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Sample records for cyberknife radiotherapie robotisee

  1. 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

  2. Stereotactic body radiotherapy in prostate cancer: is rapidarc a better solution than cyberknife?

    PubMed

    Macdougall, N D; Dean, C; Muirhead, R

    2014-01-01

    There is increasing interest in stereotactic body radiotherapy (SBRT) for the management of prostate adenocarcinoma, with encouraging initial biological progression-free survival results. However, the limited literature is dominated by the use of the Cyberknife platform. This led to an international phase III study comparing outcomes for Cyberknife SBRT with both surgery and conventionally fractionated intensity-modulated radiotherapy (the PACE study). We aim to compare Cyberknife delivery with Rapidarc, a more widely available treatment platform. The scans of six previous prostate radiotherapy patients with a range of prostate sizes were chosen. The clinical target volume was defined as the prostate gland, with 3 mm added for the Cyberknife planning target volume (PTV) and 5 mm for the Rapidarc PTV. Accuray multiplan v. 4.5 was used for planning with delivery on a Cyberknife VSI system v9.5; Varian Eclipse v10 was used for Rapidarc planning with delivery using a Varian 21EX linear accelerator. Both systems attempted to deliver at least 35 Gy to the PTV in five fractions with PTV heterogeneity <12%. All organ at risk (OAR) constraints were achieved by both platforms, whereas the Cyberknife failed to achieve the desired PTV homogeneity constraint in two cases. In other OARs without constraints, Cyberknife delivered higher doses. The volume of the 35 Gy isodose was slightly larger with Rapidarc, but conversely at doses <35 Gy normal tissues received higher doses with Cyberknife. The mean planning and delivery time was in favour of Rapidarc. We have shown that there is no discernible dosimetric advantage to choosing Cyberknife over Rapidarc for SBRT delivery in prostate cancer. Given the significant benefits of Rapidarc in terms of availability, planning and delivery time, the authors suggest that phase III trials of SBRT should include Rapidarc or equivalent rotational delivery platforms. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd

  3. A noninvasive eye fixation monitoring system for CyberKnife radiotherapy of choroidal and orbital tumors

    SciTech Connect

    Daftari, I. K.; Petti, P. L.; Larson, D. A.; O'Brien, J. M.; Phillips, T. L.

    2009-03-15

    A new noninvasive monitoring system for fixing the eye has been developed to treat orbital and choroidal tumors with CyberKnife-based radiotherapy. This device monitors the eye during CT/MRI scanning and during treatment. The results of this study demonstrate the feasibility of the fixation light system for CyberKnife-based treatments of orbital and choroidal tumors and supports the idea that larger choroidal melanomas and choroidal metastases could be treated with CyberKnife without implanting fiducial markers.

  4. 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.

  5. [Cyberknife robotic stereotactic radiotherapy: technical aspects and recent developments].

    PubMed

    Thariat, J; Marcié, S; Marcy, P-Y; Trimaud, R; Angellier, G; Mammar, H; Bondiau, P-Y; Gerard, J-P

    2010-07-01

    Cyberknife (Accuray Inc. Sunnyvale, USA) stereotactic body radiation therapy (SBRT) involves the delivery of a small number of large doses of radiation to a target volume using continuously evolving advanced technology. It has emerged as a novel treatment modality for cancer and modified some concepts of cancer treatment. It is indicated in early-stage primary cancer, sometimes as an alternative to surgery. It is also indicated for patients with oligometastatic disease who have relatively long survival with the aim to optimize disease control with a good quality of life. Although there remain some uncertainties regarding the radiobiology of hypofractionation, local control and tolerance have been promising. Indications are increasing under strict quality assurance programs worldwide and prospective clinical evaluation.

  6. [Emergency oncology cases for whom stereotactic radiotherapy by cyberknife proved effective for cerebellar metastasis of lung cancer].

    PubMed

    Miyamoto, Shingo; Ikushima, Soichiro; Inomata, Minoru; Nomura, Ryutaro; Suzuki, Ichiro

    2013-08-01

    Cerebellar metastasis sometimes causes symptoms such as ataxia and dizziness, or hydrocephalus by compression of the fourth ventricle, making emergency treatment necessary. We report two cases for whom we performed emergency stereotactic radiotherapy, and whose tumors decreased and symptoms improved. Case 1: A 58-year-old male was diagnosed with small cell lung cancer in December 2008, and received chemotherapy and conventional radiotherapy at another hospital. He developed difficulty in walking and experienced nausea from March 2010 on. Because neoplastic lesions had been found in the cerebellar vermis on computed tomography(CT)scan, he was referred to our hospital. We urgently performed stereotactic radiotherapy by CyberKnife, and his symptoms then improved. As a chest CT scan revealed a mass lesion in his right upper lobe, the diagnosis of recurrent small cell lung cancer was made, and we performed chemotherapy sequentially. Case 2: A 73-year-old female experienced severe headache and dizziness and noticed difficulty in walking in July 2010. Because neoplastic lesions had been found in the left cerebellar hemisphere on CT scan at another hospital, she was referred to our hospital. Chest X-ray films showed a mass lesion in the left middle lung field and cytologic examination of sputum showed squamous cell carcinoma. We urgently performed stereotactic radiotherapy by CyberKnife, and her symptoms then improved. Therefore, we performed chemotherapy sequentially. Stereotactic radiotherapy by CyberKnife is less invasive, and is one good treatment option in the event of an emergency.

  7. Equivalent normalized total dose estimates in cyberknife radiotherapy dose delivery in prostate cancer hypofractionation regimens.

    PubMed

    Sudahar, H; Kurup, P G G; Murali, V; Mahadev, P; Velmurugan, J

    2012-04-01

    As the α/β value of prostate is very small and lower than the surrounding critical organs, hypofractionated radiotherapy became a vital mode of treatment of prostate cancer. Cyberknife (Accuray Inc., Sunnyvale, CA, USA) treatment for localized prostate cancer is performed in hypofractionated dose regimen alone. Effective dose escalation in the hypofractionated regimen can be estimated if the corresponding conventional 2 Gy per fraction equivalent normalized total dose (NTD) distribution is known. The present study aims to analyze the hypofractionated dose distribution of localized prostate cancer in terms of equivalent NTD. Randomly selected 12 localized prostate cases treated in cyberknife with a dose regimen of 36.25 Gy in 5 fractions were considered. The 2 Gy per fraction equivalent NTDs were calculated using the formula derived from the linear quadratic (LQ) model. Dose distributions were analyzed with the corresponding NTDs. The conformity index for the prescribed target dose of 36.25 Gy equivalent to the NTD dose of 90.63 Gy (α/β = 1.5) or 74.31 Gy (α/β = 3) was ranging between 1.15 and 1.73 with a mean value of 1.32 ± 0.15. The D5% of the target was 111.41 ± 8.66 Gy for α/β = 1.5 and 90.15 ± 6.57 Gy for α/β = 3. Similarly, the D95% was 91.98 ± 3.77 Gy for α/β = 1.5 and 75.35 ± 2.88 Gy for α/β = 3. The mean values of bladder and rectal volume receiving the prescribed dose of 36.25 Gy were 0.83 cm3 and 0.086 cm3, respectively. NTD dose analysis shows an escalated dose distribution within the target for low α/β (1.5 Gy) with reasonable sparing of organs at risk. However, the higher α/β of prostate (3 Gy) is not encouraging the fact of dose escalation in cyberknife hypofractionated dose regimen of localized prostate cancer.

  8. Peripheral dose in ocular treatments with CyberKnife and Gamma Knife radiosurgery compared to proton radiotherapy

    NASA Astrophysics Data System (ADS)

    Zytkovicz, A.; Daftari, I.; Phillips, T. L.; Chuang, C. F.; Verhey, L.; Petti, P. L.

    2007-09-01

    Peripheral radiation can have deleterious effects on normal tissues throughout the body, including secondary cancer induction and cataractogenesis. The aim of this study is to evaluate the peripheral dose received by various regions of the body after ocular treatment delivered with the Model C Gamma Knife, proton radiotherapy with a dedicated ocular beam employing no passive-scattering system, or a CyberKnife unit before and after supplemental shielding was introduced. TLDs were used for stray gamma and x-ray dosimetry, whereas CR-39 dosimeters were used to measure neutron contamination in the proton experiments. Doses to the contralateral eye, neck, thorax and abdomen were measured on our anthropomorphic phantom for a 56 Gy treatment to a 588 mm3 posterior ocular lesion. Gamma Knife (without collimator blocking) delivered the highest dose in the contralateral eye, with 402-2380 mSv, as compared with 118-234 mSv for CyberKnife pre-shielding, 46-255 mSv for CyberKnife post-shielding and 9-12 mSv for proton radiotherapy. Gamma Knife and post-shielding CyberKnife delivered comparable doses proximal to the treatment site, with 190 versus 196 mSv at the thyroid, whereas protons doses at these locations were less than 10 mSv. Gamma Knife doses decreased dramatically with distance from the treatment site, delivering only 13 mSv at the lower pelvis, comparable to the proton result of 4 to 7 mSv in this region. In contrast, CyberKnife delivered between 117 and 132 mSv to the lower pelvis. In conclusion, for ocular melanoma treatments, a proton beam employing no double scattering system delivers the lowest peripheral doses proximally to the contralateral eye and thyroid when compared to radiosurgery with the Model C Gamma Knife or CyberKnife. At distal locations in the pelvis, peripheral doses delivered with proton and Gamma Knife are of an order of magnitude smaller than those delivered with CyberKnife.

  9. Dosimetric evaluation of four-dimensional dose distributions of CyberKnife and volumetric-modulated arc radiotherapy in stereotactic body lung radiotherapy.

    PubMed

    Chan, Mark K H; Kwong, Dora L W; Law, Gilbert M L; Tam, Eric; Tong, Anthony; Lee, Venus; Ng, Sherry C Y

    2013-07-08

    Advanced image-guided stereotatic body lung radiotherapy techniques using volumetric-modulated arc radiotherapy (VMAT) with four-dimensional cone-beam computed tomography (4D CBCT) and CyberKnife with real-time target tracking have been clinically implemented by different authors. However, dosimetric comparisons between these techniques are lacking. In this study, 4D CT scans of 14 patients were used to create VMAT and CyberKnife treatment plans using 4D dose calculations. The GTV and the organs at risk (OARs) were defined on the end-exhale images for CyberKnife planning and were then deformed to the midventilation images (MidV) for VMAT optimization. Direct 4D Monte Carlo dose optimizations were performed for CyberKnife (4D(CK)). Four-dimensional dose calculations were also applied to VMAT plans to generate the 4D dose distributions (4D(VMAT)) on the exhale images for direct comparisons with the 4D(CK) plans. 4D(CK) and 4D(VMAT) showed comparable target conformity (1.31 ± 0.13 vs. 1.39 ± 0.24, p = 0.05). GTV mean doses were significantly higher with 4D(CK). Statistical differences of dose volume metrics were not observed in the majority of OARs studied, except for esophagus, with 4D(VMAT) yielding marginally higher D1% than 4D(CK). The normal tissue volumes receiving 80%, 50%, and 30% of the prescription dose (V80%, V50%, and V30%) were higher with 4D(VMAT), whereas 4D(CK) yielded slightly higher V10% in posterior lesions than 4D(VMAT). VMAT resulted in much less monitor units and therefore greater delivery efficiency than CyberKnife. In general, it was possible to produce dosimetrically acceptable plans with both techniques. The selection of treatment modality should consider the dosimetric results as well as the patient's tolerance of the treatment process specific to the SBRT technique.

  10. 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.

  11. 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.

  12. Usefulness of Stereotactic Radiotherapy Using CyberKnife for Recurrent Lymph Node Metastasis of Differentiated Thyroid Cancer

    PubMed Central

    Higashiyama, Shigeaki; Sougawa, Mitsuharu; Yoshida, Atsushi; Shiomi, Susumu

    2017-01-01

    A woman in her 60s presented with a recurrent lymph node metastasis from a papillary thyroid carcinoma in the right parapharyngeal space. She had already undergone total thyroidectomy, five resections for cervical lymph node metastases, and right carotid rebuilding. Surgical resection of the current metastasis was impossible. 131I-radioiodine therapy (RIT) with 3.7 GBq 131I was not effective; therefore, stereotactic radiation therapy (SRT) using a CyberKnife radiotherapy system was scheduled. The prescription dose was 21 Gy, and a dose covering 95% of the planning target volume (PTV) in three fractions was administered. The PTV was 4,790 mm3. Follow-up magnetic resonance imaging conducted 3 and 12 months after the SRT demonstrated a remarkable and gradual reduction of the recurrent lymph node metastasis in the right parapharyngeal space and no evidence of recurrence. For multidisciplinary therapy of unresectable and/or RIT unresponsive locoregional lymph node metastases and recurrences of DTC, SRT using the CyberKnife system should be considered.

  13. 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.

  14. 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.

  15. Direct tumor in vivo dosimetry in highly-conformal radiotherapy: A feasibility study of implantable MOSFETs for hypofractionated extracranial treatments using the Cyberknife system

    SciTech Connect

    Scalchi, Paolo; Righetto, Roberto; Cavedon, Carlo; Francescon, Paolo; Colombo, Federico

    2010-04-15

    Purpose: In highly-conformal radiotherapy, due to the complexity of both beam configurations and dose distributions, traditional in vivo dosimetry is unpractical or even impossible. The ideal dosimeter would be implanted inside the planning treatment volume so that it can directly measure the total delivered dose during each fraction with no additional uncertainty due to calculation models. The aim of this work is to verify if implantable metal oxide semiconductors field effect transistors (MOSFETs) can achieve a sufficient degree of dosimetric accuracy when used inside extracranial targets undergoing radiotherapy treatments using the Cyberknife system. Methods: Based on the preliminary findings of this study, new prototypes for high dose fractionations were developed to reduce the time dependence for long treatment delivery times. These dosimeters were recently cleared and are marketed as DVS-HFT. Multiple measurements were performed using both Virtual Water and water phantoms to characterize implantable MOSFETs under the Cyberknife beams, and included the reference-dosimetry consistency, the dependence of the response on the collimator size, on the daily delivered dose, and the time irradiation modality. Finally a Cyberknife prostate treatment simulation using a body phantom was conducted, and both MOSFET and ionization readings were compared to Monte Carlo calculations. The feasibility analysis was conducted based on the ratios of the absorbed dose divided by the dose reading, named as ''further calibration factor'' (FCF). Results: The average FCFs resulted to be 0.98 for the collimator dependence test, and about 1.00 for the reference-dosimetry test, the dose-dependence test, and the time-dependence test. The average FCF of the prostate treatment simulation test was 0.99. Conclusions: The obtained results are well within DVS specifications, that is, the factory calibration is still valid for such kind of treatments using the Cyberknife system, with no need of

  16. 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.

  17. Long-term results of hypofractionated stereotactic radiotherapy with CyberKnife for growth hormone-secreting pituitary adenoma: evaluation by the Cortina consensus.

    PubMed

    Iwata, Hiromitsu; Sato, Kengo; Nomura, Ryutaro; Tabei, Yusuke; Suzuki, Ichiro; Yokota, Naoki; Inoue, Mitsuhiro; Ohta, Seiji; Yamada, Shozo; Shibamoto, Yuta

    2016-06-01

    The aim of the present study was to evaluate the safety and feasibility of hypofractionated stereotactic radiotherapy (SRT) with CyberKnife for growth hormone-secreting pituitary adenoma (GH-PA). Fifty-two patients with GH-PA were treated with hypofractionated SRT between September 2001 and October 2012. Eight patients had clinically silent GH-PA and 44 were symptomatic. Only 1 patient was inoperable. The other patients had recurrent or postoperative residual tumors on MRI. All patients had received pharmacotherapy prior to SRT with a somatostatin analog, dopamine agonist, and/or GH receptor antagonist. The marginal doses were 17.4-26.8 Gy for the 3-fraction schedule and 20.0-32.0 Gy for the 5-fraction schedule. Endocrinological remission was assessed by the Cortina consensus criteria 2010 (random GH <1 ng/ml or nadir GH after an oral glucose tolerance test <0.4 ng/ml and normalization of age- and sex-adjusted insulin-like growth factor-1). The median follow-up period was 60 months (range 27-137). The 5-year overall survival, local control, and disease-free survival rates were 100, 100, and 96 %, respectively. Nine patients (5 clinically silent and 4 symptomatic patients) satisfied the Cortina criteria without receiving further pharmacotherapy, whereas the remaining 43 patients did not. No post-SRT grade 2 or higher visual disorder occurred. Symptomatic post-SRT hypopituitarism was observed in 1 patient. CyberKnife hypofractionated SRT is safe and effective when judged by imaging findings for GH-PA. However, it may be difficult to satisfy the Cortina consensus criteria in most symptomatic patients with SRT alone. Further investigations of optimal treatments are warranted.

  18. Poster — Thur Eve — 23: Dose and Position Quality Assurance using the RADPOS System for 4D Radiotherapy with CyberKnife

    SciTech Connect

    Marants, R; Vandervoort, E; Cygler, J E

    2014-08-15

    Introduction: RADPOS 4D dosimetry system consists of a microMOSFET dosimeter combined with an electromagnetic positioning sensor, which allows for performing real-time dose and position measurements simultaneously. In this report the use of RADPOS as an independent quality assurance (QA) tool during CyberKnife 4D radiotherapy treatment is described. In addition to RADPOS, GAFCHROMIC® films were used for simultaneous dose measurement. Methods: RADPOS and films were calibrated in a Solid Water® phantom at 1.5 cm depth, SAD= 80 cm, using 60 mm cone. CT based treatment plan was created for a Solid Water® breast phantom containing metal fiducials and RADPOS probe. Dose calculations were performed using iPlan pencil beam algorithm. Before the treatment delivery, GAFCHROMIC® film was inserted inside the breast phantom, next to the RADPOS probe. Then the phantom was positioned on the chest platform of the QUASAR, to which Synchrony LED optical markers were also attached. Position logging began for RADPOS and the Synchrony tracking system, the QUASAR motion was initiated and the treatment was delivered. Results: RADPOS position measurements very closely matched the LED marker positions recorded by the Synchrony camera tracking system. The RADPOS measured dose was 2.5% higher than the average film measured dose, which is within the experimental uncertainties. Treatment plan calculated dose was 4.1 and 1.6% lower than measured by RADPOS and film, respectively. This is most likely due to the inferior nature of the dose calculation algorithm. Conclusions: Our study demonstrates that RADPOS system is a useful tool for independent QA of CyberKnife treatments.

  19. Dose Gradient Near Target-Normal Structure Interface for Nonisocentric CyberKnife and Isocentric Intensity-Modulated Body Radiotherapy for Prostate Cancer

    SciTech Connect

    Hossain, Sabbir; Xia Ping; Huang, Kim; Descovich, Martina; Chuang, Cynthia; Gottschalk, Alexander R.; Roach, Mack; Ma Lijun

    2010-09-01

    Purpose: The treatment planning quality between nonisocentric CyberKnife (CK) and isocentric intensity modulation treatment was studied for hypofractionated prostate body radiotherapy. In particular, the dose gradient across the target and the critical structures such as the rectum and bladder was characterized. Methods and Materials: In the present study, patients treated with CK underwent repeat planning for nine fixed-field intensity-modulated radiotherapy (IMRT) using identical contour sets and dose-volume constraints. To calculate the dose falloff, the clinical target volume contours were expanded 30 mm anteriorly and posteriorly and 50 mm uniformly in other directions for all patients in the CK and IMRT plans. Results: We found that all the plans satisfied the dose-volume constraints, with the CK plans showing significantly better conformity than the IMRT plans at a relative greater dose inhomogeneity. The rectal and bladder volumes receiving a low dose were also lower for CK than for IMRT. The average conformity index, the ratio of the prescription isodose volume and clinical target volume, was 1.18 {+-} 0.08 for the CK plans vs. 1.44 {+-} 0.11 for the IMRT plans. The average homogeneity index, the ratio of the maximal dose and the prescribed dose to the clinical target volume, was 1.45 {+-} 0.12 for the CK plans vs. 1.28 {+-} 0.06 for the IMRT plans. The average percentage of dose falloff was 2.9% {+-} 0.8%/mm for CK and 3.1% {+-} 1.0%/mm for IMRT in the anterior direction, 3.8% {+-} 1.6%/mm for CK and 3.2% {+-} 1.9%/mm for IMRT in the posterior direction, and 3.6% {+-} 0.4% for CK and 3.6% {+-} 0.4% for IMRT in all directions. Conclusion: Nonisocentric CK was as capable of producing equivalent fast dose falloff as high-number fixed-field IMRT delivery.

  20. SU-E-T-648: Quality Assurance Using the RADPOS System for 4D Radiotherapy with CyberKnife

    SciTech Connect

    Marants, R; Vandervoort, E; Cygler, J E

    2015-06-15

    Purpose: The CyberKnife robotic radiosurgery system uses Synchrony respiratory motion compensation, which requires independent performance verification. In this work, the RADPOS 4D dosimetry system’s motion measurements are compared with internal fiducial position measurements. In addition, RADPOS measurements are compared with Synchrony’s predictive correlation model, which is based on internal fiducial and external LED marker position measurements. Methods: A treatment plan was created for a lung insert containing fiducials, RADPOS detector, and Solid Water tumor phantom. Two Quasar Respiratory Motion Phantoms (Q1 and Q2) and two RADPOS detectors (R1 and R2) were used: Q1 simulated lung motion with a lung insert moving in the superior/inferior direction, while Q2 simulated chest motion with a chest platform moving in the anterior/posterior direction. Before treatment, R1 was secured inside of the tumor phantom within Q1, while LED markers and R2 were positioned on the chest platform of Q2. Two treatment delivery cases were studied: isocentric plan (I) and non-isocentric patient plan (P). Four motion cases were studied: no motion (0), sinusoidal and in-phase (1), sinusoidal and out-of-phase (2), patient waveform and out-of-phase (3). A coordinate alignment algorithm was implemented, allowing RADPOS and model position data to be compared within the fiducial coordinate system. Results: The standard deviation of the differences between RADPOS and fiducial position measurements was below 0.6 mm for all experimental cases. The standard deviation of the differences between RADPOS and model position data was 1.0, 1.5, and 1.6 mm along the primary direction of motion for case I1, I2, and P3, respectively. Conclusion: Our work demonstrates that RADPOS is a useful tool for independent quality assurance of CyberKnife treatment with Synchrony respiratory compensation. RADPOS and fiducial position measurement closely match, and RADPOS confirms the effectiveness of Cyber

  1. Cyberknife Image-Guided Delivery and Quality Assurance

    SciTech Connect

    Dieterich, Sonja; Pawlicki, Todd

    2008-05-01

    The CyberKnife is a complex, emerging technology that is a significant departure from current stereotactic radiosurgery and external beam radiotherapy technologies. In its clinical application and quality assurance (QA) approach, the CyberKnife is currently situated somewhere in between stereotactic radiosurgery and radiotherapy. The clinical QA for this image-guided treatment delivery system typically follows the vendor's guidance, mainly because of the current lack of vendor-independent QA recommendations. The problem has been exacerbated because very little published data are available for QA for the CyberKnife system, especially for QA of the interaction between individual system components. The tools and techniques for QA of the CyberKnife are under development and will continue to improve with longer clinical experience of the users. The technology itself continues to evolve, forcing continuous changes and adaptation of QA. To aid in the process of developing comprehensive guidance on CyberKnife QA, a database of errors based on users reporting incidents and corrective actions would be desirable. The goal of this work was to discuss the status of QA guidelines in the clinical implementation of the CyberKnife system. This investigation was done from the perspective of an active clinical and research site using the CyberKnife.

  2. Combination effects of tissue heterogeneity and geometric targeting error in stereotactic body radiotherapy for lung cancer using CyberKnife.

    PubMed

    Kang, Ki Mun; Jeong, Bae Kwon; Choi, Hoon-Sik; Yoo, Seung Hoon; Hwang, Ui-Jung; Lim, Young Kyung; Jeong, Hojin

    2015-09-08

    We have investigated the combined effect of tissue heterogeneity and its variation associated with geometric error in stereotactic body radiotherapy (SBRT) for lung cancer. The treatment plans for eight lung cancer patients were calculated using effective path length (EPL) correction and Monte Carlo (MC) algorithms, with both having the same beam configuration for each patient. These two kinds of plans for individual patients were then subsequently recalculated with adding systematic and random geometric errors. In the ordinary treatment plans calculated with no geometric offset, the EPL calculations, compared with the MC calculations, largely overestimated the doses to PTV by ~ 21%, whereas the overestimation were markedly lower in GTV by ~ 12% due to relatively higher density of GTV than of PTV. When recalculating the plans for individual patients with assigning the systematic and random geometric errors, no significant changes in the relative dose distribution, except for overall shift, were observed in the EPL calculations, whereas largely altered in the MC calculations with a consistent increase in dose to GTV. Considering the better accuracy of MC than EPL algorithms, the present results demonstrated the strong coupling of tissue heterogeneity and geometric error, thereby emphasizing the essential need for simultaneous correction for tissue heterogeneity and geometric targeting error in SBRT of lung cancer.

  3. [CyberKnife can cause inappropriate shock].

    PubMed

    Cakmak, Nazmiye; Yılmaz, Hale; Sayar, Nurten; Erer, Betül

    2012-12-01

    Implantable cardioverter-defibrillators (ICD) have been increasingly used to treat life-threatening ventricular tachyarrhythmias. Although they have life-saving capabilities, they are very sensitive to electromagnetic energy sources. It has been reported that many problems associated with the detection of tachyarrhythmias and termination of the mechanism of the ICDs occur due to electromagnetic interference (EMI). In spite of the fact that EMI has been decreasingly observed with the latest generation ICDs, problems may still occur during radiotherapy. The CyberKnife is the latest stereotactic radio-surgery technology in the field of radiotherapy, and is currently being used for the treatment of malign neoplasm in the body. It is especially preferred for the treatment of advanced stage and metastatic tumors. Five ICD shocks were detected in a patient during a routine follow-up visit. When the patient was evaluated, it was determined that he underwent radiotherapy with CyberKnife technology because of lung metastasis and rectal adenocarcinoma. He received the ICD shocks while he was on radiotherapy. When the stored intracardiac electrograms in the memory of the ICD were investigated, it was established that the shocks were inappropriate shocks due to oversensing because of the exposure to EMI.

  4. Dose escalation of Stereotactic Body Radiotherapy (SBRT) for locally advanced unresectable pancreatic cancer patients with CyberKnife: protocol of a phase I study.

    PubMed

    Qing, Shui-Wang; Ju, Xiao-Ping; Cao, Yang-Sen; Zhang, Huo-Jun

    2017-01-09

    Dose escalation of SBRT for locally advanced pancreatic cancer patients had been reported in several studies in one or three fractions, and phase I protocol was developed to investigate the maximum tolerated dose with CyberKnife for locally advanced unresectable pancreatic cancer patients in five fractions. The study is designed as a mono-center phase I study. The primary endpoint is to determine the maximum tolerated dose by frequency of III/IV GI (gastrointestinal) toxicity. Adverse events (AE) according to Common Toxicity Criteria (CTC) version 4. Doses of 7 Gy, 7.5 Gy, 8 Gy, 8.5 Gy, 9 Gy, 9.5Gy x 5 respectively would be delivered while meeting with normal tissue constraints. A minimum of three patients will be included for each dosage level. And an interval is 4 weeks from the first patient treatment to the next patient treatment at each dose level. The maximal tolerated dose will be defined as the dose for which at least two patients in three, or at least three patients in nine, will present with a limiting toxicity. Since the dose and fractions of SBRT treatment for locally advanced pancreatic cancer patients are still unknown, we propose to conduct a Phase I study determining the maximum tolerated dose of CyberKnife SBRT for the treatment of locally advanced pancreatic tumor based on a 5 fractions treatment regimen. This trial protocol has been approved by the Ethics committee of Changhai hospital. The ethics number is 2016-030-01. Clinical trials number: NCT02716207 . Date of registration: 20 March 2016.

  5. Clinical application of CyberKnife for high-risk central nervous system tumors: A clinical trial report of 60 cases.

    PubMed

    Wang, Xin; Wang, Yuan-Yuan; Jiang, Peng; Ma, Jian-Jun; Qu, Zhen; Liu, Han-Chen; Wang, Shan-Shan; Wang, Yi-Shan

    2012-01-01

    The objective of the present study was to evaluate the application potential of CyberKnife for high-risk tumors of the central nervous system and to analyze the effectiveness of CyberKnife in relation to dose recovery and gain division (times). A total of Eighty-one targeted areas from 139 central nervous tumor lesions in 60 patients were treated with I-VI ranged CyberKnife for 1 week. Following CyberKnife treatment, imaging tests revealed a decrease in tumor volume, reduction of central nervous system symptoms and an increase in the life quality of patients. The advantages of CyberKnife include non-invasiveness, individualized treatment, flexibility, high accuracy and rapid treatment. CyberKnife produces slight damage and a favorable therapeutic effect and expands our concepts concerning precise radiotherapy for tumors. It is an indispensable method for personalized tumor treatment.

  6. Chest wall and rib irradiation and toxicities of early-stage lung cancer patients treated with CyberKnife stereotactic body radiotherapy.

    PubMed

    Podder, Tarun; Biswas, Tithi; Yao, Min; Zhang, Yuxia; Kim, Ellen; Ellis, Rodney J; Lo, Simon S; Machtay, Mitchell

    2014-12-01

    The aim of the study is to evaluate the chest wall and rib toxicities in primary lung cancer patients treated with CyberKnife-based stereotactic body radiotherapy. In this study, data were collected from the 118 patients, of which 25 patients who had longer follow-up (mean: 21.9 months) were considered. Studied parameters were maximum point dose, doses to 1-100 cm(3) of chest wall and 1-10 cm(3) of ribs. Three patients developed chest wall pain (grade I). 25 studied patients, on average, received 27.7 Gy to 30 cm(3) of chest wall and 50.4 Gy to 1 cm(3) of rib. Nine patients had more than 30 Gy dose to 30 cm(3) of chest wall. No rib bone fracture was found. No correlations of chest wall pain and volume of irradiation were found.

  7. Gated Volumetric-Modulated Arc Therapy vs. Tumor-Tracking CyberKnife Radiotherapy as Stereotactic Body Radiotherapy for Hepatocellular Carcinoma: A Dosimetric Comparison Study Focused on the Impact of Respiratory Motion Managements

    PubMed Central

    Yoon, KyoungJun; Kwak, Jungwon; Cho, Byungchul; Park, Jin-hong; Yoon, Sang Min; Lee, Sang-wook; Kim, Jong Hoon

    2016-01-01

    Purpose To assess the potential dosimetric benefits associated with the CyberKnife (CK) tumor tracking capability, wherein an extra margin for respiratory tumor motion is not required, when compared to respiratory-gated volumetric-modulated arc therapy (VMAT) for hepatocellular carcinoma (HCC). Methods Twenty-nine HCC patients previously treated with double-arc VMAT were enrolled. In each VMAT plan, the individual internal target volume (ITV) margin around the tumor was determined by measuring its motion over 30–70% of respiratory phases using four-dimensional computed tomography, followed by a 5-mm isotropic margin for the planning target volume (PTV). For each VMAT plan, two CK plans were generated using the original (CKoriginal, ITV included) and modified PTVs (CKmodified, ITV excluded) for comparison. In each case, the CKoriginal and CKmodified plans were compared to the original VMAT plan in terms of the dosimetric parameters including the conformity index (CI), PTV coverage (CO), organs at risk (OAR) doses, and normal liver tissue sparing. Results The original PTVs with median 24 cc (range, 9–65 cc) were significantly reduced to median 12 cc (range, 5–41 cc) in the CKmodified plans. Statistically significant differences in plan qualities were observed between the VMAT and the CK plans: mean CI, 1.05 in VMAT vs. 1.17 in both CK plans (p < 0.001); and mean CO, 93.0% in VMAT vs. 96.6% in CKoriginal and 96.9% in CKmodified (p < 0.001). The average volume of normal liver tissue receiving > 15 Gy was significantly decreased in the CKmodified plan, as compared to that in the VMAT and CKoriginal plans, by 1.75- and 1.61-fold, respectively. Conclusions The tumor tracking capability of the CK system can significantly decrease the volume of normal liver tissue receiving > 15 Gy, while maintaining high precision in target localization, conformity, tumor coverage, and dose sparing of the OAR. Therefore, it can be a valuable SBRT option, particularly for HCC patients

  8. CyberKnife therapy of 24 multiple brain metastases from lung cancer: A case report.

    PubMed

    Yang, Guiqing; Wang, Yishan; Wang, Yuanyuan; Lin, Sixiang; Sun, Dongning

    2013-08-01

    Brain metastasis is a significant cause of morbidity and mortality and a critical complication of non-central nervous system primary carcinoma. The present study describes the clinical case of a 46-year-old male with lung cancer and life-threatening brain metastases. The patient was diagnosed with lung cancer with a clinical stage of T2N0M1 (stage IV). Six months after the initial diagnosis and administration of conformal radiotherapy combined with three cycles of chemotherapy, an enhanced computed tomography (CT) scan of the brain revealed abnormalities with double-dosing of intravenous contrast. The CT scan identified >24 lesions scattered in the whole brain. The patient was treated with three-fraction Cyberknife radiotherapy at 22 Gy, delivered to the brain metastases at the Center for Tumor Treatment of People's Liberation Army 107th Hospital. Following CyberKnife therapy, a CT scan of the brain revealed that most of the tumors had disappeared with almost no residual traces. The stereotactic radiosurgery (SRS) conducted using CyberKnife, an image-guided frameless robotic technology for whole-body radiosurgery, had produced a marked response. The present case report demonstrates that CyberKnife therapy plays a significant role in the management of multiple meta-static brain tumors.

  9. Synchrony - Cyberknife Respiratory Compensation Technology

    SciTech Connect

    Ozhasoglu, Cihat Saw, Cheng B.; Chen Hungcheng; Burton, Steven; Komanduri, Krishna; Yue, Ning J.; Huq, Saiful M.; Heron, Dwight E.

    2008-07-01

    Studies of organs in the thorax and abdomen have shown that these organs can move as much as 40 mm due to respiratory motion. Without compensation for this motion during the course of external beam radiation therapy, the dose coverage to target may be compromised. On the other hand, if compensation of this motion is by expansion of the margin around the target, a significant volume of normal tissue may be unnecessarily irradiated. In hypofractionated regimens, the issue of respiratory compensation becomes an important factor and is critical in single-fraction extracranial radiosurgery applications. CyberKnife is an image-guided radiosurgery system that consists of a 6-MV LINAC mounted to a robotic arm coupled through a control loop to a digital diagnostic x-ray imaging system. The robotic arm can point the beam anywhere in space with 6 degrees of freedom, without being constrained to a conventional isocenter. The CyberKnife has been recently upgraded with a real-time respiratory tracking and compensation system called Synchrony. Using external markers in conjunction with diagnostic x-ray images, Synchrony helps guide the robotic arm to move the radiation beam in real time such that the beam always remains aligned with the target. With the aid of Synchrony, the tumor motion can be tracked in three-dimensional space, and the motion-induced dosimetric change to target can be minimized with a limited margin. The working principles, advantages, limitations, and our clinical experience with this new technology will be discussed.

  10. CyberKnife radiosurgery for brain metastases.

    PubMed

    Wowra, Berndt; Muacevic, Alexander; Tonn, Jörg-Christian

    2012-01-01

    Classic radiosurgery is a neurosurgical treatment concept for single-fraction irradiation of cerebral lesions not amenable to open surgery. Until recently it has been realized mainly by frame-based technologies (Gamma Knife; stereotactic linear accelerators). The CyberKnife described in 1997 is an image-guided frameless robotic technology for whole-body radiosurgery. It can be used for classic single-fraction radiosurgery and for hypofractionated treatments. The CyberKnife treatment procedure is completely non-invasive and can be repeated throughout the body if necessary. Brain metastases are an important and frequently treated indication of modern radiosurgery. Data concerning radiosurgical treatment of brain metastases with the CyberKnife are reviewed. Scientific evidence shows that the full-body applicability of the CyberKnife is not at the expense of an inferior intracranial treatment quality when compared to standard frame-based technology. The clinical results of CyberKnife single-fraction radiosurgery are in line with the published literature. The attractive therapeutic profile of CyberKnife radiosurgery is reflected by a high tumor control and a low toxicity and the repeatability of the treatments for recurrent metastases. Although hypofractionated treatments (in 3-5 fractions) of brain metastases have been performed with the CyberKnife to treat large metastases, the clinical significance of this new radiosurgical concept is unclear and requires further study. A new approach is to treat the resection cavity with radiosurgery after surgical removal of brain metastases. In this concept radiosurgery replaces fractionated radiation therapy as an adjunct to surgery. The initial results are very promising. The CyberKnife has been established as a modern non-invasive technology for intra- and extracranial radiosurgery. It adds to the oncological armamentarium and confers upon radiosurgery a greater emphasis as an oncological treatment concept.

  11. Short-term outcomes of CyberKnife therapy for advanced high-risk tumors: A report of 160 cases.

    PubMed

    Wang, Yi-Shan; Wang, Yuan-Yuan; Jiang, Peng; Ma, Jian-Jun; Qu, Zhen; Wang, Xi-Lin; Li, Jun-Ti; Jia, Xi-Feng

    2012-04-01

    The objective of the present study was to evaluate short-term outcomes of CyberKnife therapy in patients with advanced high-risk tumors. A total of 201 target areas from 341 advanced high-risk tumor lesions in 160 patients were treated with CyberKnife. A prescribed dose of 18-60 Gy to the gross tumor volume was delivered in 1-6 fractions to complete the entire treatment in 1 week. Radiographic studies and clinical examinations were performed at 1- to 3-month follow-up intervals, and the results were compared to outcomes of 160 similar advanced high-risk tumor patients who were treated by conformal radiotherapy (CRT). After CyberKnife therapy, the short-term improvement in the quality of life was significant according to radiographic study, radioimmunoassay and ZPS scores of these patients. The total rates of objective efficacy and alleviation of ascities were as high as 66.88 and 67.90%. The short-term outcomes in our series of patients with advanced high-risk tumors treated with CyberKnife appeared to be better compared to conventional CRT. CyberKnife may be an option for patients with incurable advanced high-risk tumors, although further studies of the long-term outcomes are required to confirm the validity.

  12. Fractionated stereotactic radiosurgery for vestibular schwannomas using cyberknife: A single institution experience.

    PubMed

    Kocak, Mihriban Erdogan; Sengul, Adem; Ekici, Kemal; Olmezoglu, Ali; Seseogullari, Ozgur

    2016-09-01

    To assess tumour control, hearing preservation status, and complication ratio after fractionated stereotactic radiosurgery/radiotherapy by using CyberKnife device in patients with vestibular schwannomas. This retrospective study was conducted at Izmir Ataturk Research and Tranining Hospital, Turkey, and comprised data of vestibular schwannomas patients treated with stereotactic radiosurgery/radiotherapy from March 2010 to December 2013. The patients were subjected to a dose ranging from 12 to 30Gy using CyberKnife system with an average of three fractions. SPSS 17 was used for data analysis. Paired t-test and Pearson's chi-square test were used to compare clinical parameters between groups. P<0.05 was considered significant. Of the 41 patients, 26(63.4%) were women and 15(36.6%) were men. The median follow-up duration after stereotactic radiosurgery/radiotherapy was 25 months (interquartile range: 9-44 months). Radiographic control evaluation ratio was 95.7% with a median follow-up of 3 years (IQR: 18.5 months). Results of 23(56%) patients showed stabile response, 17(42%) regression response and 1(2%) progression response. There were no statistically significant changes between pre- and post-stereotactic radiosurgery/radiotherapy symptoms (p>0.05). One (2.4%) patient reported new onset facial paresis. Stereotactic radiosurgery/radiotherapy treatment of vestibular schwannomas resulted in a good ratio of tumour control. Hearing preservation status and ratios of toxicity were comparable to published literature.

  13. Peripheral doses in CyberKnife radiosurgery

    SciTech Connect

    Petti, Paula L.; Chuang, Cynthia F.; Smith, Vernon; Larson, David A.

    2006-06-15

    The purpose of this work is to measure the dose outside the treatment field for conformal CyberKnife treatments, to compare the results to those obtained for similar treatments delivered with gamma knife or intensity-modulated radiation therapy (IMRT), and to investigate the sources of peripheral dose in CyberKnife radiosurgery. CyberKnife treatment plans were developed for two hypothetical lesions in an anthropomorphic phantom, one in the thorax and another in the brain, and measurements were made with LiF thermoluminescent dosimeters (TLD-100 capsules) placed within the phantom at various depths and distances from the irradiated volume. For the brain lesion, gamma knife and 6-MV IMRT treatment plans were also developed, and peripheral doses were measured at the same locations as for the CyberKnife plan. The relative contribution to the CyberKnife peripheral dose from inferior- or superior-oblique beams entering or exiting through the body, internally scattered radiation, and leakage radiation was assessed through additional experiments using the single-isocenter option of the CyberKnife treatment-planning program with different size collimators. CyberKnife peripheral doses (in cGy) ranged from 0.16 to 0.041 % ({+-}0.003%) of the delivered number of monitor units (MU) at distances between 18 and 71 cm from the field edge. These values are two to five times larger than those measured for the comparable gamma knife brain treatment, and up to a factor of four times larger those measured in the IMRT experiment. Our results indicate that the CyberKnife peripheral dose is due largely to leakage radiation, however at distances less than 40 cm from the field edge, entrance, or exit dose from inferior- or superior-oblique beams can also contribute significantly. For distances larger than 40 cm from the field edge, the CyberKnife peripheral dose is directly related to the number of MU delivered, since leakage radiation is the dominant component.

  14. Trigeminal neuralgia treatment dosimetry of the Cyberknife

    SciTech Connect

    Ho, Anthony; Lo, Anthony T.; Dieterich, Sonja; Soltys, Scott G.; Gibbs, Iris C.; Chang, Steve G.; Adler, John R.

    2012-04-01

    There are 2 Cyberknife units at Stanford University. The robot of 1 Cyberknife is positioned on the patient's right, whereas the second is on the patient's left. The present study examines whether there is any difference in dosimetry when we are treating patients with trigeminal neuralgia when the target is on the right side or the left side of the patient. In addition, we also study whether Monte Carlo dose calculation has any effect on the dosimetry. We concluded that the clinical and dosimetric outcomes of CyberKnife treatment for trigeminal neuralgia are independent of the robot position. Monte Carlo calculation algorithm may be useful in deriving the dose necessary for trigeminal neuralgia treatments.

  15. 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.

  16. Experience with the CyberKnife for intracranial stereotactic radiosurgery: Analysis of dosimetry indices

    SciTech Connect

    Floriano, Alejandro Santa-Olalla, Iciar; Sanchez-Reyes, Alberto

    2014-04-01

    We evaluated coverage, dose homogeneity, dose conformity, and dose gradient in CyberKnife VSI treatment plans. Several dosimetric indices were calculated, and the results were compared with those of previous publications. The effect of target volume on the radiosurgical treatment indices selected was also investigated. The study population comprised the first 40 patients treated at our department from March 2011 to September 2012. Dosimetric indices were calculated and compared with published results for other frame-based and frameless intracranial stereotactic radiotherapy techniques. A comparison of the indices confirmed the ability of the CyberKnife VSI system to provide very high-quality dosing plans. The results were independent of target volume for coverage, homogeneity, and dose conformity. However, a dependence on target volume was observed for the dose-gradient indices analyzed. Based on the indices proposed, CyberKnife provides very good treatment plans and compares favorably with other techniques in most cases. However, greater consensus on the radiosurgery indices calculated would be desirable to facilitate comparison of the various techniques or the same techniques when applied by different users.

  17. Experience with the CyberKnife for intracranial stereotactic radiosurgery: analysis of dosimetry indices.

    PubMed

    Floriano, Alejandro; Santa-Olalla, Iciar; Sanchez-Reyes, Alberto

    2014-01-01

    We evaluated coverage, dose homogeneity, dose conformity, and dose gradient in CyberKnife VSI treatment plans. Several dosimetric indices were calculated, and the results were compared with those of previous publications. The effect of target volume on the radiosurgical treatment indices selected was also investigated. The study population comprised the first 40 patients treated at our department from March 2011 to September 2012. Dosimetric indices were calculated and compared with published results for other frame-based and frameless intracranial stereotactic radiotherapy techniques. A comparison of the indices confirmed the ability of the CyberKnife VSI system to provide very high-quality dosing plans. The results were independent of target volume for coverage, homogeneity, and dose conformity. However, a dependence on target volume was observed for the dose-gradient indices analyzed. Based on the indices proposed, CyberKnife provides very good treatment plans and compares favorably with other techniques in most cases. However, greater consensus on the radiosurgery indices calculated would be desirable to facilitate comparison of the various techniques or the same techniques when applied by different users.

