery continues to alter the landscape of related fields. PMID:25113762

  13. Stereotactic ablative radiotherapy for oligometastatic disease in liver.

    PubMed

    Kim, Myungsoo; Son, Seok Hyun; Won, Yong Kyun; Kay, Chul Seung

    2014-01-01

    Liver metastasis in solid tumors, including colorectal cancer, is the most frequent and lethal complication. The development of systemic therapy has led to prolonged survival. However, in selected patients with a finite number of discrete lesions in liver, defined as oligometastatic state, additional local therapies such as surgical resection, radiofrequency ablation, cryotherapy, and radiotherapy can lead to permanent local disease control and improve survival. Among these, an advance in radiation therapy made it possible to deliver high dose radiation to the tumor more accurately, without impairing the liver function. In recent years, the introduction of stereotactic ablative radiotherapy (SABR) has offered even more intensive tumor dose escalation in a few fractions with reduced dose to the adjacent normal liver. Many studies have shown that SABR for oligometastases is effective and safe, with local control rates widely ranging from 50% to 100% at one or two years. And actuarial survival at one and two years has been reported ranging from 72% to 94% and from 30% to 62%, respectively, without severe toxicities. In this paper, we described the definition and technical aspects of SABR, clinical outcomes including efficacy and toxicity, and related parameters after SABR in liver oligometastases from colorectal cancer.

  14. Stereotactic radiotherapy using Novalis for craniopharyngioma adjacent to optic pathways.

    PubMed

    Hashizume, Chisa; Mori, Yoshimasa; Kobayashi, Tatsuya; Shibamoto, Yuta; Nagai, Aiko; Hayashi, Naoki

    2010-06-01

    Craniopharyngioma has benign histological character. However, because of proximity to optic pathways, pituitary gland, and hypothalamus, it may cause severe and permanent damage to such critical structures and can even be life threatening. Total surgical resection is often difficult. This study aims to evaluate treatment results of Novalis stereotactic radiotherapy (SRT) for craniopharyngioma adjacent to optic pathways. Ten patients (six men, four women) with craniopharyngioma and median age of 56.5 years (range 10-74 years) were treated by SRT using Novalis from July 2006 through March 2009. Median volume of tumor was 7.9 ml (range 1.1-21 ml). Three-dimensional noncoplanar five- or seven-beam SRT or coplanar five-beam SRT with intensity modulation was performed. Total dose of 30-39 Gy in 10-15 fractions (median 33 Gy) was delivered to the target. Ten patients were followed up for 9-36 months (median 25.5 months). Response rate was 80% (8/10), and control rate was 100%. Improvement of neurological symptoms was observed in five patients. No serious complications due to SRT were found. SRT for craniopharyngioma may be a safe and effective treatment. Longer follow-up is necessary to determine long-term tumor control or late complications.

  15. Stereotactic Body Radiotherapy Reirradiation for Recurrent Epidural Spinal Metastases

    SciTech Connect

    Mahadevan, Anand; Floyd, Scott; Wong, Eric; Jeyapalan, Suriya; Groff, Michael; Kasper, Ekkehard

    2011-12-01

    Purpose: When patients show progression after conventional fractionated radiation for spine metastasis, further radiation and surgery may not be options. Stereotactic body radiotherapy (SBRT) has been successfully used in treatment of the spine and may be applicable in these cases. We report the use of SBRT for 60 consecutive patients (81 lesions) who had radiological progressive spine metastasis with epidural involvement after previous radiation for spine metastasis. Methods and Materials: SBRT was used with fiducial and vertebral anatomy-based targeting. The radiation dose was prescribed based on the extent of spinal canal involvement; the dose was 8 Gy Multiplication-Sign 3 = 24 Gy when the tumor did not touch the spinal cord and 5 to 6 Gy x 5 = 25 to 30 Gy when the tumor abutted the cord. The cord surface received up to the prescription dose with no hot spots in the cord. Results: The median overall survival was 11 months, and the median progression-free survival was 9 months. Overall, 93% of patients had stable or improved disease while 7% of patients showed disease progression; 65% of patients had pain relief. There was no significant toxicity other than fatigue. Conclusions: SBRT is feasible and appears to be an effective treatment modality for reirradiation after conventional palliative radiation fails for spine metastasis patients.

  16. Clinical accuracy of ExacTrac intracranial frameless stereotactic system

    SciTech Connect

    Ackerly, T.; Lancaster, C. M.; Geso, M.; Roxby, K. J.

    2011-09-15

    Purpose: In this paper, the authors assess the accuracy of the Brainlab ExacTrac system for frameless intracranial stereotactic treatments in clinical practice. Methods: They recorded couch angle and image fusion results (comprising lateral, longitudinal, and vertical shifts, and rotation corrections about these axes) for 109 stereotactic radiosurgery and 166 stereotactic radiotherapy patient treatments. Frameless stereotactic treatments involve iterative 6D image fusion corrections applied until the results conform to customizable pass criteria, theirs being 0.7 mm and 0.5 deg. for each axis. The planning CT slice thickness was 1.25 mm. It has been reported in the literature that the CT slices' thickness impacts the accuracy of localization to bony anatomy. The principle of invariance with respect to patient orientation was used to determine spatial accuracy. Results: The data for radiosurgery comprised 927 image pairs, of which 532 passed (pass ratio of 57.4%). The data for radiotherapy comprised 15983 image pairs, of which 10 050 passed (pass ratio of 62.9%). For stereotactic radiotherapy, the combined uncertainty of ExacTrac calibration, image fusion, and intrafraction motion was (95% confidence interval) 0.290-0.302 and 0.306-0.319 mm in the longitudinal and lateral axes, respectively. The combined uncertainty of image fusion and intrafraction motion in the anterior-posterior coordinates was 0.174-0.182 mm. For stereotactic radiosurgery, the equivalent ranges are 0.323-0.393, 0.337-0.409, and 0.231-0.281 mm. The overall spatial accuracy was 1.24 mm for stereotactic radiotherapy (SRT) and 1.35 mm for stereotactic radiosurgery (SRS). Conclusions: The ExacTrac intracranial frameless stereotactic system spatial accuracy is adequate for clinical practice, and with the same pass criteria, SRT is more accurate than SRS. They now use frameless stereotaxy exclusively at their center.

  17. Dual mode stereotactic localization method and application

    DOEpatents

    Keppel, Cynthia E.; Barbosa, Fernando Jorge; Majewski, Stanislaw

    2002-01-01

    The invention described herein combines the structural digital X-ray image provided by conventional stereotactic core biopsy instruments with the additional functional metabolic gamma imaging obtained with a dedicated compact gamma imaging mini-camera. Before the procedure, the patient is injected with an appropriate radiopharmaceutical. The radiopharmaceutical uptake distribution within the breast under compression in a conventional examination table expressed by the intensity of gamma emissions is obtained for comparison (co-registration) with the digital mammography (X-ray) image. This dual modality mode of operation greatly increases the functionality of existing stereotactic biopsy devices by yielding a much smaller number of false positives than would be produced using X-ray images alone. The ability to obtain both the X-ray mammographic image and the nuclear-based medicine gamma image using a single device is made possible largely through the use of a novel, small and movable gamma imaging camera that permits its incorporation into the same table or system as that currently utilized to obtain X-ray based mammographic images for localization of lesions.

  18. Survival after stereotactic biopsy of malignant gliomas

    SciTech Connect

    Coffey, R.J.; Lunsford, L.D.; Taylor, F.H.

    1988-03-01

    For many patients with malignant gliomas in inaccessible or functionally important locations, stereotactic biopsy followed by radiation therapy (RT) may be a more appropriate initial treatment than craniotomy and tumor resection. We studied the long term survival in 91 consecutive patients with malignant gliomas diagnosed by stereotactic biopsy: 64 had glioblastoma multiforme (GBM) and 27 had anaplastic astrocytoma (AA). Sixty-four per cent of the GBMs and 33% of the AAs involved deep or midline cerebral structures. The treatment prescribed after biopsy, the tumor location, the histological findings, and the patient's age at presentation (for AAs) were statistically important factors determining patient survival. If adequate RT (tumor dose of 5000 to 6000 cGy) was not prescribed, the median survival was less than or equal to 11 weeks regardless of tumor histology or location. The median survival for patients with deep or midline tumors who completed RT was similar in AA (19.4 weeks) and GBM (27 weeks) cases. Histology was an important predictor of survival only for patients with adequately treated lobar tumors. The median survival in lobar GBM patients who completed RT was 46.9 weeks, and that in lobar AA patients who completed RT was 129 weeks. Cytoreductive surgery had no statistically significant effect on survival. Among the clinical factors examined, age of less than 40 years at presentation was associated with prolonged survival only in AA patients. Constellations of clinical features, tumor location, histological diagnosis, and treatment prescribed were related to survival time.

  19. Stereotactic Radiotherapy of Central Nervous System and Head and Neck Lesions, Using a Conformal Intensity-Modulated Radiotherapy System (Peacock™ System)

    PubMed Central

    Ammirati, Mario; Bernardo, Antonio; Ramsinghani, Nilam; Yakoob, Richard; Al-Ghazi, Matthew; Kuo, Jeffrey; Ammirati, Giuseppe

    2001-01-01

    The objective of this article is to evaluate single-fraction or fractionated stereotactic radiotherapy of central nervous system (CNS) and head and neck lesions using intensity-modulated radiotherapy (IMRT) with a commercially available system (Peacock™, Nomos Corporation, Sewickley, PA). This system allows tomotherapeutic delivery of intensity-modulated radiation, that is, the slice-by-slice treatment of the volume of interest with an intensity-modulated beam, making the delivery of highly conformal radiation to the target possible in both single or multiple fractions mode. During an 18-month period, 43 (21 males and 22 females) patients were treated, using a removable cranial screw-fixation device. Ages ranged from 10 to 77 years (mean, 52.2; median, 53.5). Intra- and extra-axial lesions, including head and neck malignancies and spine metastases, were treated. Clinical target volume ranged from 0.77 to 195 cm3 (mean, 47.8; median, 29.90). The dose distribution was normalized to the maximum and was prescribed, in most cases, at the 80% or 90% isodose line (range, 65 to 96%; median, 85%; mean, 83.4%) and ranged from 14 to 80 Gy (mean, 48; median, 50). The number of fractions ranged from 1 to 40 (mean, 23; median, 25). In all but one patient, 90% of the prescription isodose line covered 100% of the clinical target volume. The heterogeneity index (the ratio between the maximum radiation dose and the prescribed dose) ranged between 1.0 and 1.50, whereas the conformity index (the ratio between the volume encompassed by the prescription isodose line and the clinical target volume) ranged between 1.0 and 4.5. There were no complications related to the radiation treatment. With a median follow-up of 6 months, more than 70% of our patients showed decreased lesion size. Stereotactic IMRT of CNS and head and neck lesions can be delivered safely and accurately. The Peacock system delivers stereotactic radiation in single or multiple fractions and has no volume limitations

  20. Innovative Hypofractionated Stereotactic Regimen Achieves Excellent Local Control with No Radiation Necrosis: Promising Results in the Management of Patients with Small Recurrent Inoperable GBM

    PubMed Central

    Pannullo, Susan C.; Minkowitz, Shlomo; Taube, Shoshana; Chang, Jenghwa; Parashar, Bhupesh; Christos, Paul; Wernicke, A.Gabriella

    2016-01-01

    Management of recurrent glioblastoma multiforme (GBM) remains a challenge. Several institutions reported that a single fraction of ≥ 20 Gy for small tumor burden results in excellent local control; however, this is at the expense of a high incidence of radiation necrosis (RN). Therefore, we developed a hypofractionation pattern of 33 Gy/3 fractions, which is a radiobiological equivalent of 20 Gy, with the aim to lower the incidence of RN. We reviewed records of 21 patients with recurrent GBM treated with hypofractionated stereotactic radiation therapy (HFSRT) to their 22 respective lesions. Sixty Gy fractioned external beam radiotherapy was performed as first-line treatment. Median time from primary irradiation to HFSRT was 9.6 months (range: 3.1 – 68.1 months). In HFSRT, a median dose of 33 Gy in 11 Gy fractions was delivered to the 80% isodose line that encompassed the target volume. The median tumor volume was 1.07 cm3 (range: 0.11 – 16.64 cm3). The median follow-up time after HFSRT was 9.3 months (range: 1.7 – 33.6 months). Twenty-one of 23 lesions treated (91.3%) achieved local control while 2/23 (8.7%) progressed. Median time to progression outside of the treated site was 5.2 months (range: 2.2 – 9.6 months). Progression was treated with salvage chemotherapy. Five of 21 patients (23.8%) were alive at the end of this follow-up; two patients remain disease-free. The remaining 16/21 patients (76.2%) died of disease. Treatment was well tolerated by all patients with no acute CTC/RTOG > Grade 2. There was 0% incidence of RN. A prospective trial will be underway to validate these promising results. PMID:27096136

  1. High Statistics Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5-500 GeV with the Alpha Magnetic Spectrometer on the International Space Station

    NASA Astrophysics Data System (ADS)

    Accardo, L.; Aguilar, M.; Aisa, D.; Alvino, A.; Ambrosi, G.; Andeen, K.; Arruda, L.; Attig, N.; Azzarello, P.; Bachlechner, A.; Barao, F.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Battarbee, M.; Battiston, R.; Bazo, J.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Bertucci, B.; Bigongiari, G.; Bindi, V.; Bizzaglia, S.; Bizzarri, M.; Boella, G.; de Boer, W.; Bollweg, K.; Bonnivard, V.; Borgia, B.; Borsini, S.; Boschini, M. J.; Bourquin, M.; Burger, J.; Cadoux, F.; Cai, X. D.; Capell, M.; Caroff, S.; Casaus, J.; Cascioli, V.; Castellini, G.; Cernuda, I.; Cervelli, F.; Chae, M. J.; Chang, Y. H.; Chen, A. I.; Chen, H.; Cheng, G. M.; Chen, H. S.; Cheng, L.; Chikanian, A.; Chou, H. Y.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Consolandi, C.; Contin, A.; Corti, C.; Coste, B.; Cui, Z.; Dai, M.; Delgado, C.; Della Torre, S.; Demirköz, M. B.; Derome, L.; Di Falco, S.; Di Masso, L.; Dimiccoli, F.; Díaz, C.; von Doetinchem, P.; Du, W. J.; Duranti, M.; D'Urso, D.; Eline, A.; Eppling, F. J.; Eronen, T.; Fan, Y. Y.; Farnesini, L.; Feng, J.; Fiandrini, E.; Fiasson, A.; Finch, E.; Fisher, P.; Galaktionov, Y.; Gallucci, G.; García, B.; García-López, R.; Gast, H.; Gebauer, I.; Gervasi, M.; Ghelfi, A.; Gillard, W.; Giovacchini, F.; Goglov, P.; Gong, J.; Goy, C.; Grabski, V.; Grandi, D.; Graziani, M.; Guandalini, C.; Guerri, I.; Guo, K. H.; Habiby, M.; Haino, S.; Han, K. C.; He, Z. H.; Heil, M.; Hoffman, J.; Hsieh, T. H.; Huang, Z. C.; Huh, C.; Incagli, M.; Ionica, M.; Jang, W. Y.; Jinchi, H.; Kanishev, K.; Kim, G. N.; Kim, K. S.; Kirn, Th.; Kossakowski, R.; Kounina, O.; Kounine, A.; Koutsenko, V.; Krafczyk, M. S.; Kunz, S.; La Vacca, G.; Laudi, E.; Laurenti, G.; Lazzizzera, I.; Lebedev, A.; Lee, H. T.; Lee, S. C.; Leluc, C.; Li, H. L.; Li, J. Q.; Li, Q.; Li, Q.; Li, T. X.; Li, W.; Li, Y.; Li, Z. H.; Li, Z. Y.; Lim, S.; Lin, C. H.; Lipari, P.; Lippert, T.; Liu, D.; Liu, H.; Lomtadze, T.; Lu, M. J.; Lu, Y. S.; Luebelsmeyer, K.; Luo, F.; Luo, J. Z.; Lv, S. S.; Majka, R.; Malinin, A.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masi, N.; Maurin, D.; Menchaca-Rocha, A.; Meng, Q.; Mo, D. C.; Morescalchi, L.; Mott, P.; Müller, M.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Nunes, P.; Obermeier, A.; Oliva, A.; Orcinha, M.; Palmonari, F.; Palomares, C.; Paniccia, M.; Papi, A.; Pedreschi, E.; Pensotti, S.; Pereira, R.; Pilo, F.; Piluso, A.; Pizzolotto, C.; Plyaskin, V.; Pohl, M.; Poireau, V.; Postaci, E.; Putze, A.; Quadrani, L.; Qi, X. M.; Rancoita, P. G.; Rapin, D.; Ricol, J. S.; Rodríguez, I.; Rosier-Lees, S.; Rozhkov, A.; Rozza, D.; Sagdeev, R.; Sandweiss, J.; Saouter, P.; Sbarra, C.; Schael, S.; Schmidt, S. M.; Schuckardt, D.; von Dratzig, A. Schulz; Schwering, G.; Scolieri, G.; Seo, E. S.; Shan, B. S.; Shan, Y. H.; Shi, J. Y.; Shi, X. Y.; Shi, Y. M.; Siedenburg, T.; Son, D.; Spada, F.; Spinella, F.; Sun, W.; Sun, W. H.; Tacconi, M.; Tang, C. P.; Tang, X. W.; Tang, Z. C.; Tao, L.; Tescaro, D.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Torsti, J.; Türkoǧlu, C.; Urban, T.; Vagelli, V.; Valente, E.; Vannini, C.; Valtonen, E.; Vaurynovich, S.; Vecchi, M.; Velasco, M.; Vialle, J. P.; Wang, L. Q.; Wang, Q. L.; Wang, R. S.; Wang, X.; Wang, Z. X.; Weng, Z. L.; Whitman, K.; Wienkenhöver, J.; Wu, H.; Xia, X.; Xie, M.; Xie, S.; Xiong, R. Q.; Xin, G. M.; Xu, N. S.; Xu, W.; Yan, Q.; Yang, J.; Yang, M.; Ye, Q. H.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zeissler, S.; Zhang, J. H.; Zhang, M. T.; Zhang, X. B.; Zhang, Z.; Zheng, Z. M.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zimmermann, N.; Zuccon, P.; Zurbach, C.; AMS Collaboration

    2014-09-01

    A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200 GeV the positron fraction no longer exhibits an increase with energy.

  2. High statistics measurement of the positron fraction in primary cosmic rays of 0.5-500 GeV with the alpha magnetic spectrometer on the international space station.

    PubMed

    Accardo, L; Aguilar, M; Aisa, D; Alpat, B; Alvino, A; Ambrosi, G; Andeen, K; Arruda, L; Attig, N; Azzarello, P; Bachlechner, A; Barao, F; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Battarbee, M; Battiston, R; Bazo, J; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Bertucci, B; Bigongiari, G; Bindi, V; Bizzaglia, S; Bizzarri, M; Boella, G; de Boer, W; Bollweg, K; Bonnivard, V; Borgia, B; Borsini, S; Boschini, M J; Bourquin, M; Burger, J; Cadoux, F; Cai, X D; Capell, M; Caroff, S; Carosi, G; Casaus, J; Cascioli, V; Castellini, G; Cernuda, I; Cerreta, D; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, H; Cheng, G M; Chen, H S; Cheng, L; Chikanian, A; Chou, H Y; Choumilov, E; Choutko, V; Chung, C H; Cindolo, F; Clark, C; Clavero, R; Coignet, G; Consolandi, C; Contin, A; Corti, C; Coste, B; Cui, Z; Dai, M; Delgado, C; Della Torre, S; Demirköz, M B; Derome, L; Di Falco, S; Di Masso, L; Dimiccoli, F; Díaz, C; von Doetinchem, P; Du, W J; Duranti, M; D'Urso, D; Eline, A; Eppling, F J; Eronen, T; Fan, Y Y; Farnesini, L; Feng, J; Fiandrini, E; Fiasson, A; Finch, E; Fisher, P; Galaktionov, Y; Gallucci, G; García, B; García-López, R; Gast, H; Gebauer, I; Gervasi, M; Ghelfi, A; Gillard, W; Giovacchini, F; Goglov, P; Gong, J; Goy, C; Grabski, V; Grandi, D; Graziani, M; Guandalini, C; Guerri, I; Guo, K H; Haas, D; Habiby, M; Haino, S; Han, K C; He, Z H; Heil, M; Henning, R; Hoffman, J; Hsieh, T H; Huang, Z C; Huh, C; Incagli, M; Ionica, M; Jang, W Y; Jinchi, H; Kanishev, K; Kim, G N; Kim, K S; Kirn, Th; Kossakowski, R; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M S; Kunz, S; La Vacca, G; Laudi, E; Laurenti, G; Lazzizzera, I; Lebedev, A; Lee, H T; Lee, S C; Leluc, C; Levi, G; Li, H L; Li, J Q; Li, Q; Li, Q; Li, T X; Li, W; Li, Y; Li, Z H; Li, Z Y; Lim, S; Lin, C H; Lipari, P; Lippert, T; Liu, D; Liu, H; Lolli, M; Lomtadze, T; Lu, M J; Lu, Y S; Luebelsmeyer, K; Luo, F; Luo, J Z; Lv, S S; Majka, R; Malinin, A; Mañá, C; Marín, J; Martin, T; Martínez, G; Masi, N; Massera, F; Maurin, D; Menchaca-Rocha, A; Meng, Q; Mo, D C; Monreal, B; Morescalchi, L; Mott, P; Müller, M; Ni, J Q; Nikonov, N; Nozzoli, F; Nunes, P; Obermeier, A; Oliva, A; Orcinha, M; Palmonari, F; Palomares, C; Paniccia, M; Papi, A; Pauluzzi, M; Pedreschi, E; Pensotti, S; Pereira, R; Pilastrini, R; Pilo, F; Piluso, A; Pizzolotto, C; Plyaskin, V; Pohl, M; Poireau, V; Postaci, E; Putze, A; Quadrani, L; Qi, X M; Rancoita, P G; Rapin, D; Ricol, J S; Rodríguez, I; Rosier-Lees, S; Rossi, L; Rozhkov, A; Rozza, D; Rybka, G; Sagdeev, R; Sandweiss, J; Saouter, P; Sbarra, C; Schael, S; Schmidt, S M; Schuckardt, D; Schulz von Dratzig, A; Schwering, G; Scolieri, G; Seo, E S; Shan, B S; Shan, Y H; Shi, J Y; Shi, X Y; Shi, Y M; Siedenburg, T; Son, D; Spada, F; Spinella, F; Sun, W; Sun, W H; Tacconi, M; Tang, C P; Tang, X W; Tang, Z C; Tao, L; Tescaro, D; Ting, Samuel C C; Ting, S M; Tomassetti, N; Torsti, J; Türkoğlu, C; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vaurynovich, S; Vecchi, M; Velasco, M; Vialle, J P; Vitale, V; Volpini, G; Wang, L Q; Wang, Q L; Wang, R S; Wang, X; Wang, Z X; Weng, Z L; Whitman, K; Wienkenhöver, J; Wu, H; Wu, K Y; Xia, X; Xie, M; Xie, S; Xiong, R Q; Xin, G M; Xu, N S; Xu, W; Yan, Q; Yang, J; Yang, M; Ye, Q H; Yi, H; Yu, Y J; Yu, Z Q; Zeissler, S; Zhang, J H; Zhang, M T; Zhang, X B; Zhang, Z; Zheng, Z M; Zhou, F; Zhuang, H L; Zhukov, V; Zichichi, A; Zimmermann, N; Zuccon, P; Zurbach, C

    2014-09-19

    A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200  GeV the positron fraction no longer exhibits an increase with energy.

  3. Stereotactic Ablative Body Radiation Therapy for Octogenarians With Non-Small Cell Lung Cancer

    SciTech Connect

    Takeda, Atsuya; Sanuki, Naoko; Eriguchi, Takahisa; Kaneko, Takeshi; Morita, Satoshi; Handa, Hiroshi; Aoki, Yousuke; Oku, Yohei; Kunieda, Etsuo

    2013-06-01

    Purpose: To retrospectively investigate treatment outcomes of stereotactic ablative body radiation therapy (SABR) for octogenarians with non-small cell lung cancer (NSCLC). Methods and Materials: Between 2005 and 2012, 109 patients aged ≥80 years with T1-2N0M0 NSCLC were treated with SABR: 47 patients had histology-unproven lung cancer; 62 patients had pathologically proven NSCLC. The prescribed doses were either 50 Gy/5 fractions for peripheral tumors or 40 Gy/5 fractions for centrally located tumors. The treatment outcomes, toxicities, and the correlating factors for overall survival (OS) were evaluated. Results: The median follow-up duration after SABR was 24.2 (range, 3.0-64.6) months. Only limited toxicities were observed, except for 1 grade 5 radiation pneumonitis. The 3-year local, regional, and distant metastasis-free survival rates were 82.3%, 90.1%, and 76.8%, respectively. The OS and lung cancer-specific survival rates were 53.7% and 70.8%, respectively. Multivariate analysis revealed that medically inoperable, low body mass index, high T stage, and high C-reactive protein were the predictors for short OS. The OS for the operable octogenarians was significantly better than that for inoperable (P<.01). Conclusions: Stereotactic ablative body radiation therapy for octogenarians was feasible, with excellent OS. Multivariate analysis revealed that operability was one of the predictors for OS. For medically operable octogenarians with early-stage NSCLC, SABR should be prospectively compared with resection.

  4. Patient specific quality control for Stereotactic Ablative Body Radiotherapy (SABR): it takes more than one phantom

    NASA Astrophysics Data System (ADS)

    Kron, T.; Ungureanu, E.; Antony, R.; Hardcastle, N.; Clements, N.; Ukath, J.; Fox, C.; Lonski, P.; Wanigaratne, D.; Haworth, A.

    2017-01-01

    Stereotactic Ablative Body Radiotherapy (SABR) is an extension of the concepts of Stereotactic Radiosurgery from intracranial procedures to extracranial targets. This brings with it new technological challenges for set-up of a SABR program and continuing quality assurance. Compared with intracranial procedures SABR requires consideration of motion and inhomogeneities and has to deal with a much larger variety of targets ranging from lung to liver, kidney and bone. To meet many of the challenges virtually all advances in modern radiotherapy, such as Intensity Modulated and Image Guided Radiation Therapy (IMRT and IGRT) are used. Considering the few fractions and high doses per fraction delivered to complex targets it is not surprising that patient specific quality control is considered essential for safe delivery. Given the variety of targets and clinical scenarios we employ different strategies for different patients to ensure that the most important aspects of the treatment are appropriately tested, be it steep dose gradients, inhomogeneities or the delivery of dose in the presence of motion. The current paper reviews the different approaches and phantoms utilised at Peter MacCallum Cancer Centre for SABR QA.

  5. Stereotactic radiosurgery of prostate cancer - dose distribution for VMAT and CyberKnife techniques

    NASA Astrophysics Data System (ADS)

    Ślosarek, Krzysztof; Osewski, Wojciech; Grządziel, Aleksandra; Stąpór-Fudzińska, Małgorzata; Szlag, Marta

    2016-06-01

    New capabilities of biomedical accelerators allow for very precise depositing of the radiation dose and imaging verification during the therapy. In addition, computer algorithms calculating dose distributions are taking into account the increasing number of physical effects. Therefore, administration of high dose fractionation, which is consistent with radiobiology used in oncology, becomes safer and safer. Stereotactic radiosurgery (SRS), which is very precise irradiation with high dose fractionation is increasingly widespread use in radiotherapy of prostate cancer. For this purpose different biomedical accelerators are used. The aim of this study is to compare dose distributions for two techniques: VMAT and CyberKnife. Statistical analysis was performed for the two groups of patients treated by VMAT technique (25 patients), and CyberKnife technique (15 patients). The analysis shows that the dose distributions are comparable, both in the treated area (prostate) and in the critical organs (rectum, urinary bladder, femoral heads). The results show that stereotactic radiosurgery of prostate cancer can be carried out on CyberKnife accelerator as well as on the classical accelerator with the use of VMAT technique.

  6. Modelling the Gross Primary Productivity of West Africa with the Regional Biomass Model RBM+, using optimized 250 m MODIS FPAR and fractional vegetation cover information

    NASA Astrophysics Data System (ADS)

    Machwitz, Miriam; Gessner, Ursula; Conrad, Christopher; Falk, Ulrike; Richters, Jochen; Dech, Stefan

    2015-12-01

    Global warming associated with climate change is one of the greatest challenges of today's world. Increasing emissions of the greenhouse gas CO2 are considered as a major contributing factor to global warming. One regulating factor of CO2 exchange between atmosphere and land surface is vegetation. Measurements of land cover changes in combination with modelling the Gross Primary Productivity (GPP) can contribute to determine important sources and sinks of CO2. The aim of this study is to accurately model the GPP for a region in West Africa with a spatial resolution of 250 m, and the differentiation of GPP based on woody and herbaceous vegetation. For this purpose, the Regional Biomass Model (RBM) was applied, which is based on a Light Use Efficiency (LUE) approach. The focus was on the spatial enhancement of the RBM from the original 1000-250 m spatial resolution (RBM+). The adaptation to the 250 m scale included the modification of two main input parameters: (1) the fraction of absorbed Photosynthetically Active Radiation (FPAR) based on the 1000 m MODIS MOD15A2 FPAR product which was downscaled to 250 m using MODIS NDVI time series; (2) the fractional cover of woody and herbaceous vegetation, which was improved by using a multi-scale approach. For validation and regional adjustments of GPP and the input parameters, in situ data from a climate station and eddy covariance measurements were integrated. The results of this approach show that the input parameters could be improved significantly: downscaling considerably reduces data gaps of the original FPAR product and the improved dataset differed less than 5.0% from the original data for cloud free regions. The RMSE of the fractional vegetation cover varied between 5.1 and 12.7%. Modelled GPP showed a slight overestimation in comparison to eddy covariance measurements. The in situ data was exceeded by 8.8% for 2005 and by 2.0% for 2006. The model results were converted to NPP and also agreed well with previous NPP

  7. Stereotactic Body Radiation Therapy in Recurrent Hepatocellular Carcinoma

    SciTech Connect

    Huang, Wen-Yen; Jen, Yee-Min; Lee, Meei-Shyuan; Chang, Li-Ping; Chen, Chang-Ming; Ko, Kai-Hsiung; Lin, Kuen-Tze; Lin, Jang-Chun; Chao, Hsing-Lung; Lin, Chun-Shu; Su, Yu-Fu; Fan, Chao-Yueh; Chang, Yao-Wen

    2012-10-01

    Purpose: To examine the safety and efficacy of Cyberknife stereotactic body radiation therapy (SBRT) and its effect on survival in patients of recurrent hepatocellular carcinoma (HCC). Methods and Materials: This was a matched-pair study. From January 2008 to December 2009, 36 patients with 42 lesions of unresectable recurrent HCC were treated with SBRT. The median prescribed dose was 37 Gy (range, 25 to 48 Gy) in 4-5 fractions over 4-5 consecutive working days. Another 138 patients in the historical control group given other or no treatments were selected for matched analyses. Results: The median follow-up time was 14 months for all patients and 20 months for those alive. The 1- and 2-year in-field failure-free rates were 87.6% and 75.1%, respectively. Out-field intrahepatic recurrence was the main cause of failure. The 2-year overall survival (OS) rate was 64.0%, and median time to progression was 8.0 months. In the multivariable analysis of all 174 patients, SBRT (yes vs. no), tumor size ({<=}4 cm vs. >4 cm), recurrent stage (stage IIIB/IV vs. I) and Child-Pugh classification (A vs. B/C) were independent prognostic factors for OS. Matched-pair analysis revealed that patients undergoing SBRT had better OS (2-year OS of 72.6% vs. 42.1%, respectively, p = 0.013). Acute toxicities were mild and tolerable. Conclusion: SBRT is a safe and efficacious modality and appears to be well-tolerated at the dose fractionation we have used, and its use correlates with improved survival in this cohort of patients with recurrent unresectable HCC. Out-field recurrence is the major cause of failure. Further studies of combinations of SBRT and systemic therapies may be reasonable.

  8. First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5-350 GeV

    NASA Astrophysics Data System (ADS)

    Aguilar, M.; Alberti, G.; Alpat, B.; Alvino, A.; Ambrosi, G.; Andeen, K.; Anderhub, H.; Arruda, L.; Azzarello, P.; Bachlechner, A.; Barao, F.; Baret, B.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Basili, A.; Batalha, L.; Bates, J.; Battiston, R.; Bazo, J.; Becker, R.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Berges, P.; Bertucci, B.; Bigongiari, G.; Biland, A.; Bindi, V.; Bizzaglia, S.; Boella, G.; de Boer, W.; Bollweg, K.; Bolmont, J.; Borgia, B.; Borsini, S.; Boschini, M. J.; Boudoul, G.; Bourquin, M.; Brun, P.; Buénerd, M.; Burger, J.; Burger, W.; Cadoux, F.; Cai, X. D.; Capell, M.; Casadei, D.; Casaus, J.; Cascioli, V.; Castellini, G.; Cernuda, I.; Cervelli, F.; Chae, M. J.; Chang, Y. H.; Chen, A. I.; Chen, C. R.; Chen, H.; Cheng, G. M.; Chen, H. S.; Cheng, L.; Chernoplyiokov, N.; Chikanian, A.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Commichau, V.; Consolandi, C.; Contin, A.; Corti, C.; Costado Dios, M. T.; Coste, B.; Crespo, D.; Cui, Z.; Dai, M.; Delgado, C.; Della Torre, S.; Demirkoz, B.; Dennett, P.; Derome, L.; Di Falco, S.; Diao, X. H.; Diago, A.; Djambazov, L.; Díaz, C.; von Doetinchem, P.; Du, W. J.; Dubois, J. M.; Duperay, R.; Duranti, M.; D'Urso, D.; Egorov, A.; Eline, A.; Eppling, F. J.; Eronen, T.; van Es, J.; Esser, H.; Falvard, A.; Fiandrini, E.; Fiasson, A.; Finch, E.; Fisher, P.; Flood, K.; Foglio, R.; Fohey, M.; Fopp, S.; Fouque, N.; Galaktionov, Y.; Gallilee, M.; Gallin-Martel, L.; Gallucci, G.; García, B.; García, J.; García-López, R.; García-Tabares, L.; Gargiulo, C.; Gast, H.; Gebauer, I.; Gentile, S.; Gervasi, M.; Gillard, W.; Giovacchini, F.; Girard, L.; Goglov, P.; Gong, J.; Goy-Henningsen, C.; Grandi, D.; Graziani, M.; Grechko, A.; Gross, A.; Guerri, I.; de la Guía, C.; Guo, K. H.; Habiby, M.; Haino, S.; Hauler, F.; He, Z. H.; Heil, M.; Heilig, J.; Hermel, R.; Hofer, H.; Huang, Z. C.; Hungerford, W.; Incagli, M.; Ionica, M.; Jacholkowska, A.; Jang, W. Y.; Jinchi, H.; Jongmanns, M.; Journet, L.; Jungermann, L.; Karpinski, W.; Kim, G. N.; Kim, K. S.; Kirn, Th.; Kossakowski, R.; Koulemzine, A.; Kounina, O.; Kounine, A.; Koutsenko, V.; Krafczyk, M. S.; Laudi, E.; Laurenti, G.; Lauritzen, C.; Lebedev, A.; Lee, M. W.; Lee, S. C.; Leluc, C.; León Vargas, H.; Lepareur, V.; Li, J. Q.; Li, Q.; Li, T. X.; Li, W.; Li, Z. H.; Lipari, P.; Lin, C. H.; Liu, D.; Liu, H.; Lomtadze, T.; Lu, Y. S.; Lucidi, S.; Lübelsmeyer, K.; Luo, J. Z.; Lustermann, W.; Lv, S.; Madsen, J.; Majka, R.; Malinin, A.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masciocchi, F.; Masi, N.; Maurin, D.; McInturff, A.; McIntyre, P.; Menchaca-Rocha, A.; Meng, Q.; Menichelli, M.; Mereu, I.; Millinger, M.; Mo, D. C.; Molina, M.; Mott, P.; Mujunen, A.; Natale, S.; Nemeth, P.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Nunes, P.; Obermeier, A.; Oh, S.; Oliva, A.; Palmonari, F.; Palomares, C.; Paniccia, M.; Papi, A.; Park, W. H.; Pauluzzi, M.; Pauss, F.; Pauw, A.; Pedreschi, E.; Pensotti, S.; Pereira, R.; Perrin, E.; Pessina, G.; Pierschel, G.; Pilo, F.; Piluso, A.; Pizzolotto, C.; Plyaskin, V.; Pochon, J.; Pohl, M.; Poireau, V.; Porter, S.; Pouxe, J.; Putze, A.; Quadrani, L.; Qi, X. N.; Rancoita, P. G.; Rapin, D.; Ren, Z. L.; Ricol, J. S.; Riihonen, E.; Rodríguez, I.; Roeser, U.; Rosier-Lees, S.; Rossi, L.; Rozhkov, A.; Rozza, D.; Sabellek, A.; Sagdeev, R.; Sandweiss, J.; Santos, B.; Saouter, P.; Sarchioni, M.; Schael, S.; Schinzel, D.; Schmanau, M.; Schwering, G.; Schulz von Dratzig, A.; Scolieri, G.; Seo, E. S.; Shan, B. S.; Shi, J. Y.; Shi, Y. M.; Siedenburg, T.; Siedling, R.; Son, D.; Spada, F.; Spinella, F.; Steuer, M.; Stiff, K.; Sun, W.; Sun, W. H.; Sun, X. H.; Tacconi, M.; Tang, C. P.; Tang, X. W.; Tang, Z. C.; Tao, L.; Tassan-Viol, J.; Ting, Samuel C. C.; Ting, S. M.; Titus, C.; Tomassetti, N.; Toral, F.; Torsti, J.; Tsai, J. R.; Tutt, J. C.; Ulbricht, J.; Urban, T.; Vagelli, V.; Valente, E.; Vannini, C.; Valtonen, E.; Vargas Trevino, M.; Vaurynovich, S.; Vecchi, M.; Vergain, M.; Verlaat, B.; Vescovi, C.; Vialle, J. P.; Viertel, G.; Volpini, G.; Wang, D.; Wang, N. H.; Wang, Q. L.; Wang, R. S.; Wang, X.; Wang, Z. X.; Wallraff, W.; Weng, Z. L.; Willenbrock, M.; Wlochal, M.; Wu, H.; Wu, K. Y.; Wu, Z. S.; Xiao, W. J.; Xie, S.; Xiong, R. Q.; Xin, G. M.; Xu, N. S.; Xu, W.; Yan, Q.; Yang, J.; Yang, M.; Ye, Q. H.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zeissler, S.; Zhang, J. G.; Zhang, Z.; Zhang, M. M.; Zheng, Z. M.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zuccon, P.; Zurbach, C.

    2013-04-01

    A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8×106 positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ˜250GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

  9. Stereotactic Radiosurgery for Acoustic Neuromas: What Happens Long Term?

    SciTech Connect

    Roos, Daniel E.; Potter, Andrew E.; Brophy, Brian P.

    2012-03-15

    Purpose: To determine the clinical outcomes for acoustic neuroma treated with low-dose linear accelerator stereotactic radiosurgery (SRS) >10 years earlier at the Royal Adelaide Hospital using data collected prospectively at a dedicated SRS clinic. Methods and Materials: Between November 1993 and December 2000, 51 patients underwent SRS for acoustic neuroma. For the 44 patients with primary SRS for sporadic (unilateral) lesions, the median age was 63 years, the median of the maximal tumor diameter was 21 mm (range, 11-34), and the marginal dose was 14 Gy for the first 4 patients and 12 Gy for the other 40. Results: The crude tumor control rate was 97.7% (1 patient required salvage surgery for progression at 9.75 years). Only 8 (29%) of 28 patients ultimately retained useful hearing (interaural pure tone average {<=}50 dB). Also, although the Kaplan-Meier estimated rate of hearing preservation at 5 years was 57% (95% confidence interval, 38-74%), this decreased to 24% (95% confidence interval, 11-44%) at 10 years. New or worsened V and VII cranial neuropathy occurred in 11% and 2% of patients, respectively; all cases were transient. No case of radiation oncogenesis developed. Conclusions: The long-term follow-up data of low-dose (12-14 Gy) linear accelerator SRS for acoustic neuroma have confirmed excellent tumor control and acceptable cranial neuropathy rates but a continual decrease in hearing preservation out to {>=}10 years.

  10. Manganese accumulation in membrane fractions of primary astrocytes is associated with decreased γ-aminobutyric acid (GABA) uptake, and is exacerbated by oleic acid and palmitate.

    PubMed

    Fordahl, Steve C; Erikson, Keith M

    2014-05-01

    Manganese (Mn) exposure interferes with GABA uptake; however, the effects of Mn on GABA transport proteins (GATs) have not been identified. We sought to characterize how Mn impairs GAT function in primary rat astrocytes. Astrocytes exposed to Mn (500 μM) had significantly reduced (3)H-GABA uptake despite no change in membrane or cytosolic GAT3 protein levels. Co-treatment with 100 μM oleic or palmitic acids (both known to be elevated in Mn neurotoxicity), exacerbated the Mn-induced decline in (3)H-GABA uptake. Mn accumulation in the membrane fraction of astrocytes was enhanced with fatty acid administration, and was negatively correlated with (3)H-GABA uptake. Furthermore, control cells exposed to Mn only during the experimental uptake had significantly reduced (3)H-GABA uptake, and the addition of GABA (50 μM) blunted cytosolic Mn accumulation. These data indicate that reduced GAT function in astrocytes is influenced by Mn and fatty acids accumulating at or interacting with the plasma membrane.

  11. Stereotactic Body Radiation Therapy for Pancreatic Cancer.

    PubMed

    Goodman, Karyn A

    2016-01-01

    The role of radiation therapy in the management of pancreatic cancer represents an area of some controversy. However, local disease progression remains a significant cause of morbidity and even mortality for patients with this disease. Stereotactic body radiotherapy (SBRT) is an emerging treatment option for pancreatic cancer, primarily for locally advanced (unresectable) disease as it can provide a therapeutic benefit with significant advantages for patients' quality of life over standard conventional chemoradiation. There may also be a role for SBRT as neoadjuvant therapy for patients with borderline resectable disease to allow conversion to resectability. The objective of this review is to present the data supporting SBRT in pancreatic cancer as well as the potential limitations and caveats of current studies.

  12. Integration of Functional MRI and White Matter Tractography in Stereotactic Radiosurgery Clinical Practice

    SciTech Connect

    Pantelis, Evaggelos; Papadakis, Nikolaos; Verigos, Kosmas; Stathochristopoulou, Irene; Antypas, Christos; Lekas, Leonidas; Tzouras, Argyrios; Georgiou, Evangelos; Salvaras, Nikolaos

    2010-09-01

    Purpose: To study the efficacy of the integration of functional magnetic resonance imaging (fMRI) and diffusion tensor imaging tractography data into stereotactic radiosurgery clinical practice. Methods and Materials: fMRI and tractography data sets were acquired and fused with corresponding anatomical MR and computed tomography images of patients with arteriovenous malformation (AVM), astrocytoma, brain metastasis, or hemangioma and referred for stereotactic radiosurgery. The acquired data sets were imported into a CyberKnife stereotactic radiosurgery system and used to delineate the target, organs at risk, and nearby functional structures and fiber tracts. Treatment plans with and without the incorporation of the functional structures and the fiber tracts into the optimization process were developed and compared. Results: The nearby functional structures and fiber tracts could receive doses of >50% of the maximum dose if they were excluded from the planning process. In the AVM case, the doses received by the Broadmann-17 structure and the optic tract were reduced to 700 cGy from 1,400 cGy and to 1,200 cGy from 2,000 cGy, respectively, upon inclusion into the optimization process. In the metastasis case, the motor cortex received 850 cGy instead of 1,400 cGy; and in the hemangioma case, the pyramidal tracts received 780 cGy instead of 990 cGy. In the astrocytoma case, the dose to the motor cortex bordering the lesion was reduced to 1,900 cGy from 2,100 cGy, and therefore, the biologically equivalent dose in three fractions was delivered instead. Conclusions: Functional structures and fiber tracts could receive high doses if they were not considered during treatment planning. With the aid of fMRI and tractography images, they can be delineated and spared.

  13. Intensity-modulated stereotactic radiotherapy (IMSRT) for skull-base meningiomas

    SciTech Connect

    Yenice, Kamil M. . E-mail: kyenice@radonc.uchicago.edu; Narayana, Ashwatha; Chang, Jenghwa; Gutin, Philip H.; Amols, Howard I.

    2006-11-15

    Purpose: To investigate the potential benefits of a micromultileaf collimator ({mu}MLC) -based intensity-modulated stereotactic radiotherapy (IMSRT) in skull-base meningiomas. Methods and Materials: Seven patients with inoperable or recurrent small-volume (1.7-15.5 cc) skull-base meningiomas were treated with IMSRT to 54 Gy in 30 fractions using a {mu}MLC in the dynamic mode. IMSRT plan quality was evaluated in comparison with the conformal stereotactic radiotherapy technique, using the same beam arrangement and static delivery with the {mu}MLC. Plans were compared using multiple dose distributions and dose-volume histograms for the planning target volume and organs at risk. The conformity and uniformity metrics, as well as normal-tissue complication probabilities, were calculated for the two techniques. Follow-up with MRI and clinical examination was performed at regular intervals. Results: With a mean follow-up of 17 months, local control has been achieved in all cases, and no treatment-related toxicities have been noted. For cavernous sinus tumors overlapping with optic apparatus, IMSRT has improved the dose uniformity within the target on average by 8%, which resulted in a reduction of the estimated chiasm normal-tissue complication probability by up to 65%. Conclusions: Intensity-modulated stereotactic radiotherapy can be safely delivered to improve the dose distributions in select skull-base meningiomas with an appreciable concomitant dose reduction to involved critical structures. Longer follow-up with a larger patient group is necessary to demonstrate sustained tumor control and low morbidity with IMSRT for small inoperable, recurrent, or subtotally resected meningiomas.

  14. Robotic Stereotactic Radioablation Concomitant With Neo-Adjuvant Chemotherapy for Breast Tumors

    SciTech Connect

    Bondiau, Pierre-Yves; Bahadoran, Phillipe; Lallement, Michel; Birtwisle-Peyrottes, Isabelle; Chapellier, Claire; Chamorey, Emmanuel; Courdi, Adel; Quielle-Roussel, Catherine; Thariat, Juliette; Ferrero, Jean-Marc

    2009-11-15

    Purpose: Robotic stereotactic radioablation (RSR) allows stereotactic irradiation of thoracic tumors; however, it has never been used for breast tumors and may have a real potential. We conducted a Phase I study, including neoadjuvant chemotherapy (NACT), a two-level dose-escalation study (6.5 Gy x 3 fractions and 7.5 Gy x 3 fractions) using RSR and breast-conserving surgery followed by conventional radiotherapy. Materials and Methods: To define toxicity, we performed a dermatologic exam (DE) including clinical examination by two independent observers and technical examination by colorimetry, dermoscopy, and skin ultrasound. DE was performed before NACT (DE0), at 36 days (DE1), at 56 days (DE2), after the NACT treatment onset, and before surgery (DE3). Surgery was performed 4-8 weeks after the last chemotherapy session. A pathologic examination was also performed. Results: There were two clinical complete responses and four clinical partial responses at D56 and D85. Maximum tolerable dose was not reached. All patients tolerated RSR with no fatigue; 2 patients presented with mild pain after the third fraction of the treatment. There was no significant toxicity measured with ultrasound and dermoscopy tests. Postoperative irradiation (50 Gy) has been delivered without toxicity. Conclusion: The study showed the feasibility of irradiation with RSR combined with chemotherapy and surgery for breast tumors. There was no skin toxicity at a dose of 19.5 Gy or 22.5 Gy delivered in three fractions combined with chemotherapy. Lack of toxicity suggested that the dose could be increased further. Pathologic response was acceptable.

  15. [Stereotactic radiotherapy and radiosurgery in treatment of patients with intracranial schwannomas].