  18. Treatment of hepatic metastases of colorectal cancer by robotic stereotactic radiation (Cyberknife ®).

    PubMed

    Peiffert, D; Baumann, A-S; Marchesi, V

    2014-04-01

    Cyberknife(®) is a dedicated stereotactic radiotherapy device. This new technology permits precise delivery of high dose gradient radiation therapy while sparing the surrounding organs at risk. Hepatic metastases of colorectal cancer (HMCRC) are an example of a lesion where treatment with Cyberknife(®) is indicated because they are located in a radio-sensitive organ and curative treatment is based on focal eradication (resection, radiofrequency ablation,...). The local control rate at one year is reported to be 70 to 100% depending on the study. Tolerance is excellent with less than a 5% rate of acute grade 3 or 4 side effects (nausea, vomiting, gastro-duodenal ulcer). The specific hepatotoxicity of radiotherapy, so-called radiation-induced liver disease (RILD), was found in only one study. Candidates for stereotactic radiotherapy are patients in whom disease is controlled except for intrahepatic disease with 1-3 hepatic metastases ≤ 6 cm in size who have contraindications for surgery, a WHO stage ≤ 2, a volume of healthy liver ≥ 700 cm(3) and normal liver function. It is actually a very simple treatment that results in very good local control with few contraindications. Its place in the management strategy of liver metastases needs further clarification.

  19. Comparison of dose distributions calculated by the cyberknife Monte Carlo and ray tracing algorithms for lung tumors: a phantom study

    NASA Astrophysics Data System (ADS)

    Koksal, Canan; Akbas, Ugur; Okutan, Murat; Demir, Bayram; Hakki Sarpun, Ismail

    2015-07-01

    Commercial treatment planning systems with have different dose calculation algorithms have been developed for radiotherapy plans. The Ray Tracing and the Monte Carlo dose calculation algorithms are available for MultiPlan treatment planning system. Many studies indicated that the Monte Carlo algorithm enables the more accurate dose distributions in heterogeneous regions such a lung than the Ray Tracing algorithm. The purpose of this study was to compare the Ray Tracing algorithm with the Monte Carlo algorithm for lung tumors in CyberKnife System. An Alderson Rando anthropomorphic phantom was used for creating CyberKnife treatment plans. The treatment plan was developed using the Ray Tracing algorithm. Then, this plan was recalculated with the Monte Carlo algorithm. EBT3 radiochromic films were put in the phantom to obtain measured dose distributions. The calculated doses were compared with the measured doses. The Monte Carlo algorithm is the more accurate dose calculation method than the Ray Tracing algorithm in nonhomogeneous structures.

  20. [CyberKnife radiosurgery--present status and future prospect].

    PubMed

    Nomura, Ryutaro; Suzuki, Ichiro

    2011-03-01

    The CyberKnife Robotic Radiosurgery System is a non-invasive alternative to surgery for the treatment of both cancerous and non-cancerous tumors anywhere in the body, including the prostate, lung, brain, spine, liver, pancreas, and kidney. The treatment, which involves the delivery of high doses of radiation to tumors with extreme accuracy, offers new hope to patients who have inoperable or surgically complex tumors or who may prefer a nonsurgical option. To date, more than 95,000 patients have been treated and more than 207 systems have been installed worldwide. The CyberKnife System is a one-of-a-kind device because of the following reasons. First, the CyberKnife System uses image guidance software to track and continually adjust treatment for any patient or tumor movement. This advantage places the system far ahead of other similar treatments. It allows patients to breathe normally and relax comfortably during treatment. Second, some forms of radiosurgery require rigid head frames that are screwed into the patient's skull in order to minimize any head movement. The CyberKnife System does not require such extreme procedures to maintain the head position; instead, it relies on the sophisticated tracking software, allowing for a much more comfortable and noninvasive treatment. Third, unlike some radiosurgery systems, which can only treat tumors in the head, the CyberKnife System has unlimited reach to treat a broad range of tumors throughout the body, including the prostate, lung, brain, spine, liver, pancreas, and kidney. Finally, the CyberKnife System's treatment accuracy is unrivaled. Its ability to treat tumors with supreme accuracy is noncomparable to that of other radiation therapy and radiosurgery systems. The CyberKnife System can essentially "paint" the tumor with radiation, allowing it to precisely deliver treatment to the tumor alone, sparing surrounding healthy tissue.

  1. Establishing a process of irradiating small animal brain using a CyberKnife and a microCT scanner.

    PubMed

    Kim, Haksoo; Fabien, Jeffrey; Zheng, Yiran; Yuan, Jake; Brindle, James; Sloan, Andrew; Yao, Min; Lo, Simon; Wessels, Barry; Machtay, Mitchell; Welford, Scott; Sohn, Jason W

    2014-02-01

    Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images. These experiments consisted of four parts: (1) building a mouse phantom for intensity modulated radiotherapy (IMRT) quality assurance (QA), (2) proving usability of a microCT for treatment planning, (3) fabricating a small animal positioning system for use with the CyberKnife's image guided radiotherapy (IGRT) system, and (4)in vivo verification of targeting accuracy. A set of solid water mouse phantoms was designed and fabricated, with radiochromic films (RCF) positioned in selected planes to measure delivered doses. After down-sampling for treatment planning compatibility, a CT image set of a phantom was imported into the CyberKnife treatment planning system--MultiPlan (ver. 3.5.2). A 0.5 cm diameter sphere was contoured within the phantom to represent a hemispherical section of a mouse brain. A nude mouse was scanned in an alpha cradle using a microCT scanner (cone-beam, 157 × 149 pixels slices, 0.2 mm longitudinal slice thickness). Based on the results of our positional accuracy study, a planning treatment volume (PTV) was created. A stereotactic body mold of the mouse was "printed" using a 3D printer laying UV curable acrylic plastic. Printer instructions were based on exported contours of the mouse's skin. Positional reproducibility in the mold was checked by measuring ten CT scans. To verify accurate dose delivery in vivo, six mice were irradiated in the mold with a 4 mm target contour and a 2 mm PTV margin to 3 Gy and sacrificed within 20 min to avoid DNA repair. The brain was sliced and stained for analysis. For the IMRT QA using a set of phantoms, the planned dose (6 Gy to the calculation point) was compared to the delivered dose measured via film and analyzed using Gamma analysis (3% and 3 mm). A passing rate of 99% was measured in

  2. Establishing a process of irradiating small animal brain using a CyberKnife and a microCT scanner

    SciTech Connect

    Kim, Haksoo; Welford, Scott; Fabien, Jeffrey; Zheng, Yiran; Yuan, Jake; Brindle, James; Yao, Min; Lo, Simon; Wessels, Barry; Machtay, Mitchell; Sohn, Jason W.; Sloan, Andrew

    2014-02-15

    Purpose: Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images. Methods: These experiments consisted of four parts: (1) building a mouse phantom for intensity modulated radiotherapy (IMRT) quality assurance (QA), (2) proving usability of a microCT for treatment planning, (3) fabricating a small animal positioning system for use with the CyberKnife's image guided radiotherapy (IGRT) system, and (4)in vivo verification of targeting accuracy. A set of solid water mouse phantoms was designed and fabricated, with radiochromic films (RCF) positioned in selected planes to measure delivered doses. After down-sampling for treatment planning compatibility, a CT image set of a phantom was imported into the CyberKnife treatment planning system—MultiPlan (ver. 3.5.2). A 0.5 cm diameter sphere was contoured within the phantom to represent a hemispherical section of a mouse brain. A nude mouse was scanned in an alpha cradle using a microCT scanner (cone-beam, 157 × 149 pixels slices, 0.2 mm longitudinal slice thickness). Based on the results of our positional accuracy study, a planning treatment volume (PTV) was created. A stereotactic body mold of the mouse was “printed” using a 3D printer laying UV curable acrylic plastic. Printer instructions were based on exported contours of the mouse's skin. Positional reproducibility in the mold was checked by measuring ten CT scans. To verify accurate dose delivery in vivo, six mice were irradiated in the mold with a 4 mm target contour and a 2 mm PTV margin to 3 Gy and sacrificed within 20 min to avoid DNA repair. The brain was sliced and stained for analysis. Results: For the IMRT QA using a set of phantoms, the planned dose (6 Gy to the calculation point) was compared to the delivered dose measured via film and analyzed using Gamma analysis (3% and 3 mm). A

  3. Establishing a process of irradiating small animal brain using a CyberKnife and a microCT scanner

    SciTech Connect

    Kim, Haksoo; Welford, Scott; Fabien, Jeffrey; Zheng, Yiran; Yuan, Jake; Brindle, James; Yao, Min; Lo, Simon; Wessels, Barry; Machtay, Mitchell; Sohn, Jason W.; Sloan, Andrew

    2014-02-15

    Purpose: Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images. Methods: These experiments consisted of four parts: (1) building a mouse phantom for intensity modulated radiotherapy (IMRT) quality assurance (QA), (2) proving usability of a microCT for treatment planning, (3) fabricating a small animal positioning system for use with the CyberKnife's image guided radiotherapy (IGRT) system, and (4)in vivo verification of targeting accuracy. A set of solid water mouse phantoms was designed and fabricated, with radiochromic films (RCF) positioned in selected planes to measure delivered doses. After down-sampling for treatment planning compatibility, a CT image set of a phantom was imported into the CyberKnife treatment planning system—MultiPlan (ver. 3.5.2). A 0.5 cm diameter sphere was contoured within the phantom to represent a hemispherical section of a mouse brain. A nude mouse was scanned in an alpha cradle using a microCT scanner (cone-beam, 157 × 149 pixels slices, 0.2 mm longitudinal slice thickness). Based on the results of our positional accuracy study, a planning treatment volume (PTV) was created. A stereotactic body mold of the mouse was “printed” using a 3D printer laying UV curable acrylic plastic. Printer instructions were based on exported contours of the mouse's skin. Positional reproducibility in the mold was checked by measuring ten CT scans. To verify accurate dose delivery in vivo, six mice were irradiated in the mold with a 4 mm target contour and a 2 mm PTV margin to 3 Gy and sacrificed within 20 min to avoid DNA repair. The brain was sliced and stained for analysis. Results: For the IMRT QA using a set of phantoms, the planned dose (6 Gy to the calculation point) was compared to the delivered dose measured via film and analyzed using Gamma analysis (3% and 3 mm). A

  4. Cyberknife treatment for low and intermediate risk prostate cancer.

    PubMed

    Detti, B; Bonomo, P; Masi, L; Doro, R; Cipressi, S; Iermano, C; Bonucci, I; Franceschini, D; Di Cataldo, V; Di Brina, L; Baki, M; Simontacchi, G; Meattini, I; Carini, M; Serni, S; Nicita, G; Livi, L

    2015-05-01

    Cyberknife is an emerging treatment for early stage prostate cancer. Between October 2012 and January 2014, 32 patients were treated in our institution. Prescribed dose was 35-36.25 Gy in five fractions. Biochemical response was observed in 22 patients. Four patients experienced G2 acute genitourinary toxicity and in two cases we recorded G3 acute GU toxicity. 5 patients experienced G2 acute proctitis. At last follow up visit, all patients were still alive. 29 remained free of disease at last follow up appointment, while three developed a biochemical recurrence. Our experience confirms the efficacy and safety of Cyberknife for localized prostate cancer.

  5. CyberKnife Boost for Patients with Cervical Cancer Unable to Undergo Brachytherapy.

    PubMed

    Haas, Jonathan Andrew; Witten, Matthew R; Clancey, Owen; Episcopia, Karen; Accordino, Diane; Chalas, Eva

    2012-01-01

    Standard radiation therapy for patients undergoing primary chemosensitized radiation for carcinomas of the cervix usually consists of external beam radiation followed by an intracavitary brachytherapy boost. On occasion, the brachytherapy boost cannot be performed due to unfavorable anatomy or because of coexisting medical conditions. We examined the safety and efficacy of using CyberKnife stereotactic body radiotherapy (SBRT) as a boost to the cervix after external beam radiation in those patients unable to have brachytherapy to give a more effective dose to the cervix than with conventional external beam radiation alone. Six consecutive patients with anatomic or medical conditions precluding a tandem and ovoid boost were treated with combined external beam radiation and CyberKnife boost to the cervix. Five patients received 45 Gy to the pelvis with serial intensity-modulated radiation therapy boost to the uterus and cervix to a dose of 61.2 Gy. These five patients received an SBRT boost to the cervix to a dose of 20 Gy in five fractions of 4 Gy each. One patient was treated to the pelvis to a dose of 45 Gy with an external beam boost to the uterus and cervix to a dose of 50.4 Gy. This patient received an SBRT boost to the cervix to a dose of 19.5 Gy in three fractions of 6.5 Gy. Five percent volumes of the bladder and rectum were kept to ≤75 Gy in all patients (i.e., V75 Gy ≤ 5%). All of the patients remain locally controlled with no evidence of disease following treatment. Grade 1 diarrhea occurred in 4/6 patients during the conventional external beam radiation. There has been no grade 3 or 4 rectal or bladder toxicity. There were no toxicities observed following SBRT boost. At a median follow-up of 14 months, CyberKnife radiosurgical boost is well tolerated and efficacious in providing a boost to patients with cervix cancer who are unable to undergo brachytherapy boost. Further follow-up is required to see if these results remain

  6. Dosimetric Comparison Between 3-Dimensional Conformal and Robotic SBRT Treatment Plans for Accelerated Partial Breast Radiotherapy.

    PubMed

    Goggin, L M; Descovich, M; McGuinness, C; Shiao, S; Pouliot, J; Park, C

    2016-06-01

    Accelerated partial breast irradiation is an attractive alternative to conventional whole breast radiotherapy for selected patients. Recently, CyberKnife has emerged as a possible alternative to conventional techniques for accelerated partial breast irradiation. In this retrospective study, we present a dosimetric comparison between 3-dimensional conformal radiotherapy plans and CyberKnife plans using circular (Iris) and multi-leaf collimators. Nine patients who had undergone breast-conserving surgery followed by whole breast radiation were included in this retrospective study. The CyberKnife planning target volume (PTV) was defined as the lumpectomy cavity + 10 mm + 2 mm with prescription dose of 30 Gy in 5 fractions. Two sets of 3-dimensional conformal radiotherapy plans were created, one used the same definitions as described for CyberKnife and the second used the RTOG-0413 definition of the PTV: lumpectomy cavity + 15 mm + 10 mm with prescription dose of 38.5 Gy in 10 fractions. Using both PTV definitions allowed us to compare the dose delivery capabilities of each technology and to evaluate the advantage of CyberKnife tracking. For the dosimetric comparison using the same PTV margins, CyberKnife and 3-dimensional plans resulted in similar tumor coverage and dose to critical structures, with the exception of the lung V5%, which was significantly smaller for 3-dimensional conformal radiotherapy, 6.2% when compared to 39.4% for CyberKnife-Iris and 17.9% for CyberKnife-multi-leaf collimator. When the inability of 3-dimensional conformal radiotherapy to track motion is considered, the result increased to 25.6%. Both CyberKnife-Iris and CyberKnife-multi-leaf collimator plans demonstrated significantly lower average ipsilateral breast V50% (25.5% and 24.2%, respectively) than 3-dimensional conformal radiotherapy (56.2%). The CyberKnife plans were more conformal but less homogeneous than the 3-dimensional conformal radiotherapy plans. Approximately 50% shorter

  7. Implementation of Monte Carlo Dose calculation for CyberKnife treatment planning

    NASA Astrophysics Data System (ADS)

    Ma, C.-M.; Li, J. S.; Deng, J.; Fan, J.

    2008-02-01

    Accurate dose calculation is essential to advanced stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) especially for treatment planning involving heterogeneous patient anatomy. This paper describes the implementation of a fast Monte Carlo dose calculation algorithm in SRS/SRT treatment planning for the CyberKnife® SRS/SRT system. A superposition Monte Carlo algorithm is developed for this application. Photon mean free paths and interaction types for different materials and energies as well as the tracks of secondary electrons are pre-simulated using the MCSIM system. Photon interaction forcing and splitting are applied to the source photons in the patient calculation and the pre-simulated electron tracks are repeated with proper corrections based on the tissue density and electron stopping powers. Electron energy is deposited along the tracks and accumulated in the simulation geometry. Scattered and bremsstrahlung photons are transported, after applying the Russian roulette technique, in the same way as the primary photons. Dose calculations are compared with full Monte Carlo simulations performed using EGS4/MCSIM and the CyberKnife treatment planning system (TPS) for lung, head & neck and liver treatments. Comparisons with full Monte Carlo simulations show excellent agreement (within 0.5%). More than 10% differences in the target dose are found between Monte Carlo simulations and the CyberKnife TPS for SRS/SRT lung treatment while negligible differences are shown in head and neck and liver for the cases investigated. The calculation time using our superposition Monte Carlo algorithm is reduced up to 62 times (46 times on average for 10 typical clinical cases) compared to full Monte Carlo simulations. SRS/SRT dose distributions calculated by simple dose algorithms may be significantly overestimated for small lung target volumes, which can be improved by accurate Monte Carlo dose calculations.

  8. Feasibility Study on Applying Radiophotoluminescent Glass Dosimeters for CyberKnife SRS Dose Verification

    PubMed Central

    Hsu, Shih-Ming; Hung, Chao-Hsiung; Liao, Yi-Jen; Fu, Hsiao-Mei; Tsai, Jo-Ting

    2017-01-01

    CyberKnife is one of multiple modalities for stereotactic radiosurgery (SRS). Due to the nature of CyberKnife and the characteristics of SRS, dose evaluation of the CyberKnife procedure is critical. A radiophotoluminescent glass dosimeter was used to verify the dose accuracy for the CyberKnife procedure and validate a viable dose verification system for CyberKnife treatment. A radiophotoluminescent glass dosimeter, thermoluminescent dosimeter, and Kodak EDR2 film were used to measure the lateral dose profile and percent depth dose of CyberKnife. A Monte Carlo simulation for dose verification was performed using BEAMnrc to verify the measured results. This study also used a radiophotoluminescent glass dosimeter coupled with an anthropomorphic phantom to evaluate the accuracy of the dose given by CyberKnife. Measurements from the radiophotoluminescent glass dosimeter were compared with the results of a thermoluminescent dosimeter and EDR2 film, and the differences found were less than 5%. The radiophotoluminescent glass dosimeter has some advantages in terms of dose measurements over CyberKnife, such as repeatability, stability, and small effective size. These advantages make radiophotoluminescent glass dosimeters a potential candidate dosimeter for the CyberKnife procedure. This study concludes that radiophotoluminescent glass dosimeters are a promising and reliable dosimeter for CyberKnife dose verification with clinically acceptable accuracy within 5%. PMID:28046056

  9. Feasibility Study on Applying Radiophotoluminescent Glass Dosimeters for CyberKnife SRS Dose Verification.

    PubMed

    Hsu, Shih-Ming; Hung, Chao-Hsiung; Liao, Yi-Jen; Fu, Hsiao-Mei; Tsai, Jo-Ting; Huang, Yung-Hui; Huang, David Y C

    2017-01-01

    CyberKnife is one of multiple modalities for stereotactic radiosurgery (SRS). Due to the nature of CyberKnife and the characteristics of SRS, dose evaluation of the CyberKnife procedure is critical. A radiophotoluminescent glass dosimeter was used to verify the dose accuracy for the CyberKnife procedure and validate a viable dose verification system for CyberKnife treatment. A radiophotoluminescent glass dosimeter, thermoluminescent dosimeter, and Kodak EDR2 film were used to measure the lateral dose profile and percent depth dose of CyberKnife. A Monte Carlo simulation for dose verification was performed using BEAMnrc to verify the measured results. This study also used a radiophotoluminescent glass dosimeter coupled with an anthropomorphic phantom to evaluate the accuracy of the dose given by CyberKnife. Measurements from the radiophotoluminescent glass dosimeter were compared with the results of a thermoluminescent dosimeter and EDR2 film, and the differences found were less than 5%. The radiophotoluminescent glass dosimeter has some advantages in terms of dose measurements over CyberKnife, such as repeatability, stability, and small effective size. These advantages make radiophotoluminescent glass dosimeters a potential candidate dosimeter for the CyberKnife procedure. This study concludes that radiophotoluminescent glass dosimeters are a promising and reliable dosimeter for CyberKnife dose verification with clinically acceptable accuracy within 5%.

  10. Electromagnetic tracker accuracy in the CyberKnife suite

    NASA Astrophysics Data System (ADS)

    Wilson, Emmanuel; Slack, Rebecca; Banovac, Filip; Dieterich, Sonja; Zhang, Hui; Cleary, Kevin

    2006-03-01

    Electromagnetic trackers have found inroads into medical applications as a tool for navigation in recent years. Their susceptibility to interference from both electromagnetic and ferromagnetic sources have prompted several accuracy assessment studies in past years. To the best of our knowledge, this is the first accuracy study conducted to characterize measurement accuracy of an NDI AURORA electromagnetic tracker within a CyberKnife radiosurgery suite. CyberKnife is a frameless, stereotactic radiosurgery device used to ablate tumors within the brain, spine and in recent years, the chest and abdomen. This paper uses a data collection protocol to collect uniformly distributed data points within a subset of the AURORA measurement volume in a CyberKnife suite. The key aim of the study is to determine the extent to which large metal components of the CyberKnife stereotactic radiosurgery device and robot mount contribute to overall system performance for the AURORA electromagnetic device. A secondary goal of the work is to determine the variation in accuracy and device behavior with the presence of ionizing radiation when the LINAC is turned on.

  11. CyberKnife radiosurgery for the treatment of orbital metastases.

    PubMed

    Klingenstein, A; Kufeld, M; Wowra, B; Muacevic, A; Fürweger, C; Schaller, U C

    2012-10-01

    Purpose of this study is to evaluate radiographic therapy response, clinical outcome and adverse effects of CyberKnife radiosurgery in patients suffering from orbital metastases. Sixteen orbital metastases originating from different solid cancers in fourteen patients were treated by single fraction CyberKnife radiosurgery. Radiographic response and clinical outcome were evaluated. The treated tumor volume ranged from 0.2 to 35 cm3 (median 2.3 cm3, mean 7.0 cm3, SD 6 10.4 cm3, CI 0.9-9.4 cm3). The prescription dose ranged from 16.5-21 Gy (median 18 Gy, mean 18.2 Gy, SD 6 1.2 Gy, CI 17.0-18.4 Gy). A no change situation was observed in nine lesions, partial remission in four as well as complete remission in one metastasis. Tumor growth was stabilized or regressive following CyberKnife therapy in 87% of the cases. Recurrence was observed in two cases (13%). Before therapy, three patients suffered from visual disturbance and five patients reported diplopia. Six patients had no initial symptoms. After therapy, one patient indicated improvement of the present visual deficit and two patients no change. Out of the two patients with persistent diplopia, two reported improvement after therapy and three no change. No progression of symptoms was noted in any of the cases. Fourteen out of sixteen treated lesions were stable or regressive following CyberKnife radiosurgery (87%). As no serious adverse effects were reported in this series, CyberKnife therapy was shown to be of great value for local management of orbital metastases.

  12. 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.

  13. Monte Carlo study of a Cyberknife stereotactic radiosurgery system

    SciTech Connect

    Araki, Fujio

    2006-08-15

    This study investigated small-field dosimetry for a Cyberknife stereotactic radiosurgery system using Monte Carlo simulations. The EGSnrc/BEAMnrc Monte Carlo code was used to simulate the Cyberknife treatment head, and the DOSXYZnrc code was implemented to calculate central axis depth-dose curves, off-axis dose profiles, and relative output factors for various circular collimator sizes of 5 to 60 mm. Water-to-air stopping power ratios necessary for clinical reference dosimetry of the Cyberknife system were also evaluated by Monte Carlo simulations. Additionally, a beam quality conversion factor, k{sub Q}, for the Cyberknife system was evaluated for cylindrical ion chambers with different wall material. The accuracy of the simulated beam was validated by agreement within 2% between the Monte Carlo calculated and measured central axis depth-dose curves and off-axis dose profiles. The calculated output factors were compared with those measured by a diode detector and an ion chamber in water. The diode output factors agreed within 1% with the calculated values down to a 10 mm collimator. The output factors with the ion chamber decreased rapidly for collimators below 20 mm. These results were confirmed by the comparison to those from Monte Carlo methods with voxel sizes and materials corresponding to both detectors. It was demonstrated that the discrepancy in the 5 and 7.5 mm collimators for the diode detector is due to the water nonequivalence of the silicon material, and the dose fall-off for the ion chamber is due to its large active volume against collimators below 20 mm. The calculated stopping power ratios of the 60 mm collimator from the Cyberknife system (without a flattening filter) agreed within 0.2% with those of a 10x10 cm{sup 2} field from a conventional linear accelerator with a heavy flattening filter and the incident electron energy, 6 MeV. The difference in the stopping power ratios between 5 and 60 mm collimators was within 0.5% at a 10 cm depth in

  14. Performance of a Motion Tracking System During Cyberknife Robotic Radiosurgery

    NASA Astrophysics Data System (ADS)

    Cavedon, Carlo; Francescon, Paolo; Cora, Stefania; Moschini, Giuliano; Rossi, Paolo

    2009-03-01

    Cyberknife (Accuracy Inc., Ca) is a robotic radio-surgery system that includes a compact 6 MV linac delivering up to 800 cGy per minute, and an automate arm to aim at any part of the body from any angle. An essential tool is the guidance system based on x-ray imaging cameras located on supports around the patient. A Cyberknife system has been operational at the Vicenza (Italy) Hospital for years and is mainly employed for treating benign and malignant tumors, and Arterior-Venous Malformations. In radiation therapy, delivery of high doses to targets that move with respiration is challenging because of possible spatial inaccuracies. The purpose of this work was to estimate the accuracy of the prediction algorithm used to compensate for system latency in a real-time respiratory tracking system. We have analyzed respiratory signals of 30 patients who had lung or liver Cyberknife treatments. The "Synchrony" (Accuracy Inc.) motion tracking system we use is based on the correlation between the position of LED markers, detected in real time, and the position of internal markers, sampled through x-ray imaging. The position of the external LED signals, though read in real time, must be predicted to compensate for a few hundred ms time lag in the feedback loop that redirects the beam to the current target position. The respiratory signals were described by employing their frequency power spectrum, as recently proposed by other authors. Prediction errors above 1.5 mm, lasting for periods longer than 5 seconds were observed for irregular breathers. These episodes correlate to the presence of a bimodal distribution in the power spectral density, and of very low frequencies contribution. A more refined approach would include a personalized choice of the prediction algorithm based on the very first minutes of treatment. Patient training aimed at reducing breathing irregularities might also result in improved spatial accuracy.

  15. Performance of a Motion Tracking System During Cyberknife Robotic Radiosurgery

    SciTech Connect

    Cavedon, Carlo; Francescon, Paolo; Cora, Stefania; Moschini, Giuliano; Rossi, Paolo

    2009-03-10

    Cyberknife (Accuracy Inc., Ca) is a robotic radio-surgery system that includes a compact 6 MV linac delivering up to 800 cGy per minute, and an automate arm to aim at any part of the body from any angle. An essential tool is the guidance system based on x-ray imaging cameras located on supports around the patient. A Cyberknife system has been operational at the Vicenza (Italy) Hospital for years and is mainly employed for treating benign and malignant tumors, and Arterior-Venous Malformations. In radiation therapy, delivery of high doses to targets that move with respiration is challenging because of possible spatial inaccuracies. The purpose of this work was to estimate the accuracy of the prediction algorithm used to compensate for system latency in a real-time respiratory tracking system. We have analyzed respiratory signals of 30 patients who had lung or liver Cyberknife treatments. The 'Synchrony'(Accuracy Inc.) motion tracking system we use is based on the correlation between the position of LED markers, detected in real time, and the position of internal markers, sampled through x-ray imaging. The position of the external LED signals, though read in real time, must be predicted to compensate for a few hundred ms time lag in the feedback loop that redirects the beam to the current target position. The respiratory signals were described by employing their frequency power spectrum, as recently proposed by other authors. Prediction errors above 1.5 mm, lasting for periods longer than 5 seconds were observed for irregular breathers. These episodes correlate to the presence of a bimodal distribution in the power spectral density, and of very low frequencies contribution. A more refined approach would include a personalized choice of the prediction algorithm based on the very first minutes of treatment. Patient training aimed at reducing breathing irregularities might also result in improved spatial accuracy.

  16. 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.

  17. Surgical strategies for managing foraminal nerve sheath tumors: the emerging role of CyberKnife ablation

    PubMed Central

    Murovic, Judith A.; Charles Cho, S.

    2009-01-01

    Sixteen Stanford University Medical Center (SUMC) patients with foraminal nerve sheath tumors had charts reviewed. CyberKnife radiosurgery was innovative in management. Parameters were evaluated for 16 foraminal nerve sheath tumors undergoing surgery, some with CyberKnife. Three neurofibromas had associated neurofibromatosis type 1 (NF1). Eleven patients had one resection; others had CyberKnife after one (two) and two (three) operations. The malignant peripheral nerve sheath tumor (MPNST) had prior field-radiation and adds another case. Approaches included laminotomy and laminectomies with partial (three) or total (two) facetectomies/fusions. Two cases each had supraclavicular, lateral extracavitary, retroperitoneal and Wiltze and costotransversectomy/thoracotomy procedures. Two underwent a laminectomy/partial facetectomy, then CyberKnife. Pre-CyberKnife, one of two others had a laminectomy/partial facetectomy, then total facetectomy/fusion and the other, two supraclavicular approaches. The MPNST had a hemi-laminotomy then laminectomy/total facetectomy/fusion, followed by CyberKnife. Roots were preserved, except in two. Of 11 single-operation-peripheral nerve sheath tumors, the asymptomatic case remained stable, nine (92%) improved and one (9%) worsened. Examinations remained intact in three (27%) and improved in seven (64%). Two having a single operation then CyberKnife had improvement after both. Of two undergoing two operations, one had symptom resolution post-operatively, worsened 4 years post-CyberKnife then has remained unchanged after re-operation. The other such patient improved post-operatively, had no change after re-operation and improved post-CyberKnife. The MPNST had presentation improvement after the first operation, worsened and after the second surgery \\and CyberKnife, the patient expired from tumor spread. In conclusion, surgery is beneficial for pain relief and function preservation in foraminal nerve sheath tumors. Open surgery with CyberKnife

  18. Surgical strategies for managing foraminal nerve sheath tumors: the emerging role of CyberKnife ablation.

    PubMed

    Murovic, Judith A; Charles Cho, S; Park, Jon

    2010-02-01

    Sixteen Stanford University Medical Center (SUMC) patients with foraminal nerve sheath tumors had charts reviewed. CyberKnife radiosurgery was innovative in management. Parameters were evaluated for 16 foraminal nerve sheath tumors undergoing surgery, some with CyberKnife. Three neurofibromas had associated neurofibromatosis type 1 (NF1). Eleven patients had one resection; others had CyberKnife after one (two) and two (three) operations. The malignant peripheral nerve sheath tumor (MPNST) had prior field-radiation and adds another case. Approaches included laminotomy and laminectomies with partial (three) or total (two) facetectomies/fusions. Two cases each had supraclavicular, lateral extracavitary, retroperitoneal and Wiltze and costotransversectomy/thoracotomy procedures. Two underwent a laminectomy/partial facetectomy, then CyberKnife. Pre-CyberKnife, one of two others had a laminectomy/partial facetectomy, then total facetectomy/fusion and the other, two supraclavicular approaches. The MPNST had a hemi-laminotomy then laminectomy/total facetectomy/fusion, followed by CyberKnife. Roots were preserved, except in two. Of 11 single-operation-peripheral nerve sheath tumors, the asymptomatic case remained stable, nine (92%) improved and one (9%) worsened. Examinations remained intact in three (27%) and improved in seven (64%). Two having a single operation then CyberKnife had improvement after both. Of two undergoing two operations, one had symptom resolution post-operatively, worsened 4 years post-CyberKnife then has remained unchanged after re-operation. The other such patient improved post-operatively, had no change after re-operation and improved post-CyberKnife. The MPNST had presentation improvement after the first operation, worsened and after the second surgery \\and CyberKnife, the patient expired from tumor spread. In conclusion, surgery is beneficial for pain relief and function preservation in foraminal nerve sheath tumors. Open surgery with CyberKnife

  19. Treating Adrenal Tumors in 26 Patients with CyberKnife: A Mono-Institutional Experience

    PubMed Central

    Li, Jing; Shi, ZhaoRong; Wang, Zhen; Liu, Zhibing; Wu, Xinhu; Shen, Zetian; Li, Bing; Song, Yong; Zhu, Xixu

    2013-01-01

    Background CyberKnife (CK) is a novel stereotactic radiosurgery system for treating tumors in any part of the body. It is a non-invasive or minimally invasive tumor treatment modality that can deliver high doses of spatially precise radiation and minimize exposure to neighboring healthy tissues or vital organs. The purpose of this study was to investigate the safety and efficacy of CK in the treatment of adrenal tumors. Methods and Results We performed a retrospective analysis of 26 patients with adrenal tumors who had been treated with CK in the radiotherapy center of our hospital between March 2009 and March 2012. Eight patients had primary adrenal tumors and 18 patients had metastatic adrenal tumors. In addition to CK, 4 patients received chemotherapy and 2 patients received immunotherapy. The average tumor volume was 72.1 cm3 and the prescribed radiation dosage ranged from 30 to 50 Gy and was fractionated 3 to 5 times with a 58% to 80% isodose line. Abdominal CT was performed between 1 to 3 months after the CK treatment to evaluate the short-term efficacy with follow-up examinations once every 3 months. Three patients had complete remission, 12 patients had partial remission, 5 patients had stable disease, and 6 patients had progressive illness. The effective rate of pain relief was 93.8% and the disease control rate was 77% with a median overall survival of 17 months and a median progression-free survival of 14 months. Treatment Related toxicity was well-tolerated, but preventative measure need to be taken for radiation enteritis. Conclusions CK is safe and effective for treating adrenal tumors with few adverse reactions. Nonetheless, its long-term effects requires further follow-up. PMID:24278303

  20. [Application of robotized radiosurgical system CyberKnife for the treatment of neurosurgical patients].

    PubMed

    Konovalov, A N; Golanov, A V; Gorlachev, G E; Kornienko, V N; Trunin, Iu Iu; Kotel'nikova, T M; Zolotova, S V; Vetlova, E R; Galkin, M V; Antipina, N A; Mariashev, S A; Pronin, I N; Arutiunov, N V; Lubnin, A Iu; Iakovlev, S B

    2012-01-01

    Robotized system for radiosurgery CyberKnife (Accuray Inc., USA) is the first device dedicated and optimized for advanced irradiation during 1-7 fractions (i.e. radiosurgery and hypofractionation). CyberKnife is characterized by elaborate guidance system, high precision of dose delivery, possibility of conformal dose distributions with high gradient of target borderline dose which is most important in proximity of critical structures. The first CyberKnife system in Russia was installed in Burdenko Neurosurgery Institute. The paper presents 2-year experience of treating patients using CyberKnife. From April 2009 till October 2011 896 patients were treated using CyberKnife. Mean age was 48 years. Overall number of sessions was 2626. Radiosurgical procedures were performed in 21.8% of patients. 91% of cases were treated for intracranial lesions. Limited follow-up period in all kinds of pathology demonstrated results consistent with standard fractionation or radiosurgery. The rates of observed complications were also comparable with accepted techniques. CyberKnife system plays significant role in everyday activity of department of radiation therapy. In careful and thorough selection of patients it allows efficient and high-quality treatment of patients with neurosurgical diseases.

  1. Cyberknife treatment for advanced or terminal stage hepatocellular carcinoma

    PubMed Central

    Kato, Hiroyuki; Yoshida, Hideo; Taniguch, Hiroyoshi; Nomura, Ryutaro; Sato, Kengo; Suzuki, Ichiro; Nakata, Ryo

    2015-01-01

    AIM: To investigate the safety and efficacy of the Cyberknife treatment for patients with advanced or terminal stage hepatocellular carcinoma (HCC). METHODS: Patients with HCC with extrahepatic metastasis or vascular or bile duct invasion were enrolled between May 2011 and June 2015. The Cyberknife was used to treat each lesion. Treatment response scores were based on Response Evaluation Criteria in Solid Tumors v1.1. The trends of tumor markers, including alpha fetoprotein (AFP) and proteins induced by vitamin K absence II (PIVKA II) were assessed. Prognostic factors for tumor response and tumor markers were evaluated with Fisher’s exact test and a logistic regression model. Survival was evaluated with the Kaplan-Meier method and multivariate analysis was performed using the Cox proportional hazards model. RESULTS: Sixty-five patients with 95 lesions were enrolled. Based on the Barcelona Clinic Liver Cancer classification, all patients were either in the advanced or terminal stage of the disease. The target lesions were as follows: 52 were bone metastasis; 9, lung metastasis; 7, brain metastasis; 9, portal vein invasion; 4, hepatic vein invasion; 4, bile duct invasion; and 10 other lesion types. The response rate and disease control rate were 34% and 53%, respectively. None of the clinical factors correlated significantly with tumor response. Fiducial marker implantation was associated with better control of both AFP (HR = 0.152; 95%CI: 0.026-0.887; P = 0.036) and PIVKA II (HR = 0.035; 95%CI: 0.003-0.342; P = 0.004). The median survival time was 9 mo (95%CI: 5-15 mo). Terminal stage disease (HR = 9.809; 95%CI: 2.589-37.17, P < 0.001) and an AFP of more than 400 ng/mL (HR = 2.548; 95%CI: 1.070-6.068, P = 0.035) were associated with worse survival. A radiation dose higher than 30 Gy (HR = 0.274; 95%CI: 0.093-0.7541, P = 0.012) was associated with better survival. In the 52 cases of bone metastasis, 36 patients (69%) achieved pain relief. One patient had cerebral

  2. Intrafractional Motion of the Prostate During Hypofractionated Radiotherapy

    SciTech Connect

    Xie Yaoqin; Djajaputra, David; King, Christopher R.; Hossain, Sabbir; Ma Lijun; Xing Lei

    2008-09-01

    Purpose: To report the characteristics of prostate motion as tracked by the stereoscopic X-ray images of the implanted fiducials during hypofractionated radiotherapy with CyberKnife. Methods and Materials: Twenty-one patients with prostate cancer who were treated with CyberKnife between January 2005 and September 2007 were selected for this retrospective study. The CyberKnife uses a stereoscopic X-ray system to obtain the position of the prostate target through the monitoring of implanted gold fiducial markers. If there is a significant deviation, the treatment is paused while the patient is repositioned by moving the couch. The deviations calculated from X-ray images acquired within the time interval between two consecutive couch motions constitute a data set. Results: Included in the analysis were 427 data sets and 4,439 time stamps of X-ray images. The mean duration for each data set was 697 sec. At 30 sec, a motion >2 mm exists in about 5% of data sets. The percentage is increased to 8%, 11%, and 14% at 60 sec, 90 sec, and 120 sec, respectively. A similar trend exists for other values of prostate motion. Conclusions: With proper monitoring and intervention during treatment, the prostate shifts observed among patients can be kept within the tracking range of the CyberKnife. On average, a sampling rate of {approx}40 sec between consecutive X-rays is acceptable to ensure submillimeter tracking. However, there is significant movement variation among patients, and a higher sampling rate may be necessary in some patients.

  3. Image-guided robotic radiosurgery (CyberKnife) for pancreatic insulinoma: is laparoscopy becoming old?

    PubMed

    Huscher, Cristiano Germano Sigismondo; Mingoli, Andrea; Sgarzini, Giovanna; Mereu, Andrea; Gasperi, Maurizio

    2012-03-01

    Insulinomas constitute about 25% of endocrine pancreatic tumors. Laparoscopic surgery is the treatment of choice. However, pancreas-related complications rate is very high, even in experienced hands, ranging up to 37%. Alternative procedures such as embolization with trisacryl have not been accepted by the surgical community. Image-guided robotic radiosurgery or stereotactic radiosurgery (CyberKnife) is a minimally invasive procedure delivering large doses of ionizing radiation to a well-defined target. CyberKnife radiosurgery is successfully used in brain cancer, lung cancer, prostate cancer, liver metastases, kidney cancer, and pancreatic cancer. The authors present the first case to their knowledge of a benign functioning insulinoma successfully treated by a CyberKnife technique with a 3-year follow-up.

  4. Successful Treatment of Eccrine Porocarcinoma Metastasized to a Cervical Lymph Node with CyberKnife Radiosurgery.

    PubMed

    Fujimura, Taku; Hashimoto, Akira; Furudate, Sadanori; Kambayashi, Yumi; Haga, Takahiro; Aiba, Setsuya

    2014-05-01

    Eccrine porocarcinoma is a rare type of skin cancer that originates from eccrine sweat glands or acrosyringium and mainly occurs in the elderly. In this report, we describe an 85-year-old Japanese woman with eccrine porocarcinoma that metastasized to a cervical lymph node who was cured with CyberKnife radiosurgery. Because our patient had a high risk of perioperative complication, standard surgical therapy with a wide margin was impractical. Our present study suggests the novel possibility of using CyberKnife for the treatment of inoperable metastatic porocarcinoma.

  5. [Recent developments in radiotherapy of hepatocellular carcinoma].

    PubMed

    Seong, Jinsil

    2004-12-01

    With the accumulation of clinical experiences, the efficacy of radiotherapy has been recognized in management scheme for HCC. While hepatologists are beginning to show less reluctance for applying radiotherapy to the treatment of HCC, it is necessary that the hepatologists be informed of the rapid developments in technical strategy for radiation oncology. Recent advances in several technologies have opened a new era in radiation oncology. Modern imaging technologies can provide a 3-dimensional model of patient's anatomy, and this allows radiation oncologists to identify accurate tumor volumes as well as the tumors' relationship with the adjacent normal tissues. Moreover, the development of the computer-controlled multileaf collimator systems now enables physicians to perform precise beam shaping and to modulate the radiation dose distribution. A combination of these systems, 3-DCRT, is rapidly replacing the more conventional 2-D radiotherapy. 3-DCRT has evolved into a more sophisticated technology, intensity modulated radiotherapy (IMRT). In IMRT, with the powerful computer-aided optimization process, the radiation dose can be delivered to the target using highly complex isodose profiles. This new technology has been further developed into IGRT, which combines the CT-images scanning system and radiation equipments into one hardware package, and this system is currently ready for clinical application. In parallel with the radiation technologies described above, the strategy of stereotactic radiation has evolved from the conventional linear accelerator-based system to a gammaknife, and more recently, to a cyberknife. These systems are primarily based on the concept of radiosurgery. Currently, various radiation technologies have been adopted for the radiotherapy of HCC. In this article, each strategy will be discussed as well as the indications for radiotherapy and the radiation-related complications.

  6. 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.

  7. Peripheral dose measurement for CyberKnife radiosurgery with upgraded linac shielding

    SciTech Connect

    Chuang, Cynthia F.; Larson, David A.; Zytkovicz, Andrea; Smith, Vernon; Petti, Paula L.

    2008-04-15

    The authors investigated the peripheral dose reduction for CyberKnife radiosurgery treatments after the installation of a linac shielding upgrade. As in a previous investigation, the authors considered two treatment plans, one for a hypothetical target in the brain and another for a target in the thorax, delivered to an anthropomorphic phantom. The results of the prior investigation showed that the CyberKnife delivered significantly higher peripheral doses than comparable model C Gamma Knife or IMRT treatments. Current measurements, after the linac shielding upgrade, demonstrate that the additional shielding decreased the peripheral dose, expressed as a percentage of the delivered monitor units (MU), by a maximum of 59%. The dose reduction was greatest for cranial-caudal distances from the field edge less than 30 cm, and at these distances, the CyberKnife peripheral dose, expressed as a percentage of the delivered MU, is now comparable to that measured for the other treatment modalities in our previous investigation. For distances between 30 and 70 cm from the field edge, the additional shielding reduced the peripheral dose by between 20% and 55%. At these distances, the CyberKnife peripheral dose remains higher than doses measured in our previous study for the model C Gamma Knife and IMRT.