    PubMed

    Zolotova, S V; Golanov, A V; Kotel'nikova, T M; Soboleva, O I; Gorlachev, G E; Fil'chenkova, N A; Nikonova, N G; Kapitanov, D N; Makhmudov, U B; Shimanskiĭ, V N; Arutiunov, N V; Pronin, I N

    2010-01-01

    Aim of this study is to assess the role of stereotactic radiosurgery (SRS) and radiotherapy (SRT) in management of cranial nerves schwannomas by analysis of tumor control, clinical response and variables affecting treatment outcomes. Between April 2005 and January 2009 patients with schwannomas of VIII (63), V (14) and caudal nerves (2) were treated in Burdenko Moscow Neurosurgical Institute using linear accelerator. Mean age was 49 years (13-82). In 42 cases radiation treatment was preceded by surgical resection. 13 patients had type I or II neurofibromatosis. Mean volume of the tumor was 3.9 cm3 (0.5-14.4 cm3) and 13.4 cm3 (2.8-41.3 cm3) for SRS and SRT, respectively. Mean SRS dose was 12 Gy (10.8-14.4 Gy) for vestibular schwannomas and 15 Gy (13.2-18 Gy) for schwannomas of other nerves. In hypofractionated SRT the dose of 35 Gy was delivered in 7 fractions or 30 Gy in 6 fractions. In cases of classical fractioning total dose of 50-60 Gy was divided into daily fractions of 1.8-2.0 Gy. Radiographic tumor control rate reached 97.5% at the last follow-up. 5 patients experienced trigeminal dysfunction, it was transient in 3 cases and persistent in 2. Permanent decline in House-Brackmann facial nerve scale developed in 2 of 79 patients. After treatment effective hearing (class I-II) was preserved in 7 of 9 patients (67%) who had same level of hearing before SRS. Linear accelerator-based stereotactic radiation treatment provides long-term tumor control associated with high rates of preservation of neurological functions. No further tumor surgery was necessary in 100% of cases with solitary tumors with a minimal follow-up of 5 years.

  16. TU-G-BRA-01: Assessing Radiation-Induced Reductions in Regional Lung Perfusion Following Stereotactic Radiotherapy for Lung Cancer

    SciTech Connect

    McGurk, R; Green, R; Lawrence, M; Schreiber, E; Das, S; Zagar, T; Marks, L; Sheikh, A; McCartney, W; Rivera, P

    2015-06-15

    Purpose: The dose-dependent nature of radiation therapy (RT)-induced lung injury following hypo-fractionated stereotactic RT is unclear. We herein report preliminary results of a prospective study assessing the magnitude of RT-induced reductions in regional lung perfusion following hypo-fractionated stereotactic RT. Methods: Four patients undergoing hypo-fractionated stereotactic lung RT (SBRT: 12 Gy x 4 fractions or 10 Gy x 5 fractions) had a pre-treatment SPECT (single-photon emission computed tomography) perfusion scan providing a 3D map of regional lung perfusion. Scans were repeated 3–6 months post-treatment. Pre- and post SPECT scans were registered to the planning CT scan (and hence the 3D dose data). Changes in regional perfusion (counts per cc on the pre-post scans) were computed in regions of the lung exposed to different doses of radiation (in 5 Gy intervals), thus defining a dose-response function. SPECT scans were internally normalized to the regions receiving <5 Gy. Results: At 3 months post-RT, the changes in perfusion are highly variable. At 6 months, there is a consistent dose-dependent reduction in regional perfusion. The average percent decline in regional perfusion was 10% at 15–20 Gy, 20% at 20–25 Gy, and 30% at 25–30 Gy representing a relatively linear dose response with an approximate 2% reduction per Gray for doses in excess of 10 Gy. There was a subtle increase in perfusion in the lung receiving <10 Gy. Conclusion: Hypo-fractionated stereotactic RT appears to cause a dose-dependent reduction in regional lung perfusion. There appears to be a threshold effect with no apparent perfusion loss at doses <10 Gy, though this might be in part due to the normalization technique used. Additional data is needed from a larger number of patients to better assess this issue. This sort of data can be used to assist optimizing RT treatment plans that minimize the risk of lung injury. Partly supported by the NIH (CA69579) and the Lance Armstrong

  17. High-dose MVCT image guidance for stereotactic body radiation therapy

    SciTech Connect

    Westerly, David C.; Schefter, Tracey E.; Kavanagh, Brian D.; Chao, Edward; Lucas, Dan; Flynn, Ryan T.; Miften, Moyed

    2012-08-15

    Purpose: Stereotactic body radiation therapy (SBRT) is a potent treatment for early stage primary and limited metastatic disease. Accurate tumor localization is essential to administer SBRT safely and effectively. Tomotherapy combines helical IMRT with onboard megavoltage CT (MVCT) imaging and is well suited for SBRT; however, MVCT results in reduced soft tissue contrast and increased image noise compared with kilovoltage CT. The goal of this work was to investigate the use of increased imaging doses on a clinical tomotherapy machine to improve image quality for SBRT image guidance. Methods: Two nonstandard, high-dose imaging modes were created on a tomotherapy machine by increasing the linear accelerator (LINAC) pulse rate from the nominal setting of 80 Hz, to 160 Hz and 300 Hz, respectively. Weighted CT dose indexes (wCTDIs) were measured for the standard, medium, and high-dose modes in a 30 cm solid water phantom using a calibrated A1SL ion chamber. Image quality was assessed from scans of a customized image quality phantom. Metrics evaluated include: contrast-to-noise ratios (CNRs), high-contrast spatial resolution, image uniformity, and percent image noise. In addition, two patients receiving SBRT were localized using high-dose MVCT scans. Raw detector data collected after each scan were used to reconstruct standard-dose images for comparison. Results: MVCT scans acquired using a pitch of 1.0 resulted in wCTDI values of 2.2, 4.7, and 8.5 cGy for the standard, medium, and high-dose modes respectively. CNR values for both low and high-contrast materials were found to increase with the square root of dose. Axial high-contrast spatial resolution was comparable for all imaging modes at 0.5 lp/mm. Image uniformity was improved and percent noise decreased as the imaging dose increased. Similar improvements in image quality were observed in patient images, with decreases in image noise being the most notable. Conclusions: High-dose imaging modes are made possible on a

  18. Stereotactic body radiation therapy for prostate cancer: is the technology ready to be the standard of care?

    PubMed

    Zaorsky, Nicholas G; Studenski, Matthew T; Dicker, Adam P; Gomella, Leonard; Den, Robert B

    2013-05-01

    Prostate cancer is the second most prevalent solid tumor diagnosed in men in the United States and Western Europe. Stereotactic body radiation therapy (SBRT) is touted as a superior type of external beam radiation therapy (EBRT) for the treatment of various tumors. SBRT developed from the theory that high doses of radiation from brachytherapy implant seeds could be recapitulated from advanced technology of radiation treatment planning and delivery. Moreover, SBRT has been theorized to be advantageous compared to other RT techniques because it has a treatment course shorter than that of conventionally fractionated EBRT (a single session, five days per week, for about two weeks vs. eight weeks), is non-invasive, is more effective at killing tumor cells, and is less likely to cause damage to normal tissue. In areas of the US and Europe where there is limited access to RT centers, SBRT is frequently being used to treat prostate cancer, even though long-term data about its efficacy and safety are not well established. We review the impetus behind SBRT and the current clinical evidence supporting its use for prostate cancer, thus providing oncologists and primary care physicians with an understanding of the continually evolving field of prostate radiation therapy. Studies of SBRT provide encouraging results of biochemical control and late toxicity. However, they are limited by a number of factors, including short follow-up, exclusion of intermediate- and high-risk patients, and relatively small number of patients treated. Currently, SBRT regimens should only be used in the context of clinical trials.

  19. Stereotactic Interstitial Radiosurgery With the Photon Radiosurgery System (PRS) for Metastatic Brain Tumors: A Prospective Single-Center Clinical Trial

    SciTech Connect

    Pantazis, Georgios; Trippel, Michael; Birg, Walter; Ostertag, Christoph B.; Nikkhah, Guido

    2009-12-01

    Purpose: To evaluate the efficacy and the treatment outcome of tumor patients being treated stereotactically with a miniature X-ray generator (Photon Radiosurgery System, PRS). Methods and Materials: Thirty-five patients with histologically diagnosed cerebral metastases were treated with a single fraction of stereotactic interstitial irradiation (median, 18 Gy). Clinical and neuroimaging evaluation were assessed at 2-, 6-, and 12-week intervals postoperatively and every 3 months thereafter. Survival, local control, and distant and overall brain freedom from progression were obtained using the Kaplan-Meier method. Results: Median survival was 7.37 months and the actuarial survival rates at 6 and 12 months were 60.0% and 34.3%, respectively. Acute complications on six patients were associated with shorter survival. Local tumor control at the initial stage and at the last follow-up were 82% and 50%. Eighteen patients (53%) developed distant brain metastases after treatment. At 1 year, the local control rate and distant and overall brain freedom from progression were 33.0%, 43.3%, and 14.7%, respectively. A shorter local tumor control was observed by PRS treatment of a recurrent tumor and by irregular tumor configuration. Conclusions: Interstitial radiosurgery with the PRS requires continued investigation. It allows for an immediate and potentially cost-efficient treatment for patients with singular, small (<= 6.36 cm{sup 3}; or <= 2.3 cm) spherical brain metastasis subsequent to a stereotactic biopsy.

  20. Possible Misinterpretation of Demarcated Solid Patterns of Radiation Fibrosis on CT Scans as Tumor Recurrence in Patients Receiving Hypofractionated Stereotactic Radiotherapy for Lung Cancer

    SciTech Connect

    Takeda, Atsuya; Kunieda, Etsuo Takeda, Toshiaki; Tanaka, Michio; Sanuki, Naoko; Fujii, Hirofumi; Shigematsu, Naoyuki; Kubo, Atsushi M.D.

    2008-03-15

    Purpose: To retrospectively analyze opacity changes near primary lung cancer tumors irradiated by using hypofractionated stereotactic radiotherapy (HSRT) to determine the presence or absence of tumor recurrence. Methods and Materials: After review-board approval for a retrospective study, we examined data from 50 patients treated with curative intent for proven or highly suspected localized peripheral-lung cancer and followed up for at least 12 months. All patients had received 50 Gy in five fractions (80% isodose) and were followed up monthly with chest X-ray until clinical and X-ray findings stabilized. Follow-up computed tomography scans were performed 1 and 3 months after HSRT and thereafter at 3-month intervals during the first 2 years. Results: Median follow-up was 30.4 months (range, 12.0-73.8 months). Abnormal opacities that were suspicious for recurrent tumor appeared in 20 patients at a median of 20.7 months (range, 5.9-61.4 months). Only 3 patients were finally found to have recurrence; 14 were recurrence free but were suspected to have fibrosis, and findings for the other 3 patients were considered equivocal because of a short follow-up period ({<=}6 months). Conclusion: Radiation fibrosis, which may occur 1 year or longer after completion of HSRT, is difficult to distinguish from tumor recurrence. Even when opacities increase on follow-up radiologic scans, recurrence cannot be diagnosed conclusively based on image findings; biopsy occasionally is warranted.

  1. Hypofractionated stereotactic radiotherapy combined with topotecan in recurrent malignant glioma

    SciTech Connect

    Wurm, Reinhard E. . E-mail: Reinhard.Wurm@charite.de; Kuczer, David A.; Schlenger, Lorenz; Matnjani, Gesa; Scheffler, Dirk; Cosgrove, Vivian P.; Ahlswede, Julia; Woiciechowsky, Christian; Budach, Volker

    2006-11-15

    Purpose: To assess hypofractionated stereotactic radiotherapy (H-SRT) with concurrent topotecan in patients with recurrent malignant glioma. Methods and Materials: Between February 1998 and December 2001, 25 patients with recurrent malignant glioma were treated in a phase I-II study (8 females and 17 males; median age, 45 years; range, 11-66 years; median Karnofsky performance status, 80%, range, 50-100%; median Mini Mental Standard Examination score, 25 points; range, 10-30 points). Of the 25 patients, 20% had World Health Organization Grade III and 80% World Health Organization Grade IV glioma. All patients had been treated previously by external beam radiotherapy with 54.4 Gy in 34 fractions twice daily, at least 6 h apart, within 3.5 weeks or 60 Gy in 30 fractions within 6 weeks. In addition, 84% had already received at least one chemotherapy regimen for recurrence. The median H-SRT dose at the 80% isodose was 25 Gy, and the maximal dose was 30 Gy delivered in five to six fractions on consecutive days. Topotecan (1.1 mg/m{sup 2}/d) was given as a continuous i.v. infusion during H-SRT. Depending on the toxicity and compliance, patients received an additional 48 topotecan courses. Results: For all patients, the actuarial median progression-free survival was 10.5 months (range, 1.4-47.8 months), the median functional survival was 12.6 months (range, 1.6-49.5 months), and the median overall survival was 14.5 months (range, 3-56.4 months). Twelve percent of patients developed presumed adverse radiation effects (Radiation Therapy Oncology Group Grade 2). According to the Common Toxicity Criteria, version 2.0, no topotecan-related Grade 4 toxicity was noted. Grade 3 neutropenia was documented after 14 and Grade 3 thrombopenia after 12 courses. Conclusion: H-SRT with topotecan is feasible and well-tolerated in patients with recurrent high-grade glioma and results in similar survival compared with other repeat treatment modalities.

  2. Prediction of AVM obliteration after stereotactic radiotherapy using radiobiological modelling.

    PubMed

    Mavroidis, Panayiotis; Theodorou, Kyriaki; Lefkopoulos, Dimitrios; Nataf, François; Schlienger, Michel; Karlsson, Bengt; Lax, Ingmar; Kappas, Constantin; Lind, Bengt K; Brahme, Anders

    2002-07-21

    This study was carried out in order to derive the radiobiological parameters of the dose-response relation for the obliteration of arteriovenous malformation (AVM) following single fraction stereotactic radiotherapy. Furthermore, the accuracy by which the linear Poisson model predicts the probability of obliteration and how the haemorrhage history, location and volume of the AVM influence its radiosensitivity are investigated. The study patient material consists of 85 patients who received radiation for AVM therapy. Radiation-induced AVM obliterations were assessed on the basis of post-irradiation angiographies and other radiological findings. For each patient the dose delivered to the clinical target volume and the clinical treatment outcome were available. These data were used in a maximum likelihood analysis to calculate the best estimates of the parameters of the linear Poisson model. The uncertainties of these parameters were also calculated and their individual influence on the dose-response curve was studied. AVM radiosensitivity was assumed to be the same for all the patients. The radiobiological model used was proved suitable for predicting the treatment outcome pattern of the studied patient material. The radiobiological parameters of the model were calculated for different AVM locations, bleeding histories and AVM sizes. The range of parameter variability had considerable effect on the dose-response curve of AVM. The correlation between the dosimetric data and their corresponding clinical effect could be accurately modelled using the linear Poisson model. The derived response parameters can be introduced into the clinical routine with the calculated accuracy assuming the same methodology in target definition and delineation. The known volume dependence of AVM radiosensitivity was confirmed. Moreover, a trend relating AVM location with its radiosensitivity was observed.

  3. Adjuvant Stereotactic Radiosurgery After Resection of Intracranial Hemangiopericytomas

    SciTech Connect

    Kano, Hideyuki; Niranjan, Ajay; Kondziolka, Douglas; Flickinger, John C.; Lunsford, L. Dade

    2008-12-01

    Purpose: To evaluate adjuvant stereotactic radiosurgery (SRS) in the management of recurrent or residual intracranial hemangiopericytomas (HPCs), we assessed tumor control, survival, and complications in patients who had undergone gamma knife SRS as part of multimodal therapy. Methods and Materials: We retrospectively reviewed the records of consecutive 20 HPC patients who had undergone SRS for 29 tumors. The median patient age was 51.5 years (range, 8.9-80.2). All patients had undergone previous surgical resection of their tumors. In addition, 12 patients underwent fractionated radiotherapy before SRS. Of the 20 patients, 16 patients had low-grade HPCs (20 tumors) and 4 had high-grade anaplastic HPCs (9 tumors). The median radiosurgery target volume was 4.5 cm{sup 3} (range, 0.07-34.3), and the median marginal dose was 15.0 Gy (range, 10-20). Results: At an average of 48.2 months (range, 7.2-124.1), 5 patients had died of metastases and 3 patients had died of disease progression. The overall survival after radiosurgery was 100%, 85.9%, and 13.8% at 1, 5, and 10 years, respectively. The follow-up imaging studies demonstrated tumor control in 21 (72.4%) of 29 tumors. The progression-free survival rate after SRS at 1, 3, and 5 years was 89.1% for low-grade HPCs and 88.9%, 66.7%, and 0%, respectively, for high-grade HPCs. The factors associated with improved progression-free survival included lower grade and higher marginal dose. Eight patients had intracranial or extracranial metastasis after the initial diagnosis, which correlated with the shorter survival. Conclusion: The results of our study have shown that adjuvant SRS after tumor resection is an important management option for patients with residual or recurrent HPCs and is particularly effective for less-aggressive tumors.

  4. Stereotactic Body Radiotherapy and Gemcitabine for Locally Advanced Pancreatic Cancer

    SciTech Connect

    Mahadevan, Anand; Jain, Sanjay; Goldstein, Michael; Miksad, Rebecca; Pleskow, Douglas; Sawhney, Mandeep; Brennan, Darren M.D.; Callery, Mark; Vollmer, Charles

    2010-11-01

    Purpose: Patients with nonmetastatic locally advanced unresectable pancreatic cancer have a dismal prognosis. Conventional concurrent chemoradiotherapy requires 6 weeks of daily treatment and can be arduous. We explored the safety and effectiveness of a 3-day course of hypofractionated stereotactic body radiotherapy (SBRT) followed by gemcitabine in this population. Patients and Methods: A total of 36 patients with nonmetastatic, locally advanced, unresectable pancreatic cancer with {>=}12 months of follow-up were included. They received three fractions of 8, 10, or 12 Gy (total dose, 24-36 Gy) of SBRT according to the tumor location in relation to the stomach and duodenum, using fiducial-based respiratory motion tracking on a robotic radiosurgery system. The patients were then offered gemcitabine for 6 months or until tolerance or disease progression. Results: With an overall median follow-up of 24 months (range, 12-33), the local control rate was 78%, the median overall survival time was 14.3 months, the median carbohydrate antigen 19-9-determined progression-free survival time was 7.9 months, and the median computed tomography-determined progression-free survival time was 9.6 months. Of the 36 patients, 28 (78%) eventually developed distant metastases. Six patients (17%) were free of progression at the last follow-up visit (range, 13-30 months) as determined by normalized tumor markers with stable computed tomography findings. Nine Grade 2 (25%) and five Grade 3 (14%) toxicities attributable to SBRT occurred. Conclusion: Hypofractionated SBRT can be delivered quickly and effectively in patients with nonmetastatic, locally advanced, unresectable pancreatic cancer with acceptable side effects and minimal interference with gemcitabine chemotherapy.

  5. Monitor Unit Checking in Heterogeneous Stereotactic Body Radiotherapy Treatment Planning

    SciTech Connect

    Higgins, Patrick D.; Adolfson, Troy; Cho, L. Chinsoo; Saxena, Rishik

    2011-10-01

    Treatment of lung cancer using very-high-dose fractionation in small fields requires well-tested dose modeling, a method for density-averaging compound targets constructed from different parts of the breathing cycle, and monitor unit verification of the heterogeneity-corrected treatment plans. The quality and safety of each procedure are dependent on these factors. We have evaluated the dosimetry of our first 26 stereotactic body radiotherapy (SBRT) patients, including 260 treatment fields, planned with the Pinnacle treatment planning system. All targets were combined from full expiration and inspiration computed tomography scans and planned on the normal respiration scan with 6-MV photons. Combined GTVs (cGTVs) have been density-averaged in different ways for comparison of the effect on total monitor units. In addition, we have compared planned monitor units against hand calculations using 2 classic 1D correction methods: (1) effective attenuation and (2) ratio of Tissue-Maximum Ratios (TMRs) to determine the range of efficacy of simple verification methods over difficult-to-perform measurements. Different methods of density averaging for combined targets have been found to have minimal impact on total dose as evidenced by the range of total monitor units generated for each method. Nondensity-corrected treatment plans for the same fields were found to require about 8% more monitor units on average. Hand calculations, using the effective attenuation method were found to agree with Pinnacle calculations for nonproblematic fields to within {+-}10% for >95% of the fields tested. The ratio of TMRs method was found to be unacceptable. Reasonable choices for density-averaging of cGTVs using full inspiration/expiration scans should not strongly affect the planning dose. Verification of planned monitor units, as a check for problematic fields, can be done for 6-MV fields with simple 1D effective attenuation-corrected hand calculations.

  6. 10 CFR 35.2645 - Records of periodic spot-checks for gamma stereotactic radiosurgery units.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Records of periodic spot-checks for gamma stereotactic... MATERIAL Records § 35.2645 Records of periodic spot-checks for gamma stereotactic radiosurgery units. (a) A... and intercom systems, timer termination, treatment table retraction mechanism, and stereotactic...

  7. 10 CFR 35.2645 - Records of periodic spot-checks for gamma stereotactic radiosurgery units.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Records of periodic spot-checks for gamma stereotactic... MATERIAL Records § 35.2645 Records of periodic spot-checks for gamma stereotactic radiosurgery units. (a) A... and intercom systems, timer termination, treatment table retraction mechanism, and stereotactic...

  8. Effects of combined sunitinib and extracranial stereotactic radiotherapy on bone marrow hematopoiesis

    PubMed Central

    Kao, Johnny; Timmins, Jonathan; Ozao-Choy, Junko; Packer, Stuart

    2016-01-01

    There is considerable interest in deploying stereotactic body radiotherapy in combination with immune therapy for patients with extracranial oligometastases. In addition to angiogenesis inhibition, sunitinib appears to mediate antitumor immunity through effects on circulating monocytic cells. The current study investigated the effects of combined sunitinib and stereotactic radiotherapy on hematopoiesis. As part of a phase I/II clinical trial utilizing concurrent sunitinib (25–50 mg on days 1–28) and image-guided radiation therapy (40–50 Gy in 10 fractions starting on days 8–19) for patients with metastatic cancer, the complete blood count, platelet count and automatic differential were performed pretreatment and on days 8 and 19. On average, sunitinib monotherapy for 7 days resulted in a 33% decrease in monocytes and an 18% decrease in neutrophils (P<0.01 for all). Compared to sunitinib alone, combined sunitinib and radiation resulted in a further decrease in neutrophils, lymphocytes and platelets (P<0.05). Following sunitinib and radiation treatment, a greater than average decrease in monocytes (≥200/µl) was associated with a significant increase in progression-free and overall survival times. This exploratory study provides further evidence that monocytes represent a potential biomarker in patients with solid tumors treated with sunitinib. PMID:27602153

  9. Survival and Quality of Life After Stereotactic or 3D-Conformal Radiotherapy for Inoperable Early-Stage Lung Cancer

    SciTech Connect

    Widder, Joachim; Postmus, Douwe; Ubbels, Jan F.; Wiegman, Erwin M.; Langendijk, Johannes A.

    2011-11-15

    Purpose: To investigate survival and local recurrence after stereotactic ablative radiotherapy (SABR) or three-dimensional conformal radiotherapy (3D-CRT) administered for early-stage primary lung cancer and to investigate longitudinal changes of health-related quality of life (HRQOL) parameters after either treatment. Methods and Materials: Two prospective cohorts of inoperable patients with T1-2N0M0 primary lung tumors were analyzed. Patients received 70 Gy in 35 fractions with 3D-CRT or 60 Gy in three to eight fractions with SABR. Global quality of life (GQOL), physical functioning (PF), and patient-rated dyspnea were assessed using the respective dimensions of European Organization for Research and Treatment of Cancer Core Questionnaire-C30 and LC13. HRQOL was analyzed using multivariate linear mixed-effects modeling, survival and local control (LC) using the Kaplan-Meier method, Cox proportional hazards analysis, and Fine and Gray multivariate competing risk analysis as appropriate. Results: Overall survival (OS) was better after SABR compared with 3D-CRT with a HR of 2.6 (95% confidence interval [CI]: 1.5-4.8; p < 0.01). 3D-CRT conferred a subhazard ratio for LC of 5.0 (95% CI: 1.7-14.7; p < 0.01) compared with SABR. GQOL and PF were stable after SABR (p = 0.21 and p = 0.62, respectively). Dyspnea increased after SABR by 3.2 out of 100 points (95% CI: 1.0-5.3; p < 0.01), which is clinically insignificant. At 1 year, PF decreased by an excess of 8.7 out of 100 points (95% CI: 2.8-14.7; p < 0.01) after 3D-CRT compared with SABR. Conclusion: In this nonrandomized comparison of two prospective cohorts of medically inoperable patients with Stage I lung cancer, OS and LC were better after SABR. GQOL, PF, and patient-rated dyspnea were stable after SABR, whereas PF decreased after 3D-CRT approaching clinical significance already at 1 year.

  10. Stereotactic Body Radiation Therapy for Locally Advanced and Borderline Resectable Pancreatic Cancer Is Effective and Well Tolerated

    SciTech Connect

    Chuong, Michael D.; Springett, Gregory M.; Freilich, Jessica M.; Park, Catherine K.; Weber, Jill M.; Mellon, Eric A.; Hodul, Pamela J.; Malafa, Mokenge P.; Meredith, Kenneth L.; Hoffe, Sarah E.; Shridhar, Ravi

    2013-07-01

    Purpose: Stereotactic body radiation therapy (SBRT) provides high rates of local control (LC) and margin-negative (R0) resections for locally advanced pancreatic cancer (LAPC) and borderline resectable pancreatic cancer (BRPC), respectively, with minimal toxicity. Methods and Materials: A single-institution retrospective review was performed for patients with nonmetastatic pancreatic cancer treated with induction chemotherapy followed by SBRT. SBRT was delivered over 5 consecutive fractions using a dose painting technique including 7-10 Gy/fraction to the region of vessel abutment or encasement and 5-6 Gy/fraction to the remainder of the tumor. Restaging scans were performed at 4 weeks, and resectable patients were considered for resection. The primary endpoints were overall survival (OS) and progression-free survival (PFS). Results: Seventy-three patients were evaluated, with a median follow-up time of 10.5 months. Median doses of 35 Gy and 25 Gy were delivered to the region of vessel involvement and the remainder of the tumor, respectively. Thirty-two BRPC patients (56.1%) underwent surgery, with 31 undergoing an R0 resection (96.9%). The median OS, 1-year OS, median PFS, and 1-year PFS for BRPC versus LAPC patients was 16.4 months versus 15 months, 72.2% versus 68.1%, 9.7 versus 9.8 months, and 42.8% versus 41%, respectively (all P>.10). BRPC patients who underwent R0 resection had improved median OS (19.3 vs 12.3 months; P=.03), 1-year OS (84.2% vs 58.3%; P=.03), and 1-year PFS (56.5% vs 25.0%; P<.0001), respectively, compared with all nonsurgical patients. The 1-year LC in nonsurgical patients was 81%. We did not observe acute grade ≥3 toxicity, and late grade ≥3 toxicity was minimal (5.3%). Conclusions: SBRT safely facilitates margin-negative resection in patients with BRPC pancreatic cancer while maintaining a high rate of LC in unresectable patients. These data support the expanded implementation of SBRT for pancreatic cancer.

  11. Stereotactic Radiotherapy for Unilateral Orbital Lymphoma and Orbital Pseudo-Tumors: A Planning Study

    SciTech Connect

    Chino, Kazumi Tanyi, James A.; Stea, Baldassarre

    2009-04-01

    Orbital lymphoma and Grave's ophthalmopathy (GO) are successfully treated with radiation therapy. The lenses are blocked to prevent cataract formation. However, blocking of the lens by traditional methods can be difficult for tumors located anteriorly and extending into the retrobulbar space. We present a series of 3 patients with orbital lymphoma and 1 with GO treated with stereotactic intensity modulated radiation therapy (IMRT) to spare normal structures, including the lens. Three patients with orbital lymphomas and 1 with unilateral GO were treated with IMRT using a linac with stereotactic capabilities. Avoidance structures included the ipsilateral lens and globe, the contralateral lens and globe, the chiasm, and the brainstem. Two patients with orbital lymphoma were treated with 24 Gy in 12 fractions, and 1 patient was treated with 30.6 Gy in 17 fractions. The patient with GO was treated with 20 Gy in 10 fractions. The dosimetry was analyzed to determine the dose to normal tissues. Patient follow-up varies between 8 and 24 months. The mean minimal dose to the ipsilateral lens was 13.6% of the total dose, the mean maximal dose was 33.5%, and the mean median dose was 19.3%. The mean median dose to the contralateral eye was 1.1% of the total dose. The mean median dose to the chiasm was 14.9% of the total dose. The mean median dose to the brainstem was 1.9% of the total dose. No cataracts or other complications were noted in the 4 patients treated with this technique so far. IMRT gives a more conformal treatment to the orbital contents while sparing normal tissues such as the ipsilateral lens and adjacent critical structures. This should result in fewer complications such as cataracts.

  12. Effect of image-guided hypofractionated stereotactic radiotherapy on peripheral non-small-cell lung cancer

    PubMed Central

    Wang, Shu-wen; Ren, Juan; Yan, Yan-li; Xue, Chao-fan; Tan, Li; Ma, Xiao-wei

    2016-01-01

    The objective of this study was to compare the effects of image-guided hypofractionated radiotherapy and conventional fractionated radiotherapy on non-small-cell lung cancer (NSCLC). Fifty stage- and age-matched cases with NSCLC were randomly divided into two groups (A and B). There were 23 cases in group A and 27 cases in group B. Image-guided radiotherapy (IGRT) and stereotactic radiotherapy were conjugately applied to the patients in group A. Group A patients underwent hypofractionated radiotherapy (6–8 Gy/time) three times per week, with a total dose of 64–66 Gy; group B received conventional fractionated radiotherapy, with a total dose of 68–70 Gy five times per week. In group A, 1-year and 2-year local failure survival rate and 1-year local failure-free survival rate were significantly higher than in group B (P<0.05). The local failure rate (P<0.05) and distant metastasis rate (P>0.05) were lower in group A than in group B. The overall survival rate of group A was significantly higher than that of group B (P=0.03), and the survival rate at 1 year was 87% vs 63%, (P<0.05). The median survival time of group A was longer than that of group B. There was no significant difference in the incidence of complications between the two groups (P>0.05). Compared with conventional fractionated radiation therapy, image-guided hypofractionated stereotactic radiotherapy in NSCLC received better treatment efficacy and showed good tolerability. PMID:27574441

  13. Outcomes for Spine Stereotactic Body Radiation Therapy and an Analysis of Predictors of Local Recurrence

    SciTech Connect

    Bishop, Andrew J.; Tao, Randa; Rebueno, Neal C.; Christensen, Eva N.; Allen, Pamela K.; Wang, Xin A.; Amini, Behrang; Tannir, Nizar M.; Tatsui, Claudio E.; Rhines, Laurence D.; Li, Jing; Chang, Eric L.; Brown, Paul D.; Ghia, Amol J.

    2015-08-01

    Purpose: To investigate local control, survival outcomes, and predictors of local relapse for patients treated with spine stereotactic body radiation therapy. Methods and Materials: We reviewed the records of 332 spinal metastases consecutively treated with stereotactic body radiation therapy between 2002 and 2012. The median follow-up for all living patients was 33 months (range, 0-111 months). Endpoints were overall survival and local control (LC); recurrences were classified as either in-field or marginal. Results: The 1-year actuarial LC and overall survival rates were 88% and 64%, respectively. Patients with local relapses had poorer dosimetric coverage of the gross tumor volume (GTV) compared with patients without recurrence (minimum dose [Dmin] biologically equivalent dose [BED] 23.9 vs 35.1 Gy, P<.001; D98 BED 41.8 vs 48.1 Gy, P=.001; D95 BED 47.2 vs 50.5 Gy, P=.004). Furthermore, patients with marginal recurrences had poorer prescription coverage of the GTV (86% vs 93%, P=.01) compared with those with in-field recurrences, potentially because of more upfront spinal canal disease (78% vs 24%, P=.001). Using a Cox regression univariate analysis, patients with a GTV BED Dmin ≥33.4 Gy (median dose) (equivalent to 14 Gy in 1 fraction) had a significantly higher 1-year LC rate (94% vs 80%, P=.001) compared with patients with a lower GTV BED Dmin; this factor was the only significant variable on multivariate Cox analysis associated with LC (P=.001, hazard ratio 0.29, 95% confidence interval 0.14-0.60) and also was the only variable significant in a separate competing risk multivariate model (P=.001, hazard ratio 0.30, 95% confidence interval 0.15-0.62). Conclusions: Stereotactic body radiation therapy offers durable control for spinal metastases, but there is a subset of patients that recur locally. Patients with local relapse had significantly poorer tumor coverage, which was likely attributable to treatment planning directives that prioritized the

  14. Radiogenic Side Effects After Hypofractionated Stereotactic Photon Radiotherapy of Choroidal Melanoma in 212 Patients Treated Between 1997 and 2007

    SciTech Connect

    Dunavoelgyi, Roman; Dieckmann, Karin; Gleiss, Andreas; Sacu, Stefan; Kircher, Karl; Georgopoulos, Michael; Georg, Dietmar; Zehetmayer, Martin; Poetter, Richard

    2012-05-01

    Purpose: To evaluate side effects of hypofractionated stereotactic photon radiotherapy for patients with choroidal melanoma. Patients and Methods: Two hundred and twelve patients with choroidal melanoma unsuitable for ruthenium-106 brachytherapy or local resection were treated stereotactically at the Medical University of Vienna between 1997 and 2007 with a Linac with 6-MV photon beams in five fractions with 10, 12, or 14 Gy per fraction. Examinations for radiogenic side effects were performed at baseline and every 3 months in the first 2 years, then every 6 months until 5 years and then once a year thereafter until 10 years after radiotherapy. Adverse side effects were assessed using slit-lamp examination, funduscopy, gonioscopy, tonometry, and, if necessary, fundus photography and fluorescein angiography. Evaluations of incidence of side effects are based on an actuarial analysis. Results: One hundred and eighty-nine (89.2%) and 168 (79.2%) of the tumors were within 3 mm of the macula and the optic disc, respectively. The five most common radiotherapy side effects were retinopathy and optic neuropathy (114 cases and 107 cases, respectively), cataract development (87 cases), neovascular glaucoma (46 cases), and corneal epithelium defects (41 cases). In total, 33.6%, 38.5%, 51.2%, 75.5%, and 77.6% of the patients were free of any radiation retinopathy, optic neuropathy, cataract, neovascular glaucoma, or corneal epithelium defects 5 years after radiotherapy, respectively. Conclusion: In centrally located choroidal melanoma hypofractionated stereotactic photon radiotherapy shows a low to moderate rate of adverse long-term side effects comparable with those after proton beam radiotherapy. Future fractionation schemes should seek to further reduce adverse side effects rate while maintaining excellent local tumor control.

  15. STOCK AND DISTRIBUTION OF TOTAL AND CORN-DERIVED SOIL ORGANIC CARBON IN AGGREGATE AND PRIMARY PARTICLE FRACTIONS FOR DIFFERENT LAND USE AND SOIL MANAGEMENT PRACTICES

    SciTech Connect

    Puget, P; Lal, Rattan; Izaurralde, R Cesar C.; Post, M; Owens, Lloyd

    2005-04-01

    Land use, soil management, and cropping systems affect stock, distribution, and residence time of soil organic carbon (SOC). Therefore, SOC stock and its depth distribution and association with primary and secondary particles were assessed in long-term experiments at the North Appalachian Experimental Watersheds near Coshocton, Ohio, through *13C techniques. These measurements were made for five land use and soil management treatments: (1) secondary forest, (2) meadow converted from no-till (NT) corn since 1988, (3) continuous NT corn since 1970, (4) continuous NT corn-soybean in rotation with ryegrass since 1984, and (5) conventional plow till (PT) corn since 1984. Soil samples to 70-cm depth were obtained in 2002 in all treatments. Significant differences in soil properties were observed among land use treatments for 0 to 5-cm depth. The SOC concentration (g C kg*1 of soil) in the 0 to 5-cm layer was 44.0 in forest, 24.0 in meadow, 26.1 in NT corn, 19.5 in NT corn-soybean, and 11.1 i n PT corn. The fraction of total C in corn residue converted to SOC was 11.9% for NT corn, 10.6% for NT corn-soybean, and 8.3% for PT corn. The proportion of SOC derived from corn residue was 96% for NT corn in the 0 to 5-cm layer, and it decreased gradually with depth and was 50% in PT corn. The mean SOC sequestration rate on conversion from PT to NT was 280 kg C ha*1 y*1. The SOC concentration decreased with reduction in aggregate size, and macro-aggregates contained 15 to 35% more SOC concentration than microaggregates. In comparison with forest, the magnitude of SOC depletion in the 0 to 30-cm layer was 15.5 Mg C/ha (24.0%) in meadow, 12.7 Mg C/ha (19.8%) in NT corn, 17.3 Mg C/ha (26.8%) in NT corn-soybean, and 23.3 Mg C/ha (35.1%) in PT corn. The SOC had a long turnover time when located deeper in the subsoil.

  16. Role of stereotactic radiosurgery with a linear accelerator in treatment of intracranial arteriovenous malformations and tumors in children.

    PubMed

    Loeffler, J S; Rossitch, E; Siddon, R; Moore, M R; Rockoff, M A; Alexander, E

    1990-05-01

    Between 1986 and 1988, 16 children were treated for 10 arteriovenous malformations and 6 recurrent intracranial tumors with stereotactic radiation therapy using a modified Clinac 6/100 linear accelerator. The median age of our patients was 10.5 years. For the group with arteriovenous malformation, follow-up ranged from 6 months to 37 months (median was 20 months). No patient bled during the follow-up period. Five of eight patients with follow-up longer than 12 months have achieved complete obliteration of their arteriovenous malformation by angiogram. The four remaining patients who have not achieved a complete obliteration are awaiting their 2-year posttreatment angiogram. The other patient has been treated within the year and have not yet been studied. Five of the six recurrent tumor patients are alive with a median follow-up of 8 months. The remaining patient was controlled locally, but he died of recurrent disease outside the area treated with radiosurgery. The radiographic responses of these patients have included three complete responses, two substantial reductions in tumor volume (greater than 50%) and one stabilization. Despite previous radiotherapy, there have been no significant complications in these patients. We conclude that stereotactic radiation therapy using a standard linear accelerator is an effective and safe technique in the treatment of selected intracranial arteriovenous malformations and tumors in children. In addition, stereotactic radiosurgery may have unique applications in the treatment of localized primary and recurrent pediatric brain tumors.

  17. A new system for neuronavigation and stereotactic biopsy pantograph stereotactic localization and guidance system.

    PubMed

    Abrishamkar, Saeid; Moin, Houshang; Safavi, Mohammadreza; Honarmand, Azim; Hajibabaie, Mahmood; Haghighi, Elham K; Abbasifard, Salman

    2011-07-01

    Everyday, neurosurgeons face the problem of orientation within the brain but the advent of stereotactic surgery and neuronavigation have solved this problem. Frame-based stereotactic systems (FBSS) and neuronavigation systems have their own strengths and priority and pitfalls, which were the main driving force for us to design a new system. This hybrid system comprises three main parts: main frame, monitoring system, and pantograph, which are connected to each other and to the operating table by particular attachments. For using this system, after performing CT SCAN or Magnetic Resonance Imaging (MRI) the axial view will be transferred to Liquid Cristal Display (LCD). In the operating room, the head of the patient fixes to the operating table and registration is completed by two arms of pantograph. We made a simulation operation with our system on an occipital cavernous angioma and a frontal oligodendroglioma. The software, which have been used for simulation were as follows; Poser (version-7), Catia (version 5- R18), and 3 Dimension Max (version 2008). The accuracy of this system is approximately two millimeter. The advantages of this system are: easy to use, much less expensive, and compatible with different devices, which may be needed during neurosurgical operation. For countries that do not have the opportunity to have sophisticated technology and neuronavigation system, we believe that our system is a one-stop solution.

  18. Stereotactic Radiofrequency Ablation of Unresectable Intrahepatic Cholangiocarcinomas: A Retrospective Study

    SciTech Connect

    Haidu, Marion; Dobrozemsky, Georg; Schullian, Peter Widmann, Gerlig; Klaus, Alexander Weiss, Helmut Margreiter, Raimund; Bale, Reto

    2012-10-15

    Purpose: To evaluate treatment effects, complications, and outcome of percutaneous stereotactic radiofrequency ablation (SRFA) of intrahepatic cholangiocarcinoma (ICC). Patients and Methods: Eleven consecutive patients (nine men and two women) with a total of 36 inoperable ICCs (18 initial lesions, 16 lesions newly detected during follow-up, and two local recurrences) underwent SRFA between December 2004 and June 2010. Two different radiofrequency ablation (RFA) devices with internally cooled electrodes were used. Tumor diameters ranged from 0.5 to 10 cm (median 3.0 cm). A total of 23 SRFA sessions were performed. The efficacy of SRFA was evaluated by contrast-enhanced computed tomography or magnetic resonance imaging 1 month after treatment and then every 3 months. Results: Primary technical effectiveness rate was 92%. Further follow-up every 3 months revealed three local recurrences (8%), two of which were successfully retreated, resulting in a secondary technical effectiveness rate of 98%. After a total of 23 RFA sessions, three major complications occurred (13%) that could be managed interventionally. Mean follow-up time was 35 months (range 12-81 months). One- and 3-year overall survival rates were 91 and 71%, respectively. The median overall survival was 60 months (according to the life table method). Eight (73%) of 11 patients were still alive at the end of follow-up. Conclusion: SRFA is effective in the treatment of unresectable ICC even if the tumor is large and located close to major vessels. SRFA shows a survival benefit compared to other palliative treatment options and may also be considered as the first-line local treatment of ICCs in selected patients.

  19. Stereotactic radiosurgery of brain metastasis from melanoma.

    PubMed

    Marchan, Edward M; Sheehan, Jason

    2012-01-01

    Brain metastasis represents the most common intracranial neoplasm in adult patients. Melanoma is the third most frequent cancer histology and consequently comprises a significant portion of brain metastasis patients. Unlike the more frequent lung and breast cancers, melanoma represents a particularly challenging entity because of its radioresistant nature. Stereotactic radiosurgery appears to overcome the inherent radioresistance of brain metastasis from melanoma and, thereby, affords a high rate of local tumor control. Reports from leading centers indicate a favorable benefit to risk profile for radiosurgery in melanoma patients. Local tumor control after radiosurgery generally exceeds 80%, and neurological complications as a result of radiosurgery are infrequent. A higher performance status and lower intracranial tumor burden in melanoma patients at the time of radiosurgery are associated with longer survival. Radiosurgery may be used in conjunction upfront with radiotherapy, resection, and chemotherapy or as a salvage therapy in selected melanoma patients. Careful radiological and neurological follow-up is required to assess local tumor control and distant intracranial disease progression. Further clinical studies will be required to better define the role of upfront and salvage radiosurgery in selected cohorts of patients with brain metastasis from melanoma. However, it appears likely that radiosurgery will play an expanded role in the overall management of these patients.

  20. Optical Tracking Technology in Stereotactic Radiation Therapy

    SciTech Connect

    Wagner, Thomas H. . E-mail: thomas.wagner@orhs.org; Meeks, Sanford L.; Bova, Frank J.; Friedman, William A.; Willoughby, Twyla R.; Kupelian, Patrick A.; Tome, Wolfgang

    2007-07-01

    The last decade has seen the introduction of advanced technologies that have enabled much more precise application of therapeutic radiation. These relatively new technologies include multileaf collimators, 3-dimensional conformal radiotherapy planning, and intensity modulated radiotherapy in radiotherapy. Therapeutic dose distributions have become more conformal to volumes of disease, sometimes utilizing sharp dose gradients to deliver high doses to target volumes while sparing nearby radiosensitive structures. Thus, accurate patient positioning has become even more important, so that the treatment delivered to the patient matches the virtual treatment plan in the computer treatment planning system. Optical and image-guided radiation therapy systems offer the potential to improve the precision of patient treatment by providing a more robust fiducial system than is typically used in conventional radiotherapy. The ability to accurately position internal targets relative to the linac isocenter and to provide real-time patient tracking theoretically enables significant reductions in the amount of normal tissue irradiated. This report reviews the concepts, technology, and clinical applications of optical tracking systems currently in use for stereotactic radiation therapy. Applications of radiotherapy optical tracking technology to respiratory gating and the monitoring of implanted fiducial markers are also discussed.

  1. Stereotactic CO2 laser therapy for hydrocephalus

    NASA Astrophysics Data System (ADS)

    Kozodoy-Pins, Rebecca L.; Harrington, James A.; Zazanis, George A.; Nosko, Michael G.; Lehman, Richard M.

    1994-05-01

    A new fiber-optic delivery system for CO2 radiation has been used to successfully treat non-communicating hydrocephalus. This system consists of a hollow sapphire waveguide employed in the lumen of a stereotactically-guided neuroendoscope. CO2 gas flows through the bore of the hollow waveguide, creating a path for the laser beam through the cerebrospinal fluid (CSF). This delivery system has the advantages of both visualization and guided CO2 laser radiation without the same 4.3 mm diameter scope. Several patients with hydrocephalus were treated with this new system. The laser was used to create a passage in the floor of the ventricle to allow the flow of CSF from the ventricles to the sub-arachnoid space. Initial postoperative results demonstrated a relief of the clinical symptoms. Long-term results will indicate if this type of therapy will be superior to the use of implanted silicone shunts. Since CO2 laser radiation at 10.6 micrometers is strongly absorbed by the water in tissue and CSF, damage to tissue surrounding the lesion with each laser pulse is limited. The accuracy and safety of this technique may prove it to be an advantageous therapy for obstructive hydrocephalus.

  2. Repeat Stereotactic Radiosurgery for Acoustic Neuromas

    SciTech Connect

    Kano, Hideyuki; Kondziolka, Douglas; Niranjan, Ajay M.Ch.; Flannery, Thomas J.; Flickinger, John C.; Lunsford, L. Dade

    2010-02-01

    Purpose: To evaluate the outcome of repeat stereotactic radiosurgery (SRS) for acoustic neuromas, we assessed tumor control, clinical outcomes, and the risk of adverse radiation effects in patients whose tumors progressed after initial management. Methods and Materials: During a 21-year experience at our center, 1,352 patients underwent SRS as management for their acoustic neuromas. We retrospectively identified 6 patients who underwent SRS twice for the same tumor. The median patient age was 47 years (range, 35-71 years). All patients had imaging evidence of tumor progression despite initial SRS. One patient also had incomplete surgical resection after initial SRS. All patients were deaf at the time of the second SRS. The median radiosurgery target volume at the time of the initial SRS was 0.5 cc and was 2.1 cc at the time of the second SRS. The median margin dose at the time of the initial SRS was 13 Gy and was 11 Gy at the time of the second SRS. The median interval between initial SRS and repeat SRS was 63 months (range, 25-169 months). Results: At a median follow-up of 29 months after the second SRS (range, 13-71 months), tumor control or regression was achieved in all 6 patients. No patient developed symptomatic adverse radiation effects or new neurological symptoms after the second SRS. Conclusions: With this limited experience, we found that repeat SRS for a persistently enlarging acoustic neuroma can be performed safely and effectively.

  3. Reirradiation Human Spinal Cord Tolerance for Stereotactic Body Radiotherapy

    SciTech Connect

    Sahgal, Arjun; Ma, Lijun; Weinberg, Vivian; Gibbs, Iris C.; Chao, Sam; Chang, Ung-Kyu; Werner-Wasik, Maria; Angelov, Liliyanna; Chang, Eric L.; Sohn, Moon-Jun; Soltys, Scott G.; Letourneau, Daniel; Ryu, Sam; Gerszten, Peter C.; Fowler, Jack; Wong, C. Shun; and others

    2012-01-01

    Purpose: We reviewed the treatment for patients with spine metastases who initially received conventional external beam radiation (EBRT) and were reirradiated with 1-5 fractions of stereotactic body radiotherapy (SBRT) who did or did not subsequently develop radiation myelopathy (RM). Methods and Materials: Spinal cord dose-volume histograms (DVHs) for 5 RM patients (5 spinal segments) and 14 no-RM patients (16 spine segments) were based on thecal sac contours at retreatment. Dose to a point within the thecal sac that receives the maximum dose (P{sub max}), and doses to 0.1-, 1.0-, and 2.0-cc volumes within the thecal sac were reviewed. The biologically effective doses (BED) using {alpha}/{beta} = 2 Gy for late spinal cord toxicity were calculated and normalized to a 2-Gy equivalent dose (nBED = Gy{sub 2/2}). Results: The initial conventional radiotherapy nBED ranged from {approx}30 to 50 Gy{sub 2/2} (median {approx}40 Gy{sub 2/2}). The SBRT reirradiation thecal sac mean P{sub max} nBED in the no-RM group was 20.0 Gy{sub 2/2} (95% confidence interval [CI], 10.8-29.2), which was significantly lower than the corresponding 67.4 Gy{sub 2/2} (95% CI, 51.0-83.9) in the RM group. The mean total P{sub max} nBED in the no-RM group was 62.3 Gy{sub 2/2} (95% CI, 50.3-74.3), which was significantly lower than the corresponding 105.8 Gy{sub 2/2} (95% CI, 84.3-127.4) in the RM group. The fraction of the total P{sub max} nBED accounted for by the SBRT P{sub max} nBED for the RM patients ranged from 0.54 to 0.78 and that for the no-RM patients ranged from 0.04 to 0.53. Conclusions: SBRT given at least 5 months after conventional palliative radiotherapy with a reirradiation thecal sac P{sub max} nBED of 20-25 Gy{sub 2/2} appears to be safe provided the total P{sub max} nBED does not exceed approximately 70 Gy{sub 2/2}, and the SBRT thecal sac P{sub max} nBED comprises no more than approximately 50% of the total nBED.

  4. Stereotactic radiosurgery using the Leksell Gamma Knife: current trends and future directives.

    PubMed

    Jawahar, Ajay; Jawahar, Lisa L; Nanda, Anil; Sharp, Christopher D; Warren, April; Elrod, John W; Jennings, Merilyn; Alexander, J Steven; Minagar, Alireza

    2004-01-01

    Stereotactic radiosurgery is the extremely precise administration of a radiation dosage in three-dimensional space to treat an increasingly broad spectrum of intracranial and skull-base lesions. 455 patients with various indications were treated using the 201 Source Co-60 Leksell Model "B" Gamma Knife(r) at Louisiana State University Health Sciences Center in Shreveport, Louisiana. 273 (60.2%) patients received radiosurgery as the first line of treatment for their disease. The mean Karnofsky Performance Score (KPS) of the patients was 70. Cerebral metastases were the main indications for radiosurgery at our center accounting for 27% of the patients, while meningioma, AVM, trigeminal neuralgia, movement disorders, and primary CNS malignant tumors were the other indications. Our institutional experience and results indicate that low incidence of complications coupled with a high tumor control rate makes Gamma Knife stereotactic radiosurgery a viable option for patients who must undergo neurosurgery. As the Gamma Knife continues to prove itself as a first-line treatment of many complex brain disorders, new indications for this technology will continue to emerge, further broadening the scope of patient care.

  5. Effect of radiation protraction on BED in the case of large fraction dose

    SciTech Connect

    Kuperman, V. Y.

    2013-08-15

    Purpose: To investigate the effect of radiation protraction on biologically effective dose (BED) in the case when dose per fraction is significantly greater than the standard dose of 2 Gy.Methods: By using the modified linear-quadratic model with monoexponential repair, the authors investigate the effect of long treatment times combined with dose escalation.Results: The dependences of the protraction factor and the corresponding BED on fraction time were determined for different doses per fraction typical for stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT). In the calculations, the authors consider changes in the BED to the normal tissue under the condition of fixed BED to the target.Conclusion: The obtained results demonstrate that simultaneous increase in fraction time and dose per fraction can be beneficial for SRS and SBRT because of the related decrease in BED to normal structures while BED to the target is fixed.

  6. Indirect Tumor Cell Death After High-Dose Hypofractionated Irradiation: Implications for Stereotactic Body Radiation Therapy and Stereotactic Radiation Surgery

    SciTech Connect

    Song, Chang W.; Lee, Yoon-Jin; Griffin, Robert J.; Park, Inhwan; Koonce, Nathan A.; Hui, Susanta; Kim, Mi-Sook; Dusenbery, Kathryn E.; Sperduto, Paul W.; Cho, L. Chinsoo

    2015-09-01

    Purpose: The purpose of this study was to reveal the biological mechanisms underlying stereotactic body radiation therapy (SBRT) and stereotactic radiation surgery (SRS). Methods and Materials: FSaII fibrosarcomas grown subcutaneously in the hind limbs of C3H mice were irradiated with 10 to 30 Gy of X rays in a single fraction, and the clonogenic cell survival was determined with in vivo–in vitro excision assay immediately or 2 to 5 days after irradiation. The effects of radiation on the intratumor microenvironment were studied using immunohistochemical methods. Results: After cells were irradiated with 15 or 20 Gy, cell survival in FSaII tumors declined for 2 to 3 days and began to recover thereafter in some but not all tumors. After irradiation with 30 Gy, cell survival declined continuously for 5 days. Cell survival in some tumors 5 days after 20 to 30 Gy irradiation was 2 to 3 logs less than that immediately after irradiation. Irradiation with 20 Gy markedly reduced blood perfusion, upregulated HIF-1α, and increased carbonic anhydrase-9 expression, indicating that irradiation increased tumor hypoxia. In addition, expression of VEGF also increased in the tumor tissue after 20 Gy irradiation, probably due to the increase in HIF-1α activity. Conclusions: Irradiation of FSaII tumors with 15 to 30 Gy in a single dose caused dose-dependent secondary cell death, most likely by causing vascular damage accompanied by deterioration of intratumor microenvironment. Such indirect tumor cell death may play a crucial role in the control of human tumors with SBRT and SRS.

  7. First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV.

    PubMed

    Aguilar, M; Alberti, G; Alpat, B; Alvino, A; Ambrosi, G; Andeen, K; Anderhub, H; Arruda, L; Azzarello, P; Bachlechner, A; Barao, F; Baret, B; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Basili, A; Batalha, L; Bates, J; Battiston, R; Bazo, J; Becker, R; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Berges, P; Bertucci, B; Bigongiari, G; Biland, A; Bindi, V; Bizzaglia, S; Boella, G; de Boer, W; Bollweg, K; Bolmont, J; Borgia, B; Borsini, S; Boschini, M J; Boudoul, G; Bourquin, M; Brun, P; Buénerd, M; Burger, J; Burger, W; Cadoux, F; Cai, X D; Capell, M; Casadei, D; Casaus, J; Cascioli, V; Castellini, G; Cernuda, I; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, C R; Chen, H; Cheng, G M; Chen, H S; Cheng, L; Chernoplyiokov, N; Chikanian, A; Choumilov, E; Choutko, V; Chung, C H; Clark, C; Clavero, R; Coignet, G; Commichau, V; Consolandi, C; Contin, A; Corti, C; Costado Dios, M T; Coste, B; Crespo, D; Cui, Z; Dai, M; Delgado, C; Della Torre, S; Demirkoz, B; Dennett, P; Derome, L; Di Falco, S; Diao, X H; Diago, A; Djambazov, L; Díaz, C; von Doetinchem, P; Du, W J; Dubois, J M; Duperay, R; Duranti, M; D'Urso, D; Egorov, A; Eline, A; Eppling, F J; Eronen, T; van Es, J; Esser, H; Falvard, A; Fiandrini, E; Fiasson, A; Finch, E; Fisher, P; Flood, K; Foglio, R; Fohey, M; Fopp, S; Fouque, N; Galaktionov, Y; Gallilee, M; Gallin-Martel, L; Gallucci, G; García, B; García, J; García-López, R; García-Tabares, L; Gargiulo, C; Gast, H; Gebauer, I; Gentile, S; Gervasi, M; Gillard, W; Giovacchini, F; Girard, L; Goglov, P; Gong, J; Goy-Henningsen, C; Grandi, D; Graziani, M; Grechko, A; Gross, A; Guerri, I; de la Guía, C; Guo, K H; Habiby, M; Haino, S; Hauler, F; He, Z H; Heil, M; Heilig, J; Hermel, R; Hofer, H; Huang, Z C; Hungerford, W; Incagli, M; Ionica, M; Jacholkowska, A; Jang, W Y; Jinchi, H; Jongmanns, M; Journet, L; Jungermann, L; Karpinski, W; Kim, G N; Kim, K S; Kirn, Th; Kossakowski, R; Koulemzine, A; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M S; Laudi, E; Laurenti, G; Lauritzen, C; Lebedev, A; Lee, M W; Lee, S C; Leluc, C; León Vargas, H; Lepareur, V; Li, J Q; Li, Q; Li, T X; Li, W; Li, Z H; Lipari, P; Lin, C H; Liu, D; Liu, H; Lomtadze, T; Lu, Y S; Lucidi, S; Lübelsmeyer, K; Luo, J Z; Lustermann, W; Lv, S; Madsen, J; Majka, R; Malinin, A; Mañá, C; Marín, J; Martin, T; Martínez, G; Masciocchi, F; Masi, N; Maurin, D; McInturff, A; McIntyre, P; Menchaca-Rocha, A; Meng, Q; Menichelli, M; Mereu, I; Millinger, M; Mo, D C; Molina, M; Mott, P; Mujunen, A; Natale, S; Nemeth, P; Ni, J Q; Nikonov, N; Nozzoli, F; Nunes, P; Obermeier, A; Oh, S; Oliva, A; Palmonari, F; Palomares, C; Paniccia, M; Papi, A; Park, W H; Pauluzzi, M; Pauss, F; Pauw, A; Pedreschi, E; Pensotti, S; Pereira, R; Perrin, E; Pessina, G; Pierschel, G; Pilo, F; Piluso, A; Pizzolotto, C; Plyaskin, V; Pochon, J; Pohl, M; Poireau, V; Porter, S; Pouxe, J; Putze, A; Quadrani, L; Qi, X N; Rancoita, P G; Rapin, D; Ren, Z L; Ricol, J S; Riihonen, E; Rodríguez, I; Roeser, U; Rosier-Lees, S; Rossi, L; Rozhkov, A; Rozza, D; Sabellek, A; Sagdeev, R; Sandweiss, J; Santos, B; Saouter, P; Sarchioni, M; Schael, S; Schinzel, D; Schmanau, M; Schwering, G; Schulz von Dratzig, A; Scolieri, G; Seo, E S; Shan, B S; Shi, J Y; Shi, Y M; Siedenburg, T; Siedling, R; Son, D; Spada, F; Spinella, F; Steuer, M; Stiff, K; Sun, W; Sun, W H; Sun, X H; Tacconi, M; Tang, C P; Tang, X W; Tang, Z C; Tao, L; Tassan-Viol, J; Ting, Samuel C C; Ting, S M; Titus, C; Tomassetti, N; Toral, F; Torsti, J; Tsai, J R; Tutt, J C; Ulbricht, J; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vargas Trevino, M; Vaurynovich, S; Vecchi, M; Vergain, M; Verlaat, B; Vescovi, C; Vialle, J P; Viertel, G; Volpini, G; Wang, D; Wang, N H; Wang, Q L; Wang, R S; Wang, X; Wang, Z X; Wallraff, W; Weng, Z L; Willenbrock, M; Wlochal, M; Wu, H; Wu, K Y; Wu, Z S; Xiao, W J; Xie, S; Xiong, R Q; Xin, G M; Xu, N S; Xu, W; Yan, Q; Yang, J; Yang, M; Ye, Q H; Yi, H; Yu, Y J; Yu, Z Q; Zeissler, S; Zhang, J G; Zhang, Z; Zhang, M M; Zheng, Z M; Zhuang, H L; Zhukov, V; Zichichi, A; Zuccon, P; Zurbach, C

    2013-04-05

    A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250  GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

  8. Stereotactic radiosurgery for a cardiac sarcoma: a case report.

    PubMed

    Soltys, Scott G; Kalani, M Yashar S; Cheshier, Samuel H; Szabo, Katalin A; Lo, Anthony; Chang, Steven D

    2008-10-01

    Pulmonary artery intimal sarcoma is an uncommon tumor with a poor prognosis. We report a case of a 75-year-old man with a pulmonary artery sarcoma, recurrent following surgical resection. To palliate symptoms of this recurrence, he underwent CyberKnife stereotactic radiosurgery with a clinical and radiographic response of his treated disease. No acute or sub-acute toxicity was seen until the patient's death due to metastatic disease 10 weeks following treatment. The feasibility and short-term safety of this technique are reviewed, with emphasis on the stereotactic planning considerations, such as mediastinal organ movement and radiation tolerance.

  9. Stereotactic radiation therapy for skull base recurrences: Is a salvage approach still possible?

    PubMed Central

    Krengli, Marco; Apicella, Giuseppina; Deantonio, Letizia; Paolini, Marina; Masini, Laura

    2015-01-01

    Aim A literature review was performed to analyse the role of stereotactic radiotherapy given in a single shot or in a fractionated fashion for recurrent skull base tumours in order to ascertain if it can be a real salvage approach. Background The management of recurrent skull base tumours can have a curative or palliative intent and mainly includes surgery and RT. Materials and methods One-thousand-ninety-one articles were found in the search databases and the most relevant of them were analysed and briefly described. Results Data on recurrences of meningioma, pituitary adenoma, craniopharyngioma, chordoma and chondrosarcoma, vestibular schwannoma, glomus jugulare tumours, olfactory neuroblastoma and recurrences from head and neck tumours invading the base of skull are reported highlighting the most relevant results in terms of local control, survival, side effects and complications. Conclusions In conclusion, it emerges that SRS and FSRT are effective and safe radiation modalities of realize real salvage treatment for recurrent skull base tumours. PMID:26696783

  10. Outcomes of postoperative stereotactic radiosurgery to the resection cavity versus stereotactic radiosurgery alone for melanoma brain metastases.

    PubMed

    Minniti, Giuseppe; Paolini, Sergio; D'Andrea, Giancarlo; Lanzetta, Gaetano; Cicone, Francesco; Confaloni, Veronica; Bozzao, Alessandro; Esposito, Vincenzo; Osti, Mattia

    2017-03-04

    To investigate local control and radiation-induced brain necrosis in patients with melanoma brain metastases who received complete resection plus fractionated stereotactic radiosurgery (fSRS, 3 × 9 Gy) or fSRS alone. Factors associated with the clinical outcomes and the development of brain necrosis have been assessed. One hundred and twenty consecutive patients with 137 melanoma brain metastases who received surgery plus fSRS (S + fSRS) or fSRS alone were analyzed. All lesions evaluated in the study were treated with a dose of 27 Gy given in 3 fractions over three consecutive days. Cumulative incidence analysis was used to compare local failure (LF), distant brain failure (DBF), and radiation-induced brain necrosis (RN) between groups from the time of SRS. At a median follow-up of 13 months, median OS times and 1-year survival rates were comparable: S + fSRS, 14 months and 85%; fSRS, 12 months and 85% (p = 0.2). Median DBF did not differ significantly by group, being 14 months for both groups. Nine patients who received S + fSRS and 20 patients treated with fSRS recurred locally (p = 0.03). Six-month and 1-year LF rates were 5 and 12% in S + fSRS group and 17 and 28% in fSRS group (p = 0.02). RN occurred in 21 patients (S + fSRS, n = 14; fSRS, n = 7; p = 0.1). The cumulative 1-year incidence of RN was 13% after S + fSRS and 8% after fSRS (p = 0.15). In conclusion, postoperative SRS (3 × 9 Gy) to the resection cavity is an effective treatment modality for melanoma brain metastases associated with better local control as compared with fSRS alone.

  11. Salvage Reirradiaton With Stereotactic Body Radiotherapy for Locally Recurrent Head-and-Neck Tumors

    SciTech Connect

    Cengiz, Mustafa; Ozyigit, Goekhan; Yazici, Goezde; Dogan, Ali; Yildiz, Ferah; Zorlu, Faruk; Guerkaynak, Murat; Gullu, Ibrahim H.; Hosal, Sefik; Akyol, Fadil

    2011-09-01

    Purpose: In this study, we present our results of reirradiation of locally recurrent head-and-neck cancer with image-guided, fractionated, frameless stereotactic body radiotherapy technique. Methods and Materials: From July 2007 to February 2009, 46 patients were treated using the CyberKnife (Accuray, Sunnyvale, CA) at the Department of Radiation Oncology, Hacettepe University, Ankara, Turkey. All patients had recurrent, unresectable, and previously irradiated head-and-neck cancer. The most prominent site was the nasopharynx (32.6%), and the most common histopathology was epidermoid carcinoma. The planning target volume was defined as the gross tumor volume identified on magnetic resonance imaging and computed tomography. There were 22 female and 24 male patients. Median age was 53 years (range, 19-87 years). The median tumor dose with stereotactic body radiotherapy was 30 Gy (range, 18-35 Gy) in a median of five (range, one to five) fractions. Results: Of 37 patients whose response to therapy was evaluated, 10 patients (27%) had complete tumor regression, 11 (29.8%) had partial response, and 10 (27%) had stable disease. Ultimate local disease control was achieved in 31 patients (83.8%). The overall survival was 11.93 months in median (ranged, 11.4 - 17.4 months), and the median progression free survival was 10.5 months. One-year progression-free survival and overall survival were 41% and 46%, respectively. Grade II or greater long-term complications were observed in 6 (13.3%) patients. On follow-up, 8 (17.3%) patients had carotid blow-out syndrome, and 7 (15.2%) patients died of bleeding from carotid arteries. We discovered that this fatal syndrome occurred only in patients with tumor surrounding carotid arteries and carotid arteries receiving all prescribed dose. Conclusions: Stereotactic body radiotherapy is an appealing treatment option for patients with recurrent head-and-neck cancer previously treated with radiation to high doses. Good local control with

  12. Stereotactic Body Radiotherapy for Metastatic and Recurrent Ewing Sarcoma and Osteosarcoma

    PubMed Central

    Brown, Lindsay C.; Lester, Rachael A.; Grams, Michael P.; Haddock, Michael G.; Olivier, Kenneth R.; Arndt, Carola A. S.; Rose, Peter S.; Laack, Nadia N.

    2014-01-01

    Background. Radiotherapy has been utilized for metastatic and recurrent osteosarcoma and Ewing sarcoma (ES), in order to provide palliation and possibly prolong overall or progression-free survival. Stereotactic body radiotherapy (SBRT) is convenient for patients and offers the possibility of increased efficacy. We report our early institutional experience using SBRT for recurrent and metastatic osteosarcoma and Ewing sarcoma. Methods. We reviewed all cases of osteosarcoma or ES treated with SBRT between 2008 and 2012. Results. We identified 14 patients with a total of 27 lesions from osteosarcoma (n = 19) or ES (n = 8). The median total curative/definitive SBRT dose delivered was 40 Gy in 5 fractions (range, 30–60 Gy in 3–10 fractions). The median total palliative SBRT dose delivered was 40 Gy in 5 fractions (range, 16–50 Gy in 1–10 fractions). Two grade 2 and 1 grade 3 late toxicities occurred, consisting of myonecrosis, avascular necrosis with pathologic fracture, and sacral plexopathy. Toxicity was seen in the settings of concurrent chemotherapy and reirradiation. Conclusions. This descriptive report suggests that SBRT may be a feasible local treatment option for patients with osteosarcoma and ES. However, significant toxicity can result, and thus systematic study is warranted to clarify efficacy and characterize long-term toxicity. PMID:25548538

  13. Evaluation of the peripheral dose in stereotactic radiotherapy and radiosurgery treatments

    SciTech Connect

    Di Betta, Erika; Fariselli, Laura; Bergantin, Achille; Locatelli, Federica; Del Vecchio, Antonella; Broggi, Sara; Fumagalli, Maria Luisa

    2010-07-15

    Purpose: The main purpose of this work was to compare peripheral doses absorbed during stereotactic treatment of a brain lesion delivered using different devices. These data were used to estimate the risk of stochastic effects. Methods: Treatment plans were created for an anthropomorphic phantom and delivered using a LINAC with stereotactic cones and a multileaf collimator, a CyberKnife system (before and after a supplemental shielding was applied), a TomoTherapy system, and a Gamma Knife unit. For each treatment, 5 Gy were prescribed to the target. Measurements were performed with thermoluminescent dosimeters inserted roughly in the position of the thyroid, sternum, upper lung, lower lung, and gonads. Results: Mean doses ranged from of 4.1 (Gamma Knife) to 62.8 mGy (LINAC with cones) in the thyroid, from 2.3 (TomoTherapy) to 30 mGy (preshielding CyberKnife) in the sternum, from 1.7 (TomoTherapy) to 20 mGy (preshielding CyberKnife) in the upper part of the lungs, from 0.98 (Gamma Knife) to 15 mGy (preshielding CyberKnife) in the lower part of the lungs, and between 0.3 (Gamma Knife) and 10 mGy (preshielding CyberKnife) in the gonads. Conclusions: The peripheral dose absorbed in the sites of interest with a 5 Gy fraction is low. Although the risk of adverse side effects calculated for 20 Gy delivered in 5 Gy fractions is negligible, in the interest of optimum patient radioprotection, further studies are needed to determine the weight of each contributor to the peripheral dose.

  14. Accumulated Dose in Liver Stereotactic Body Radiotherapy: Positioning, Breathing, and Deformation Effects

    SciTech Connect

    Velec, Michael; Moseley, Joanne L.; Craig, Tim; Dawson, Laura A.; Brock, Kristy K.

    2012-07-15

    Purpose: To investigate the accumulated dose deviations to tumors and normal tissues in liver stereotactic body radiotherapy (SBRT) and investigate their geometric causes. Methods and Materials: Thirty previously treated liver cancer patients were retrospectively evaluated. Stereotactic body radiotherapy was planned on the static exhale CT for 27-60 Gy in 6 fractions, and patients were treated in free-breathing with daily cone-beam CT guidance. Biomechanical model-based deformable image registration accumulated dose over both the planning four-dimensional (4D) CT (predicted breathing dose) and also over each fraction's respiratory-correlated cone-beam CT (accumulated treatment dose). The contribution of different geometric errors to changes between the accumulated and predicted breathing dose were quantified. Results: Twenty-one patients (70%) had accumulated dose deviations relative to the planned static prescription dose >5%, ranging from -15% to 5% in tumors and -42% to 8% in normal tissues. Sixteen patients (53%) still had deviations relative to the 4D CT-predicted dose, which were similar in magnitude. Thirty-two tissues in these 16 patients had deviations >5% relative to the 4D CT-predicted dose, and residual setup errors (n = 17) were most often the largest cause of the deviations, followed by deformations (n = 8) and breathing variations (n = 7). Conclusion: The majority of patients had accumulated dose deviations >5% relative to the static plan. Significant deviations relative to the predicted breathing dose still occurred in more than half the patients, commonly owing to residual setup errors. Accumulated SBRT dose may be warranted to pursue further dose escalation, adaptive SBRT, and aid in correlation with clinical outcomes.

  15. Outcomes and toxicities of stereotactic body radiation therapy for non-spine bone oligometastases

    PubMed Central

    Owen, Dawn; Laack, Nadia N.; Mayo, Charles S.; Garces, Yolanda I.; Park, Sean S.; Bauer, Heather J.; Nelson, Kathryn; Miller, Robert W.; Brown, Paul D.; Olivier, Kenneth R.

    2015-01-01

    Purpose Stereotactic body radiation therapy (SBRT) is being applied more widely for oligometastatic disease. This technique is now being used for non-spine bony metastases in addition to liver, spine, and lung. However, there are few studies examining the toxicity and outcomes of SBRT for non-spine bone metastases. Methods and Materials Between 2008 and 2012, 74 subjects with oligometastatic non-spine bony metastases of varying histologies were treated at the Mayo Clinic with SBRT. A total of 85 non-spine bony sites were treated. Median local control, overall survival, and progression-free survival were described. Acute toxicity (defined as toxicity <90 days) and late toxicity (defined as toxicity ≥90 days) were reported and graded as per standardized Common Toxicity Criteria for Adverse Events 4.0 criteria. Results The median age of patients treated was 60 years. The most common histology was prostate cancer (31%) and most patients had fewer than 3 sites of disease at the time of simulation (64%). Most of the non-spine bony sites lay within the pelvis (65%). Dose and fractionation varied but the most common prescription was 24 Gy/1 fraction. Local recurrence occurred in 7 patients with a median time to failure of 2.8 months. Local control was 91.8% at 1 year. With a median follow-up of 7.6 months, median SBRT specific overall survival and progression-free survival were 9.3 months and 9.7 months, respectively. Eighteen patients developed acute toxicity (mostly grade 1 and 2 fatigue and acute pain flare); 9 patients developed grade 1–2 late toxicities. Two patients developed pathologic fractures but both were asymptomatic. There were no late grade 3 or 4 toxicities. Conclusions Stereotactic body radiation therapy is a feasible and tolerable treatment for non-spine bony metastases. Longer follow-up will be needed to accurately determine late effects. PMID:24890360

  16. Stereotactic Body Radiation Therapy for Re-irradiation of Persistent or Recurrent Non-Small Cell Lung Cancer

    SciTech Connect

    Trovo, Marco; Minatel, Emilio; Durofil, Elena; Polesel, Jerry; Avanzo, Michele; Baresic, Tania; Bearz, Alessandra; Del Conte, Alessandro; Franchin, Giovanni; Gobitti, Carlo; Rumeileh, Imad Abu; Trovo, Mauro G.

    2014-04-01

    Purpose: To retrospectively assess toxicity and outcome of re-irradiation with stereotactic body radiation therapy (SBRT) in patients with recurrent or persistent non-small cell lung cancer (NSCLC), who were previously treated with radical radiation therapy (50-60 Gy). The secondary endpoint was to investigate whether there are dosimetric parameter predictors of severe radiation toxicity. Methods and Materials: The analysis was conducted in 17 patients with “in-field” recurrent/persistent centrally located NSCLC, who underwent re-irradiation with SBRT. SBRT consisted of 30 Gy in 5 to 6 fractions; these prescriptions would be equivalent for the tumor to 37.5 to 40 Gy, bringing the total 2-Gy-per-fraction cumulative dose to 87 to 100 Gy, considering the primary radiation therapy treatment. Actuarial analyses and survival were calculated by the Kaplan-Meier method, and P values were estimated by the log-rank test, starting from the date of completion of SBRT. Dosimetric parameters from the subgroups with and without grade ≥3 pulmonary toxicity were compared using a 2-tailed Student t test. Results: The median follow-up was 18 months (range, 4-57 months). Only 2 patients had local failure, corresponding to a local control rate of 86% at 1 year. The Kaplan-Meier estimates of overall survival (OS) rates at 1 and 2 years were 59% and 29%, respectively; the median OS was 19 months. Four patients (23%) experienced grade 3 radiation pneumonitis, and 1 patient developed fatal pneumonitis. One patient died of fatal hemoptysis 2 months after the completion of SBRT. Unexpectedly, heart maximum dose, D5 (minimum dose to at least 5% of the heart volume), and D10 were correlated with risk of radiation pneumonitis (P<.05). Conclusions: Re-irradiation with SBRT for recurrent/persistent centrally located NSCLC achieves excellent results in terms of local control. However, the high rate of severe toxicity reported in our study is of concern.

  17. Dose-Volume Parameters Predict for the Development of Chest Wall Pain After Stereotactic Body Radiation for Lung Cancer

    SciTech Connect

    Mutter, Robert W.; Liu Fan; Abreu, Andres; Yorke, Ellen; Jackson, Andrew; Rosenzweig, Kenneth E.

    2012-04-01

    Purpose: Chest wall (CW) pain has recently been recognized as an important adverse effect of stereotactic body radiation therapy (SBRT) for non-small-cell lung cancer (NSCLC). We developed a dose-volume model to predict the development of this toxicity. Methods and Materials: A total of 126 patients with primary, clinically node-negative NSCLC received three to five fractions of SBRT to doses of 40-60 Gy and were prospectively followed. The dose-absolute volume histograms of two different definitions of the CW as an organ at risk (CW3cm and CW2cm) were examined for all 126 patients. Results: With a median follow-up of 16 months, the 2-year estimated actuarial incidence of Grade {>=} 2 CW pain was 39%. The median time to onset of Grade {>=} 2 CW pain (National Cancer Institute Common Terminology Criteria for Adverse Events, Version 3.0) was 9 months. There was no predictive advantage for biologically corrected dose over physical dose. Neither fraction number (p = 0.07) nor prescription dose (p = 0.07) were significantly correlated with the development of Grade {>=} 2 CW pain. Cox Proportional Hazards analysis identified significant correlation with a broad range of dose-volume combinations, with the CW volume receiving 30 Gy (V30) as one of the strongest predictors (p < 0.001). CW2cm consistently enabled better prediction of CW toxicity. When a physical dose of 30 Gy was received by more than 70 cm{sup 3} of CW2cm, there was a significant correlation with Grade {>=} 2 CW pain (p = 0.004). Conclusions: CW toxicity after SBRT is common and long-term follow-up is needed to identify affected patients. A volume of CW {>=} 70 cm{sup 3} receiving 30 Gy is significantly correlated with Grade {>=} 2 CW pain. We are currently applying this constraint at our institution for patients receiving thoracic SBRT. An actuarial atlas of our data is provided as an electronic supplement to facilitate data-sharing and meta-analysis relating to CW pain.

  18. Fractional randomness

    NASA Astrophysics Data System (ADS)

    Tapiero, Charles S.; Vallois, Pierre

    2016-11-01

    The premise of this paper is that a fractional probability distribution is based on fractional operators and the fractional (Hurst) index used that alters the classical setting of random variables. For example, a random variable defined by its density function might not have a fractional density function defined in its conventional sense. Practically, it implies that a distribution's granularity defined by a fractional kernel may have properties that differ due to the fractional index used and the fractional calculus applied to define it. The purpose of this paper is to consider an application of fractional calculus to define the fractional density function of a random variable. In addition, we provide and prove a number of results, defining the functional forms of these distributions as well as their existence. In particular, we define fractional probability distributions for increasing and decreasing functions that are right continuous. Examples are used to motivate the usefulness of a statistical approach to fractional calculus and its application to economic and financial problems. In conclusion, this paper is a preliminary attempt to construct statistical fractional models. Due to the breadth and the extent of such problems, this paper may be considered as an initial attempt to do so.

  19. Dosimetric effect of intrafraction tumor motion in phase gated lung stereotactic body radiotherapy

    SciTech Connect

    Zhao Bo; Yang Yong; Li Tianfang; Li Xiang; Heron, Dwight E.; Huq, M. Saiful

    2012-11-15

    Purpose: A major concern for lung intensity modulated radiation therapy delivery is the deviation of actually delivered dose distribution from the planned one due to simultaneous movements of multileaf collimator (MLC) leaves and tumor. For gated lung stereotactic body radiotherapy treatment (SBRT), the situation becomes even more complicated because of SBRT's characteristics such as fewer fractions, smaller target volume, higher dose rate, and extended fractional treatment time. The purpose of this work is to investigate the dosimetric effect of intrafraction tumor motion during gated lung SBRT delivery by reconstructing the delivered dose distribution with real-time tumor motion considered. Methods: The tumor motion data were retrieved from six lung patients. Each of them received three fractions of stereotactic radiotherapy treatments with Cyberknife Synchrony (Accuray, Sunnyvale, CA). Phase gating through an external surrogate was simulated with a gating window of 5 mm. The resulting residual tumor motion curves during gating (beam-on) were retrieved. Planning target volume (PTV) was defined as physician-contoured clinical target volume (CTV) surrounded by an isotropic 5 mm margin. Each patient was prescribed with 60 Gy/3 fractions. The authors developed an algorithm to reconstruct the delivered dose with tumor motion. The DMLC segments, mainly leaf position and segment weighting factor, were recalculated according to the probability density function of tumor motion curve. The new DMLC sequence file was imported back to treatment planning system to reconstruct the dose distribution. Results: Half of the patients in the study group experienced PTV D95% deviation up to 26% for fractional dose and 14% for total dose. CTV mean dose dropped by 1% with tumor motion. Although CTV is almost covered by prescribed dose with 5 mm margin, qualitative comparison on the dose distributions reveals that CTV is on the verge of underdose. The discrepancy happens due to tumor

  20. Recursive Partitioning Analysis Index Is Predictive for Overall Survival in Patients Undergoing Spine Stereotactic Body Radiation Therapy for Spinal Metastases

    SciTech Connect

    Chao, Samuel T.; Koyfman, Shlomo A.; Woody, Neil; Angelov, Lilyana; Soeder, Sherry L.; Reddy, Chandana A.; Rybicki, Lisa A.; Djemil, Toufik; Suh, John H.

    2012-04-01

    Purpose: To generate a prognostic index using recursive partitioning analysis (RPA) for patients undergoing spine stereotactic body radiation therapy (sSBRT) for spinal metastases (sMet). Methods and Materials: From an institutional review board-approved database, 174 patients were treated for sMet with sSBRT between February 2006 and August 2009. Median dose was 14 Gy (range, 8-24 Gy), typically in a single fraction (range, 1-5). Kaplan-Meier analysis was performed to detect any correlation between survival and histology. Histologies were divided into favorable (breast and prostate), radioresistant (renal cell, melanoma and sarcoma), and other (all other histologies). RPA was performed to identify any association of the following variables with overall survival (OS) following sSBRT: histology, gender, age, Karnofsky performance status (KPS), control of primary, extraosseous metastases, time from primary diagnosis (TPD), dose of sSBRT ({<=}14 Gy vs. >14 Gy), extent of spine disease (epidural only, bone and epidural, bone only), upfront or salvage treatment, presence of paraspinal extension, and previous surgery. Results: Median follow-up was 8.9 months. Median OS time from sSBRT was 10.7 months. Median OS intervals for favorable histologies were 14 months, 11.2 months for radioresistant histologies, and 7.3 months for other histologies (p = 0.02). RPA analysis resulted in three classes (p < 0.0001). Class 1 was defined as TPD of >30 months and KPS of >70; Class 2 was TPD of >30 months and KPS of {<=}70 or a TPD of {<=}30 months and age <70 years old; Class 3 was TPD of {<=}30 months and age {>=}70 years old. Median OS was 21.1 months for Class 1 (n = 59), 8.7 months for Class 2 (n = 104), and 2.4 months for Class 3 (n = 11). Conclusion: sSBRT patients treated for sMet have a wide variability in OS. We developed an RPA classification system that is predictive of OS. While many patients are treated for palliation of pain or to avoid symptomatic progression, this

  1. Adaptive Stereotactic Body Radiation Therapy Planning for Lung Cancer

    SciTech Connect

    Qin, Yujiao; Zhang, Fan; Yoo, David S.; Kelsey, Chris R.; Yin, Fang-Fang; Cai, Jing

    2013-09-01

    Purpose: To investigate the dosimetric effects of adaptive planning on lung stereotactic body radiation therapy (SBRT). Methods and Materials: Forty of 66 consecutive lung SBRT patients were selected for a retrospective adaptive planning study. CBCT images acquired at each fraction were used for treatment planning. Adaptive plans were created using the same planning parameters as the original CT-based plan, with the goal to achieve comparable comformality index (CI). For each patient, 2 cumulative plans, nonadaptive plan (P{sub NON}) and adaptive plan (P{sub ADP}), were generated and compared for the following organs-at-risks (OARs): cord, esophagus, chest wall, and the lungs. Dosimetric comparison was performed between P{sub NON} and P{sub ADP} for all 40 patients. Correlations were evaluated between changes in dosimetric metrics induced by adaptive planning and potential impacting factors, including tumor-to-OAR distances (d{sub T-OAR}), initial internal target volume (ITV{sub 1}), ITV change (ΔITV), and effective ITV diameter change (Δd{sub ITV}). Results: 34 (85%) patients showed ITV decrease and 6 (15%) patients showed ITV increase throughout the course of lung SBRT. Percentage ITV change ranged from −59.6% to 13.0%, with a mean (±SD) of −21.0% (±21.4%). On average of all patients, P{sub ADP} resulted in significantly (P=0 to .045) lower values for all dosimetric metrics. Δd{sub ITV}/d{sub T-OAR} was found to correlate with changes in dose to 5 cc (ΔD5cc) of esophagus (r=0.61) and dose to 30 cc (ΔD30cc) of chest wall (r=0.81). Stronger correlations between Δd{sub ITV}/d{sub T-OAR} and ΔD30cc of chest wall were discovered for peripheral (r=0.81) and central (r=0.84) tumors, respectively. Conclusions: Dosimetric effects of adaptive lung SBRT planning depend upon target volume changes and tumor-to-OAR distances. Adaptive lung SBRT can potentially reduce dose to adjacent OARs if patients present large tumor volume shrinkage during the treatment.

  2. Pulmonary Function Testing After Stereotactic Body Radiotherapy to the Lung

    SciTech Connect

    Bishawi, Muath; Kim, Bong; Moore, William H.; Bilfinger, Thomas V.

    2012-01-01

    Purpose: Surgical resection remains the standard of care for operable early-stage non-small-cell lung cancer (NSCLC). However, some patients are not fit for surgery because of comorbidites such as chronic obstructive pulmonary disease (COPD) and other medical conditions. We aimed to evaluate pulmonary function and tumor volume before and after stereotactic body radiotherapy (SBRT) for patients with and without COPD in early-stage lung cancer. Methods and Materials: A review of prospectively collected data of Stage I and II lung cancers, all treated with SBRT, was performed. The total SBRT treatment was 60 Gy administered in three 20 Gy fractions. The patients were analyzed based on their COPD status, using their pretreatment pulmonary function test cutoffs as established by the American Thoracic Society guidelines (forced expiratory volume [FEV]% {<=}50% predicted, FEV%/forced vital capacity [FVC]% {<=}70%). Changes in tumor volume were also assessed by computed tomography. Results: Of a total of 30 patients with Stage I and II lung cancer, there were 7 patients in the COPD group (4 men, 3 women), and 23 in t he No-COPD group (9 men, 14 women). At a mean follow-up time of 4 months, for the COPD and No-COPD patients, pretreatment and posttreatment FEV% was similar: 39 {+-} 5 vs. 40 {+-} 9 (p = 0.4) and 77 {+-} 0.5 vs. 73 {+-} 24 (p = 0.9), respectively. The diffusing capacity of the lungs for carbon monoxide (DL{sub CO}) did significantly increase for the No-COPD group after SBRT treatment: 60 {+-} 24 vs. 69 {+-} 22 (p = 0.022); however, DL{sub CO} was unchanged for the COPD group: 49 {+-} 13 vs. 50 {+-} 14 (p = 0.8). Although pretreatment tumor volume was comparable for both groups, tumor volume significantly shrank in the No-COPD group from 19 {+-} 24 to 9 {+-} 16 (p < 0.001), and there was a trend in the COPD patients from 12 {+-} 9 to 6 {+-} 5 (p = 0.06). Conclusion: SBRT did not seem to have an effect on FEV{sub 1} and FVC, but it shrank tumor volume and

  3. Retreatment for prostate cancer with stereotactic body radiation therapy (SBRT): Feasible or foolhardy?

    PubMed

    Arcangeli, Stefano; Agolli, Linda; Donato, Vittorio

    2015-01-01

    The most popular therapeutic option in the management of radio-recurrent prostatic carcinoma is represented by the androgen deprivation therapy, that however should be considered only palliative and hampered by potential adverse effects of testosterone suppression. Local therapies such as surgery, cryoablation or brachytherapy might be curative choices for patients in good conditions and with a long-life expectancy, but at cost of significant risk of failure and severe toxicity. The administration of stereotactic body radiation therapy (SBRT) in this setting have come about because of tremendous technologic advances in image guidance and treatment delivery techniques that enable the delivery of large doses to tumor with reduced margins and high gradients outside the target, thereby reducing the volume of rectum which already received significant doses from primary radiotherapy. So far, very modest data are available to support its employment. Rationale, clinical experience, and challenges are herein reviewed and discussed.

  4. A comparison of robotic arm versus gantry linear accelerator stereotactic body radiation therapy for prostate cancer.

    PubMed

    Avkshtol, Vladimir; Dong, Yanqun; Hayes, Shelly B; Hallman, Mark A; Price, Robert A; Sobczak, Mark L; Horwitz, Eric M; Zaorsky, Nicholas G

    2016-01-01

    Prostate cancer is the most prevalent cancer diagnosed in men in the United States besides skin cancer. Stereotactic body radiation therapy (SBRT; 6-15 Gy per fraction, up to 45 minutes per fraction, delivered in five fractions or less, over the course of approximately 2 weeks) is emerging as a popular treatment option for prostate cancer. The American Society for Radiation Oncology now recognizes SBRT for select low- and intermediate-risk prostate cancer patients. SBRT grew from the notion that high doses of radiation typical of brachytherapy could be delivered noninvasively using modern external-beam radiation therapy planning and delivery methods. SBRT is most commonly delivered using either a traditional gantry-mounted linear accelerator or a robotic arm-mounted linear accelerator. In this systematic review article, we compare and contrast the current clinical evidence supporting a gantry vs robotic arm SBRT for prostate cancer. The data for SBRT show encouraging and comparable results in terms of freedom from biochemical failure (>90% for low and intermediate risk at 5-7 years) and acute and late toxicity (<6% grade 3-4 late toxicities). Other outcomes (eg, overall and cancer-specific mortality) cannot be compared, given the indolent course of low-risk prostate cancer. At this time, neither SBRT device is recommended over the other for all patients; however, gantry-based SBRT machines have the abilities of treating larger volumes with conventional fractionation, shorter treatment time per fraction (~15 minutes for gantry vs ~45 minutes for robotic arm), and the ability to achieve better plans among obese patients (since they are able to use energies >6 MV). Finally, SBRT (particularly on a gantry) may also be more cost-effective than conventionally fractionated external-beam radiation therapy. Randomized controlled trials of SBRT using both technologies are underway.

  5. A comparison of robotic arm versus gantry linear accelerator stereotactic body radiation therapy for prostate cancer

    PubMed Central

    Avkshtol, Vladimir; Dong, Yanqun; Hayes, Shelly B; Hallman, Mark A; Price, Robert A; Sobczak, Mark L; Horwitz, Eric M; Zaorsky, Nicholas G

    2016-01-01

    Prostate cancer is the most prevalent cancer diagnosed in men in the United States besides skin cancer. Stereotactic body radiation therapy (SBRT; 6–15 Gy per fraction, up to 45 minutes per fraction, delivered in five fractions or less, over the course of approximately 2 weeks) is emerging as a popular treatment option for prostate cancer. The American Society for Radiation Oncology now recognizes SBRT for select low- and intermediate-risk prostate cancer patients. SBRT grew from the notion that high doses of radiation typical of brachytherapy could be delivered noninvasively using modern external-beam radiation therapy planning and delivery methods. SBRT is most commonly delivered using either a traditional gantry-mounted linear accelerator or a robotic arm-mounted linear accelerator. In this systematic review article, we compare and contrast the current clinical evidence supporting a gantry vs robotic arm SBRT for prostate cancer. The data for SBRT show encouraging and comparable results in terms of freedom from biochemical failure (>90% for low and intermediate risk at 5–7 years) and acute and late toxicity (<6% grade 3–4 late toxicities). Other outcomes (eg, overall and cancer-specific mortality) cannot be compared, given the indolent course of low-risk prostate cancer. At this time, neither SBRT device is recommended over the other for all patients; however, gantry-based SBRT machines have the abilities of treating larger volumes with conventional fractionation, shorter treatment time per fraction (~15 minutes for gantry vs ~45 minutes for robotic arm), and the ability to achieve better plans among obese patients (since they are able to use energies >6 MV). Finally, SBRT (particularly on a gantry) may also be more cost-effective than conventionally fractionated external-beam radiation therapy. Randomized controlled trials of SBRT using both technologies are underway. PMID:27574585

  6. Once-Weekly, High-Dose Stereotactic Body Radiotherapy for Lung Cancer: 6-Year Analysis of 60 Early-Stage, 42 Locally Advanced, and 7 Metastatic Lung Cancers

    SciTech Connect

    Salazar, Omar M. Sandhu, Taljit S.; Lattin, Paul B.; Chang, Jung H.; Lee, Choon K.; Groshko, Gayle A.; Lattin, Cheryl J.

    2008-11-01

    Purpose: To explore once-weekly stereotactic body radiotherapy (SBRT) in nonoperable patients with localized, locally advanced, or metastatic lung cancer. Methods and Materials: A total of 102 primary (89 untreated plus 13 recurrent) and 7 metastatic tumors were studied. The median follow-up was 38 months, the average patient age was 75 years. Of the 109 tumors studied, 60 were Stage I (45 IA and 15 IB), 9 were Stage II, 30 were Stage III, 3 were Stage IV, and 7 were metastases. SBRT only was given in 73% (40 Gy in four fractions to the planning target volume to a total dose of 53 Gy to the isocenter for a biologically effective dose of 120 Gy{sub 10}). SBRT was given as a boost in 27% (22.5 Gy in three fractions once weekly for a dose of 32 Gy at the isocenter) after 45 Gy in 25 fractions to the primary plus the mediastinum. The total biologically effective dose was 120 Gy{sub 10}. Respiration gating was used in 46%. Results: The overall response rate was 75%; 33% had a complete response. The overall response rate was 89% for Stage IA patients (40% had a complete response). The local control rate was 82%; it was 100% and 93% for Stage IA and IB patients, respectively. The failure rate was 37%, with 17% within the planning target volume. No Grade 3-4 acute toxicities developed in any patient; 12% and 7% of patients developed Grade 1 and 2 toxicities, respectively. Late toxicity, all Grade 2, developed in 3% of patients. The 5-year cause-specific survival rate for Stage I was 70% and was 74% and 64% for Stage IA and IB patients, respectively. The 3-year Stage III cause-specific survival rate was 30%. The patients with metastatic lung cancer had a 57% response rate, a 27% complete response rate, an 86% local control rate, a median survival time of 19 months, and 23% 3-year survival rate. Conclusions: SBRT is noninvasive, convenient, fast, and economically attractive; it achieves results similar to surgery for early or metastatic lung cancer patients who are older

  7. Characterization of dose in stereotactic body radiation therapy of lung lesions via Monte Carlo calculation

    NASA Astrophysics Data System (ADS)

    Rassiah, Premavathy

    Stereotactic Body Radiation Therapy is a new form of treatment where hypofractionated (i.e., large dose fractions), conformal doses are delivered to small extracranial target volumes. This technique has proven to be especially effective for treating lung lesions. The inability of most commercially available algorithms/treatment planning systems to accurately account for electron transport in regions of heterogeneous electron density and tissue interfaces make prediction of accurate doses especially challenging for such regions. Monte Carlo which a model based calculation algorithm has proven to be extremely accurate for dose calculation in both homogeneous and inhomogeneous environment. This study attempts to accurately characterize the doses received by static targets located in the lung, as well as critical structures (contra and ipsi -lateral lung, major airways, esophagus and spinal cord) for the serial tomotherapeutic intensity-modulated delivery method used for stereotactic body radiation therapy at the Cancer Therapy and Research Center. PEREGRINERTM (v 1.6. NOMOS) Monte Carlo, doses were compared to the Finite Sized Pencil Beam/Effective Path Length predicted values from the CORVUS 5.0 planning system. The Monte Carlo based treatment planning system was first validated in both homogenous and inhomogeneous environments. 77 stereotactic body radiation therapy lung patients previously treated with doses calculated using the Finite Sized Pencil Beam/Effective Path Length, algorithm were then retrieved and recalculated with Monte Carlo. All 77 patients plans were also recalculated without inhomogeneity correction in an attempt to counteract the known overestimation of dose at the periphery of the target by EPL with increased attenuation. The critical structures were delineated in order to standardize the contouring. Both the ipsi-lateral and contra-lateral lungs were contoured. The major airways were contoured from the apex of the lungs (trachea) to 4 cm below

  8. Implementation of a volumetric modulated arc therapy treatment planning solution for kidney and adrenal stereotactic body radiation therapy.

    PubMed

    Sonier, Marcus; Chu, William; Lalani, Nafisha; Erler, Darby; Cheung, Patrick; Korol, Renee

    2016-01-01

    To develop a volumetric modulated arc therapy (VMAT) treatment planning solution in the treatment of primary renal cell carcinoma and oligometastatic adrenal lesions with stereotactic body radiation therapy. Single-arc VMAT plans (n = 5) were compared with clinically delivered step-and-shoot intensity-modulated radiotherapy (IMRT) with planning target volume coverage normalized between techniques. Target volume conformity, organ-at-risk (OAR) dose, treatment time, and monitor units were compared. A VMAT planning solution, created from a combination of arc settings and optimization constraints, auto-generated treatment plans in a single optimization. The treatment planning solution was evaluated on 15 consecutive patients receiving kidney and adrenal stereotactic body radiation therapy. Treatment time was reduced from 13.0 ± 2.6 to 4.0 ± 0.9 minutes for IMRT and VMAT, respectively. The VMAT planning solution generated treatment plans with increased target homogeneity, improved 95% conformity index, and a reduced maximum point dose to nearby OARs but with increased intermediate dose to distant OARs. The conformity of the 95% isodose improved from 1.32 ± 0.39 to 1.12 ± 0.05 for IMRT and VMAT treatment plans, respectively. Evaluation of the planning solution showed clinically acceptable dose distributions for 13 of 15 cases with tight conformity of the prescription isodose to the planning target volume of 1.07 ± 0.04, delivering minimal dose to OARs. The introduction of a stereotactic body radiation therapy VMAT treatment planning solution improves the efficiency of planning and delivery time, producing treatment plans of comparable or superior quality to IMRT in the case of primary renal cell carcinoma and oligometastatic adrenal lesions.

  9. [Nationwide implementation of stereotactic radiotherapy: the challenges of initial training and continuing professional education].

    PubMed

    Bibault, J-E; Denis, F; Marchesi, V; Lisbona, A; Noël, G; Mahé, M A

    2014-10-01

    Stereotactic body radiation therapy is a rapidly growing advanced treatment technique that delivers high radiation dose with great precision. The implementation of stereotactic body radiation therapy should be associated with a specific initial training and continuing professional education for radiation oncologists and medical physicists. The creation of a French stereotactic body radiation therapy group gathering radiation oncologists (SFRO and AFCOR) and medical physicists (SFPM) is mandatory in order to create dedicated national guidelines, prospective databases and to promote clinical trials in this field.