  8. CT-Guided Fiducial Placement for CyberKnife Stereotactic Radiosurgery: An Initial Experience

    SciTech Connect

    Sotiropoulou, Evangelia; Stathochristopoulou, Irene; Stathopoulos, Konstantinos; Verigos, Kosmas; Salvaras, Nikolaos; Thanos, Loukas

    2010-06-15

    CyberKnife frameless image-guided radiosurgery has become a widely used system for parenchymal extracranial lesions. Gold fiducials are required for the planning and aiming of CyberKnife therapy. We report our initial experience and describe the technique of positioning tumor markers, under CT guidance. We conducted a retrospective review of 105 patients who were referred for CyberKnife stereotactic radiosurgery at Iatropolis CyberKnife Center in Athens. All patients underwent percutaneous fiducial placement via CT guidance. At the desired location, the 18-G needle was advanced into or near the tumor. Data collected included number and locations of fiducials placed and complications experienced to date. One hundred five patients underwent fiducial placement under CT guidance and a total number of 319 gold seeds were implanted. We experienced one episode of pneumothorax that required drainage, one mild pneumothorax, and three episodes of perifocal pulmonary hemorrhage. In conclusion, fiducial implantation under CT guidance appears to be a safe and efficient procedure, as long as it is performed by an experienced interventional radiologist.

  9. Extracranial Facial Nerve Schwannoma Treated by Hypo-fractionated CyberKnife Radiosurgery

    PubMed Central

    Miyazaki, Shinichiro; Hori, Tomokatsu

    2016-01-01

    Facial nerve schwannoma is a rare intracranial tumor. Treatment for this benign tumor has been controversial. Here, we report a case of extracranial facial nerve schwannoma treated successfully by hypo-fractionated CyberKnife (Accuray, Sunnyvale, CA) radiosurgery and discuss the efficacy of this treatment. A 34-year-old female noticed a swelling in her right mastoid process. The lesion enlarged over a seven-month period, and she experienced facial spasm on the right side. She was diagnosed with a facial schwannoma via a magnetic resonance imaging (MRI) scan of the head and neck and was told to wait until the facial nerve palsy subsides. She was referred to our hospital for radiation therapy. We planned a fractionated CyberKnife radiosurgery for three consecutive days. After CyberKnife radiosurgery, the mass in the right parotid gradually decreased in size, and the facial nerve palsy disappeared. At her eight-month follow-up, her facial spasm had completely disappeared. There has been no recurrence and the facial nerve function has been normal. We successfully demonstrated the efficacy of CyberKnife radiosurgery as an alternative treatment that also preserves neurofunction for facial nerve schwannomas. PMID:27774363

  10. Extracranial Facial Nerve Schwannoma Treated by Hypo-fractionated CyberKnife Radiosurgery.

    PubMed

    Sasaki, Ayaka; Miyazaki, Shinichiro; Hori, Tomokatsu

    2016-09-21

    Facial nerve schwannoma is a rare intracranial tumor. Treatment for this benign tumor has been controversial. Here, we report a case of extracranial facial nerve schwannoma treated successfully by hypo-fractionated CyberKnife (Accuray, Sunnyvale, CA) radiosurgery and discuss the efficacy of this treatment. A 34-year-old female noticed a swelling in her right mastoid process. The lesion enlarged over a seven-month period, and she experienced facial spasm on the right side. She was diagnosed with a facial schwannoma via a magnetic resonance imaging (MRI) scan of the head and neck and was told to wait until the facial nerve palsy subsides. She was referred to our hospital for radiation therapy. We planned a fractionated CyberKnife radiosurgery for three consecutive days. After CyberKnife radiosurgery, the mass in the right parotid gradually decreased in size, and the facial nerve palsy disappeared. At her eight-month follow-up, her facial spasm had completely disappeared. There has been no recurrence and the facial nerve function has been normal. We successfully demonstrated the efficacy of CyberKnife radiosurgery as an alternative treatment that also preserves neurofunction for facial nerve schwannomas.

  11. 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

  12. SU-E-T-305: Dosimetric Comparison of Cyberknife Versus Linac Based VMAT Stereotactic Treatment Planning for Localised Prostate Cancer

    SciTech Connect

    Senniandavar, V; Vikraman, S; KP, K; Rajesh, T; Sambasivaselli, R; Ramu, M; Maragathaveni, S; Dhivya, N; Tejinder, K

    2015-06-15

    Purpose: The purpose of this study was to compare dosimetric indices of Cyberknife versus Linac for localised prostate cancer Methods: In this study, twenty patients were taken from Cyberknife Multiplan TPS v 4.6.0. All these patients underwent hypo fractionated boost treatment for localised prostate cancer in Cyberknife with the prescription dose of 18Gy in 3 fractions. For each patient VMAT stereotactic plans were generated in Monaco TPS v 5.0 using Elekta beam modulator MLC machine for 6MV photon beam. The plans quality were evaluated by comparing dosimetry indices such that D95, D90, D5 for target volume and V100, V80, V50, V30 for critical organs. The p values were calculated for target and OAR to ascertain the significant differences. Results: For each case, D95 of target coverage was achieved with 100% prescription dose with p value of 0.9998. The p value for D90, D5 and V100 for linac and Cyberknife plans was 0.9938, 0.9918 and 0.9838 respectively. For rectum, rectum-PTV and bladder doses were significantly less in Cyberknife compared to linac plans. For rectum, rectum-PTV and bladder at V100 the p value is 0.2402, 0.002, and 0.1615 respectively. Other indices V80, V50 and V30 were comparable in both plans. Conclusion: This study demonstrated that both linac and Cyberknife plans were shown adequate target coverage, while in Cyberknife the treatment time is longer and more MUs to be delivered. However, better conformity, lesser doses to the critical organs and dose gradient outside target for localised prostate treatment were achieved in Cyberknife plans due to multiple non coplanar beam arrangements.

  13. Virtual HDR CyberKnife treatment for localized prostatic carcinoma: dosimetry comparison with HDR brachytherapy and preliminary clinical observations.

    PubMed

    Fuller, Donald B; Naitoh, John; Lee, Charles; Hardy, Steven; Jin, Haoran

    2008-04-01

    We tested our ability to approximate the dose (38 Gy), fractionation (four fractions), and distribution of high-dose-rate (HDR) brachytherapy for prostate cancer with CyberKnife (CK) stereotactic body radiotherapy (SBRT) plans. We also report early clinical observations of CK SBRT treatment. Ten patients were treated with CK. For each CK SBRT plan, an HDR plan was designed using common contour sets and simulated HDR catheters. Planning target volume coverage, intraprostatic dose escalation, and urethra, rectum, and bladder exposure were compared. Planning target volume coverage by the prescription dose was similar for CK SBRT and HDR plans, whereas percent of volume of interest receiving 125% of prescribed radiation dose (V125) and V150 values were higher for HDR, reflecting higher doses near HDR source dwell positions. Urethra dose comparisons were lower for CK SBRT in 9 of 10 cases, suggesting that CK SBRT may more effectively limit urethra dose. Bladder maximum point doses were higher with HDR, but bladder dose falloff beyond the maximum dose region was more rapid with HDR. Maximum rectal wall doses were similar, but CK SBRT created sharper rectal dose falloff beyond the maximum dose region. Second CK SBRT plans, constructed by equating urethra radiation dose received by point of maximum exposure of volume of interest to the HDR plan, significantly increased V125 and V150. Clinically, 4-month post-CK SBRT median prostate-specific antigen levels decreased 86% from baseline. Acute toxicity was primarily urologic and returned to baseline by 2 months. Acute rectal morbidity was minimal and transient. It is possible to construct CK SBRT plans that closely recapitulate HDR dosimetry and deliver the plans noninvasively.

  14. Reference dosimetry condition and beam quality correction factor for CyberKnife beam

    SciTech Connect

    Kawachi, Toru; Saitoh, Hidetoshi; Inoue, Mitsuhiro; Katayose, Tetsurou; Myojoyama, Atsushi; Hatano, Kazuo

    2008-10-15

    This article is intended to improve the certainty of the absorbed dose determination for reference dosimetry in CyberKnife beams. The CyberKnife beams do not satisfy some conditions of the standard reference dosimetry protocols because of its unique treatment head structure and beam collimating system. Under the present state of affairs, the reference dosimetry has not been performed under uniform conditions and the beam quality correction factor k{sub Q} for an ordinary 6 MV linear accelerator has been temporally substituted for the k{sub Q} of the CyberKnife in many sites. Therefore, the reference conditions and k{sub Q} as a function of the beam quality index in a new way are required. The dose flatness and the error of dosimeter reading caused by radiation fields and detector size were analyzed to determine the reference conditions. Owing to the absence of beam flattening filter, the dose flatness of the CyberKnife beam was inferior to that of an ordinary 6 MV linear accelerator. And if the absorbed dose is measured with an ionization chamber which has cavity length of 2.4, 1.0 and 0.7 cm in reference dosimetry, the dose at the beam axis for a field of 6.0 cm collimator was underestimated 1.5%, 0.4%, and 0.2% on a calculation. Therefore, the maximum field shaped with a 6.0 cm collimator and ionization chamber which has a cavity length of 1.0 cm or shorter were recommended as the conditions of reference dosimetry. Furthermore, to determine the k{sub Q} for the CyberKnife, the realistic energy spectrum of photons and electrons in water was simulated with the BEAMnrc. The absence of beam flattening filter also caused softer photon energy spectrum than that of an ordinary 6 MV linear accelerator. Consequently, the k{sub Q} for ionization chambers of a suitable size were determined and tabulated as a function of measurable beam quality indexes in the CyberKnife beam.

  15. CyberArc: a non-coplanar-arc optimization algorithm for CyberKnife

    NASA Astrophysics Data System (ADS)

    Kearney, Vasant; Cheung, Joey P.; McGuinness, Christopher; Solberg, Timothy D.

    2017-07-01

    The goal of this study is to demonstrate the feasibility of a novel non-coplanar-arc optimization algorithm (CyberArc). This method aims to reduce the delivery time of conventional CyberKnife treatments by allowing for continuous beam delivery. CyberArc uses a 4 step optimization strategy, in which nodes, beams, and collimator sizes are determined, source trajectories are calculated, intermediate radiation models are generated, and final monitor units are calculated, for the continuous radiation source model. The dosimetric results as well as the time reduction factors for CyberArc are presented for 7 prostate and 2 brain cases. The dosimetric quality of the CyberArc plans are evaluated using conformity index, heterogeneity index, local confined normalized-mutual-information, and various clinically relevant dosimetric parameters. The results indicate that the CyberArc algorithm dramatically reduces the treatment time of CyberKnife plans while simultaneously preserving the dosimetric quality of the original plans.

  16. 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

  17. Clinical efficacy of CyberKnife combined with chemotherapy and hyperthermia for advanced non-small cell lung cancer.

    PubMed

    Wang, Yuan-Yuan; Lin, Si-Xiang; Yang, Gui-Qing; Liu, Han-Chen; Sun, Dong-Ning; Wang, Yi-Shan

    2013-05-01

    Non-small cell lung cancer (NSCLC) is responsible for at least 80% of all lung tumors and has a poor prognosis, since 75% of NSCLCs are first diagnosed at an advanced stage. This study was conducted to evaluate the therapeutic efficacy of CyberKnife in combination with chemotherapy and hyperthermia for selected patients with advanced non-small cell lung cancer (NSCLC). Clinical charts, imaging and pathology reports of patients with advanced NSCLC who underwent CyberKnife therapy in our Tumor Therapy Center were retrospectively reviewed. Clinical efficacy was evaluated for local control, Karnofsky performance status scale (KPS) and toxicity analysis. A total of 119 patients with 136 target areas were evaluated. A prescribed dose of 24-51 Gy to the gross tumor volume was delivered in 3-6 fractions. The median prescription dose was 35 Gy (mean, 34.73±4.80 Gy), with an average of five fractions. Patients, who voluntarily participated in the study, were assigned to one of three groups, which were as follows: CyberKnife therapy alone, CyberKnife combined with chemotherapy and CyberKnife combined with chemotherapy and hyperthermia. The median follow-up period was 6 months and curative efficiencies were 62.16, 71.79 and 90.70%, respectively, as determined by radiographic and clinical re-examinations. Patients treated by CyberKnife combined with chemotherapy and hyperthermia achieved optimal improvement in the aspect of KPS, which was statistically different compared to the other two groups (P<0.05). In conclusion, our results indicated that CyberKnife combined with chemotherapy and hyperthermia achieved favorable short-term outcomes and may be a more viable option for patients with advanced NSCLC. However, further investigations are required to evaluate long-term outcomes.

  18. SU-E-T-397: Evaluation of Planned Dose Distributions by Monte Carlo (0.5%) and Ray Tracing Algorithm for the Spinal Tumors with CyberKnife

    SciTech Connect

    Cho, H; Brindle, J; Hepel, J

    2015-06-15

    Purpose: To analyze and evaluate dose distribution between Ray Tracing (RT) and Monte Carlo (MC) algorithms of 0.5% uncertainty on a critical structure of spinal cord and gross target volume and planning target volume. Methods: Twenty four spinal tumor patients were treated with stereotactic body radiotherapy (SBRT) by CyberKnife in 2013 and 2014. The MC algorithm with 0.5% of uncertainty is used to recalculate the dose distribution for the treatment plan of the patients using the same beams, beam directions, and monitor units (MUs). Results: The prescription doses are uniformly larger for MC plans than RT except one case. Up to a factor of 1.19 for 0.25cc threshold volume and 1.14 for 1.2cc threshold volume of dose differences are observed for the spinal cord. Conclusion: The MC recalculated dose distributions are larger than the original MC calculations for the spinal tumor cases. Based on the accuracy of the MC calculations, more radiation dose might be delivered to the tumor targets and spinal cords with the increase prescription dose.

  19. A retrospective analysis of tumor volumetric responses to five-fraction stereotactic radiotherapy for paragangliomas of the head and neck (glomus tumors).

    PubMed

    Chun, Stephen G; Nedzi, Lucien A; Choe, Kevin S; Abdulrahman, Ramzi E; Chen, Susie A; Yordy, John S; Timmerman, Robert D; Kutz, Joe W; Isaacson, Brandon

    2014-01-01

    Skull base paragangliomas (SBP) are locally expansile tumors that can be treated with stereotactic radiotherapy with favorable results. This report describes the results of 31 patients with SBP treated with CyberKnife radiotherapy delivering a total dose of 25 Gray in five fractions. All patients treated with five-fraction CyberKnife radiotherapy at a single institution were identified between 2007 and 2013. Tumor volumetric analyses were performed to assess responses to radiotherapy. Median follow-up was 24 months with a range of 4-78 months. Local control and overall survival were 100%. Of the 20 patients who presented with tinnitus, 12 reported improvement (60%), of whom 6 reported complete resolution. There was a 37.3% reduction in tumor volume among all patients (p = 0.16). On subset analysis of patients with ≥24 months of follow-up, tumor volume decreased 49% (p = 0.01). The rate of grade 1-2 toxicity was 19%, with no grade 3 or worse toxicity. A five-fraction CyberKnife-based stereotactic radiotherapy approach is safe and efficacious for the management for patients with SBP. Our findings suggest the potential use of this strategy as a definitive or salvage treatment option for SBP.

  20. Dosimetry analyses comparing high-dose-rate brachytherapy, administered as monotherapy for localized prostate cancer, with stereotactic body radiation therapy simulated using CyberKnife

    PubMed Central

    Fukuda, Shoichi; Seo, Yuji; Shiomi, Hiroya; Yamada, Yuji; Ogata, Toshiyuki; Morimoto, Masahiro; Konishi, Koji; Yoshioka, Yasuo; Ogawa, Kazuhiko

    2014-01-01

    The purpose of this study was to perform dosimetry analyses comparing high-dose-rate brachytherapy (HDR-BT) with simulated stereotactic body radiotherapy (SBRT). We selected six consecutive patients treated with HDR-BT monotherapy in 2010, and a CyberKnife SBRT plan was simulated for each patient using computed tomography images and the contouring set used in the HDR-BT plan for the actual treatment, but adding appropriate planning target volume (PTV) margins for SBRT. Then, dosimetric profiles for PTVs of the rectum, bladder and urethra were compared between the two modalities. The SBRT plan was more homogenous and provided lower dose concentration but better coverage for the PTV. The maximum doses in the rectum were higher in the HDR-BT plans. However, the HDR-BT plan provided a sharper dose fall-off around the PTV, resulting in a significant and considerable difference in volume sparing of the rectum with the appropriate PTV margins added for SBRT. While the rectum D5cm3 for HDR-BT and SBRT was 30.7 and 38.3 Gy (P < 0.01) and V40 was 16.3 and 20.8 cm3 (P < 0.01), respectively, SBRT was significantly superior in almost all dosimetric profiles for the bladder and urethra. These results suggest that SBRT as an alternative to HDR-BT in hypofractionated radiotherapy for prostate cancer might have an advantage for bladder and urethra dose sparing, but for the rectum only when proper PTV margins for SBRT are adopted. PMID:24957754

  1. Dosimetry analyses comparing high-dose-rate brachytherapy, administered as monotherapy for localized prostate cancer, with stereotactic body radiation therapy simulated using CyberKnife.

    PubMed

    Fukuda, Shoichi; Seo, Yuji; Shiomi, Hiroya; Yamada, Yuji; Ogata, Toshiyuki; Morimoto, Masahiro; Konishi, Koji; Yoshioka, Yasuo; Ogawa, Kazuhiko

    2014-11-01

    The purpose of this study was to perform dosimetry analyses comparing high-dose-rate brachytherapy (HDR-BT) with simulated stereotactic body radiotherapy (SBRT). We selected six consecutive patients treated with HDR-BT monotherapy in 2010, and a CyberKnife SBRT plan was simulated for each patient using computed tomography images and the contouring set used in the HDR-BT plan for the actual treatment, but adding appropriate planning target volume (PTV) margins for SBRT. Then, dosimetric profiles for PTVs of the rectum, bladder and urethra were compared between the two modalities. The SBRT plan was more homogenous and provided lower dose concentration but better coverage for the PTV. The maximum doses in the rectum were higher in the HDR-BT plans. However, the HDR-BT plan provided a sharper dose fall-off around the PTV, resulting in a significant and considerable difference in volume sparing of the rectum with the appropriate PTV margins added for SBRT. While the rectum D5cm(3) for HDR-BT and SBRT was 30.7 and 38.3 Gy (P < 0.01) and V40 was 16.3 and 20.8 cm(3) (P < 0.01), respectively, SBRT was significantly superior in almost all dosimetric profiles for the bladder and urethra. These results suggest that SBRT as an alternative to HDR-BT in hypofractionated radiotherapy for prostate cancer might have an advantage for bladder and urethra dose sparing, but for the rectum only when proper PTV margins for SBRT are adopted.

  2. [A Case of Local Recurrence and Lung Metastasis from a Rectal Cancer Treated with Systemic Chemotherapy and Cyberknife].

    PubMed

    Uchino, Tairin; Mishima, Hideyuki; Osawa, Takaaki; Matsumura, Tatsuki; Komaya, Kenichi; Kimura, Kengo; Ando, Keiichi; Saito, Takuya; Ishiguro, Seiji; Ohashi, Norifumi; Arikawa, Takashi; Komatsu, Shunichiro; Miyachi, Masahiko; Mizumatsu, Shinichiro; Sano, Tsuyoshi

    2015-11-01

    A 73-year-old man underwent abdominoperineal resection for a rectal cancer. He developed a hip pain 3 years and 6 months after the surgery. A CT scan revealed a local recurrence in the perineum and multiple lung metastases in the bilateral lung. He received systemic chemotherapy consisting of XELOX with bevacizumab. Thereafter, the hip pain was slightly relieved. The hip pain worsened 1 year and 6 months after the recurrence. The border between the perineal tumor and skin was very narrow, and conventional radiation therapy could cause a perineal skin necrosis and subsequent poor wound healing. Therefore, we selected a Cyberknife treatment. The hip pain was relieved and a CT scan showed a reduction of the perineal tumor's size after the Cyberknife treatment. A Cyberknife treatment may be effective and promising as palliation for patients with local recurrence of rectal cancer.

  3. A dosimetric comparison between CyberKnife and tomotherapy treatment plans for single brain metastasis.

    PubMed

    Greto, Daniela; Pallotta, Stefania; Masi, Laura; Talamonti, Cinzia; Marrazzo, Livia; Doro, Raffaella; Saieva, Calogero; Scoccianti, Silvia; Desideri, Isacco; Livi, Lorenzo

    2017-05-01

    Radiosurgery (RS) is a well-established treatment in selected patients with brain metastasis. The aim of this study is to compare the differences between CyberKnife (CK) and TomoTherapy (HT) treatment plans of RS of single brain metastasis (BM) to define when HT should be used in cases beyond Cyberknife-when both systems are readily available for the radiation oncologist. Nineteen patients with single brain metastasis treated with CK were re-planned for radiosurgery using TomoTherapy Hi-ART system. Two planning approaches have been used for TomoTherapy plans: the classical one (HT) and the improved conformity (icHT) that produces dose distributions more similar to those of RS plans. PTV coverage, Conformity Index (CI), Paddick Conformity Index (nCI), Homogeneity Index (HI), Gradient Index (GI), and beam on time of CK, HT, and icHT plans were evaluated and compared. A good coverage was found for CK, HT, and icHT plans. A difference between mean HI of CK and icHT plans was observed (p = 0.007). Better dose gradients compared to both icHT and HT modalities were observed in CK plans. icHT modality showed improved mean CI respect to HT modality, similar to that obtained in CK plans. CK plans show higher conformity and lower GI than icHT and HT plans. TomoTherapy demonstrates the advantage of being a device capable to reach different clinical objectives depending on the different planning modality employed. CyberKnife and TomoTherapy are both optimal RS devices, the choice to use one over another has to be clinically guided.

  4. Implementation of Fiducial-Based Image Registration in the Cyberknife Robotic System

    SciTech Connect

    Saw, Cheng B. Chen Hungcheng; Wagner, Henry

    2008-07-01

    Fiducial-based image registration methodology as implemented in the Cyberknife system is explored. The Cyberknife is a radiosurgery system that uses image guidance technology and computer-controlled robotics to determine target positions and adjust beam directions accordingly during the dose delivery. The image guidance system consists of 2 x-ray sources mounted on the ceiling and a detection system mounted on both sides of the treatment couch. Two orthogonal live radiographs are taken prior to and during patient treatment. Fiducial markers are identified on these radiographs and compared to a library of digital reconstructed radiographs (DRRs) using the fiducial extraction software. The fiducial extraction software initially sets an intensity threshold on the live radiographs to generate white areas on black images referred to as 'blobs.' Different threshold values are being used and blobs at the same location are assumed to originate from the same object. The number of blobs is then reduced by examining each blob against a predefined set of properties such as shape and exposure levels. The remaining blobs are further reduced by examining the location of the blobs in the inferior-superior patient axis. Those blobs that have the corresponding positions are assumed to originate from the same object. The remaining blobs are used to create fiducial configurations and are compared to the reference configuration from the computed tomography (CT) image dataset for treatment planning. The best-fit configuration is considered to have the appropriate fiducial markers. The patient position is determined based on these fiducial markers. During the treatment, the radiation beam is turned off when the Cyberknife changes nodes. This allows a time window to acquire live radiographs for the determination of the patient target position and to update the robotic manipulator to change beam orientations accordingly.

  5. Dosimetric analysis of trigeminal nerve, brain stem doses in CyberKnife radiosurgery of trigeminal neuralgia.

    PubMed

    Sudahar, H; Kurup, P G G; Murali, V; Velmurugan, J

    2012-07-01

    CyberKnife radiosurgery treatment of Trigeminal neuralgia (TN) is performed as a non-invasive image guided procedure. The prescription dose for TN is very high. The brainstem is the adjacent critical organ at risk (OAR) which is prone to receive the very high target dose of TN. The present study is to analyze the dose distribution inside the tiny trigeminal nerve target and also to analyze the dose fall off in the brain stem. Seven TN cases treated between November 2010 and January 2012 were taken for this study retrospectively. The treatment plans were analyzed for target dose conformity, homogeneity and dose coverage. In the brainstem the volume doses D(1%), D(2%) were taken for analyzing the higher doses in the brain stem. The dose fall off was analyzed in terms of D(5%) and D(10%). The mean value of maximum dose within the trigeminal nerve target was 73.5±2.1Gy (P=0.0007) and the minimum dose was 50.0±4.1Gy (P=0.1315). The mean conformity index was 2.19 and the probable reason could be the smallest CyberKnife collimator of 5mm used in the treatment plan. The mean D(1%), of the brainstem was 10.5± 2.1Gy (P=0.5316) and the mean value of the maximum point dose within the brainstem was 35.6±3.8Gy. This shows the degree of dose fall off within the brainstem. Though the results of the present study are showing superior sparing of brain stem and reasonable of target coverage, it is necessary to execute the treatment plan with greater accuracy in CyberKnife as the immobilization is noninvasive and frameless.

  6. CyberKnife beam output factor measurements: A multi-site and multi-detector study.

    PubMed

    Masi, Laura; Russo, Serenella; Francescon, Paolo; Doro, Raffaela; Frassanito, Maria Cristina; Fumagalli, Maria Luisa; Reggiori, Giacomo; Marinelli, Marco; Redaelli, Irene; Pimpinella, Maria; Verona Rinati, Gianluca; Siragusa, Carmelo; Vigorito, Sabrina; Mancosu, Pietro

    2016-12-01

    New promising detectors are available for measuring small field size output factors (OFs). This study focused on a multicenter evaluation of two new generation detectors for OF measurements on CyberKnife systems. PTW-60019 microDiamond and W1 plastic scintillation detector (PSD) were used to measure OFs on eight CyberKnife units of various generations for 5-60mm fixed cones. MicroDiamond and PSD OF were compared to routinely used silicon diodes data corrected applying published Monte Carlo (MC) factors. PSD data were corrected for Čerenkov Light Ratio (CLR). The uncertainties related to CLR determination were estimated. Considering OF values averaged over all centers, the differences between MC corrected diode and the other two detectors were within 1.5%. MicroDiamond exhibited an over-response of 1.3% at 7.5mm and a trend inversion at 5mm with a difference of 0.2%. This behavior was consistent among the different units. OFs measured by PSD slightly under-responded compared to MC corrected diode for the smaller cones and the differences were within 1%. The observed CLR variability was 2.5% and the related variation in OF values was 1.9%. This study indicates that CyberKnife microDiamond OF require corrections below 2%. The results are enhanced by the consistency observed among different units. Scintillator shows a good agreement to MC corrected diode but CLR determination remains critical requiring further investigations. The results emphasized the value of a multi-center validation over a single center approach. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  7. Patterns of care of radiotherapy in México

    PubMed Central

    Poitevin-Chacón, Adela; Hinojosa-Gómez, José

    2012-01-01

    Aim This survey is performed to learn about the structure of radiotherapy in México. Background Radiation oncology practice is increasing because of the higher incidence of cancer. There is no published data about radiotherapy in México. Materials and methods A questionnaire was sent to the 83 registered centers in the database of the Mexican regulatory agency. One out of the 32 states has no radiotherapy. 27 centers from 14 states provided their answers. Results 829 patients are treated annually with any radiotherapy modality in each center. Two centers have one cobalt machine, 7 have a cobalt and a linac and 10 have more than one linac. Five centers use 2D planning systems, 22 use 3D; 9, conventional simulators; 22, CT based simulation, and 1 center has no simulation. Most of the centers verify beams with films, electronic portal image devices and cone beam CTs are also used. Intensity modulated and image guided radiotherapy are performed in 5 states. Breast, prostate, cervix, lung, rectum and head and neck cancer are the six most common locations. There are 45 public and 38 private centers, 2 dedicated to children. Two gamma knife units, 5 Novalis systems, 1 tomotherapy and 2 cyberknife machines are working. All centers have at least one radiation oncologist, one physicist and one radiotherapist. Conclusions Definitive conclusions cannot be drawn from this limited feedback due to a low participation of centers. This survey about radiotherapy in Mexico shows the heterogeneity of equipment as well as medical and technical staff in the whole country. PMID:24416531

  8. Integral dose: Comparison between four techniques for prostate radiotherapy.

    PubMed

    Ślosarek, Krzysztof; Osewski, Wojciech; Grządziel, Aleksandra; Radwan, Michał; Dolla, Łukasz; Szlag, Marta; Stąpór-Fudzińska, Małgorzata

    2015-01-01

    Comparisons of integral dose delivered to the treatment planning volume and to the whole patient body during stereotactic, helical and intensity modulated radiotherapy of prostate. Multifield techniques produce large volumes of low dose inside the patient body. Delivered dose could be the result of the cytotoxic injuries of the cells even away from the treatment field. We calculated the total dose absorbed in the patient body for four radiotherapy techniques to investigate whether some methods have a potential to reduce the exposure to the patient. We analyzed CyberKnife plans for 10 patients with localized prostate cancer. Five alternative plans for each patient were calculated with the VMAT, IMRT and TomoTherapy techniques. Alternative dose distributions were calculated to achieve the same coverage for PTV. Integral Dose formula was used to calculate the total dose delivered to the PTV and whole patient body. Analysis showed that the same amount of dose was deposited to the treated volume despite different methods of treatment delivery. The mean values of total dose delivered to the whole patient body differed significantly for each treatment technique. The highest integral dose in the patient's body was at the TomoTherapy and CyberKnife treatment session. VMAT was characterized by the lowest integral dose deposited in the patient body. The highest total dose absorbed in normal tissue was observed with the use of a robotic radiosurgery system and TomoTherapy. These results demonstrate that the exposure of healthy tissue is a dosimetric factor which differentiates the dose delivery methods.

  9. A pencil beam dose calculation model for CyberKnife system.

    PubMed

    Liang, Bin; Li, Yongbao; Liu, Bo; Zhou, Fugen; Xu, Shouping; Wu, Qiuwen

    2016-10-01

    CyberKnife system is initially equipped with fixed circular cones for stereotactic radiosurgery. Two dose calculation algorithms, Ray-Tracing and Monte Carlo, are available in the supplied treatment planning system. A multileaf collimator system was recently introduced in the latest generation of system, capable of arbitrarily shaped treatment field. The purpose of this study is to develop a model based dose calculation algorithm to better handle the lateral scatter in an irregularly shaped small field for the CyberKnife system. A pencil beam dose calculation algorithm widely used in linac based treatment planning system was modified. The kernel parameters and intensity profile were systematically determined by fitting to the commissioning data. The model was tuned using only a subset of measured data (4 out of 12 cones) and applied to all fixed circular cones for evaluation. The root mean square (RMS) of the difference between the measured and calculated tissue-phantom-ratios (TPRs) and off-center-ratio (OCR) was compared. Three cone size correction techniques were developed to better fit the OCRs at the penumbra region, which are further evaluated by the output factors (OFs). The pencil beam model was further validated against measurement data on the variable dodecagon-shaped Iris collimators and a half-beam blocked field. Comparison with Ray-Tracing and Monte Carlo methods was also performed on a lung SBRT case. The RMS between the measured and calculated TPRs is 0.7% averaged for all cones, with the descending region at 0.5%. The RMSs of OCR at infield and outfield regions are both at 0.5%. The distance to agreement (DTA) at the OCR penumbra region is 0.2 mm. All three cone size correction models achieve the same improvement in OCR agreement, with the effective source shift model (SSM) preferred, due to their ability to predict more accurately the OF variations with the source to axis distance (SAD). In noncircular field validation, the pencil beam calculated

  10. Radiation shielding evaluation based on five years of data from a busy CyberKnife center.

    PubMed

    Yang, Jun; Feng, Jing

    2014-11-08

    We examined the adequacy of existing shielding guidelines using five-year clinical data from a busy CyberKnife center. From June 2006 through July 2011, 1,370 patients were treated with a total of 4,900 fractions and 680,691 radiation beams using a G4 CyberKnife. Prescription dose and total monitor units (MU) were analyzed to estimate the shielding workload and modulation factor. In addition, based on the beam's radiation source position, targeting position, MU, and beam collimator size, the MATLAB program was used to project each beam toward the shielding barrier. The summation of the projections evaluates the distribution of the shielding load. On average, each patient received 3.6 fractions, with an average 9.1 Gy per fraction prescribed at the 71.1% isodose line, using 133.7 beams and 6,200 MU. Intracranial patients received an average of 2.7 fractions, with 8.6 Gy per fraction prescribed at the 71.4% isodose line, using 133 beams and 5,083 MU. Extracranial patients received an average of 3.94 fractions, with 9.2 Gy per frac- tion prescribed at the 71% isodose line, using 134 beams and 6,514 MU. Most- used collimator sizes for intracranial patients were smaller (7.5 to 20 mm) than for extracranial patients (20 to 40 mm). Eighty-five percent of the beams exited through the floor, and about 40% of the surrounding wall area received no direct beam. For the rest of the wall, we found "hot" areas that received above-average MU. The locations of these areas were correlated with the projection of the nodes for extracranial treatments. In comparison, the beam projections on the wall were more spread for intracranial treatments. The maximum MU any area received from intracranial treatment was less than 0.25% of total MU used for intracranial treatments, and was less than 1.2% of total MU used for extracranial treatments. The combination of workload, modulation factor, and use factor in our practice are about tenfold less than recommendations in the existing CyberKnife

  11. Reirradiation for recurrent head and neck cancers using charged particle or photon radiotherapy.

    PubMed

    Yamazaki, Hideya; Demizu, Yusuke; Okimoto, Tomoaki; Ogita, Mikio; Himei, Kengo; Nakamura, Satoaki; Suzuki, Gen; Yoshida, Ken; Kotsuma, Tadayuki; Yoshioka, Yasuo; Oh, Ryoongjin

    2017-07-01

    To examine the outcomes of reirradiation for recurrent head and neck cancers using different modalities. This retrospective study included 26 patients who received charged particle radiotherapy (CP) and 150 who received photon radiotherapy (117 CyberKnife radiotherapy [CK] and 36 intensity-modulated radiotherapy [IMRT]). Inverse probability of treatment weighting (IPTW) involving propensity scores was used to reduce background selection bias. Higher prescribed doses were used in CP than photon radiotherapy. The 1‑year overall survival (OS) rates were 67.9% for CP and 54.1% for photon radiotherapy (p = 0.15; 55% for CK and 51% for IMRT). In multivariate Cox regression, the significant prognostic factors for better survival were nasopharyngeal cancer, higher prescribed dose, and lower tumor volume. IPTW showed a statistically significant difference between CP and photon radiotherapy (p = 0.04). The local control rates for patients treated with CP and photon radiotherapy at 1 year were 66.9% (range 46.3-87.5%) and 67.1% (range 58.3-75.9%), respectively. A total of 48 patients (27%) experienced toxicity grade ≥3 (24% in the photon radiotherapy group and 46% in the CP group), including 17 patients with grade 5 toxicity. Multivariate analysis revealed that younger age and a larger planning target volume (PTV) were significant risk factors for grade 3 or worse toxicity. CP provided superior survival outcome compared to photon radiotherapy. Tumor volume, primary site (nasopharyngeal), and prescribed dose were identified as survival factors. Younger patients with a larger PTV experienced toxicity grade ≥3.

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

    PubMed Central

    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. PMID:22655248

  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. Successful CyberKnife Irradiation of 1000 cc Hemicranial Meningioma: 6-year Follow-up

    PubMed Central

    Golanov, Andrey V.; Antipina, Natalia; Gorlachev, Gennady

    2015-01-01

    Meningiomas are common benign tumors with accepted treatment approaches and usually don't challenge healthcare specialists. We present a case of a huge unresectable hemicranial meningioma, which was successfully treated with hypofractionated irradiation. A male patient, sixty-two years of age, suffered for over 12 years from headaches, facial deformity, right eye displacement, right eye movement restriction, right-sided ptosis, and facial hypoesthesia. MRI and CT studies revealed an extended hemicranial meningioma. Prior to irradiation, the patient underwent four operations. Eventually, the tumor was irradiated with the CyberKnife in August 2009. Tumor volume composed 1085 cc. The mean dose of 35.3 Gy was delivered in 7 fractions (31.5 Gy at 72% isodose line comprising 95% of tumor volume). The patient was followed during six years and experienced only mild (Grade 1-2 CTCAE) acute skin and mucosa reactions. During the follow-up period, we observed target volume shrinkage for 17% (for 26% after excluding hyperostosis) and regression of intracranial hypertension signs. Due to the extreme volume and complex shape of the tumor, spreading along the surface of the hemisphere as well as an optic nerve involvement, the case presented would not be generally considered suitable for irradiation, especially for hypofractionation. We regard this clinical situation not as a treatment recommendation, but as a demonstration of the underestimated possibilities of hypofractionation regimen and CyberKnife system, both of which are limited with our habit of conventional treatments. PMID:26719827

  15. Dose distribution transfer from CyberKnife to Varian treatment planning system

    NASA Astrophysics Data System (ADS)

    Osewski, W.; Ślosarek, K.; Karaszewska, B.

    2014-03-01

    The aim of this paper was to introduce one of the options of the locally developed DDcon.exe which gives the possibility to transfer the dose distribution from CyberKnife (Accuray) treatment planning system (CK TPS) to Varian treatment planning system (Eclipse TPS, Varian). DICOM format is known as a universal format for medical data. The dose distribution is stored as RTdose file in DICOM format, so there should be a possibility to transfer it between different treatment planning systems. Trying to transfer RTdose file from CK TPS to Eclipse TPS the error message occurs. That's because the RTdose file in CK TPS is connected with Structure_Set_Sequence against Eclipse TPS where it's connected with RT_Plan_Sequence. To make it transferable RTdose file from CK TPS have to be 'disconnected' from Structure_Set_Sequence and 'connected' with RT_Plan_Sequence. This is possible thanks DDcon software which creates new RTdose file by changing proper DICOM tags in original RTdose file. New homemade software gives us an opportunity to transfer dose distribution from CyberKnife TPS to TPS Eclipse. This method opens new possibilities to combine or compare different treatment techniques in Varian TPS.

  16. Dosimetric characterization of CyberKnife radiosurgical photon beams using polymer gels

    SciTech Connect

    Pantelis, E.; Antypas, C.; Petrokokkinos, L.; Karaiskos, P.; Papagiannis, P.; Kozicki, M.; Georgiou, E.; Sakelliou, L.; Seimenis, I.

    2008-06-15

    Dose distributions registered in water equivalent, polymer gel dosimeters were used to measure the output factors and off-axis profiles of the radiosurgical photon beams employed for CyberKnife radiosurgery. Corresponding measurements were also performed using a shielded silicon diode commonly employed for CyberKnife commissioning, the PinPoint ion chamber, and Gafchromic EBT films, for reasons of comparison. Polymer gel results of this work for the output factors of the 5, 7.5, and 10 mm diameter beams are (0.702{+-}0.029), (0.872{+-}0.039), and (0.929{+-}0.041), respectively. Comparison of polymer gel and diode measurements shows that the latter overestimate output factors of the two small beams (5% for the 5 mm beam and 3% for the 7.5 mm beams). This is attributed to the nonwater equivalence of the high atomic number silicon material of the diode detector. On the other hand, the PinPoint chamber is found to underestimate output factors up to 10% for the 5 mm beam due to volume averaging effects. Polymer gel and EBT film output factor results are found in close agreement for all beam sizes, emphasizing the importance of water equivalence and fine detector sensitive volume for small field dosimetry. Relative off-axis profile results are in good agreement for all dosimeters used in this work, with noticeable differences observed only in the PinPoint estimate of the 80%-20% penumbra width, which is relatively overestimated.

  17. Image guidance quality assurance of a G4 CyberKnife robotic stereotactic radiosurgery system

    NASA Astrophysics Data System (ADS)

    Pantelis, E.; Petrokokkinos, L.; Antypas, C.

    2009-05-01

    The image guidance of a CyberKnife robotic radiosurgery system was quality controlled, including the overall performance of the target locating subsystem and the performance of the x-ray generators and flat panel digital cameras subcomponents. Accuracy and precision of the kV and exposure time settings of the x-ray generators, linearity of the x-ray output, spatial resolution and geometrical distortion of the acquired x-ray images were measured. Total accuracy and precision of the target locating subsystem in defining the position of an anthropomorphic head and neck phantom placed on treatment couch was also measured. Accuracy and precision of the kV as well as exposure time settings and linearity of the x-ray output were found within the acceptance limits suggested in diagnostic radiology. The acquired x-ray images were found to depict the shapes of the imaging objects without any geometrical distortion, being able to resolve differences in the features of imaging objects with critical frequency of 1.3 lp/mm and 1.5 lp/mm for camera A and B, respectively. Total target locating system accuracy was found within 0.2 mm and 0.2° in translations and rotations, respectively. Corresponding precision was found lower than 0.5%. These findings render the target locating subsystem of the CyberKnife capable of accurately registering the patient to treatment position and monitoring patient's movement during treatment delivery.

  18. Automated skull tracking for the CyberKnife image-guided radiosurgery system

    NASA Astrophysics Data System (ADS)

    Fu, Dongshan; Kuduvalli, Gopinath; Mitrovic, Vladimir; Main, William; Thomson, Larry

    2005-04-01

    We have developed an automated skull tracking method to perform near real-time patient alignment and position correction during CyberKnife image-guided intracranial radiosurgery. Digitally reconstructed radiographs (DRRs) are first generated offline from a CT study before treatment, and are used as reference images for the patient position. Two orthogonal projection X-ray images are then acquired at the time of patient alignment or treatment. Multi-phase registration is used to register the DRRs with the X-ray images. The registration in each projection is carried out independently; the results are then combined and converted to a 3-D rigid transformation. The in-plane transformation and the out-of-plane rotations are estimated using different search methods including multi-resolution matching, steepest descent minimization and one-dimensional search. Two similarity measure methods, optimized pattern intensity and sum of squared difference (SSD), are applied at different search phases to optimize both accuracy and computation speed. Experiments on an anthropomorphic skull phantom showed that the tracking accuracy (RMS error) is better than 0.3 mm for each translation and better than 0.3 degree for each rotation, and the targeting accuracy (clinically relevant accuracy) tested with the CyberKnife system is better than 1 mm. The computation time required for the tracking algorithm is within a few seconds.

  19. Successful CyberKnife Irradiation of 1000 cc Hemicranial Meningioma: 6-year Follow-up.

    PubMed

    Galkin, Mikhail; Golanov, Andrey V; Antipina, Natalia; Gorlachev, Gennady

    2015-11-20

    Meningiomas are common benign tumors with accepted treatment approaches and usually don't challenge healthcare specialists. We present a case of a huge unresectable hemicranial meningioma, which was successfully treated with hypofractionated irradiation. A male patient, sixty-two years of age, suffered for over 12 years from headaches, facial deformity, right eye displacement, right eye movement restriction, right-sided ptosis, and facial hypoesthesia. MRI and CT studies revealed an extended hemicranial meningioma. Prior to irradiation, the patient underwent four operations. Eventually, the tumor was irradiated with the CyberKnife in August 2009. Tumor volume composed 1085 cc. The mean dose of 35.3 Gy was delivered in 7 fractions (31.5 Gy at 72% isodose line comprising 95% of tumor volume). The patient was followed during six years and experienced only mild (Grade 1-2 CTCAE) acute skin and mucosa reactions. During the follow-up period, we observed target volume shrinkage for 17% (for 26% after excluding hyperostosis) and regression of intracranial hypertension signs. Due to the extreme volume and complex shape of the tumor, spreading along the surface of the hemisphere as well as an optic nerve involvement, the case presented would not be generally considered suitable for irradiation, especially for hypofractionation. We regard this clinical situation not as a treatment recommendation, but as a demonstration of the underestimated possibilities of hypofractionation regimen and CyberKnife system, both of which are limited with our habit of conventional treatments.