  10. Resection Followed by Stereotactic Radiosurgery to Resection Cavity for Intracranial Metastases

    SciTech Connect

    Do, Ly Pezner, Richard; Radany, Eric; Liu An; Staud, Cecil; Badie, Benham

    2009-02-01

    Purpose: In patients who undergo resection of central nervous system metastases, whole brain radiotherapy (WBRT) is added to reduce the rates of recurrence and neurologic death. However, the risk of late neurotoxicity has led many patients to decline WBRT. We offered adjuvant stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) as an alternative to select patients with resected brain metastases. Methods and Materials: We performed a retrospective review of patients who underwent brain metastasis resection followed by SRS/SRT. WBRT was administered only as salvage treatment. Patients had one to four brain metastases. The dose was 15-18 Gy for SRS and 22-27.5 Gy in four to six fractions for SRT. Target margins were typically expanded by 1 mm for rigid immobilization and 3 mm for mask immobilization. SRS/SRT involved the use of linear accelerator radiosurgery using the IMRT 21EX or Helical Tomotherapy unit. Results: Between December 1999 and January 2007, 30 patients diagnosed with intracranial metastases were treated with resection followed by SRS or SRT to the resection cavity. Of the 30 patients, 4 (13.3%) developed recurrence in the resection cavity, and 19 (63%) developed recurrences in new intracranial sites. The actuarial 12-month survival rate was 82% for local recurrence-free survival, 31% for freedom from new brain metastases, 67% for neurologic deficit-free survival, and 51% for overall survival. Salvage WBRT was performed in 14 (47%) of the 30 patients. Conclusion: Our results suggest that for patients with newly diagnosed brain metastases treated with surgical resection, postoperative SRS/SRT to the resection cavity is a feasible option. WBRT can be reserved as salvage treatment with acceptable neurologic deficit-free survival.

  11. Three-dimensional interactive and stereotactic human brain atlas of white matter tracts.

    PubMed

    Nowinski, Wieslaw L; Chua, Beng Choon; Yang, Guo Liang; Qian, Guo Yu

    2012-01-01

    We present a human brain atlas of white matter (WM) tracts containing 40 major tracts, which is three-dimensional (3D), segmented, labeled, interactive, stereotactic and correlated to structure and vasculature. We consider: (1) WM accuracy by correlating WM tracts to underlying neuroanatomy and quantifying them; (2) balance between realism and completeness by processing a sequence of track volumes generated for various parameters with the increasing track number to enable a tract "shape convergence". MPRAGE and DTI in 64 directions of the same subject were acquired on 3 Tesla. The method has three steps: DTI-MPRAGE registration, 3D tract generation from DTI, to WM reconstruction from MPRAGE to parcellation into 17 components. 82 track volumes were generated for a wide spectrum of parameter values: Fractional Anisotropy threshold in [0.0125, 0.55] and trajectory angle lower than 45°, 60°, 65°, 70°, 75°, 80°, 85°, 90°. For each tract, a sequence of track volumes was processed to create/edit contours delineating this tract to achieve its shape convergence. The parcellated tracts were grouped into commissures, associations, projections and posterior fossa tracts, and labeled following Terminologia Anatomica. To facilitate that, a dedicated tract editor is developed which processes multiple track volumes, handles tracts in three representations (tracks, contours, envelopes); provides editing/visualization simultaneously on axial, coronal, sagittal planes; enables tract labeling and coloring; and provides numerous tools (track counting, smoothing and length thresholding; representation conversion and saving; structural atlas support). A stereotactic tract atlas along with parcellated WM was developed to explore in real-time any individual tract or their groups along with surrounding neuroanatomy.

  12. Decision theoretic steering and genetic algorithm optimization: application to stereotactic radiosurgery treatment planning.

    PubMed

    Yu, Y; Schell, M C; Zhang, J B

    1997-11-01

    Treatment planning for stereotactic radiosurgery and fractionated radiotherapy is currently a labor intensive, operator-dependent process. Many degrees of freedom exist to make rigorous optimization intractable except by computationally intelligent techniques. The quality of a given plan is determined by an aggregate of clinical objectives, most of which are subject to competing tradeoffs. In this work, we present an autonomous scheme that couples decision theoretic guidance with a genetic algorithm for optimization. Ordinal ranking among a population of viable treatment plans is based on a generalized distance metric, which promotes a decreasing hyperfrontier of the efficient solution set. The solution set is driven toward efficiency by the genetic algorithm, which uses the tournament selection mechanism based on the ordinal ranking. Goals and satisficing conditions can be defined to signal the ultimate and the minimum achievement levels in a given objective. A conventionally challenging case in radiosurgery was used to demonstrate the practical utility and the problem-solving power of the decision theoretic genetic algorithm. Treatment plans with one isocenter and four isocenters were derived under the autonomous scheme and compared to the actual treatment plan manually optimized by the expert planner. Quality assessment based on dose-volume histograms and normal tissue complication probabilities suggested that computational optimization could be driven to offer varying degrees of dosimetric improvement over a human-guided optimization effort. Furthermore, it was possible to achieve a high degree of isodose conformity to the target volume in computational optimization by increasing the degree of freedom in the treatment parameters. The time taken to derive an efficient planning solution was comparable and usually shorter than in the manual planning process, and can be scaled down almost linearly with the number of processors. Overall, the autonomous genetic

  13. Clinical Outcome of Hypofractionated Stereotactic Radiotherapy for Abdominal Lymph Node Metastases

    SciTech Connect

    Bignardi, Mario; Navarria, Piera; Mancosu, Pietro; Cozzi, Luca; Fogliata, Antonella; Tozzi, Angelo; Castiglioni, Simona; Carnaghi, Carlo; Tronconi, Maria Chiara; Santoro, Armando; Scorsetti, Marta

    2011-11-01

    Purpose: We report the medium-term clinical outcome of hypofractionated stereotactic body radiotherapy (SBRT) in a series of patients with either a solitary metastasis or oligometastases from different tumors to abdominal lymph nodes. Methods and Materials: Between January 2006 and June 2009, 19 patients with unresectable nodal metastases in the abdominal retroperitoneal region were treated with SBRT. Of the patients, 11 had a solitary nodal metastasis and 8 had a dominant nodal lesion as part of oligometastatic disease, defined as up to five metastases. The dose prescription was 45 Gy to the clinical target volume in six fractions. The prescription had to be downscaled by 10% to 20% in 6 of 19 cases to keep within dose/volume constraints. The first 11 patients were treated with three-dimensional conformal techniques and the last 8 by volumetric intensity-modulated arc therapy. Median follow-up was 1 year. Results: Of 19 patients, 2 had a local progression at the site of SBRT; both also showed concomitant tumor growth at distant sites. The actuarial rate of freedom from local progression was 77.8% {+-} 13.9% at both 12 and 24 months. Eleven patients showed progressive local and/or distant disease at follow-up. The 12- and 24-month progression-free survival rates were 29.5% {+-} 13.4% and 19.7% {+-} 12.0%, respectively. The number of metastases (solitary vs. nonsolitary oligometastases) emerged as the only significant variable affecting progression-free survival (p < 0.0004). Both acute and chronic toxicities were minimal. Conclusions: Stereotactic body radiotherapy for metastases to abdominal lymph nodes was shown to be feasible with good clinical results in terms of medium-term local control and toxicity rates. Even if most patients eventually show progressive disease at other sites, local control achieved by SBRT may be potentially significant for preserving quality of life and delaying further chemotherapy.

  14. Minimally Invasive Stereotactical Radio-ablation of Adrenal Metastases as an Alternative to Surgery

    PubMed Central

    Franzese, Ciro; Franceschini, Davide; Cozzi, Luca; D’Agostino, Giuseppe; Comito, Tiziana; De Rose, Fiorenza; Navarria, Pierina; Mancosu, Pietro; Tomatis, Stefano; Fogliata, Antonella; Scorsetti, Marta

    2017-01-01

    Purpose The purpose of this study was to study the clinical outcome for patients with metastases of the adrenal gland treated with stereotactic body radiation therapy. Materials and Methods Forty-six patients were studied retrospectively. The dose prescription was 40 Gy in four fractions. Dosimetric analysis was performed using the dose volume histograms while clinical outcome was assessed using actuarial analysis with determination of the overall survival (OS) and local control (LC) rates. Results The planning objectives were met for all patients. With a median follow-up period of 7.6 months, at the last follow-up 42 patients (91.3%) were alive and four had died because of distant progression. The actuarial mean OS was 28.5±1.6 months, the median was not reached. One-year and 2-year OS were 87.6±6.1%. None of the risk factors was significant in univariate analysis. Actuarial mean LC was 14.6±1.8 months (95% confidence interval [CI], 11.0 to 18.2) and median LC was 14.5±2.0 months (95% CI, 10.5 to 18.5). One-year and 2-year LC were 65.5±11.9% and 40.7±15.8%, respectively. A mild profile of toxicity was observed in the cohort of patients. Forty patients (86.9%) showed no complication (grade 0); two patients reported asthenia, six patients (13.1%) reported either pain, nausea, or vomiting. Of these six patients, five patients (10.9%) were scored as grade 1 toxicity while one patient (2.2%) was scored as grade 2. Conclusion Stereotactic body radiation therapy treatment provided an adequate clinical response in the management of adrenal gland metastases. PMID:27121718

  15. Stereotactic PET atlas of the human brain: Aid for visual interpretation of functional brain images

    SciTech Connect

    Minoshima, S.; Koeppe, R.A.; Frey, A.; Ishihara, M.; Kuhl, D.E.

    1994-06-01

    In the routine analysis of functional brain images obtained by PET, subjective visual interpretation is often used for anatomic localization. To enhance the accuracy and consistency of the anatomic interpretation, a PET stereotactic atlas and localization approach was designed for functional brain images. The PET atlas was constructed from a high-resolution [{sup 18}F]fluorodeoxyglucose (FDG) image set of a normal volunteer (a 41-yr-ld woman). The image set was reoriented stereotactically, according to the intercommissural (anterior and posterior commissures) line and transformed to the standard stereotactic atlas coordinates. Cerebral structures were annotated on the transaxial planes using a proportional grid system and surface-rendered images. The stereotactic localization technique was applied to image sets from patients with Alzheimer`s disease, and areas of functional alteration were localized visually by referring to the PET atlas. Major brain structures were identified on both transaxial planes and surface-rendered images. In the stereotactic system, anatomic correspondence between the PET atlas and stereotactically reoriented individual image sets of patients with Alzheimer`s disease facilitated both indirect and direct localization of the cerebral structures. Because rapid stereotactic alignment methods for PET images are now available for routine use, the PET atlas will serve as an aid for visual interpretation of functional brain images in the stereotactic system. Widespread application of stereotactic localization may be used in functional brain images, not only in the research setting, but also in routine clinical situations. 41 refs., 3 figs.

  16. Probabilities of Radiation Myelopathy Specific to Stereotactic Body Radiation Therapy to Guide Safe Practice

    SciTech Connect

    Sahgal, Arjun; Weinberg, Vivian; Ma, Lijun; Chang, Eric; Chao, Sam; Muacevic, Alexander; Gorgulho, Alessandra; Soltys, Scott; Gerszten, Peter C.; Ryu, Sam; Angelov, Lilyana; Gibbs, Iris; Wong, C. Shun; Larson, David A.

    2013-02-01

    Purpose: Dose-volume histogram (DVH) results for 9 cases of post spine stereotactic body radiation therapy (SBRT) radiation myelopathy (RM) are reported and compared with a cohort of 66 spine SBRT patients without RM. Methods and Materials: DVH data were centrally analyzed according to the thecal sac point maximum (Pmax) volume, 0.1- to 1-cc volumes in increments of 0.1 cc, and to the 2 cc volume. 2-Gy biologically equivalent doses (nBED) were calculated using an {alpha}/{beta} = 2 Gy (units = Gy{sub 2/2}). For the 2 cohorts, the nBED means and distributions were compared using the t test and Mann-Whitney test, respectively. Significance (P<.05) was defined as concordance of both tests at each specified volume. A logistic regression model was developed to estimate the probability of RM using the dose distribution for a given volume. Results: Significant differences in both the means and distributions at the Pmax and up to the 0.8-cc volume were observed. Concordant significance was greatest for the Pmax volume. At the Pmax volume the fit of the logistic regression model, summarized by the area under the curve, was 0.87. A risk of RM of 5% or less was observed when limiting the thecal sac Pmax volume doses to 12.4 Gy in a single fraction, 17.0 Gy in 2 fractions, 20.3 Gy in 3 fractions, 23.0 Gy in 4 fractions, and 25.3 Gy in 5 fractions. Conclusion: We report the first logistic regression model yielding estimates for the probability of human RM specific to SBRT.

  17. Ipilimumab with Stereotactic Ablative Radiation Therapy: Phase I Results and Immunologic Correlates from Peripheral T Cells.

    PubMed

    Tang, Chad; Welsh, James W; de Groot, Patricia; Massarelli, Erminia; Chang, Joe Y; Hess, Kenneth R; Basu, Sreyashi; Curran, Michael A; Cabanillas, Maria E; Subbiah, Vivek; Fu, Siqing; Tsimberidou, Apostolia M; Karp, Daniel; Gomez, Daniel R; Diab, Adi; Komaki, Ritsuko; Heymach, John V; Sharma, Padmanee; Naing, Aung; Hong, David S

    2017-03-15

    Purpose: Little prospective data are available on clinical outcomes and immune correlates from combination radiation and immunotherapy. We conducted a phase I trial (NCT02239900) testing stereotactic ablative radiotherapy (SABR) with ipilimumab.Experimental Design: SABR was given either concurrently (1 day after the first dose) or sequentially (1 week after the second dose) with ipilimumab (3 mg/kg every 3 weeks for 4 doses) to five treatment groups: concurrent 50 Gy (in 4 fractions) to liver; sequential 50 Gy (in 4 fractions) to liver; concurrent 50 Gy (in 4 fractions) to lung; sequential 50 Gy (in 4 fractions) to lung; and sequential 60 Gy (in 10 fractions) to lung or liver. MTD was determined with a 3 + 3 dose de-escalation design. Immune marker expression was assessed by flow cytometry.Results: Among 35 patients who initiated ipilimumab, 2 experienced dose-limiting toxicity and 12 (34%) grade 3 toxicity. Response outside the radiation field was assessable in 31 patients. Three patients (10%) exhibited partial response and 7 (23%) experienced clinical benefit (defined as partial response or stable disease lasting ≥6 months). Clinical benefit was associated with increases in peripheral CD8(+) T cells, CD8(+)/CD4(+) T-cell ratio, and proportion of CD8(+) T cells expressing 4-1BB and PD1. Liver (vs. lung) irradiation produced greater T-cell activation, reflected as increases in the proportions of peripheral T cells expressing ICOS, GITR, and 4-1BB.Conclusions: Combining SABR and ipilimumab was safe with signs of efficacy, peripheral T-cell markers may predict clinical benefit, and systemic immune activation was greater after liver irradiation. Clin Cancer Res; 23(6); 1388-96. ©2016 AACR.

  18. Lung Density Changes After Stereotactic Radiotherapy: A Quantitative Analysis in 50 Patients

    SciTech Connect

    Palma, David A.; Soernsen de Koste, John van; Verbakel, Wilko F.A.R.; Vincent, Andrew; Senan, Suresh

    2011-11-15

    Purpose: Radiologic lung density changes are observed in more than 50% of patients after stereotactic body radiotherapy (SBRT) for lung cancer. We studied the relationship between SBRT dose and posttreatment computed tomography (CT) density changes, a surrogate for lung injury. Methods and Materials: The SBRT fractionation schemes used to treat Stage I lung cancer with RapidArc were three fractions of 18 Gy, five fractions of 11 Gy, or eight fractions of 7.5 Gy, prescribed at the 80% isodose. Follow-up CT scans performed at less than 6 months (n = 50) and between 6 and 9 months (n = 30) after SBRT were reviewed. Posttreatment scans were coregistered with baseline scans using a B-spline deformable registration algorithm. Voxel-Hounsfield unit histograms were created for doses between 0.5 and 50 Gy. Linear mixed effects models were used to assess the effects of SBRT dose on CT density, and the influence of possible confounders was tested. Results: Increased CT density was associated with higher dose, increasing planning target volume size, and increasing time after SBRT (all p < 0.0001). Density increases were apparent in areas receiving >6 Gy, were most prominent in areas receiving >20 Gy, and seemed to plateau above 40 Gy. In regions receiving >36 Gy, the reduction in air-filled fraction of lung after treatment was up to 18%. No increase in CT density was observed in the contralateral lung receiving {>=}3 Gy. Conclusions: A dose-response relationship exists for quantitative CT density changes after SBRT. A threshold of effect is seen at low doses, and a plateau at highest doses.

  19. Stereotactic radiosurgery with the linear accelerator: treatment of arteriovenous malformations.

    PubMed

    Betti, O O; Munari, C; Rosler, R

    1989-03-01

    An original stereotactic radiosurgical approach coupling a) Talairach's stereotactic methodology, b) a specially devised mechanical system, and c) a linear accelerator is detailed. The authors present their preliminary results on 66 patients with nonsurgical intracranial arteriovenous malformations. The doses delivered for treatment varied from 20 to 70 Gy. Doses of no more than 40 Gy were used in 80% of patients. An angiographic study was performed when the computed tomographic scan controls showed relevant modifications of the lesion volume. Total obliteration was obtained in 27 of the 41 patients (65.8%) who were followed up for at least 24 months. The percentage of the cured patients is significantly higher when a) the entire malformation is included in the 75% isodose (96%) and b) the maximum diameter of the lesion is less than 12 mm (81%). Two patients died of rebleeding at 18 and 29 months after treatment.

  20. Multimodality stereotactic brain tissue identification: the NASA smart probe project

    NASA Technical Reports Server (NTRS)

    Andrews, R.; Mah, R.; Aghevli, A.; Freitas, K.; Galvagni, A.; Guerrero, M.; Papsin, R.; Reed, C.; Stassinopoulos, D.

    1999-01-01

    Real-time tissue identification can benefit procedures such as stereotactic brain biopsy, functional neurosurgery and brain tumor excision. Optical scattering spectroscopy has been shown to be effective at discriminating cancer from noncancerous conditions in the colon, bladder and breast. The NASA Smart Probe extends the concept of 'optical biopsy' by using neural network techniques to combine the output from 3 microsensors contained within a cannula 2. 7 mm in diameter (i.e. the diameter of a stereotactic brain biopsy needle). Experimental data from 5 rats show the clear differentiation between tissues such as brain, nerve, fat, artery and muscle that can be achieved with optical scattering spectroscopy alone. These data and previous findings with other modalities such as (1) analysis of the image from a fiberoptic neuroendoscope and (2) the output from a microstrain gauge suggest the Smart Probe multiple microsensor technique shows promise for real-time tissue identification in neurosurgical procedures. Copyright 2000 S. Karger AG, Basel.

  1. Extrapolation of Normal Tissue Complication Probability for Different Fractionations in Liver Irradiation

    SciTech Connect

    Tai An; Erickson, Beth; Li, X. Allen

    2009-05-01

    Purpose: The ability to predict normal tissue complication probability (NTCP) is essential for NTCP-based treatment planning. The purpose of this work is to estimate the Lyman NTCP model parameters for liver irradiation from published clinical data of different fractionation regimens. A new expression of normalized total dose (NTD) is proposed to convert NTCP data between different treatment schemes. Method and Materials: The NTCP data of radiation- induced liver disease (RILD) from external beam radiation therapy for primary liver cancer patients were selected for analysis. The data were collected from 4 institutions for tumor sizes in the range of of 8-10 cm. The dose per fraction ranged from 1.5 Gy to 6 Gy. A modified linear-quadratic model with two components corresponding to radiosensitive and radioresistant cells in the normal liver tissue was proposed to understand the new NTD formalism. Results: There are five parameters in the model: TD{sub 50}, m, n, {alpha}/{beta} and f. With two parameters n and {alpha}/{beta} fixed to be 1.0 and 2.0 Gy, respectively, the extracted parameters from the fitting are TD{sub 50}(1) = 40.3 {+-} 8.4Gy, m =0.36 {+-} 0.09, f = 0.156 {+-} 0.074 Gy and TD{sub 50}(1) = 23.9 {+-} 5.3Gy, m = 0.41 {+-} 0.15, f = 0.0 {+-} 0.04 Gy for patients with liver cirrhosis scores of Child-Pugh A and Child-Pugh B, respectively. The fitting results showed that the liver cirrhosis score significantly affects fractional dose dependence of NTD. Conclusion: The Lyman parameters generated presently and the new form of NTD may be used to predict NTCP for treatment planning of innovative liver irradiation with different fractionations, such as hypofractioned stereotactic body radiation therapy.

  2. Anti-PD-1 Blockade and Stereotactic Radiation Produce Long-Term Survival in Mice With Intracranial Gliomas

    SciTech Connect

    Zeng, Jing; See, Alfred P.; Phallen, Jillian; Jackson, Christopher M.; Belcaid, Zineb; Ruzevick, Jacob; Durham, Nicholas; Meyer, Christian; Harris, Timothy J.; Albesiano, Emilia; Pradilla, Gustavo; Ford, Eric; Wong, John; Hammers, Hans-Joerg; Mathios, Dimitris; Tyler, Betty; Brem, Henry; Tran, Phuoc T.; Pardoll, Drew; Drake, Charles G.; and others

    2013-06-01

    Purpose: Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults, and radiation is one of the main treatment modalities. However, cure rates remain low despite best available therapies. Immunotherapy is a promising modality that could work synergistically with radiation, which has been shown to increase antigen presentation and promote a proinflammatory tumor microenvironment. Programmed-death-1 (PD-1) is a surface receptor expressed on activated and exhausted T cells, which mediate T cell inhibition upon binding with its ligand PD-L1, expressed on many tumor types including human GBMs. We tested the combination of anti-PD-1 immunotherapy with stereotactic radiosurgery in a mouse orthotopic GBM model. Methods and Materials: We performed intracranial implantation of mouse glioma cell line GL261 transfected with luciferase into C57BL/6 mice. Mice were stratified into 4 treatment groups: (1) control; (2) radiation only; (3) anti-PD-1 antibody only; and (4) radiation plus anti-PD-1 antibody. Overall survival was quantified. The mice were killed on day 21 after implantation to assess immunologic parameters in the brain/tumor, cervical lymph nodes, and spleen. Results: Improved survival was demonstrated with combination anti-PD-1 therapy plus radiation compared with either modality alone: median survival was 25 days in the control arm, 27 days in the anti-PD-1 antibody arm, 28 days in the radiation arm, and 53 days in the radiation plus anti-PD-1 therapy arm (P<.05 by log-rank Mantle-Cox). Long-term survival was seen only in the combined treatment arm, with a fraction (15%-40%) of animals alive at day 180+ after treatment. Immunologic data on day 21 after implantation showed increased tumor infiltration by cytotoxic T cells (CD8+/interferon-γ+/tumor necrosis factor-α+) and decreased regulatory T cells (CD4+/FOXP3) in the combined treatment group compared with the single modality arms. Conclusions: The combination of PD-1 blockade and localized

  3. Outcomes of Stereotactic Ablative Radiotherapy in Patients With Potentially Operable Stage I Non-Small Cell Lung Cancer

    SciTech Connect

    Lagerwaard, Frank J.; Verstegen, Naomi E.; Haasbeek, Cornelis J.A.; Slotman, Ben J.; Paul, Marinus A.; Smit, Egbert F.; Senan, Suresh

    2012-05-01

    Background: Approximately two-thirds of patients with early-stage non-small-cell lung cancer (NSCLC) in The Netherlands currently undergo surgical resection. As an increasing number of fit patients have elected to undergo stereotactic ablative radiotherapy (SABR) in recent years, we studied outcomes after SABR in patients with potentially operable stage I NSCLC. Methods and Materials: In an institutional prospective database collected since 2003, 25% of lung SABR cases (n = 177 patients) were found to be potentially operable when the following patients were excluded: those with (1) synchronous lung tumors or other malignancy, (2) prior high-dose radiotherapy/pneumonectomy, (3) chronic obstructive pulmonary disease with a severity score of 3-4 according to the Global initiative for Obstructive Lung Disease classification. (4) a performance score of {>=}3, and (5) other comorbidity precluding surgery. Study patients included 101 males and 76 females, with a median age of 76 years old, 60% of whom were staged as T1 and 40% of whom were T2. Median Charlson comorbidity score was 2 (range, 0-5). A SABR dose of 60 Gy was delivered using a risk-adapted scheme in 3, 5, or 8 fractions, depending on tumor size and location. Follow-up chest computed tomography scans were obtained at 3, 6, and 12 months and yearly thereafter. Results: Median follow-up was 31.5 months; and median overall survival (OS) was 61.5 months, with 1- and 3-year survival rates of 94.7% and 84.7%, respectively. OS rates at 3 years in patients with (n = 59) and without (n = 118) histological diagnosis did not differ significantly (96% versus 81%, respectively, p = 0.39). Post-SABR 30-day mortality was 0%, while predicted 30-day mortality for a lobectomy, derived using the Thoracoscore predictive model (Falcoz PE et al. J Thorac Cardiovasc Surg 2007;133:325-332), would have been 2.6%. Local control rates at 1 and 3 years were 98% and 93%, respectively. Regional and distant failure rates at 3 years were each

  4. OP09STEREOTACTIC RADIOSURGERY FOR BRAIN METASTASES AT THE CHRISTIE AT SALFORD ROYAL HOSPITAL: OUR TWO-YEAR EXPERIENCE

    PubMed Central

    Helbrow, J.; McBain, C.; Gattamaneni, R.; Tran, A.; McCarthy, C.; Edwards, R.; Redikin, J.; Handley, J.; O'Hara, C.; Kennedy, J.; Mills, S.; Soh, C.; Leggate, J.; Whitfield, G.

    2014-01-01

    INTRODUCTION: Stereotactic radiosurgery (SRS) for brain metastases (BMs) commenced at The Christie at Salford in Dec 11 using the Novalis TxTM and BrainLab ExacTrac® system. We report our first 2 years' data. METHOD: Patients meeting NHS commissioning criteria were referred via MDT for assessment and if suitable consent. We used the BrainLab mask, CT and MRI. Gross tumour volumes (GTVs) were grown by 2mm if <4cm3 and by 1mm if >4cm3 to a planning target volume. The dose to the 80% isodose was 21Gy/1 fraction(#), 18Gy/1# and 25.5Gy/3# alternate days for PTVs <7cm3, 7-13cm3 and >13cm3 respectively and 30Gy/5# on alternate days to the 90% isodose in critical locations or where organ at risk constraints were exceeded. Follow up was 3-monthly with MRI and clinic review. Radiological response was classified as complete, unequivocal, enlargement consistent with treatment, enlargement suspicious of progression or unequivocal progression. RESULTS: Between Dec 11-Jan 14, 89 patients were consented, 51% female. Median age was 61 years (range 16-81). Primaries included lung (34%), breast (22%) and melanoma (15%), which was controlled in 67%; 42% had no extracranial metastases. A total of 170 BMs were treated (1 a retreat); per course a median of 2 (1-5) BMs were treated with median total GTV 4.87cm3 (0.05-29.9cm3). Prescribed dose was 21Gy/1# in 101 BMs, 18Gy/1# in 43, 25.5Gy/3# in 10 and 30Gy/5# in 16. One year survival from first SRS was: overall 48% (95% CI 34%-60%), lung 39% (18%-59%), breast 89% (62%-97%) and melanoma 44% (10%-75%). CONCLUSION: Overall survival results are encouraging and suggest appropriate patient selection. More detailed analysis including toxicity and time to intracranial progression will be presented.

  5. Stereotactic body radiotherapy in lung cancer: an update *

    PubMed Central

    Abreu, Carlos Eduardo Cintra Vita; Ferreira, Paula Pratti Rodrigues; de Moraes, Fabio Ynoe; Neves, Wellington Furtado Pimenta; Gadia, Rafael; Carvalho, Heloisa de Andrade

    2015-01-01

    Abstract For early-stage lung cancer, the treatment of choice is surgery. In patients who are not surgical candidates or are unwilling to undergo surgery, radiotherapy is the principal treatment option. Here, we review stereotactic body radiotherapy, a technique that has produced quite promising results in such patients and should be the treatment of choice, if available. We also present the major indications, technical aspects, results, and special situations related to the technique. PMID:26398758

  6. [The "LINAC Knife": stereotactic radiotherapy with a linear accelerator].

    PubMed

    Vetterli, D; Born, E J; Curschmann, J

    1998-07-01

    Stereotactic radiosurgery stands for a high precision irradiation concept, which allows to deliver a high dose of ionizing radiation to the tumor volume. The characteristic steep dose fall-off immediately outside the target volume enables the selective destruction of small intracranial tumors while sharply minimizing the dose to the surrounding healthy tissue. This treatment modality is non-invasive and in general well tolerated with minimal side-effects. Especially for palliative concepts the short treatment time is of great importance.

  7. Prognostic impact of average iodine density assessed by dual-energy spectral imaging for predicting lung tumor recurrence after stereotactic body radiotherapy.

    PubMed

    Aoki, Masahiko; Hirose, Katsumi; Sato, Mariko; Akimoto, Hiroyoshi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Fujioka, Ichitaro; Tanaka, Mitsuki; Ono, Shuichi; Takai, Yoshihiro

    2016-07-01

    The purpose of this study was to investigate the prognostic significance of average iodine density as assessed by dual-energy computed tomography (DE-CT) for lung tumors treated with stereotactic body radiotherapy (SBRT). From March 2011 to August 2014, 93 medically inoperable patients with 74 primary lung cancers and 19 lung metastases underwent DE-CT prior to SBRT of a total dose of 45-60 Gy in 5-10 fractions. Of these 93 patients, nine patients had two lung tumors. Thus, 102 lung tumors were included in this study. DE-CT was performed for pretreatment evaluation. Regions of interest were set for the entire tumor, and average iodine density was obtained using a dedicated imaging software and evaluated with regard to local control. The median follow-up period was 23.4 months (range, 1.5-54.5 months). The median value of the average iodine density was 1.86 mg/cm(3) (range, 0.40-9.27 mg/cm(3)). Two-year local control rates for the high and low average iodine density groups divided by the median value of the average iodine density were 96.9% and 75.7% (P = 0.006), respectively. Tumors with lower average iodine density showed a worse prognosis, possibly reflecting a hypoxic cell population in the tumor. The average iodine density exhibited a significant impact on local control. Our preliminary results indicate that iodine density evaluated using dual-energy spectral CT may be a useful, noninvasive and quantitative assessment of radio-resistance caused by presumably hypoxic cell populations in tumors.

  8. Incidence and Predictive Factors of Pain Flare After Spine Stereotactic Body Radiation Therapy: Secondary Analysis of Phase 1/2 Trials

    SciTech Connect

    Pan, Hubert Y.; Allen, Pamela K.; Wang, Xin S.; Chang, Eric L.; Rhines, Laurence D.; Tatsui, Claudio E.; Amini, Behrang; Wang, Xin A.; Tannir, Nizar M.; Brown, Paul D.; Ghia, Amol J.

    2014-11-15

    Purpose/Objective(s): To perform a secondary analysis of institutional prospective spine stereotactic body radiation therapy (SBRT) trials to investigate posttreatment acute pain flare. Methods and Materials: Medical records for enrolled patients were reviewed. Study protocol included baseline and follow-up surveys with pain assessment by Brief Pain Inventory and documentation of pain medications. Patients were considered evaluable for pain flare if clinical note or follow-up survey was completed within 2 weeks of SBRT. Pain flare was defined as a clinical note indicating increased pain at the treated site or survey showing a 2-point increase in worst pain score, a 25% increase in analgesic intake, or the initiation of steroids. Binary logistic regression was used to determine predictive factors for pain flare occurrence. Results: Of the 210 enrolled patients, 195 (93%) were evaluable for pain flare, including 172 (88%) clinically, 135 (69%) by survey, and 112 (57%) by both methods. Of evaluable patients, 61 (31%) had undergone prior surgery, 57 (29%) had received prior radiation, and 34 (17%) took steroids during treatment, mostly for prior conditions. Pain flare was observed in 44 patients (23%). Median time to pain flare was 5 days (range, 0-20 days) after the start of treatment. On multivariate analysis, the only independent factor associated with pain flare was the number of treatment fractions (odds ratio = 0.66, P=.004). Age, sex, performance status, spine location, number of treated vertebrae, prior radiation, prior surgery, primary tumor histology, baseline pain score, and steroid use were not significant. Conclusions: Acute pain flare after spine SBRT is a relatively common event, for which patients should be counseled. Additional study is needed to determine whether prophylactic or symptomatic intervention is preferred.

  9. Cost-Effectiveness Analysis of Stereotactic Body Radiotherapy and Radiofrequency Ablation for Medically Inoperable, Early-Stage Non-Small Cell Lung Cancer

    SciTech Connect

    Sher, David J.

    2011-12-01

    Purpose: The standard management of medically inoperable Stage I non-small-cell lung cancer (NSCLC) conventionally has been fractionated three-dimensional conformal radiation therapy (3D-CRT). The relatively poor local control rate and inconvenience associated with this therapy have prompted the development of stereotactic body radiotherapy (SBRT), a technique that delivers very high doses of irradiation typically over 3 to 5 sessions. Radiofrequency ablation (RFA) has also been investigated as a less costly, single-day therapy that thermally ablates small, peripheral tumors. The cost-effectiveness of these three techniques has never been compared. Methods and Materials: We developed a Markov model to describe health states of 65-year-old men with medically inoperable NSCLC after treatment with 3D-CRT, SBRT, and RFA. Given their frail state, patients were assumed to receive supportive care after recurrence. Utility values, recurrence risks, and costs were adapted from the literature. Sensitivity analyses were performed to model uncertainty in these parameters. Results: The incremental cost-effectiveness ratio for SBRT over 3D-CRT was $6,000/quality-adjusted life-year, and the incremental cost-effectiveness ratio for SBRT over RFA was $14,100/quality-adjusted life-year. One-way sensitivity analysis showed that the results were robust across a range of tumor sizes, patient utility values, and costs. This result was confirmed with probabilistic sensitivity analyses that varied local control rates and utilities. Conclusion: In comparison to 3D-CRT and RFA, SBRT was the most cost-effective treatment for medically inoperable NSCLC over a wide range of treatment and disease assumptions. On the basis of efficacy and cost, SBRT should be the primary treatment approach for this disease.

  10. Prognostic impact of average iodine density assessed by dual-energy spectral imaging for predicting lung tumor recurrence after stereotactic body radiotherapy

    PubMed Central

    Aoki, Masahiko; Hirose, Katsumi; Sato, Mariko; Akimoto, Hiroyoshi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Fujioka, Ichitaro; Tanaka, Mitsuki; Ono, Shuichi; Takai, Yoshihiro

    2016-01-01

    The purpose of this study was to investigate the prognostic significance of average iodine density as assessed by dual-energy computed tomography (DE-CT) for lung tumors treated with stereotactic body radiotherapy (SBRT). From March 2011 to August 2014, 93 medically inoperable patients with 74 primary lung cancers and 19 lung metastases underwent DE-CT prior to SBRT of a total dose of 45–60 Gy in 5–10 fractions. Of these 93 patients, nine patients had two lung tumors. Thus, 102 lung tumors were included in this study. DE-CT was performed for pretreatment evaluation. Regions of interest were set for the entire tumor, and average iodine density was obtained using a dedicated imaging software and evaluated with regard to local control. The median follow-up period was 23.4 months (range, 1.5–54.5 months). The median value of the average iodine density was 1.86 mg/cm3 (range, 0.40–9.27 mg/cm3). Two-year local control rates for the high and low average iodine density groups divided by the median value of the average iodine density were 96.9% and 75.7% (P = 0.006), respectively. Tumors with lower average iodine density showed a worse prognosis, possibly reflecting a hypoxic cell population in the tumor. The average iodine density exhibited a significant impact on local control. Our preliminary results indicate that iodine density evaluated using dual-energy spectral CT may be a useful, noninvasive and quantitative assessment of radio-resistance caused by presumably hypoxic cell populations in tumors. PMID:26826198

  11. Assessing the Need for Adjuvant Chemotherapy After Stereotactic Body Radiation Therapy in Early-stage Non-small Cell Lung Carcinoma

    PubMed Central

    Bahig, Houda; Filion, Édith; Campeau, Marie-Pierre; Lambert, Louise; Roberge, David; Gorgos, Andrei-Bogdan; Vu, Toni

    2016-01-01

    Purpose Surgery remains the standard treatment for medically operable patients with early-stage non-small cell lung carcinoma (NSCLC). Following surgical resection, adjuvant chemotherapy is recommended for large tumors >4 cm. For unfit patients, stereotactic body radiation therapy (SBRT) has emerged as an excellent alternative to surgery. This study aims to assess patterns of recurrence and discuss the role of chemotherapy after SBRT for NSCLC. Methods We reviewed patients treated with SBRT for primary early-stage NSCLC between 2009 and 2015. Total target doses were between 50 and 60 Gy administered in three to eight fractions. All patients had a staging fluorodeoxyglucose (FDG) positron emission tomography (PET) integrated with computed tomography (CT) scan, and histologic confirmation was obtained whenever possible. Mediastinal staging was performed if lymph node involvement was suspected on CT or PET/CT. Survival outcomes were estimated using the Kaplan-Meier method. Results Among the 559 early-stage NSCLC patients treated with SBRT, 121 patients were stage T2N0. The one-year and three-year overall survival rates were 88% and 70%, respectively, for patients with T2 disease, compared to 95% and 81%, respectively, for the T1 patients (p<0.05). The one-year and three-year local control rates were equal in both groups (98% and 91%, respectively). In T2 patients, 25 (21%) presented a relapse, among which 21 (84%) were nodal or distant. The median survival of T2N0 patients following a relapse was 11 months. Conclusion Lung SBRT provides high local control rates, even for larger tumors. When patients relapse, the majority of them do so at regional or distant sites. These results raise the question as to whether adjuvant treatment should be considered following SBRT for larger tumors.  PMID:28070470

  12. Stereotactic radiofrequency thermocoagulation for hypothalamic hamartoma with intractable gelastic seizures.

    PubMed

    Homma, Junpei; Kameyama, Shigeki; Masuda, Hiroshi; Ueno, Takehiko; Fujimoto, Ayataka; Oishi, Makoto; Fukuda, Masafumi

    2007-08-01

    Management of hypothalamic hamartoma with intractable gelastic epilepsy remains controversial. We have used stereotactic thermocoagulation for treatment of hypothalamic hamartoma with intractable gelastic epilepsy since 1997. Herein, we review our experience in five cases to clarify the usefulness of this treatment. A total of five patients with hypothalamic hamartoma were treated by stereotactic thermocoagulation at our hospital during the period October 1997 through February 2004. In all patients, the hamartoma was less than 10mm in diameter and was located on the floor of the third ventricle with sessile attachment to the wall. To identify ictal onset, chronic intracranial electroencephalography was performed in three patients with the use of a depth electrode implanted in the hamartoma. Attempts were made to induce gelastic seizure by electrical stimulation of the hamartoma in three patients. After magnetic resonance imaging-guided targeting, radiofrequency thermocoagulation of the boundary between the hamartoma and normal hypothalamus was performed to achieve disconnection effects. Marked reductions in seizure frequency were obtained in all cases, with three patients becoming seizure-free after the procedure. No intraoperative complications occurred except in one patient who experienced acute and transient panidrosis with hot flushes during coagulation. Our results suggest that stereotactic thermocoagulation of hypothalamic hamartoma is an acceptable treatment option for patients with intractable gelastic seizures.

  13. CT Imaging Findings after Stereotactic Radiotherapy for Liver Tumors

    PubMed Central

    Brook, Olga R.; Thornton, Eavan; Mendiratta-Lala, Mishal; Mahadevan, Anand; Raptopoulos, Vassilious; Brook, Alexander; Najarian, Robert; Sheiman, Robert; Siewert, Bettina

    2015-01-01

    Purpose. To study radiological response to stereotactic radiotherapy for focal liver tumors. Materials and Methods. In this IRB-approved, HIPAA-compliant study CTs of 68 consecutive patients who underwent stereotactic radiotherapy for liver tumors between 01/2006 and 01/2010 were retrospectively reviewed. Two independent reviewers evaluated lesion volume and enhancement pattern of the lesion and of juxtaposed liver parenchyma. Results. 36 subjects with hepatocellular carcinoma (HCC), 25 with liver metastases, and seven with cholangiocarcinoma (CCC) were included in study. Mean follow-up time was 5.6 ± 7.1 months for HCC, 6.4 ± 5.1 months for metastases, and 10.1 ± 4.8 months for the CCC. Complete response was seen in 4/36 (11.1%) HCCs and 1/25 (4%) metastases. Partial response (>30% decrease in long diameter) was seen in 25/36 (69%) HCCs, 14/25 (58%) metastases, and 7/7 (100%) of CCCs. Partial response followed by local recurrence (>20% increase in long diameter from nadir) occurred in 2/36 (6%) HCCs and 4/25 (17%) metastases. Liver parenchyma adjacent to the lesion demonstrated a prominent halo of delayed enhancement in 27/36 (78%) of HCCs, 19/21 (91%) of metastases, and 7/7 (100%) of CCCs. Conclusion. Sustainable radiological partial response to stereotactic radiotherapy is most frequent outcome seen in liver lesions. Prominent halo of delayed enhancement of the adjacent liver is frequent finding. PMID:26221135

  14. Extracranial stereotactic radiotherapy: evaluation of PTV coverage and dose conformity.

    PubMed

    Hädinger, Ulrich; Thiele, Wibke; Wulf, Jörn

    2002-01-01

    During the past few years the concept of cranial stereotactic radiotherapy has been successfully extended to extracranial tumoral targets. In our department, hypofractionated treatment of tumours in lung, liver, abdomen, and pelvis is performed in the Stereotactic Body Frame (ELEKTA Instrument AB) since 1997. We present the evaluation of 63 consecutively treated targets (22 lung, 21 liver, 20 abdomen/pelvis) in 58 patients with respect to dose coverage of the planning target volume (PTV) as well as conformity of the dose distribution. The mean PTV coverage was found to be 96.3% +/- 2.3% (lung), 95.0% +/- 4.5% (liver), and 92.1% +/- 5.2% (abdomen/pelvis). For the so-called conformation number we obtained values of 0.73 +/- 0.09 (lung), 0.77 +/- 0.10 (liver), and 0.70 +/- 0.08 (abdomen/pelvis). The results show that highly conformal treatment techniques can be applied also in extracranial stereotactic radiotherapy. This is primarily due to the relatively simple geometrical shape of most of the targets. Especially lung and liver targets turned out to be approximately spherically/cylindrically shaped, so that the dose distribution can be easily tailored by rotational fields.

  15. Anniversary Paper: The role of medical physicists in developing stereotactic radiosurgery

    SciTech Connect

    Benedict, Stanley H.; Bova, Frank J.; Clark, Brenda; Goetsch, Steven J.; Hinson, William H.; Leavitt, Dennis D.; Schlesinger, David J.; Yenice, Kamil M.

    2008-09-15

    This article is a tribute to the pioneering medical physicists over the last 50 years who have participated in the research, development, and commercialization of stereotactic radiosurgery (SRS) and stereotactic radiotherapy utilizing a wide range of technology. The authors have described the evolution of SRS through the eyes of physicists from its beginnings with the Gamma Knife in 1951 to proton and charged particle therapy; modification of commercial linacs to accommodate high precision SRS setups; the multitude of accessories that have enabled fine tuning patients for relocalization, immobilization, and repositioning with submillimeter accuracy; and finally the emerging technology of SBRT. A major theme of the article is the expanding role of the medical physicist from that of advisor to the neurosurgeon to the current role as a primary driver of new technology that has already led to an adaptation of cranial SRS to other sites in the body, including, spine, liver, and lung. SRS continues to be at the forefront of the impetus to provide technological precision for radiation therapy and has demonstrated a host of downstream benefits in improving delivery strategies for conventional therapy as well. While this is not intended to be a comprehensive history, and the authors could not delineate every contribution by all of those working in the pursuit of SRS development, including physicians, engineers, radiobiologists, and the rest of the therapy and dosimetry staff in this important and dynamic radiation therapy modality, it is clear that physicists have had a substantial role in the development of SRS and theyincreasingly play a leading role in furthering SRS technology.

  16. Time- and Dose-Dependency of Radiographic Normal Tissue Changes of the Lung After Stereotactic Radiotherapy

    SciTech Connect

    Hof, Holger; Zgoda, Jacqueline; Nill, Simeon; Hoess, Angelika; Kopp-Schneider, Annette; Herfarth, Klaus; Debus, Juergen; Plathow, Christian

    2010-08-01

    Purpose: Normal tissue changes (NTC) of the normal lung parenchyma are commonly seen after stereotactic single-dose radiotherapy (radiosurgery) of lung tumors. The aim of this study was to investigate the extent and dynamics of NTCs after radiosurgery. Methods and Materials: Fifty lung tumors in 49 patients were treated with radiosurgery. Follow-up CTs were anatomically matched to the treatment planning CTs, incorporating the treatment plan and enabling spatial correlation of initial radiation dose distribution and subsequent NTCs of the lung. Lung parenchyma was divided into nine areas of different radiation dose exposures (range, 6-35 Gy). Areas were investigated and compared at different time points according to the development of NTCs. Results: Twenty-six patients developed NTCs during follow-up. The evaluation of the dependency of the extent of NTCs on the amount of radiation dose lead to a linear model for the fixed effects: Fraction of reacting volume =Intercept{sub T} +0.0208 * Dose ('Dose' should be given in Gy). Dose had a slope of 0.0208 (fraction of normal tissue reaction/Gy) (SE 0.000804, p < 0.0001), implying a significant correlation between dose level and the extent of NTC. Conclusion: For radiosurgery of lung tumors, a significant correlation of radiation dose and the extent of NTCs could be demonstrated. Using the introduced formula, a preview on the extent of NTCs to develop in normal lung parenchyma according to the dose level can be performed.

  17. Postoperative modified stereotactic radiotherapy using a micro-multileaf collimator in patients with malignant glioma.

    PubMed

    Isaka, Toshihiko; Nishiyama, Kinji; Nakagawa, Hidemitsu; Suzuki, Tsuyoshi; Wada, Kouichi

    2002-06-01

    To achieve local control of malignant glioma, we designed a postoperative stereotactic radiotherapy using a micro-multileaf collimator (micro-MLC). The purpose of this study was to clarify the feasibility of this treatment. The treatment was performed in six patients who met the following eligibility criteria: (1) supratentorial tumor, (2) residual tumor volume < or = 40 cm3, and (3) Karnofsky performance status > or = 70. The three planning target volumes (PTVs), which consisted of restricted PTV (RPTV), intermediate PTV (IPTV), and extended PTV (EPTV), defined as the residual tumor plus a 1 cm, 2 cm, and 3 cm margins, respectively, and total dose delivery of 60-68 Gy, 52-60 Gy, and 44-52 Gy to the isocenters of RPTV, IPTV, and EPTV, respectively, in 4 Gy per fraction at five fractions per week, were established. The beam arrangement and the conformal blockade with a micro-MLC for the optimal treatment plan were designed. The treatment plans showed the high dose conformation to EPTV, the appropriate dose gradients in the three PTVs with the high dose homogeneity to RPTV, and the tolerated dose to critical structures. Following the plans, treatment was performed. The clinical findings more than 12 months after the treatment supported its possible use. We conclude that this treatment is feasible at least in selected patients.

  18. Fast Arc Delivery for Stereotactic Body Radiotherapy of Vertebral and Lung Tumors

    SciTech Connect

    Ong, Chin Loon; Verbakel, Wilko F.A.R.; Dahele, Max; Cuijpers, Johan P.; Slotman, Ben J.; Senan, Suresh

    2012-05-01

    Purpose: Flattening filter-free (FFF) beams with higher dose rates and faster delivery are now clinically available. The purpose of this planning study was to compare optimized non-FFF and FFF RapidArc plans for stereotactic body radiotherapy (SBRT) and to validate the accuracy of fast arc delivery. Methods and Material: Ten patients with peripheral lung tumors and 10 with vertebral metastases were planned using RapidArc with a flattened 6-MV photon beam and a 10-MV FFF beam for fraction doses of 7.5-18 Gy. Dosimetry of the target and organs at risk (OAR), number of monitor units (MU), and beam delivery times were assessed. GafChromic EBT2 film measurements of FFF plans were performed to compare calculated and delivered dose distributions. Results: No major dosimetric differences were seen between the two delivery techniques. For lung SBRT plans, conformity indices and OAR doses were similar, although the average MU required were higher with FFF plans. For vertebral SBRT, FFF plans provided comparable PTV coverage, with no significant differences in OAR doses. Average beam delivery times were reduced by a factor of up to 2.5, with all FFF fractions deliverable within 4 min. Measured FFF plans showed high agreement with calculated plans, with more than 99% of the area within the region of interest fulfilling the acceptance criterion. Conclusion: The higher dose rate of FFF RapidArc reduces delivery times significantly, without compromising plan quality or accuracy of dose delivery.

  19. 4D VMAT, gated VMAT, and 3D VMAT for stereotactic body radiation therapy in lung

    NASA Astrophysics Data System (ADS)

    Chin, E.; Loewen, S. K.; Nichol, A.; Otto, K.