  20. Correlation and prediction uncertainties in the CyberKnife Synchrony respiratory tracking system

    SciTech Connect

    Pepin, Eric W.; Wu, Huanmei; Zhang, Yuenian; Lord, Bryce

    2011-07-15

    Purpose: The CyberKnife uses an online prediction model to improve radiation delivery when treating lung tumors. This study evaluates the prediction model used by the CyberKnife radiation therapy system in terms of treatment margins about the gross tumor volume (GTV). Methods: From the data log files produced by the CyberKnife synchrony model, the uncertainty in radiation delivery can be calculated. Modeler points indicate the tracked position of the tumor and Predictor points predict the position about 115 ms in the future. The discrepancy between Predictor points and their corresponding Modeler points was analyzed for 100 treatment model data sets from 23 de-identified lung patients. The treatment margins were determined in each anatomic direction to cover an arbitrary volume of the GTV, derived from the Modeler points, when the radiation is targeted at the Predictor points. Each treatment model had about 30 min of motion data, of which about 10 min constituted treatment time; only these 10 min were used in the analysis. The frequencies of margin sizes were analyzed and truncated Gaussian normal functions were fit to each direction's distribution. The standard deviation of each Gaussian distribution was then used to describe the necessary margin expansions in each signed dimension in order to achieve the desired coverage. In this study, 95% modeler point coverage was compared to 99% modeler coverage. Two other error sources were investigated: the correlation error and the targeting error. These were added to the prediction error to give an aggregate error for the CyberKnife during treatment of lung tumors. Results: Considering the magnitude of 2{sigma} from the mean of the Gaussian in each signed dimension, the margin expansions needed for 95% modeler point coverage were 1.2 mm in the lateral (LAT) direction and 1.7 mm in the anterior-posterior (AP) direction. For the superior-inferior (SI) direction, the fit was poor; but empirically, the expansions were 3.5 mm

  1. MO-D-BRB-07: Failure-Mode and Effects Analysis Study for CyberKnife Stereotactic Radiosurgery.

    PubMed

    Dieterich, S; Ford, E; Halasz, C

    2012-06-01

    The purpose of this study is to conduct a Failure Modes and Effect Analysis (FMEA) for CyberKnife Stereotactic Radiosurgery to determine the sensitivity of existing QA procedures and determine in which areas new QA procedures needed to be implemented. Members from each professional team providing service for CyberKnife radiosurgery (Medical Physicists, Nurses, Physicians, Radiation Therapists, and Administrators) were interviewed to gather potential failure modes. A patient flow chart was developed from patient consult to conclusion of last treatment. Failure modes were mapped to nodes in the flow charts to identify potential high-risk areas. A matrix was created to correlate existing QA procedures with failure modes to identify failure modes that were not covered by any QA as well as identify the sensitivity of QA procedures to prevent failures. 180 failure modes were identified. Current AAPM QA recommendations were found to focus preferentially on technical failure modes (15%), while the majority of failure modes found are process failures and human errors (85%). Creating a Venn diagram of CyberKnife and Gamma Knife failure modes revealed a large overlap area. The most effective QA checks are checklists for physics second chart review and pre- treatment time-out checklists. Existing checklists were modified and new checklists added to address high-ranked failure modes. New procedure guidelines, e.g. for contouring workflow and add-on simulations, were developed as QC to address clusters of failure modes. An ARIA-CyberKnife DICOM interface is being implemented to resolve failure modes centering around multiple fraction, multiple plan treatments and total dose tracking. This work is the first FMEA study for the CyberKnife stereotactic radiosurgery. It will facilitate medical physicists using the CyberKnife to deliver SRS/SBRT treatments to transition from experience-based technical QA to a comprehensive new quality paradigm including technical, process, and human

  2. [Prostate localization systems for prostate radiotherapy].

    PubMed

    de Crevoisier, R; Lagrange, J-L; Messai, T; M'Barek, B; Lefkopoulos, D

    2006-11-01

    The development of sophisticated conformal radiation therapy techniques for prostate cancer, such as intensity-modulated radiotherapy, implies precise and accurate targeting. Inter- and intrafraction prostate motion can be significant and should be characterized, unless the target volume may occasionally be missed. Indeed, bony landmark-based portal imaging does not provide the positional information for soft-tissue targets (prostate and seminal vesicles) or critical organs (rectum and bladder). In this article, we describe various prostate localization systems used before or during the fraction: rectal balloon, intraprostatic fiducials, ultrasound-based localization, integrated CT/linear accelerator system, megavoltage or kilovoltage cone-beam CT, Calypso 4D localization system tomotherapy, Cyberknife and Exactrac X-Ray 6D. The clinical benefit in using such prostate localization tools is not proven by randomized studies and the feasibility has just been established for some of these techniques. Nevertheless, these systems should improve local control by a more accurate delivery of an increased prescribed dose in a reduced planning target volume.

  3. Virtual HDR{sup SM} CyberKnife Treatment for Localized Prostatic Carcinoma: Dosimetry Comparison With HDR Brachytherapy and Preliminary Clinical Observations

    SciTech Connect

    Fuller, Donald B. Naitoh, John; Lee, Charles; Hardy, Steven C.; Jin, Haoran

    2008-04-01

    Background: We tested our ability to approximate the dose (38 Gy), fractionation (four fractions), and distribution of high-dose-rate (HDR) brachytherapy for prostate cancer with CyberKnife (CK) stereotactic body radiotherapy (SBRT) plans. We also report early clinical observations of CK SBRT treatment. Methods and Materials: Ten patients were treated with CK. For each CK SBRT plan, an HDR plan was designed using common contour sets and simulated HDR catheters. Planning target volume coverage, intraprostatic dose escalation, and urethra, rectum, and bladder exposure were compared. Results: Planning target volume coverage by the prescription dose was similar for CK SBRT and HDR plans, whereas percent of volume of interest receiving 125% of prescribed radiation dose (V125) and V150 values were higher for HDR, reflecting higher doses near HDR source dwell positions. Urethra dose comparisons were lower for CK SBRT in 9 of 10 cases, suggesting that CK SBRT may more effectively limit urethra dose. Bladder maximum point doses were higher with HDR, but bladder dose falloff beyond the maximum dose region was more rapid with HDR. Maximum rectal wall doses were similar, but CK SBRT created sharper rectal dose falloff beyond the maximum dose region. Second CK SBRT plans, constructed by equating urethra radiation dose received by point of maximum exposure of volume of interest to the HDR plan, significantly increased V125 and V150. Clinically, 4-month post-CK SBRT median prostate-specific antigen levels decreased 86% from baseline. Acute toxicity was primarily urologic and returned to baseline by 2 months. Acute rectal morbidity was minimal and transient. Conclusions: It is possible to construct CK SBRT plans that closely recapitulate HDR dosimetry and deliver the plans noninvasively.

  4. SU-E-T-767: Treatment Planning Study of Prostate Cancer by CyberKnife with Respect to the Urethral Dose

    SciTech Connect

    Mizuno, H; Mizuno, H; Sumida, I; Otani, Y; Yagi, M; Takashina, M; Suzuki, O; Yoshioka, Y; Koizumi, M; Ogawa, K

    2015-06-15

    Purpose: Hypo-fractionated stereotactic body radiation therapy (SBRT) with intensity modulated radiation therapy (IMRT) is nowadays one of the treatment strategies for prostate cancer. There are few reports on planning study of prostate cancer by CyberKnife with respect to the urethral dose because of the invisibility in CT. We have investigated a planning method using fixed collimators with considering dose homogeneity, conformity and urethral dose. Methods: Radiotherapy treatment planning of prostate cancer were under a clinical trial approved by the institutional review board. The prescription dose of 35 Gy were delivered to the PTV in five fractions with the urethral catheter. Urethra position was identified by pretreatment CT and catheter, which was inserted before treatment planning CT and released after the treatment. All plans agreed to the criteria as shown in table 1, and the following constraints were recommended as well: the prescribed iso-dose line should be from 70% to 90%; the total MU should be below 50,000 MU; the minimum MU per beam should be larger than 15 MU; the estimated delivery time (excluding patient setup time) by Multiplan with image time interval of 60 s should be less than 35 min. Collimator size and position were decided as shown in figure 1. Fixed collimator of 15 mm was positioned around urethra and PTV for avoiding high dose of urethra and achieving conformity, and fixed collimator of 30 or 40 were positioned around PTV for achieving dose homogeneity. Results: With this method, all constraints were achieved. (Table 1, Figure 2) Max dose of urethra was ranging from 103.9% to 114.2%, because urethra position was identified by pretreatment CT and urethral catheter. Conclusion: Hypo-fractionated SBRT with IMRT utilizing urethral catheter could be a promising new treatment option for prostate cancer. This work was supported by JSPS Core-to-Core program Number 23003.

  5. Analysis of high-dose rate brachytherapy dose distribution resemblance in CyberKnife hypofractionated treatment plans of localized prostate cancer.

    PubMed

    Sudahar, H; Kurup, P G G; Murali, V; Mahadev, P; Velmurugan, J

    2013-01-01

    The present study is to analyze the CyberKnife hypofractionated dose distribution of localized prostate cancer in terms of high-dose rate (HDR) brachytherapy equivalent doses to assess the degree of HDR brachytherapy resemblance of CyberKnife dose distribution. Thirteen randomly selected localized prostate cancer cases treated using CyberKnife with a dose regimen of 36.25Gy in 5 fractions were considered. HDR equivalent doses were calculated for 30Gy in 3 fractions of HDR brachytherapy regimen. The D5% of the target in the CyberKnife hypofractionation was 41.57 ± 2.41Gy. The corresponding HDR fractionation (3 fractions) equivalent dose was 32.81 ± 1.86Gy. The mean HDR fractionation equivalent dose, D98%, was 27.93 ± 0.84Gy. The V100% of the prostate target was 95.57% ± 3.47%. The V100% of the bladder and the rectum were 717.16 and 79.6mm(3), respectively. Analysis of the HDR equivalent dose of CyberKnife dose distribution indicates a comparable resemblance to HDR dose distribution in the peripheral target doses (D98% to D80%) reported in the literature. However, there is a substantial difference observed in the core high-dose regions especially in D10% and D5%. The dose fall-off within the OAR is also superior in reported HDR dose distribution than the HDR equivalent doses of CyberKnife.

  6. Respiratory motion tracking of skin and liver in swine for Cyberknife motion compensation

    NASA Astrophysics Data System (ADS)

    Tang, Jonathan; Dieterich, Sonja; Cleary, Kevin R.

    2004-05-01

    In this study, we collected respiratory motion data of external skin markers and internal liver fiducials from several swine. The POLARIS infrared tracking system was used for recording reflective markers placed on the swine"s abdomen. The AURORA electromagnetic tracking system was used for recording 2 tracked needles implanted into the liver. This data will be used to develop correlation models between external skin movement and internal organ movement, which is the first step towards the ability to compensate for respiratory movement of the lesion. We are also developing a motion simulator for validation of our model and dose verification of mobile lesions in the CYBERKNIFE Suite. We believe that this research could provide significant information towards the development of precise radiation treatment of mobile target volumes.

  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. Evaluation of GAFCHROMIC registered EBT film for CyberKnife registered dosimetry

    SciTech Connect

    Wilcox, Ellen E.; Daskalov, George M.

    2007-06-15

    External beam therapy (EBT) GAFCHROMIC registered film is evaluated for dosimetry and characterization of the CyberKnife registered radiation beams. Percentage depth doses, lateral beam profiles, and output factors are measured in solid water using EBT GAFCHROMIC registered film (International Specialty Products, Wayne, NJ) for the 6 MV radiation beams of diameter 5 to 60 mm produced by the CyberKnife registered (Accuray, Sunnyvale, CA). The data are compared to those measured with the PTW 60008 diode and the Wellhofer CC01 ion chamber in water. For the small radiation field sizes used in stereotactic radiosurgery, lateral electronic disequilibrium and steep dose gradients exist in a large portion of these fields, requiring the use of high-resolution measurement techniques. For small beams, the detector size approaches the dimensions of the beam and adversely affects measurement accuracy in regions where the gradient varies across the detector. When film is the detector, the scanning system is usually the resolution-limiting component. Radiographic films based upon silver halide (AgH) emulsions are widely used for relative dosimetry of external radiation treatment beams in the megavoltage energy range, because of their good spatial resolution and capability to provide integrated dosimetry over two dimensions. Film dosimetry, however, has drawbacks due to its steep energy dependence at low photon energies as well as film processor and densitometer artifacts. EBT radiochromic film, introduced in 2004 specifically for IMRT dosimetry, may be a detector of choice for the characterization of small radiosurgical beams, because of its near-tissue equivalence, radiation beam energy independence, high spatial resolution, and self developing properties. For radiation beam sizes greater than 10 mm, the film measurements were identical to those of the diode and ion chamber. For the smaller beam diameters of 7.5 and 5 mm, however, there were differences in the data measured with

  9. SU-E-T-233: Cyberknife Versus Linac IMRT for Dose Comparision in Hypofractionated Hemi Larynx Irradiation of Early Stage True Vocal Cord Cancer: A Dosimetric Study

    SciTech Connect

    Ding, C; Lee, P; Jiang, S

    2015-06-15

    Purpose: To compare dosimetric data of patients treated for early-stage larynx cancer on Cyberknife and Linac IMRT. Methods: Nine patients were treated with Cyberknife to a dose of 45 Gy in 10 fractions of the involved hemilarynx. The prescription dose provided at least 95% of PTV coverage. After Cyberknife treatment, the CT images and contours were sent to Pinnacle treatment planning system for IMRT planning on a regular SBRT linac with same dose prescription and constrains. Dose to target and normal tissue, including the arytenoids, cord, carotid arteries, thyroid, and skin, were analyzed using dose volume histograms. Results: For Cyberknife plan, the conformity indices are within 1.11–1.33. The average dose to the contralateral arytenoids for Cyberknife plans was 28.9±6.5Gy), which is lower than the same mean dose for IMRT plans (34.0±5.2 Gy). The average maximum dose to the ipsilateral and contralateral carotid artery were 20.6 ±9.1 Gy and 10.2±6.0 Gy respectively for Cybeknife comparing with 22.1±8.0 Gy and 12.0±5.1 Gy for IMRT. The mean dose to the thyroid was 3.6±2.2 Gy for Cyberknife and 3.4±2.4 Gy for IMRT. As shown in DVH, the Cyberknife can deliver less dose to the normal tissue which is close to target area comparing with IMRT Plans. However, IMRT plan’s can give more sparing for the critical organs which is far away from the target area. Conclusion: We have compared the dosimetric parameters of Cyberknife and linac IMRT plans for patients with early-stage larynx cancer. Both Cyberknife and IMRT plans can achieve conformal dose distribution to the target area. Cyberknife was able to reduce normal tissue dose in high doses region while IMRT plans can reduce the dose of the normal tissue at the low dose region. These dosimetric parameters can be used to guide future prospective protocols using SBRT for larynx cancer.

  10. SU-E-T-409: Intensity Modulated Robotic Radiotherapy

    SciTech Connect

    Wang, B; Jin, L; Li, J; Chen, L; Ma, C; Fan, J; Zhang, C

    2014-06-01

    Purpose: As compared with the IRIS-based models, the MLC-based CyberKnife system allows more efficient treatment delivery due to its improved coverage of large lesions and intensity modulation. The treatment delivery efficiency is mainly determined by the number of selected nodes. This study aimed to demonstrate that relatively small sets of optimally selected nodes could produce high-quality plans. Methods: The full body path of the CyberKnife system consists of 110 nodes, from which we selected various sets for 4 prostate cancer cases using our in-house beamselection software. With the selected nodes we generated IMRT plans using our in-house beamlet-based inverse-planning optimization program. We also produced IMRT plans using the MultiPlan treatment planning system (version 5.0) for the same cases. Furthermore, the nodes selected by MultiPlan were used to produce plans with our own optimization software so that we could compare the quality of the selected sets of nodes. Results: Our beam-selection program selected one node-set for each case, with the number of nodes ranging from 23 to 34. The IMRT plans based on the selected nodes and our in-house optimization program showed adequate target coverage, with favorable critical structure sparing for the cases investigated. Compared with the plans using the nodes selected by MultiPlan, the plans generated with our selected beams provided superior rectum/bladder sparing for 75% of the cases. The plans produced by MultiPlan with various numbers of nodes also suggested that the plan quality was not compromised significantly when the number of nodes was reduced. Conclusion: Our preliminary results showed that with beamletbased planning optimization, one could produce high-quality plans with an optimal set of nodes for MLC-based robotic radiotherapy. Furthermore, our beam-selection strategy could help further improve critical structure sparing.

  11. Multicenter evaluation of a synthetic single-crystal diamond detector for CyberKnife small field size output factors.

    PubMed

    Russo, Serenella; Masi, Laura; Francescon, Paolo; Frassanito, Maria Cristina; Fumagalli, Maria Luisa; Marinelli, Marco; Falco, Maria Daniela; Martinotti, Anna Stefania; Pimpinella, Maria; Reggiori, Giacomo; Verona Rinati, Gianluca; Vigorito, Sabrina; Mancosu, Pietro

    2016-04-01

    The aim of the present work was to evaluate small field size output factors (OFs) using the latest diamond detector commercially available, PTW-60019 microDiamond, over different CyberKnife systems. OFs were measured also by silicon detectors routinely used by each center, considered as reference. Five Italian CyberKnife centers performed OFs measurements for field sizes ranging from 5 to 60mm, defined by fixed circular collimators (5 centers) and by Iris(™) variable aperture collimator (4 centers). Setup conditions were: 80cm source to detector distance, and 1.5cm depth in water. To speed up measurements two diamond detectors were used and their equivalence was evaluated. MonteCarlo (MC) correction factors for silicon detectors were used for comparing the OF measurements. Considering OFs values averaged over all centers, diamond data resulted lower than uncorrected silicon diode ones. The agreement between diamond and MC corrected silicon values was within 0.6% for all fixed circular collimators. Relative differences between microDiamond and MC corrected silicon diodes data for Iris(™) collimator were lower than 1.0% for all apertures in the totality of centers. The two microDiamond detectors showed similar characteristics, in agreement with the technical specifications. Excellent agreement between microDiamond and MC corrected silicon diode detectors OFs was obtained for both collimation systems fixed cones and Iris(™), demonstrating the microDiamond could be a suitable detector for CyberKnife commissioning and routine checks. These results obtained in five centers suggest that for CyberKnife systems microDiamond can be used without corrections even at the smallest field size. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  12. SU-F-SPS-10: The Dosimetric Comparison of GammaKnife and Cyberknife Treatment Plans for Brain SRS Treatment

    SciTech Connect

    Sanli, E; Mabhouti, H; Cebe, M; Codel, G; Pacaci, P; Serin, E; Kucuk, N; Kucukmorkoc, E; Doyuran, M; Canoglu, D; Altinok, A; Acar, H; Caglar Ozkok, H

    2016-06-15

    Purpose: Brain stereotactic radiosurgery (SRS) involves the use of precisely directed, single session radiation to create a desired radiobiologic response within the brain target with acceptable minimal effects on surrounding structures or tissues. In this study, the dosimetric comparison of GammaKnife perfection and Cyberknife M6 treatment plans were made. Methods: Treatment plannings were done for GammaKnife perfection unit using Gammaplan treatment planning system (TPS) on the CT scan of head and neck randophantom simulating the treatment of sterotactic treatments for one brain metastasis. The dose distribution were calculated using TMR 10 algorithm. The treatment planning for the same target were also done for Cyberknife M6 machine using Multiplan (TPS) with Monte Carlo algorithm. Using the same film batch, the net OD to dose calibration curve was obtained using both machine by delivering 0- 800 cGy. Films were scanned 48 hours after irradiation using an Epson 1000XL flatbed scanner. Dose distribution were measured using EBT3 film dosimeter. The measured and calculated doses were compared. Results: The dose distribution in the target and 2 cm beyond the target edge were calculated on TPSs and measured using EBT3 film. For cyberknife treatment plans, the gamma analysis passing rates between measured and calculated dose distributions were 99.2% and 96.7% for target and peripheral region of target respectively. For gammaknife treatment plans, the gamma analysis passing rates were 98.9% and 93.2% for target and peripheral region of target respectively. Conclusion: The study shows that dosimetrically comparable plans are achievable with Cyberknife and GammaKnife. Although TMR 10 algorithm predicts the target dose.

  13. Quality of life in the follow-up of uveal melanoma patients after CyberKnife treatment.

    PubMed

    Klingenstein, Annemarie; Fürweger, Christoph; Nentwich, Martin M; Schaller, Ulrich C; Foerster, Paul I; Wowra, Berndt; Muacevic, Alexander; Eibl, Kirsten H

    2013-12-01

    To assess quality of life in uveal melanoma patients within the first and second year after CyberKnife radiosurgery. Overall, 91 uveal melanoma patients were evaluated for quality of life through the Short-form (SF-12) Health Survey at baseline and at every follow-up visit over 2 years after CyberKnife radiosurgery. Statistical analysis was carried out using SF Health Outcomes Scoring Software and included subgroup analysis of patients developing secondary glaucoma and of patients maintaining a best corrected visual acuity (BCVA) of the treated eye of 0.5 log(MAR) or better. Analysis of variance, Greenhouse-Geisser correction, Student's t-test, and Fisher's exact test were used to determine statistical significance. Physical Functioning (PF) and Role Physical (RP) showed a significant decrease after CyberKnife radiosurgery, whereas Mental Health (MH) improved (P=0.007, P<0.0001 and P=0.023). MH and Social Functioning (SF) increased significantly (P=0.0003 and 0.026) in the no glaucoma group, MH being higher compared with glaucoma patients (P=0.02). PF and RP were significantly higher in patients with higher BCVA at the second follow-up (P=0.02). RP decreased in patients with BCVA<0.5 log(MAR) (P=0.013). Vitality (VT) increased significantly in patients whose BCVA could be preserved (P=0.031). Neither tumor localization nor size influenced the development of secondary glaucoma or change in BCVA. Although PF and RP decreased over time, MH improved continuously. Prevention of secondary glaucoma has a significant influence on both SF and MH, whereas preservation of BCVA affects VT. Emotional stability throughout follow-up contributes positively toward overall quality of life. CyberKnife radiosurgery may contribute to attenuation of emotional distress in uveal melanoma patients.

  14. [Image-guided radiotherapy: rational, modalities and results].

    PubMed

    de Crevoisier, R; Louvel, G; Cazoulat, G; Leseur, J; Lafond, C; Lahbabi, K; Chira, C; Lagrange, J-L

    2009-01-01

    The objective of Image-Guided Radiotherapy (IGRT) is to take in account the inter- or/and intrafraction anatomic variations (organ motion and deformations) in order to improve treatment accuracy. The IGRT should therefore translate in a clinical benefit the recent advances in both tumor definition thanks to functional imaging, and dose distribution thanks to intensity modulated radiotherapy. The IGRT enables direct or indirect tumor visualization during radiation delivery. If the tumor position does not correspond with the theoretical location of target derived from planning system, the table is moved. In case of important uncertainties related to target deformation, a new planning can be discussed. IGRT is realized by different types of devices which can vary in principle and as well as in their implementation: from LINAC-integrated-kV (or MV)-Cone Beam CTs to helicoidal tomotherapy, Cyberknife and Novalis low-energy stereoscopic imaging system. These techniques led to a more rational choice of Planning Target Volume. Being recently introduced in practice, the clinical results of this technique are still limited. Nevertheless, until so far, IGRT has showed promising results with reports of minimal acute toxicity. This review describes IGRT for various tumor localizations. The dose delivered by on board imaging should be taken in account. A strong quality control is required for safety and proper prospective evaluation of the clinical benefit of IGRT.

  15. A cross sectional review of patient information available in the World Wide Web on CyberKnife: fallacies and pitfalls.

    PubMed

    Menon, Durgapoorna; Chelakkot, Prameela G; Sunil, Devika; Lakshmaiah, Ashwini

    2017-07-05

    The purpose of this study is to assess the quality of videos available in YouTube on CyberKnife. The term "CyberKnife" was input into the search window of www.youtube.com on a specific date and the first 50 videos were assessed for technical and content issues. The data was tabulated and analysed. The search yielded 32,300 videos in 0.33 s. Among the first 50 analysed, most were professional videos, mostly on CyberKnife in general and for brain tumours. Most of the videos did not mention anything about patient selection or lesion size. The other technical details were covered by most although they seemed muffled by the animations. Many patient videos were recordings of one entire treatment, thus giving future patients an insight on what to expect. Almost half the videos projected glorified views about the treatment technique. The company videos were reasonably accurate and well presented as were many institutional videos, although there was a tendency to gloss over a few points. The glorification of the treatment technique was a disturbing finding. The profound trust of the patients on the health care system is humbling.

  16. CyberKnife with Tumor Tracking: An Effective Treatment for High-Risk Surgical Patients with Single Peripheral Lung Metastases.

    PubMed

    Snider, James W; Oermann, Eric K; Chen, Viola; Rabin, Jennifer; Suy, Simeng; Yu, Xia; Vahdat, Saloomeh; Collins, Sean P; Banovac, Filip; Anderson, Eric; Collins, Brian T

    2012-01-01

    Standard treatment for operable patients with single peripheral lung metastases is metastasectomy. We report mature CyberKnife outcomes for high-risk surgical patients with biopsy proven single peripheral lung metastases. Twenty-four patients (median age 73 years) with a mean maximum tumor diameter of 2.5 cm (range, 0.8-4.5 cm) were treated over a 6-year period extending from September 2004 to September 2010 and followed for a minimum of 1 year or until death. A mean dose of 52 Gy (range, 45-60 Gy) was delivered to the prescription isodose line in three fractions over a 3-11 day period (mean, 7 days). At a median follow-up of 20 months, the 2-year Kaplan-Meier local control and overall survival rates were 87 and 50%, respectively. CyberKnife with fiducial tracking is an effective treatment for high-risk surgical patients with single small peripheral lung metastases. Trials comparing CyberKnife with metastasectomy for operable patients are necessary to confirm equivalence.

  17. Fiducial migration following small peripheral lung tumor image-guided CyberKnife stereotactic radiosurgery

    NASA Astrophysics Data System (ADS)

    Strulik, Konrad L.; Cho, Min H.; Collins, Brian T.; Khan, Noureen; Banovac, Filip; Slack, Rebecca; Cleary, Kevin

    2008-03-01

    To track respiratory motion during CyberKnife stereotactic radiosurgery in the lung, several (three to five) cylindrical gold fiducials are implanted near the planned target volume (PTV). Since these fiducials remain in the human body after treatment, we hypothesize that tracking fiducial movement over time may correlate with the tumor response to treatment and pulmonary fibrosis, thereby serving as an indicator of treatment success. In this paper, we investigate fiducial migration in 24 patients through examination of computed tomography (CT) volume images at four time points: pre-treatment, three, six, and twelve month post-treatment. We developed a MATLAB based GUI environment to display the images, identify the fiducials, and compute our performance measure. After we semi-automatically segmented and detected fiducial locations in CT images of the same patient over time, we identified them according to their configuration and introduced a relative performance measure (ACD: average center distance) to detect their migration. We found that the migration tended to result in a movement towards the fiducial center of the radiated tissue area (indicating tumor regression) and may potentially be linked to the patient prognosis.

  18. Analysis of high–dose rate brachytherapy dose distribution resemblance in CyberKnife hypofractionated treatment plans of localized prostate cancer

    SciTech Connect

    Sudahar, H.; Kurup, P.G.G.; Murali, V.; Mahadev, P.; Velmurugan, J.

    2013-01-01

    The present study is to analyze the CyberKnife hypofractionated dose distribution of localized prostate cancer in terms of high–dose rate (HDR) brachytherapy equivalent doses to assess the degree of HDR brachytherapy resemblance of CyberKnife dose distribution. Thirteen randomly selected localized prostate cancer cases treated using CyberKnife with a dose regimen of 36.25 Gy in 5 fractions were considered. HDR equivalent doses were calculated for 30 Gy in 3 fractions of HDR brachytherapy regimen. The D{sub 5%} of the target in the CyberKnife hypofractionation was 41.57 ± 2.41 Gy. The corresponding HDR fractionation (3 fractions) equivalent dose was 32.81 ± 1.86 Gy. The mean HDR fractionation equivalent dose, D{sub 98%}, was 27.93 ± 0.84 Gy. The V{sub 100%} of the prostate target was 95.57% ± 3.47%. The V{sub 100%} of the bladder and the rectum were 717.16 and 79.6 mm{sup 3}, respectively. Analysis of the HDR equivalent dose of CyberKnife dose distribution indicates a comparable resemblance to HDR dose distribution in the peripheral target doses (D{sub 98%} to D{sub 80%}) reported in the literature. However, there is a substantial difference observed in the core high-dose regions especially in D{sub 10%} and D{sub 5%}. The dose fall-off within the OAR is also superior in reported HDR dose distribution than the HDR equivalent doses of CyberKnife.

  19. [Radiotherapy of bone metastases].

    PubMed

    Thureau, S; Vieillard, M-H; Supiot, S; Lagrange, J-L

    2016-09-01

    Radiotherapy plays a major role in palliative treatment of bone metastases. Recent developments of stereotactic radiotherapy and intensity modulated radiation therapy give the possibility to treat oligometastatic diseases. The objective of this paper is to report indications and treatment modalities of radiotherapy in these situations.

  20. SU-E-J-199: Evaluation of Motion Tracking Effects On Stereotactic Body Radiotherapy of Abdominal Targets

    SciTech Connect

    Monterroso, M; Dogan, N; Yang, Y

    2014-06-01

    Purpose: To evaluate the effects of respiratory motion on the delivered dose distribution of CyberKnife motion tracking-based stereotactic body radiotherapy (SBRT) of abdominal targets. Methods: Four patients (two pancreas and two liver, and all with 4DCT scans) were retrospectively evaluated. A plan (3D plan) using CyberKnife Synchrony was optimized on the end-exhale phase in the CyberKnife's MultiPlan treatment planning system (TPS), with 40Gy prescribed in 5 fractions. A 4D plan was then created following the 4D planning utility in the MultiPlan TPS, by recalculating dose from the 3D plan beams on all 4DCT phases, with the same prescribed isodose line. The other seven phases of the 4DCT were then deformably registered to the end-exhale phase for 4D dose summation. Doses to the target and organs at risk (OAR) were compared between 3D and 4D plans for each patient. The mean and maximum doses to duodenum, liver, spinal cord and kidneys, and doses to 5cc of duodenum, 700cc of liver, 0.25cc of spinal cord and 200cc of kidneys were used. Results: Target coverage in the 4D plans was about 1% higher for two patients and about 9% lower in the other two. OAR dose differences between 3D and 4D varied among structures, with doses as much as 8.26Gy lower or as much as 5.41Gy higher observed in the 4D plans. Conclusion: The delivered dose can be significantly different from the planned dose for both the target and OAR close to the target, which is caused by the relative geometry change while the beams chase the moving target. Studies will be performed on more patients in the future. The differences of motion tracking versus passive motion management with the use of internal target volumes will also be investigated.

  1. 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.

  2. Real time tracking in liver SBRT: comparison of CyberKnife and Vero by planning structure-based γ-evaluation and dose-area-histograms.

    PubMed

    Sothmann, T; Blanck, O; Poels, K; Werner, R; Gauer, T

    2016-02-21

    The purpose of this study was to evaluate and compare two clinical tracking systems for radiosurgery with regard to their dosimetric and geometrical accuracy in liver SBRT: the robot-based CyberKnife and the gimbal-based Vero. Both systems perform real-time tumour tracking by correlating internal tumour and external surrogate motion. CyberKnife treatment plans were delivered to a high resolution 2D detector array mounted on a 4D motion platform, with the platform simulating (a) tumour motion trajectories extracted from the corresponding CyberKnife predictor log files and (b) the tumour motion trajectories with superimposed baseline-drift. Static reference and tracked dose measurements were compared and dosimetric as well as geometrical uncertainties analyzed by a planning structure-based evaluation. For (a), γ-passing rates inside the CTV (γ-criteria of 1% / 1 mm) ranged from 95% to 100% (CyberKnife) and 98% to 100% (Vero). However, dosimetric accuracy decreases in the presence of the baseline-drift. γ-passing rates for (b) ranged from 26% to 92% and 94% to 99%, respectively; i.e. the effect was more pronounced for CyberKnife. In contrast, the Vero system led to maximum dose deviations in the OAR between  +1.5 Gy to +6.0 Gy (CyberKnife: +0.5 Gy to +3.5 Gy). Potential dose shifts were interpreted as motion-induced geometrical tracking errors. Maximum observed shift ranges were  -1.0 mm to  +0.7 mm (lateral) /-0.6 mm to +0.1 mm (superior-inferior) for CyberKnife and  -0.8 mm to +0.2 mm /-0.8 mm to +0.4 mm for Vero. These values illustrate that CyberKnife and Vero provide high precision tracking of regular breathing patterns. Even for the modified motion trajectory, the obtained dose distributions appear to be clinical acceptable with regard to literature QA γ-criteria of 3% / 3 mm.

  3. SU-E-T-330: Dosimetric Impact of Intrafraction Respiratory Motion On Lung SBRT Treatment Using Cyberknife 0-View Tracking Mode

    SciTech Connect

    Rao, M; Chen, F; Cotrutz, C; Ye, J

    2015-06-15

    Purpose: To investigate the influence of respiratory motion on the delivered dose in lung stereotactic body radiotherapy (SBRT) using Cyberknife (CK) 0-View tracking mode. Methods: CT scans at inspiration and expiration of an anthropomorphic motion phantom were fused base on the spine and an internal target volume (ITV) was created. A 5mm expansion around the ITV resulted in the planning target volume. Three CK plans were generated in Accuray MultiPlan using Lung Optimization Tracking 0-View technique with the minimum MU per beam set to (a) 5MU, (b) 15MU and (c) 30MU, respectively. Doses were calculated on the expiration CT using Monte-Carlo algorithm. Each plan was delivered 5 times with a range of different starting phases in the respiratory cycle to assess the dose variation due to interplay effect. The delivered dose was measured with EBT3 Gafchromic film which was inserted in the moving target of the phantom. The target motion range is 3 cm in superior-inferior (SI) direction with the breathing period of 5 seconds. Results: The gamma analysis (5%/2mm) of the dose with the films in the transverse plane resulted in average passing rate of 95.5±4.1%, 96.7±2.6%, and 96.2±2.5% for plan (a), (b), and (c), respectively. For the sagittal films, the average passing rate was 91.1±4.9%, 92.1±3.6%, and 92.3±2.9% for the three plans, respectively. The disagreement between measurement and dose calculations were mostly on the target edges in SI direction. The mean measured versus calculated dose differences at the edge of target in SI direction were (a) 3.9±4.8%, (b) 2.4±3.3%, and (c) 2.2±3.2% for the three plans, respectively. Conclusions: The plans with low-MU beams (below 10MU) tend to cause slightly larger dose variation. However in terms of target coverage, the overall clinical dosimetric impact of the intrafraction respiratory motion in lung SBRT is insignificant when averaged over 3∼5 fractions.

  4. SU-E-T-253: Development of a GDPM Monte Carlo Based Quality Assurance Tool for Cyberknife

    SciTech Connect

    Webster, M; Ouyang, L; Folkerts, M; Tian, Z; Jia, X; Jiang, S; Gu, X

    2015-06-15

    Purpose: To develop a 3D quality assurance (QA) tool for Cyberknife plans using a GPU-based Monte Carlo dose calculation package, gDPM. The developed QA tool will be used as a secondary check for Cyberknife treatment planning software (TPS) reported dose distributions. Methods: Phase space files of the 5, 7.5, 10, 15, and 60 mm iris cones were downloaded from IAEA phase-space database. From the 60mm iris cone phase space file, we were able to generate raw phase space files for all other cones using a particle rejection method. The particles in the raw phase space files were binned with respect to the radial position and energy for commissioning. During the commissioning process, gDPM calculated percent depth dose and off-center ratios which were compared to those measured in the Blue Phantom. The off-axis data was measured with an SAD setup at depths of 15, 50, 100, 200, and 300 mm. At the commissioning stage, an optimization problem was solved to adjust the binned particles weights to minimize the difference between the calculated and measured ones. Commissioning validations will be performed by measuring point dose data of patient specific plans delivered to water phantoms. With commissioned phase space files, 3D patient-specific dose distributions will be calculated and compared against TPS reported dose. Results: Beyond the initial buildup region, the root mean square difference between the calculated and measured percent depth dose differences was less than 0.5%. The full-width half-max data from the off-axis ratio calculations was found to be within 0.1 mm of the measured data. Conclusion: Our current work showed excellent agreement between the gDPM calculated dose and the measured data for all cone sizes and types for the Cyberknife system. Implementation of a fast and accurate QA tool for patient specific plans will be feasible with this tool.

  5. SU-E-T-228: Liquid Ionisation Chamber Array and MicroDiamond Measurements with the CyberKnife System

    SciTech Connect

    Poppinga, D; Looe, H; Stelljes, T; Poppe, B; Blanck, O; Harder, D

    2014-06-01

    Purpose: The aim of this study was to measure the dose profile and output factors with a CyberKnife accelerator using a TM60019 microDiamond detector and a 1000SRS liquid chamber array (both PTW Freiburg, Germany). Methods: An MP3 water phantom (PTW, Freiburg) was positioned along the robotic world coordinate system. The TM60019 detector was adjusted to the center of the according fields and the semiconductor axis was aligned with the beam direction. Profiles at 5cm water depth and SSD = 80 cm were measured along the robotic x axis and y axis for the cylindrical collimators of the CyberKnife (diameter 60, 50, 40, 30, 20, 15, 12.5, 10, 7.5 and 5mm). To determine the output factors the dose profile was measured at 0.1 mm steps around the field center to find the maximum dose value. The liquid chamber array (1000SRS) measurement was performed with the same setup, but with RW3 buildup. Results: The 1000SRS measurements closely conform with the TM60019 profile measurement in all profile regions and for all collimator sizes. The profile measurement is influenced by the almost equal spatial resolution of the TM60019 detector (radius of the sensitive area 1.1mm) and of the 1000SRS liquid chamber array (single chamber width 2.3mm). The measured dose profiles have not been corrected for this limited spatial resolution. Rather we purpose to consider that spatial dose averaging over 2 mm wide regions might be justified in view of patient positioning inaccuracies and of the spaces in tissue participating in the biological radiation responses. Conclusion: The 1000SRS data points conform with the TM60019 profile measurements at all profile regions showing the applicability of liquid ion chamber arrays with the CyberKnife system.

  6. SU-E-T-404: Evaluation of the Effect of Spine Hardware for CyberKnife Spinal Stereotactic Radiosurgery

    SciTech Connect

    Yuan, J; Zhang, Y; Zheng, Y; Wessels, B; Machtay, M; Yao, M; Lo, S

    2015-06-15

    Purpose: Spine hardware made of high-Z materials such as titanium has the potential to affect the dose distribution around the metal rods in CyberKnife spinal stereotactic radiosurgery (SRS) treatments. The purpose of this work was to evaluate the magnitude of such effect retrospectively for clinical CyberKnife plans. Methods: The dose calculation was performed within the MultiPlan treatment planning system using the ray tracing (RT) and Monte Carlo (MC) method. A custom density model was created by extending the CT-to-Density table to titanium density of 4.5 g/cm3 with the CT number of 4095. To understand the dose perturbation caused by the titanium rod, a simple beam setup (7.5 mm IRIS collimator) was used to irradiate a mimic rod (5 mm) with overridden high density. Five patient spinal SRS cases were found chronologically from 2010 to 2015 in our institution. For each case, the hardware was contoured manually. The original plan was re-calculated using both RT and MC methods with and without rod density override without changing clinical beam parameters. Results: The simple beam irradiation shows that there is 10% dose increase at the interface because of electron backscattering and 7% decrease behind the rod because of photon attenuation. For actual clinical plans, the iso-dose lines and DVHs are almost identical (<2%) for calculations with and without density override for both RT and MC methods. However, there is a difference of more than 10% for D90 between RT and MC method. Conclusion: Although the dose perturbation around the metal rods can be as large as 10% for a single beam irradiation, for clinical treatments with complex beam composition the effect of spinal hardware to the PTV and spinal dose is minimal. As such, the MC dose algorithm without rod density override for CyberKnife spinal SRS is acceptable.

  7. Comparative Analysis of Neural Network Training Methods in Real-time Radiotherapy.

    PubMed

    Nouri, S; Hosseini Pooya, S M; Soltani Nabipour, J

    2017-03-01

    The motions of body and tumor in some regions such as chest during radiotherapy treatments are one of the major concerns protecting normal tissues against high doses. By using real-time radiotherapy technique, it is possible to increase the accuracy of delivered dose to the tumor region by means of tracing markers on the body of patients. This study evaluates the accuracy of some artificial intelligence methods including neural network and those of combination with genetic algorithm as well as particle swarm optimization (PSO) estimating tumor positions in real-time radiotherapy. One hundred recorded signals of three external markers were used as input data. The signals from 3 markers thorough 10 breathing cycles of a patient treated via a cyber-knife for a lung tumor were used as data input. Then, neural network method and its combination with genetic or PSO algorithms were applied determining the tumor locations using MATLAB© software program. The accuracies were obtained 0.8%, 12% and 14% in neural network, genetic and particle swarm optimization algorithms, respectively. The internal target volume (ITV) should be determined based on the applied neural network algorithm on training steps.

  8. SU-E-T-258: Parallel Optimization of Beam Configurations for CyberKnife Treatments

    SciTech Connect

    Viulet, T; Blanck, O; Schlaefer, A

    2014-06-01

    Purpose: The CyberKnife delivers a large number of beams originating at different non-planar positions and with different orientation. We study how much the quality of treatment plans depends on the beams considered during plan optimization. Particularly, we evaluate a new approach to search for optimal treatment plans in parallel by running optimization steps concurrently. Methods: So far, no deterministic, complete and efficient method to select the optimal beam configuration for robotic SRS/SBRT is known. Considering a large candidate beam set increases the likelihood to achieve a good plan, but the optimization problem becomes large and impractical to solve. We have implemented an approach that parallelizes the search by solving multiple linear programming problems concurrently while iteratively resampling zero weighted beams. Each optimization problem contains the same set of constraints but different variables representing candidate beams. The search is synchronized by sharing the resulting basis variables among the parallel optimizations. We demonstrate the utility of the approach based on an actual spinal case with the objective to improve the coverage. Results: The objective function is falling and reaches a value of 5000 after 49, 31, 25 and 15 iterations for 1, 2, 4, and 8 parallel processes. This corresponds to approximately 97% coverage in 77%, 59%, and 36% of the mean number of iterations with one process for 2, 4, and 8 parallel processes, respectively. Overall, coverage increases from approximately 91.5% to approximately 98.5%. Conclusion: While on our current computer with uniform memory access the reduced number of iterations does not translate into a similar speedup, the approach illustrates how to effectively parallelize the search for the optimal beam configuration. The experimental results also indicate that for complex geometries the beam selection is critical for further plan optimization.

  9. Optimized treatment with RF thermotherapy and immunotherapy combined with CyberKnife for advanced high-risk tumors: A clinical trial report.

    PubMed

    Jiang, Zhigao; Wang, Qinwen; Yang, Guiqing; Liu, Xiaoxu; Sun, Dongning; Wang, Shanshan; Li, Yang; Wang, Yishan

    2014-03-01

    This study was conducted to evaluate the application value of optimized treatment with radiofrequency (RF) thermotherapy and immunotherapy combined with CyberKnife for advanced high-risk tumors. The database of 1,013 patients with 2,136 tumor lesions and 1,237 target areas who underwent treatment with CyberKnife between November, 2010 and November, 2012, was retrospectively reviewed. We randomly assigned 505 eligible patients (observation group) to RF thermotherapy and adoptive immunotherapy with cytokine-induced killer cells and the remaining 508 patients (control group) to no adjuvant treatment. The patients in the two groups were recorded on efficacy assessment according to imageological examination, World Health Organization criteria, Karnofsky performance status, or radioimmunoassay (RIA) detection. The effective rate of the observation group was 75.05%, whereas that of the control group was 58.06% (P<0.05). The results revealed that CyberKnife combined with hyperthermia and biological therapy are highly effective in improving the local tumor control rate. Further analysis of the Karnofsky score and RIA detection confirmed that this type of combination therapy significantly improved the quality of life. The optimized treatment of RF thermotherapy and immunotherapy combined with CyberKnife may act synergistically in eliminating tumor cells, confirming the efficacy of this type of treatment for patients with advanced malignant tumors.

  10. Dose Calculation Accuracy of the Monte Carlo Algorithm for CyberKnife Compared with Other Commercially Available Dose Calculation Algorithms

    SciTech Connect

    Sharma, Subhash; Ott, Joseph Williams, Jamone; Dickow, Danny

    2011-01-01

    Monte Carlo dose calculation algorithms have the potential for greater accuracy than traditional model-based algorithms. This enhanced accuracy is particularly evident in regions of lateral scatter disequilibrium, which can develop during treatments incorporating small field sizes and low-density tissue. A heterogeneous slab phantom was used to evaluate the accuracy of several commercially available dose calculation algorithms, including Monte Carlo dose calculation for CyberKnife, Analytical Anisotropic Algorithm and Pencil Beam convolution for the Eclipse planning system, and convolution-superposition for the Xio planning system. The phantom accommodated slabs of varying density; comparisons between planned and measured dose distributions were accomplished with radiochromic film. The Monte Carlo algorithm provided the most accurate comparison between planned and measured dose distributions. In each phantom irradiation, the Monte Carlo predictions resulted in gamma analysis comparisons >97%, using acceptance criteria of 3% dose and 3-mm distance to agreement. In general, the gamma analysis comparisons for the other algorithms were <95%. The Monte Carlo dose calculation algorithm for CyberKnife provides more accurate dose distribution calculations in regions of lateral electron disequilibrium than commercially available model-based algorithms. This is primarily because of the ability of Monte Carlo algorithms to implicitly account for tissue heterogeneities, density scaling functions; and/or effective depth correction factors are not required.

  11. Dose calculation accuracy of the Monte Carlo algorithm for CyberKnife compared with other commercially available dose calculation algorithms.

    PubMed

    Sharma, Subhash; Ott, Joseph; Williams, Jamone; Dickow, Danny

    2011-01-01

    Monte Carlo dose calculation algorithms have the potential for greater accuracy than traditional model-based algorithms. This enhanced accuracy is particularly evident in regions of lateral scatter disequilibrium, which can develop during treatments incorporating small field sizes and low-density tissue. A heterogeneous slab phantom was used to evaluate the accuracy of several commercially available dose calculation algorithms, including Monte Carlo dose calculation for CyberKnife, Analytical Anisotropic Algorithm and Pencil Beam convolution for the Eclipse planning system, and convolution-superposition for the Xio planning system. The phantom accommodated slabs of varying density; comparisons between planned and measured dose distributions were accomplished with radiochromic film. The Monte Carlo algorithm provided the most accurate comparison between planned and measured dose distributions. In each phantom irradiation, the Monte Carlo predictions resulted in gamma analysis comparisons >97%, using acceptance criteria of 3% dose and 3-mm distance to agreement. In general, the gamma analysis comparisons for the other algorithms were <95%. The Monte Carlo dose calculation algorithm for CyberKnife provides more accurate dose distribution calculations in regions of lateral electron disequilibrium than commercially available model-based algorithms. This is primarily because of the ability of Monte Carlo algorithms to implicitly account for tissue heterogeneities, density scaling functions; and/or effective depth correction factors are not required.

  12. Real time tracking in liver SBRT: comparison of CyberKnife and Vero by planning structure-based γ-evaluation and dose-area-histograms

    NASA Astrophysics Data System (ADS)

    Sothmann, T.; Blanck, O.; Poels, K.; Werner, R.; Gauer, T.

    2016-02-01

    The purpose of this study was to evaluate and compare two clinical tracking systems for radiosurgery with regard to their dosimetric and geometrical accuracy in liver SBRT: the robot-based CyberKnife and the gimbal-based Vero. Both systems perform real-time tumour tracking by correlating internal tumour and external surrogate motion. CyberKnife treatment plans were delivered to a high resolution 2D detector array mounted on a 4D motion platform, with the platform simulating (a) tumour motion trajectories extracted from the corresponding CyberKnife predictor log files and (b) the tumour motion trajectories with superimposed baseline-drift. Static reference and tracked dose measurements were compared and dosimetric as well as geometrical uncertainties analyzed by a planning structure-based evaluation. For (a), γ-passing rates inside the CTV (γ-criteria of 1% / 1 mm) ranged from 95% to 100% (CyberKnife) and 98% to 100% (Vero). However, dosimetric accuracy decreases in the presence of the baseline-drift. γ-passing rates for (b) ranged from 26% to 92% and 94% to 99%, respectively; i.e. the effect was more pronounced for CyberKnife. In contrast, the Vero system led to maximum dose deviations in the OAR between  +1.5 Gy to  +6.0 Gy (CyberKnife:  +0.5 Gy to  +3.5 Gy). Potential dose shifts were interpreted as motion-induced geometrical tracking errors. Maximum observed shift ranges were  -1.0 mm to  +0.7 mm (lateral) /-0.6 mm to  +0.1 mm (superior-inferior) for CyberKnife and  -0.8 mm to  +0.2 mm /-0.8 mm to  +0.4 mm for Vero. These values illustrate that CyberKnife and Vero provide high precision tracking of regular breathing patterns. Even for the modified motion trajectory, the obtained dose distributions appear to be clinical acceptable with regard to literature QA γ-criteria of 3% / 3 mm.

  13. SU-E-T-516: Measurement of the Absorbed Dose Rate in Water Under Reference Conditions in a CyberKnife Unit

    SciTech Connect

    Aragon-Martinez, N; Hernandez-Guzman, A; Gomez-Munoz, A; Massillon-JL, G

    2014-06-01

    Purpose: This paper aims to measure the absorbed-dose-rate in a CyberKnife unit reference-field (6cm diameter) using three ionization chambers (IC) following the new IAEA/AAPM formalism and Gafchromic film (MD-V3-55 and EBT3) protocol according to our work reported previously. Methods: The absorbed-dose-rates were measured at 90cm and 70cm SSD in a 10cmx10cm field and at 70cm SSD in a 5.4cmx5.4cm equivalent to 6cm diameter field using a linac Varian iX. All measurements were performed at 10cm depth in water. The correction factors that account for the difference between the IC response on the reference field and the CyberKnife reference field, k-(Q-msr,Q)^(f-msr,f-ref), were evaluated and Gafchromic film were calibrated using the results obtained above. Under the CyberKnife reference conditions, the factors were used to measure the absorbed-dose-rate with IC according to the new formalism and the calibrated film was irradiated in water. The film calibration curve was used to evaluate the absorbed-dose-rate in the CyberKnife unit. Results: Difference up to 2.56% is observed between dose-rate measured with IC in the reference 10cmx10cm field, depending where the chamber was calibrated, which was not reflected in the correction factor k-(Q-msr,Q)^(f-msr,f-ref ) where variations of ~0.15%-0.5% were obtained. Within measurements uncertainties, maximum difference of 1.8% on the absorbed-dose-rate in the CyberKnife reference field is observed between all IC and the films Conclusion: Absorbed-dose-rate to water was measured in a CyberKnife reference field with acceptable accuracy (combined uncertainties ~1.32%-1.73%, k=1) using three IC and films. The MD-V3-55 film as well as the new IAEA/AAPM formalism can be considered as a suitable dosimetric method to measure absorbed-dose-rate to water in small and non-standard CyberKnife fields used in clinical treatments However, the EBT3 film is not appropriated due to the high uncertainty provided (combined uncertainty ~9%, k=1

  14. [Radiotherapy of hypopharynx cancers].

    PubMed

    Pointreau, Y; Lafond, C; Trémolières, P; Legouté, F; Servagi-Vernat, S; Giraud, P; Maingon, P; Calais, G; Lapeyre, M

    2016-09-01

    The intensity-modulated radiotherapy is the gold standard in the treatment of hypopharynx cancers. Early T1 and T2 tumours could be treated by exclusive radiotherapy or surgery. For tumours requiring total pharyngolaryngectomy (T2 or T3), induction chemotherapy followed by exclusive radiotherapy or concurrent chemoradiotherapy are possible. For T4 tumours, surgery must be proposed. The treatment of lymph nodes is based on the initial treatment of the primary tumour. In non-surgical procedure, in case of sequential radiotherapy, curative dose is 70Gy and prophylactic dose is 50Gy. An integrated simultaneous boost radiotherapy is allowed (70Gy in 2Gy per fraction and 56Gy in 1.8Gy per fraction or 70Gy in 2.12Gy per fraction). Postoperatively, radiotherapy is used for locally advanced cancers with dose levels based on pathologic criteria (66Gy for R1 resection, 50 to 54Gy for complete resection). Volume delineation is based on guidelines.

  15. Heavy-ion radiotherapy

    NASA Astrophysics Data System (ADS)

    Kanai, Tatsuaki

    2000-11-01

    Heavy-ion radiotherapy using high-energy carbon beams has been performed at the National Institute of Radiological Sciences, Japan. The physical frame works for heavy-ion radiotherapy are established using physical understandings of radiation physics. In order to increase the accuracy of heavy-ion radiotherapy, many physical problems should be solved. Unsolved problems, such as the depth dose distributions, range of heavy-ion in patients and heavy-ion dosimetry in the radiation therapy, are discussed. .

  16. [Radiotherapy of oropharynx carcinoma].

    PubMed

    Servagi Vernat, S; Tochet, F; Vieillevigne, L; Pointreau, Y; Maingon, P; Giraud, P

    2016-09-01

    Indication, doses, technique of radiotherapy and concomitant chemotherapy for oropharynx carcinoma are presented. The recommendations for delineation of the target volumes and organs at risk are detailed.

  17. Effects of initial electron beam parameters of a linear accelerator on the properties of bremsstrahlung radiation in a radiotherapy setting

    NASA Astrophysics Data System (ADS)

    Gorlachev, G. E.; Polozov, S. M.; Dalechina, A. V.; Ksenofontov, A. I.; Kistenev, A. V.

    2016-12-01

    The dependence of the initial electron-beam parameters on absorbed dose distributions have been investigated using a CyberKnife radiotherapy accelerator (Accuray, United States). To describe the initial electron-beam characteristics, simulations of the linear electron accelerator are performed and the electron distributions in the beam of a linac output are analyzed. The radial distributions of electrons are assumed exponential, whereas the energy electron distributions are approximated by monoenergetic and rectangular spectra. There is no significant dependence of depth-dose curves in a phantom on the shape of the electron beam. Importantly, a clear dependence of the radiation field profile on the size of the electron beam is observed not just in the penumbra region, but also in the open part.

  18. Treatment outcomes in patients treated with CyberKnife radiosurgery for vestibular schwannoma.

    PubMed

    Vivas, Esther X; Wegner, Rodney; Conley, George; Torok, Jordan; Heron, Dwight E; Kabolizadeh, Peyman; Burton, Steven; Ozhasoglu, Cihat; Quinn, Annette; Hirsch, Barry E

    2014-01-01

    To evaluate tumor control, hearing, tinnitus, and balance outcomes of patients treated with CyberKnife (CK) radiosurgery for vestibular schwannoma (VS). Retrospective series review. Tertiary referral center. All patients treated with CK radiosurgery for vestibular schwannoma by a multidisciplinary radiosurgical team from August 2005 to November 2011. The median age was 59 years, and mean follow-up was 40 months. Seventy-three patients were treated (63 primary radiosurgery and 10 postsurgical). CK radiosurgery, serial MRI imaging, comprehensive audiometry, Tinnitus Handicap Inventory (THI) scores, and Activities-Specific Balance Confidence Scale (ABC). Tumor control defined as 2 mm linear growth or lower or less than 20% increase in tumor volume (TV), measured in cubic centimeter, after a minimum of 12 months of monitoring, audiogram profiles, THI, and ABC surveys. Of those treated with CK as primary modality, 83% had 0- to 2-mm growth (tumor control or stable) and 17% grew greater than 2 mm. Of the tumors that were stable, 29% shrank 2 mm or greater. Volumetric analysis found that 74% of tumors had less than 20% TV growth, whereas 26% exhibited 20% or greater increase in TV. Of those deemed stable, 65% shrank 20% or greater TV; 95% of patients did not need additional surgical intervention, 3 required salvage surgery and 1 underwent additional radiosurgery. The majority of patients started with Class D hearing, but of those with Class A or B hearing before treatment, 53.5% maintained serviceable hearing at 3 years of follow-up. The pretreatment and posttreatment median THI Grades were both 1. The pretreatment and posttreatment ABC scores were unchanged at 81%. The LINAC-based CK (18 Gy over 3 fractions at 80% isodose line) provides tumor control rates comparable to other forms of radiosurgery. Analysis for tumor growth was positive for 17% using maximum linear diameters and 26% with a volumetric workstation. This discrepancy is consistent with previous reports where

  19. [Radiotherapy of skin cancers].

    PubMed

    Hennequin, C; Rio, E; Mahé, M-A

    2016-09-01

    The indications of radiotherapy for skin cancers are not clearly defined because of the lack of randomised trials or prospective studies. For basal cell carcinomas, radiotherapy frequently offers a good local control, but a randomized trial showed that surgery is more efficient and less toxic. Indications of radiotherapy are contra-indications of surgery for patients older than 60, non-sclerodermiform histology and occurring in non-sensitive areas. Adjuvant radiotherapy could be proposed to squamous cell carcinomas, in case of poor prognostic factors. Dose of 60 to 70Gy are usually required, and must be modulated to the size of the lesions. Adjuvant radiotherapy seems beneficial for desmoplastic melanomas but not for the other histological types. Prophylactic nodal irradiation (45 to 50Gy), for locally advanced tumours (massive nodal involvement), decreases the locoregional failure rate but do not increase survival. Adjuvant radiotherapy (50 to 56Gy) for Merckel cell carcinomas increases also the local control rate, as demonstrated by meta-analysis and a large epidemiological study. Nodal areas must be included, if there is no surgical exploration (sentinel lymph node dissection). Kaposi sarcomas are radiosensitive and could be treated with relatively low doses (24 to 30Gy). Also, cutaneous lymphomas are good indications for radiotherapy: B lymphomas are electively treated with limited fields. The role of total skin electron therapy for T-lymphomas is still discussed; but palliative radiotherapy is very efficient in case of cutaneous nodules.

  20. A new strategy of CyberKnife treatment system based radiosurgery followed by early use of adjuvant bevacizumab treatment for brain metastasis with extensive cerebral edema.

    PubMed

    Wang, Yang; Wang, Enmin; Pan, Li; Dai, Jiazhong; Zhang, Nan; Wang, Xin; Liu, Xiaoxia; Mei, Guanghai; Sheng, Xiaofang

    2014-09-01

    Bevacizumab blocks the effects of vascular endothelial growth factor in leakage-prone capillaries and has been suggested as a new treatment for cerebral radiation edema and necrosis. CyberKnife is a new, frameless stereotactic radiosurgery system. This work investigated the safety and efficacy of CyberKnife followed by early bevacizumab treatment for brain metastasis with extensive cerebral edema. The eligibility criteria of the patients selected for radiosurgery followed by early use of adjuvant bevacizumab treatment were: (1) brain tumors from metastasis with one solitary brain lesion and symptomatic extensive cerebral edema; (2) >18 years of age; (3) the patient refused surgery due to the physical conditions and the risk of surgery; (4) no contraindications for bevacizumab. (5) bevacizumab was applied for a minimum of 2 injections and a maximum of 6 injections with a 2-week interval between treatments, beginning within 2 weeks of the CyberKnife therapy; (6) Karnofsky performance status (KPS) ≥30. Tumor size and edema were monitored by magnetic resonance imaging (MRI). Dexamethasone dosage, KPS, adverse event occurrence and associated clinical outcomes were also recorded. Eight patients were accrued for this new treatment. Radiation dose ranged from 20 to 33 Gy in one to five sessions, prescribed to the 61-71 % isodose line. Bevacizumab therapy was administered 3-10 days after completion of CyberKnife treatment for a minimum of two cycles (5 mg/kg, at 2-week intervals). MRI revealed average reductions of 55.8 % (post-gadolinium) and 63.4 % (T2/FLAIR). Seven patients showed significant clinical neurological improvements. Dexamethasone was reduced in all patients, with five successfully discontinuing dexamethasone treatment 4 weeks after bevacizumab initiation. Hypertension, a bevacizumab-related adverse event, occurred in one patient. After 3-8 months, all patients studied were alive and primary brain metastases were under control, 2 developed new brain

  1. Participating in an International Stereotactic Radiotherapy Patient Registry: The Establishment of Data Collection Pathways.

    PubMed

    Yahya, Aylin; Arneric, Eva; Kernutt, Elizabeth; Baldacchino, Fiona; Haworth, Claire; Kedda, Mary-Anne; Tang, Colin; Bydder, Sean; Corica, Tammy

    2017-06-29

    Aim To describe data collection pathways and practical challenges experienced by an academic comprehensive cancer centre aiming to record clinical data for patients being treated with a novel radiotherapy treatment modality. Methods Various options to capture data from all patients treated with the CyberKnife Robotic Radiosurgery System at Sir Charles Gairdner Hospital (SCGH) in Western Australia were explored. An international multicenter web-based secure database established and maintained by the Radiosurgery Society the RSSearch® Patient Registry was selected. Data were collected and entered over four contiguous phases, with either opt-in or opt-out consent and the completion of Patient Reported Outcome questionnaires for specific sub-groups. Results Between April 2014 and June 2016, 461 patients at Sir Charles Gairdner Hospital were enrolled in the RSSearch® Patient Registry with the collection of over 17,500 data items. From 461 patients enrolled, 447 patients were treated with the CyberKnife Robotic Radiosurgery System. The majority of patients were treated for either a malignant primary (43.2%) or metastatic disease (39.4%). The establishment of matrix organisational processes for data collection led to the development of improved workflow patterns and data collection pathways. Conclusions This article describes the processes developed by a single centre to establish an efficient system for data collection and participation in an international registry. The opt-out approach was more efficient in terms of patient recruitment compared to the informed-consent method used in earlier phases. The experience of this single centre may help inform other institutions considering data collection options for assessments of new or novel treatments.

  2. Investigation of Linac-Based Image-Guided Hypofractionated Prostate Radiotherapy

    SciTech Connect

    Pawlicki, Todd . E-mail: tpaw@stanford.edu; Kim, Gwe-Ya; Hsu, Annie; Cotrutz, Cristian; Boyer, Arthur L.; Xing Lei; King, Christopher R.; Luxton, Gary

    2007-07-01

    A hypofractionation treatment protocol for prostate cancer was initiated in our department in December 2003. The treatment regimen consists of a total dose of 36.25 Gy delivered at 7.25 Gy per fraction over 10 days. We discuss the rationale for such a prostate hypofractionation protocol and the need for frequent prostate imaging during treatment. The CyberKnife (Accuray Inc., Sunnyvale, CA), a linear accelerator mounted on a robotic arm, is currently being used as the radiation delivery device for this protocol, due to its incorporation of near real-time kV imaging of the prostate via 3 gold fiducial seeds. Recently introduced conventional linac kV imaging with intensity modulated planning and delivery may add a new option for these hypofractionated treatments. The purpose of this work is to investigate the use of intensity modulated radiotherapy (IMRT) and the Varian Trilogy Accelerator with on-board kV imaging (Varian Medical Systems Inc., Palo Alto, CA) for treatment of our hypofractionated prostate patients. The dose-volume histograms and dose statistics of 2 patients previously treated on the CyberKnife were compared to 7-field IMRT plans. A process of acquiring images to observe intrafraction prostate motion was achieved in an average time of about 1 minute and 40 seconds, and IMRT beam delivery takes about 40 seconds per field. A complete 7-field IMRT plan can therefore be imaged and delivered in 10 to 17 minutes. The Varian Trilogy Accelerator with on-board imaging and IMRT is well suited for image-guided hypofractionated prostate treatments. During this study, we have also uncovered opportunities for improvement of the on-board imaging hardware/software implementation that would further enhance performance in this regard.

  3. [Prostate cancer external beam radiotherapy].

    PubMed

    de Crevoisier, R; Pommier, P; Latorzeff, I; Chapet, O; Chauvet, B; Hennequin, C

    2016-09-01

    The prostate external beam radiotherapy techniques are described, when irradiating the prostate or after prostatectomy, with and without pelvic lymph nodes. The following parts are presented: indications of radiotherapy, total dose and fractionation, planning CT image acquisition, volume of interest delineation (target volumes and organs at risk) and margins, Intensity modulated radiotherapy planning and corresponding dose-volume constraints, and finally Image guided radiotherapy.

  4. 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.

  5. Split-volume treatment planning of multiple consecutive vertebral body metastases for cyberknife image-guided robotic radiosurgery.

    PubMed

    Sahgal, Arjun; Chuang, Cynthia; Larson, David; Huang, Kim; Petti, Paula; Weinstein, Phil; Ma, Lijun

    2008-01-01

    Cyberknife treatment planning of multiple consecutive vertebral body metastases is challenging due to large target volumes adjacent to critical normal tissues. A split-volume treatment planning technique was developed to improve the treatment plan quality of such lesions. Treatment plans were generated for 1 to 5 consecutive thoracic vertebral bodies (CVBM) prescribing a total dose of 24 Gy in 3 fractions. The planning target volume (PTV) consisted of the entire vertebral body(ies). Treatment plans were generated considering both the de novo clinical scenario (no prior radiation), imposing a dose limit of 8 Gy to 1 cc of spinal cord, and the retreatment scenario (prior radiation) with a dose limit of 3 Gy to 1 cc of spinal cord. The split-volume planning technique was compared with the standard full-volume technique only for targets ranging from 2 to 5 CVBM in length. The primary endpoint was to obtain best PTV coverage by the 24 Gy prescription isodose line. A total of 18 treatment plans were generated (10 standard and 8 split-volume). PTV coverage by the 24-Gy isodose line worsened consistently as the number of CVBM increased for both the de novo and retreatment scenario. Split-volume planning was achieved by introducing a 0.5-cm gap, splitting the standard full-volume PTV into 2 equal length PTVs. In every case, split-volume planning resulted in improved PTV coverage by the 24-Gy isodose line ranging from 4% to 12% for the de novo scenario and, 8% to 17% for the retreatment scenario. We did not observe a significant trend for increased monitor units required, or higher doses to spinal cord or esophagus, with split-volume planning. Split-volume treatment planning significantly improves Cyberknife treatment plan quality for CVBM, as compared to the standard technique. This technique may be of particular importance in clinical situations where stringent spinal cord dose limits are required.

  6. SU-E-J-64: Feasibility Study of Surgical Clips for Fiducial Tracking in CyberKnife System

    SciTech Connect

    Lee, H; Yoon, J; Lee, E; Cho, S; Park, K; Choi, W; Baek, J; Keum, K; Koom, W

    2015-06-15

    Purpose: To investigate the ability of CyberKnife to track surgical clips used as fiducial markers. Methods: The Octavius 1000SRS detector and solid water (RW3) slab phantom were used with motion platform to evaluate the study. The RW3 slab phantom was set up to measure the dose distribution from coronal plane. It consists of 9 plates and the thickness of each plate is 10mm. Among them, one plate was attached with 3 surgical clips, which are orthogonally positioned on outer region of array. The length of attached clip was represented as 1cm on planning CT. The clip plate was placed on the 1000SRS detector and 3 slabs were stacked up on the plate to build the measuring depth. Below the detector, 5 slabs were set. The two-axis motion platform was programmed with 1D sinusoidal movement (20mm peak-to-peak, 3s period) toward superior/inferior and left/right directions to simulate target motion. During delivery, two clips were extracted by two X-ray imagers, which led to translational error correction only. Synchrony was also used for dynamic tracking. After the irradiation, the measured dose distribution of coronal plane was compared with the planar dose distribution calculated by the CyberKnife treatment planning system (Multiplan) for cross verification. The results were assessed by comparing the absolute Gamma (γ) index. Results: The dose distributions measured by the 1000SRS detector were in good agreements with those calculated by Multiplan. In the dosimetric comparison using γ-function criteria based on the distance-to-agreement of 3mm and the local dose difference of 3%, the passing rate with γ- parameter ≤1 was 91% in coronal plane. Conclusion: The surgical clips can be considered as new fiducials for robotic radiosurgery delivery by considering the target margin with less than 5mm.

  7. Split-Volume Treatment Planning of Multiple Consecutive Vertebral Body Metastases for Cyberknife Image-Guided Robotic Radiosurgery

    SciTech Connect

    Sahgal, Arjun Chuang, Cynthia; Larson, David; Huang, Kim; Petti, Paula; Weinstein, Phil; Ma Lijun

    2008-10-01

    Cyberknife treatment planning of multiple consecutive vertebral body metastases is challenging due to large target volumes adjacent to critical normal tissues. A split-volume treatment planning technique was developed to improve the treatment plan quality of such lesions. Treatment plans were generated for 1 to 5 consecutive thoracic vertebral bodies (CVBM) prescribing a total dose of 24 Gy in 3 fractions. The planning target volume (PTV) consisted of the entire vertebral body(ies). Treatment plans were generated considering both the de novo clinical scenario (no prior radiation), imposing a dose limit of 8 Gy to 1 cc of spinal cord, and the retreatment scenario (prior radiation) with a dose limit of 3 Gy to 1 cc of spinal cord. The split-volume planning technique was compared with the standard full-volume technique only for targets ranging from 2 to 5 CVBM in length. The primary endpoint was to obtain best PTV coverage by the 24 Gy prescription isodose line. A total of 18 treatment plans were generated (10 standard and 8 split-volume). PTV coverage by the 24-Gy isodose line worsened consistently as the number of CVBM increased for both the de novo and retreatment scenario. Split-volume planning was achieved by introducing a 0.5-cm gap, splitting the standard full-volume PTV into 2 equal length PTVs. In every case, split-volume planning resulted in improved PTV coverage by the 24-Gy isodose line ranging from 4% to 12% for the de novo scenario and, 8% to 17% for the retreatment scenario. We did not observe a significant trend for increased monitor units required, or higher doses to spinal cord or esophagus, with split-volume planning. Split-volume treatment planning significantly improves Cyberknife treatment plan quality for CVBM, as compared to the standard technique. This technique may be of particular importance in clinical situations where stringent spinal cord dose limits are required.

  8. Determination of kQ using MLC-collimated rectangular fields for absolute dosimetry of the CyberKnife.

    PubMed

    Gersh, Jacob A; Willett, Benjamin

    2015-11-01

    Traditional CyberKnife (CK) calibration uses TG-51, which requires kQ to be defined using the standard reference condition of 100 cm SSD in a 10 cm×10 cm field. Since the CK is calibrated using a 6 cm fixed-aperture collimating cone at 80 cm SAD, the BJR-25 method is commonly used to relate circular-field PDDs to square-field PDDs for kQ determination. Using the InCise MLC system, the CK is able to deliver rectangular fields, allowing a more direct measurement of %dd(10 cm) using conventional reference conditions. We define the PDD correction factor (CPDD) as the ratio of %dd(10 cm) measured using CK reference conditions to that measured using standard TG-51 reference conditions. Using four ionization chambers (A1SL, CC08, CC13, and A19), %dd(10 cm) is measured using a 6 cm fixed cone at 80 cm SSD and at 100 cm SSD using an effective 10 cm×10 cm MLC-collimated field. These values are used to calculate CPDD, while the latter is used to directly calculate a kQ value. This direct kQ value is then compared to values determined using the BJR-25 method. Using the MLC system, this study demonstrates conversion between the %dd(10 cm) measured using CyberKnife reference conditions and TG-51 reference conditions. These values provide the means for derivation of a kQ curve as a function of direct measurements of %dd(10 cm) using a 6 cm fixed-aperture collimating cone at 80 cm SSD. PACS number: 87.55.Qr.

  9. Cyberknife Radiosurgery and Concurrent Intrathecal Chemotherapy for Leptomeningeal Metastases: Case Report of Prolonged Survival of a HER-2+ Breast Cancer Patient Status-Post Craniospinal Irradiation.

    PubMed

    Lekovic, Gregory; Drazin, Doniel; Mak, Albert C; Schwartz, Marc S

    2016-01-07

    Leptomeningeal disease (LMD) from breast cancer is usually a rapidly fatal condition, with median overall survival reported to be 15 weeks. Conventional treatment for LMD includes craniospinal irradiation and intrathecal (IT) methotrexate. However, the role of stereotactic radiation for leptomeningeal disease remains poorly defined. This case report describes our experience using Cyberknife radiosurgery to treat a 49-year-old female with HER-2+ breast cancer and focal/nodular leptomeningeal metastases that were refractory to craniospinal irradiation and concurrent IT chemotherapy. This combined approach--i.e., craniospinal irradiation, IT chemotherapy, and Cyberknife Radiosurgery for local, recurrent metastases--resulted in survival of 46 months with controlled disease. Based on our experience with this patient, we believe further consideration of radiosurgery for LMD is warranted.

  10. Cyberknife Radiosurgery and Concurrent Intrathecal Chemotherapy for Leptomeningeal Metastases: Case Report of Prolonged Survival of a HER-2+ Breast Cancer Patient Status-Post Craniospinal Irradiation

    PubMed Central

    Lekovic, Gregory; Mak, Albert C; Schwartz, Marc S

    2016-01-01

    Leptomeningeal disease (LMD) from breast cancer is usually a rapidly fatal condition, with median overall survival reported to be 15 weeks. Conventional treatment for LMD includes craniospinal irradiation and intrathecal (IT) methotrexate. However, the role of stereotactic radiation for leptomeningeal disease remains poorly defined. This case report describes our experience using Cyberknife radiosurgery to treat a 49-year-old female with HER-2+ breast cancer and focal/nodular leptomeningeal metastases that were refractory to craniospinal irradiation and concurrent IT chemotherapy. This combined approach--i.e., craniospinal irradiation, IT chemotherapy, and Cyberknife Radiosurgery for local, recurrent metastases--resulted in survival of 46 months with controlled disease. Based on our experience with this patient, we believe further consideration of radiosurgery for LMD is warranted.  PMID:26918221

  11. Recruitment in Radiotherapy

    ERIC Educational Resources Information Center

    Deeley, T. J.; And Others

    1976-01-01

    The Faculty Board of Radiotherapy and Oncology of the Royal College of Radiobiologists surveyed the factors thought to influence recruitment into the specialty. Possible factors listed in replies of 36 questionnaires are offered. (LBH)

  12. Recruitment in Radiotherapy

    ERIC Educational Resources Information Center

    Deeley, T. J.; And Others

    1976-01-01

    The Faculty Board of Radiotherapy and Oncology of the Royal College of Radiobiologists surveyed the factors thought to influence recruitment into the specialty. Possible factors listed in replies of 36 questionnaires are offered. (LBH)

  13. Planning a Radiotherapy Department.

    PubMed

    van der Merwe, D

    2017-02-01

    The master planning of new radiotherapy facilities requires the input and engagement of a range of highly specialised professionals, both in the construction and health sector. Although radiation protection and safety aspects of radiotherapy services are universal, low and middle income countries are often presented with unique challenges that also need to be considered, e.g. competing needs within the health sector, lack of financial and human resources, environmental factors like poor provision of transport or electrical power, inadequate regulatory infrastructure, etc. Efforts to establish, upgrade or expand radiotherapy services should therefore not only focus on the technology that is appropriate and sustainable, but also be mindful of the need for quality, safety and optimal utilisation of technology. The workflow in a radiotherapy department can be facilitated by strategic placement of the main functional areas into the concept design. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  14. SU-E-T-281: Reduction of Treatment Times in CyberKnife Prostate SBRT Using a Water Filled Rectal Balloon

    SciTech Connect

    Desai, P; Caroprese, B; McKellar, H

    2014-06-01

    Purpose: To illustrate 25% reduction in CyberKnife prostate SBRT treatment times using a water filled rectal balloon. Methods: We perform prostate SBRT using a 3800cGy in 4 fraction regimen prescribed between 51% 59% iso-dose lines to 95% of PTV using a CyberKnife System. The resultant heterogeneous dosimetry is analogous to HDR dosimetry. Our patients are treated in a feet first supine position to decrease treatment couch sag and also to position the prostate anatomy closer to the robot. CT imaging is performed with a Radiadyne Immobiloc rectal balloon filled with 45-50cc water placed firmly inside the patient's rectum. A treatment plan is developed from this CT study using Multiplan. The patient is treated every other day for 4 days using the rectal balloon for each fraction. Gold fiducials previously implanted inside the prostate are used for tracking by the CyberKnife system. Results: Critical structures comprise the usual GU anatomy of bladder, rectum, urethra, femoral-heads along with emphasis on doses to anterior rectal wall and rectal mucosa. The water filled rectal balloon localizes the rectum, which enables the physician to accurately contour both anterior rectal wall, and rectal mucosa. The balloon also has a gas release valve enabling better patient comfort. Rectum localization enables the CyberKnife system to make fewer corrections resulting in fewer treatment interruptions and time lost to re-adjustment for rectal motion, bowel filling and gas creation. Effective treatment times are reduced by 25% to approximately 45 minutes. Adoption of the balloon has required minimal change to our planning strategy and plan evaluation process. Conclusion: Patient follow-up comparisons show no difference in effectiveness of treatment with and without balloons We conclude that rectal balloons enhance patient comfort and decrease effective treatment times.

  15. Sci—Sat AM: Stereo — 09: Accuracy of Liver Cancer Treatment on Cyberknife® with Synchrony™ Optical Tracking Throughout the Respiratory Cycle

    SciTech Connect

    Winter, J.; Chow, T; Wong, R.

    2014-08-15

    The Cyberknife® robotic stereotactic body radiation therapy system is well-suited for treating liver lesions over the respiratory cycle as it includes room-mounted orthogonal x-ray tracking of internal fiducial markers and optical tracking of external markers. The Synchrony™ software generates a model of internal target positions during patient respiration and correlates it to the external optical tracking system for real-time optical-based position corrections of the linear accelerator during beam delivery. Although clinical studies have provided preliminary outcomes for liver lesions treated with the Cyberknife system, to date, there is little data demonstrating the ability of the Synchrony software to track targets in the liver, which deforms throughout the respiratory cycle. In this study, we investigated the respiratory motion model performance for predicting tumour motion. We conducted a retrospective analysis of fifteen liver cancer patients treated on the Cyberknife using the Synchrony optical tracking system. We analyzed Cyberknife tracking information stored in the log files to extract the left-right (LR), anterior-posterior (AP) and superior-inferior (SI) correlation errors between the model-predicted position and the internal fiducial centroid position determined by x-ray imaging. Only translational tracking and corrections were applied during treatment. Overall, the correlation errors were greatest in the SI direction. We calculated radial correlation errors, and determined that the 95{sup th}, 98{sup th} and 99{sup th} percentile errors were 3.4 mm, 4.4 mm and 5.1 mm, respectively. Based on translational correlation tracking errors we expect the clinical target volume will be within 3.4 mm of the planning target volume for 95 % of beam delivery time.

  16. Dosimetric comparison of Linac-based (BrainLAB®) and robotic radiosurgery (CyberKnife ®) stereotactic system plans for acoustic schwannoma.

    PubMed

    Dutta, Debnarayan; Balaji Subramanian, S; Murli, V; Sudahar, H; Gopalakrishna Kurup, P G; Potharaju, Mahadev

    2012-02-01

    A dosimetric comparison of linear accelerator (LA)-based (BrainLAB) and robotic radiosurgery (RS) (CyberKnife) systems for acoustic schwannoma (Acoustic neuroma, AN) was carried out. Seven patients with radiologically confirmed unilateral AN were planned with both an LA-based (BrainLAB) and robotic RS (CyberKnife) system using the same computed tomography (CT) dataset and contours. Gross tumour volume (GTV) was contoured on post-contrast magnetic resonance imaging (MRI) scan [planning target volume (PTV) margin 2 mm]. Planning and calculation were done with appropriate calculation algorithms. The prescribed isodose in both systems was considered adequate to cover at least 95% of the contoured target. Plan evaluations were done by examining the target coverage by the prescribed isodose line, and high- and low-dose volumes. Isodose plans and dose volume histograms generated by the two systems were compared. There was no statistically significant difference between the contoured volumes between the systems. Tumour volumes ranged from 380 to 3,100 mm(3). Dose prescription was 13-15 Gy in single fraction (median prescribed isodose 85%). There were no significant differences in conformity index (CI) (0.53 versus 0.58; P = 0.225), maximum brainstem dose (4.9 versus 4.7 Gy; P = 0.935), 2.5-Gy volume (39.9 versus 52.3 cc; P = 0.238) or 5-Gy volume (11.8 versus 16.8 cc; P = 0.129) between BrainLAB and CyberKnife system plans. There were statistically significant differences in organs at risk (OAR) doses, such as mean cochlear dose (6.9 versus 5.4 Gy; P = 0.001), mean mesial temporal dose (2.6 versus 1.7 Gy; P = 0.07) and high-dose (10 Gy) volume (3.2 versus 5.2 cc; P = 0.017). AN patients planned with the CyberKnife system had superior OAR (cochlea and mesial temporal lobe) sparing compared with those planned with the Linac-based system. Further evaluation of these findings in prospective studies with clinical correlation will provide actual clinical benefit from the

  17. [Radiotherapy of larynx cancers].

    PubMed

    Pointreau, Y; Lafond, C; Legouté, F; Trémolières, P; Servagi-Vernat, S; Giraud, P; Maingon, P; Calais, G; Lapeyre, M

    2016-09-01

    Intensity-modulated radiotherapy is the gold standard in the treatment of larynx cancers (except T1 glottic tumour). Early T1 and T2 tumours may be treated by exclusive radiation or surgery. For tumours requiring total laryngectomy (T2 or T3), induction chemotherapy followed by exclusive radiotherapy or concurrent chemoradiotherapy is possible. For T4 tumour, surgery must be proposed. The treatment of lymph nodes is based on the initial treatment of the primary tumour. In non-surgical procedure, in case of sequential radiotherapy, the curative dose is 70Gy and the prophylactic dose is 50Gy. An integrated simultaneous boost radiotherapy is allowed (70Gy in 2Gy per fraction and 56Gy in 1.8Gy per fraction or 70Gy in 2.12Gy per fraction). Postoperatively, radiotherapy is used in locally advanced cancer with dose levels based on pathologic criteria (66Gy for R1 resection, 50 to 54Gy for complete resection). Volume delineation was based on guidelines.

  18. Verification of Accuracy of CyberKnife Tumor-tracking Radiation Therapy Using Patient-specific Lung Phantoms

    SciTech Connect

    Jung, Jinhong; Song, Si Yeol; Yoon, Sang Min; Kwak, Jungwon; Yoon, KyoungJun; Choi, Wonsik; Jeong, Seong-Yun; Choi, Eun Kyung; Cho, Byungchul

    2015-07-15

    Purpose: To investigate the accuracy of the CyberKnife Xsight Lung Tracking System (XLTS) compared with that of a fiducial-based target tracking system (FTTS) using patient-specific lung phantoms. Methods and Materials: Three-dimensional printing technology was used to make individualized lung phantoms that closely mimicked the lung anatomy of actual patients. Based on planning computed tomographic data from 6 lung cancer patients who underwent stereotactic ablative radiation therapy using the CyberKnife, the volume above a certain Hounsfield unit (HU) was assigned as the structure to be filled uniformly with polylactic acid material by a 3-dimensional printer (3D Edison, Lokit, Korea). We evaluated the discrepancies between the measured and modeled target positions, representing the total tracking error, using 3 log files that were generated during each treatment for both the FTTS and the XLTS. We also analyzed the γ index between the film dose measured under the FTTS and XLTS. Results: The overall mean values and standard deviations of total tracking errors for the FTTS were 0.36 ± 0.39 mm, 0.15 ± 0.64 mm, and 0.15 ± 0.62 mm for the craniocaudal (CC), left–right (LR), and anteroposterior (AP) components, respectively. Those for the XLTS were 0.38 ± 0.54 mm, 0.13 ± 0.18 mm, and 0.14 ± 0.37 mm for the CC, LR, and AP components, respectively. The average of γ passing rates was 100% for the criteria of 3%, 3 mm; 99.6% for the criteria of 2%, 2 mm; and 86.8% for the criteria of 1%, 1 mm. Conclusions: The XLTS has segmentation accuracy comparable with that of the FTTS and small total tracking errors.

  19. SU-E-T-252: Developing a Pencil Beam Dose Calculation Algorithm for CyberKnife System

    SciTech Connect

    Liang, B; Liu, B; Zhou, F; Xu, S; Wu, Q

    2015-06-15

    Purpose: Currently there are two dose calculation algorithms available in the Cyberknife planning system: ray-tracing and Monte Carlo, which is either not accurate or time-consuming for irregular field shaped by the MLC that was recently introduced. The purpose of this study is to develop a fast and accurate pencil beam dose calculation algorithm which can handle irregular field. Methods: A pencil beam dose calculation algorithm widely used in Linac system is modified. The algorithm models both primary (short range) and scatter (long range) components with a single input parameter: TPR{sub 20}/{sub 10}. The TPR{sub 20}/{sub 20}/{sub 10} value was first estimated to derive an initial set of pencil beam model parameters (PBMP). The agreement between predicted and measured TPRs for all cones were evaluated using the root mean square of the difference (RMSTPR), which was then minimized by adjusting PBMPs. PBMPs are further tuned to minimize OCR RMS (RMSocr) by focusing at the outfield region. Finally, an arbitrary intensity profile is optimized by minimizing RMSocr difference at infield region. To test model validity, the PBMPs were obtained by fitting to only a subset of cones (4) and applied to all cones (12) for evaluation. Results: With RMS values normalized to the dmax and all cones combined, the average RMSTPR at build-up and descending region is 2.3% and 0.4%, respectively. The RMSocr at infield, penumbra and outfield region is 1.5%, 7.8% and 0.6%, respectively. Average DTA in penumbra region is 0.5mm. There is no trend found in TPR or OCR agreement among cones or depths. Conclusion: We have developed a pencil beam algorithm for Cyberknife system. The prediction agrees well with commissioning data. Only a subset of measurements is needed to derive the model. Further improvements are needed for TPR buildup region and OCR penumbra. Experimental validations on MLC shaped irregular field needs to be performed. This work was partially supported by the National

  20. Correction factors for ionization chamber dosimetry in CyberKnife: Machine-specific, plan-class, and clinical fields

    SciTech Connect

    Gago-Arias, Araceli; Antolin, Elena; Fayos-Ferrer, Francisco; Simon, Rocio; Gonzalez-Castano, Diego M.; Palmans, Hugo; Sharpe, Peter; Gomez, Faustino; Pardo-Montero, Juan

    2013-01-15

    Purpose: The aim of this work is the application of the formalism for ionization chamber reference dosimetry of small and nonstandard fields [R. Alfonso, P. Andreo, R. Capote, M. S. Huq, W. Kilby, P. Kjaell, T. R. Mackie, H. Palmans, K. Rosser, J. Seuntjens, W. Ullrich, and S. Vatnitsky, 'A new formalism for reference dosimetry of small and nonstandard fields,' Med. Phys. 35, 5179-5186 (2008)] to the CyberKnife robotic radiosurgery system. Correction factors for intermediate calibration fields, a machine-specific reference field (msr) and two plan-class specific reference fields (pcsr), have been studied. Furthermore, the applicability of the new formalism to clinical dosimetry has been analyzed through the investigation of two clinical treatments. Methods: PTW31014 and Scanditronix-Wellhofer CC13 ionization chamber measurements were performed for the fields under investigation. Absorbed dose to water was determined using alanine reference dosimetry, and experimental correction factors were calculated from alanine to ionization chamber readings ratios. In addition, correction factors were calculated for the intermediate calibration fields and one of the clinical treatment fields using the Monte Carlo method and these were compared with the experimental values. Results: Overall correction factors deviating from unity by approximately 2% were obtained from both measurements and simulations, with values below and above unity for the studied intermediate calibration fields and clinical fields for the ionization chambers under consideration. Monte Carlo simulations yielded correction factors comparable with those obtained from measurements for the machine-specific reference field, although differences from 1% to 3.3% were observed between measured and calculated correction factors for the composite intermediate calibration fields. Dose distribution inhomogeneities are thought to be responsible for such discrepancies. Conclusions: The differences found between overall

  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. [Radiotherapy for retroperitoneal sarcomas].

    PubMed

    Sargos, P; Stoeckle, E; Henriques de Figueiredo, B; Antoine, M; Delannes, M; Mervoyer, A; Kantor, G

    2016-10-01

    The management of retroperitoneal sarcoma can be very challenging, and the quality of initial treatment strategy appears to be a crucial prognostic factor. En bloc surgery is currently the standard of care for these rare tumours and perioperative treatments such as chemotherapy or radiotherapy have not been validated yet. However, local-regional relapse constitutes the most common disease course. While adjuvant radiotherapy is less and less common due to gastrointestinal toxicities, preoperative radiation therapy offers numerous advantages and is being evaluated as part of a national multicentre phase II study (TOMOREP trial) and is the subject of a European randomized phase III study (STRASS trial). The objective of this article is to present data on preoperative irradiation in terms of dose, volumes and optimal radiotherapy techniques for the treatment of this rare disease.

  3. Radiotherapy for lung cancer

    SciTech Connect

    Bleehen, N.M.; Cox, J.D.

    1985-05-01

    The role of radiation therapy in the management of lung cancer was reviewed at a workshop held in Cambridge, England, in June 1984. It was concluded that there was a continuing role for radiation therapy in the primary management of small cell lung cancer, including the loco-regional treatment for patients with limited disease. Radical radiotherapy for patients with non-small cell carcinoma could be curative for a proportion of patients with limited disease. Careful planning and quality control was essential. Palliative radiotherapy provided useful treatment for many other patients. Other related aspects of treatment are also presented.

  4. Continuous versus step-by-step scanning mode of a novel 3D scanner for CyberKnife measurements.

    PubMed

    Al Kafi, M Abdullah; Mwidu, Umar; Moftah, Belal

    2015-11-01

    The purpose of the study is to investigate the continuous versus step-by-step scanning mode of a commercial circular 3D scanner for commissioning measurements of a robotic stereotactic radiosurgery system. The 3D scanner was used for profile measurements in step-by-step and continuous modes with the intent of comparing the two scanning modes for consistency. The profile measurements of in-plane, cross-plane, 15 degree, and 105 degree were performed for both fixed cones and Iris collimators at depth of maximum dose and at 10cm depth. For CyberKnife field size, penumbra, flatness and symmetry analysis, it was observed that the measurements with continuous mode, which can be up to 6 times faster than step-by-step mode, are comparable and produce scans nearly identical to step-by-step mode. When compared with centered step-by-step mode data, a fully processed continuous mode data gives rise to maximum of 0.50% and 0.60% symmetry and flatness difference respectfully for all the fixed cones and Iris collimators studied.