    2013-02-01

    Four-dimensional volumetric modulated arc therapy (4D VMAT) is a treatment strategy for lung cancers that aims to exploit relative target and tissue motion to improve organ at risk (OAR) sparing. The algorithm incorporates the entire patient respiratory cycle using 4D CT data into the optimization process. Resulting treatment plans synchronize the delivery of each beam aperture to a specific phase of target motion. Stereotactic body radiation therapy treatment plans for 4D VMAT, gated VMAT, and 3D VMAT were generated on three patients with non-small cell lung cancer. Tumour motion ranged from 1.4-3.4 cm. The dose and fractionation scheme was 48 Gy in four fractions. A B-spline transformation model registered the 4D CT images. 4D dose volume histograms (4D DVH) were calculated from total dose accumulated at the maximum exhalation. For the majority of OARs, gated VMAT achieved the most radiation sparing but treatment times were 77-148% longer than 3D VMAT. 4D VMAT plan qualities were comparable to gated VMAT, but treatment times were only 11-25% longer than 3D VMAT. 4D VMAT's improvement of healthy tissue sparing can allow for further dose escalation. Future study could potentially adapt 4D VMAT to irregular patient breathing patterns.

  20. Dose to the intracranial arteries in stereotactic and intensity-modulated radiotherapy for skull base tumors

    SciTech Connect

    Nieder, Carsten . E-mail: cnied@hotmail.com; Grosu, Anca L.; Stark, Sybille; Wiedenmann, Nicole; Busch, Raymonde; Kneschaurek, Peter; Molls, Michael

    2006-03-15

    Purpose: To examine retrospectively the maximum dose to the large skull base/intracranial arteries in fractionated stereotactic radiotherapy (FSRT) and intensity-modulated radiotherapy (IMRT), because of the potential risk of perfusion disturbances. Methods and Materials: Overall, 56 patients with tumors adjacent to at least one major artery were analyzed. Our strategy was to perform FSRT with these criteria: 1.8 Gy per fraction, planning target volume (PTV) enclosed by the 95% isodose, maximum dose 107%. Dose limits were applied to established organs at risk, but not the vessels. If FSRT planning failed to meet any of these criteria, IMRT was planned with the same objectives. Results: In 31 patients (median PTV, 23 cm{sup 3}), the FSRT plan fulfilled all criteria. No artery received a dose {>=}105%. Twenty-five patients (median PTV, 39 cm{sup 3}) needed IMRT planning. In 11 of 25 patients (median PTV, 85 cm{sup 3}), no plan satisfying all our criteria could be calculated. Only in this group, moderately increased maximum vessel doses were observed (106-110%, n = 7, median PTV, 121 cm{sup 3}). The median PTV dose gradient was 29% (significantly different from the 14 patients with satisfactory IMRT plans). Three of the four patients in this group had paranasal sinus tumors. Conclusion: The doses to the major arteries should be calculated in IMRT planning for critical tumor locations if a dose gradient >13% within the PTV can not be avoided because the PTV is large or includes air cavities.

  1. Dosimetric comparison of stereotactic body radiotherapy for spinal metastasis in cyberknife and helical tomotherapy

    NASA Astrophysics Data System (ADS)

    Kang, Young-nam; Kay, Chul Seung; Son, Seok Hyun; Choi, Byung Ock; Jung, Ji-Young; Shin, Hun-Joo; Kay, Chul Seung; Son, Seok Hyun; Kim, Myong Ho; Seo, Jae-Hyuk; Lee, Gi Woong

    2012-12-01

    This study seeks to evaluate the stereotactic body radiation therapy (SBRT) dosimetric benefit of cyberknife (CK) and helical tomotherapy (HT) for spinal tumor patients in regards to successful plan acceptance and lower dosage to critical structures. This study used dose volume histogram (DVH) compared the two systems quantitatively, by using several indices for the dosimetric comparisons, including the conformity index (CI) and homogeneity index (HI) for the planned target volume (PTV). We planned L3 (n = 2), L5 (n = 1), T12 (n = 1), C3 (n = 1), and T5 (n = 1) spinal tumors case with planning target volumes ranging from 3.55-17.95 cc. Prescription doses were 1600 ˜ 2000 cGy per single fraction. CK prescribed 80 ˜ 85% in PTV and HT 90 ˜ 95%, respectively. The dosimetric data were compared between the two treatment systems by calculating the CI, HI, and maximum doses to the OARs based on the treatment plans, generated for each site. Regarding the homogeneity of PTV, both plans gave satisfactory results, and no significant differences were observed. The partial volume tolerance dose (received dose of 10 Gy at a spinal cord volume 10%) to the spinal cord in 16 ˜ 18 Gy single fraction was satisfactory. We found that both planning systems satisfied the required PTV prescription, but better dose conformity and better dose homogeneity with a poorer dose gradient were achieved with HT then with CK.

  2. Stereotactic ablative radiotherapy with CyberKnife for advanced thymic carcinoma: a case report.

    PubMed

    Fan, C Y; Huang, W Y; Jen, Y M; Lin, M J; Lin, K T

    2015-10-01

    Thymic carcinoma is a rare but lethal mediastinal cancer. The optimal treatment for advanced thymic carcinoma is not yet established. This report is the first known of stereotactic ablative radiotherapy (sabr) with CyberKnife (Accuray, Sunnyvale, CA, U.S.A.) as definitive therapy for thymic carcinoma. The patient, a 70-year-old woman with thymic carcinoma, invasion into neighboring organs, and pleural metastases-underwent CyberKnife sabr at 40 Gy in 5 fractions for two lesions, one in the thymus and one in the right paraspinal pleura. After 61 months of observation, a partial response was observed in the irradiated fields. However, disease progression in the non-irradiated pleura was noted. The patient underwent salvage CyberKnife sabr for the four initially nonirradiated pleural lesions. Computed tomography images obtained 10 months after the salvage therapy revealed a partial response. The patient is living, with progression-free irradiated lesions and no radiation-related toxicity. CyberKnife sabr is feasible for patients who are unable to undergo either surgery or conventionally fractionated radiation therapy.

  3. Evaluation of stereotactic body radiotherapy (SBRT) boost in the management of endometrial cancer.

    PubMed

    Demiral, S; Beyzadeoglu, M; Uysal, B; Oysul, K; Kahya, Y Elcim; Sager, O; Dincoglan, F; Gamsiz, H; Dirican, B; Surenkok, S

    2013-01-01

    The purpose of this study is to evaluate the use of linear accelerator (LINAC)-based stereotactic body radiotherapy (SBRT) boost with multileaf collimator technique after pelvic radiotherapy (RT) in patients with endometrial cancer. Consecutive patients with endometrial cancer treated using LINAC-based SBRT boost after pelvic RT were enrolled in the study. All patients had undergone surgery including total abdominal hysterectomy and bilateral salpingo-oophorectomy ± pelvic/paraortic lymphadenectomy before RT. Prescribed external pelvic RT dose was 45 Gray (Gy) in 1.8 Gy daily fractions. All patients were treated with SBRT boost after pelvic RT. The prescribed SBRT boost dose to the upper two thirds of the vagina including the vaginal vault was 18 Gy delivered in 3 fractions with 1-week intervals. Gastrointestinal and genitourinary toxicity was assessed using the Common Terminology Criteria for Adverse Events version 3 (CTCAE v3).Between April 2010 and May 2011, 18 patients with stage I-III endometrial cancer were treated with LINAC-based SBRT boost after pelvic RT. At a median follow-up of 24 (8-26) months with magnetic resonance imaging (MRI) and gynecological examination, local control rate of the study group was 100 % with negligible acute and late toxicity.LINAC-based SBRT boost to the vaginal cuff is a feasible gynecological cancer treatment modality with excellent local control and minimal toxicity that may replace traditional brachytherapy boost in the management of endometrial cancer.

  4. Increasing the Therapeutic Ratio of Stereotactic Ablative Radiotherapy by Individualized Isotoxic Dose Prescription.

    PubMed

    Zindler, Jaap D; Thomas, Charles R; Hahn, Stephen M; Hoffmann, Aswin L; Troost, Esther G C; Lambin, Philippe

    2016-02-01

    To obtain a favorable tradeoff between treatment benefits and morbidity ("therapeutic ratio"), radiotherapy (RT) dose is prescribed according to the tumor volume, with the goal of controlling the disease while respecting normal tissue tolerance levels. We propose a new paradigm for tumor dose prescription in stereotactic ablative radiotherapy (SABR) based on organ-at-risk (OAR) tolerance levels called isotoxic dose prescription (IDP), which is derived from experiences and limitations of conventionally fractionated radiotherapy. With IDP, the radiation dose is prescribed based on the predefined level of normal tissue complication probability of a nearby dose-limiting OAR at a prespecified dose-volume constraint. Simultaneously, the prescribed total tumor dose (TTD) is maximized to the technically highest achievable level in order to increase the local tumor control probability (TCP). IDP is especially relevant for tumors located at eloquent locations or for large tumors in which severe toxicity has been described. IDP will result in a lower RT dose or a treatment scheduled with more fractions if the OAR tolerance level is exceeded, and potential dose escalation occurs when the OAR tolerance level allows it and when it is expected to be beneficial (if TCP < 90%). For patients with small tumors at noneloquent sites, the current SABR dose prescription already results in high rates of local control at low toxicity rates. In this review, the concept of IDP is described in the context of SABR.

  5. Prognostic Value of MR Imaging Texture Analysis in Brain Non-Small Cell Lung Cancer Oligo-Metastases Undergoing Stereotactic Irradiation

    PubMed Central

    Tini, Paolo; Biondi, Michelangelo; Sebaste, Lucio; Vanzi, Eleonora; De Otto, Gianmarco; Rubino, Giovanni; Carfagno, Tommaso; Battaglia, Giuseppe; Pastina, Pierpaolo; Cerase, Alfonso; Mazzoni, Lorenzo Nicola; Banci Buonamici, Fabrizio; Pirtoli, Luigi

    2016-01-01

    Background  Stereotactic irradiation is widely used in brain oligo-metastases treatment. The aim of this study is to evaluate the prognostic value of magnetic resonance imaging (MRI) texture analysis (TA) of brain metastases (BM) of non-small cell lung cancer (NSCLC). Materials and methods  This study included thirty-eight consecutive patients undergoing stereotactic irradiation, that is, stereotactic fractionated radiotherapy (SRT) or radiosurgery (SRS), from January 2011 to December 2014 for 1-2 brain BM from NSCLC. Whole-brain radiotherapy (WBRT) was not delivered. The diagnostic MRI DICOM (Digital Imaging and Communications in Medicine) images were collected and analyzed with a homemade ImageJ macro, and typical TA parameters (mean, standard deviation, skewness, kurtosis, entropy, and uniformity) were evaluated for: brain progression-free survival; modality of brain metastatic progression (local progression or/and new metastases); and overall survival, after SRT/SRS. Results After SRT/SRS 14 patients (36.8%) experienced recurrence in the brain, with a recurrence in the irradiated site (five patients, 13.2%), new metastases (11 patients, 28.9%), local recurrence and new metastases (two patients, 5.25%). Nineteen patients (50%) died of tumor progression or other causes. Entropy and uniformity were significantly associated with local progression, whereas kurtosis was significantly associated with both local progression and new brain metastases. Conclusions  These results appear promising, since the knowledge of factors correlated with the modality of brain progression after stereotactic irradiation of brain oligo-metastatic foci of NSCLC might help in driving the best treatment in these patients (association of SRT/SRS with WBRT? Increase of SRT/SRS dose?). Our preliminary data needs confirmation in large patient series. PMID:27226944

  6. CyberKnife Stereotactic Ablative Radiotherapy as an Option of Treatment for Patients With Prostate Cancer Having Oligometastatic Lymph Nodes: Single-Center Study Outcome Evaluation.

    PubMed

    Napieralska, Aleksandra; Miszczyk, Leszek; Stąpór-Fudzińska, Małgorzata

    2016-10-01

    The aim of this study was to evaluate the effectiveness of CyberKnife-based stereotactic ablative radiotherapy on prostate cancer lymph node metastases. Our material consisted of 18 patients with 31 metastatic lymph nodes irradiated between 2011 and 2014 using CyberKnife-based stereotactic ablative radiotherapy. Patients were irradiated using fraction dose varied from 6 to 15 Gy (median 10), to the total dose of 24 to 45 Gy (median 30). Irradiated lymph node size varied from 0.4 to 4.0 cm. In all, 9 patients had single lymph node metastasis and 9 patients had metastases of 2 to 4 lymph nodes. Prostate-specific antigen concentration before radiotherapy varied from 0.01 to 15.58 (mean 6.97; median 4.66). All patients at the time of radiotherapy and follow-up received androgen deprivation therapy. Mann-Whitney U, Kaplan-Meier method, and log-rank tests were used in statistical analysis. We obtained the following results: after CyberKnife stereotactic ablative radiotherapy, prostate-specific antigen concentration dropped in majority of cases and during the last control varied from 0.00 to 258.00 (median 2.5), and was lower in patients without dissemination to other organs (P = .01). Complete regression was found in 12 lesions, stable disease in 13, and progression in 4. In 7 patients, the dissemination to other organs occurred. Our results allow us to conclude that CyberKnife stereotactic ablative radiotherapy of prostate cancer lymph node oligometastases gives good local control and relatively good prostate-specific antigen response.

  7. Quality assurance and commissioning of an infrared marker-based patient positioning system for frameless extracranial stereotactic radiotherapy.

    PubMed

    Gupta, Tejpal; Phurailatpam, Reena; Ajay, Mishra; Rajeshri, Pai; Pranshu, Mohindra; Supriya, Chopra

    2007-12-01

    Rapid advancements in imaging technology have led to remarkable improvements in identification and localization of tumors, ushering the era of high-precision techniques in contemporary radiotherapy practice. However, uncertainties in patient set-up and organ motion during a course of fractionated radiotherapy can compromise precision of radiation therapy. Excellent accuracy has been achieved with invasive and non-invasive fixation systems for stereotactic radiotherapy. This report describes the commissioning procedure and Quality Assurance studies done to evaluate the accuracy of isocenter localization by an infrared marker-based positioning system (ExacTrac). The ExacTrac has two infrared cameras that emit and detect infrared rays from reflective markers and construct three-dimensional coordinates of each marker. It detects the difference of the actual isocenter position from the planned isocenter coordinates in three translational (lateral, longitudinal, vertical, or x,y,z axes) and three rotational axes (six degree of freedom). This study performed on a flat and static phantom shows excellent accuracy achieved by the ExacTrac system. The positioning accuracy of ExacTrac (± 1 mm translational displacement and ± 1° rotational errors) can be a valuable tool in implementing frameless extracranial stereotactic radiotherapy. Nevertheless, it needs to be further evaluated on patients with inherent motion and greater positional uncertainty before being adopted in clinical practice.

  8. Stereotactic Body Radiation Therapy for Non-Small Cell Lung Cancer Tumors Greater Than 5 cm: Safety and Efficacy

    SciTech Connect

    Woody, Neil M. Stephans, Kevin L.; Marwaha, Gaurav; Djemil, Toufik; Videtic, Gregory M.M.

    2015-06-01

    Purpose: The purpose of this study was to determine outcomes of patients with node-negative medically inoperable non-small cell lung cancer (NSCLC) whose primary tumors exceeded 5 cm and were treated with stereotactic body radiation therapy (SBRT). Methods and Materials: We surveyed our institutional prospective lung SBRT registry to identify treated patients with tumors >5 cm. Treatment outcomes for local control (LC), locoregional control (LRC), disease-free survival (DFS), and overall survival (OS) were assessed by Kaplan-Meier estimates. Toxicities were graded according to Common Terminology Criteria for Adverse Events version 4. Mean pretreatment pulmonary function test values were compared to mean posttreatment values. Results: From December 2003 to July 2014, 40 patients met study criteria. Median follow-up was 10.8 months (range: 0.4-70.3 months). Median age was 76 years (range: 56-90 years), median body mass index was 24.3 (range: 17.7-37.2), median Karnofsky performance score was 80 (range: 60-90), and median Charlson comorbidity index score was 2 (range: 0-5). Median forced expiratory volume in 1 second (FEV1) was 1.41 L (range: 0.47-3.67 L), and median diffusion capacity (DLCO) was 47% of predicted (range: 29%-80%). All patients were staged by fluorodeoxyglucose-positron emission tomography/computed tomography staging, and 47.5% underwent mediastinal staging by endobronchial ultrasonography. Median tumor size was 5.6 cm (range: 5.1-10 cm), median SBRT dose was 50 Gy (range: 30-60 Gy) in 5 fractions (range: 3-10 fractions). Eighteen-month LC, LRC, DFS, and OS rates were 91.2%, 64.4%, 34.6%, and 59.7%, respectively. Distant failure was the predominant pattern of failure (32.5%). Three patients (7.5%) experienced grade 3 or higher toxicity. Mean posttreatment FEV1 was not significantly reduced (P=.51), but a statistically significant absolute 6.5% (P=.03) reduction in DLCO was observed. Conclusions: Lung SBRT for medically inoperable node

  9. Australia's Next Top Fraction Model

    ERIC Educational Resources Information Center

    Gould, Peter

    2013-01-01

    Peter Gould suggests Australia's next top fraction model should be a linear model rather than an area model. He provides a convincing argument and gives examples of ways to introduce a linear model in primary classrooms.

  10. Predictor of Severe Gastroduodenal Toxicity After Stereotactic Body Radiotherapy for Abdominopelvic Malignancies

    SciTech Connect

    Bae, Sun Hyun; Kim, Mi-Sook; Cho, Chul Koo; Kang, Jin-Kyu; Lee, Sang Yeob; Lee, Kyung-Nam; Lee, Dong Han; Han, Chul Ju; Yang, Ki Young; Kim, Sang Bum

    2012-11-15

    Purpose: To identify the predictors for the development of severe gastroduodenal toxicity (GDT) in patients treated with stereotactic body radiotherapy (SBRT) using 3 fractionations for abdominopelvic malignancies. Methods and Materials: From 2001 to 2011, 202 patients with abdominopelvic malignancies were treated with curative-intent SBRT. Among these patients, we retrospectively reviewed the clinical records of 40 patients with the eligibility criteria as follows: 3 fractionations, follow-up period {>=}1 year, absence of previous radiation therapy (RT) history or combination of external-beam RT and the presence of gastroduodenum (GD) that received a dose higher than 20% of prescribed dose. The median SBRT dose was 45 Gy (range, 33-60 Gy) with 3 fractions. We analyzed the clinical and dosimetric parameters, including multiple dose-volume histogram endpoints: V{sub 20} (volume of GD that received 20 Gy), V{sub 25}, V{sub 30}, V{sub 35}, and D{sub max} (the maximum point dose). The grade of GDT was defined by the National Cancer Institute Common Toxicity Criteria version 4.0, and GDT {>=}grade 3 was defined as severe GDT. Results: The median time to the development of severe GDT was 6 months (range, 3-12 months). Severe GDT was found in 6 patients (15%). D{sub max} was the best dosimetric predictor for severe GDT. D{sub max} of 35 Gy and 38 Gy were respectively associated with a 5% and 10% probability of the development of severe GDT. A history of ulcer before SBRT was the best clinical predictor on univariate analysis (P=.0001). Conclusions: We suggest that D{sub max} is a valuable predictor of severe GDT after SBRT using 3 fractionations for abdominopelvic malignancies. A history of ulcer before SBRT should be carefully considered as a clinical predictor, especially in patients who receive a high dose to GD.

  11. Tolerance of the Spinal Cord to Stereotactic Radiosurgery: Insights From Hemangioblastomas

    SciTech Connect

    Daly, Megan E.; Choi, Clara Y.H.; Gibbs, Iris C.; Adler, John R.; Chang, Steven D.; Lieberson, Robert E.; Soltys, Scott G.

    2011-05-01

    Purpose: To evaluate spinal cord dose-volume effects, we present a retrospective review of stereotactic radiosurgery (SRS) treatments for spinal cord hemangioblastomas. Methods and Materials: From November 2001 to July 2008, 27 spinal hemangioblastomas were treated in 19 patients with SRS. Seventeen tumors received a single fraction with a median dose of 20 Gy (range, 18-30 Gy). Ten lesions were treated using 18-25 Gy in two to three sessions. Cord volumes receiving 8, 10, 12, 14, 16, 18, 20, 22, and 24 Gy and dose to 10, 100, 250, 500, 1000, and 2000 mm{sup 3} of cord were determined. Multisession treatments were converted to single-fraction biologically effective dose (SFBED). Results: Single-fraction median cord D{sub max} was 22.7 Gy (range, 17.8-30.9 Gy). Median V10 was 454 mm{sup 3} (range, 226-3543 mm{sup 3}). Median dose to 500 mm{sup 3} cord was 9.5 Gy (range, 5.3-22.5 Gy). Fractionated median SFBED{sub 3} cord D{sub max} was 14.1 Gy{sub 3} (range, 12.3-19.4 Gy{sub 3}). Potential toxicities included a Grade 2 unilateral foot drop 5 months after SRS and 2 cases of Grade 1 sensory deficits. The actuarial 3-year local tumor control estimate was 86%. Conclusions: Despite exceeding commonly cited spinal cord dose constraints, SRS for spinal hemangioblastomas is safe and effective. Consistent with animal experiments, these data support a partial-volume tolerance model for the human spinal cord. Because irradiated cord volumes were generally small, application of these data to other clinical scenarios should be made cautiously. Further prospective studies of spinal radiosurgery are needed.

  12. Adaptive Liver Stereotactic Body Radiation Therapy: Automated Daily Plan Reoptimization Prevents Dose Delivery Degradation Caused by Anatomy Deformations

    SciTech Connect

    Leinders, Suzanne M.; Breedveld, Sebastiaan; Méndez Romero, Alejandra; Schaart, Dennis; Seppenwoolde, Yvette; Heijmen, Ben J.M.

    2013-12-01

    Purpose: To investigate how dose distributions for liver stereotactic body radiation therapy (SBRT) can be improved by using automated, daily plan reoptimization to account for anatomy deformations, compared with setup corrections only. Methods and Materials: For 12 tumors, 3 strategies for dose delivery were simulated. In the first strategy, computed tomography scans made before each treatment fraction were used only for patient repositioning before dose delivery for correction of detected tumor setup errors. In adaptive second and third strategies, in addition to the isocenter shift, intensity modulated radiation therapy beam profiles were reoptimized or both intensity profiles and beam orientations were reoptimized, respectively. All optimizations were performed with a recently published algorithm for automated, multicriteria optimization of both beam profiles and beam angles. Results: In 6 of 12 cases, violations of organs at risk (ie, heart, stomach, kidney) constraints of 1 to 6 Gy in single fractions occurred in cases of tumor repositioning only. By using the adaptive strategies, these could be avoided (<1 Gy). For 1 case, this needed adaptation by slightly underdosing the planning target volume. For 2 cases with restricted tumor dose in the planning phase to avoid organ-at-risk constraint violations, fraction doses could be increased by 1 and 2 Gy because of more favorable anatomy. Daily reoptimization of both beam profiles and beam angles (third strategy) performed slightly better than reoptimization of profiles only, but the latter required only a few minutes of computation time, whereas full reoptimization took several hours. Conclusions: This simulation study demonstrated that replanning based on daily acquired computed tomography scans can improve liver stereotactic body radiation therapy dose delivery.

  13. 10 CFR 35.645 - Periodic spot-checks for gamma stereotactic radiosurgery units.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Periodic spot-checks for gamma stereotactic radiosurgery... § 35.645 Periodic spot-checks for gamma stereotactic radiosurgery units. (a) A licensee authorized to... minimum— (1) Assure proper operation of— (i) Treatment table retraction mechanism, using backup...

  14. 10 CFR 35.645 - Periodic spot-checks for gamma stereotactic radiosurgery units.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Periodic spot-checks for gamma stereotactic radiosurgery units. 35.645 Section 35.645 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy Units, and Gamma Stereotactic Radiosurgery...

  15. 10 CFR 35.2632 - Records of teletherapy, remote afterloader, and gamma stereotactic radiosurgery full calibrations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of teletherapy, remote afterloader, and gamma stereotactic radiosurgery full calibrations. 35.2632 Section 35.2632 Energy NUCLEAR REGULATORY COMMISSION... stereotactic radiosurgery unit(s), the source(s), and the instruments used to calibrate the unit(s); (3)...

  16. 10 CFR 35.2632 - Records of teletherapy, remote afterloader, and gamma stereotactic radiosurgery full calibrations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... stereotactic radiosurgery full calibrations. (a) A licensee shall maintain a record of the teletherapy unit... 10 Energy 1 2014-01-01 2014-01-01 false Records of teletherapy, remote afterloader, and gamma stereotactic radiosurgery full calibrations. 35.2632 Section 35.2632 Energy NUCLEAR REGULATORY...

  17. 10 CFR 35.2632 - Records of teletherapy, remote afterloader, and gamma stereotactic radiosurgery full calibrations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... stereotactic radiosurgery full calibrations. (a) A licensee shall maintain a record of the teletherapy unit... 10 Energy 1 2011-01-01 2011-01-01 false Records of teletherapy, remote afterloader, and gamma stereotactic radiosurgery full calibrations. 35.2632 Section 35.2632 Energy NUCLEAR REGULATORY...

  18. 10 CFR 35.2632 - Records of teletherapy, remote afterloader, and gamma stereotactic radiosurgery full calibrations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... stereotactic radiosurgery full calibrations. (a) A licensee shall maintain a record of the teletherapy unit... 10 Energy 1 2012-01-01 2012-01-01 false Records of teletherapy, remote afterloader, and gamma stereotactic radiosurgery full calibrations. 35.2632 Section 35.2632 Energy NUCLEAR REGULATORY...

  19. 10 CFR 35.2632 - Records of teletherapy, remote afterloader, and gamma stereotactic radiosurgery full calibrations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... stereotactic radiosurgery full calibrations. (a) A licensee shall maintain a record of the teletherapy unit... 10 Energy 1 2013-01-01 2013-01-01 false Records of teletherapy, remote afterloader, and gamma stereotactic radiosurgery full calibrations. 35.2632 Section 35.2632 Energy NUCLEAR REGULATORY...

  20. Dosimetric verification of stereotactic radiosurgery/stereotactic radiotherapy dose distributions using Gafchromic EBT3

    SciTech Connect

    Cusumano, Davide; Fumagalli, Maria L.; Marchetti, Marcello; Fariselli, Laura; De Martin, Elena

    2015-10-01

    Aim of this study is to examine the feasibility of using the new Gafchromic EBT3 film in a high-dose stereotactic radiosurgery and radiotherapy quality assurance procedure. Owing to the reduced dimensions of the involved lesions, the feasibility of scanning plan verification films on the scanner plate area with the best uniformity rather than using a correction mask was evaluated. For this purpose, signal values dispersion and reproducibility of film scans were investigated. Uniformity was then quantified in the selected area and was found to be within 1.5% for doses up to 8 Gy. A high-dose threshold level for analyses using this procedure was established evaluating the sensitivity of the irradiated films. Sensitivity was found to be of the order of centiGray for doses up to 6.2 Gy and decreasing for higher doses. The obtained results were used to implement a procedure comparing dose distributions delivered with a CyberKnife system to planned ones. The procedure was validated through single beam irradiation on a Gafchromic film. The agreement between dose distributions was then evaluated for 13 patients (brain lesions, 5 Gy/die prescription isodose ~80%) using gamma analysis. Results obtained using Gamma test criteria of 5%/1 mm show a pass rate of 94.3%. Gamma frequency parameters calculation for EBT3 films showed to strongly depend on subtraction of unexposed film pixel values from irradiated ones. In the framework of the described dosimetric procedure, EBT3 films proved to be effective in the verification of high doses delivered to lesions with complex shapes and adjacent to organs at risk.

  1. Understanding Multiplication of Fractions.

    ERIC Educational Resources Information Center

    Sweetland, Robert D.

    1984-01-01

    Discussed the use of Cuisenaire rods in teaching the multiplication of fractions. Considers whole number times proper fraction, proper fraction multiplied by proper fraction, mixed number times proper fraction, and mixed fraction multiplied by mixed fractions. (JN)

  2. Magnetic resonance imaging, computed tomography, and 68Ga-DOTATOC positron emission tomography for imaging skull base meningiomas with infracranial extension treated with stereotactic radiotherapy - a case series

    PubMed Central

    2012-01-01

    Introduction Magnetic resonance imaging (MRI) and computed tomography (CT) with 68Ga-DOTATOC positron emission tomography (68Ga-DOTATOC-PET) were compared retrospectively for their ability to delineate infracranial extension of skull base (SB) meningiomas treated with fractionated stereotactic radiotherapy. Methods Fifty patients with 56 meningiomas of the SB underwent MRI, CT, and 68Ga-DOTATOC PET/CT prior to fractionated stereotactic radiotherapy. The study group consisted of 16 patients who had infracranial meningioma extension, visible on MRI ± CT (MRI/CT) or PET, and were evaluated further. The respective findings were reviewed independently, analyzed with respect to correlations, and compared with each other. Results Within the study group, SB transgression was associated with bony changes visible by CT in 14 patients (81%). Tumorous changes of the foramen ovale and rotundum were evident in 13 and 8 cases, respectively, which were accompanied by skeletal muscular invasion in 8 lesions. We analysed six designated anatomical sites of the SB in each of the 16 patients. Of the 96 sites, 42 had infiltration that was delineable by MRI/CT and PET in 35 cases and by PET only in 7 cases. The mean infracranial volume that was delineable in PET was 10.1 ± 10.6 cm3, which was somewhat larger than the volume detectable in MRI/CT (8.4 ± 7.9 cm3). Conclusions 68Ga-DOTATOC-PET allows detection and assessment of the extent of infracranial meningioma invasion. This method seems to be useful for planning fractionated stereotactic radiation when used in addition to conventional imaging modalities that are often inconclusive in the SB region. PMID:22217329

  3. Novel approach to lung stereotactic body radiation therapy plan evaluation and delivery

    NASA Astrophysics Data System (ADS)

    Jurkovic, Ines-Ana

    Stereotactic body radiation therapy is currently being used as an efficient treatment for Stage I/II medically inoperable and surgically unrespectable non small cell and metastatic lung cancer. Hypofractional dose and dose escalation used in stereotactic body radiation therapy have the potential of increasing the likelihood of the tumor control and the long term progression free survival. Currently available commercial treatment planning systems are capable of calculating accurate dose distributions for static case, where the tumor and surrounding healthy tissues are not moving during the dose delivery. However, respiratory induced organ motion can result in significant movement of the lesion leading to the discrepancies between the dose delivered and the dose planned. The precision and conformity of the stereotactic body radiation therapy makes it very susceptible to motion, i.e. patient respiration can lead to significant dose delivery errors. Conventional stereotactic body radiation therapy treatment plans use free breathing three-dimensional computed tomography images where margins are added to delineated gross tumor volume to create planning tumor volume and avoid geometrical misses of the target. The specific hypothesis of the study is that the true four-dimensional delivery of the four-dimensional plans will allow for more accurate radiation therapy treatment and critical organ sparing along with radiobiological evaluation of the dose distributions. The specific aims are designed to provide in depth understanding of the radiation therapy treatments and influence of the four-dimensional planning and delivery, heterogeneity corrections and various radiobiological factors on the outcome. The primary focus of the Specific Aim 1 was the evaluation of the tumor volume based on the four-dimensional computed tomography scan data through its motion, volume and computed tomography number. The results indicated that tumor motion parameters will exceed the typical

  4. Stereotactic Radiotherapy for Cervical Spinal Intramedullary Metastasis and Multiple Brain Metastases: A Case Report.

    PubMed

    Mori, Yoshimasa; Kawamura, Toshiki; Ohshima, Yukihiko; Takeuchi, Arisa; Mori, Toshie; Ishiguchi, Tuneo

    2016-04-27

    A case of cervical (C) spinal intramedullary metastasis and multiple small brain metastases from papillary thyroid carcinoma was presented. Spinal metastasis caused posterior neck and left shoulder pain, dysesthesia in both legs, and motor weakness in both legs and left arm, though the brain metastases were asymptomatic. Both the spinal and brain metastases were successfully treated by frameless stereotactic radiotherapy (SRT)/stereotactic radiosurgery (SRS). The patient's symptoms were almost entirely relieved within two months. A 76-year-old woman was diagnosed as having a thyroid tumor and lung metastasis by roentgenography and computed tomography. Biopsy of the thyroid tumor extending into the mediastinum revealed papillary thyroid carcinoma. She underwent surgical resection of thyroid with dissection of the mediastinum lymph node area. Internal oral radioisotope therapy was not effective for the multiple small lung metastases. She did well for 15 months, but later developed posterior neck and left shoulder pain and dysesthesia in the right leg and then dysesthesia and motor weakness in both legs. Then she experienced weakness in the left upper extremity. Magnetic resonance imaging (MRI) disclosed a small cervical spinal intramedullary mass lesion at the level of C6 and C7 on the left side as well as nine small brain lesions. The cervical spinal intramedullary metastatic tumor was treated by volumetric modulated arc radiotherapy (VMAT) SRT and the nine small brain metastatic tumors were treated by dynamic conformal arc (DCA) SRS uneventfully. A total dose of 39 Gy (100% dose) was delivered in 13 fractions for the spinal lesion (prescription, D95=95% dose; maximum dose=46.3 Gy). Single fraction SRS of 22 Gy (prescription, D95=100% dose) was performed for each of the nine small brain tumors. The spinal tumor was decreased in size on follow-up MRI two months after SRT. Three of the nine brain lesions had disappeared and six were decreased in size on

  5. Stereotactic Radiotherapy for Cervical Spinal Intramedullary Metastasis and Multiple Brain Metastases: A Case Report

    PubMed Central

    Kawamura, Toshiki; Ohshima, Yukihiko; Takeuchi, Arisa; Mori, Toshie; Ishiguchi, Tuneo

    2016-01-01

    A case of cervical (C) spinal intramedullary metastasis and multiple small brain metastases from papillary thyroid carcinoma was presented. Spinal metastasis caused posterior neck and left shoulder pain, dysesthesia in both legs, and motor weakness in both legs and left arm, though the brain metastases were asymptomatic. Both the spinal and brain metastases were successfully treated by frameless stereotactic radiotherapy (SRT)/stereotactic radiosurgery (SRS). The patient's symptoms were almost entirely relieved within two months. A 76-year-old woman was diagnosed as having a thyroid tumor and lung metastasis by roentgenography and computed tomography. Biopsy of the thyroid tumor extending into the mediastinum revealed papillary thyroid carcinoma. She underwent surgical resection of thyroid with dissection of the mediastinum lymph node area. Internal oral radioisotope therapy was not effective for the multiple small lung metastases. She did well for 15 months, but later developed posterior neck and left shoulder pain and dysesthesia in the right leg and then dysesthesia and motor weakness in both legs. Then she experienced weakness in the left upper extremity. Magnetic resonance imaging (MRI) disclosed a small cervical spinal intramedullary mass lesion at the level of C6 and C7 on the left side as well as nine small brain lesions. The cervical spinal intramedullary metastatic tumor was treated by volumetric modulated arc radiotherapy (VMAT) SRT and the nine small brain metastatic tumors were treated by dynamic conformal arc (DCA) SRS uneventfully. A total dose of 39 Gy (100% dose) was delivered in 13 fractions for the spinal lesion (prescription, D95=95% dose; maximum dose=46.3 Gy). Single fraction SRS of 22 Gy (prescription, D95=100% dose) was performed for each of the nine small brain tumors. The spinal tumor was decreased in size on follow-up MRI two months after SRT. Three of the nine brain lesions had disappeared and six were decreased in size on

  6. Mystery Fractions

    ERIC Educational Resources Information Center

    Bhattacharyya, Sonalee; Namakshi, Nama; Zunker, Christina; Warshauer, Hiroko K.; Warshauer, Max

    2016-01-01

    Making math more engaging for students is a challenge that every teacher faces on a daily basis. These authors write that they are constantly searching for rich problem-solving tasks that cover the necessary content, develop critical-thinking skills, and engage student interest. The Mystery Fraction activity provided here focuses on a key number…

  7. Pitch Fractionation.

    DTIC Science & Technology

    1981-12-15

    13 3. Solvent Fractionation Experiments .................................... 15 4. Fourier Transform Infrared Spectra for A240 Petrolem Pitch AG 12...34 and Mesophase Pitch AG 164B ............................... 21 5. Fourier Transform Infrared Spectra ................................... 23 6...compared by Fourier transform infrared (FTIR) analysis using a Digilab Model FTS 14 spectrophotometer (Rockwell International, Anaheim, California

  8. Alisertib and Fractionated Stereotactic Radiosurgery in Treating Patients With Recurrent High Grade Gliomas

    ClinicalTrials.gov

    2016-10-19

    Adult Anaplastic Astrocytoma; Adult Anaplastic Ependymoma; Adult Anaplastic Oligodendroglioma; Adult Brain Stem Glioma; Adult Diffuse Astrocytoma; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Mixed Glioma; Adult Oligodendroglioma; Adult Pilocytic Astrocytoma; Adult Pineal Gland Astrocytoma; Adult Subependymal Giant Cell Astrocytoma; Recurrent Adult Brain Tumor

  9. let-7 Overexpression Leads to an Increased Fraction of Cells in G2/M, Direct Down-regulation of Cdc34, and Stabilization of Wee1 Kinase in Primary Fibroblasts*S⃞

    PubMed Central

    Legesse-Miller, Aster; Elemento, Olivier; Pfau, Sarah J.; Forman, Joshua J.; Tavazoie, Saeed; Coller, Hilary A.

    2009-01-01

    microRNAs play a critically important role in a wide array of biological processes including those implicated in cancer, neuro-degenerative and metabolic disorders, and viral infection. Although we have begun to understand microRNA biogenesis and function, experimental demonstration of their functional effects and the molecular mechanisms by which they function remains a challenge. Members of the let-7/miR-98 family play a critical role in cell cycle control with respect to differentiation and tumorigenesis. In this study, we show that exogenous addition of pre-let-7 in primary human fibroblasts results in a decrease in cell number and an increased fraction of cells in the G2/M cell cycle phase. Combining microarray techniques with DNA sequence analysis to identify potential let-7 targets, we discovered 838 genes with a let-7 binding site in their 3′-untranslated region that were down-regulated upon overexpression of let-7b. Among these genes is cdc34, the ubiquitin-conjugating enzyme of the Skp1/cullin/F-box (SCF) complex. Cdc34 protein levels are strongly down-regulated by let-7 overexpression. Reporter assays demonstrated direct regulation of the cdc34 3′-untranslated region by let-7. We hypothesized that low Cdc34 levels would result in decreased SCF activity, stabilization of the SCF target Wee1, and G2/M accumulation. Consistent with this hypothesis, small interfering RNA-mediated down-regulation of Wee1 reversed the G2/M phenotype induced by let-7 overexpression. We conclude that Cdc34 is a functional target of let-7 and that let-7 induces down-regulation of Cdc34, stabilization of the Wee1 kinase, and an increased fraction of cells in G2/M in primary fibroblasts. PMID:19126550

  10. Common Prairie feeds with different soluble and insoluble fractions used for CPM diet formulation in dairy cattle: Impact of carbohydrate-protein matrix structure on protein and other primary nutrient digestion

    NASA Astrophysics Data System (ADS)

    Peng, Quanhui; Wang, Zhisheng; Zhang, Xuewei; Yu, Peiqiang

    2014-03-01

    An experiment was conducted to investigate the relationship of carbohydrates molecular spectral characteristics to rumen degradability of primary nutrients in Prairie feeds in dairy cattle. In total, 12 different types of feeds were selected, each type of feed was from three different source with total 37 samples. Six types of them were energy-sourced feeds and the others were protein-sourced feeds. The carbohydrates molecular spectral intensity of various functional groups were collected using Fourier transform infrared attenuated total reflectance (ATR-FT/IR) spectroscopy. In the in situ study, the results showed that the rumen digestibility and digestible fractions of primary nutrients (DM, OM, NCP, and CP) were significantly different (P < 0.05) among the feeds. The spectral bands features were significantly different (P < 0.05) among the feeds. Spectral intensities of A_Cell, H_1415 and H_1370 were weakly positively correlated with in situ rumen digestibility and digestible fractions of DM, OM and NCP. Spectral intensities of H_1150, H_1015, A_1, and A_3 were weakly negatively associated with in situ rumen degradation of CP. Spectral intensities of A_1240 and H_1240, mainly associated with cellulosic compounds, were correlated with rumen CP degradation. The multiple regression analysis demonstrated that the spectral intensities of A_3 and H_1415 played the most important role and could be used as a potential tool to predict rumen protein degradation of feeds in dairy cattle. In conclusion, this study showed that the carbohydrates as a whole have an effect on protein rumen degradation, rather than cellulose alone, indicating carbohydrate-protein matrix structure impact protein utilization in dairy cattle. The non-invasive molecular spectral technique (ATR-FT/IR) could be used as a rapid potential tool to predict rumen protein degradation of feedstuffs by using molecular spectral bands intensities in carbohydrate fingerprint region.

  11. Common Prairie feeds with different soluble and insoluble fractions used for CPM diet formulation in dairy cattle: impact of carbohydrate-protein matrix structure on protein and other primary nutrient digestion.

    PubMed

    Peng, Quanhui; Wang, Zhisheng; Zhang, Xuewei; Yu, Peiqiang

    2014-01-01

    An experiment was conducted to investigate the relationship of carbohydrates molecular spectral characteristics to rumen degradability of primary nutrients in Prairie feeds in dairy cattle. In total, 12 different types of feeds were selected, each type of feed was from three different source with total 37 samples. Six types of them were energy-sourced feeds and the others were protein-sourced feeds. The carbohydrates molecular spectral intensity of various functional groups were collected using Fourier transform infrared attenuated total reflectance (ATR-FT/IR) spectroscopy. In the in situ study, the results showed that the rumen digestibility and digestible fractions of primary nutrients (DM, OM, NCP, and CP) were significantly different (P<0.05) among the feeds. The spectral bands features were significantly different (P<0.05) among the feeds. Spectral intensities of A_Cell, H_1415 and H_1370 were weakly positively correlated with in situ rumen digestibility and digestible fractions of DM, OM and NCP. Spectral intensities of H_1150, H_1015, A_1, and A_3 were weakly negatively associated with in situ rumen degradation of CP. Spectral intensities of A_1240 and H_1240, mainly associated with cellulosic compounds, were correlated with rumen CP degradation. The multiple regression analysis demonstrated that the spectral intensities of A_3 and H_1415 played the most important role and could be used as a potential tool to predict rumen protein degradation of feeds in dairy cattle. In conclusion, this study showed that the carbohydrates as a whole have an effect on protein rumen degradation, rather than cellulose alone, indicating carbohydrate-protein matrix structure impact protein utilization in dairy cattle. The non-invasive molecular spectral technique (ATR-FT/IR) could be used as a rapid potential tool to predict rumen protein degradation of feedstuffs by using molecular spectral bands intensities in carbohydrate fingerprint region.

  12. Effect of CyberKnife stereotactic body radiation therapy for hepatocellular carcinoma on hepatic toxicity

    PubMed Central

    Liang, Ping; Huang, Cheng; Liang, Shi-Xiong; Li, Ye-Fei; Huang, Shang-Xiao; Lian, Zu-Ping; Liu, Jian-Min; Tang, Yang; Lu, Hai-Jie

    2016-01-01

    Objective To evaluate the safety of CyberKnife stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC) patients and identify the treatment-related risk factors of hepatic toxicity. Materials and methods One hundred and four HCC patients treated with CyberKnife SBRT were included in this study between August 2009 and December 2012. The average dose of prescribed radiation was 42.81±4.78 Gy (28–55 Gy) with the average fraction size of 8–16 Gy to the planning target volume. The average fractions were 3.31±0.81 (2–6 fractions). Response rates were determined, and the Child–Pugh (CP) score and class following CyberKnife SBRT were obtained to evaluate hepatic toxicity. Results Seventeen patients experienced progression in CP class and 24 patients experienced CTCAE V. 4.0 grade 2–3 hepatic toxicity during the five-month follow-up period, while no patient experienced grade 4 liver toxicity. Multivariate analysis indicated that only V25 was an independent factor in grade 2–3 hepatic toxicity (P=0.029, <0.05). Radiation-induced hepatic toxicity (RIHT), defined as an increase of at least two points within three months following CyberKnife SBRT, occurred in 13 of the 104 patients (13/104, 12.5%), and only the normal liver tissue was found to be associated with RIHT (P=0.008, <0.05). Conclusion CyberKnife SBRT is a feasible and safe treatment for HCC with regard to hepatic toxicity, while V25 and normal liver volume may be an independent factor of grade 2–3 hepatic toxicity and RIHT, respectively. PMID:27920555

  13. Review of long-term results of stereotactic psychosurgery.

    PubMed

    Kim, Moon-Chan; Lee, Tae-Kyu; Choi, Chang-Rak

    2002-09-01

    Stereotactic psychosurgery is an effective method for treating some medically intractable psychiatric illnesses. However, it is unfamiliar and the long-term clinical results have not been reported in Asia. The long-term results of psychosurgery are evaluated and the neuroanatomical basis is discussed. Twenty-one patients underwent stereotactic psychosurgery for medically intractable psychiatric illnesses since 1993. All were referred from psychiatrists for these disorders. Two patients showed aggressive behavior, 12 had obsessive-compulsive disorder (OCD), and seven had depression with anxiety disorders. Bilateral amygdalotomy and subcaudate tractotomy were performed for aggressive behavior, limbic leucotomy was performed for OCD, and subcaudate tractotomy with or without cingulotomy was performed for depression with anxiety. OCD was evaluated with the Yale-Brown Obsessive Compulsive Scale (YBOCS), the visual analogue scale, the Clinical Global Impression Scale, and the Overt Aggression Scale (OAS). The Mini-Mental State Examination and the Wechsler Adult Intelligence Scale-Revised were used for the evaluation of aggressive behavior. The 17-item Hamilton Depression Rating Scale (HAMD) was used for evaluation of depression. Ventriculography was used in the first seven patients and magnetic resonance imaging-guided stereotaxy was used in the recent 14 cases for localization of the target. The lesions were made with a radiofrequency lesion generator. OAS scores in the two patients with aggressive behavior during follow up declined from 8 to 2 with clinical improvement. All 12 patients with OCD returned to their previous life and showed the mean YBOCS scores decreased from 34 to 3. Ten patients with OCD could be followed up (mean 45 months). All patients returned to their previous social life. In seven patients with depression with anxiety, HAMD scores declined from 28.5 to 16.5. There was no operative mortality and no significant morbidity except for one case of mild

  14. Isocentric stereotactic three-dimensional digitizer for neurosurgery.

    PubMed

    Takizawa, T

    1993-01-01

    A new system has been developed, comprising a frameless isocentric stereotactic mechanism and a three-dimensional (3-D) digitizer for intraoperative spatial monitoring. The 3-D digitizer's multiarticulated arm has three joints related to Cartesian coordinates, two quadrant arcs forming an isocenter system, a microdrive, and a probe holder. The frameless isocentric mechanism is useful for open stereotaxy. Routine CT- or MRI-guided stereotactic surgery is also possible, due to the high level of accuracy of the system. Before surgery, CT and/or MR images are acquired after placing on the scalp three or four external markers. For surgical procedures which require high accuracy, Laitinen's noninvasive CT or MRI localizing markers are used. CT or MR images are entered into a computer using an image scanner, and are stored on a floppy disk. After the patient's head is fixed to the operating table using a Mayfield clamp, the 3-D digitizer is used to read the spatial points and external markers on the scalp or the reference points of Laitinen's localizing markers. During the procedure, the coordinates on the patient's head are automatically entered into the computer and matched with those of the 3-D digitizer and CT/MR images on the CRT display. This system has been used in 22 cases of open craniotomy and 33 cases of burr hole surgery, both carried out using the stereotactic function and the 3-D spatial monitoring function in parallel. Errors in mechanical accuracy of the 3-D digitizer were less than 0.8 mm, and the maximum error during operation was presumed not to exceed 2 mm.

  15. The treatment of recurrent brain metastases with stereotactic radiosurgery.

    PubMed

    Loeffler, J S; Kooy, H M; Wen, P Y; Fine, H A; Cheng, C W; Mannarino, E G; Tsai, J S; Alexander, E

    1990-04-01

    Between May 1986 and August 1989, we treated 18 patients with 21 recurrent or persistent brain metastases with stereotactic radiosurgery using a modified linear accelerator. To be eligible for radiosurgery, patients had to have a performance status of greater than or equal to 70% and have no evidence of (or stable) systemic disease. All but one patient had received prior radiotherapy, and were treated with stereotactic radiosurgery at the time of recurrence. Polar lesions were treated only if the patient had undergone and failed previous complete surgical resection (10 patients). Single doses of radiation (900 to 2,500 cGy) were delivered to limited volumes (less than 27 cm3) using a modified 6MV linear accelerator. The most common histology of the metastatic lesion was carcinoma of the lung (seven patients), followed by carcinoma of the breast (four patients), and melanoma (four patients). With median follow-up of 9 months (range, 1 to 39), all tumors have been controlled in the radiosurgery field. Two patients failed in the immediate margin of the treated volume and were subsequently treated with surgery and implantation of 125I to control the disease. Radiographic response was dramatic and rapid in the patients with adenocarcinoma, while slight reduction and stabilization occurred in those patients with melanoma, renal cell carcinoma, and sarcoma. The majority of patients improved neurologically following treatment, and were able to be withdrawn from corticosteroid therapy. Complications were limited and transient in nature and no cases of symptomatic radiation necrosis occurred in any patient despite previous exposure to radiotherapy. Stereotactic radiosurgery is an effective and relatively safe treatment for recurrent solitary metastases and is an appealing technique for the initial management of deep-seated lesions as a boost to whole brain radiotherapy.