  5. SU-E-T-85: Comparison of Treatment Plans Calculated Using Ray Tracing and Monte Carlo Algorithms for Lung Cancer Patients Having Undergone Radiotherapy with Cyberknife

    SciTech Connect

    Pennington, A; Selvaraj, R; Kirkpatrick, S; Oliveira, S; Leventouri, T

    2014-06-01

    Purpose: The latest publications indicate that the Ray Tracing algorithm significantly overestimates the dose delivered as compared to the Monte Carlo (MC) algorithm. The purpose of this study is to quantify this overestimation and to identify significant correlations between the RT and MC calculated dose distributions. Methods: Preliminary results are based on 50 preexisting RT algorithm dose optimization and calculation treatment plans prepared on the Multiplan treatment planning system (Accuray Inc., Sunnyvale, CA). The analysis will be expanded to include 100 plans. These plans are recalculated using the MC algorithm, with high resolution and 1% uncertainty. The geometry and number of beams for a given plan, as well as the number of monitor units, is constant for the calculations for both algorithms and normalized differences are compared. Results: MC calculated doses were significantly smaller than RT doses. The D95 of the PTV was 27% lower for the MC calculation. The GTV and PTV mean coverage were 13 and 39% less for MC calculation. The first parameter of conformality, as defined as the ratio of the Prescription Isodose Volume to the PTV Volume was on average 1.18 for RT and 0.62 for MC. Maximum doses delivered to OARs was reduced in the MC plans. The doses for 1000 and 1500 cc of total lung minus PTV, respectively were reduced by 39% and 53% for the MC plans. The correlation of the ratio of air in PTV to the PTV with the difference in PTV coverage had a coefficient of −0.54. Conclusion: The preliminary results confirm that the RT algorithm significantly overestimates the dosages delivered confirming previous analyses. Finally, subdividing the data into different size regimes increased the correlation for the smaller size PTVs indicating the MC algorithm improvement verses the RT algorithm is dependent upon the size of the PTV.

  6. Innovations in Radiotherapy Technology.

    PubMed

    Feain, I J; Court, L; Palta, J R; Beddar, S; Keall, P

    2017-02-01

    Many low- and middle-income countries, together with remote and low socioeconomic populations within high-income countries, lack the resources and services to deal with cancer. The challenges in upgrading or introducing the necessary services are enormous, from screening and diagnosis to radiotherapy planning/treatment and quality assurance. There are severe shortages not only in equipment, but also in the capacity to train, recruit and retain staff as well as in their ongoing professional development via effective international peer-review and collaboration. Here we describe some examples of emerging technology innovations based on real-time software and cloud-based capabilities that have the potential to redress some of these areas. These include: (i) automatic treatment planning to reduce physics staffing shortages, (ii) real-time image-guided adaptive radiotherapy technologies, (iii) fixed-beam radiotherapy treatment units that use patient (rather than gantry) rotation to reduce infrastructure costs and staff-to-patient ratios, (iv) cloud-based infrastructure programmes to facilitate international collaboration and quality assurance and (v) high dose rate mobile cobalt brachytherapy techniques for intraoperative radiotherapy. Copyright © 2016 The Royal College of Radiologists. All rights reserved.

  7. Precision radiotherapy for brain tumors

    PubMed Central

    Yan, Ying; Guo, Zhanwen; Zhang, Haibo; Wang, Ning; Xu, Ying

    2012-01-01

    OBJECTIVE: Precision radiotherapy plays an important role in the management of brain tumors. This study aimed to identify global research trends in precision radiotherapy for brain tumors using a bibliometric analysis of the Web of Science. DATA RETRIEVAL: We performed a bibliometric analysis of data retrievals for precision radiotherapy for brain tumors containing the key words cerebral tumor, brain tumor, intensity-modulated radiotherapy, stereotactic body radiation therapy, stereotactic ablative radiotherapy, imaging-guided radiotherapy, dose-guided radiotherapy, stereotactic brachytherapy, and stereotactic radiotherapy using the Web of Science. SELECTION CRITERIA: Inclusion criteria: (a) peer-reviewed articles on precision radiotherapy for brain tumors which were published and indexed in the Web of Science; (b) type of articles: original research articles and reviews; (c) year of publication: 2002-2011. Exclusion criteria: (a) articles that required manual searching or telephone access; (b) Corrected papers or book chapters. MAIN OUTCOME MEASURES: (1) Annual publication output; (2) distribution according to country; (3) distribution according to institution; (4) top cited publications; (5) distribution according to journals; and (6) comparison of study results on precision radiotherapy for brain tumors. RESULTS: The stereotactic radiotherapy, intensity-modulated radiotherapy, and imaging-guided radiotherapy are three major methods of precision radiotherapy for brain tumors. There were 260 research articles addressing precision radiotherapy for brain tumors found within the Web of Science. The USA published the most papers on precision radiotherapy for brain tumors, followed by Germany and France. European Synchrotron Radiation Facility, German Cancer Research Center and Heidelberg University were the most prolific research institutes for publications on precision radiotherapy for brain tumors. Among the top 13 research institutes publishing in this field, seven

  8. A Retrospective Comparison of Robotic Stereotactic Body Radiotherapy and Three-Dimensional Conformal Radiotherapy for the Reirradiation of Locally Recurrent Nasopharyngeal Carcinoma

    SciTech Connect

    Ozyigit, Gokhan; Cengiz, Mustafa; Yazici, Gozde; Yildiz, Ferah; Gurkaynak, Murat; Zorlu, Faruk; Yildiz, Demet; Hosal, Sefik; Gullu, Ibrahim; Akyol, Fadil

    2011-11-15

    Purpose: We assessed therapeutic outcomes of reirradiation with robotic stereotactic radiotherapy (SBRT) for locally recurrent nasopharyngeal carcinoma (LRNPC) patients and compared those results with three-dimensional conformal radiotherapy (CRT) with or without brachytherapy (BRT). Methods and Materials: Treatment outcomes were evaluated retrospectively in 51 LRNPC patients receiving either robotic SBRT (24 patients) or CRT with or without BRT (27 patients) in our department. CRT was delivered with a 6-MV linear accelerator, and a median total reirradiation dose of 57 Gy in 2 Gy/day was given. Robotic SBRT was delivered with CyberKnife (Accuray, Sunnyvale, CA). Patients in the SBRT arm received 30 Gy over 5 consecutive days. We calculated actuarial local control and cancer-specific survival rates for the comparison of treatment outcomes in SBRT and CRT arms. The Common Terminology Criteria for Adverse Events v3.0 was used for toxicity evaluation. Results: The median follow-up was 24 months for all patients. Two-year actuarial local control rates were 82% and 80% for SBRT and CRT arms, respectively (p = 0.6). Two-year cancer-specific survival rates were 64% and 47% for the SBRT and CRT arms, respectively (p = 0.4). Serious late toxicities (Grade 3 and above) were observed in 21% of patients in the SBRT arm, whereas 48% of patients had serious toxicity in the CRT arm (p = 0.04). Fatal complications occurred in three patients (12.5%) of the SBRT arm, and four patients (14.8%) of the CRT arm (p = 0.8). T stage at recurrence was the only independent predictor for local control and survival. Conclusion: Our robotic SBRT protocol seems to be feasible and less toxic in terms of late effects compared with CRT arm for the reirradiation of LRNPC patients.

  9. SU-E-T-642: Safety Procedures for Error Elimination in Cyberknife Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT)

    SciTech Connect

    Hussain, A; Alkafi, A; Al-Najjar, W; Moftah, B

    2014-06-15

    Purpose: Cyberknife system is used for providing stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) hypofractionation scheme. The whole treatment delivery is based on live imaging of the patient. The minor error made at any stage may bring severe radiation injury to the patient or damage to the system itself. Several safety measures were taken to make the system safer. Methods: The radiation treatment provided thru a 6MV linac attached to Kuka robot (Cyberknife G4, Accuray Inc. Sunnyvale, CA, USA). Several possible errors were identified related to patient alignment, treatment planning, dose delivery and physics quality assurance. During dose delivery, manual and visual checks were introduced to confirm pre and intra-treatment imaging to reduce possible errors. One additional step was introduced to confirm that software tracking-tools had worked correctly with highest possible confidence level. Robotic head move in different orientations over and around the patient body, the rigidity of linac-head cover and other accessories was checked periodically. The vender was alerted when a tiny or bigger piece of equipment needed additional interlocked support. Results: As of our experience treating 525 patients on Cyberknife during the last four years, we saw on and off technical issues. During image acquisition, it was made essential to follow the site-specific imaging protocols. Adequate anatomy was contoured to document the respective doses. Followed by auto-segmentation, manual tweaking was performed on every structure. The calculation box was enclosing the whole image during the final calculation. Every plan was evaluated on slice-by slice basis. To review the whole process, a check list was maintained during the physics 2nd-check. Conclusion: The implementation of manual and visual additional checks introduced along with automated checks for confirmation was found promising in terms of reduction in systematic errors and making the system

  10. Integration of fMRI and MEG functional maps into a CyberKnife planning system: feasibility study for motor activity localization and dose planning.

    PubMed

    De Martin, Elena; Duran, Dunja; Ghielmetti, Francesco; Visani, Elisa; Aquino, Domenico; Marchetti, Marcello; Rossi Sebastiano, Davide; Cusumano, Davide; Bruzzone, Maria Grazia; Panzica, Ferruccio; Fariselli, Laura

    2017-09-20

    Magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) provide non-invasive localization of eloquent brain areas for pre-surgical planning. The aim of this study is the integration of MEG and fMRI maps into a CyberKnife (CK) system to optimize dose planning. Four patients with brain metastases in the motor area underwent functional imaging study of the hand motor cortex prior radiosurgery. MEG data were acquired during a visually cued hand motor-task. Motor activations were identified also using an fMRI block-designed paradigm. MEG and fMRI maps were then integrated into a CK system and contoured as organs at risk (OARs) for treatment planning optimization. The integration of fMRI data into the CK system was achieved for all patients by means of a standardized protocol. We also implemented an ad hoc pipeline to convert the MEG signal into DICOM standard, to make sure that it was readable by our CyberKnife treatment planning system. Inclusion of the activation areas into the optimization plan allowed the creation of treatment plans which reduced the irradiation of the motor cortex while not affecting the brain peripheral dose. The availability of advanced neuroimaging techniques is playing a more and more important role in radiosurgical planning strategy. We successfully imported MEG and fMRI activations into a CyberKnife system. This additional information can improve dose sparing of eloquent areas, allowing a more comprehensive investigation of the related dose-volume constraints which in theory could translate into a gain in tumor local control and reduction of neurological complications. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. SU-F-SPS-11: The Dosimetric Comparison of Truebeam 2.0 and Cyberknife M6 Treatment Plans for Brain SRS Treatment

    SciTech Connect

    Mabhouti, H; Sanli, E; Cebe, M; Codel, G; Pacaci, P; Serin, E; Kucuk, N; Kucukmorkoc, E; Doyuran, M; Canoglu, D; Altinok, A; Acar, H; Caglar Ozkok, H

    2016-06-15

    Purpose: Brain stereotactic radiosurgery involves the use of precisely directed, single session radiation to create a desired radiobiologic response within the brain target with acceptable minimal effects on surrounding structures or tissues. In this study, the dosimetric comparison of Truebeam 2.0 and Cyberknife M6 treatment plans were made. Methods: For Truebeam 2.0 machine, treatment planning were done using 2 full arc VMAT technique with 6 FFF beam on the CT scan of Randophantom simulating the treatment of sterotactic treatments for one brain metastasis. The dose distribution were calculated using Eclipse treatment planning system with Acuros XB algorithm. The treatment planning of the same target were also done for Cyberknife M6 machine with Multiplan treatment planning system using Monte Carlo algorithm. Using the same film batch, the net OD to dose calibration curve was obtained using both machine by delivering 0- 800 cGy. Films were scanned 48 hours after irradiation using an Epson 1000XL flatbed scanner. Dose distribution were measured using EBT3 film dosimeter. The measured and calculated doses were compared. Results: The dose distribution in the target and 2 cm beyond the target edge were calculated on TPSs and measured using EBT3 film. For cyberknife plans, the gamma analysis passing rates between measured and calculated dose distributions were 99.2% and 96.7% for target and peripheral region of target respectively. For Truebeam plans, the gamma analysis passing rates were 99.1% and 95.5% for target and peripheral region of target respectively. Conclusion: Although, target dose distribution calculated accurately by Acuros XB and Monte Carlo algorithms, Monte carlo calculation algorithm predicts dose distribution around the peripheral region of target more accurately than Acuros algorithm.

  12. Evaluation of Dose Uncertainty to the Target Associated With Real-Time Tracking Intensity-Modulated Radiation Therapy Using the CyberKnife Synchrony System.

    PubMed

    Iwata, Hiromitsu; Inoue, Mitsuhiro; Shiomi, Hiroya; Murai, Taro; Tatewaki, Koshi; Ohta, Seiji; Okawa, Kohei; Yokota, Naoki; Shibamoto, Yuta

    2016-02-01

    We investigated the dose uncertainty caused by errors in real-time tracking intensity-modulated radiation therapy (IMRT) using the CyberKnife Synchrony Respiratory Tracking System (SRTS). Twenty lung tumors that had been treated with non-IMRT real-time tracking using CyberKnife SRTS were used for this study. After validating the tracking error in each case, we did 40 IMRT planning using 8 different collimator sizes for the 20 patients. The collimator size was determined for each planning target volume (PTV); smaller ones were one-half, and larger ones three-quarters, of the PTV diameter. The planned dose was 45 Gy in 4 fractions prescribed at 95% volume border of the PTV. Thereafter, the tracking error in each case was substituted into calculation software developed in house and randomly added in the setting of each beam. The IMRT planning incorporating tracking errors was simulated 1000 times, and various dose data on the clinical target volume (CTV) were compared with the original data. The same simulation was carried out by changing the fraction number from 1 to 6 in each IMRT plan. Finally, a total of 240 000 plans were analyzed. With 4 fractions, the change in the CTV maximum and minimum doses was within 3.0% (median) for each collimator. The change in D99 and D95 was within 2.0%. With decreases in the fraction number, the CTV coverage rate and the minimum dose decreased and varied greatly. The accuracy of real-time tracking IMRT delivered in 4 fractions using CyberKnife SRTS was considered to be clinically acceptable.

  13. Monte Carlo simulated correction factors for machine specific reference field dose calibration and output factor measurement using fixed and iris collimators on the CyberKnife system

    NASA Astrophysics Data System (ADS)

    Francescon, P.; Kilby, W.; Satariano, N.; Cora, S.

    2012-06-01

    Monte Carlo (MC) simulation of dose to water and dose to detector has been used to calculate the correction factors needed for dose calibration and output factor measurements on the CyberKnife system. Reference field ionization chambers simulated were the PTW 30006, Exradin A12, and NE 2571 Farmer chambers, and small volume chambers PTW 31014 and 31010. Correction factors for Farmer chambers were found to be 0.7%-0.9% larger than those determined from TRS-398 due mainly to the dose gradient across the chamber cavity. For one microchamber where comparison was possible, the factor was 0.5% lower than TRS-398 which is consistent with previous MC simulations of flattening filter free Linacs. Output factor detectors simulated were diode models PTW 60008, 60012, 60017, 60018, Sun Nuclear edge detector, air-filled microchambers Exradin A16 and PTW 31014, and liquid-filled microchamber PTW 31018 microLion. Factors were generated for both fixed and iris collimators. The resulting correction factors differ from unity by up to +11% for air-filled microchambers and -6% for diodes at the smallest field size (5 mm), and tend towards unity with increasing field size (correction factor magnitude <1% for all detectors at field sizes >15 mm). Output factor measurements performed using these detectors with fixed and iris collimators on two different CyberKnife systems showed initial differences between detectors of >15% at 5 mm field size. After correction the measurements on each unit agreed within ˜1.5% at the smallest field size. This paper provides a complete set of correction factors needed to apply a new small field dosimetry formalism to both collimator types on the CyberKnife system using a range of commonly used detectors.

  14. [Radiotherapy for Graves' ophthalmopathy].

    PubMed

    Kuhnt, T; Müller, A C; Janich, M; Gerlach, R; Hädecke, J; Duncker, G I W; Dunst, J

    2004-11-01

    Graves' ophthalmopathy (GO) is the most frequent extrathyroidal manifestation of Graves' disease, an autoimmune disorder of the thyroid, whereas the precise pathogenesis still remains unclear. In Hashimoto's thyroiditis the occurrence of proptosis is an extremely rare event. The therapy for middle and severe courses of GO shows in partly disappointing results, although several therapy modalities are possible (glucocorticoid therapy, radiotherapy, antithyroid drug treatment, surgery). All these therapies lead in only 40 - 70 % to an improvement of the pathogenic symptoms. An intensive interdisciplinary cooperation is necessary to satisfy the requirements for the treatment of Graves' ophthalmopathy. As a consequence of the very different results of the few of clinical studies that were accomplished with reference to this topic, treatment by radiotherapy in the management of the disease is presently controversially discussed. In the German-speaking countries the radiotherapy is, however, firmly established as a therapy option in the treatment of the moderate disease classes (class 2-5 according to NO SPECS), especially if diplopia is present. This article describes the sequences, dosages and fractionation schemes as well as the risks and side effects of the radiotherapy. Altogether, radiotherapy is assessed as an effective and sure method. The administration of glucocorticoids can take place before the beginning of or during the radiotherapy. For the success of treatment the correct selection of patients who may possibly profit from a radiotherapy is absolutely essential. By realising that GO proceeds normally over a period of 2-5 years, which is followed by a period of fibrotic alteration, the application of the radiotherapy in the early, active phase is indispensable. A precise explanation for the effects of radiotherapy in treatment of the GO does not exist at present. The determination of the most effective irradiation doses was made from retrospectively evaluated

  15. Accuracy of dose measurements and calculations within and beyond heterogeneous tissues for 6 MV photon fields smaller than 4 cm produced by Cyberknife

    SciTech Connect

    Wilcox, Ellen E.; Daskalov, George M.

    2008-06-15

    For the small radiation field sizes used in stereotactic radiosurgery, lateral electronic disequilibrium and steep dose gradients exist in a large portion of these fields, requiring the use of high-resolution measurement techniques. These relatively large areas of electronic disequilibrium make accurate dosimetry as well as dose calculation more difficult, and this is exacerbated in regions of tissue heterogeneity. Tissue heterogeneity was considered insignificant in the brain where stereotactic radiosurgery was first used. However, as this technique is expanded to the head and neck and other body sites, dose calculations need to account for dose perturbations in and beyond air cavities, lung, and bone. In a previous study we have evaluated EBT Gafchromic film (International Specialty Products, Wayne, NJ) for dosimetry and characterization of the Cyberknife radiation beams and found that it was comparable to other common detectors used for small photon beams in solid water equivalent phantoms. In the present work EBT film is used to measure dose in heterogeneous slab phantoms containing lung and bone equivalent materials for the 6 MV radiation beams of diameter 7.5 to 40 mm produced by the Cyberknife (Accuray, Sunnyvale, CA). These measurements are compared to calculations done with both the clinically utilized Raytrace algorithm as well as the newly developed Monte Carlo based algorithm available on the Cyberknife treatment planning system. Within the low density material both the measurements and Monte Carlo calculations correctly model the decrease in dose produced by a loss of electronic equilibrium, whereas the Raytrace algorithm incorrectly predicts an enhancement of dose in this region. Beyond the low density material an enhancement of dose is correctly calculated by both algorithms. Within the high density bone heterogeneity the EBT film measurements represent dose to unit density tissue in bone and agree with the Monte Carlo results when corrected to dose

  16. CyberKnife with Tumor Tracking: An Effective Treatment for High-Risk Surgical Patients with Stage I Non-Small Cell Lung Cancer.

    PubMed

    Chen, Viola J; Oermann, Eric; Vahdat, Saloomeh; Rabin, Jennifer; Suy, Simeng; Yu, Xia; Collins, Sean P; Subramaniam, Deepa; Banovac, Filip; Anderson, Eric; Collins, Brian T

    2012-01-01

    Published data suggests that wedge resection for stage I non-small cell lung cancer (NSCLC) is associated with improved overall survival compared to stereotactic body radiation therapy. We report CyberKnife outcomes for high-risk surgical patients with biopsy-proven stage I NSCLC. PET/CT imaging was completed for staging. Three-to-five gold fiducial markers were implanted in or near tumors to serve as targeting references. Gross tumor volumes (GTVs) were contoured using lung windows; the margins were expanded by 5 mm to establish the planning treatment volume (PTV). Treatment plans were designed using a mean of 156 pencil beams. Doses delivered to the PTV ranged from 42 to 60 Gy in three fractions. The 30 Gy isodose contour extended at least 1 cm from the GTV to eradicate microscopic disease. Treatments were delivered using the CyberKnife system with tumor tracking. Examination and PET/CT imaging occurred at 3 month follow-up intervals. Forty patients (median age 76) with a median maximum tumor diameter of 2.6 cm (range, 1.4-5.0 cm) and a mean post-bronchodilator percent predicted forced expiratory volume in 1 s (FEV1) of 57% (range, 21-111%) were treated. A median dose of 48 Gy was delivered to the PTV over 3-13 days (median, 7 days). The 30 Gy isodose contour extended a mean 1.9 cm from the GTV. At a median 44 months (range, 12-72 months) follow-up, the 3 year Kaplan-Meier locoregional control and overall survival estimates compare favorably with contemporary wedge resection outcomes at 91 and 75%, respectively. CyberKnife is an effective treatment approach for stage I NSCLC that is similar to wedge resection, eradicating tumors with 1-2 cm margins in order to preserve lung function. Prospective randomized trials comparing CyberKnife with wedge resection are necessary to confirm equivalence.

  17. Accelerated Partial Breast Irradiation: Using the CyberKnife as the Radiation Delivery Platform in the Treatment of Early Breast Cancer.

    PubMed

    Vermeulen, Sandra; Cotrutz, Cristian; Morris, Astrid; Meier, Robert; Buchanan, Claire; Dawson, Patricia; Porter, Bruce

    2011-01-01

    We evaluate the CyberKnife (Accuray Incorporated, Sunnyvale, CA, USA) for non-invasive delivery of accelerated partial breast irradiation (APBI) in early breast cancer patients. Between 6/2009 and 5/2011, nine patients were treated with CyberKnife APBI. Normal tissue constraints were imposed as outlined in the National Surgical Adjuvant Breast and Bowel Project B-39/Radiation Therapy Oncology Group 0413 (NSABP/RTOG) Protocol (Vicini and White, 2007). Patients received a total dose of 30 Gy in five fractions (group 1, n = 2) or 34 Gy in 10 fractions (group 2, n = 7) delivered to the planning treatment volume (PTV) defined as the clinical target volume (CTV) +2 mm. The CTV was defined as either the lumpectomy cavity plus 10 mm (n = 2) or 15 mm (n = 7). The cavity was defined by a T2-weighted non-contrast breast MRI fused to a planning non-contrast thoracic CT. The CyberKnife Synchrony system tracked gold fiducials sutured into the cavity wall during lumpectomy. Treatments started 4-5 weeks after lumpectomy. The mean PTV was 100 cm(3) (range, 92-108 cm(3)) and 105 cm(3) (range, 49-241 cm(3)) and the mean PTV isodose prescription line was 70% for groups 1 and 2, respectively. The mean percent of whole breast reference volume receiving 100 and 50% of the dose (V(100) and V(50)) for group 1 was 11% (range, 8-13%) and 23% (range, 16-30%) and for group 2 was 11% (range, 7-14%) and 26% (range, 21-35.0%), respectively. At a median 7 months follow-up (range, 4-26 months), no acute toxicities were seen. Acute cosmetic outcomes were excellent or good in all patients; for those patients with more than 12 months follow-up the late cosmesis outcomes were excellent or good. In conclusion, the lack of observable acute side effects and current excellent/good cosmetic outcomes is promising. We believe this suggests the CyberKnife is a suitable non-invasive radiation platform for delivering APBI with achievable normal tissue constraints.

  18. Radiotherapy for bone pain.

    PubMed Central

    Needham, P R; Mithal, N P; Hoskin, P J

    1994-01-01

    Painful bone metastases are a common problem for cancer patients. Although current evidence supports the use of a single fraction of radiotherapy as the treatment of choice, many radiotherapists, for a variety of reasons, continue to use fractionated regimens. Over one six month period 105 patients received external beam irradiation for painful bone metastases at the Royal London Hospital (RLH). Thirty-one per cent of the patients were aged 70 or over. The treatment of 97 of these patients was assessed. They had a total of 280 sites treated over the course of their disease. Fifty-nine per cent of sites treated received a fractionated course of radiotherapy. Site significantly influenced fractionation. Overall response rates of 82% were achieved. Fractionation did not appear to influence this. Ten patients received large field irradiation. Fifteen patients had five or more sites irradiated, of whom only one received hemibody irradiation. PMID:7523672

  19. The clinical outcome of intracranial hemangioblastomas treated with linac-based stereotactic radiosurgery and radiotherapy

    PubMed Central

    Puataweepong, Putipun; Dhanachai, Mantana; Hansasuta, Ake; Dangprasert, Somjai; Sitathanee, Chomporn; Puddhikarant, Parmon; Jiarpinitnun, Chuleeporn; Ruangkanchanasetr, Rawee; Dechsupa, Patchareporn; Pairat, Kumutinee

    2014-01-01

    Recent publications have reported stereotactic radiosurgery as an effective and safe treatment for intracranial hemangioblastomas. However, because of the low incidence of these particular tumors, reports on large patient number studies have not yet been available. The objective of this study was to analyze the clinical results of 14 patients with 56 intracranial hemangioblastomas treated with linear accelerator (linac)-based stereotactic radiosurgery (SRS) and radiotherapy (SRT) in the same institute. The median age of patients was 41 years (range, 28–73 years). Nine of the patients (64%) had von Hippel-Lindau disease. A total of 39 lesions (70%) were treated with CyberKnife (CK), and 17 lesions (30%) were treated with X-Knife. The median pretreatment volume was 0.26 cm3 (range, 0.026–20.4 cm3). The median marginal dose was 20 Gy (range, 10–32 Gy) in 1 fraction (range, 1–10 fractions). The median follow-up time was 24 months (range, 11–89 months). At the last follow-up, 47 tumors (84%) were stable, 7 (13%) decreased and 2 (4%) increased. The 1-, 2- and 6-year local control rates were 98%, 88% and 73%, respectively. No radiation complications were observed in this study. There was a trend toward local failure only in cystic tumors, but this trend was not found to be statistically significant. SRS/SRT achieved a high local control rate in intracranial hemangioblastomas without radiation-induced complications. PMID:24554558

  20. Melanoma: Last call for radiotherapy.

    PubMed

    Espenel, Sophie; Vallard, Alexis; Rancoule, Chloé; Garcia, Max-Adrien; Guy, Jean-Baptiste; Chargari, Cyrus; Deutsch, Eric; Magné, Nicolas

    2017-02-01

    Melanoma is traditionally considered to be a radioresistant tumor. However, radiotherapy and immunotherapy latest developments might upset this radiobiological dogma. Stereotactic radiotherapy allows high dose per fraction delivery, with high dose rate. More DNA lethal damages, less sublethal damages reparation, endothelial cell apoptosis, and finally clonogenic cell dysfunction are produced, resulting in improved local control. Radiotherapy can also enhance immune responses, inducing neoantigens formation, tumor antigen presentation, and cytokines release. A synergic effect of radiotherapy with immunotherapy is expected, and might lead to abscopal effects. If hadrontherapy biological properties seem able to suppress hypoxia-induced radioresistance and increase biological efficacy, ballistic advantages over photon radiations might also improve radiotherapy outcomes on usually poor prognosis locations. The present review addresses biological and clinical effects of high fraction dose, bystander effect, abscopal effect, and hadrontherapy features in melanoma. Clinical trials results are warranted to establish indications of innovative radiotherapy in melanoma.

  1. Accident prevention in radiotherapy

    PubMed Central

    Holmberg, O

    2007-01-01

    In order to prevent accidents in radiotherapy, it is important to learn from accidents that have occurred previously. Lessons learned from a number of accidents are summarised and underlying patterns are looked for in this paper. Accidents can be prevented by applying several safety layers of preventive actions. Categories of these preventive actions are discussed together with specific actions belonging to each category of safety layer. PMID:21614274

  2. [Radiotherapy of bladder cancer].

    PubMed

    Riou, O; Chauvet, B; Lagrange, J-L; Martin, P; Llacer Moscardo, C; Charissoux, M; Lauche, O; Aillères, N; Fenoglietto, P; Azria, D

    2016-09-01

    Surgery (radical cystectomy) is the standard treatment of muscle-invasive bladder cancer. Radiochemotherapy has risen as an alternative treatment option to surgery as part as organ-sparing combined modality treatment or for patients unfit for surgery. Radiochemotherapy achieves 5-year bladder intact survival of 40 to 65% and 5-year overall survival of 40 to 50% with excellent quality of life. This article introduces the French recommendations for radiotherapy of bladder cancer: indications, exams, technique, dosimetry, delivery and image guidance.

  3. Improving plan quality and consistency by standardization of dose constraints in prostate cancer patients treated with CyberKnife.

    PubMed

    Descovich, Martina; Carrara, Mauro; Morlino, Sara; Pinnaduwage, Dilini S; Saltiel, Daniel; Pouliot, Jean; Nash, Marc B; Pignoli, Emanuele; Valdagni, Riccardo; Roach, Mack; Gottschalk, Alexander R

    2013-09-06

    Treatment plans for prostate cancer patients undergoing stereotactic body radiation therapy (SBRT) are often challenging due to the proximity of organs at risk. Today, there are no objective criteria to determine whether an optimal treatment plan has been achieved, and physicians rely on their personal experience to evaluate the plan's quality. In this study, we propose a method for determining rectal and bladder dose constraints achievable for a given patient's anatomy. We expect that this method will improve the overall plan quality and consistency, and facilitate comparison of clinical outcomes across different institutions. The 3D proximity of the organs at risk to the target is quantified by means of the expansion-intersection volume (EIV), which is defined as the intersection volume between the target and the organ at risk expanded by 5 mm. We determine a relationship between EIV and relevant dosimetric parameters, such as the volume of bladder and rectum receiving 75% of the prescription dose (V75%). This relationship can be used to establish institution-specific criteria to guide the treatment planning and evaluation process. A database of 25 prostate patients treated with CyberKnife SBRT is used to validate this approach. There is a linear correlation between EIV and V75% of bladder and rectum, confirming that the dose delivered to rectum and bladder increases with increasing extension and proximity of these organs to the target. This information can be used during the planning stage to facilitate the plan optimization process, and to standardize plan quality and consistency. We have developed a method for determining customized dose constraints for prostate patients treated with robotic SBRT. Although the results are technology specific and based on the experience of a single institution, we expect that the application of this method by other institutions will result in improved standardization of clinical practice.

  4. Direct plan comparison of RapidArc and CyberKnife for spine stereotactic body radiation therapy

    NASA Astrophysics Data System (ADS)

    Choi, Young Eun; Kwak, Jungwon; Song, Si Yeol; Choi, Eun Kyung; Ahn, Seung Do; Cho, Byungchul

    2015-07-01

    We compared the treatment planning performance of RapidArc (RA) vs. CyberKnife (CK) for spinal stereotactic body radiation therapy (SBRT). Ten patients with spinal lesions who had been treated with CK were re-planned with RA, which consisted of two complete arcs. Computed tomography (CT) and volumetric dose data of CK, generated using the Multiplan (Accuray) treatment planning system (TPS) and the Ray-trace algorithm, were imported to Varian Eclipse TPS in Dicom format, and the data were compared with the RA plan by using an analytical anisotropic algorithm (AAA) dose calculation. The optimized dose priorities for both the CK and the RA plans were similar for all patients. The highest priority was to provide enough dose coverage to the planned target volume (PTV) while limiting the maximum dose to the spinal cord. Plan quality was evaluated with respect to PTV coverage, conformity index (CI), high-dose spillage, intermediate-dose spillage (R50% and D2cm), and maximum dose to the spinal cord, which are criteria recommended by the RTOG 0631 spine and 0915 lung SBRT protocols. The mean CI' SD values of the PTV were 1.11' 0.03 and 1.17' 0.10 for RA and CK ( p = 0.02), respectively. On average, the maximum dose delivered to the spinal cord in CK plans was approximately 11.6% higher than that in RA plans, and this difference was statistically significant ( p < 0.001). High-dose spillages were 0.86% and 2.26% for RA and CK ( p = 0.203), respectively. Intermediate-dose spillage characterized by D2cm was lower for RA than for CK; however, R50% was not statistically different. Even though both systems can create highly conformal volumetric dose distributions, the current study shows that RA demonstrates lower high- and intermediate-dose spillages than CK. Therefore, RA plans for spinal SBRT may be superior to CK plans.

  5. Dosimetric impacts of endorectal balloon in CyberKnife stereotactic body radiation therapy (SBRT) for early-stage prostate cancer.

    PubMed

    Xiang, Hong F; Lu, Hsiao-Ming; Efstathiou, Jason A; Zietman, Anthony L; Armas, Ricardo De; Harris, Kathryn; Bloch, B Nicolas; Qureshi, Muhammad Mustafa; Keohan, Sean; Hirsch, Ariel E

    2017-05-01

    In SBRT for prostate cancer, higher fractional dose to the rectum is a major toxicity concern due to using smaller PTV margin and hypofractionation. We investigate the dosimetric impact on rectum using endorectal balloon (ERB) in prostate SBRT. Twenty prostate cancer patients were included in a retrospective study, ten with ERB and 10 without ERB. Optimized SBRT plans were generated on CyberKnife MultiPlan for 5 × 7.25 Gy to PTV under RTOG-0938 protocol for early-stage prostate cancer. For the rectum and the anterior half rectum, mean dose and percentage of volumes receiving 50%, 80%, 90%, and 100% prescription dose were compared. Using ERB, mean dose to the rectum was 62 cGy (P = 0.001) lower per fraction, and 50 cGy (P = 0.024) lower per fraction for the anterior half rectum. The average V50% , V80% , V90% , and V100% were lower by 9.9% (P = 0.001), 5.3% (P = 0.0002), 3.4% (P = 0.0002), and 1.2% (P = 0.005) for the rectum, and lower by 10.4% (P = 0.009), 8.3% (P = 0.0004), 5.4% (P = 0.0003), and 2.1% (P = 0.003) for the anterior half rectum. Significant reductions of dose to the rectum using ERB were observed. This may lead to improvement of the rectal toxicity profiles in prostate SBRT. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  6. TU-F-CAMPUS-T-03: A Novel Iris Quality Assurance Phantom for the CyberKnife Radiosurgery System

    SciTech Connect

    Descovich, M; Pinnaduwage, D; Sudhyadhom, A; Nelson, B

    2015-06-15

    Purpose: A novel CCD camera and conical scintillator based phantom that is capable of measuring the targeting and field size accuracy of a robotic radiosurgery system has been developed. This work investigates its application in measuring the field sizes and beam divergence of the CyberKnife variable aperture collimator (Iris). Methods: The phantom was placed on the treatment couch and the robot position was adjusted to obtain an anterior -posterior beam perpendicular to the cone’s central axis. The FWHM of the 12 Iris apertures (5, 7.5, 10, 12.5, 15, 20, 25, 30, 35, 40, 50, and 60 mm) were measured from the beam flux map on the conical scintillator surface as seen by the CCD camera. For each measurement 30 MU were delivered to the phantom at a dose rate of 1000 MU/min. The measurements were repeated at 4 SAD distances between 75 and 85 cm. These readings were used to project the aperture size as if the flux map on the scintillator were located 80 cm from the source (SSD). These projected FWHM beam diameters were then compared to the commissioning data. Results: A series of 12 beam divergence equations were obtained from the 4 sets of data using linear trend lines on Excel scatter plots. These equations were then used to project the FWHM measurements at 80 cm SSD. The average aperture accuracy for beams from 5 through 40 mm was 0.08 mm. The accuracy for the 50 and 60 mm beams were 0.33 and 0.58 mm when compared to film commissioning data. Conclusion: The experimental results for 10 apertures agree with the stated Iris accuracy of ±0.2 mm at 80 cm SAD. The results for the 50 and 60 mm aperture were repeatable and can serve as a reliable trend indicator of any deviations away from the commissioning values. Brett Nelson is President/CTO of Logos Systems.

  7. Clinical Accuracy of the Respiratory Tumor Tracking System of the CyberKnife: Assessment by Analysis of Log Files

    SciTech Connect

    Hoogeman, Mischa Prevost, Jean-Briac; Nuyttens, Joost; Poell, Johan; Levendag, Peter; Heijmen, Ben

    2009-05-01

    Purpose: To quantify the clinical accuracy of the respiratory motion tracking system of the CyberKnife treatment device. Methods and Materials: Data in log files of 44 lung cancer patients treated with tumor tracking were analyzed. Errors in the correlation model, which relates the internal target motion with the external breathing motion, were quantified. The correlation model error was compared with the geometric error obtained when no respiratory tracking was used. Errors in the prediction method were calculated by subtracting the predicted position from the actual measured position after 192.5 ms (the time lag to prediction in our current system). The prediction error was also measured for a time lag of 115 ms and a new prediction method. Results: The mean correlation model errors were less than 0.3 mm. Standard deviations describing intrafraction variations around the whole-fraction mean error were 0.2 to 1.9 mm for cranio-caudal, 0.1 to 1.9 mm for left-right, and 0.2 to 2.5 mm for anterior-posterior directions. Without the use of respiratory tracking, these variations would have been 0.2 to 8.1 mm, 0.2 to 5.5 mm, and 0.2 to 4.4 mm. The overall mean prediction error was small (0.0 {+-} 0.0 mm) for all directions. The intrafraction standard deviation ranged from 0.0 to 2.9 mm for a time delay of 192.5 ms but was halved by using the new prediction method. Conclusions: Analyses of the log files of real clinical cases have shown that the geometric error caused by respiratory motion is substantially reduced by the application of respiratory motion tracking.

  8. SU-E-T-448: Switch Patients between Collimation Systems for CyberKnife Treatment Feasibility Study.

    PubMed

    Fan, J; Xu, Q; Wang, L; Jin, L; Li, J; Lin, T; Hayes, S; Tam, T; Ma, C

    2012-06-01

    There are two collimation systems associated with the CyberKnife system, the fixed cone collimator and the Iris collimator. The Iris collimator is used more frequently because of its superior flexibility. However, sometimes treatments have to be canceled or postponed due to Iris collimator mechanical failures. The purpose of this study is to investigate the feasibility of switching collimation systems without replanning. We first performed Monte Carlo simulations on 10 clinical cases using the Iris collimator and the fixed cone collimator. The conformality index (CI), target volume coverage and the maximum, minimum and mean doses to the critical structures from the iris and fixed plans were compared to determine the feasibility of switching between collimator types without replanning. Our results showed that the two types of collimators deliver similar dose distributions. The average target doses for the fixed plans were 1% to 6% higher than those for the Iris plans. The average CI for the fixed plans was 1.36 compared to 1.28 for the Iris plans. Thus, we adjusted the Iris sizes with a scale factor of 1.024 to achieve a better dose match with the fixed collimators. Doses for the 10 cases were then recalculated. Once this correction was made, the difference between the average target doses for the two collimator plans was reduced to less than 2% and the CIs became almost identical. Small target dose differences were found between plans using different collimation systems, which may be compensated for by adjusting the Iris collimator sizes to ensure similar dose distributions. The differences in the doses to the critical structures between the collimation systems were insignificant. After adjusting the Iris collimator sizes and re-commissioning the planning system, patients can be safely switched from the Iris collimator to the fixed cone collimator without replanning. © 2012 American Association of Physicists in Medicine.

  9. Radiotherapy DICOM packet sniffing.

    PubMed

    Ackerly, T; Gesoand, M; Smith, R

    2008-09-01

    The Digital Imaging and Communications in Medicine (DICOM) standard is meant to allow communication of medical images between equipment provided by different vendors, but when two applications do not interact correctly in a multi-vendor environment it is often first necessary to demonstrate non-compliance of either the sender or the receiver before a resolution to the problem can be progressed. Sometimes the only way to do this is to monitor the network communication between the two applications to find out which one is not complying with the DICOM standard. Packet sniffing is a technique of network traffic analysis by passive observation of all information transiting a point on the network, regardless of the specified sender or receiver. DICOM packet sniffing traps and interprets the network communication between two DICOM applications to determine which is non compliant. This is illustrated with reference to three examples, a radiotherapy planning system unable to receive CT data from a particular CT scanner, a radiotherapy simulator unable to print correctly on a DICOM printer, and a PACS unable to respond when queried about what images it has in its archive by a radiotherapy treatment planning system. Additionally in this work it has been proven that it is feasible to extract DICOM images from the intercepted network data. This process can be applied to determine the cause of a DICOM image being rendered differently by the sender and the receiver.

  10. Imaging in radiotherapy.

    PubMed

    Van den Berge, D L; De Ridder, M; Storme, G A

    2000-10-01

    Radiotherapy, more then any other treatment modality, relies heavily and often exclusively on medical imaging to determine the extent of disease and the spatial relation between target region and neighbouring healthy tissues. Radically new approaches to radiation delivery are inspired on CT scanning and treat patients in a slice-by-slice fashion using intensity modulated megavoltage fan beams. For quality assurance of complex 3-D dose distributions, MR based 3-D verificative dosimetry on irradiated phantoms has been described. As treatment delivery becomes increasingly refined, the need for accurate target definition increases as well and sophisticated imaging tools like image fusion and 3-D reconstruction are routinely used for treatment planning. While in the past patients were positioned on the treatment machines based exclusively on surface topography and the well-known skin marks, such approach is no longer sufficient for high-accuracy radiotherapy and special imaging tools like on-line portal imaging are used to verify and correct target positioning. Much of these applications rely on digital image processing, transmission and storage, and the development of standards, like DICOM and PACS have greatly contributed to these applications. Digital imaging plays an increasing role in many areas in radiotherapy and has been fundamental in new developments that have demonstrated impact on patient care.

  11. [Radiotherapy for primary lung carcinoma].

    PubMed

    Giraud, P; Lacornerie, T; Mornex, F

    2016-09-01

    Indication, doses, technique of radiotherapy and concomitant chemotherapy, for primary lung carcinoma are presented. The recommendations for delineation of the target volumes and organs at risk are detailed.

  12. [Radiotherapy of breast cancer].