  16. Phase I dose-escalation study of helical intensity-modulated radiotherapy-based stereotactic body radiotherapy for hepatocellular carcinoma

    PubMed Central

    Kim, Jun Won; Seong, Jinsil; Lee, Ik Jae; Woo, Joong Yeol; Han, Kwang-Hyub

    2016-01-01

    Background Phase I trial was conducted to determine feasibility and toxicity of helical intensity-modulated radiotherapy (IMRT)-based stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC). Results Eighteen patients (22 lesions) were enrolled. With no DLT at 52 Gy (13 Gy/fraction), protocol was amended for further escalation to 60 Gy (15 Gy/fraction). Radiologic complete response rate was 88.9%. Two outfield intrahepatic, 2 distant, 4 concurrent local and outfield, and 1 concurrent local, outfield and distant failures (no local failure at dose levels 3–4) occurred. The worst toxicity was grade 3 hematologic in five patients, with no gastrointestinal toxicity > grade 1. At median follow-up of 28 months for living patients, 2-year local control, progression-free (PFS), and overall survival rates were 71.3%, 49.4% and 69.3%, respectively. Multi-segmental recurrences prior to SBRT was independent prognostic factor for PFS (p = 0.033). Materials and Methods Eligible patients had Child-Pugh's class A or B, unresectable HCC, ≤ 3 lesions, and cumulative tumor diameter ≤ 6 cm. Starting at 36 Gy in four fractions, dose was escalated with 2 Gy/fraction per dose-level. CTCAE v 3.0 ≥ grade 3 gastrointestinal toxicity and radiation induced liver disease defined dose-limiting toxicity (DLT). Conclusions Helical IMRT-based SBRT was tolerable and showed encouraging results. Confirmatory phase II trial is underway. PMID:27213593

  17. Novalis Stereotactic Radiosurgery for Spinal Dural Arteriovenous Fistula.

    PubMed

    Sung, Kyoung-Su; Song, Young-Jin; Kim, Ki-Uk

    2016-07-01

    The spinal dural arteriovenous fistula (SDAVF) is rare, presenting with progressive, insidious symptoms, and inducing spinal cord ischemia and myelopathy, resulting in severe neurological deficits. If physicians have accurate and enough information about vascular anatomy and hemodynamics, they achieve the good results though the surgery or endovascular embolization. However, when selective spinal angiography is unsuccessful due to neurological deficits, surgery and endovascular embolization might be failed because of inadequate information. We describe a patient with a history of vasospasm during spinal angiography, who was successfully treated by spinal stereotactic radiosurgery using Novalis system.

  18. Novalis Stereotactic Radiosurgery for Spinal Dural Arteriovenous Fistula

    PubMed Central

    Sung, Kyoung-Su; Song, Young-Jin

    2016-01-01

    The spinal dural arteriovenous fistula (SDAVF) is rare, presenting with progressive, insidious symptoms, and inducing spinal cord ischemia and myelopathy, resulting in severe neurological deficits. If physicians have accurate and enough information about vascular anatomy and hemodynamics, they achieve the good results though the surgery or endovascular embolization. However, when selective spinal angiography is unsuccessful due to neurological deficits, surgery and endovascular embolization might be failed because of inadequate information. We describe a patient with a history of vasospasm during spinal angiography, who was successfully treated by spinal stereotactic radiosurgery using Novalis system. PMID:27446527

  19. Development of a new microsurgical robot for stereotactic neurosurgery.

    PubMed

    Koyama, H; Uchida, T; Funakubo, H; Takakura, K; Fankhauser, H

    1990-01-01

    The robot technology was introduced into a new stereotactic neurosurgery system for applications to biopsy, blind surgery, and functional neurosurgery. The authors have developed a newly designed prototype microsurgical robot, designed to allow a biopsy needle to reach the target such as a cerebral tumor within a brain automatically on the basis of the X, Y, and Z coordinates obtained by CT scanner. This robot is so small that it can be driven in a CT scanner gantry. It consists mainly of the link mechanism and the insertion mechanism. We constructed the link mechanism and investigated its working space.

  20. Technique for Robotic Stereotactic Irradiation of Choroidal Melanoma.

    PubMed

    Béliveau-Nadeau, Dominic; Callejo, Sonia; Roberge, David

    2016-04-21

    Radiotherapy has a long history in the organ-sparing management of choroidal melanoma. Joining plaque radiotherapy and proton irradiation, stereotactic robotic photon irradiation is a new tool in the radiation oncologist's armamentarium for ocular tumors. The non-coplanar fields with steep dose gradients are well suited to spare uninvolved retina, anterior chamber, and the optic nerve. In our practice, it is the preferred treatment for melanomas that are non-amenable to standard plaque brachytherapy. Since late 2010, we have treated more than 40 patients with our robotic linear accelerator. This case-based technical note outlines the technique used at the University of Montreal, Montreal, Canada.

  1. Technique for Robotic Stereotactic Irradiation of Choroidal Melanoma

    PubMed Central

    Béliveau-Nadeau, Dominic; Callejo, Sonia

    2016-01-01

    Radiotherapy has a long history in the organ-sparing management of choroidal melanoma. Joining plaque radiotherapy and proton irradiation, stereotactic robotic photon irradiation is a new tool in the radiation oncologist’s armamentarium for ocular tumors. The non-coplanar fields with steep dose gradients are well suited to spare uninvolved retina, anterior chamber, and the optic nerve. In our practice, it is the preferred treatment for melanomas that are non-amenable to standard plaque brachytherapy. Since late 2010, we have treated more than 40 patients with our robotic linear accelerator. This case-based technical note outlines the technique used at the University of Montreal, Montreal, Canada. PMID:27226942

  2. Salvage Stereotactic Body Radiotherapy (SBRT) Following In-Field Failure of Initial SBRT for Spinal Metastases

    SciTech Connect

    Thibault, Isabelle; Campbell, Mikki; Tseng, Chia-Lin; Atenafu, Eshetu G.; Letourneau, Daniel; Yu, Eugene; Cho, B.C. John; Lee, Young K.; Fehlings, Michael G.; Sahgal, Arjun

    2015-10-01

    Purpose: We report our experience in salvaging spinal metastases initially irradiated with stereotactic body radiation therapy (SBRT), who subsequently progressed with imaging-confirmed local tumor progression, and were re-irradiated with a salvage second SBRT course to the same level. Methods and Materials: From a prospective database, 56 metastatic spinal segments in 40 patients were identified as having been irradiated with a salvage second SBRT course to the same level. In addition, 24 of 56 (42.9%) segments had initially been irradiated with conventional external beam radiation therapy before the first course of SBRT. Local control (LC) was defined as no progression on magnetic resonance imaging at the treated segment, and calculated according to the competing risk model. Overall survival (OS) was evaluated for each patient treated by use of the Kaplan-Meier method. Results: The median salvage second SBRT total dose and number of fractions was 30 Gy in 4 fractions (range, 20-35 Gy in 2-5 fractions), and for the first course of SBRT was 24 Gy in 2 fractions (range, 20-35 Gy in 1-5 fractions). The median follow-up time after salvage second SBRT was 6.8 months (range, 0.9-39 months), the median OS was 10.0 months, and the 1-year OS rate was 48%. A longer time interval between the first and second SBRT courses predicted for better OS (P=.02). The crude LC was 77% (43/56), the 1-year LC rate was 81%, and the median time to local failure was 3.0 months (range, 2.7-16.7 months). Of the 13 local failures, 85% (11/13) and 46% (6/13) showed progression within the epidural space and paraspinal soft tissues, respectively. Absence of baseline paraspinal disease predicted for better LC (P<.01). No radiation-induced vertebral compression fractures or cases of myelopathy were observed. Conclusion: A second course of spine SBRT, most often with 30 Gy in 4 fractions, for spinal metastases that failed initial SBRT is a feasible and efficacious salvage treatment option.

  3. SU-E-T-624: Quantitative Evaluation of 2D Versus 3D Dosimetry for Stereotactic Volumetric Modulated Arc Delivery Using COMPASS

    SciTech Connect

    Vikraman, S; Karrthick, K; Rajesh, T; Sambasivaselli, R; Senniandanvar, V; Kataria, T; Manigandan, D; Karthikeyan, N; Muthukumaran, M

    2014-06-15

    Purpose: The purpose of this study was to evaluate quantitatively 2D versus 3D dosimetry for stereotactic volumetric modulated arc delivery using COMPASS with 2D array. Methods: Twenty-five patients CT images and RT structures of different sites like brain, head and neck, thorax, abdomen and spine were taken from Multiplan planning system for this study. All these patients underwent radical stereotactic treatment in Cyberknife. For each patient, linac based VMAT stereotactic plans were generated in Monaco TPS v 3.1 using Elekta Beam Modulator MLC. Dose prescription was in the range of 5-20Gy/fraction.TPS calculated VMAT plan delivery accuracy was quantitatively evaluated with COMPASS measured dose and calculated dose based on DVH metrics. In order to ascertain the potential of COMPASS 3D dosimetry for stereotactic plan delivery, 2D fluence verification was performed with MatriXX using Multicube. Results: For each site, D{sub 9} {sub 5} was achieved with 100% of prescription dose with maximum 0.05SD. Conformity index (CI) was observed closer to 1.15 in all cases. Maximum deviation of 2.62 % was observed for D{sub 9} {sub 5} when compared TPS versus COMPASS measured. Considerable deviations were observed in head and neck cases compare to other sites. The maximum mean and standard deviation for D{sub 9} {sub 5}, average target dose and average gamma were -0.78±1.72, -1.10±1.373 and 0.39±0.086 respectively. Numbers of pixels passing 2D fluence verification were observed as a mean of 99.36% ±0.455 SD with 3% dose difference and 3mm DTA. For critical organs in head and neck cases, significant dose differences were observed in 3D dosimetry while the target doses were matched well within limit in both 2D and 3D dosimetry. Conclusion: The quantitative evaluations of 2D versus 3D dosimetry for stereotactic volumetric modulated plans showed the potential of highlighting the delivery errors. This study reveals that COMPASS 3D dosimetry is an effective tool for patient

  4. SU-E-J-240: The Impact On Clinical Dose-Distributions When Using MR-Images Registered with Stereotactic CT-Images in Gamma Knife Radiosurgery

    SciTech Connect

    Benmakhlouf, H; Kraepelien, T; Forander, P; Wangerid, T

    2014-06-01

    Purpose: Most Gamma knife treatments are based solely on MR-images. However, for fractionated treatments and to implement TPS dose calculations that require electron densities, CT image data is essential. The purpose of this work is to assess the dosimetric effects of using MR-images registered with stereotactic CT-images in Gamma knife treatments. Methods: Twelve patients treated for vestibular schwannoma with Gamma Knife Perfexion (Elekta Instruments, Sweden) were selected for this study. The prescribed doses (12 Gy to periphery) were delivered based on the conventional approach of using stereotactic MR-images only. These plans were imported into stereotactic CT-images (by registering MR-images with stereotactic CT-images using the Leksell gamma plan registration software). The dose plans, for each patient, are identical in both cases except for potential rotations and translations resulting from the registration. The impact of the registrations was assessed by an algorithm written in Matlab. The algorithm compares the dose-distributions voxel-by-voxel between the two plans, calculates the full dose coverage of the target (treated in the conventional approach) achieved by the CT-based plan, and calculates the minimum dose delivered to the target (treated in the conventional approach) achieved by the CT-based plan. Results: The mean dose difference between the plans was 0.2 Gy to 0.4 Gy (max 4.5 Gy) whereas between 89% and 97% of the target (treated in the conventional approach) received the prescribed dose, by the CT-plan. The minimum dose to the target (treated in the conventional approach) given by the CT-based plan was between 7.9 Gy and 10.7 Gy (compared to 12 Gy in the conventional treatment). Conclusion: The impact of using MR-images registered with stereotactic CT-images has successfully been compared to conventionally delivered dose plans showing significant differences between the two. Although CTimages have been implemented clinically; the effect of the

  5. Fraction Reduction through Continued Fractions

    ERIC Educational Resources Information Center

    Carley, Holly

    2011-01-01

    This article presents a method of reducing fractions without factoring. The ideas presented may be useful as a project for motivated students in an undergraduate number theory course. The discussion is related to the Euclidean Algorithm and its variations may lead to projects or early examples involving efficiency of an algorithm.

  6. Isotope fractionation

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    A rash of new controversy has emerged around the subject of mass-independent isotope fractionation effects, particularly in the case of the oxygen isotopes. To be sure, the controversy has been around for awhile, but it has been given new impetus by the results of a recent study by Mark H. Thiemens and John E. Heidenreich III of the University of California, San Diego (Science, March 4, 1983).Gustav Arrhenius has been trying to convince the planetary science community that chemical effects in isotope fractionation processes could explain observations in meteorites that appear to be outside of the traditionally understood mass-dependent fractionations (G. Arrhenius, J . L. McCrumb, and N. F. Friedman, Astrophys. Space Sci, 65, 297, 1974). Robert Clayton had made the basic observations of oxygen in carbonaceous chondrites that the slope of the δ17 versus δ18 line was 1 instead of the slope of ½ characteristic of terrestrial rocks and lunar samples (Ann. Rev. Nucl. Part. Sci., 28, 501, 1978). The mass-independent effects were ascribed to the apparent contribution of an ancient presolar system component of O16.

  7. 4π Noncoplanar Stereotactic Body Radiation Therapy for Head-and-Neck Cancer: Potential to Improve Tumor Control and Late Toxicity

    SciTech Connect

    Rwigema, Jean-Claude M.; Nguyen, Dan; Heron, Dwight E.; Chen, Allen M.; Lee, Percy; Wang, Pin-Chieh; Vargo, John A.; Low, Daniel A.; Huq, M. Saiful; Tenn, Stephen; Steinberg, Michael L.; Kupelian, Patrick; Sheng, Ke

    2015-02-01

    Purpose: To evaluate the potential benefit of 4π radiation therapy in recurrent, locally advanced, or metastatic head-and-neck cancer treated with stereotactic body radiation therapy (SBRT). Methods and Materials: Twenty-seven patients with 29 tumors who were treated using SBRT were included. In recurrent disease (n=26), SBRT was delivered with a median 44 Gy (range, 35-44 Gy) in 5 fractions. Three patients with sinonasal mucosal melanoma, metastatic breast cancer, and primary undifferentiated carcinoma received 35 Gy, 22.5 Gy, and 40 Gy in 5 fractions, respectively. Novel 4π treatment plans were created for each patient to meet the objective that 95% of the planning target volume was covered by 100% of the prescription dose. Doses to organs at risk (OARs) and 50% dose spillage volumes were compared against the delivered clinical SBRT plans. Local control (LC), late toxicity, tumor control probability (TCP), and normal tissue complication probability were determined. Results: Using 4π plans, mean/maximum doses to all OARs were reduced by 22% to 89%/10% to 86%. With 4π plans, the 50% dose spillage volume was decreased by 33%. Planning target volume prescription dose escalation by 10 Gy and 20 Gy were achieved while keeping doses to OARs significantly improved or unchanged from clinical plans, except for the carotid artery maximum dose at 20-Gy escalation. At a median follow-up of 10 months (range, 1-41 months), crude LC was 52%. The 2-year LC of 39.2% approximated the predicted mean TCP of 42.2%, which increased to 45.9% with 4π plans. For 10-Gy and 20-Gy dose escalation, 4π plans increased TCP from 80.1% and 88.1% to 85.5% and 91.4%, respectively. The 7.4% rate of grade ≥3 late toxicity was comparable to the predicted 5.6% mean normal tissue complication probability for OARs, which was significantly reduced by 4π planning at the prescribed and escalated doses. Conclusions: 4π plans may allow dose escalation with significant and consistent

  8. Histopathologic tumor response after induction chemotherapy and stereotactic body radiation therapy for borderline resectable pancreatic cancer

    PubMed Central

    Chuong, Michael D.; Frakes, Jessica M.; Figura, Nicholas; Hoffe, Sarah E.; Shridhar, Ravi; Mellon, Eric A.; Hodul, Pamela J.; Malafa, Mokenge P.; Springett, Gregory M.

    2016-01-01

    Background While clinical outcomes following induction chemotherapy and stereotactic body radiation therapy (SBRT) have been reported for borderline resectable pancreatic cancer (BRPC) patients, pathologic response has not previously been described. Methods This single-institution retrospective review evaluated BRPC patients who completed induction gemcitabine-based chemotherapy followed by SBRT and surgical resection. Each surgical specimen was assigned two tumor regression grades (TRG), one using the College of American Pathologists (CAP) criteria and one using the MD Anderson Cancer Center (MDACC) criteria. Overall survival (OS) and progression free survival (PFS) were correlated to TRG score. Results We evaluated 36 patients with a median follow-up of 13.8 months (range, 6.1-24.8 months). The most common induction chemotherapy regimen (82%) was GTX (gemcitabine, docetaxel, capecitabine). A median SBRT dose of 35 Gy (range, 30-40 Gy) in 5 fractions was delivered to the region of vascular involvement. The margin-negative resection rate was 97.2%. Improved response according to MDACC grade trended towards superior PFS (P=061), but not OS. Any neoadjuvant treatment effect according to MDACC scoring (IIa-IV vs. I) was associated with improved OS and PFS (both P=0.019). We found no relationship between CAP score and OS or PFS. Conclusions These data suggest that the increased pathologic response after induction chemotherapy and SBRT is correlated with improved survival for BRPC patients. PMID:27034789

  9. Reliability of the Bony Anatomy in Image-Guided Stereotactic Radiotherapy of Brain Metastases

    SciTech Connect

    Guckenberger, Matthias Baier, Kurt; Guenther, Iris; Richter, Anne; Wilbert, Juergen; Sauer, Otto; Vordermark, Dirk; Flentje, Michael

    2007-09-01

    Purpose: To evaluate whether the position of brain metastases remains stable between planning and treatment in cranial stereotactic radiotherapy (SRT). Methods and Materials: Eighteen patients with 20 brain metastases were treated with single-fraction (17 lesions) or hypofractionated (3 lesions) image-guided SRT. Median time interval between planning and treatment was 8 days. Before treatment a cone-beam CT (CBCT) and a conventional CT after application of i.v. contrast were acquired. Setup errors using automatic bone registration (CBCT) and manual soft-tissue registration of the brain metastases (conventional CT) were compared. Results: Tumor size was not significantly different between planning and treatment. The three-dimensional setup error (mean {+-} SD) was 4.0 {+-} 2.1 mm and 3.5 {+-} 2.2 mm according to the bony anatomy and the lesion itself, respectively. A highly significant correlation between automatic bone match and soft-tissue registration was seen in all three directions (r {>=} 0.88). The three-dimensional distance between the isocenter according to bone match and soft-tissue registration was 1.7 {+-} 0.7 mm, maximum 2.8 mm. Treatment of intracranial pressure with steroids did not influence the position of the lesion relative to the bony anatomy. Conclusion: With a time interval of approximately 1 week between planning and treatment, the bony anatomy of the skull proved to be an excellent surrogate for the target position in image-guided SRT.

  10. Monte Carlo calculation of dose distributions in oligometastatic patients planned for spine stereotactic ablative radiotherapy.

    PubMed

    Moiseenko, V; Liu, M; Loewen, S; Kosztyla, R; Vollans, E; Lucido, J; Fong, M; Vellani, R; Popescu, I A

    2013-10-21

    Dosimetric consequences of plans optimized using the analytical anisotropic algorithm (AAA) implemented in the Varian Eclipse treatment planning system for spine stereotactic body radiotherapy were evaluated by re-calculating with BEAMnrc/DOSXYZnrc Monte Carlo. Six patients with spinal vertebral metastases were planned using volumetric modulated arc therapy. The planning goal was to cover at least 80% of the planning target volume with a prescribed dose of 35 Gy in five fractions. Tissue heterogeneity-corrected AAA dose distributions for the planning target volume and spinal canal planning organ-at-risk volume were compared against those obtained from Monte Carlo. The results showed that the AAA overestimated planning target volume coverage with the prescribed dose by up to 13.5% (mean 8.3% +/- 3.2%) when compared to Monte Carlo simulations. Maximum dose to spinal canal planning organ-at-risk volume calculated with Monte Carlo was consistently smaller than calculated with the treatment planning system and remained under spinal cord dose tolerance. Differences in dose distribution appear to be related to the dosimetric effects of accounting for body composition in Monte Carlo simulations. In contrast, the treatment planning system assumes that all tissues are water-equivalent in their composition and only differ in their electron density.

  11. Stereotactic radiosurgery (SRS) in the modern management of patients with brain metastases

    PubMed Central

    Soliman, Hany; Das, Sunit; Larson, David A.; Sahgal, Arjun

    2016-01-01

    Stereotactic radiosurgery (SRS) is an established non-invasive ablative therapy for brain metastases. Early clinical trials with SRS proved that tumor control rates are superior to whole brain radiotherapy (WBRT) alone. As a result, WBRT plus SRS was widely adopted for patients with a limited number of brain metastases (“limited number” customarily means 1-4). Subsequent trials focused on answering whether WBRT upfront was necessary at all. Based on current randomized controlled trials (RCTs) and meta-analyses comparing SRS alone to SRS plus WBRT, adjuvant WBRT results in better intracranial control; however, at the expense of neurocognitive functioning and quality of life. These adverse effects of WBRT may also negatively impact on survival in younger patients. Based on the results of these studies, treatment has shifted to SRS alone in patients with a limited number of metastases. Additionally, RCTs are evaluating the role of SRS alone in patients with >4 brain metastases. New developments in SRS include fractionated SRS for large tumors and the integration of SRS with targeted systemic therapies that cross the blood brain barrier and/or stimulate an immune response. We present in this review the current high level evidence and rationale supporting SRS as the standard of care for patients with limited brain metastases, and emerging applications of SRS. PMID:26848525

  12. Effect of bite tray impression technique on relocation accuracy in frameless stereotactic radiotherapy

    SciTech Connect

    Herbert, Clare E.; Ebert, Martin A.; Barclay, D.; Whittall, David S.; Joseph, David J.; Harper, Chris S.; Spry, Nigel A

    2003-03-31

    A previously developed method for achieving patient relocation in fractionated stereotactic radiotherapy (attachment of an infrared fiducial system to a bite tray) relies on the integrity of a bite tray system that incorporates moulding to the patient's upper dentition. Reproducible and accurate patient positioning requires stability of the bite tray and mould during the full treatment process, both during the time the bite tray is inserted in the patient's mouth, and between separate bite tray insertions. The optimum construction method for a stable reproducible tray has not been sufficiently investigated. We undertook a study to identify factors which might influence the integrity of the hard palate bite tray system. Reprosil Fast Set Putty was used to construct 3 impression conditions; teeth only; teeth and alveolar sulcus; and teeth, alveolar sulcus, and the hard palate. Reproducibility was assessed by volunteers inserting the impressions multiple times and recording the locations of 8 standard reference points. Our results showed the optimal impression technique (i.e., the one that led to the smallest ranges in positional and rotational errors) was that which incorporated the teeth, alveolar sulcus, and hard palate.

  13. Stereotactic Body Radiation Therapy Delivery in a Genetically Engineered Mouse Model of Lung Cancer

    PubMed Central

    Du, Shisuo; Lockamy, Virginia; Zhou, Lin; Xue, Christine; LeBlanc, Justin; Glenn, Shonna; Shukla, Gaurav; Yu, Yan; Dicker, Adam P.; Leeper, Dennis B.; Lu, You; Lu, Bo

    2016-01-01

    Purpose To implement clinical stereotactic body radiation therapy (SBRT) using a small animal radiation research platform (SARRP) in a genetically engineered mouse model of lung cancer. Methods and Materials A murine model of multinodular Kras-driven spontaneous lung tumors was used for this study. High-resolution cone beam computed tomography (CBCT) imaging was used to identify and target peripheral tumor nodules, whereas off-target lung nodules in the contralateral lung were used as a nonirradiated control. CBCT imaging helps localize tumors, facilitate high-precision irradiation, and monitor tumor growth. SBRT planning, prescription dose, and dose limits to normal tissue followed the guidelines set by RTOG protocols. Pathologic changes in the irradiated tumors were investigated using immunohistochemistry. Results The image guided radiation delivery using the SARRP system effectively localized and treated lung cancer with precision in a genetically engineered mouse model of lung cancer. Immunohistochemical data confirmed the precise delivery of SBRT to the targeted lung nodules. The 60 Gy delivered in 3 weekly fractions markedly reduced the proliferation index, Ki-67, and increased apoptosis per staining for cleaved caspase-3 in irradiated lung nodules. Conclusions It is feasible to use the SARRP platform to perform dosimetric planning and delivery of SBRT in mice with lung cancer. This allows for preclinical studies that provide a rationale for clinical trials involving SBRT, especially when combined with immunotherapeutics. PMID:27681749

  14. Verification of dose volume histograms in stereotactic radiosurgery and radiotherapy using polymer gel and MRI

    NASA Astrophysics Data System (ADS)

    Šemnická, Jitka; Novotný, Josef, Jr.; Spěváček, Václav; Garčic, Jirí; Steiner, Martin; Judas, Libor

    2006-12-01

    In this work we focus on dose volume histograms (DVHs) measurement in stereotactic radiosurgery (SR) performed with the Leksell gamma knife (ELEKTA Instrument AB, Stockholm, Sweden) and stereotactic radiotherapy (SRT) performed with linear accelerator 6 MV Varian Clinac 2100 C/D (Varian Medical Systems, Palo Alto, USA) in conjunction with BrainLAB stereotactic system (BrainLAB, Germany) using modified BANG gel and magnetic resonance imaging (MRI). The aim of the experiments was to investigate a method for acquiring entire dose volume information from irradiated gel dosimeter and calculate DVHs.

  15. Lung Volume Reduction After Stereotactic Ablative Radiation Therapy of Lung Tumors: Potential Application to Emphysema

    SciTech Connect

    Binkley, Michael S.; Shrager, Joseph B.; Leung, Ann N.; Popat, Rita; Trakul, Nicholas; Atwood, Todd F.; Chaudhuri, Aadel; Maxim, Peter G.; Diehn, Maximilian; Loo, Billy W.

    2014-09-01

    Purpose: Lung volume reduction surgery (LVRS) improves dyspnea and other outcomes in selected patients with severe emphysema, but many have excessive surgical risk for LVRS. We analyzed the dose-volume relationship for lobar volume reduction after stereotactic ablative radiation therapy (SABR) of lung tumors, hypothesizing that SABR could achieve therapeutic volume reduction if applied in emphysema. Methods and Materials: We retrospectively identified patients treated from 2007 to 2011 who had SABR for 1 lung tumor, pre-SABR pulmonary function testing, and ≥6 months computed tomographic (CT) imaging follow-up. We contoured the treated lobe and untreated adjacent lobe(s) on CT before and after SABR and calculated their volume changes relative to the contoured total (bilateral) lung volume (TLV). We correlated lobar volume reduction with the volume receiving high biologically effective doses (BED, α/β = 3). Results: 27 patients met the inclusion criteria, with a median CT follow-up time of 14 months. There was no grade ≥3 toxicity. The median volume reduction of the treated lobe was 4.4% of TLV (range, −0.4%-10.8%); the median expansion of the untreated adjacent lobe was 2.6% of TLV (range, −3.9%-11.6%). The volume reduction of the treated lobe was positively correlated with the volume receiving BED ≥60 Gy (r{sup 2}=0.45, P=.0001). This persisted in subgroups determined by high versus low pre-SABR forced expiratory volume in 1 second, treated lobe CT emphysema score, number of fractions, follow-up CT time, central versus peripheral location, and upper versus lower lobe location, with no significant differences in effect size between subgroups. Volume expansion of the untreated adjacent lobe(s) was positively correlated with volume reduction of the treated lobe (r{sup 2}=0.47, P<.0001). Conclusions: We identified a dose-volume response for treated lobe volume reduction and adjacent lobe compensatory expansion after lung tumor SABR, consistent across

  16. Stereotactic radiotherapy in neovascular age-related macular degeneration

    PubMed Central

    Ranjbar, Mahdy; Kurz, Maximilian; Holzhey, Annekatrin; Melchert, Corinna; Rades, Dirk; Grisanti, Salvatore

    2016-01-01

    Abstract Stereotactic radiotherapy (SRT) is a new approach to treat neovascular age-related macular degeneration (nAMD). The INTREPID trial suggested that SRT could reduce the frequency of regular intravitreal injections (IVIs) with antivascular endothelial growth factor drugs, which are necessary to control disease activity. However, the efficacy of SRT in nAMD and resulting morphological changes have not been validated under real-life circumstances, an issue, which we would like to address in this retrospective analysis. Patients who met the INTREPID criteria for best responders were eligible for SRT. A total of 32 eyes of 32 patients were treated. Thereafter, patients were examined monthly for 12 months and received pro re nata IVI of aflibercept or ranibizumab. Outcome measures were: mean number of injections, best-corrected visual acuity, and morphological changes of the outer retina-choroid complex as well as patient safety. Mean number of IVI decreased by almost 50% during the 12 months after SRT compared to the year before, whereas visual acuity increased by one line (logMAR). Morphological evaluation showed that most changes affect outer retinal layers. Stereotactic radiotherapy significantly reduced IVI retreatment in nAMD patients under real-life circumstances. Therefore, SRT might be the first step to stop visual loss as a result of IVI undertreatment, which is a major risk. PMID:28033280

  17. Current status of cranial stereotactic radiosurgery in the UK

    PubMed Central

    Kirkby, Karen J; Nisbet, Andrew; Clark, Catharine H

    2016-01-01

    Objective: To investigate and benchmark the current clinical and dosimetric practices in stereotactic radiosurgery (SRS) in the UK. Methods: A detailed questionnaire was sent to 70 radiotherapy centres in the UK. 97% (68/70) of centres replied between June and December 2014. Results: 21 centres stated that they are practising SRS, and a further 12 centres plan to start SRS by the end of 2016. The most commonly treated indications are brain metastases and acoustic neuromas. A large range of prescription isodoses that range from 45% to 100% between different radiotherapy centres was seen. Ionization chambers and solid-water phantoms are used by the majority of centres for patient-specific quality assurance, and thermoplastic masks for patient immobilization are more commonly used than fixed stereotactic frames. The majority of centres perform orthogonal kilovoltage X-rays for localization before and during delivery. The acceptable setup accuracy reported ranges from 0.1 to 2 mm with a mean of 0.8 mm. Conclusion: SRS has been increasing in use in the UK and will continue to increase in the next 2 years. There is no current consensus between SRS centres as a whole, or even between SRS centres with the same equipment, on the practices followed. This indicates the need for benchmarking and standardization in SRS practices within the UK. Advances in knowledge: This article outlines the current practices in SRS and provides a benchmark for reference and comparison with future research in this technique. PMID:26689091

  18. Temporal compartmental dosing effects for robotic prostate stereotactic body radiotherapy

    NASA Astrophysics Data System (ADS)

    Shiao, Stephen L.; Sahgal, Arjun; Hu, Weigang; Jabbari, Siavash; Chuang, Cynthia; Descovich, Martina; Hsu, I.-Chow; Gottschalk, Alexander R.; Roach, Mack, III; Ma, Lijun

    2011-12-01

    The rate of dose accumulation within a given area of a target volume tends to vary significantly for non-isocentric delivery systems such as Cyberknife stereotactic body radiotherapy. In this study, we investigated whether intra-target temporal dose distributions produce significant variations in the biological equivalent dose. For the study, time courses of ten patients were reconstructed and calculation of a biologically equivalent uniform dose (EUD) was performed using a formula derived from the linear quadratic model (α/β = 3 for prostate cancer cells). The calculated EUD values obtained for the actual patient treatments were then compared with theoretical EUD values for delivering the same physical dose distribution except that the whole target being irradiated continuously (e.g. large-field ‘dose-bathing’ type of delivery). For all the case, the EUDs for the actual treatment delivery were found to correlate strongly with the EUDs for the large-field delivery: a linear correlation coefficient of R2 = 0.98 was obtained and the average EUD for the actual Cyberknife delivery was somewhat higher (5.0 ± 4.7%) than that for the large-field delivery. However, no statistical significance was detected between the two types of delivery (p = 0.21). We concluded that non-isocentric small-field Cyberknife delivery produced consistent biological dosing that tracked well with the constant-dose-rate, large-field-type delivery for prostate stereotactic body radiotherapy.

  19. Single- versus Multifraction Stereotactic Body Radiation Therapy for Pancreatic Adenocarcinoma: Outcomes and Toxicity

    SciTech Connect

    Pollom, Erqi L.; Alagappan, Muthuraman; Eyben, Rie von; Kunz, Pamela L.; Fisher, George A.; Ford, James A.; Poultsides, George A.; Visser, Brendan C.; Norton, Jeffrey A.; Kamaya, Aya; Cox, Veronica L.; Columbo, Laurie A.; Koong, Albert C.; Chang, Daniel T.

    2014-11-15

    Purpose: We report updated outcomes of single- versus multifraction stereotactic body radiation therapy (SBRT) for unresectable pancreatic adenocarcinoma. Methods and Materials: We included 167 patients with unresectable pancreatic adenocarcinoma treated at our institution from 2002 to 2013, with 1-fraction (45.5% of patient) or 5-fraction (54.5% of patients) SBRT. The majority of patients (87.5%) received chemotherapy. Results: Median follow-up was 7.9 months (range: 0.1-63.6). The 6- and 12-month cumulative incidence rates (CIR) of local recurrence for patients treated with single-fraction SBRT were 5.3% (95% confidence interval [CI], 0.2%-10.4%) and 9.5% (95% CI, 2.7%-16.2%), respectively. The 6- and 12-month CIR with multifraction SBRT were 3.4% (95% CI, 0.0-7.2%) and 11.7% (95% CI, 4.8%-18.6%), respectively. Median survival from diagnosis for all patients was 13.6 months (95% CI, 12.2-15.0 months). The 6- and 12- month survival rates from SBRT for the single-fraction group were 67.0% (95% CI, 57.2%-78.5%) and 30.8% (95% CI, 21.9%-43.6%), respectively. The 6- and 12- month survival rates for the multifraction group were 75.7% (95% CI, 67.2%-85.3%) and 34.9% (95% CI, 26.1%-46.8%), respectively. There were no differences in CIR or survival rates between the single- and multifraction groups. The 6- and 12-month cumulative incidence rates of gastrointestinal toxicity grade ≥3 were 8.1% (95% CI, 1.8%-14.4%) and 12.3% (95% CI, 4.7%-20.0%), respectively, in the single-fraction group, and both were 5.6% (95% CI, 0.8%-10.5%) in the multifraction group. There were significantly fewer instances of toxicity grade ≥2 with multifraction SBRT (P=.005). Local recurrence and toxicity grade ≥2 were independent predictors of worse survival. Conclusions: Multifraction SBRT for pancreatic cancer significantly reduces gastrointestinal toxicity without compromising local control.

  20. Interfraction variation in lung tumor position with abdominal compression during stereotactic body radiotherapy

    SciTech Connect

    Mampuya, Wambaka Ange; Nakamura, Mitsuhiro; Matsuo, Yukinori; Ueki, Nami; Iizuka, Yusuke; Monzen, Hajime; Mizowaki, Takashi; Hiraoka, Masahiro; Fujimoto, Takahiro; Yano, Shinsuke

    2013-09-15

    Purpose: To assess the effect of abdominal compression on the interfraction variation in tumor position in lung stereotactic body radiotherapy (SBRT) using cone-beam computed tomography (CBCT) in a larger series of patients with large tumor motion amplitude.Methods: Thirty patients with lung tumor motion exceeding 8 mm who underwent SBRT were included in this study. After translational and rotational initial setup error was corrected based on bone anatomy, CBCT images were acquired for each fraction. The residual interfraction variation was defined as the difference between the centroid position of the visualized target in three dimensions derived from CBCT scans and those derived from averaged intensity projection images. The authors compared the magnitude of the interfraction variation in tumor position between patients treated with [n= 16 (76 fractions)] and without [n= 14 (76 fractions)] abdominal compression.Results: The mean ± standard deviation (SD) of the motion amplitude in the longitudinal direction before abdominal compression was 19.9 ± 7.3 (range, 10–40) mm and was significantly (p < 0.01) reduced to 12.4 ± 5.8 (range, 5–30) mm with compression. The greatest variance of the interfraction variation with abdominal compression was observed in the longitudinal direction, with a mean ± SD of 0.79 ± 3.05 mm, compared to −0.60 ± 2.10 mm without abdominal compression. The absolute values of the 95th percentile of the interfraction variation for one side in each direction were 3.97/6.21 mm (posterior/anterior), 4.16/3.76 mm (caudal/cranial), and 2.90/2.32 mm (right/left) without abdominal compression, and 2.14/5.03 mm (posterior/anterior), 3.93/9.23 mm (caudal/cranial), and 2.37/5.45 mm (right/left) with abdominal compression. An absolute interfraction variation greater than 5 mm was observed in six (9.2%) fractions without and 13 (17.1%) fractions with abdominal compression.Conclusions: Abdominal compression was effective for reducing the amplitude

  1. Gas Chromatography-Quadrupole Time-of-Flight Mass Spectrometry-Based Determination of Isotopologue and Tandem Mass Isotopomer Fractions of Primary Metabolites for (13)C-Metabolic Flux Analysis.

    PubMed

    Mairinger, Teresa; Steiger, Matthias; Nocon, Justyna; Mattanovich, Diethard; Koellensperger, Gunda; Hann, Stephan

    2015-12-01

    For the first time an analytical work flow based on accurate mass gas chromatography-quadrupole time-of-flight mass spectrometry (GC-QTOFMS) with chemical ionization for analysis providing a comprehensive picture of (13)C distribution along the primary metabolism is elaborated. The method provides a powerful new toolbox for (13)C-based metabolic flux analysis, which is an emerging strategy in metabolic engineering. In this field, stable isotope tracer experiments based on, for example, (13)C are central for providing characteristic patterns of labeled metabolites, which in turn give insights into the regulation of metabolic pathway kinetics. The new method enables the analysis of isotopologue fractions of 42 free intracellular metabolites within biotechnological samples, while tandem mass isotopomer information is also accessible for a large number of analytes. Hence, the method outperforms previous approaches in terms of metabolite coverage, while also providing rich isotopomer information for a significant number of key metabolites. Moreover, the established work flow includes novel evaluation routines correcting for isotope interference of naturally distributed elements, which is crucial following derivatization of metabolites. Method validation in terms of trueness, precision, and limits of detection was performed, showing excellent analytical figures of merit with an overall maximum bias of 5.8%, very high precision for isotopologue and tandem mass isotopomer fractions representing >10% of total abundance, and absolute limits of detection in the femtomole range. The suitability of the developed method is demonstrated on a flux experiment of Pichia pastoris employing two different tracers, i.e., 1,6(13)C2-glucose and uniformly labeled (13)C-glucose.

  2. Stereotactic Body Radiotherapy for Lesions of the Spine and Paraspinal Regions

    SciTech Connect

    Nelson, John W.; Yoo, David S.; Sampson, John H.; Isaacs, Robert E.; Larrier, Nicole A.; Marks, Lawrence B.; Yin Fangfang; Wu, Q. Jackie; Wang Zhiheng; Kirkpatrick, John P.

    2009-04-01

    Purpose: To describe our experience and clinical strategy for stereotactic body radiotherapy (SBRT) of spinal lesions. Methods and Materials: Thirty-two patients with 33 spinal lesions underwent computed tomography-based simulation while free breathing. Gross/clinical target volumes included involved portions of the vertebral body and paravertebral/epidural tumor. Planning target volume (PTV) expansion was 6 mm axially and 3 mm radially; the cord was excluded from the PTV. Biologic equivalent dose was calculated using the linear quadratic model with {alpha}/{beta} = 3 Gy. Treatment was linear accelerator based with on-board imaging; dose was adjusted to maintain cord dose within tolerance. Survival, local control, pain, and neurologic status were monitored. Results: Twenty-one patients are alive at 1 year (median survival, 14 months). Median follow-up is 6 months for all patients (7 months for survivors). Mean previous radiotherapy dose to 22 patients was 35 Gy, and median interval was 17 months. Renal (31%), breast, and lung (19% each) were the most common histologic sites. Three SBRT fractions (range, one to four fractions) of 7 Gy (range, 5-16 Gy) were delivered. Median cord and target biologic equivalent doses were 70 Gy{sub 3} and 34.3 Gy{sub 10}, respectively. Thirteen patients reported complete and 17 patients reported partial pain relief at 1 month. There were four failures (mean, 5.8 months) with magnetic resonance imaging evidence of in-field progression. No dosimetric parameters predictive of failure were identified. No treatment-related toxicity was seen. Conclusions: Spinal SBRT is effective in the palliative/re-treatment setting. Volume expansion must ensure optimal PTV coverage while avoiding spinal cord toxicity. The long-term safety of spinal SBRT and the applicability of the linear-quadratic model in this setting remain to be determined, particularly the time-adjusted impact of prior radiotherapy.

  3. Dose Escalated Liver Stereotactic Body Radiation Therapy at the Mean Respiratory Position

    SciTech Connect

    Velec, Michael; Moseley, Joanne L.; Dawson, Laura A.; Brock, Kristy K.

    2014-08-01

    Purpose: The dosimetric impact of dose probability based planning target volume (PTV) margins for liver cancer patients receiving stereotactic body radiation therapy (SBRT) was compared with standard PTV based on the internal target volume (ITV). Plan robustness was evaluated by accumulating the treatment dose to ensure delivery of the intended plan. Methods and Materials: Twenty patients planned on exhale CT for 27 to 50 Gy in 6 fractions using an ITV-based PTV and treated free-breathing were retrospectively evaluated. Isotoxic, dose escalated plans were created on midposition computed tomography (CT), representing the mean breathing position, using a dose probability PTV. The delivered doses were accumulated using biomechanical deformable registration of the daily cone beam CT based on liver targeting at the exhale or mean breathing position, for the exhale and midposition CT plans, respectively. Results: The dose probability PTVs were on average 38% smaller than the ITV-based PTV, enabling an average ± standard deviation increase in the planned dose to 95% of the PTV of 4.0 ± 2.8 Gy (9 ± 5%) on the midposition CT (P<.01). For both plans, the delivered minimum gross tumor volume (GTV) doses were greater than the planned nominal prescribed dose in all 20 patients and greater than the planned dose to 95% of the PTV in 18 (90%) patients. Nine patients (45%) had 1 or more GTVs with a delivered minimum dose more than 5 Gy higher with the midposition CT plan using dose probability PTV, compared with the delivered dose with the exhale CT plan using ITV-based PTV. Conclusions: For isotoxic liver SBRT planned and delivered at the mean respiratory, reduced dose probability PTV enables a mean escalation of 4 Gy (9%) in 6 fractions over ITV-based PTV. This may potentially improve local control without increasing the risk of tumor underdosing.

  4. Hypofractionated Stereotactic Radiation Therapy in Recurrent High-Grade Glioma: A New Challenge

    PubMed Central

    Navarria, Pierina; Ascolese, Anna Maria; Tomatis, Stefano; Reggiori, Giacomo; Clerici, Elena; Villa, Elisa; Maggi, Giulia; Bello, Lorenzo; Pessina, Federico; Cozzi, Luca; Scorsetti, Marta

    2016-01-01

    Purpose The aim of this study was to evaluate outcomes of hypofractionated stereotactic radiation therapy (HSRT) in patients re-treated for recurrent high-grade glioma. Materials and Methods From January 2006 to September 2013, 25 patients were treated. Six patients underwent radiation therapy alone, while 19 underwent combined treatment with surgery and/or chemotherapy. Only patients with Karnofsky Performance Status (KPS) > 70 and time from previous radiotherapy greater than 6 months were re-irradiated. The mean recurrent tumor volume was 35 cm3 (range, 2.46 to 116.7 cm3), and most of the patients (84%) were treated with a total dose of 25 Gy in five fractions (range, 20 to 50 Gy in 5-10 fractions). Results The median follow-up was 18 months (range, 4 to 36 months). The progression-free survival (PFS) at 1 and 2 years was 72% and 34% and the overall survival (OS) 76% and 50%, respectively. No severe toxicity was recorded. In univariate and multivariate analysis extent of resection at diagnosis significantly influenced PFS and OS (p < 0.01). Patients with smaller recurren tumor volume treated had better local control and survival. Indeed, the 2-year PFS was 40% (≤ 50 cm3) versus 11% (p=0.1) and the 2-year OS 56% versus 33% (> 50 cm3), respectively (p=0.26). Conclusion In our experience, HSRT could be a safe and feasible therapeutic option for recurrent high grade glioma even in patients with larger tumors. We believe that a multidisciplinary evaluation is mandatory to assure the best treatment for selected patients. Local treatment should also be considered as part of an integrated approach. PMID:25761491

  5. Obesity Increases the Risk of Chest Wall Pain From Thoracic Stereotactic Body Radiation Therapy

    SciTech Connect

    Welsh, James; Thomas, Jimmy; Shah, Deep; Allen, Pamela K.; Wei, Xiong; Mitchell, Kevin; Gao, Song; Balter, Peter; Komaki, Ritsuko; Chang, Joe Y.

    2011-09-01

    Purpose: Stereotactic body radiation therapy (SBRT) is increasingly being used to treat thoracic tumors. We attempted here to identify dose-volume parameters that predict chest wall toxicity (pain and skin reactions) in patients receiving thoracic SBRT. Patients and Methods: We screened a database of patients treated with SBRT between August 2004 and August 2008 to find patients with pulmonary tumors within 2.5 cm of the chest wall. All patients received a total dose of 50 Gy in four daily 12.5-Gy fractions. Toxicity was scored according to the NCI-CTCAE V3.0. Results: Of 360 patients in the database, 265 (268 tumors) had tumors within <2.5 cm of the chest wall; 104 (39%) developed skin toxicity (any grade); 14 (5%) developed acute pain (any grade), and 45 (17%) developed chronic pain (Grade 1 in 22 cases [49%] and Grade 2 or 3 in 23 cases [51%]). Both skin toxicity and chest wall pain were associated with the V{sub 30}, or volume of the chest wall receiving 30 Gy. Body mass index (BMI) was also strongly associated with the development of chest pain: patients with BMI {>=}29 had almost twice the risk of chronic pain (p = 0.03). Among patients with BMI >29, diabetes mellitus was a significant contributing factor to the development of chest pain. Conclusion: Safe use of SBRT with 50 Gy in four fractions for lesions close to the chest wall requires consideration of the chest wall volume receiving 30 Gy and the patient's BMI and diabetic state.

  6. Dosimetric comparison of patient setup strategies in stereotactic body radiation therapy for lung cancer

    SciTech Connect

    Wu Jianzhou; He, Tongming T.; Betzing, Christopher; Fuss, Martin; D'Souza, Warren D.

    2013-05-15

    Purpose: In this work, the authors retrospectively compared the accumulated dose over the treatment course for stereotactic body radiation therapy (SBRT) of lung cancer for three patient setup strategies. Methods: Ten patients who underwent lung SBRT were selected for this study. At each fraction, patients were immobilized using a vacuum cushion and were CT scanned. Treatment plans were performed on the simulation CT. The planning target volume (PTV) was created by adding a 5-mm uniform margin to the internal target volume derived from the 4DCT. All plans were normalized such that 99% of the PTV received 60 Gy. The plan parameters were copied onto the daily CT images for dose recalculation under three setup scenarios: skin marker, bony structure, and soft tissue based alignments. The accumulated dose was calculated by summing the dose at each fraction along the trajectory of a voxel over the treatment course through deformable image registration of each CT with the planning CT. The accumulated doses were analyzed for the comparison of setup accuracy. Results: The tumor volume receiving 60 Gy was 91.7 {+-} 17.9%, 74.1 {+-} 39.1%, and 99.6 {+-} 1.3% for setup using skin marks, bony structures, and soft tissue, respectively. The isodose line covering 100% of the GTV was 55.5 {+-} 7.1, 42.1 {+-} 16.0, and 64.3 {+-} 7.1 Gy, respectively. The corresponding average biologically effective dose of the tumor was 237.3 {+-} 29.4, 207.4 {+-} 61.2, and 258.3 {+-} 17.7 Gy, respectively. The differences in lung biologically effective dose, mean dose, and V20 between the setup scenarios were insignificant. Conclusions: The authors' results suggest that skin marks and bony structure are insufficient for aligning patients in lung SBRT. Soft tissue based alignment is needed to match the prescribed dose delivered to the tumors.

  7. Hypofractionated stereotactic body radiotherapy in low- and intermediate-risk prostate carcinoma

    PubMed Central

    Kim, Hun Jung; Phak, Jeong Hoon; Kim, Woo Chul

    2016-01-01

    Purpose Stereotactic body radiotherapy (SBRT) takes advantage of low α/β ratio of prostate cancer to deliver a large dose in few fractions. We examined clinical outcomes of SBRT using CyberKnife for the treatment of low- and intermediate-risk prostate cancer. Materials and Methods This study was based on a retrospective analysis of the 33 patients treated with SBRT using CyberKnife for localized prostate cancer (27.3% in low-risk and 72.7% in intermediate-risk). Total dose of 36.25 Gy in 5 fractions of 7.25 Gy were administered. The acute and late toxicities were recorded using the Radiation Therapy Oncology Group scale. Prostate-specific antigen (PSA) response was monitored. Results Thirty-three patients with a median 51 months (range, 6 to 71 months) follow-up were analyzed. There was no biochemical failure. Median PSA nadir was 0.27 ng/mL at median 33 months and PSA bounce occurred in 30.3% (n = 10) of patients at median at median 10.5 months after SBRT. No grade 3 acute toxicity was noted. The 18.2% of the patients had acute grade 2 genitourinary (GU) toxicities and 21.2% had acute grade 2 gastrointestinal (GI) toxicities. After follow-up of 2 months, most complications had returned to baseline. There was no grade 3 late GU and GI toxicity. Conclusion Our experience with SBRT using CyberKnife in low- and intermediate-risk prostate cancer demonstrates favorable efficacy and toxicity. Further studies with more patients and longer follow-up duration are required. PMID:27306777

  8. Clinical Evaluation of an Immbolization System for Stereotactic Body Radiotherapy Using Helical Tomotherapy

    SciTech Connect

    Gutierrez, Alonso N.; Stathakis, Sotirios; Crownover, Richard; Esquivel, Carlos; Shi Chengyu; Papanikolaou, Niko

    2011-07-01

    In this study, a clinical evaluation of the Body Pro-Lok{sup TM} System combined with the TomoTherapy megavoltage computed tomography (MVCT) was performed for lung and liver stereotactic body radiotherapy (SBRT) to reduce interfractional setup uncertainty. Twenty patients treated with 3-5 fractions of SBRT were analyzed retrospectively. The Body Pro-Lok{sup TM} system was used in both CT simulation and during patient treatment setup. Patients were immobilized with a vacuum cushion placed posteriorly over the thoracic region, an abdominal compression plate, and a knee and foot sponge. Pretreatment MVCT scans of the TomoTherapy HI-ART II unit were fused with the planning kVCT before delivery of each fraction to determine the interfractional setup error. A total of 84 shifts were analyzed to assess the interfractional setup accuracy. Results showed that the mean interfractional setup errors and standard deviations were -0.9 {+-} 3.1 mm, 1.2 {+-} 5.5 mm, and 6.5 {+-} 2.6 mm for lateral (IEC-X), longitudinal (IEC-Y), and vertical (IEC-Z) variations, respectively. The maximum motion was 17.1 mm in the longitudinal direction. When all 3 translational coordinates were analyzed, a mean composite displacement vector of 8.2 {+-} 2.0 mm (range 4.1-11.7 mm) was obtained for all patients. Based on the findings, image-guided SBRT using the Body Pro-Lok{sup TM} system in conjunction with the MVCT of TomoTherapy is capable of minimizing interfractional setup error and improving treatment accuracy.

  9. Stereotactic body radiation therapy of liver tumors: post-treatment appearances and evaluation of treatment response: a pictorial review.

    PubMed

    Haddad, Mustafa M; Merrell, Kenneth W; Hallemeier, Christopher L; Johnson, Geoffrey B; Mounajjed, Taofic; Olivier, Kenneth R; Fidler, Jeff L; Venkatesh, Sudhakar K

    2016-10-01

    Stereotactic body radiation therapy (SBRT) is a noninvasive treatment technique for selected patients with primary liver tumors and liver-confined oligometastatic disease. Recently, SBRT has emerged as an alternative treatment option in non-surgical candidates and in whom percutaneous treatment methods are not possible or contraindicated. The experience with SBRT continues to grow. There are currently no imaging guidelines for assessment of tumor response and follow-up schedule following SBRT. SBRT produces characteristic radiation-induced changes in the treated tumor and surrounding liver parenchyma. Knowledge of these changes is essential in the interpretation of follow-up imaging and assessment of treatment response. In this review, we will describe the CT, MRI, and PET imaging findings following SBRT of both the targeted liver tumor and surrounding hepatic parenchyma.

  10. Stereotactic Image-Guided Intensity Modulated Radiotherapy Using the HI-ART II Helical Tomotherapy System

    SciTech Connect

    Holmes, Timothy W. Hudes, Richard; Dziuba, Sylwester; Kazi, Abdul; Hall, Mark; Dawson, Dana

    2008-07-01

    The highly integrated adaptive radiation therapy (HI-ART II) helical tomotherapy unit is a new radiotherapy machine designed to achieve highly precise and accurate treatments at all body sites. The precision and accuracy of the HI-ART II is similar to that provided by stereotactic radiosurgery systems, hence the historical distinction between external beam radiotherapy and stereotactic procedures based on differing precision requirements is removed for this device. The objectives of this work are: (1) to describe stereotactic helical tomotherapy processes (SRS, SBRT); (2) to show that the precision and accuracy of the HI-ART meet the requirements defined for SRS and SBRT; and (3) to describe the clinical implementation of a stereotactic image-guided intensity modulated radiation therapy (IG-IMRT) system that incorporates optical motion management.

  11. Characteristics and Treatments of Large Cystic Brain Metastasis: Radiosurgery and Stereotactic Aspiration

    PubMed Central

    Kim, Moinay; Cheok, Stephanie; Chung, Lawrance K.; Ung, Nolan; Thill, Kimberly; Voth, Brittany; Kwon, Do Hoon; Kim, Jeong Hoon; Kim, Chang Jin; Tenn, Stephen; Lee, Percy

    2015-01-01

    Brain metastasis represents one of the most common causes of intracranial tumors in adults, and the incidence of brain metastasis continues to rise due to the increasing survival of cancer patients. Yet, the development of cystic brain metastasis remains a relatively rare occurrence. In this review, we describe the characteristics of cystic brain metastasis and evaluate the combined use of stereotactic aspiration and radiosurgery in treating large cystic brain metastasis. The results of several studies show that stereotactic radiosurgery produces comparable local tumor control and survival rates as other surgery protocols. When the size of the tumor interferes with radiosurgery, stereotactic aspiration of the metastasis should be considered to reduce the target volume as well as decreasing the chance of radiation induced necrosis and providing symptomatic relief from mass effect. The combined use of stereotactic aspiration and radiosurgery has strong implications in improving patient outcomes. PMID:25977901

  12. Modelling 6 MV photon beams of a stereotactic radiosurgery system for Monte Carlo treatment planning

    NASA Astrophysics Data System (ADS)

    Deng, Jun; Guerrero, Thomas; Ma, C.-M.; Nath, Ravinder

    2004-05-01

    The goal of this work is to build a multiple source model to represent the 6 MV photon beams from a Cyberknife stereotactic radiosurgery system for Monte Carlo treatment planning dose calculations. To achieve this goal, the 6 MV photon beams have been characterized and modelled using the EGS4/BEAM Monte Carlo system. A dual source model has been used to reconstruct the particle phase space at a plane immediately above the secondary collimator. The proposed model consists of two circular planar sources for the primary photons and the scattered photons, respectively. The dose contribution of the contaminant electrons was found to be in the order of 10-3 of the total maximum dose and therefore has been omitted in the source model. Various comparisons have been made to verify the dual source model against the full phase space simulated using the EGS4/BEAM system. The agreement in percent depth dose (PDD) curves and dose profiles between the phase space and the source model was generally within 2%/1 mm for various collimators (5 to 60 mm in diameter) at 80 to 100 cm source-to-surface distances (SSD). Excellent agreement (within 1%/1 mm) was also found between the dose distributions in heterogeneous lung and bone geometry calculated using the original phase space and those calculated using the source model. These results demonstrated the accuracy of the dual source model for Monte Carlo treatment planning dose calculations for the Cyberknife system.

  13. SU-E-T-395: Evaluation of Multiple Brain Metastases Stereotactic Treatment Planning in Cyberknife Versus Linac

    SciTech Connect

    Vikraman, S; Rajesh, Thiyagarajan; Karrthick, Kp; Sambasivaselli, R; Senniandavar, V; Ramu, M; Maragathaveni, S; Dhivya, N; Tejinder, K; Manigandan, D; Muthukumaran, M

    2015-06-15

    Purpose: The purpose of this study was to evaluate multiple brain metastases stereotactic treatment planning of Cyberknife versus linac using dose volume based indices. Methods: Fifteen multiple brain metastases patients were taken for this study from Cyberknife Multiplan TPSv4.6.0. All these patients underwent stereotactic treatment in Cyberknife. For each patient VMAT stereotactic treatment plan was generated in MONACO TPSv5.0 using Elekta beam modulator MLC and matched the delivered plan. A median dose of 8.5Gy(range 7–12Gy) per fraction was prescribed. Tumor volume was in the range of 0.06–4.33cc. Treatment plan quality was critically evaluated by comparing DVH indices such as D98, D95, CI, and HI for target volumes. Maximum point doses and volume doses were evaluated for critical organs. Results: For each case, target coverage of D98 was achieved with 100% prescription dose with SD of 0.29% and 0.41% in Linac and Cyberknife respectively. The average conformity index(CI) of 1.26±0.0796 SD for Cyberknife and 1.92±0.60SD for linac were observed. Better homogeneity Index (HI) of 1.17±0.09SD was observed in linac as compared to Cyberknife HI of 1.24±0.05SD.All the critical organ doses were well within tolerance limit in both linac and Cyberknife plans. There is no significant difference of maximum point doses for brainstem and optic chiasm. Treatment time and number of monitor units are more in Cyberknife compared to linac. The average volume receiving 12Gy in whole brain was 6% and 12% for Cyberknife and linac respectively. 1000cc of whole brain received 60% lesser dose in Linac compared to Cyberknife in all cases. Conclusion: The study shows that dosimetrically comparable plans are achievable Cyberknife and Linac. However, a better conformity, target coverage, lesser OAR dose is achieved with Cyberknife due to greater degrees of freedom with robotic gantry and smaller collimator for multiple targets.

  14. Local Tumor Control, Visual Acuity, and Survival After Hypofractionated Stereotactic Photon Radiotherapy of Choroidal Melanoma in 212 Patients Treated Between 1997 and 2007

    SciTech Connect

    Dunavoelgyi, Roman; Dieckmann, Karin; Gleiss, Andreas; Sacu, Stefan; Kircher, Karl; Georgopoulos, Michael; Georg, Dietmar; Zehetmayer, Martin; Poetter, Richard

    2011-09-01

    Purpose: To evaluate long-term local tumor control, visual acuity, and survival after hypofractionated linear accelerator-based stereotactic photon radiotherapy in patients with choroidal melanoma. Methods and Materials: Between 1997 and 2007, 212 patients with choroidal melanoma unsuitable for ruthenium-106 brachytherapy or local resection were treated stereotactically at a linear accelerator with 6-MV photon beams at the Medical University of Vienna in five fractions over 7 days. Twenty-four patients received a total dose of 70 Gy (five fractions of 14 Gy), 158 a total dose of 60 Gy (five fractions of 12 Gy) and 30 patients a total dose of 50 Gy (five fractions of 10 Gy) applied on the 80% isodose. Ophthalmologic examinations were performed at baseline and every 3 months in the first 2 years, every 6 months until 5 years, and once a year thereafter until 10 years after radiotherapy. Assessment of visual acuity, routine ophthalmologic examinations, and measurement of tumor base dimension and height using standardized A-scan and B-scan echography were done at each visit. Funduscopy and fluorescein angiography were done when necessary to document tumor response. Results: Median tumor height and volume decreased from 4.8 mm and 270.7 mm{sup 3} at baseline to 2.6 mm and 86.6 mm{sup 3} at the last individual follow-up, respectively (p < 0.001, p < 0.001). Median visual acuity decreased from 0.55 at baseline to hand motion at the last individual follow-up (p < 0.001). Local tumor control was 95.9% after 5 years and 92.6% after 10 years. Thirty-two patients developed metastatic disease, and 22 of these patients died during the follow-up period. Conclusion: Hypofractionated stereotactic photon radiotherapy with 70 to 50 Gy delivered in five fractions in 7 days is sufficient to achieve excellent local tumor control in patients with malignant melanoma of the choroid. Disease outcome and vision are comparable to those achieved with proton beam radiotherapy. Decreasing the

  15. Development of a second generation stereotactic apparatus for linear accelerator radiosurgery.

    PubMed

    Colombo, F; Casentini, L; Pozza, F; Chierego, G; Marchetti, C

    1991-01-01

    Linear accelerator radiosurgery technique is based on a multiple intersecting arc irradiations procedure. The coincidence of the axis of two rotation movements (of gantry and treatment couch) into the isocenter is critical for focusing irradiation. In October 1989, our linear accelerator was changed and the stereotactic apparatus had to be adapted to the new machine. After multiple mechanical tests of the new machine, the stereotactic head frame was fixed to the roller bearing allowing rotation of the couch. The new apparatus is described.

  16. Stereotactic radiosurgery using the gamma knife for acoustic neuromas

    SciTech Connect

    Foote, R.L.; Coffey, R.J.; Swanson, J.W.

    1995-07-15

    The purpose of this investigation was to assess the efficacy and toxicity of stereotactic radiosurgery using the gamma knife for acoustic neuromas. Between January 1990 and January 1993, 36 patients with acoustic neuromas were treated with stereotactic radiosurgery using the gamma knife. The median maximum tumor diameter was 21 mm (range: 6-32 mm). Tumor volumes encompasses within the prescribed isodose line varied from 266 to 8,667 mm{sup 3} (median: 3,135 mm{sup 3}). Tumors {<=} 20 mm in maximum diameter received a dose of 20 Gy to the margin, tumors between 21 and 30 mm received 18 Gy, and tumors > 30 mm received 16 Gy. The dose was prescribed to the 50% isodose line in 31 patients and to the 45%, 55%, 60%, 70%, and 80% isodose line in one patient each. Nine tumors (26%) were smaller, and 26 tumors (74%) were unchanged. No tumor had progressed. The 1- and 2-year actuarial incidences of facial neuropathy were 52.2% and 66.5%, respectively. The 1- and 2-year actuarial incidences of trigeminal neuropathy were 33.7% and 58.9%, respectively. The 1- and 2-year actuarial incidence of facial or trigeminal neuropathy (or both) was 60.8% and 81.7%, respectively. Multivariate analysis revealed that the following were associated with the time of onset or worsening of facial weakness or trigeminal neuropathy: (a) patients < age 65 years, (b) dose to the tumor margin, (c) maximum tumor diameter {>=} 21 mm, (d) use of the 18 mm collimator, and (e) use of > five isocenters. The 1- and 2-year actuarial rates of preservation of useful hearing (Gardner-Robertson class I or II) were 100% and 41.7% {plus_minus} 17.3, respectively. Stereotactic radiosurgery using the gamma knife provides short-term control of acoustic neuromas when a dose of 16 to 20 Gy to the tumor margin is used. Preservation of useful hearing can be accomplished in a significant proportion of patients. 30 refs., 5 tabs.

  17. A round-robin gamma stereotactic radiosurgery dosimetry interinstitution comparison of calibration protocols

    SciTech Connect

    Drzymala, R. E.; Alvarez, P. E.; Bednarz, G.; Bourland, J. D.; DeWerd, L. A.; Ma, L.; Meltsner, S. G.; Neyman, G.; Novotny, J.; Petti, P. L.; Rivard, M. J.; Shiu, A. S.; Goetsch, S. J.

    2015-11-15

    Purpose: Absorbed dose calibration for gamma stereotactic radiosurgery is challenging due to the unique geometric conditions, dosimetry characteristics, and nonstandard field size of these devices. Members of the American Association of Physicists in Medicine (AAPM) Task Group 178 on Gamma Stereotactic Radiosurgery Dosimetry and Quality Assurance have participated in a round-robin exchange of calibrated measurement instrumentation and phantoms exploring two approved and two proposed calibration protocols or formalisms on ten gamma radiosurgery units. The objectives of this study were to benchmark and compare new formalisms to existing calibration methods, while maintaining traceability to U.S. primary dosimetry calibration laboratory standards. Methods: Nine institutions made measurements using ten gamma stereotactic radiosurgery units in three different 160 mm diameter spherical phantoms [acrylonitrile butadiene styrene (ABS) plastic, Solid Water, and liquid water] and in air using a positioning jig. Two calibrated miniature ionization chambers and one calibrated electrometer were circulated for all measurements. Reference dose-rates at the phantom center were determined using the well-established AAPM TG-21 or TG-51 dose calibration protocols and using two proposed dose calibration protocols/formalisms: an in-air protocol and a formalism proposed by the International Atomic Energy Agency (IAEA) working group for small and nonstandard radiation fields. Each institution’s results were normalized to the dose-rate determined at that institution using the TG-21 protocol in the ABS phantom. Results: Percentages of dose-rates within 1.5% of the reference dose-rate (TG-21 + ABS phantom) for the eight chamber-protocol-phantom combinations were the following: 88% for TG-21, 70% for TG-51, 93% for the new IAEA nonstandard-field formalism, and 65% for the new in-air protocol. Averages and standard deviations for dose-rates over all measurements relative to the TG-21 + ABS

  18. Decision Analysis of Stereotactic Radiation Surgery Versus Stereotactic Radiation Surgery and Whole-Brain Radiation Therapy for 1 to 3 Brain Metastases

    SciTech Connect

    Lester-Coll, Nataniel H.; Dosoretz, Arie P.; Yu, James B.

    2014-07-01

    Purpose: Although whole-brain radiation therapy (WBRT) is effective for controlling intracranial disease, it is also associated with neurocognitive side effects. It is unclear whether a theoretically improved quality of life after stereotactic radiation surgery (SRS) alone relative to that after SRS with adjuvant WBRT would justify the omission of WBRT, given the higher risk of intracranial failure. This study compares SRS alone with SRS and WBRT, to evaluate the theoretical benefits of intracranial tumor control with adjuvant WBRT against its possible side effects, using quality-adjusted life expectancy (QALE) as a primary endpoint. Methods and Materials: A Markov decision analysis model was used to compare QALE in a cohort of patients with 1 to 3 brain metastases and Karnofsky performance status of at least 70. Patients were treated with SRS alone or with SRS immediately followed by WBRT. Patients treated with SRS alone underwent surveillance magnetic resonance imaging and received salvage WBRT if they developed intracranial relapse. All patients whose cancer relapsed after WBRT underwent simulation as dying of intracranial progression. Model parameters were estimated from published literature. Results: Treatment with SRS yielded 6.2 quality-adjusted life months (QALMs). The addition of initial WBRT reduced QALE by 1.2 QALMs. On one-way sensitivity analysis, the model was sensitive only to a single parameter, the utility associated with the state of no evidence of disease after SRS alone. At values greater than 0.51, SRS alone was preferred. Conclusions: In general, SRS alone is suggested to have improved quality of life in patients with 1 to 3 brain metastases compared to SRS and immediate WBRT. Our results suggest that immediate treatment with WBRT after SRS can be reserved for patients who would have a poor performance status regardless of treatment. These findings are stable under a wide range of assumptions.

  19. Long-Term Outcomes From a Prospective Trial of Stereotactic Body Radiotherapy for Low-Risk Prostate Cancer

    SciTech Connect

    King, Christopher R.; Brooks, James D.; Gill, Harcharan; Presti, Joseph C.

    2012-02-01

    Purpose: Hypofractionated radiotherapy has an intrinsically different normal tissue and tumor radiobiology. The results of a prospective trial of stereotactic body radiotherapy (SBRT) for prostate cancer with long-term patient-reported toxicity and tumor control rates are presented. Methods and Materials: From 2003 through 2009, 67 patients with clinically localized low-risk prostate cancer were enrolled. Treatment consisted of 36.25 Gy in 5 fractions using SBRT with the CyberKnife as the delivery technology. No patient received hormone therapy. Patient self-reported bladder and rectal toxicities were graded on the Radiation Therapy Oncology Group scale (RTOG). Results: Median follow-up was 2.7 years. There were no grade 4 toxicities. Radiation Therapy Oncology Group Grade 3, 2, and 1 bladder toxicities were seen in 3% (2 patients), 5% (3 patients), and 23% (13 patients) respectively. Dysuria exacerbated by urologic instrumentation accounted for both patients with Grade 3 toxicity. Urinary incontinence, complete obstruction, or persistent hematuria was not observed. Rectal Grade 3, 2, and 1 toxicities were seen in 0, 2% (1 patient), and 12.5% (7 patients), respectively. Persistent rectal bleeding was not observed. Low-grade toxicities were substantially less frequent with QOD vs. QD dose regimen (p = 0.001 for gastrointestinal and p = 0.007 for genitourinary). There were two prostate-specific antigen (PSA), biopsy-proven failures with negative metastatic workup. Median PSA at follow-up was 0.5 {+-} 0.72 ng/mL. The 4-year Kaplan-Meier PSA relapse-free survival was 94% (95% confidence interval, 85%-102%). Conclusion: Significant late bladder and rectal toxicities from SBRT for prostate cancer are infrequent. PSA relapse-free survival compares favorably with other definitive treatments. The current evidence supports consideration of stereotactic body radiotherapy among the therapeutic options for localized prostate cancer.

  20. Gastrointestinal Toxicities With Combined Antiangiogenic and Stereotactic Body Radiation Therapy

    SciTech Connect

    Pollom, Erqi L.; Deng, Lei; Pai, Reetesh K.; Brown, J. Martin; Giaccia, Amato; Loo, Billy W.; Shultz, David B.; Le, Quynh Thu; Koong, Albert C.; Chang, Daniel T.

    2015-07-01

    Combining the latest targeted biologic agents with the most advanced radiation technologies has been an exciting development in the treatment of cancer patients. Stereotactic body radiation therapy (SBRT) is an ablative radiation approach that has become established for the treatment of a variety of malignancies, and it has been increasingly used in combination with biologic agents, including those targeting angiogenesis-specific pathways. Multiple reports have emerged describing unanticipated toxicities arising from the combination of SBRT and angiogenesis-targeting agents, particularly of late luminal gastrointestinal toxicities. In this review, we summarize the literature describing these toxicities, explore the biological mechanism of action of toxicity with the combined use of antiangiogenic therapies, and discuss areas of future research, so that this combination of treatment modalities can continue to be used in broader clinical contexts.

  1. Robotic multimodality stereotactic brain tissue identification: work in progress

    NASA Technical Reports Server (NTRS)

    Andrews, R.; Mah, R.; Galvagni, A.; Guerrero, M.; Papasin, R.; Wallace, M.; Winters, J.

    1997-01-01

    Real-time identification of tissue would improve procedures such as stereotactic brain biopsy (SBX), functional and implantation neurosurgery, and brain tumor excision. To standard SBX equipment has been added: (1) computer-controlled stepper motors to drive the biopsy needle/probe precisely; (2) multiple microprobes to track tissue density, detect blood vessels and changes in blood flow, and distinguish the various tissues being penetrated; (3) neural net learning programs to allow real-time comparisons of current data with a normative data bank; (4) three-dimensional graphic displays to follow the probe as it traverses brain tissue. The probe can differentiate substances such as pig brain, differing consistencies of the 'brain-like' foodstuff tofu, and gels made to simulate brain, as well as detect blood vessels imbedded in these substances. Multimodality probes should improve the safety, efficacy, and diagnostic accuracy of SBX and other neurosurgical procedures.

  2. Stereotactic body radiotherapy: current strategies and future development

    PubMed Central

    2016-01-01

    Stereotactic body radiotherapy (SBRT) has emerged as the standard treatment for medically inoperable early-staged non-small cell lung cancer (NSCLC). The local control rate after SBRT is over 90%. Some forms of tumour motion management and image-guided radiation delivery techniques are the prerequisites for fulfilment of its goal to deliver a high radiation dose to the tumour target without overdosing surrounding normal tissues. In this review, the current strategies of tumour motion management will be discussed, followed by an overview of various image-guided radiotherapy (RT) systems and devices available for clinical practice. Besides medically inoperable stage I NSCLC, SBRT has also been widely adopted for treatment of oligometastasis involving the lungs. Its possible applications in various other cancer illnesses are under extensive exploration. The progress of SBRT is critically technology-dependent. With advancement of technology, the ideal of personalised, effective and yet safe SBRT is already on the horizon. PMID:27606082

  3. Thymic Carcinoma Treated by CyberKnife Stereotactic Body Radiotherapy

    PubMed Central

    Miyazaki, Shinichiro

    2017-01-01

    The standard treatment for advanced thymic carcinoma has not yet been established. Most patients have no symptoms until the advanced stage. Radiation therapy has been used for advanced stage cancer, usually in combination with surgery or chemotherapy; however, the survival rates are 30%-50%. We performed hypofractionated stereotactic radiotherapy with CyberKnife (Accuray, Sunnyvale, CA, USA) for 10 cases of advanced thymic cancer. All cases reached at least partial remission (PR) in two months with progression-free irradiated lesions and minimal radiation-related toxicity. It took only seven to 12 days for each therapy that did not require admission. CyberKnife is beneficial for patients even at the terminal stage. PMID:28367393

  4. MRI-guided stereotactic amygdalohippocampectomy: a single center experience

    PubMed Central

    Vojtěch, Zdeněk; Malíková, Hana; Krámská, Lenka; Liščák, Roman; Vladyka, Vilibald

    2015-01-01

    Background This paper presents our experience of stereotactic radiofrequency amygdalohippocampectomy performed for intractable mesial temporal lobe epilepsy. Methods The article describes the cases of 61 patients who were treated during the period from 2004 to 2010. Mean postoperative follow-up was 5.3 years. Neuropsychological results were obtained for a subset of 31 patients. Results At their last postsurgical visit, 43 (70.5%) patients were Engel class I, six (9.8%) class II, nine (14.8%) class III, and three (4.9%) class IV. The surgery was complicated by four intracranial hematomas. One of them caused acute hydrocephalus and was treated by shunting and resolved without sequelae, while another caused transitory aphasia. The remaining hematomas were asymptomatic. There were two cases of meningitis which required antibiotic treatment. One patient committed suicide due to postoperative depression. After the procedure, we performed open epilepsy surgery and rethermolesions in three and two patients, respectively (8.2%). Patients showed increases in their mean full scale, verbal, and performance intelligence quotient (IQ) scores of 4, 3, and 4 IQ points, respectively (P<0.05). Five (17.2%), four (13.8%), and four (13.3%) patients improved their full scale, verbal, and performance IQ scores, respectively. No significant changes were found in memory performance, with a mean increase of 1, 3, and 0 memory quotient points in global, verbal, and visual memory, respectively (P<0.05). Global memory improved in three (10.3%) patients, verbal memory in one (3.4%), and one patient (3.3%) showed deterioration in visual memory. Conclusion Stereotactic radiofrequency amygdalohippocampectomy offers a safe, effective, and less aggressive treatment modality in cases of well-defined mesial temporal lobe epilepsy. Seizure outcome is comparable with the results of conventional epilepsy surgery and cognitive results could be even better. PMID:25709460

  5. Robotic System for MRI-Guided Stereotactic Neurosurgery

    PubMed Central

    Li, Gang; Cole, Gregory A.; Shang, Weijian; Harrington, Kevin; Camilo, Alex; Pilitsis, Julie G.; Fischer, Gregory S.

    2015-01-01

    Stereotaxy is a neurosurgical technique that can take several hours to reach a specific target, typically utilizing a mechanical frame and guided by preoperative imaging. An error in any one of the numerous steps or deviations of the target anatomy from the preoperative plan such as brain shift (up to 20 mm), may affect the targeting accuracy and thus the treatment effectiveness. Moreover, because the procedure is typically performed through a small burr hole opening in the skull that prevents tissue visualization, the intervention is basically “blind” for the operator with limited means of intraoperative confirmation that may result in reduced accuracy and safety. The presented system is intended to address the clinical needs for enhanced efficiency, accuracy, and safety of image-guided stereotactic neurosurgery for Deep Brain Stimulation (DBS) lead placement. The work describes a magnetic resonance imaging (MRI)-guided, robotically actuated stereotactic neural intervention system for deep brain stimulation procedure, which offers the potential of reducing procedure duration while improving targeting accuracy and enhancing safety. This is achieved through simultaneous robotic manipulation of the instrument and interactively updated in situ MRI guidance that enables visualization of the anatomy and interventional instrument. During simultaneous actuation and imaging, the system has demonstrated less than 15% signal-to-noise ratio (SNR) variation and less than 0.20% geometric distortion artifact without affecting the imaging usability to visualize and guide the procedure. Optical tracking and MRI phantom experiments streamline the clinical workflow of the prototype system, corroborating targeting accuracy with 3-axis root mean square error 1.38 ± 0.45 mm in tip position and 2.03 ± 0.58° in insertion angle. PMID:25376035

  6. Inception of a national multidisciplinary registry for stereotactic radiosurgery.

    PubMed

    Sheehan, Jason P; Kavanagh, Brian D; Asher, Anthony; Harbaugh, Robert E

    2016-01-01

    Stereotactic radiosurgery (SRS) represents a multidisciplinary approach to the delivery of ionizing high-dose radiation to treat a wide variety of disorders. Much of the radiosurgical literature is based upon retrospective single-center studies along with a few randomized controlled clinical trials. More timely and effective evidence is needed to enhance the consistency and quality of and clinical outcomes achieved with SRS. The authors summarize the creation and implementation of a national SRS registry. The American Association of Neurological Surgeons (AANS) through NeuroPoint Alliance, Inc., started a successful registry effort with its lumbar spine initiative. Following a similar approach, the AANS and NeuroPoint Alliance collaborated with corporate partners and the American Society for Radiation Oncology to devise a data dictionary for an SRS registry. Through administrative and financial support from professional societies and corporate partners, a framework for implementation of the registry was created. Initial plans were devised for a 3-year effort encompassing 30 high-volume SRS centers across the country. Device-specific web-based data-extraction platforms were built by the corporate partners. Data uploaders were then used to port the data to a common repository managed by Quintiles, a national and international health care trials company. Audits of the data for completeness and veracity will be undertaken by Quintiles to ensure data fidelity. Data governance and analysis are overseen by an SRS board comprising equal numbers of representatives from the AANS and NeuroPoint Alliance. Over time, quality outcome assessments and post hoc research can be performed to advance the field of SRS. Stereotactic radiosurgery offers a high-technology approach to treating complex intracranial disorders. Improvements in the consistency and quality of care delivered to patients who undergo SRS should be afforded by the national registry effort that is underway.

  7. 10 CFR 35.600 - Use of a sealed source in a remote afterloader unit, teletherapy unit, or gamma stereotactic...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy Units, and..., teletherapy unit, or gamma stereotactic radiosurgery unit. A licensee shall use sealed sources in...

  8. 10 CFR 35.600 - Use of a sealed source in a remote afterloader unit, teletherapy unit, or gamma stereotactic...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy Units, and..., teletherapy unit, or gamma stereotactic radiosurgery unit. A licensee shall use sealed sources in...

  9. WE-E-BRE-02: BEST IN PHYSICS (THERAPY) - Stereotactic Radiotherapy for Renal Sympathetic Ablation for the Treatment of Refractory Hypertension

    SciTech Connect

    Maxim, P; Wheeler, M; Loo, B; Maguire, P

    2014-06-15

    Purpose: To determine the safety and efficacy of stereotactic radiotherapy as a novel treatment for patients with refractory hypertension in a swine model. Uncontrolled hypertension is a significant contributor to morbidity and mortality, substantially increasing the risk of ischemic stroke, ischemic heart disease, and kidney failure. Methods: High-resolution computed tomography (CT) images of anesthetized pigs were acquired and treatment plans for each renal artery and nerve were developed using our clinically implemented treatment planning system. Stereotactic radiotherapy, 40Gy in single fraction was delivered bilaterally to the renal nerves using a state-of-the-art medical linear accelerator under image guidance utilizing dynamic conformal arcs. Dose to nearby critical organs was evaluated by dosevolume histogram analysis and correlated to toxicity data obtained through follow up pathology analysis. The animals were observed for six months with serial measurements of blood pressure, urine analysis, serum laboratories, and overall clinical and behavioral status. Results: All animals survived to the follow-up point without evidence of renal dysfunction (stable serum creatinine), skin changes, or behavioral changes that might suggest animal discomfort. Plasma norepinephrine levels (ng/ml) were followed monthly for 6 months. The average reduction observed was 63%, with the median reduction at 73.5%. Microscopic evaluation 4–6 weeks after treatment showed evidence of damage to the nerves around treated renal arteries. Considerable attenuation in pan neurofilament expression by immunohistochemistry was observed with some vacuolar changes indicative of injury. There was no histological or immunohistochemical evidence of damage to nearby spinal cord or spinal nerve root structures. Conclusion: Our preclinical studies have shown stereotactic radiotherapy to the renal sympathetic plexus to be safe and effective in reducing blood pressure, thus this approach holds great

  10. Hypofractionated Boost to the Dominant Tumor Region With Intensity Modulated Stereotactic Radiotherapy for Prostate Cancer: A Sequential Dose Escalation Pilot Study

    SciTech Connect

    Miralbell, Raymond; Molla, Meritxell; Rouzaud, Michel; Hidalgo, Alberto; Toscas, Jose Ignacio; Lozano, Joan; Sanz, Sergi B.Sc.; Ares, Carmen; Jorcano, Sandra; Linero, Dolors; Escude, Lluis

    2010-09-01

    Purpose: To evaluate the feasibility, tolerability, and preliminary outcomes in patients with prostate cancer treated according to a hypofractionated dose escalation protocol to boost the dominant tumor-bearing region of the prostate. Methods and Materials: After conventional fractionated external radiotherapy to 64 to 64.4Gy, 50 patients with nonmetastatic prostate cancer were treated with an intensity-modulated radiotherapy hypofractionated boost under stereotactic conditions to a reduced prostate volume to the dominant tumor region. A rectal balloon inflated with 60cc of air was used for internal organ immobilization. Five, 8, and 8 patients were sequentially treated with two fractions of 5, 6, or 7Gy, respectively (normalized total dose in 2Gy/fraction [NTD{sub 2Gy}] < 100Gy, low-dose group), whereas 29 patients received two fractions of 8Gy each (NTD{sub 2Gy} > 100Gy, high-dose group). Androgen deprivation was given to 33 patients. Acute and late toxicities were assessed according to the Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer (RTOG/EORTC) scoring system. Results: Two patients presented with Grade 3 acute urinary toxicity. The 5-year probabilities of {>=}Grade 2 late urinary and late low gastrointestinal (GI) toxicity-free survival were 82.2% {+-} 7.4% and 72.2% {+-} 7.6%, respectively. The incidence and severity of acute or late toxicities were not correlated with low- vs. high-dose groups, pelvic irradiation, age, or treatment with or without androgen deprivation. The 5-year biochemical disease-free survival (b-DFS) and disease-specific survival were 98% {+-} 1.9% and 100%, respectively. Conclusion: Intensity-modulated radiotherapy hypofractionated boost dose escalation under stereotactic conditions was feasible, and showed excellent outcomes with acceptable long-term toxicity. This approach may well be considered an alternative to high-dose-rate brachytherapy.

  11. Stereotactic body radiation therapy in hepatocellular carcinoma: Optimal treatment strategies based on liver segmentation and functional hepatic reserve

    PubMed Central

    Wang, Po-Ming; Chung, Na-Na; Hsu, Wei-Chung; Chang, Feng-Ling; Jang, Chin-Jyh; Scorsetti, Marta

    2015-01-01

    Aim To discuss current dosage for stereotactic body radiation therapy (SBRT) in hepatocellular carcinoma (HCC) patients and suggest alternative treatment strategies according to liver segmentation as defined by the Couinaud classification. Background SBRT is a safe and effective alternative treatment for HCC patients who are unable to undergo liver ablation/resection. However, the SBRT fractionation schemes and treatment planning strategies are not well established. Materials and methods In this article, the latest developments and key findings from research studies exploring the efficacy of SBRT fractionation schemes for treatment of HCC are reviewed. Patients’ characteristics, fractionation schemes, treatment outcomes and toxicities were compiled. Special attention was focused on SBRT fractionation approaches that take into consideration liver segmentation according to the Couinaud classification and functional hepatic reserve based on Child–Pugh (CP) liver cirrhosis classification. Results The most common SBRT fractionation schemes for HCC were 3 × 10–20 Gy, 4–6 × 8–10 Gy, and 10 × 5–5.5 Gy. Based on previous SBRT studies, and in consideration of tumor size and CP classification, we proposed 3 × 15–25 Gy for patients with tumor size <3 cm and adequate liver reserve (CP-A score 5), 5 × 10–12 Gy for patients with tumor sizes between 3 and 5 cm or inadequate liver reserve (CP-A score 6), and 10 × 5–5.5 Gy for patients with tumor size >5 cm or CP-B score. Conclusions Treatment schemes in SBRT for HCC vary according to liver segmentation and functional hepatic reserve. Further prospective studies may be necessary to identify the optimal dose of SBRT for HCC. PMID:26696781

  12. Results of stereotactic radiosurgery for patients with imaging defined cavernous sinus meningiomas

    SciTech Connect

    Pollock, Bruce E. . E-mail: pollock.bruce@mayo.edu; Stafford, Scott L.

    2005-08-01

    Introduction: The purpose of this study was to evaluate the efficacy and safety of stereotactic radiosurgery as primary management for patients with imaging defined cavernous sinus meningiomas. Methods: Between 1992 and 2001, 49 patients had radiosurgery for dural-based masses of the cavernous sinus presumed to be meningiomas. The mean patient age was 55.5 years. The mean tumor volume was 10.2 mL; the mean tumor margin dose was 15.9 Gy. The mean follow-up was 58 months (range, 16-144 months). Results: No tumor enlarged after radiosurgery. Twelve of 38 patients (26%) with preexisting diplopia or facial numbness/pain had improvement in cranial nerve function. Five patients (10%) had new (n = 3) or worsened (n = 2) trigeminal dysfunction; 2 of these patients (4%) underwent surgery at 20 and 25 months after radiosurgery despite no evidence of tumor progression. Neither patient improved after partial tumor resection. One patient (2%) developed an oculomotor nerve injury. One patient (2%) had an ischemic stroke related to occlusion of the cavernous segment of the internal carotid artery. Event-free survival was 98%, 85%, and 80% at 1, 3, and 7 years after radiosurgery, respectively. Univariate analysis of patient and dosimetric factors found no analyzed factor correlated with postradiosurgical morbidity. Conclusions: Radiosurgery was an effective primary management strategy for patients with an imaging defined cavernous sinus meningioma. Except in situations of symptomatic mass effect, unusual clinical presentation, or atypical imaging features, surgery to confirm the histologic diagnosis is unlikely to provide clinical benefit.

  13. Characteristics of a dedicated linear accelerator-based stereotactic radiosurgery-radiotherapy unit.

    PubMed

    Das, I J; Downes, M B; Corn, B W; Curran, W J; Werner-Wasik, M; Andrews, D W

    1996-01-01

    A stereotactic radiosurgery and radiotherapy (SRS/SRT) system on a dedicated Varian Clinac-600SR linear accelerator with Brown-Roberts-Wells and Gill-Thomas-Cosman relocatable frames along with the Radionics (RSA) planning system is evaluated. The Clinac-600SR has a single 6-MV beam with the same beam characteristics as that of the mother unit, the Clinac-600C. The primary collimator is a fixed cone projecting to a 10-cm diameter at isocenter. The secondary collimator is a heavily shielded cylindrical collimator attached to the face plate of the primary collimator. The tertiary collimation consists of the actual treatment cones. The cone sizes vary from 12.5 to 40.0 mm diameter. The mechanical stability of the entire system was verified. The variations in isocenter position with table, gantry, and collimator rotation were found to be < 0.5 mm with a compounded accuracy of < or = 1.0 mm. The radiation leakage under the cones was < 1% measured at a depth of 5 cm in a phantom. The beam profiles of all cones in the x and y directions were within +/- 0.5 mm and match with the physical size of the cone. The dosimetric data such as tissue maximum ratio, off-axis ratio, and cone factor were taken using film, diamond detector, and ion chambers. The mechanical and dosimetric characteristics including dose linearity of this unit are presented and found to be suitable for SRS/SRT. The difficulty in absolute dose measurement for small cone is discussed.

  14. Stereotactic Ablative Radiosurgery for Locally Advanced or Recurrent Skull Base Malignancies with Prior External Beam Radiation Therapy

    PubMed Central

    Xu, Karen M.; Quan, Kimmen; Clump, David A.; Ferris, Robert L.; Heron, Dwight E.

    2015-01-01

    Purpose: Stereotactic ablative radiotherapy (SABR) is an attractive modality to treat malignancies invading the skull base as it can deliver a highly conformal dose with minimal toxicity. However, variation exists in the prescribed dose and fractionation. The purpose of our study is to examine the local control, survival, and toxicities in SABR for the treatment of previously irradiated malignant skull base tumors. Materials and methods: A total of 31 patients and 40 locally advanced or recurrent head and neck malignancies involving the skull base treated with a common SABR regimen, which delivers a radiation dose of 44 Gy in 5 fractions from January 1st, 2004 to December 31st, 2013, were retrospectively reviewed. The local control rate (LC), progression-free survival rate, overall survival (OS) rate, and toxicities were reported. Results: The median follow-up time of all patients was 11.4 months (range: 0.6–67.2 months). The median tumor volume was 27 cm3 (range: 2.4–205 cm3). All patients received prior external beam radiation therapy with a median radiation dose of 64 Gy (range: 24–75.6 Gy) delivered in 12–42 fractions. Twenty patients had surgeries prior to SABR. Nineteen patients received chemotherapy. Specifically, eight patients received concurrent cetuximab (Erbitux™) with SABR. The median time-to-progression (TTP) was 3.3 months (range: 0–16.9 months). For the 29 patients (93.5%) who died, the median time from the end of first SABR to death was 10.3 months (range: 0.5–41.4 months). The estimated 1-year OS rate was 35%. The estimated 2-year OS rate was 12%. Treatment was well-tolerated without grade 4 or 5 treatment-related toxicities. Conclusion: Stereotactic ablative radiotherapy has been shown to achieve low toxicities in locally advanced or recurrent, previously irradiated head and neck malignancies invading the skull base. PMID:25853093

  15. Intrafraction Variation of Mean Tumor Position During Image-Guided Hypofractionated Stereotactic Body Radiotherapy for Lung Cancer

    SciTech Connect

    Shah, Chirag; Grills, Inga S.; Kestin, Larry L.; McGrath, Samuel; Ye Hong; Martin, Shannon K.; Yan Di

    2012-04-01

    Purpose: Prolonged delivery times during daily cone-beam computed tomography (CBCT)-guided lung stereotactic body radiotherapy (SBRT) introduce concerns regarding intrafraction variation (IFV) of the mean target position (MTP). The purpose of this study was to evaluate the magnitude of the IFV-MTP and to assess target margins required to compensate for IFV and postonline CBCT correction residuals. Patient, treatment, and tumor characteristics were analyzed with respect to their impact on IFV-MTP. Methods and Materials: A total of 126 patients with 140 tumors underwent 659 fractions of lung SBRT. Dose prescribed was 48 or 60 Gy in 12 Gy fractions. Translational target position correction of the MTP was performed via onboard CBCT. IFV-MTP was measured as the difference in MTP between the postcorrection CBCT and the posttreatment CBCT excluding residual error. Results: IFV-MTP was 0.2 {+-} 1.8 mm, 0.1 {+-} 1.9 mm, and 0.01 {+-} 1.5 mm in the craniocaudal, anteroposterior, and mediolateral dimensions and the IFV-MTP vector was 2.3 {+-} 2.1 mm. Treatment time and excursion were found to be significant predictors of IFV-MTP. An IFV-MTP vector greater than 2 and 5 mm was seen in 40.8% and 7.2% of fractions, respectively. IFV-MTP greater than 2 mm was seen in heavier patients with larger excursions and longer treatment times. Significant differences in IFV-MTP were seen between immobilization devices. The stereotactic frame immobilization device was found to be significantly less likely to have an IFV-MTP vector greater than 2 mm compared with the alpha cradle, BodyFIX, and hybrid immobilization devices. Conclusions: Treatment time and respiratory excursion are significantly associated with IFV-MTP. Significant differences in IFV-MTP were found between immobilization devices. Target margins for IFV-MTP plus post-correction residuals are dependent on immobilization device with 5-mm uniform margins being acceptable for the frame immobilization device.

  16. Residual {sup 18}F-FDG-PET Uptake 12 Weeks After Stereotactic Ablative Radiotherapy for Stage I Non-Small-Cell Lung Cancer Predicts Local Control

    SciTech Connect

    Bollineni, Vikram Rao; Widder, Joachim; Pruim, Jan; Langendijk, Johannes A.; Wiegman, Erwin M.

    2012-07-15

    Purpose: To investigate the prognostic value of [{sup 18}F]fluorodeoxyglucose positron emission tomography (FDG-PET) uptake at 12 weeks after stereotactic ablative radiotherapy (SABR) for stage I non-small-cell lung cancer (NSCLC). Methods and Materials: From November 2006 to February 2010, 132 medically inoperable patients with proven Stage I NSCLC or FDG-PET-positive primary lung tumors were analyzed retrospectively. SABR consisted of 60 Gy delivered in 3 to 8 fractions. Maximum standardized uptake value (SUV{sub max}) of the treated lesion was assessed 12 weeks after SABR, using FDG-PET. Patients were subsequently followed at regular intervals using computed tomography (CT) scans. Association between post-SABR SUV{sub max} and local control (LC), mediastinal failure, distant failure, overall survival (OS), and disease-specific survival (DSS) was examined. Results: Median follow-up time was 17 months (range, 3-40 months). Median lesion size was 25 mm (range, 9-70 mm). There were 6 local failures: 15 mediastinal failures, 15 distant failures, 13 disease-related deaths, and 16 deaths from intercurrent diseases. Glucose corrected post-SABR median SUV{sub max} was 3.0 (range, 0.55-14.50). Using SUV{sub max} 5.0 as a cutoff, the 2-year LC was 80% versus 97.7% for high versus low SUV{sub max}, yielding an adjusted subhazard ratio (SHR) for high post-SABR SUV{sub max} of 7.3 (95% confidence interval [CI], 1.4-38.5; p = 0.019). Two-year DSS rates were 74% versus 91%, respectively, for high and low SUV{sub max} values (SHR, 2.2; 95% CI, 0.8-6.3; p = 0.113). Two-year OS was 62% versus 81% (hazard ratio [HR], 1.6; 95% CI, 0.7-3.7; p = 0.268). Conclusions: Residual FDG uptake (SUV{sub max} {>=}5.0) 12 weeks after SABR signifies increased risk of local failure. A single FDG-PET scan at 12 weeks could be used to tailor further follow-up according to the risk of failure, especially in patients potentially eligible for salvage surgery.

  17. Stereotactic body radiation therapy planning with duodenal sparing using volumetric-modulated arc therapy vs intensity-modulated radiation therapy in locally advanced pancreatic cancer: A dosimetric analysis

    SciTech Connect

    Kumar, Rachit; Wild, Aaron T.; Ziegler, Mark A.; Hooker, Ted K.; Dah, Samson D.; Tran, Phuoc T.; Kang, Jun; Smith, Koren; Zeng, Jing; Pawlik, Timothy M.; Tryggestad, Erik; Ford, Eric; Herman, Joseph M.