    PubMed

    Hennequin, C; Barillot, I; Azria, D; Belkacémi, Y; Bollet, M; Chauvet, B; Cowen, D; Cutuli, B; Fourquet, A; Hannoun-Lévi, J M; Leblanc, M; Mahé, M A

    2016-09-01

    In breast cancer, radiotherapy is an essential component of the treatment. After conservative surgery for an infiltrating carcinoma, radiotherapy must be systematically performed, regardless of the characteristics of the disease, because it decreases the rate of local recurrence and by this way, specific mortality. Partial breast irradiation could not be proposed routinely but only in very selected and informed patients. For ductal carcinoma in situ, adjuvant radiotherapy must be also systematically performed after lumpectomy. After mastectomy, chest wall irradiation is required for pT3-T4 tumours and if there is an axillary nodal involvement, whatever the number of involved lymph nodes. After neo-adjuvant chemotherapy and mastectomy, in case of pN0 disease, chest wall irradiation is recommended if there is a clinically or radiologically T3-T4 or node positive disease before chemotherapy. Axillary irradiation is recommended only if there is no axillary surgical dissection and a positive sentinel lymph node. Supra and infra-clavicular irradiation is advised in case of positive axillary nodes. Internal mammary irradiation must be discussed case by case, according to the benefit/risk ratio (cardiac toxicity). Dose to the chest wall or the breast must be between 45-50Gy with a conventional fractionation. A boost dose over the tumour bed is required if the patient is younger than 60 years old. Hypofractionation (42.5 Gy in 16 fractions, or 41.6 Gy en 13 or 40 Gy en 15) is possible after tumorectomy and if a nodal irradiation is not mandatory. Delineation of the breast, the chest wall and the nodal areas are based on clinical and radiological evaluations. 3D-conformal irradiation is the recommended technique, intensity-modulated radiotherapy must be proposed only in case of specific clinical situations. Respiratory gating could be useful to decrease the cardiac dose. Concomitant administration of chemotherapy in unadvised, but hormonal treatment could be start with

  13. Caring for children undergoing radiotherapy treatment: Swedish radiotherapy nurses' perceptions.

    PubMed

    Gårdling, J; Edwinson Månsson, M; Törnqvist, E; Hallström, I

    2015-12-01

    The aim was to explore radiotherapy nurses' perceptions of their experiences of caring for children undergoing radiotherapy treatment for cancer. Semi-structured interviews of 12 nurses were conducted. The interviews were analysed using a phenomenographical approach. All interviewees were women, and the group's mean age was 49 years. Caring for children during radiotherapy treatment was perceived as a complex task. Their perceptions included views on providing holistic care, creating a sense of security and being committed. Through holistic care the radiotherapy nurses took responsibility regarding care for the child and family, technical aspects of the radiotherapy procedure and the development of their profession. They tried to create a sense of security through individualized information and preparation, through teamwork with the child and family, and regarding anaesthetic personnel (if needed) while balancing the care they gave related to the child, to the family, to anaesthetic personnel, and to their own tasks. The radiotherapy nurses perceived themselves as committed in their care and reported being emotionally affected by sadness, but also joy. By clarifying radiotherapy nurses perceptions of caring for children guidelines can be developed to lessen anxiety and increase the sense of security amongst children undergoing radiotherapy treatment and their family members. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Efficacy of stereotactic body radiotherapy for hepatocellular carcinoma with portal vein tumor thrombosis/inferior vena cava tumor thrombosis: evaluation by comparison with conventional three-dimensional conformal radiotherapy

    PubMed Central

    Matsuo, Yoshiro; Yoshida, Kenji; Nishimura, Hideki; Ejima, Yasuo; Miyawaki, Daisuke; Uezono, Haruka; Ishihara, Takeaki; Mayahara, Hiroshi; Fukumoto, Takumi; Ku, Yonson; Yamaguchi, Masato; Sugimoto, Koji; Sasaki, Ryohei

    2016-01-01

    This study aimed to evaluate the efficacy of stereotactic body radiotherapy (SBRT) compared with three-dimensional conformal radiotherapy (3DCRT). Forty-three patients with portal vein tumor thrombosis (PVTT)/inferior vena cava tumor thrombosis (IVCTT) treated with SBRT (27 with CyberKnife (CK) and 16 with TrueBeam (TB)) from April 2013 to December 2014, and 54 treated with 3DCRT from June 2008 to March 2013 were evaluated. Dosimetric parameters, response to radiotherapy (RT) and survival outcomes were compared in total SBRT vs. 3DCRT, CK vs. 3DCRT and TB vs. 3DCRT, respectively. The median biologically effective dose 10 (BED10) values in total SBRT, CK, TB and 3DCRT were 73.4 Gy10, 75.0 Gy10, 60.5 Gy10 and 58.5 Gy10, respectively (P < 0.001 in total SBRT vs. 3DCRT, P < 0.001 in CK vs. 3DCRT, P = 0.004 in TB vs. 3DCRT). The tumor response rates were 67%, 70%, 62% and 46%, respectively (P = 0.04, P = 0.04, P = 0.25). The 1-year overall survival rates were 49.3%, 56.7%, 38.1% and 29.3%, respectively (P = 0.02, P = 0.02, P = 0.30), and the 1-year local progression rates were 20.4%, 21.9%, 18.8% and 43.6%, respectively (P = 0.01, P = 0.04, P = 0.10). The use of SBRT made it possible to achieve a higher BED10 compared with the use of 3DCRT. Improvements in local control and survival were achieved in the CK group and the total SBRT group. Our results suggest that SBRT may have the potential to be the standard RT technique for the treatment of PVTT/IVCTT. PMID:27053259

  15. Demand for radiotherapy in Spain.

    PubMed

    Rodríguez, A; Borrás, J M; López-Torrecilla, J; Algara, M; Palacios-Eito, A; Gómez-Caamaño, A; Olay, L; Lara, P C

    2017-02-01

    Assessing the demand for radiotherapy in Spain based on existing evidence to estimate the human resources and equipment needed so that every person in Spain has access to high-quality radiotherapy when they need it. We used data from the European Cancer Observatory on the estimated incidence of cancer in Spain in 2012, along with the evidence-based indications for radiotherapy developed by the Australian CCORE project, to obtain an optimal radiotherapy utilisation proportion (OUP) for each tumour. About 50.5 % of new cancers in Spain require radiotherapy at least once over the course of the disease. Additional demand for these services comes from reradiation therapy and non-melanoma skin cancer. Approximately, 25-30 % of cancer patients with an indication for radiotherapy do not receive it due to factors that include access, patient preference, familiarity with the treatment among physicians, and especially resource shortages, all of which contribute to its underutilisation. Radiotherapy is underused in Spain. The increasing incidence of cancer expected over the next decade and the greater frequency of reradiations necessitate the incorporation of radiotherapy demand into need-based calculations for cancer services planning.

  16. Particle radiotherapy for prostate cancer.

    PubMed

    Shioyama, Yoshiyuki; Tsuji, Hiroshi; Suefuji, Hiroaki; Sinoto, Makoto; Matsunobu, Akira; Toyama, Shingo; Nakamura, Katsumasa; Kudo, Sho

    2015-01-01

    Recent advances in external beam radiotherapy have allowed us to deliver higher doses to the tumors while decreasing doses to the surrounding tissues. Dose escalation using high-precision radiotherapy has improved the treatment outcomes of prostate cancer. Intensity-modulated radiation therapy has been widely used throughout the world as the most advanced form of photon radiotherapy. In contrast, particle radiotherapy has also been under development, and has been used as an effective and non-invasive radiation modality for prostate and other cancers. Among the particles used in such treatments, protons and carbon ions have the physical advantage that the dose can be focused on the tumor with only minimal exposure of the surrounding normal tissues. Furthermore, carbon ions also have radiobiological advantages that include higher killing effects on intrinsic radio-resistant tumors, hypoxic tumor cells and tumor cells in the G0 or S phase. However, the degree of clinical benefit derived from these theoretical advantages in the treatment of prostate cancer has not been adequately determined. The present article reviews the available literature on the use of particle radiotherapy for prostate cancer as well as the literature on the physical and radiobiological properties of this treatment, and discusses the role and the relative merits of particle radiotherapy compared with current photon-based radiotherapy, with a focus on proton beam therapy and carbon ion radiotherapy.

  17. 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.

  18. Bystander effects and radiotherapy.

    PubMed

    Marín, Alicia; Martín, Margarita; Liñán, Olga; Alvarenga, Felipe; López, Mario; Fernández, Laura; Büchser, David; Cerezo, Laura

    2015-01-01

    Radiation-induced bystander effects are defined as biological effects expressed after irradiation by cells whose nuclei have not been directly irradiated. These effects include DNA damage, chromosomal instability, mutation, and apoptosis. There is considerable evidence that ionizing radiation affects cells located near the site of irradiation, which respond individually and collectively as part of a large interconnected web. These bystander signals can alter the dynamic equilibrium between proliferation, apoptosis, quiescence or differentiation. The aim of this review is to examine the most important biological effects of this phenomenon with regard to areas of major interest in radiotherapy. Such aspects include radiation-induced bystander effects during the cell cycle under hypoxic conditions when administering fractionated modalities or combined radio-chemotherapy. Other relevant aspects include individual variation and genetics in toxicity of bystander factors and normal tissue collateral damage. In advanced radiotherapy techniques, such as intensity-modulated radiation therapy (IMRT), the high degree of dose conformity to the target volume reduces the dose and, therefore, the risk of complications, to normal tissues. However, significant doses can accumulate out-of-field due to photon scattering and this may impact cellular response in these regions. Protons may offer a solution to reduce out-of-field doses. The bystander effect has numerous associated phenomena, including adaptive response, genomic instability, and abscopal effects. Also, the bystander effect can influence radiation protection and oxidative stress. It is essential that we understand the mechanisms underlying the bystander effect in order to more accurately assess radiation risk and to evaluate protocols for cancer radiotherapy.

  19. Bystander effects and radiotherapy

    PubMed Central

    Marín, Alicia; Martín, Margarita; Liñán, Olga; Alvarenga, Felipe; López, Mario; Fernández, Laura; Büchser, David; Cerezo, Laura

    2014-01-01

    Radiation-induced bystander effects are defined as biological effects expressed after irradiation by cells whose nuclei have not been directly irradiated. These effects include DNA damage, chromosomal instability, mutation, and apoptosis. There is considerable evidence that ionizing radiation affects cells located near the site of irradiation, which respond individually and collectively as part of a large interconnected web. These bystander signals can alter the dynamic equilibrium between proliferation, apoptosis, quiescence or differentiation. The aim of this review is to examine the most important biological effects of this phenomenon with regard to areas of major interest in radiotherapy. Such aspects include radiation-induced bystander effects during the cell cycle under hypoxic conditions when administering fractionated modalities or combined radio-chemotherapy. Other relevant aspects include individual variation and genetics in toxicity of bystander factors and normal tissue collateral damage. In advanced radiotherapy techniques, such as intensity-modulated radiation therapy (IMRT), the high degree of dose conformity to the target volume reduces the dose and, therefore, the risk of complications, to normal tissues. However, significant doses can accumulate out-of-field due to photon scattering and this may impact cellular response in these regions. Protons may offer a solution to reduce out-of-field doses. The bystander effect has numerous associated phenomena, including adaptive response, genomic instability, and abscopal effects. Also, the bystander effect can influence radiation protection and oxidative stress. It is essential that we understand the mechanisms underlying the bystander effect in order to more accurately assess radiation risk and to evaluate protocols for cancer radiotherapy. PMID:25535579

  20. [Radiotherapy during pregnancy].

    PubMed

    Mazeron, R; Barillot, I; Mornex, F; Giraud, P

    2016-09-01

    The diagnostic of cancer during pregnancy is a rare and delicate situation. As the developments of the embryo and the human fetus are extremely sensitive to ionizing radiations, the treatment of these tumors should be discussed. The studies - preclinical and clinical - based mostly on exposure accidents show that subdiaphragmatic treatments are possible during pregnancy. When radiotherapy is used, phantom estimations of the dose to the fetus, confirmed by in vivo measurements are required. Irradiation and imaging techniques should be arranged to decrease as much as possible the dose delivered to the fetus and hold below the threshold of 0.1Gy.

  1. Radiotherapy in the UK

    SciTech Connect

    Ramsay, S.

    1993-10-09

    What is wrong with radiation treatment in the UK Is it bad practice or merely bad publicity Between 1982 and 1991, 1,000 patients receiving isocentric radiation therapy at the North Staffordshire Royal Infirmary received a substantial underdose of radiation; the clinical report on this incident was published last week. The operator had been using a correction factor for tumor-to-skin distance, unaware that this factor had already been applied by the computer system. Although the report pointed out that it is not surprising that the clinicians were not alerted to the undertreatment, is also noted that there were no resources at the hospital to audit the outcome of radiotherapy.

  2. SU-E-T-224: Is Monte Carlo Dose Calculation Method Necessary for Cyberknife Brain Treatment Planning?

    SciTech Connect

    Wang, L; Fourkal, E; Hayes, S; Jin, L; Ma, C

    2014-06-01

    Purpose: To study the dosimetric difference resulted in using the pencil beam algorithm instead of Monte Carlo (MC) methods for tumors adjacent to the skull. Methods: We retrospectively calculated the dosimetric differences between RT and MC algorithms for brain tumors treated with CyberKnife located adjacent to the skull for 18 patients (total of 27 tumors). The median tumor sizes was 0.53-cc (range 0.018-cc to 26.2-cc). The absolute mean distance from the tumor to the skull was 2.11 mm (range - 17.0 mm to 9.2 mm). The dosimetric variables examined include the mean, maximum, and minimum doses to the target, the target coverage (TC) and conformality index. The MC calculation used the same MUs as the RT dose calculation without further normalization and 1% statistical uncertainty. The differences were analyzed by tumor size and distance from the skull. Results: The TC was generally reduced with the MC calculation (24 out of 27 cases). The average difference in TC between RT and MC was 3.3% (range 0.0% to 23.5%). When the TC was deemed unacceptable, the plans were re-normalized in order to increase the TC to 99%. This resulted in a 6.9% maximum change in the prescription isodose line. The maximum changes in the mean, maximum, and minimum doses were 5.4 %, 7.7%, and 8.4%, respectively, before re-normalization. When the TC was analyzed with regards to target size, it was found that the worst coverage occurred with the smaller targets (0.018-cc). When the TC was analyzed with regards to the distance to the skull, there was no correlation between proximity to the skull and TC between the RT and MC plans. Conclusions: For smaller targets (< 4.0-cc), MC should be used to re-evaluate the dose coverage after RT is used for the initial dose calculation in order to ensure target coverage.

  3. SU-E-T-804: Verification of the BJR-25 Method of KQ Determination for CyberKnife Absolute Dosimetry

    SciTech Connect

    Gersh, J; Willett, B

    2015-06-15

    Purpose: Absolute calibration of the CyberKnife is performed using a 6cm-diameter cone defined at 80cm SAD. Since kQ is defined using PDD values determined using 10×10 cm fields at 100cm SSD, the PDD must be corrected in order to correctly apply the quality conversion factor. The accepted method is based on equivalent field-size conversions of PDD values using BJR25. Using the new InCise MLC system, the CK is capable of generating a rectangular field equivalent to 10×10 cm square field. In this study, a comparison is made between kQ values determined using the traditional BJR25 method and the MLC method introduced herein. Methods: First, kQ(BJR) is determined: a PDD is acquired using a 6cm circular field at 100cm SSD, its field size converted to an equivalent square, and PDD converted to a 10×10cm field using the appropriate BJR25 table. Maintaining a consistent setup, the collimator is changed, and the MLC method is used. Finally, kQ is determined using PDDs acquired with a 9.71×10.31cm at 100cm SSD. This field is produced by setting the field to a size of 7.77×8.25cm (since it is defined at 80cm SAD). An exact 10×10cm field since field size is relegated to increments of its leaf width (0.25cm). This comparison is made using an Exradin A1SL, IBA CC08, IBA CC13, and an Exradin A19. For each detector and collimator type, the beam injector was adjusted to give 5 different beam qualities; representing a range of clinical systems. Results: Averaging across all beam qualities, kQ(MLC) differed from kQ(BJR) by less than 0.15%. The difference between the values increased with detector volume. Conclusion: For CK users with standard cone collimators, the BJR25 method has been verified. For CK users the MLC system, a technique is described to determine kQ. Primary author is the President/Owner of Spectrum Medical Physics, LLC, a company which maintains contracts with Siemens Healthcare and Standard Imaging, Inc.

  4. SU-E-T-619: Comparison of CyberKnife Versus HDR (SAVI) for Partial Breast Irradiation

    SciTech Connect

    Mooij, R; Ding, X; Nagda, S

    2014-06-15

    Purpose: Compare SAVI plans and CyberKnife (CK) plans for the same accelerated course. Methods and Materials: Three SAVI patients were selected. Pre-SAVI CTs were used for CK planning. All prescriptions are 3400cGy in 10 fractions BID. Max dose to skin and chestwall is 425cGy. For SAVI, PTV is a 1cm expansion of the cavity minus the cavity. For CK, CTV is a 1cm expansion of the seroma, with 2mm margin. CK plans are normalized to SAVI, so that in both cases the 323cGy isodose line covers the same percentage of PTV. For CK Fiducial/Synchrony tracking is used. Results: In the following, all doses are per fraction and results are averaged. The PTVs for the CK plans are 2.4 times larger than the corresponding SAVI PTVs. Nonetheless the CK plans meet all constraints and are superior to SAVI plans in several respects. Max skin dose for SAVI vs CK is 332cGy vs 337cGy. Max dose to chestwall is 252cGy vs 286cGy. The volume of lung over 125cGy is 6.4cc for SAVI and 2.5cc for CK. Max heart dose is 60cGy for SAVI and 83cGy for CK. The volume of PTV receiving over 425cGy is 49cc for SAVI and 1.3cc for CK. Max dose to contra-lateral breast is 16cGy for SAVI and 4.5cGy for CK. Conclusion: CK PTVs are directly derived from the seroma. Corresponding SAVI PTVs tend to be much smaller. Dosimetrically, CK plans are equivalent or superior to SAVI plans despite the larger PTVs. Interestingly, the dose delivered to the lung is higher in SAVI vs CK. Fiducial/Synchrony tracking employed by CK might reduce errors in delivery compared to errors associated with shifts of the SAVI implant. In conclusion, when CK is an option for partial breast irradiation it may preferable to SAVI.

  5. [Hodgkin's lymphoma and radiotherapy].

    PubMed

    Datsenko, P V; Panshin, G A

    2015-01-01

    After a median observation time of 4,5 years, 440 patients with Hodgkin's lymphoma stage I-IV to the Ann Arbor classification were treated with radiotherapy (2200 lymph areas) and ABVD (n=204) or BEACOPP (n=117) or CEA/ABVD (lomustine, etoposide, adriamycine, bleomycine, vinblastine and dacarbacine; n=119) regimens in 1995-2012. Correct allocation of groups with "CR or PR ≥80%" and "PR: 0-79%", after first-line chemotherapy, is extremely important for following RT planning. Adaptation of patients with Hodgkin's lymphoma can take place only after successful treatment, the probability of relapse and fear of repeated courses strongly interfere with this process, especially in the first years after its closure. Duration of remission period, especially in young people, is no less important than the criteria for overall survival. It is impossible to build recommendations for treatment for Hodgkin's lymphoma, based only on long-term survival rates. Importance of radiotherapy in reducing the number of relapses is undeniable, so the idea that the development of the role of chemotherapy in the treatment of the ray method Hodgkin's lymphoma gradually becomes secondary is in serious doubt. Our findings suggest the importance of both maintaining a high disease-free survival and reducing long-term complications in designing treatments of Hodgkin's lymphoma.

  6. Fertility impairment in radiotherapy

    PubMed Central

    Kuźba-Kryszak, Tamara; Nowikiewicz, Tomasz; Żyromska, Agnieszka

    2016-01-01

    Infertility as a result of antineoplastic therapy is becoming a very important issue due to the growing incidence of neoplastic diseases. Routinely applied antineoplastic treatments and the illness itself lead to fertility disorders. Therapeutic methods used in antineoplastic treatment may cause fertility impairment or sterilization due to permanent damage to reproductive cells. The risk of sterilization depends on the patient's sex, age during therapy, type of neoplasm, radiation dose and treatment area. It is known that chemotherapy and radiotherapy can lead to fertility impairment and the combination of these two gives an additive effect. The aim of this article is to raise the issue of infertility in these patients. It is of growing importance due to the increase in the number of children and young adults who underwent radiotherapy in the past. The progress in antineoplastic therapy improves treatment results, but at the same time requires a deeper look at existential needs of the patient. Reproductive function is an integral element of self-esteem and should be taken into account during therapy planning. PMID:27647982

  7. Imaging in radiotherapy

    NASA Astrophysics Data System (ADS)

    Calandrino, R.; Del Maschio, A.; Cattaneo, G. M.; Castiglioni, I.

    2009-09-01

    The diagnostic methodologies used for the radiotherapy planning have undergone great developments in the last 30 years. Since the 1980s, after the introduction of the CT scanner, the modality for the planning moved beyond the planar 2D assessment to approach a real and more realistic volumetric 3D definition. Consequently the dose distribution, previously obtained by means of an overly simple approximation, became increasingly complex, better tailoring the true shape of the tumour. The final therapeutic improvement has been obtained by a parallel increase in the complexity of the irradiating units: the Linacs for therapy have, in fact, been equipped with a full accessory set capable to modulate the fluence (IMRT) and to check the correct target position continuously during the therapy session (IMRT-IGRT). The multimodal diagnostic approach, which integrates diagnostic information, from images of the patient taken with CT, NMR, PET and US, further improves the data for a biological and topological optimization of the radiotherapy plan and consequently of the dose distribution in the Planning Target Volume. Proteomic and genomic analysis will be the next step in tumour diagnosis. These methods will provide the planners with further information, for a true personalization of the treatment regimen and the assessment of the predictive essays for each tumour and each patient.

  8. [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.

  9. SU-E-J-06: Additional Imaging Guidance Dose to Patient Organs Resulting From X-Ray Tubes Used in CyberKnife Image Guidance System

    SciTech Connect

    Sullivan, A; Ding, G

    2015-06-15

    Purpose: The use of image-guided radiation therapy (IGRT) has become increasingly common, but the additional radiation exposure resulting from repeated image guidance procedures raises concerns. Although there are many studies reporting imaging dose from different image guidance devices, imaging dose for the CyberKnife Robotic Radiosurgery System is not available. This study provides estimated organ doses resulting from image guidance procedures on the CyberKnife system. Methods: Commercially available Monte Carlo software, PCXMC, was used to calculate average organ doses resulting from x-ray tubes used in the CyberKnife system. There are seven imaging protocols with kVp ranging from 60 – 120 kV and 15 mAs for treatment sites in the Cranium, Head and Neck, Thorax, and Abdomen. The output of each image protocol was measured at treatment isocenter. For each site and protocol, Adult body sizes ranging from anorexic to extremely obese were simulated since organ dose depends on patient size. Doses for all organs within the imaging field-of-view of each site were calculated for a single image acquisition from both of the orthogonal x-ray tubes. Results: Average organ doses were <1.0 mGy for every treatment site and imaging protocol. For a given organ, dose increases as kV increases or body size decreases. Higher doses are typically reported for skeletal components, such as the skull, ribs, or clavicles, than for softtissue organs. Typical organ doses due to a single exposure are estimated as 0.23 mGy to the brain, 0.29 mGy to the heart, 0.08 mGy to the kidneys, etc., depending on the imaging protocol and site. Conclusion: The organ doses vary with treatment site, imaging protocol and patient size. Although the organ dose from a single image acquisition resulting from two orthogonal beams is generally insignificant, the sum of repeated image acquisitions (>100) could reach 10–20 cGy for a typical treatment fraction.

  10. 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.

  11. Intraoperative radiotherapy for breast cancer.

    PubMed

    Vaidya, Jayant S; Tobias, Jeffrey S; Baum, Michael; Keshtgar, Mohammed; Joseph, David; Wenz, Frederik; Houghton, Joan; Saunders, Christobel; Corica, Tammy; D'Souza, Derek; Sainsbury, Richard; Massarut, Samuele; Taylor, Irving; Hilaris, Basil

    2004-03-01

    Postoperative radiotherapy, which forms part of breast-conserving therapy, may not need to encompass the whole breast. Apart from the consumption of huge resources and patients' time, postoperative radiotherapy deters many women from receiving the benefits of breast-conserving surgery, forcing them to choose a mastectomy instead. If radiotherapy could be given in the operating theatre immediately after surgery, many of these disadvantages could be overcome. One striking fact about local recurrence after breast-conserving surgery is that most occurs in the area of breast immediately next to the primary tumour; this is despite the finding that two-thirds of mastectomy samples have microscopic tumours distributed throughout the breast, even when radiotherapy is omitted. Thus, only the area adjacent to the tumour may need treatment with radiotherapy. On the basis of this premise, clinical scientists have used new technology to administer radiotherapy to the area at greatest risk of local recurrence, with the aim of completing the whole local treatment in one sitting. In this review, we have elaborated on the rationale and different methods of delivery of intraoperative radiotherapy. If this approach is validated by the results of current randomised trials, it could save time, money, and breasts.

  12. Pituitary radiotherapy for Cushing's disease.

    PubMed

    Losa, Marco; Picozzi, Piero; Redaelli, Maria Grazia; Laurenzi, Andrea; Mortini, Pietro

    2010-01-01

    The treatment of choice for Cushing's disease is pituitary surgery. Second-line treatments include repeat pituitary surgery, radiation therapy, medical therapy, and bilateral adrenalectomy. The most used modalities to irradiate patients with Cushing's disease include fractionated radiotherapy and single-dose Gamma Knife. We aim to review the efficacy and safety of radiotherapy in patients with persistent or recurring Cushing's disease. Remission of Cushing's disease after radiotherapy ranges from 42 to 83%. There seems to be no clear difference according to the technique of radiation used. Most patients experience remission of disease within 3 years from treatment, with only few cases reaching normal cortisol secretion after a longer follow-up. Control of tumor growth varies from 93 to 100%. Severe side effects of radiotherapy, such as optic neuropathy and radionecrosis, are uncommon. New-onset hypopituitarism is the most frequent side effect of radiation, occurring in 30-50% of patients treated by fractionated radiotherapy while it has been reported in 11-22% of patients after Gamma Knife. Radiotherapy is an effective second-line treatment in patients with Cushing's disease not cured by surgery. Consideration of the advantages and disadvantages of radiotherapy in comparison with other therapeutic options should always be carried out in the single patient before deciding the second-line therapeutic strategy for persisting or recurring Cushing's disease. Copyright © 2010 S. Karger AG, Basel.

  13. Radiotherapy in Phyllodes Tumour

    PubMed Central

    Sasidharan, Balukrishna; Manipadam, Marie Therese; Paul, M J; Backianathan, Selvamani

    2017-01-01

    Introduction Phyllodes Tumour (PT) of the breast is a relatively rare breast neoplasm (<1%) with diverse range of pathology and biological behaviour. Aim To describe the clinical course of PT and to define the role of Radiotherapy (RT) in PT of the breast. Materials and Methods Retrospective analysis of hospital data of patients with PT presented from 2005 to 2014 was done. Descriptive statistics was used to analyze the results. Simple description of data was done in this study. Age and duration of symptoms were expressed in median and range. Percentages, tables and general discussions were used to understand the meaning of the data analyzed. Results Out of the 98 patients, 92 were eligible for analysis. The median age of presentation was 43 years. A total of 64/92 patients were premenopausal. There was no side predilection for this tumour but 57/92 patients presented as an upper outer quadrant lump. Fifty percent of the patients presented as giant (10 cm) PT. The median duration of symptoms was 12 months (range: 1-168 months). A 60% of patients had Benign (B), 23% had Borderline (BL) and 17% had malignant (M) tumours. The surgical treatment for benign histology included Lumpectomy (L) for 15%, Wide Local Excision (WLE) for 48%, and Simple Mastectomy (SM) for 37%. All BL and M tumours were treated with WLE or SM. There was no recurrence in B and BL group when the margin was ≥1 cm. All non-metastatic M tumours received adjuvant RT irrespective of their margin status. Total 3/16 patients with M developed local recurrence. Total 6/16 M patients had distant metastases (lung or bone). Our median duration of follow up was 20 months (range: 1-120 months). Conclusion Surgical resection with adequate margins (>1 cm) gave excellent local control in B and BL tumours. For patients with BL PT, local radiotherapy is useful, if margins are close or positive even after the best surgical resection. There is a trend towards improved local control with adjuvant radiotherapy for

  14. [Respiratory synchronization and breast radiotherapy].

    PubMed

    Mège, A; Ziouèche-Mottet, A; Bodez, V; Garcia, R; Arnaud, A; de Rauglaudre, G; Pourel, N; Chauvet, B

    2016-10-01

    Adjuvant radiation therapy following breast cancer surgery continues to improve locoregional control and overall survival. But the success of highly targeted-conformal radiotherapy such as intensity-modulated techniques, can be compromised by respiratory motion. The intrafraction motion can potentially result in significant under- or overdose, and also expose organs at risk. This article summarizes the respiratory motion and its effects on imaging, dose calculation and dose delivery by radiotherapy for breast cancer. We will review the methods of respiratory synchronization available for breast radiotherapy to minimize the respiratory impact and to spare organs such as heart and lung.

  15. [Task sharing with radiotherapy technicians in image-guided radiotherapy].

    PubMed

    Diaz, O; Lorchel, F; Revault, C; Mornex, F

    2013-10-01

    The development of accelerators with on-board imaging systems now allows better target volumes reset at the time of irradiation (image-guided radiotherapy [IGRT]). However, these technological advances in the control of repositioning led to a multiplication of tasks for each actor in radiotherapy and increase the time available for the treatment, whether for radiotherapy technicians or radiation oncologists. As there is currently no explicit regulatory framework governing the use of IGRT, some institutional experiments show that a transfer is possible between radiation oncologists and radiotherapy technicians for on-line verification of image positioning. Initial training for every technical and drafting procedures within institutions will improve audit quality by reducing interindividual variability.

  16. [Hepatic tumors and radiotherapy].

    PubMed

    Rio, E; Mornex, F; Peiffert, D; Huertas, A

    2016-09-01

    Recent technological developments led to develop the concept of focused liver radiation therapy. We must distinguish primary and secondary tumors as the indications are restricted and must be discussed as an alternative to surgical or medical treatments. For hepatocellular carcinoma 5 to 10cm (or more), a conformational radiation with or without intensity modulation is performed. Stereotactic body radiotherapy (SBRT) is being evaluated and is increasingly proposed as an alternative to radiofrequency ablative treatment for primary or secondary tumors (typically less than 5cm). Tumor (and liver) movements induced by respiratory motions must be taken into account. Strict dosimetric criteria must be met with particular attention to the dose-volume histograms to liver and the hollow organs, including cases of SBRT.

  17. [Radiotherapy for nasopharyngeal carcinoma].

    PubMed

    Maingon, P; Blanchard, P; Bidault, F; Calmels, L

    2016-09-01

    Nasapharyngeal carcinoma is a rare disease. Oftenly, the diagnostic is made for advanced disease. Localized tumors, T1 or T2 NO observed a good prognosis and are locally controlled in more than 90 % of the cases by radiotherapy alone. The standard treatment of locally advanced disease is combined chemoradiation. A special vigilance of fast decrease of the volume of the pathological lymph nodes, sometimes associated to loss of weight might indicate an adaptive dosimetric revision. The treatment of recurrent disease is of great importance. Surgical indications are limited but should be discussed in multidisciplinary tumor board when possible. Surgical nodal sampling has to be proposed for nodal recurrence as well as reirradiation, which could be indicated according to the technical issues.

  18. Radiotherapy Planning using MRI

    PubMed Central

    Schmidt, Maria A; Payne, Geoffrey S

    2016-01-01

    The use of Magnetic Resonance Imaging (MRI) in Radiotherapy (RT) planning is rapidly expanding. We review the wide range of image contrast mechanisms available to MRI and the way they are exploited for RT planning. However a number of challenges are also considered: the requirements that MR images are acquired in the RT treatment position, that they are geometrically accurate, that effects of patient motion during the scan are minimised, that tissue markers are clearly demonstrated, that an estimate of electron density can be obtained. These issues are discussed in detail, prior to the consideration of a number of specific clinical applications. This is followed by a brief discussion on the development of real-time MRI-guided RT. PMID:26509844

  19. Radiotherapy on hidradenocarcinoma

    PubMed Central

    Lalya, Issam; Hadadi, Khalid; Tazi, El Mehdi; Lalya, Ilham; Bazine, Amine; Andaloussy, Khalid; Elmarjany, Mohamed; Sifat, Hassan; Hassouni, Khalid; Kebdani, Tayeb; Mansouri, Hamid; Benjaafar, Noureddine; Elgueddari, Brahim Khalil

    2011-01-01

    Context: Clear cell Hidradenocarcinoma is a rare carcinoma arising from sweat glands. It is an aggressive tumor that most metastasizes to regional lymph nodes and distant viscera; surgery with safe margins is the mainstay of treatment. Case Report: We report a case of 68-year-old woman who presented with an invasive clear cell hidradenocarcinoma situated in the left parotid area which recurred 5 months after surgery, this recurrence was managed successfully by high-dose irradiation of the tumor bed (66 Gy) and regional lymphatic chains (50 Gy), after a follow-up of more than 15 months, the patient is in good local control without significant toxicity. Conclusion: Post operative radiotherapy allows better local control and should be mandatory when histological features predictive of recurrence are present: positive margins, histology poorly differentiated, perineural invasion, vascular and lymphatic invasion, lymph node involvement, and extracapsular spread. PMID:22540063

  20. Pion radiotherapy at LAMPF

    SciTech Connect

    Bush, S.E.; Smith, A.R.; Zink, S.

    1982-12-01

    Clinical investigations of pi meson radiotherapy were conducted by the Cancer Research and Treatment Center of the University of New Mexico and the Los Alamos National Laboratory from 1974 until 1982. Two hundred and thirty patients have been treated for a variety of locally advanced primary and metastatic neoplasms. One hundred and ninety-six patients have been followed for a minimum of 18 months. Crude survival data range from 11% for unresectable pancreatic carcinoma to 82% for Stages C and D1 adenocarcinoma of the prostate. Acute tolerance of normal tissues is approximately 4500 pion rad in 36 fractions over 7 weeks. Severe chronic reactions have appeared with increasing frequency after doses in excess of 4000 pion rad.

  1. Dosimetric comparison between cone/Iris-based and InCise MLC-based CyberKnife plans for single and multiple brain metastases.

    PubMed

    Jang, Si Young; Lalonde, Ron; Ozhasoglu, Cihat; Burton, Steven; Heron, Dwight; Huq, M Saiful

    2016-09-01

    We performed an evaluation of the CyberKnife InCise MLC by comparing plan qualities for single and multiple brain lesions generated using the first version of InCise MLC, fixed cone, and Iris collimators. We also investigated differences in delivery efficiency among the three collimators. Twenty-four patients with single or multiple brain mets treated previously in our clinic on a CyberKnife M6 using cone/Iris collimators were selected for this study. Treatment plans were generated for all lesions using the InCise MLC. Number of monitor units, delivery time, target coverage, conformity index, and dose falloff were compared between MLC- and clinical cone/Iris-based plans. Statistical analysis was performed using the nonparametric Wilcoxon-Mann-Whitney signed-rank test. The planning accuracy of the MLC-based plans was validated using chamber and film measurements. The InCise MLC-based plans achieved mean dose and target coverage comparable to the cone/Iris-based plans. Although the conformity indices of the MLC-based plans were slightly higher than those of the cone/Iris-based plans, beam delivery time for the MLC-based plans was shorter by 30%∼40%. For smaller targets or cases with OARs located close to or abutting target volumes, MLC-based plans provided inferior dose conformity compared to cone/Iris-based plans. The QA results of MLC-based plans were within 5% absolute dose difference with over 90% gamma passing rate using 2%/2 mm gamma criteria. The first version of InCise MLC could be a useful delivery modality, especially for clinical situations for which delivery time is a limiting factor or for multitarget cases. PACS number(s): 87.53.Ly, 87.55.D.

  2. Dosimetric comparison between cone/Iris-based and InCise MLC-based CyberKnife plans for single and multiple brain metastases.

    PubMed

    Jang, Si Young; Lalonde, Ron; Ozhasoglu, Cihat; Burton, Steven; Heron, Dwight; Huq, M Saiful

    2016-09-08

    We performed an evaluation of the CyberKnife InCise MLC by comparing plan qualities for single and multiple brain lesions generated using the first version of InCise MLC, fixed cone, and Iris collimators. We also investigated differences in delivery efficiency among the three collimators. Twenty-four patients with single or multiple brain mets treated previously in our clinic on a CyberKnife M6 using cone/Iris collimators were selected for this study. Treatment plans were generated for all lesions using the InCise MLC. Number of monitor units, delivery time, target coverage, conformity index, and dose falloff were compared between MLC- and clinical cone/Iris-based plans. Statistical analysis was performed using the non-parametric Wilcoxon-Mann-Whitney signed-rank test. The planning accuracy of the MLC-based plans was validated using chamber and film measurements. The InCise MLC-based plans achieved mean dose and target coverage comparable to the cone/Iris-based plans. Although the conformity indices of the MLC-based plans were slightly higher than those of the cone/Iris-based plans, beam delivery time for the MLC-based plans was shorter by 30% ~ 40%. For smaller targets or cases with OARs located close to or abutting target volumes, MLC-based plans provided inferior dose conformity compared to cone/Iris-based plans. The QA results of MLC-based plans were within 5% absolute dose difference with over 90% gamma passing rate using 2%/2 mm gamma criteria. The first version of InCise MLC could be a useful delivery modality, especially for clinical situations for which delivery time is a limiting factor or for multitarget cases.

  3. Bone Health and Pelvic Radiotherapy.

    PubMed

    Higham, C E; Faithfull, S

    2015-11-01

    Survivors who have received pelvic radiotherapy make up many of the long-term cancer population, with therapies for gynaecological, bowel, bladder and prostate malignancies. Individuals who receive radiotherapy to the pelvis as part of their cancer treatment are at risk of insufficiency fractures. Symptoms of insufficiency fractures include pelvic and back pain and immobility, which can affect substantially quality of life. This constellation of symptoms can occur within 2 months of radiotherapy up to 63 months post-treatment, with a median incidence of 6-20 months. As a condition it is under reported and evidence is poor as to the contributing risk factors, causation and best management to improve the patient's bone health and mobility. As radiotherapy advances, chronic symptoms, such as insufficiency fractures, as a consequence of treatment need to be better understood and reviewed. This overview explores the current evidence for the effect of radiotherapy on bone health and insufficiency fractures and identifies what we know and where gaps in our knowledge lie. The overview concludes with the need to take seriously complaints of pelvic pain from patients after pelvic radiotherapy and to investigate and manage these symptoms more effectively. There is a clear need for definitive research in this field to provide the evidence-based guidance much needed in practice.

  4. 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

  5. Robotic image-guided stereotactic radiotherapy, for isolated recurrent primary, lymph node or metastatic prostate cancer.

    PubMed

    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

    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. 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, [(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). 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. CyberKnife-based stereotactic radiotherapy is a feasible approach for isolated recurrent primary, lymph node, or metastatic prostate cancer, offering excellent in-field tumor control and a low toxicity profile. Further investigation

  6. 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

  7. Real-time monitoring system with accelerator controlling: An improvement of radiotherapy monitoring based on binocular location and classification.

    PubMed

    Chai, Lei; Chen, Da; Tang, Xiao-Bing; Ge, Yun; Chen, Ying; Li, Jun

    2017-02-21

    Real-time monitoring and amendment of patient position is important for the radiotherapy. However, using electronic portal imaging device (EPID) and cone beam computer tomography (CBCT) in the clinical practice generate different degrees of delay, so that they cannot achieve the purpose of real-time application. Meanwhile, a few products come with the function of the real-time monitoring and amendment, such as CyberKnife, which is too expensive for the common people. The objective of this study is to develop and test a novel independent system to monitor treatment center and amend the position of patient, which is applicable to most accelerators, based on binocular location. The system monitors the treatment center by tracking the markers attached to the patient. Once the treatment center shifts, the system uses the magic finger, which is developed to control the treatment bet automatically to adjust the treatment bed position. To improve the monitoring accuracy, we trained the data collected from the clinic based on SVM (Support Vector Machine). Thus, the training results assist users to adjust the feasible degree of the monitoring. The experiment results showed that using this new monitoring system, the monitoring resolution reached 0.5 mm, and the error ratio of the judgment was less than 1.5%.

  8. Smoothing of respiratory motion traces for motion-compensated radiotherapy

    SciTech Connect

    Ernst, Floris; Schlaefer, Alexander; Schweikard, Achim

    2010-01-15

    Purpose: The CyberKnife system has been used successfully for several years to radiosurgically treat tumors without the need for stereotactic fixation or sedation of the patient. It has been shown that tumor motion in the lung, liver, and pancreas can be tracked with acceptable accuracy and repeatability. However, highly precise targeting for tumors in the lower abdomen, especially for tumors which exhibit strong motion, remains problematic. Reasons for this are manifold, like the slow tracking system operating at 26.5 Hz, and using the signal from the tracking camera ''as is''. Since the motion recorded with the camera is used to compensate for system latency by prediction and the predicted signal is subsequently used to infer the tumor position from a correlation model based on x-ray imaging of gold fiducials around the tumor, camera noise directly influences the targeting accuracy. The goal of this work is to establish the suitability of a new smoothing method for respiratory motion traces used in motion-compensated radiotherapy. The authors endeavor to show that better prediction--With a lower rms error of the predicted signal--and/or smoother prediction is possible using this method. Methods: The authors evaluated six commercially available tracking systems (NDI Aurora, PolarisClassic, Polaris Vicra, MicronTracker2 H40, FP5000, and accuTrack compact). The authors first tracked markers both stationary and while in motion to establish the systems' noise characteristics. Then the authors applied a smoothing method based on the a trous wavelet decomposition to reduce the devices' noise level. Additionally, the smoothed signal of the moving target and a motion trace from actual human respiratory motion were subjected to prediction using the MULIN and the nLMS{sub 2} algorithms. Results: The authors established that the noise distribution for a static target is Gaussian and that when the probe is moved such as to mimic human respiration, it remains Gaussian with the

  9. Prostate-specific antigen kinetics after stereotactic body radiotherapy as monotherapy or boost after whole pelvic radiotherapy for localized prostate cancer

    PubMed Central

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

    2015-01-01

    Purpose Stereotactic body radiotherapy (SBRT) has emerged as an effective treatment for localized prostate cancer. However, prostate-specific antigen (PSA) kinetics after SBRT has not been well characterized. The purpose of the current study is to assess the kinetics of PSA for low- and intermediate-risk prostate cancer patients treated with SBRT using Cyberknife as both monotherapy and boost after whole pelvic radiotherapy (WPRT) in the absence of androgen deprivation therapy. Methods A total of 61 patients with low- and intermediated-risk prostate cancer treated with SBRT as monotherapy (36.25 Gy in 5 fractions in 32 patients) and SBRT (21 Gy in 3 fractions in 29 patients) boost combined with WPRT (45 Gy in 25 fractions). Patients were excluded if they failed therapy by the Phoenix definition or had androgen deprivation therapy. PSA nadir and rate of change in PSA over time (slope) were calculated and compared. Results With a median follow-up of 52.4 months (range, 14–74 months), for SBRT monotherapy, the median PSA nadir was 0.31 ng/mL (range, 0.04–1.15 ng/mL) and slopes were –0.41 ng/mL/mo, –0.17 ng/mL/mo, –0.12 ng/mL/mo, and –0.09 ng/mL/mo, respectively, for durations of 1 year, 2 years, 3 years, and 4 years postradiotherapy. Similarly, for SBRT boost after WPRT, the median PSA nadir was 0.34 ng/mL (range, 0.04–1.44 ng/mL) and slopes were –0.53 ng/mL/mo, –0.25 ng/mL/mo, –0.14 ng/mL/mo, and –0.09 ng/mL/mo, respectively. The median nadir and slopes of SBRT monotherapy did not differ significantly from those of SBRT boost after WPRT. Benign PSA bounces were common in 30.4% of all cohorts, and the median time to PSA bounce was 12 months (range, 6–25 months). Conclusions In this report of low- and intermediate-risk prostate cancer patients, an initial period of rapid PSA decline was followed by a slow decline, which resulted in a lower PSA nadir. The PSA kinetics of SBRT monotherapy appears to be comparable to those achieved

  10. [Adaptative radiotherapy: The case for MRI-guided radiotherapy].

    PubMed

    Maingon, P

    2016-10-01

    The concept of image-guided radiotherapy benefits from the development of magnetic resonance imaging (MRI) associated with different capacities of tissue analyses such as spectroscopy or diffusion analysis. The production of devices allowing the repositioning of patients through MRI represents a strong added value without delivering any additional dose to the patient while the optimization of the adaptative strategies are facilitated by a better contrast of the soft tissues compared to the scanner. The advantages of MRI are well demonstrated for brain tumours, head and neck carcinomas, pelvic tumors, mediastinal malignancies, gastrointestinal tract diseases. Adaptative radiotherapy inaugurates a new area of radiotherapy with different modalities. Several technological solutions are provided or discussed allowing the patients to benefit from thses new technologies as soon as possible.

  11. [Postoperative radiotherapy of prostate cancer].

    PubMed

    Guérif, S; Latorzeff, I; Lagrange, J-L; Hennequin, C; Supiot, S; Garcia, A; François, P; Soulié, M; Richaud, P; Salomon, L

    2014-10-01

    Between 10 and 40% of patients who have undergone a radical prostatectomy may have a biologic recurrence. Local or distant failure represents the possible patterns of relapse. Patients at high-risk for local relapse have extraprostatic disease, positive surgical margins or seminal vesicles infiltration or high Gleason score at pathology. Three phase-III randomized clinical trials have shown that, for these patients, adjuvant irradiation reduces the risk of tumoral progression without higher toxicity. Salvage radiotherapy for late relapse allows a disease control in 60-70% of the cases. Several research in order to improve the therapeutic ratio of the radiotherapy after prostatectomy are evaluate in the French Groupe d'Étude des Tumeurs Urogénitales (Gétug) and of the French association of urology (Afu). The Gétug-Afu 17 trial will provide answers to the question of the optimal moment for postoperative radiotherapy for pT3-4 R1 pN0 Nx patients, with the objective of comparing an immediate treatment to a differed early treatment initiated at biological recurrence. The Gétug-Afu 22 questions the place of a short hormonetherapy combined with image-guided, intensity-modulated radiotherapy (IMRT) in adjuvant situation for a detectable prostate specific antigen (PSA). The implementation of a multicenter quality control within the Gétug-Afu in order to harmonize a modern postoperative radiotherapy will allow the development of a dose escalation IMRT after surgery.