    2013-10-01

    Stereotactic body radiation therapy (SBRT) achieves excellent local control for locally advanced pancreatic cancer (LAPC), but may increase late duodenal toxicity. Volumetric-modulated arc therapy (VMAT) delivers intensity-modulated radiation therapy (IMRT) with a rotating gantry rather than multiple fixed beams. This study dosimetrically evaluates the feasibility of implementing duodenal constraints for SBRT using VMAT vs IMRT. Non–duodenal sparing (NS) and duodenal-sparing (DS) VMAT and IMRT plans delivering 25 Gy in 1 fraction were generated for 15 patients with LAPC. DS plans were constrained to duodenal D{sub max} of<30 Gy at any point. VMAT used 1 360° coplanar arc with 4° spacing between control points, whereas IMRT used 9 coplanar beams with fixed gantry positions at 40° angles. Dosimetric parameters for target volumes and organs at risk were compared for DS planning vs NS planning and VMAT vs IMRT using paired-sample Wilcoxon signed rank tests. Both DS VMAT and DS IMRT achieved significantly reduced duodenal D{sub mean}, D{sub max}, D{sub 1cc}, D{sub 4%}, and V{sub 20} {sub Gy} compared with NS plans (all p≤0.002). DS constraints compromised target coverage for IMRT as demonstrated by reduced V{sub 95%} (p = 0.01) and D{sub mean} (p = 0.02), but not for VMAT. DS constraints resulted in increased dose to right kidney, spinal cord, stomach, and liver for VMAT. Direct comparison of DS VMAT and DS IMRT revealed that VMAT was superior in sparing the left kidney (p<0.001) and the spinal cord (p<0.001), whereas IMRT was superior in sparing the stomach (p = 0.05) and the liver (p = 0.003). DS VMAT required 21% fewer monitor units (p<0.001) and delivered treatment 2.4 minutes faster (p<0.001) than DS IMRT. Implementing DS constraints during SBRT planning for LAPC can significantly reduce duodenal point or volumetric dose parameters for both VMAT and IMRT. The primary consequence of implementing DS constraints for VMAT is increased dose to other organs at

  18. Study of 201 Non-Small Cell Lung Cancer Patients Given Stereotactic Ablative Radiation Therapy Shows Local Control Dependence on Dose Calculation Algorithm

    SciTech Connect

    Latifi, Kujtim; Oliver, Jasmine; Baker, Ryan; Dilling, Thomas J.; Stevens, Craig W.; Kim, Jongphil; Yue, Binglin; DeMarco, MaryLou; Zhang, Geoffrey G.; Moros, Eduardo G.; Feygelman, Vladimir

    2014-04-01

    Purpose: Pencil beam (PB) and collapsed cone convolution (CCC) dose calculation algorithms differ significantly when used in the thorax. However, such differences have seldom been previously directly correlated with outcomes of lung stereotactic ablative body radiation (SABR). Methods and Materials: Data for 201 non-small cell lung cancer patients treated with SABR were analyzed retrospectively. All patients were treated with 50 Gy in 5 fractions of 10 Gy each. The radiation prescription mandated that 95% of the planning target volume (PTV) receive the prescribed dose. One hundred sixteen patients were planned with BrainLab treatment planning software (TPS) with the PB algorithm and treated on a Novalis unit. The other 85 were planned on the Pinnacle TPS with the CCC algorithm and treated on a Varian linac. Treatment planning objectives were numerically identical for both groups. The median follow-up times were 24 and 17 months for the PB and CCC groups, respectively. The primary endpoint was local/marginal control of the irradiated lesion. Gray's competing risk method was used to determine the statistical differences in local/marginal control rates between the PB and CCC groups. Results: Twenty-five patients planned with PB and 4 patients planned with the CCC algorithms to the same nominal doses experienced local recurrence. There was a statistically significant difference in recurrence rates between the PB and CCC groups (hazard ratio 3.4 [95% confidence interval: 1.18-9.83], Gray's test P=.019). The differences (Δ) between the 2 algorithms for target coverage were as follows: ΔD99{sub GITV} = 7.4 Gy, ΔD99{sub PTV} = 10.4 Gy, ΔV90{sub GITV} = 13.7%, ΔV90{sub PTV} = 37.6%, ΔD95{sub PTV} = 9.8 Gy, and ΔD{sub ISO} = 3.4 Gy. GITV = gross internal tumor volume. Conclusions: Local control in patients receiving who were planned to the same nominal dose with PB and CCC algorithms were statistically significantly different. Possible alternative

  19. A Prospective Phase 2 Trial of Reirradiation With Stereotactic Body Radiation Therapy Plus Cetuximab in Patients With Previously Irradiated Recurrent Squamous Cell Carcinoma of the Head and Neck

    SciTech Connect

    Vargo, John A.; Ferris, Robert L.; Ohr, James; Clump, David A.; Davis, Kara S.; Duvvuri, Umamaheswar; Kim, Seungwon; Johnson, Jonas T.; Bauman, Julie E.; Gibson, Michael K.; Branstetter, Barton F.; Heron, Dwight E.

    2015-03-01

    Purpose: Salvage options for unresectable locally recurrent, previously irradiated squamous cell carcinoma of the head and neck (rSCCHN) are limited. Although the addition of reirradiation may improve outcomes compared to chemotherapy alone, significant toxicities limit salvage reirradiation strategies, leading to suboptimal outcomes. We therefore designed a phase 2 protocol to evaluate the efficacy of stereotactic body radiation therapy (SBRT) plus cetuximab for rSCCHN. Methods and Materials: From July 2007 to March 2013, 50 patients >18 years of age with inoperable locoregionally confined rSCCHN within a previously irradiated field receiving ≥60 Gy, with a Zubrod performance status of 0 to 2, and normal hepatic and renal function were enrolled. Patients received concurrent cetuximab (400 mg/m{sup 2} on day −7 and then 250 mg/m{sup 2} on days 0 and +8) plus SBRT (40-44 Gy in 5 fractions on alternating days over 1-2 weeks). Primary endpoints were 1-year locoregional progression-free survival and National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0 graded toxicity. Results: Median follow-up for surviving patients was 18 months (range: 10-70). The 1-year local PFS rate was 60% (95% confidence interval [CI]: 44%-75%), locoregional PFS was 37% (95% CI: 23%-53%), distant PFS was 71% (95% CI: 54%-85%), and PFS was 33% (95% CI: 20%-49%). The median overall survival was 10 months (95% CI: 7-16), with a 1-year overall survival of 40% (95% CI: 26%-54%). At last follow-up, 69% died of disease, 4% died with disease, 15% died without progression, 10% were alive without progression, and 2% were alive with progression. Acute and late grade 3 toxicity was observed in 6% of patients respectively. Conclusions: SBRT with concurrent cetuximab appears to be a safe salvage treatment for rSCCHN of short overall treatment time.

  20. GammaPod—A new device dedicated for stereotactic radiotherapy of breast cancer

    PubMed Central

    Yu, Cedric X.; Shao, Xinyu; Zhang, Jin; Regine, William; Zheng, Mike; Yu, Ying S.; Deng, Jianchun; Duan, Zhengcheng

    2013-01-01

    Purpose: This paper introduces a new external beam radiotherapy device named GammaPod that is dedicated for stereotactic radiotherapy of breast cancer. Methods: The design goal of the GammaPod as a dedicated system for treating breast cancer is the ability to deliver ablative doses with sharp gradients under stereotactic image guidance. Stereotactic localization of the breast is achieved by a vacuum-assisted breast immobilization cup with built-in stereotactic frame. Highly focused radiation is achieved at the isocenter due to the cross-firing from 36 radiation arcs generated by rotating 36 individual Cobalt-60 beams. The dedicated treatment planning system optimizes an optimal path of the focal spot using an optimization algorithm borrowed from computational geometry such that the target can be covered by 90%–95% of the prescription dose and the doses to surrounding tissues are minimized. The treatment plan is intended to be delivered with continuous motion of the treatment couch. In this paper the authors described in detail the gamma radiation unit, stereotactic localization of the breast, and the treatment planning system of the GammaPod system. Results: A prototype GammaPod system was installed at University of Maryland Medical Center and has gone through a thorough functional, geometric, and dosimetric testing. The mechanical and functional performances of the system all meet the functional specifications. Conclusions: An image-guided breast stereotactic radiotherapy device, named GammaPod, has been developed to deliver highly focused and localized doses to a target in the breast under stereotactic image guidance. It is envisioned that the GammaPod technology has the potential to significantly shorten radiation treatments and even eliminate surgery by ablating the tumor and sterilizing the tumor bed simultaneously. PMID:23635251

  1. GammaPod-A new device dedicated for stereotactic radiotherapy of breast cancer

    SciTech Connect

    Yu, Cedric X.; Shao Xinyu; Deng Jianchun; Duan Zhengcheng; Zhang Jin; Zheng, Mike; Yu, Ying S.; Regine, William

    2013-05-15

    Purpose: This paper introduces a new external beam radiotherapy device named GammaPod that is dedicated for stereotactic radiotherapy of breast cancer. Methods: The design goal of the GammaPod as a dedicated system for treating breast cancer is the ability to deliver ablative doses with sharp gradients under stereotactic image guidance. Stereotactic localization of the breast is achieved by a vacuum-assisted breast immobilization cup with built-in stereotactic frame. Highly focused radiation is achieved at the isocenter due to the cross-firing from 36 radiation arcs generated by rotating 36 individual Cobalt-60 beams. The dedicated treatment planning system optimizes an optimal path of the focal spot using an optimization algorithm borrowed from computational geometry such that the target can be covered by 90%-95% of the prescription dose and the doses to surrounding tissues are minimized. The treatment plan is intended to be delivered with continuous motion of the treatment couch. In this paper the authors described in detail the gamma radiation unit, stereotactic localization of the breast, and the treatment planning system of the GammaPod system. Results: A prototype GammaPod system was installed at University of Maryland Medical Center and has gone through a thorough functional, geometric, and dosimetric testing. The mechanical and functional performances of the system all meet the functional specifications. Conclusions: An image-guided breast stereotactic radiotherapy device, named GammaPod, has been developed to deliver highly focused and localized doses to a target in the breast under stereotactic image guidance. It is envisioned that the GammaPod technology has the potential to significantly shorten radiation treatments and even eliminate surgery by ablating the tumor and sterilizing the tumor bed simultaneously.

  2. Stereotactic Body Radiotherapy Is Effective Salvage Therapy for Patients With Prior Radiation of Spinal Metastases

    SciTech Connect

    Sahgal, Arjun Ames, Christopher; Chou, Dean; Ma Lijun; Huang, Kim; Xu Wei; Chin, Cynthia; Weinberg, Vivan; Chuang, Cynthia; Weinstein, Phillip; Larson, David A.

    2009-07-01

    Purpose: To provide actuarial outcomes and dosimetric data for spinal/paraspinal metastases, with and without prior radiation, treated with stereotactic body radiotherapy (SBRT). Methods and Materials: A total of 39 consecutive patients (60 metastases) were treated with SBRT between April 2003 and August 2006 and retrospectively reviewed. In all, 23 of 60 tumors had no previous radiation (unirradiated) and 37/60 tumors had previous irradiation (reirradiated). Of 37 reirradiated tumors, 31 were treated for 'salvage' given image-based tumor progression. Local failure was defined as progression by imaging and/or clinically. Results: At last follow-up, 19 patients were deceased. Median patient survival time measured was 21 months (95% CI = 8-27 months), and the 2-year survival probability was 45%. The median total dose prescribed was 24 Gy in three fractions prescribed to the 67% and 60% isodose for the unirradiated and reirradiated cohorts, respectively. The median tumor follow-up for the unirradiated and reirradiated group was 9 months (range, 1-26) and 7 months (range, 1-48) respectively. Eight of 60 tumors have progressed, and the 1- and 2-year progression-free probability (PFP) was 85% and 69%, respectively. For the salvage group the 1 year PFP was 96%. There was no significant difference in overall survival or PFP between the salvage reirradiated vs. all other tumors treated (p = 0.08 and p = 0.31, respectively). In six of eight failures the minimum distance from the tumor to the thecal sac was {<=}1 mm. Of 60 tumors treated, 39 have {>=}6 months follow-up and no radiation-induced myelopathy or radiculopathy has occurred. Conclusion: Spine SBRT has shown preliminary efficacy and safety in patients with image-based progression of previously irradiated metastases.

  3. Induction Gemcitabine and Stereotactic Body Radiotherapy for Locally Advanced Nonmetastatic Pancreas Cancer

    SciTech Connect

    Mahadevan, Anand; Miksad, Rebecca; Goldstein, Michael; Sullivan, Ryan; Bullock, Andrea; Buchbinder, Elizabeth; Pleskow, Douglas; Sawhney, Mandeep; Kent, Tara; Vollmer, Charles; Callery, Mark

    2011-11-15

    Purpose: Stereotactic body radiotherapy (SBRT) has been used successfully to treat patients with locally advanced pancreas cancer. However, many patients develop metastatic disease soon after diagnosis and may receive little benefit from such therapy. We therefore retrospectively analyzed a planned strategy of initial chemotherapy with restaging and then treatment for those patients with no evidence of metastatic progression with SBRT. Methods and Materials: Forty-seven patients received gemcitabine (1,000 mg/m{sup 2} per week for 3 weeks then 1 week off) until tolerance, at least six cycles, or progression. Patients without metastases after two cycles were treated with SBRT (tolerance-based dose of 24-36 Gy in 3 fractions) between the third and fourth cycles without interrupting the chemotherapy cycles. Results: Eight of the 47 patients (17%) were found to have metastatic disease after two cycles of gemcitabine; the remaining 39 patients received SBRT. The median follow-up for survivors was 21 months (range, 6-36 months). The median overall survival for all patients who received SBRT was 20 months, and the median progression-free survival was 15 months. The local control rate was 85% (33 of 39 patients); and 54% of patients (21 of 39) developed metastases. Late Grade III toxicities such as GI bleeding and obstruction were observed in 9% (3/39) of patients. Conclusion: For patients with locally advanced pancreas cancer, this strategy uses local therapy for those who are most likely to benefit from it and spares those patients with early metastatic progression from treatment. SBRT delivers such local therapy safely with minimal interruption to systemic chemotherapy, thereby potentially improving the outcome in these patients.

  4. Dosimetric Impact of Interplay Effect on RapidArc Lung Stereotactic Treatment Delivery

    SciTech Connect

    Ong, Chin Loon; Verbakel, Wilko F.A.R.; Cuijpers, Johan P.; Slotman, Ben J.; Senan, Suresh

    2011-01-01

    Purpose: Volumetric modulated arc therapy (RapidArc; Varian Medical Systems, Palo Alto, CA) allows fast delivery of stereotactic radiotherapy for Stage I lung tumors. We investigated discrepancies between the calculated and delivered dose distributions, as well as the dosimetric impact of leaf interplay with breathing-induced tumor motion. Methods and Materials: In 20 consecutive patients with Stage I lung cancer who completed RapidArc delivery, 15 had tumor motion exceeding 5 mm on four-dimensional computed tomography scan. Static and dynamic measurements were performed with Gafchromic EBT film (International Specialty Products Inc., Wayne, NJ) in a Quasar motion phantom (Modus Medical Devices, London, Ontario, Canada). Static measurements were compared with calculated dose distributions, and dynamic measurements were compared with the convolution of static measurements with sinusoidal motion patterns. Besides clinical treatment plans, additional cases were optimized to create excessive multileaf collimator modulation and delivered on the phantom with peak-to-peak motions of up to 25 mm. {gamma} Analysis with a 3% dose difference and 2- or 1-mm distance to agreement was used to evaluate the accuracy of delivery and the dosimetric impact of the interplay effect. Results: In static mode film dosimetry of the two-arc delivery in the phantom showed that, on average, fewer than 3% of measurements had {gamma} greater than 1. Dynamic measurements of clinical plans showed a high degree of agreement with the convolutions: for double-arc plans, 99.5% met the {gamma} criterion. The degree of agreement was 98.5% for the plans with excessive multileaf collimator modulations and 25 mm of motion. Conclusions: Film dosimetry shows that RapidArc accurately delivers the calculated dose distribution and that interplay between leaves and tumor motion is not significant for single-fraction treatments when RapidArc is delivered with two different arcs.

  5. Sexual Function After Stereotactic Body Radiotherapy for Prostate Cancer: Results of a Prospective Clinical Trial

    SciTech Connect

    Wiegner, Ellen A.; King, Christopher R.

    2010-10-01

    Purpose: To study the sexual quality of life for prostate cancer patients after stereotactic body radiotherapy (SBRT). Methods and Materials: Using the Expanded Prostate Cancer Index Composite (EPIC)-validated quality-of-life questionnaire, the sexual function of 32 consecutive patients who received prostate SBRT in a prospective Phase II clinical trial were analyzed at baseline, and at median times of 4, 12, 20, and 50 months after treatment. SBRT consisted of 36.25 Gy in five fractions of 7.25 Gy using the Cyberknife. No androgen deprivation therapy was given. The use of erectile dysfunction (ED) medications was monitored. A comprehensive literature review for radiotherapy-alone modalities based on patient self-reported questionnaires served as historical comparison. Results: Median age at treatment was 67.5 years, and median follow-up was 35.5 months (minimum 12 months). The mean EPIC sexual domain summary score, sexual function score, and sexual bother score decreased by 45%, 49%, and 25% respectively at 50 months follow-up. These differences reached clinical relevance by 20 months after treatment. Baseline ED rate was 38% and increased to 71% after treatment (p = 0.024). Use of ED medications was 3% at baseline and progressed to 25%. For patients aged <70 years at follow-up, 60% maintained satisfactory erectile function after treatment compared with only 12% aged {>=}70 years (p = 0.008). Penile bulb dose was not associated with ED. Conclusions: The rates of ED after treatment appear comparable to those reported for other modalities of radiotherapy. Given the modest size of this study and the uncertainties in the physiology of radiotherapy-related ED, these results merit further investigations.

  6. Dosimetric comparison of volumetric modulated arc therapy with robotic stereotactic radiation therapy in hepatocellular carcinoma

    PubMed Central

    Paik, Eun Kyung; Choi, Chul Won; Jang, Won Il; Lee, Sung Hyun; Choi, Sang Hyoun; Kim, Kum Bae; Lee, Dong Han

    2015-01-01

    Purpose To compare volumetric modulated arc therapy of RapidArc with robotic stereotactic body radiation therapy (SBRT) of CyberKnife in the planning and delivery of SBRT for hepatocellular carcinoma (HCC) treatment by analyzing dosimetric parameters. Materials and Methods Two radiation treatment plans were generated for 29 HCC patients, one using Eclipse for the RapidArc plan and the other using Multiplan for the CyberKnife plan. The prescription dose was 60 Gy in 3 fractions. The dosimetric parameters of planning target volume (PTV) coverage and normal tissue sparing in the RapidArc and the CyberKnife plans were analyzed. Results The conformity index was 1.05 ± 0.02 for the CyberKnife plan, and 1.13 ± 0.10 for the RapidArc plan. The homogeneity index was 1.23 ± 0.01 for the CyberKnife plan, and 1.10 ± 0.03 for the RapidArc plan. For the normal liver, there were significant differences between the two plans in the low-dose regions of V1 and V3. The normalized volumes of V60 for the normal liver in the RapidArc plan were drastically increased when the mean dose of the PTVs in RapidArc plan is equivalent to the mean dose of the PTVs in the CyberKnife plan. Conclusion CyberKnife plans show greater dose conformity, especially in small-sized tumors, while RapidArc plans show good dosimetric distribution of low dose sparing in the normal liver and body. PMID:26484307

  7. Prognostic Factors in Stereotactic Body Radiotherapy for Non-Small-Cell Lung Cancer

    SciTech Connect

    Matsuo, Yukinori; Shibuya, Keiko; Nagata, Yasushi; Takayama, Kenji; Norihisa, Yoshiki; Mizowaki, Takashi; Narabayashi, Masaru; Sakanaka, Katsuyuki; Hiraoka, Masahiro

    2011-03-15

    Purpose: To investigate the factors that influence clinical outcomes after stereotactic body radiotherapy (SBRT) for non-small-cell lung cancer (NSCLC). Methods and Materials: A total of 101 consecutive patients who underwent SBRT with 48 Gy in 4 fractions for histologically confirmed Stage I NSCLC were enrolled in this study. Factors including age, maximal tumor diameter, sex, performance status, operability, histology, and overall treatment time were evaluated with regard to local progression (LP), disease progression (DP), and overall survival (OS) using the Cox proportional hazards model. Prognostic models were built with recursive partitioning analysis. Results: Three-year OS was 58.6% with a median follow-up of 31.4 months. Cumulative incidence rates of LP and DP were 13.2% and 40.8% at 3 years, respectively. Multivariate analysis demonstrated that tumor diameter was a significant factor in all endpoints of LP, DP, and OS. Other significant factors were age in DP and sex in OS. Recursive partitioning analysis indicated a condition for good prognosis (Class I) as follows: female or T1a (tumor diameter {<=}20 mm). When the remaining male patients with T1b-2a (>20 mm) were defined as Class II, 3-year LP, DP, and OS were 6.8%, 23.6%, and 69.9% in recursive partitioning analysis Class I, respectively, whereas these values were 19.9%, 58.3%, and 47.1% in Class II. The differences between the classes were statistically significant. Conclusions: Tumor diameter and sex were the most significant factors in SBRT for NSCLC. T1a or female patients had good prognosis.

  8. Generalizable Class Solutions for Treatment Planning of Spinal Stereotactic Body Radiation Therapy

    SciTech Connect

    Weksberg, David C.; Palmer, Matthew B.; Vu, Khoi N.; Rebueno, Neal C.; Sharp, Hadley J.; Luo, Dershan; Yang, James N.; Shiu, Almon S.; Rhines, Laurence D.; McAleer, Mary Frances; Brown, Paul D.; Chang, Eric L.

    2012-11-01

    Purpose: Spinal stereotactic body radiation therapy (SBRT) continues to emerge as an effective therapeutic approach to spinal metastases; however, treatment planning and delivery remain resource intensive at many centers, which may hamper efficient implementation in clinical practice. We sought to develop a generalizable class solution approach for spinal SBRT treatment planning that would allow confidence that a given plan provides optimal target coverage, reduce integral dose, and maximize planning efficiency. Methods and Materials: We examined 91 patients treated with spinal SBRT at our institution. Treatment plans were categorized by lesion location, clinical target volume (CTV) configuration, and dose fractionation scheme, and then analyzed to determine the technically achievable dose gradient. A radial cord expansion was subtracted from the CTV to yield a planning CTV (pCTV) construct for plan evaluation. We reviewed the treatment plans with respect to target coverage, dose gradient, integral dose, conformality, and maximum cord dose to select the best plans and develop a set of class solutions. Results: The class solution technique generated plans that maintained target coverage and improved conformality (1.2-fold increase in the 95% van't Riet Conformation Number describing the conformality of a reference dose to the target) while reducing normal tissue integral dose (1.3-fold decrease in the volume receiving 4 Gy (V{sub 4Gy}) and machine output (19% monitor unit (MU) reduction). In trials of planning efficiency, the class solution technique reduced treatment planning time by 30% to 60% and MUs required by {approx}20%: an effect independent of prior planning experience. Conclusions: We have developed a set of class solutions for spinal SBRT that incorporate a pCTV metric for plan evaluation while yielding dosimetrically superior treatment plans with increased planning efficiency. Our technique thus allows for efficient, reproducible, and high-quality spinal

  9. Stereotactic Radiosurgery for Treatment of Spinal Metastases Recurring in Close Proximity to Previously Irradiated Spinal Cord

    SciTech Connect

    Choi, Clara Y.H.; Adler, John R.; Gibbs, Iris C.; Chang, Steven D.; Jackson, Paul S.; Minn, A. Yuriko; Lieberson, Robert E.; Soltys, Scott G.

    2010-10-01

    Purpose: As the spinal cord tolerance often precludes reirradiation with conventional techniques, local recurrence within a previously irradiated field presents a treatment challenge. Methods and Materials: We retrospectively reviewed 51 lesions in 42 patients treated from 2002 to 2008 whose spinal metastases recurred in a previous radiation field (median previous spinal cord dose of 40 Gy) and were subsequently treated with stereotactic radiosurgery (SRS). Results: SRS was delivered to a median marginal dose of 20 Gy (range, 10-30 Gy) in 1-5 fractions (median, 2), targeting a median tumor volume of 10.3 cm{sup 3} (range, 0.2-128.6 cm{sup 3}). Converting the SRS regimens with the linear quadratic model ({alpha}/{beta} = 3), the median spinal cord maximum single-session equivalent dose (SSED) was 12.1 Gy{sub 3} (range, 4.7-19.3 Gy{sub 3}). With a median follow-up of 7 months (range, 2-47 months), the Kaplan-Meier local control and overall survival rates at 6/12 months were 87%/73% and 81%/68%, respectively. A time to retreatment of {<=}12 months and the combination of time to retreatment of {<=}12 months with an SSED of <15 Gy{sub 10} were significant predictors of local failure on univariate and multivariate analyses. In patients with a retreatment interval of <12 months, 6/12 month local control rates were 88%/58%, with a SSED of >15 Gy{sub 10}, compared to 45%/0% with <15 Gy{sub 10}, respectively. One patient (2%) experienced Grade 4 neurotoxicity. Conclusion: SRS is safe and effective in the treatment of spinal metastases recurring in previously irradiated fields. Tumor recurrence within 12 months may correlate with biologic aggressiveness and require higher SRS doses (SSED >15 Gy{sub 10}). Further research is needed to define the partial volume retreatment tolerance of the spinal cord and the optimal target dose.

  10. Stereotactic Body Radiotherapy for Localized Prostate Cancer: Interim Results of a Prospective Phase II Clinical Trial

    SciTech Connect

    King, Christopher R. Brooks, James D.; Gill, Harcharan; Pawlicki, Todd; Cotrutz, Cristian; Presti, Joseph C.

    2009-03-15

    Purpose: The radiobiology of prostate cancer favors a hypofractionated dose regimen. We report results of a prospective Phase II clinical trial of stereotactic body radiotherapy (SBRT) for localized prostate cancer. Methods and Materials: Forty-one low-risk prostate cancer patients with 6 months' minimum follow-up received 36.25 Gy in five fractions of 7.25 Gy with image-guided SBRT alone using the CyberKnife. The early (<3 months) and late (>6 months) urinary and rectal toxicities were assessed using validated quality of life questionnaires (International Prostate Symptom Score, Expanded Prostate Cancer Index Composite) and the Radiation Therapy Oncology Group (RTOG) toxicity criteria. Patterns of prostate-specific antigen (PSA) response are analyzed. Results: The median follow-up was 33 months. There were no RTOG Grade 4 acute or late rectal/urinary complications. There were 2 patients with RTOG Grade 3 late urinary toxicity and none with RTOG Grade 3 rectal complications. A reduced rate of severe rectal toxicities was observed with every-other-day vs. 5 consecutive days treatment regimen (0% vs. 38%, p = 0.0035). A benign PSA bounce (median, 0.4 ng/mL) was observed in 12 patients (29%) occurring at 18 months (median) after treatment. At last follow-up, no patient has had a PSA failure regardless of biochemical failure definition. Of 32 patients with 12 months minimum follow-up, 25 patients (78%) achieved a PSA nadir {<=}0.4 ng/mL. A PSA decline to progressively lower nadirs up to 3 years after treatment was observed. Conclusions: The early and late toxicity profile and PSA response for prostate SBRT are highly encouraging. Continued accrual and follow-up will be necessary to confirm durable biochemical control rates and low toxicity profiles.

  11. Results of patient specific quality assurance for patients undergoing stereotactic ablative radiotherapy for lung lesions.

    PubMed

    Hardcastle, Nicholas; Clements, Natalie; Chesson, Brent; Aarons, Yolanda; Cramb, Jim; Siva, Shankar; Wanigaratne, Derrick M; Ball, David; Kron, Tomas

    2014-03-01

    Hypofractionated image guided radiotherapy of extracranial targets has become increasingly popular as a treatment modality for inoperable patients with one or more small lesions, often referred to as stereotactic ablative body radiotherapy (SABR). This report details the results of the physical quality assurance (QA) program used for the first 33 lung cancer SABR radiotherapy 3D conformal treatment plans in our centre. SABR involves one or few fractions of high radiation dose delivered in many small fields or arcs with tight margins to mobile targets often delivered through heterogeneous media with non-coplanar beams. We have conducted patient-specific QA similar to the more common intensity modulated radiotherapy QA with particular reference to motion management. Individual patient QA was performed in a Perspex phantom using point dose verification with an ionisation chamber and radiochromic film for verification of the dose distribution both with static and moving detectors to verify motion management strategies. While individual beams could vary by up to 7%, the total dose in the target was found to be within ±2% of the prescribed dose for all 33 plans. Film measurements showed qualitative and quantitative agreement between planned and measured isodose line shapes and dimensions. The QA process highlighted the need to account for couch transmission and demonstrated that the ITV construction was appropriate for the treatment technique used. QA is essential for complex radiotherapy deliveries such as SABR. We found individual patient QA helpful in setting up the technique and understanding potential weaknesses in SABR workflow, thus providing confidence in SABR delivery.

  12. Stereotactic localization and removal of a bullet in the third ventricle causing obstructive hydrocephalus after a cerebral gunshot wound: case report.

    PubMed

    Linskey, M E; Kondziolka, D; Marion, D W

    1994-06-01

    A bullet, lodged in the pineal-posterior region of the third ventricle and causing obstructive hydrocephalus, was removed without damage to critical adjacent vascular structures using stereotactic localization followed by laser-guided stereotactic craniotomy. Stereotactic techniques provided precise target localization and allowed dissection to be restricted to the previously injured missile track, thus avoiding any additional morbidity from the surgical procedure.

  13. Dosimetric Impact of the Interplay Effect During Stereotactic Lung Radiation Therapy Delivery Using Flattening Filter-Free Beams and Volumetric Modulated Arc Therapy

    SciTech Connect

    Ong, Chin Loon; Dahele, Max; Slotman, Ben J.; Verbakel, Wilko F.A.R.

    2013-07-15

    Purpose: We investigated the dosimetric impact of the interplay effect during RapidArc stereotactic body radiation therapy for lung tumors using flattening filter-free (FFF) beams with different dose rates. Methods and Materials: Seven tumors with motion ≤20 mm, treated with 10-MV FFF RapidArc, were analyzed. A programmable phantom with sinusoidal longitudinal motion (30-mm diameter “tumor” insert; period = 5 s; individualized amplitude from planning 4-dimensional computed tomography) was used for dynamic dose measurements. Measurements were made with GafChromic EBT III films. Plans delivered the prescribed dose to 95% of the planning target volume, created by a 5-mm expansion of the internal target volume. They comprised 2 arcs and maximum dose rates of 400 and 2400 MU/min. For 2400 MU/min plans, measurements were repeated at 3 different initial breathing phases to model interplay over 2 to 3 fractions. For 3 cases, 2 extra plans were created using 1 full rotational arc (with contralateral lung avoidance sector) and 1 partial arc of 224° to 244°. Dynamic and convolved static measurements were compared by use of gamma analysis of 3% dose difference and 1 mm distance-to-agreement. Results: For 2-arc 2400 MU/min plans, maximum dose deviation of 9.4% was found in a single arc; 7.4% for 2 arcs (single fraction) and <5% and 3% when measurements made at 2 and 3 different initial breathing phases were combined, simulating 2 or 3 fractions. For all 7 cases, >99% of the area within the region of interest passed the gamma criteria when all 3 measurements with different initial phases were combined. Single-fraction single-arc plans showed higher dose deviations, which diminished when dose distributions were summed over 2 fractions. All 400 MU/min plans showed good agreement in a single fraction measurement. Conclusion: Under phantom conditions, single-arc and single-fraction 2400 MU/min FFF RapidArc lung stereotactic body radiation therapy is susceptible to interplay

  14. A writing device improves writing in primary writing tremor.

    PubMed

    Espay, A J; Hung, S W; Sanger, T D; Moro, E; Fox, S H; Lang, A E

    2005-05-10

    Primary writing tremor (PWT) is task-specific and interferes with handwriting. Several reports have shown a beneficial response of this disorder to stereotactic functional neurosurgery. Significant improvement with a writing device was demonstrated with blind rating of handwriting and spiral drawing samples collected before and during its use in nine patients with PWT, suggesting that this therapeutic modality should be tried before considering chronic pharmacotherapy or functional neurosurgery.

  15. Improved survival with stereotactic ablative radiotherapy (SABR) over lobectomy for early stage non-small cell lung cancer (NSCLC): addressing the fallout of disruptive randomized data

    PubMed Central

    Kavanagh, Brian D.; Karam, Sana D.

    2015-01-01

    The gold-standard therapy for early stage non-small cell lung cancer (esNSCLC) has historically been lobectomy with mediastinal lymph node dissection. However, up to one-third of patients with esNSCLC are considered medically-inoperable due to factors such as advanced age and comorbid illnesses. The past decade has witnessed a dramatic increase in the use of high-dose conformal radiotherapy delivered over 1-5 fractions, synonymously termed stereotactic ablative radiotherapy (SABR) or stereotactic body radiation therapy (SBRT). High rates of tumor control and favorable toxicity profiles have led to the adoption of SABR as the treatment of choice for medically-inoperable patients. Limited but growing data exist using SABR for medically-operable patients who are also candidates for lobectomy. A recent pooled analysis of two multicenter prospective randomized trials, the STARS (NCT00840749) and ROSEL (NCT00687986) protocols, published by Chang and colleagues (PMID 25981812) reported improved overall survival (OS) and reduced toxicity with SABR over lobectomy for medically-operable patients with esNSCLC. In this article we review the outcomes of this analysis in the context of existing radiotherapy and surgical data for NSCLC. Further, we discuss the potential causes and implications of these provocative results, including the shifting balance between oncologic control and treatment-related mortality in comparisons of SABR and surgical resection, termed the Head Start Effect. PMID:26244136

  16. Integral dose and radiation-induced secondary malignancies: comparison between stereotactic body radiation therapy and three-dimensional conformal radiotherapy.

    PubMed

    D'Arienzo, Marco; Masciullo, Stefano G; de Sanctis, Vitaliana; Osti, Mattia F; Chiacchiararelli, Laura; Enrici, Riccardo M

    2012-11-19

    The aim of the present paper is to compare the integral dose received by non-tumor tissue (NTID) in stereotactic body radiation therapy (SBRT) with modified LINAC with that received by three-dimensional conformal radiotherapy (3D-CRT), estimating possible correlations between NTID and radiation-induced secondary malignancy risk. Eight patients with intrathoracic lesions were treated with SBRT, 23 Gy × 1 fraction. All patients were then replanned for 3D-CRT, maintaining the same target coverage and applying a dose scheme of 2 Gy × 32 fractions. The dose equivalence between the different treatment modalities was achieved assuming α/β = 10 Gy for tumor tissue and imposing the same biological effective dose (BED) on the target (BED = 76 Gy(10)). Total NTIDs for both techniques was calculated considering α/β = 3 Gy for healthy tissue. Excess absolute cancer risk (EAR) was calculated for various organs using a mechanistic model that includes fractionation effects. A paired two-tailed Student t-test was performed to determine statistically significant differences between the data (p ≤ 0.05). Our study indicates that despite the fact that for all patients integral dose is higher for SBRT treatments than 3D-CRT (p = 0.002), secondary cancer risk associated to SBRT patients is significantly smaller than that calculated for 3D-CRT (p = 0.001). This suggests that integral dose is not a good estimator for quantifying cancer induction. Indeed, for the model and parameters used, hypofractionated radiotherapy has the potential for secondary cancer reduction. The development of reliable secondary cancer risk models seems to be a key issue in fractionated radiotherapy. Further assessments of integral doses received with 3D-CRT and other special techniques are also strongly encouraged.

  17. The Technique, Resources and Costs of Stereotactic Body Radiotherapy of Prostate Cancer: A Comparison of Dose Regimens and Delivery Systems.

    PubMed

    Sharieff, Waseem; Greenspoon, Jeffrey N; Dayes, Ian; Chow, Tom; Wright, James; Lukka, Himu

    2016-02-01

    Robotic system has been used for stereotactic body radiotherapy (SBRT) of prostate cancer. Arc-based and fixed-gantry systems are used for hypofractionated regimens (10-20 fractions) and the standard regimen (39 fractions); they may also be used to deliver SBRT. Studies are currently underway to compare efficacy and safety of these systems and regimens. Thus, we describe the technique and required resources for the provision of robotic SBRT in relation to the standard regimen and other systems to guide investment decisions. Using administrative data of resource volumes and unit prices, we computed the cost per patient, cost per cure and cost per quality adjusted life year (QALY) of four regimens (5, 12, 20 and 39 fractions) and three delivery systems (robotic, arc-based and fixed-gantry) from a payer's perspective. We performed sensitivity analyses to examine the effects of daily hours of operation and in-room treatment delivery times on cost per patient. In addition, we estimated the budget impact when a robotic system is preferred over an arc-based or fixed-gantry system. Costs of SBRT were $6333/patient (robotic), $4368/patient (arc-based) and $4443/patient (fixed-gantry). When daily hours of operation were varied, the cost of robotic SBRT varied from $9324/patient (2 hours daily) to $5250/patient (10 hours daily). This was comparable to the costs of 39 fraction standard regimen which were $5935/patient (arc-based) and $7992/ patient (fixed-gantry). In settings of moderate to high patient volume, robotic SBRT is cost effective compared to the standard regimen. If SBRT can be delivered with equivalent efficacy and safety, the arc-based system would be the most cost effective system.

  18. Comparison of Effects Between Central and Peripheral Stage I Lung Cancer Using Image-Guided Stereotactic Body Radiotherapy via Helical Tomotherapy.

    PubMed

    He, Jian; Huang, Yan; Shi, Shiming; Hu, Yong; Zeng, Zhaochong

    2015-12-01

    Lung cancer is a common malignant tumor with high morbidity and mortality. Here we compared the effects and outcome between central and peripheral stage I lung cancer using image-guided stereotactic body radiotherapy. From June 2011 to July 2013, a total of 33 patients with stage I lung cancer were enrolled. A total of 50 Gy in 10 fractions or 60 Gy in 10 fractions was delivered in the central arm (n = 18), while 50 Gy in 5 fractions in the peripheral arm (n = 15). Statistical analyses were performed using logistic regression analysis and Kaplan-Meier method. The mean follow-up time was 38.1 months. Three-month, 1-, 2-, and 3-year overall response rates were 66.7%, 83.3%, 61.1%, and 72.2% and 66.7%, 80%, 80%, and 80% in the central and peripheral arms, respectively. Three-year local control rates (94.4% vs 93.3%, P = .854), regional control rates (94.4% vs 86.7%, P = .412), and distant control rates (64.2% vs 61.7%, P = .509) had no differences between the central and the peripheral arms. Grade 2 radiation pneumonitis was observed in 6 of 18 patients in the central arm and in 1 of 15 patients in the peripheral arm (P = .92). Grade 2 radiation esophagitis was 5.7% in the central arm, while none occurred in the peripheral arm (P = .008). Five (15.1%) of all patients felt slight fatigue during radiotherapy. Other major complications were not observed. In conclusion, helical image-guided stereotactic body radiotherapy for central stage I lung cancer is safe and effective compared to peripheral stage I lung cancer.

  19. Radiosurgery for Brain Metastases From Unknown Primary Cancers

    SciTech Connect

    Niranjan, Ajay; Kano, Hideyuki; Khan, Aftab; Kim, In-Young; Kondziolka, Douglas; Flickinger, John C.; Lunsford, L. Dade

    2010-08-01

    Purpose: We evaluated the role of Gamma Knife stereotactic radiosurgery in the multidisciplinary management of brain metastases from an undiagnosed primary cancer. Methods and Materials: Twenty-nine patients who had solitary or multiple brain metastases without a detectable primary site underwent stereotactic radiosurgery between January 1990 and March 2007 at the University of Pittsburgh. The median patient age was 61.7 years (range, 37.9-78.7 years). The median target volume was 1.0 cc (range, 0.02-23.6 cc), and the median margin radiosurgical dose was 16 Gy (range, 20-70 Gy). Results: After radiosurgery, the local tumor control rate was 88.5%. Twenty four patients died and 5 patients were living at the time of this analysis. The overall median survival was 12 months. Actuarial survival rates from stereotactic radiosurgery at 1 and 2 years were 57.2% and 36.8%, respectively. Factors associated with poor progression-free survival included large tumor volume (3 cc or more) and brainstem tumor location. Conclusions: Radiosurgery is an effective and safe minimally invasive option for patients with brain metastases from an unknown primary site.

  20. Modification of the Gouda frame to allow stereotactic biopsy of the brain using the GE 8800 computed tomographic scanner.

    PubMed

    Gouda, K I; Freidberg, S R; Larsen, C R; Baker, R A; Silverman, M L

    1983-08-01

    The Gouda stereotactic frame has been modified to interface with the GE 8800 scanner. The patient, attached to the frame, is scanned and then moved to the operating room for a stereotactic biopsy. This is a safe, accurate method of obtaining biopsy specimens of otherwise inaccessible tumors of the brain.

  1. Greatly improved neuroprotective efficiency of citicoline by stereotactic delivery in treatment of ischemic injury.

    PubMed

    Xu, Fangjingwei; Hongbin Han; Yan, Junhao; Chen, He; He, Qingyuan; Xu, Weiguo; Zhu, Ning; Zhang, Hong; Zhou, Fugen; Lee, Kejia

    2011-01-01

    Limited penetration of neuroprotective drug citicoline into the central nervous system (CNS) by systemic administration led to poor efficiency. A novel method of stereotactic drug delivery was explored to make citicoline bypass the blood brain barrier (BBB) and take effect by direct contact with ischemic neurons. A permanent middle cerebral artery occlusion (pMCAO) model of rats was prepared. To get the optimal conditions for citicoline administration by the novel stereotactic delivery pathway, magnetic resonance imaging (MRI) tracer method was used, and a dose-dependent effect was given. Examinations of MRI, behavior evaluation, infarct volume assessment and histological staining were performed to evaluate the outcome. This MRI-guided stereotactic delivery of citicoline resulted in a notable reduction (>80%) in infarct size and a delayed ischemic injury in cortex 12 hours after onset of acute ischemia when compared with the systematic delivery. The improved neuroprotective efficiency was realized by a full distribution of citicoline in most of middle cerebral artery (MCA) territory and an adequate drug reaction in the involved areas of the brain. Brain lesions of treated rats by stereotactic delivery of citicoline were well predicted in the lateral ventricle and thalamus due to a limited drug deposition by MRI tracer method. Our study realized an improved neuroprotective efficiency of citicoline by stereotactic delivery, and an optimal therapeutic effect of this administration pathway can be achieved under MRI guidance.

  2. Stereotactic Body Radiotherapy for Inoperable Liver Tumors: Results of a Single Institutional Experience

    PubMed Central

    Hijazi, Hussam; Campeau, Marie-Pierre; Roberge, David; Donath, David; Lapointe, Real; Vandenbroucke-Menu, Franck; Taussky, Daniel; Boudam, Karim; Chan, Gabriel; Bujold, Alexis

    2016-01-01

    Objectives Stereotactic body radiation therapy (SBRT) is an emerging treatment option for liver tumors unsuitable for ablation or surgery. We report our experience with SBRT in the treatment of liver tumors. Materials and methods Patients with primary or secondary liver cancer were identified in our local SBRT database. Patients were included irrespective of prior liver-directed therapies. The primary endpoint of our review was in-field local control (LC). Secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity. Results From 2009 to 2015, a total of 71 liver lesions in 68 patients were treated with SBRT (three patients had two liver lesions treated). The median age was 71 years (27–89 years). Hepatocellular carcinoma (HCC) was the diagnosis in 23 patients (34%), with the grade of Child–Pugh A (52%), B (39%), or C (nine percent) cirrhosis. Six patients (nine percent) had intrahepatic cholangiocarcinoma (IHC). The remaining 39 patients (57%) had metastatic liver lesions. Colorectal adenocarcinoma was the most common primary tumor type (81%). The median size for HCC, IHC, and metastatic lesions was 5 cm (2–9 cm), 3.6 cm (2–4.9 cm), and 4 cm (1–8 cm), respectively. The median prescribed dose was 45 Gy (16–50 Gy). Median follow-up was 11.5 months (1–45 months). Actuarial one-year in-field LC for HCC and metastatic lesions was 85% and 64% respectively (p= 0.66). At one year, the actuarial rate of new liver lesions was 40% and 26%, respectively, (p=0.58) for HCC and metastases. Only six patients with IHC were treated with SBRT in this study – in these patients, one-year LC was 78% with new liver lesions in 53%. The SBRT treatments were well tolerated. The side effects included common criteria for adverse events (CTCAE) v4 grade 1 acute gastrointestinal toxicity in three patients, grade 3 nausea in one patient, and grade 3 acute dermatitis in another patient. Two patients had grade 5 toxicity. Radiation pneumonitis was

  3. Dosimetric effects of positioning shifts using 6D-frameless stereotactic Brainlab system in hypofractionated intracranial radiotherapy.

    PubMed

    Jin, Hosang; Keeling, Vance P; Ali, Imad; Ahmad, Salahuddin

    2016-01-01

    Dosimetric consequences of positional shifts were studied using frameless Brainlab ExacTrac X-ray system for hypofractionated (3 or 5 fractions) intracranial stereotactic radiotherapy (SRT). SRT treatments of 17 patients with metastatic intracranial tumors using the stereotactic system were retrospectively investigated. The treatments were simulated in a treatment planning system by modifying planning parameters with a matrix conversion technique based on positional shifts for initial infrared (IR)-based setup (XC: X-ray correction) and post-correction (XV: X-ray verification). The simulation was implemented with (a) 3D translational shifts only and (b) 6D translational and rotational shifts for dosimetric effects of angular correction. Mean translations and rotations (± 1 SD) of 77 fractions based on the initial IR setup (XC) were 0.51±0.86 mm (lateral), 0.30±1.55 mm (longitudinal), and -1.63±1.00 mm (vertical); 0.53±0.56 mm (pitch), 0.42±0.60 mm (roll), and 0.44±0.90 mm (yaw), respectively. These were -0.07±0.24 mm, -0.07±0.25 mm, 0.06±0.21 mm, 0.04±0.23 mm, 0.00±0.30 mm, and 0.02±0.22 mm, respectively, for the postcorrection (XV). Substantial degradation of the treatment plans was observed in D95 of PTV (2.6%±3.3%; simulated treatment versus treatment planning), Dmin of PTV (13.4%±11.6%), and Dmin of CTV (2.8%±3.8%, with the maximum error of 10.0%) from XC, while dosimetrically negligible changes (< 0.1%) were detected for both CTV and PTV from XV simulation. 3D angular correction significantly improved CTV dose coverage when the total angular shifts (|pitch|+|roll|+|yaw|) were greater than 2°. With the 6D stereoscopic X-ray verification imaging and frameless immobilization, submillimeter and subdegree accuracy is achieved with negligible dosimetric deviations. 3D angular correction is required when the angular deviation is substantial. A CTV-to-PTV safety margin of 2 mm is large enough to prevent deterioration of CTV

  4. Dosimetric effects of positioning shifts using 6D-frameless stereotactic Brainlab system in hypofractionated intracranial radiotherapy.

    PubMed

    Jin, Hosang; Keeling, Vance P; Ali, Imad; Ahmad, Salahuddin

    2016-01-08

    Dosimetric consequences of positional shifts were studied using frameless Brainlab ExacTrac X-ray system for hypofractionated (3 or 5 fractions) intracranial stereo-tactic radiotherapy (SRT). SRT treatments of 17 patients with metastatic intracranial tumors using the stereotactic system were retrospectively investigated. The treatments were simulated in a treatment planning system by modifying planning parameters with a matrix conversion technique based on positional shifts for initial infrared (IR)-based setup (XC: X-ray correction) and post-correction (XV: X-ray verification). The simulation was implemented with (a) 3D translational shifts only and (b) 6D translational and rotational shifts for dosimetric effects of angular correction. Mean translations and rotations (± 1 SD) of 77 fractions based on the initial IR setup (XC) were 0.51 ± 0.86 mm (lateral), 0.30 ± 1.55 mm (longitudinal), and -1.63 ± 1.00 mm (vertical); -0.53° ± 0.56° (pitch), 0.42° ± 0.60° (roll), and 0.44°± 0.90° (yaw), respectively. These were -0.07 ± 0.24 mm, -0.07 ± 0.25 mm, 0.06± 0.21 mm, 0.04° ± 0.23°, 0.00° ± 0.30°, and -0.02° ± 0.22°, respectively, for the postcorrection (XV). Substantial degradation of the treatment plans was observed in D95 of PTV (2.6% ± 3.3%; simulated treatment versus treatment planning), Dmin of PTV (13.4% ± 11.6%), and Dmin of CTV (2.8% ± 3.8%, with the maximum error of 10.0%) from XC, while dosimetrically negligible changes (< 0.1%) were detected for both CTV and PTV from XV simulation. 3D angular correction significantly improved CTV dose coverage when the total angular shifts (|pitch| + |roll| + |yaw|) were greater than 2°. With the 6D stereoscopic X-ray verification imaging and frameless immobilization, submillimeter and subdegree accuracy is achieved with negligible dosimetric deviations. 3D angular correction is required when the angular deviation is substantial. A CTV-to-PTV safety margin of 2 mm is large enough to prevent

  5. A Rabbit Irradiation Platform for Outcome Assessment of Lung Stereotactic Radiosurgery

    SciTech Connect

    Cai Jing; Mata, Jaime F.; Orton, Matthew D.; Hagspiel, Klaus D.; Mugler, John P.; Larner, James M.; Sheng Ke; Read, Paul W.

    2009-04-01

    Purpose: To evaluate a helical tomotherapy-based rodent radiosurgery platform that reproduces human image-guided radiosurgery treatment to study radiobiologic effects of stereotactic radiosurgery on lung tissues using functional magnetic resonance imaging (MRI). Methods and Materials: Hypofractionated radisourgery (20 Gy x 3) was delivered to the right lung of three New Zealand rabbits using Helical TomoTherapy with MVCT image guidance. Contrast-enhanced MR perfusion, hyperpolarized heliu