  12. 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.

  13. 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.

  14. [Head and neck adaptive radiotherapy].

    PubMed

    Graff, P; Huger, S; Kirby, N; Pouliot, J

    2013-10-01

    Onboard volumetric imaging systems can provide accurate data of the patient's anatomy during a course of head and neck radiotherapy making it possible to assess the actual delivered dose and to evaluate the dosimetric impact of complex daily positioning variations and gradual anatomic changes such as geometric variations of tumors and normal tissues or shrinkage of external contours. Adaptive radiotherapy is defined as the correction of a patient's treatment planning to adapt for individual variations observed during treatment. Strategies are developed to selectively identify patients that require replanning because of an intolerable dosimetric drift. Automated tools are designed to limit time consumption. Deformable image registration algorithms are the cornerstones of these strategies, but a better understanding of their limits of validity is required before adaptive radiotherapy can be safely introduced to daily practice. Moreover, strict evaluation of the clinical benefits is yet to be proven.

  15. Expanding global access to radiotherapy.

    PubMed

    Atun, Rifat; Jaffray, David A; Barton, Michael B; Bray, Freddie; Baumann, Michael; Vikram, Bhadrasain; Hanna, Timothy P; Knaul, Felicia M; Lievens, Yolande; Lui, Tracey Y M; Milosevic, Michael; O'Sullivan, Brian; Rodin, Danielle L; Rosenblatt, Eduardo; Van Dyk, Jacob; Yap, Mei Ling; Zubizarreta, Eduardo; Gospodarowicz, Mary

    2015-09-01

    Radiotherapy is a critical and inseparable component of comprehensive cancer treatment and care. For many of the most common cancers in low-income and middle-income countries, radiotherapy is essential for effective treatment. In high-income countries, radiotherapy is used in more than half of all cases of cancer to cure localised disease, palliate symptoms, and control disease in incurable cancers. Yet, in planning and building treatment capacity for cancer, radiotherapy is frequently the last resource to be considered. Consequently, worldwide access to radiotherapy is unacceptably low. We present a new body of evidence that quantifies the worldwide coverage of radiotherapy services by country. We show the shortfall in access to radiotherapy by country and globally for 2015-35 based on current and projected need, and show substantial health and economic benefits to investing in radiotherapy. The cost of scaling up radiotherapy in the nominal model in 2015-35 is US$26·6 billion in low-income countries, $62·6 billion in lower-middle-income countries, and $94·8 billion in upper-middle-income countries, which amounts to $184·0 billion across all low-income and middle-income countries. In the efficiency model the costs were lower: $14·1 billion in low-income, $33·3 billion in lower-middle-income, and $49·4 billion in upper-middle-income countries-a total of $96·8 billion. Scale-up of radiotherapy capacity in 2015-35 from current levels could lead to saving of 26·9 million life-years in low-income and middle-income countries over the lifetime of the patients who received treatment. The economic benefits of investment in radiotherapy are very substantial. Using the nominal cost model could produce a net benefit of $278·1 billion in 2015-35 ($265·2 million in low-income countries, $38·5 billion in lower-middle-income countries, and $239·3 billion in upper-middle-income countries). Investment in the efficiency model would produce in the same period an even

  16. Introduction to suspension levels: radiotherapy.

    PubMed

    Horton, P; Lillicrap, S; Lamm, I-L; Lehmann, W

    2013-02-01

    In 2007, the European Commission (EC) commissioned a group of experts to undertake the revision of Report Radiation Protection (RP 91) 'Criteria for acceptability of radiological (including radiotherapy) and nuclear medicine installations' written in 1997. The revised draft report was submitted to the EC in 2010, who issued it for public consultation. The EC has commissioned the same group of experts to consider the comments of the public consultation for further improvement of the revised report. The EC intends to publish the final report under its Radiation Report Series as RP 162. This paper describes the background to the selection of the key performance parameters for radiotherapy equipment and sets out the sources of their criteria of acceptability including suspension levels for a wide range of radiotherapy equipment.

  17. Inflammatory Skin Conditions Associated With Radiotherapy.

    PubMed

    Hernández Aragüés, I; Pulido Pérez, A; Suárez Fernández, R

    2017-04-01

    Radiotherapy for cancer is used increasingly. Because skin cells undergo rapid turnover, the ionizing radiation of radiotherapy has collateral effects that are often expressed in inflammatory reactions. Some of these reactions-radiodermatitis and recall phenomenon, for example-are very familiar to dermatologists. Other, less common radiotherapy-associated skin conditions are often underdiagnosed but must also be recognized.

  18. Stereotactic linear accelerator radiotherapy for pituitary tumors.

    PubMed

    Ajithkumar, Thankama; Brada, Michael

    2004-01-01

    Last decade has seen important advances in radiotherapy technology which combine precise tumor localization with accurate targeted delivery of radiation. This technique of high precision conformal radiotherapy, described as stereotactic radiotherapy or radiosurgery, uses modern linear accelerators available in most radiation oncology departments. The article describes the new technique as applied to the treatment of pituitary adenoma and reviews published clinical results.

  19. Radiotherapy supports protective tumor-specific immunity

    PubMed Central

    Gupta, Anurag; Sharma, Anu; von Boehmer, Lotta; Surace, Laura; Knuth, Alexander; van den Broek, Maries

    2012-01-01

    Radiotherapy is an important therapeutic option for the treatment of cancer. Growing evidence indicates that, besides inducing an irreversible DNA damage, radiotherapy promotes tumor-specific immune response, which significantly contribute to therapeutic efficacy. We postulate that radiotherapy activates tumor-associated dendritic cells, thus changing the tolerogenic tumor environment into an immunogenic one. PMID:23264910

  20. Clinical quality standards for radiotherapy

    PubMed Central

    2012-01-01

    Aim of the study The technological progress that is currently being witnessed in the areas of diagnostic imaging, treatment planning systems and therapeutic equipment has caused radiotherapy to become a high-tech and interdisciplinary domain involving staff of various backgrounds. This allows steady improvement in therapy results, but at the same time makes the diagnostic, imaging and therapeutic processes more complex and complicated, requiring every stage of those processes to be planned, organized, controlled and improved so as to assure high quality of services provided. The aim of this paper is to present clinical quality standards for radiotherapy as developed by the author. Material and methods In order to develop the quality standards, a comparative analysis was performed between European and Polish legal acts adopted in the period of 1980-2006 and the universal industrial ISO 9001:2008 standard, defining requirements for quality management systems, and relevant articles published in 1984-2009 were reviewed, including applicable guidelines and recommendations of American, international, European and Polish bodies, such as the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy & Oncology (ESTRO), the International Atomic Energy Agency (IAEA), and the Organisation of European Cancer Institutes (OECI) on quality assurance and management in radiotherapy. Results As a result, 352 quality standards for radiotherapy were developed and categorized into the following three groups: 1 – organizational standards; 2 – physico-technical standards and 3 – clinical standards. Conclusion Proposed clinical quality standards for radiotherapy can be used by any institution using ionizing radiation for medical purposes. However, standards are of value only if they are implemented, reviewed, audited and improved, and if there is a clear mechanism in place to monitor and address failure to meet agreed standards. PMID:23788854

  1. Second Malignant Neoplasms Following Radiotherapy

    PubMed Central

    Kumar, Sanath

    2012-01-01

    More than half of all cancer patients receive radiotherapy as a part of their treatment. With the increasing number of long-term cancer survivors, there is a growing concern about the risk of radiation induced second malignant neoplasm [SMN]. This risk appears to be highest for survivors of childhood cancers. The exact mechanism and dose-response relationship for radiation induced malignancy is not well understood, however, there have been growing efforts to develop strategies for the prevention and mitigation of radiation induced cancers. This review article focuses on the incidence, etiology, and risk factors for SMN in various organs after radiotherapy. PMID:23249860

  2. Metrological Issues in Molecular Radiotherapy

    NASA Astrophysics Data System (ADS)

    D'Arienzo, Marco; Capogni, Marco; Smyth, Vere; Cox, Maurice; Johansson, Lena; Solc, Jaroslav; Bobin, Christophe; Rabus, Hans; Joulaeizadeh, Leila

    2014-08-01

    The therapeutic effect from molecular radiation therapy (MRT), on both tumour and normal tissue, is determined by the radiation absorbed dose. Recent research indicates that as a consequence of biological variation across patients the absorbed dose can vary, for the same administered activity, by as much as two orders of magnitude. The international collaborative EURAMET-EMRP project "Metrology for molecular radiotherapy (MetroMRT)" is addressing this problem. The overall aim of the project is to develop methods of calibrating and verifying clinical dosimetry in MRT. In the present paper an overview of the metrological issues in molecular radiotherapy is provided.

  3. [Which rules apply to hypofractionated radiotherapy?].

    PubMed

    Supiot, S; Clément-Colmou, K; Paris, F; Corre, I; Chiavassa, S; Delpon, G

    2015-10-01

    Hypofractionated radiotherapy is now more widely prescribed due to improved targeting techniques (intensity modulated radiotherapy, image-guided radiotherapy and stereotactic radiotherapy). Low dose hypofractionated radiotherapy is routinely administered mostly for palliative purposes. High or very high dose hypofractionated irradiation must be delivered according to very strict procedures since every minor deviation can lead to major changes in dose delivery to the tumor volume and organs at risk. Thus, each stage of the processing must be carefully monitored starting from the limitations and the choice of the hypofractionation technique, tumour contouring and dose constraints prescription, planning and finally dose calculation and patient positioning verification.

  4. External radiotherapy in thyroid cancers

    SciTech Connect

    Tubiana, M.; Haddad, E.; Schlumberger, M.; Hill, C.; Rougier, P.; Sarrazin, D.

    1985-05-01

    Surgery is the most effective treatment for thyroid cancer; however, in some subsets of patients, the role of radiotherapy (RT) is important. The main indication for external-beam RT is incomplete surgery. When neoplastic tissue is left behind at surgery, RT must be considered, but only if an experienced surgeon feels that everything that can be done has been done. Generally, in those patients, the neoplastic tissue involves the larynx, trachea, esophagus, blood vessels or mediastinum. Of 539 patients with differentiated thyroid cancer treated at Villejuif, France, until 1976, 97 were treated by external radiotherapy after an incomplete surgical excision. Fifteen years after irradiation, the survival rate is 57% and is approximately 40% at 25 years. The relapse-free survival is lower (39% at 15 years). In patients irradiated with an adequate dose (greater than or equal to 50 Gy) to residual neoplastic tissue after incomplete surgery, the incidence of local recurrence is low (actuarial probability of local recurrence 11% at 15 years versus 23% for patients treated by surgery alone, although the irradiated patients had larger and more extensive tumors). This demonstrates the efficacy of external-beam radiotherapy. The effects of radiotherapy on a residual tumor can be monitored by a serum thyroglobulin assay. With regard to local control of tumors, the effectiveness of radioiodine administration is clearly lower. However, since radioiodine facilitates early detection of distant metastases, a combination of external RT and radioiodine is indicated and is well-tolerated.

  5. Radiotherapy T1 glottic carcinoma

    SciTech Connect

    Zablow, A.I.; Erba, P.S.; Sanfillippo, L.J.

    1989-11-01

    From 1970 to 1985, curative radiotherapy was administered to 63 patients with stage I carcinoma of the true vocal cords. Precision radiotherapeutic technique yields cure rates comparable to surgical results. Good voice quality was preserved in a high percentage of patients.

  6. Monte Carlo calculation based on hydrogen composition of the tissue for MV photon radiotherapy.

    PubMed

    Demol, Benjamin; Viard, Romain; Reynaert, Nick

    2015-09-01

    The purpose of this study was to demonstrate that Monte Carlo treatment planning systems require tissue characterization (density and composition) as a function of CT number. A discrete set of tissue classes with a specific composition is introduced. In the current work we demonstrate that, for megavoltage photon radiotherapy, only the hydrogen content of the different tissues is of interest. This conclusion might have an impact on MRI-based dose calculations and on MVCT calibration using tissue substitutes. A stoichiometric calibration was performed, grouping tissues with similar atomic composition into 15 dosimetrically equivalent subsets. To demonstrate the importance of hydrogen, a new scheme was derived, with correct hydrogen content, complemented by oxygen (all elements differing from hydrogen are replaced by oxygen). Mass attenuation coefficients and mass stopping powers for this scheme were calculated and compared to the original scheme. Twenty-five CyberKnife treatment plans were recalculated by an in-house developed Monte Carlo system using tissue density and hydrogen content derived from the CT images. The results were compared to Monte Carlo simulations using the original stoichiometric calibration. Between 300 keV and 3 MeV, the relative difference of mass attenuation coefficients is under 1% within all subsets. Between 10 keV and 20 MeV, the relative difference of mass stopping powers goes up to 5% in hard bone and remains below 2% for all other tissue subsets. Dose-volume histograms (DVHs) of the treatment plans present no visual difference between the two schemes. Relative differences of dose indexes D98, D95, D50, D05, D02, and Dmean were analyzed and a distribution centered around zero and of standard deviation below 2% (3σ) was established. On the other hand, once the hydrogen content is slightly modified, important dose differences are obtained. Monte Carlo dose planning in the field of megavoltage photon radiotherapy is fully achievable using

  7. Monte Carlo calculation based on hydrogen composition of the tissue for MV photon radiotherapy.

    PubMed

    Demol, Benjamin; Viard, Romain; Reynaert, Nick

    2015-09-08

    The purpose of this study was to demonstrate that Monte Carlo treatment planning systems require tissue characterization (density and composition) as a function of CT number. A discrete set of tissue classes with a specific composition is introduced. In the current work we demonstrate that, for megavoltage photon radiotherapy, only the hydrogen content of the different tissues is of interest. This conclusion might have an impact on MRI-based dose calculations and on MVCT calibration using tissue substitutes. A stoichiometric calibration was performed, grouping tissues with similar atomic composition into 15 dosimetrically equivalent subsets. To demonstrate the importance of hydrogen, a new scheme was derived, with correct hydrogen content, complemented by oxygen (all elements differing from hydrogen are replaced by oxygen). Mass attenuation coefficients and mass stopping powers for this scheme were calculated and compared to the original scheme. Twenty-five CyberKnife treatment plans were recalculated by an in-house developed Monte Carlo system using tissue density and hydrogen content derived from the CT images. The results were compared to Monte Carlo simulations using the original stoichiometric calibration. Between 300 keV and 3 MeV, the relative difference of mass attenuation coefficients is under 1% within all subsets. Between 10 keV and 20 MeV, the relative difference of mass stopping powers goes up to 5% in hard bone and remains below 2% for all other tissue subsets. Dose-volume histograms (DVHs) of the treatment plans present no visual difference between the two schemes. Relative differences of dose indexes D98, D95, D50, D05, D02, and Dmean were analyzed and a distribution centered around zero and of standard deviation below 2% (3 σ) was established. On the other hand, once the hydrogen content is slightly modified, important dose differences are obtained. Monte Carlo dose planning in the field of megavoltage photon radiotherapy is fully achievable using

  8. 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

  9. Treatment plan comparison between stereotactic body radiation therapy techniques for prostate cancer: non-isocentric CyberKnife versus isocentric RapidArc.

    PubMed

    Lin, Yu-Wei; Lin, Kuei-Hua; Ho, Hsiu-Wen; Lin, Hsiu-Man; Lin, Li-Ching; Lee, Steve P; Chui, Chen-Shou

    2014-09-01

    The aim of this study was to evaluate the feasibility and dose distribution of two different stereotactic body radiation therapy (SBRT) techniques, isocentric RapidArc (RA) and non-isocentric CyberKnife (CK), for the treatment of localized prostate cancer. Two groups of patients (Groups 1 and 2 with ten patients per group) treated with CK were re-planned with RA. The patients were grouped according to the rectum constraint used (Group1, maximum dose for rectum; Group 2, dose-volume histogram for rectum). The prescription dose was 37.5 Gy in five fractions. The two SBRT techniques were compared by target coverage, normal tissue sparing, and dose distribution parameters. Monitor units (MUs) and the delivery time were likewise compared to assess delivery efficiency. The RA plans consistently exhibited superior PTV coverage and better rectum sparing at low doses in the both groups. The conformity and heterogeneity indices of the RA plans were better than the CK plans. Additionally, the RA plans resulted in fewer low-dose regions, lower MUs, and faster delivery times than the CK plans. The good dosimetric distribution and shorter delivery time make RA an attractive SBRT technique for the treatment of localized prostate cancer. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  10. 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

  11. CyberKnife stereotactic radiosurgery for the treatment of symptomatic vertebral hemangiomas: a single-institution experience.

    PubMed

    Zhang, Michael; Chen, Yi-Ren; Chang, Steven D; Veeravagu, Anand

    2017-01-01

    OBJECTIVE Symptomatic vertebral hemangiomas (SVHs) are a very rare pathology that can present with persistent pain or neurological deficits that warrant surgical intervention. Given the relative rarity and difficulty in assessment, the authors sought to present a dedicated series of SVHs treated using stereotactic radiosurgery (SRS) to provide insight into clinical decision making. METHODS A retrospective review of a single institution's experience with hypofractionated radiosurgery for SVH from 2004 to 2011 was conducted to determine the clinical and radiographic outcomes following SRS treatment. The authors report and analyze the treatment course of 5 patients with 7 lesions, 2 of which were treated primarily by SRS. RESULTS Of the 5 patients studied, 4 presented with a chief complaint of pain refractory to conservative measures. Three patients reported dysesthesias, and 2 reported upper-extremity weakness. Following radiosurgery, 4 of 5 patients exhibited improvement in their primary symptoms (3 for pain and 1 for weakness), achieving a clinical response after a mean period of 1 year. In 2 cases there was 20%-40% reduction in lesion size in the most responsive dimension as noted on images. All treatments were well tolerated. CONCLUSIONS SRS for SVH is a safe and feasible treatment strategy, comparable to prior radiotherapy studies, and in select cases may successfully confer delayed decompressive effects. Additional investigation will determine future patient selection and how conformal SRS treatment can best be administered.

  12. Radiotherapy capacity in European countries: an analysis of the Directory of Radiotherapy Centres (DIRAC) database.

    PubMed

    Rosenblatt, Eduardo; Izewska, Joanna; Anacak, Yavuz; Pynda, Yaroslav; Scalliet, Pierre; Boniol, Mathieu; Autier, Philippe

    2013-02-01

    Radiotherapy is used for cure or palliation in around half of patients with cancer. We analysed data on radiotherapy equipment in 33 European countries registered in the Directory of Radiotherapy Centres (DIRAC) database, managed by the International Atomic Energy Agency. As of July, 2012, Europe had 1286 active radiotherapy centres. The average number of teletherapy machines per radiotherapy centre ranged from 1·2 to 7·0 in different countries. Nordic countries, the UK, the Netherlands, and Slovenia all have large centres with four to ten teletherapy machines. Most western and southern European countries have several small centres with one or two machines, with few larger centres. The fragmentation in radiotherapy services that prevails in many European countries might affect the economic burden of radiotherapy and its quality. Eastern and southeastern European countries need to expand and modernise their radiotherapy equipment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. SU-E-T-460: Isoeffective Dose Display (EQD2) for Composite Plan of Radiosurgery and Conventional 3D Radiotherapy.

    PubMed

    Zheng, Y; Yuan, J; Woods, C; Machtay, M; Wessels, B

    2012-06-01

    Direct addition of doses between plans with different fractionation fails to provide accurate dose-response information to anticipate clinical outcome. To combine different fractionation patterns, first-order biological model correction for dose-rate must be included. Moreover, 3-D isoeffect patterns of the combined doses must be displayed so that overlap area to elegant volumes can be avoided. The linear quadratic (LQ) model and biologically effective dose (BED) method were used to produce a combined plan in equivalent 2 Gy fractions (EQD2) for radiosurgery and conventional 3D radiotherapy. For patients with multiple courses of radiotherapy, dose distributions of the prior and boost treatment plans were converted to BED. The fraction size specified by the prescription was applied globally for each BED calculation, α/β ratio of 10 and 2.5 was used for early and late effect, respectively. Image registration with CT or MR was performed for initial and boost plans. The registration information was applied to dose distributions to obtain the composite EQD2. As a demonstration of this method, two patients were selected who had combined treatments from substantially different modalities. A patient with liver cancer initially received radiotherapy of 30 Gy/10 Fx and re-irradiation with CyberKnife radiosurgery (15 Gy/1 Fx). The combined plan showed that the PTV received EQD2 of 63.8 Gy. Another patient had brain metastasis treated with GammaKnife of 18 Gy (50% isodose) followed by conventional 3D whole brain radiation of 30 Gy/10 Fx. The minimal combined tumor EQD2 was 74.5 Gy. Early and late calculated responses showed that all critical organ doses were within tolerance. For patients receiving radiation with different fractionation schemes, combined isoeffective dose distributions were calculated and displayed. In both cases, crucial information regarding 3-D dose distributions assisted the physicians in determining whether tolerance limits of overlap areas of retreated

  14. [Quality radiotherapy in rectal cancer].

    PubMed

    Capirci, C; Amichetti, M; De Renzis, C

    2001-01-01

    The quality of radiotherapy significantly impacts on the results of treatment, in patients with rectal carcinoma, especially in terms of acute and late toxicity. Based on this assumption, the Italian Association of Radiation Oncology (AIRO) formulated a document aimed to define the standards of radiation treatment for rectal carcinomas. Two different levels of standard were described: a first level, considered as "minimal requirement", and a second level, considered as "optimal treatment". A retrospective evaluation, based on a questionnaire, revealed that in 1996, in most Italian Centers, patients affected by rectal carcinoma received radiation treatment within the first level of proposed standards. A subsequent analysis concerned the evaluation of the level of treatments applied in 2000. In this paper the radiotherapy standards proposed by the AIRO are described in the different phases of the radiation treatment.

  15. Intraoperative radiotherapy for breast cancer

    PubMed Central

    Williams, Norman R.; Pigott, Katharine H.; Brew-Graves, Chris

    2014-01-01

    Intra-operative radiotherapy (IORT) as a treatment for breast cancer is a relatively new technique that is designed to be a replacement for whole breast external beam radiotherapy (EBRT) in selected women suitable for breast-conserving therapy. This article reviews twelve reasons for the use of the technique, with a particular emphasis on targeted intra-operative radiotherapy (TARGIT) which uses X-rays generated from a portable device within the operating theatre immediately after the breast tumour (and surrounding margin of healthy tissue) has been removed. The delivery of a single fraction of radiotherapy directly to the tumour bed at the time of surgery, with the capability of adding EBRT at a later date if required (risk-adaptive technique) is discussed in light of recent results from a large multinational randomised controlled trial comparing TARGIT with EBRT. The technique avoids irradiation of normal tissues such as skin, heart, lungs, ribs and spine, and has been shown to improve cosmetic outcome when compared with EBRT. Beneficial aspects to both institutional and societal economics are discussed, together with evidence demonstrating excellent patient satisfaction and quality of life. There is a discussion of the published evidence regarding the use of IORT twice in the same breast (for new primary cancers) and in patients who would never be considered for EBRT because of their special circumstances (such as the frail, the elderly, or those with collagen vascular disease). Finally, there is a discussion of the role of the TARGIT Academy in developing and sustaining high standards in the use of the technique. PMID:25083504

  16. [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.

  17. Adjuvant and Definitive Radiotherapy for Adrenocortical Carcinoma

    SciTech Connect

    Sabolch, Aaron; Feng, Mary; Griffith, Kent; Hammer, Gary; Doherty, Gerard; Ben-Josef, Edgar

    2011-08-01

    Purpose: To evaluate the impact of both adjuvant and definitive radiotherapy on local control of adrenocortical carcinoma. Methods and Materials: Outcomes were analyzed from 58 patients with 64 instances of treatment for adrenocortical carcinoma at the University of Michigan's Multidisciplinary Adrenal Cancer Clinic. Thirty-seven of these instances were for primary disease, whereas the remaining 27 were for recurrent disease. Thirty-eight of the treatment regimens involved surgery alone, 10 surgery plus adjuvant radiotherapy, and 16 definitive radiotherapy for unresectable disease. The effects of patient, tumor, and treatment factors were modeled simultaneously using multiple variable Cox proportional hazards regression for associations with local recurrence, distant recurrence, and overall survival. Results: Local failure occurred in 16 of the 38 instances that involved surgery alone, in 2 of the 10 that consisted of surgery plus adjuvant radiotherapy, and in 1 instance of definitive radiotherapy. Lack of radiotherapy use was associated with 4.7 times the risk of local failure compared with treatment regimens that involved radiotherapy (95% confidence interval, 1.2-19.0; p = 0.030). Conclusions: Radiotherapy seems to significantly lower the risk of local recurrence/progression in patients with adrenocortical carcinoma. Adjuvant radiotherapy should be strongly considered after surgical resection.

  18. A comparative study of small field total scatter factors and dose profiles using plastic scintillation detectors and other stereotactic dosimeters: The case of the CyberKnife

    SciTech Connect

    Morin, J.; Beliveau-Nadeau, D.; Chung, E.; Seuntjens, J.; Theriault, D.; Archambault, L.; Beddar, S.; Beaulieu, L.

    2013-01-15

    Purpose: Small-field dosimetry is challenging, and the main limitations of most dosimeters are insufficient spatial resolution, water nonequivalence, and energy dependence. The purpose of this study was to compare plastic scintillation detectors (PSDs) to several commercial stereotactic dosimeters by measuring total scatter factors and dose profiles on a CyberKnife system. Methods: Two PSDs were developed, having sensitive volumes of 0.196 and 0.785 mm{sup 3}, and compared with other detectors. The spectral discrimination method was applied to subtract Cerenkov light from the signal. Both PSDs were compared to four commercial stereotactic dosimeters by measuring total scatter factors, namely, an IBA dosimetry stereotactic field diode (SFD), a PTW 60008 silicon diode, a PTW 60012 silicon diode, and a microLion. The measured total scatter factors were further compared with those of two independent Monte Carlo studies. For the dose profiles, two commercial detectors were used for the comparison, i.e., a PTW 60012 silicon diode and Gafchromics EBT2. Total scatter factors for a CyberKnife system were measured in circular fields with diameters from 5 to 60 mm. Dose profiles were measured for the 5- and 60-mm cones. The measurements were performed in a water tank at a 1.5-cm depth and an 80-cm source-axis distance. Results: The total scatter factors measured using all the detectors agreed within 1% with the Monte Carlo values for cones of 20 mm or greater in diameter. For cones of 10-20 mm in diameter, the PTW 60008 silicon diode was the only dosimeter whose measurements did not agree within 1% with the Monte Carlo values. For smaller fields (<10 mm), each dosimeter type showed different behaviors. The silicon diodes over-responded because of their water nonequivalence; the microLion and 1.0-mm PSD under-responded because of a volume-averaging effect; and the 0.5-mm PSD was the only detector within the uncertainties of the Monte Carlo simulations for all the cones. The

  19. Definitive Treatment of Early-Stage Non-Small Cell Lung Cancer with Stereotactic Ablative Body Radiotherapy in a Community Cancer Center Setting.

    PubMed

    Heal, Cory; Ding, William; Lamond, John; Wong, Michael; Lanciano, Rachelle; Su, Stacy; Yang, Jun; Feng, Jing; Arrigo, Stephen; Markiewicz, Deborah; Hanlon, Alexandra; Brady, Luther

    2015-01-01

    Stereotactic ablative body radiotherapy (SABR) provides a superior non-small cell lung cancer (NSCLC) treatment option when compared to conventional radiotherapy for patients deemed inoperable or refusing surgery. This study retrospectively analyzed the rates of tumor control and toxicity following SABR treatment (Cyberknife system) of primary early-stage NSCLC in a community setting. One hundred patients were treated between 2007 and 2011. Patients with T3-4 or N1-3 disease, metastasis, recurrent local disease, or a non-lung primary were excluded from analysis. All patients had biopsy proven disease. Staging included CT or fluorodeoxyglucose-positron emission tomography scan. Median dose was 54 Gy (45-60); 18 Gy (10-20) per fraction. Median planned target volume expansion was 8 mm (2-10). Median BED was 151.2. Tumors were tracked via Synchrony, X-Sight Lung, or X-Sight Spine. Patients were evaluated for local control, overall survival (OS), and toxicity. All local failures were determined by evaluating post treatment PET/CT. With a median follow up of 27.5 months, the 1-, 2-, and 3-year local control rates were 100, 93.55, and 84.33%, respectively. Median survival was 2.29 years; actuarial 3-year survival was 37.20%. Grade-3 toxicity was observed in 2% of patients (pneumonia within 2 months of treatment, n = 1; chronic pneumonitis requiring hospital admission, n = 1). No patients demonstrated toxicity above Grade-3. Multivariate analysis did not show T-stage as an independent predictor of OS, though it did trend toward significance. In a community-center setting, definitive treatment of NSCLC with SABR for non-surgical candidates and those who choose to forego surgery result in excellent and comparable rates of local control and toxicity compared to published series from large academic centers.

  20. Quality assurance for a multicenter Phase II study of stereotactic ablative radiotherapy for hepatocellular carcinoma ≤5 cm: a planning dummy run.

    PubMed

    Bae, Sun Hyun; Kim, Mi-Sook; Jang, Won Il; Kim, Kum Bae; Cho, Kwang Hwan; Kim, Woo Chul; Lee, Chang Yeol; Kim, Eun Seog; Choi, Chul Won; Chang, A Ram; Jo, Sunmi; Kim, Jin-Young

    2017-06-01

    The Korean Radiation Oncology Group (12-02) investigated the outcome of stereotactic ablative radiotherapy for hepatocellular carcinoma ≤5 cm using 60 Gy in three fractions. To evaluate dosimetric differences and compliance in a multicenter trial, a planning dummy run procedure was performed. All six participating institutions were provided the contours of two dummy run cases. Plans were performed following the study protocol to cover the planning target volume with a minimum of 90% of the prescription dose and to satisfy the constraints for organs at risk. We assessed the institutional variations in plans using dose-volume histograms. Different planning techniques were applied: static intensity-modulated radiotherapy in two institutions, CyberKnife in two institutions and RapidArc in two institutions. The conformity index of all 12 plans was ≤1.2. In terms of the planning target volume coverage, all participants followed our study protocol. For the second dummy run case, located in Segment 8 near the heart, the minimum dose of the planning target volume (D99%: dose covering 99% of the planning target volume) was variable because there was no mention of constraints of D99% of the planning target volume in the study protocol. As an important organ at risk, the normal liver volumes receiving <17 Gy in all 12 plans were >700 ml. Dosimetric parameters showed acceptable compliance with the study protocol. However, we found the possibility of underdose to the planning target volume if the hepatocellular carcinoma lesion was located near organs at risk such as the heart. Based on this dummy run, we will conduct individual case reviews to minimize the effects of study protocol deviation.

  1. Dosimetric properties of radiophotoluminescent glass rod detector in high-energy photon beams from a linear accelerator and cyber-knife.

    PubMed

    Arakia, Fujio; Moribe, Nobuyuki; Shimonobou, Toshiaki; Yamashita, Yasuyuki

    2004-07-01

    A fully automatic radiophotoluminescent glass rod dosimeter (GRD) system has recently become commercially available. This article discusses the dosimetric properties of the GRD including uniformity and reproducibility of signal, dose linearity, and energy and directional dependence in high-energy photon beams. In addition, energy response is measured in electron beams. The uniformity and reproducibility of the signal from 50 GRDs using a 60Co beam are both +/- 1.1% (one standard deviation). Good dose linearity of the GRD is maintained for doses ranging from 0.5 to 30 Gy, the lower and upper limits of this study, respectively. The GRD response is found to show little energy dependence in photon energies of a 60Co beam, 4 MV (TPR20(10)=0.617) and 10 MV (TPR(20)10=0.744) x-ray beams. However, the GRD responses for 9 MeV (mean energy, Ez = 3.6 MeV) and 16 MeV (Ez = 10.4 MeV) electron beams are 4%-5% lower than that for a 60Co beam in the beam quality dependence. The measured angular dependence of GRD, ranging from 0 degrees (along the long axis of GRD) to 120 degrees is within 1.5% for a 4 MV x-ray beam. As applications, a linear accelerator-based radiosurgery system and Cyber-Knife output factors are measured by a GRD and compared with those from various detectors including a p-type silicon diode detector, a diamond detector, and an ion chamber. It is found that the GRD is a very useful detector for small field dosimetry, in particular, below 10 mm circular fields.

  2. Plan delivery quality assurance for CyberKnife: Statistical process control analysis of 350 film-based patient-specific QAs.

    PubMed

    Bellec, J; Delaby, N; Jouyaux, F; Perdrieux, M; Bouvier, J; Sorel, S; Henry, O; Lafond, C

    2017-07-01

    Robotic radiosurgery requires plan delivery quality assurance (DQA) but there has never been a published comprehensive analysis of a patient-specific DQA process in a clinic. We proposed to evaluate 350 consecutive film-based patient-specific DQAs using statistical process control. We evaluated the performance of the process to propose achievable tolerance criteria for DQA validation and we sought to identify suboptimal DQA using control charts. DQAs were performed on a CyberKnife-M6 using Gafchromic-EBT3 films. The signal-to-dose conversion was performed using a multichannel-correction and a scanning protocol that combined measurement and calibration in a single scan. The DQA analysis comprised a gamma-index analysis at 3%/1.5mm and a separate evaluation of spatial and dosimetric accuracy of the plan delivery. Each parameter was plotted on a control chart and control limits were calculated. A capability index (Cpm) was calculated to evaluate the ability of the process to produce results within specifications. The analysis of capability showed that a gamma pass rate of 85% at 3%/1.5mm was highly achievable as acceptance criteria for DQA validation using a film-based protocol (Cpm>1.33). 3.4% of DQA were outside a control limit of 88% for gamma pass-rate. The analysis of the out-of-control DQA helped identify a dosimetric error in our institute for a specific treatment type. We have defined initial tolerance criteria for DQA validations. We have shown that the implementation of a film-based patient-specific DQA protocol with the use of control charts is an effective method to improve patient treatment safety on CyberKnife. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  3. Sci—Sat AM: Stereo — 07: Suitability of a plastic scintillator dosimeter for composite clinical fields delivered using the Cyberknife robotic radiosurgery system

    SciTech Connect

    Vandervoort, E.; Szanto, J.; Christiansen, E.

    2014-08-15

    Plastic scintillation dosimeters (PSDs) have favourable characteristics for small and composite field dosimetry in radiosurgery, however, imperfect corrections for the Cerenkov radiation contamination could limit their accuracy for complex deliveries. In this work, we characterize the dose and dose-rate linearity, directional dependence, and compare output factors with other stereotactic detectors for a new commercially available PSD (Exradin W1). We provide some preliminary comparisons of planned and measured dose for composite fields delivered clinically by a Cyberknife radiosurgery system. The W1 detector shows good linearity with dose (<0.5%) and dose rate (<0.8%) relative to the signal obtained using an ion chamber under the same conditions. A maximum difference of 2% was observed depending on the detector's angular orientation. Output factors for all detectors agree within a range of ±3.2% and ±1.5% for the 5 and 7.5 mm collimators, respectively, provided Monte-Carlo corrections for detector effects are applied to diode and ion chambers (without corrections the range is ±5.5% and ±3.1% for these two collimators). For clinical beam deliveries using 5 and 7.5 mm collimators, four of the six patients showed better agreement with planned dose for the PSD detector compared to a micro ion chamber. Two of the six patients investigated, however, showed 5% differences between PSD and planned dose, film measurements and the ratio of PSD and micro ion chamber signal suggest that further investigation is warranted for these plans. The W1 detector is a promising tool for stereotactic plan verification under the challenging dosimetric conditions of stereotactic radiosurgery.

  4. Dosimetric and radiobiological comparison of CyberKnife M6™ InCise multileaf collimator over IRIS™ variable collimator in prostate stereotactic body radiation therapy

    PubMed Central

    Kathriarachchi, Vindu; Shang, Charles; Evans, Grant; Leventouri, Theodora; Kalantzis, Georgios

    2016-01-01

    The impetus behind our study was to establish a quantitative comparison between the IRIS collimator and the InCise multileaf collimator (MLC) (Accuray Inc. Synnyvale, CA) for prostate stereotactic body radiation therapy (SBRT). Treatment plans for ten prostate cancer patients were performed on MultiPlan™ 5.1.2 treatment planning system utilizing MLC and IRIS for 36.25 Gy in five fractions. To reduce the magnitude of variations between cases, the planning tumor volume (PTV) was defined and outlined for treating prostate gland only, assuming no seminal vesicle or ex-capsule involvement. Evaluation indices of each plan include PTV coverage, conformity index (CI), Paddick's new CI, homogeneity index, and gradient index. Organ at risk (OAR) dose sparing was analyzed by the bladder wall Dmax and V37Gy, rectum Dmax and V36Gy. The radiobiological response was evaluated by tumor control probability and normal tissue complication probability based on equivalent uniform dose. The dose delivery efficiency was evaluated on the basis of planned monitor units (MUs) and the reported treatment time per fraction. Statistical significance was tested using the Wilcoxon signed rank test. The studies indicated that CyberKnife M6™ IRIS and InCise™ MLC produce equivalent SBRT prostate treatment plans in terms of dosimetry, radiobiology, and OAR sparing, except that the MLC plans offer improvement of the dose fall-off gradient by 29% over IRIS. The main advantage of replacing the IRIS collimator with MLC is the improved efficiency, determined from the reduction of MUs by 42%, and a 36% faster delivery time. PMID:27217626

  5. Dosimetric and radiobiological comparison of CyberKnife M6™ InCise multileaf collimator over IRIS™ variable collimator in prostate stereotactic body radiation therapy.

    PubMed

    Kathriarachchi, Vindu; Shang, Charles; Evans, Grant; Leventouri, Theodora; Kalantzis, Georgios

    2016-01-01

    The impetus behind our study was to establish a quantitative comparison between the IRIS collimator and the InCise multileaf collimator (MLC) (Accuray Inc. Synnyvale, CA) for prostate stereotactic body radiation therapy (SBRT). Treatment plans for ten prostate cancer patients were performed on MultiPlan™ 5.1.2 treatment planning system utilizing MLC and IRIS for 36.25 Gy in five fractions. To reduce the magnitude of variations between cases, the planning tumor volume (PTV) was defined and outlined for treating prostate gland only, assuming no seminal vesicle or ex-capsule involvement. Evaluation indices of each plan include PTV coverage, conformity index (CI), Paddick's new CI, homogeneity index, and gradient index. Organ at risk (OAR) dose sparing was analyzed by the bladder wall Dmax and V37Gy, rectum Dmax and V36Gy. The radiobiological response was evaluated by tumor control probability and normal tissue complication probability based on equivalent uniform dose. The dose delivery efficiency was evaluated on the basis of planned monitor units (MUs) and the reported treatment time per fraction. Statistical significance was tested using the Wilcoxon signed rank test. The studies indicated that CyberKnife M6™ IRIS and InCise™ MLC produce equivalent SBRT prostate treatment plans in terms of dosimetry, radiobiology, and OAR sparing, except that the MLC plans offer improvement of the dose fall-off gradient by 29% over IRIS. The main advantage of replacing the IRIS collimator with MLC is the improved efficiency, determined from the reduction of MUs by 42%, and a 36% faster delivery time.

  6. Virtual HDR CyberKnife SBRT for Localized Prostatic Carcinoma: 5-Year Disease-Free Survival and Toxicity Observations

    PubMed Central

    Fuller, Donald Blake; Naitoh, John; Mardirossian, George

    2014-01-01

    Purpose: Prostate stereotactic body radiotherapy (SBRT) may substantially recapitulate the dose distribution of high-dose-rate (HDR) brachytherapy, representing an externally delivered “Virtual HDR” treatment method. Herein, we present 5-year outcomes from a cohort of consecutively treated virtual HDR SBRT prostate cancer patients. Methods: Seventy-nine patients were treated from 2006 to 2009, 40 low-risk, and 39 intermediate-risk, under IRB-approved clinical trial, to 38 Gy in four fractions. The planning target volume (PTV) included prostate plus a 2-mm volume expansion in all directions, with selective use of a 5-mm prostate-to-PTV expansion and proximal seminal vesicle coverage in intermediate-risk patients, to better cover potential extraprostatic disease; rectal PTV margin reduced to zero in all cases. The prescription dose covered >95% of the PTV (V100 ≥95%), with a minimum 150% PTV dose escalation to create “HDR-like” PTV dose distribution. Results: Median pre-SBRT PSA level of 5.6 ng/mL decreased to 0.05 ng/mL 5 years out and 0.02 ng/mL 6 years out. At least one PSA bounce was seen in 55 patients (70%) but only 3 of them subsequently relapsed, biochemical-relapse-free survival was 100 and 92% for low-risk and intermediate-risk patients, respectively, by ASTRO definition (98 and 92% by Phoenix definition). Local relapse did not occur, distant metastasis-free survival was 100 and 95% by risk-group, and disease-specific survival was 100%. Acute and late grade 2 GU toxicity incidence was 10 and 9%, respectively; with 6% late grade 3 GU toxicity. Acute urinary retention did not occur. Acute and late grade 2 GI toxicity was 0 and 1%, respectively, with no grade 3 or higher toxicity. Of patient’s potent pre-SBRT, 65% remained so at 5 years. Conclusion: Virtual HDR prostate SBRT creates a very low PSA nadir, a high rate of 5-year disease-free survival and an acceptable toxicity incidence, with results closely resembling those reported

  7. Virtual HDR CyberKnife SBRT for Localized Prostatic Carcinoma: 5-Year Disease-Free Survival and Toxicity Observations.

    PubMed

    Fuller, Donald Blake; Naitoh, John; Mardirossian, George

    2014-01-01

    Prostate stereotactic body radiotherapy (SBRT) may substantially recapitulate the dose distribution of high-dose-rate (HDR) brachytherapy, representing an externally delivered "Virtual HDR" treatment method. Herein, we present 5-year outcomes from a cohort of consecutively treated virtual HDR SBRT prostate cancer patients. Seventy-nine patients were treated from 2006 to 2009, 40 low-risk, and 39 intermediate-risk, under IRB-approved clinical trial, to 38 Gy in four fractions. The planning target volume (PTV) included prostate plus a 2-mm volume expansion in all directions, with selective use of a 5-mm prostate-to-PTV expansion and proximal seminal vesicle coverage in intermediate-risk patients, to better cover potential extraprostatic disease; rectal PTV margin reduced to zero in all cases. The prescription dose covered >95% of the PTV (V100 ≥95%), with a minimum 150% PTV dose escalation to create "HDR-like" PTV dose distribution. Median pre-SBRT PSA level of 5.6 ng/mL decreased to 0.05 ng/mL 5 years out and 0.02 ng/mL 6 years out. At least one PSA bounce was seen in 55 patients (70%) but only 3 of them subsequently relapsed, biochemical-relapse-free survival was 100 and 92% for low-risk and intermediate-risk patients, respectively, by ASTRO definition (98 and 92% by Phoenix definition). Local relapse did not occur, distant metastasis-free survival was 100 and 95% by risk-group, and disease-specific survival was 100%. Acute and late grade 2 GU toxicity incidence was 10 and 9%, respectively; with 6% late grade 3 GU toxicity. Acute urinary retention did not occur. Acute and late grade 2 GI toxicity was 0 and 1%, respectively, with no grade 3 or higher toxicity. Of patient's potent pre-SBRT, 65% remained so at 5 years. Virtual HDR prostate SBRT creates a very low PSA nadir, a high rate of 5-year disease-free survival and an acceptable toxicity incidence, with results closely resembling those reported post-HDR brachytherapy.

  8. Radiotherapy and local control in rectal cancer.

    PubMed

    Valentini, V; Rosetto, M E; Fares, C; Mantini, G; Salvi, G; Turriziani, A

    1998-01-01

    Recurrence is a stage in the natural history of rectal cancer. Preoperative radiotherapy or postoperative radiochemotherapy lower the rate of recurrence, improving local control. From 1980 to 1997, at the "Divisione di Radioterapia" of the "Università Cattolica del S. Cuore" of Rome 380 patients with rectal cancer of early clinical stage T2-3, candidates for surgery for cure, underwent radiation therapy. 119 patients underwent postoperative radiotherapy (45-50 Gy); 45 patients underwent "sandwich" radiotherapy (45 Gy:27 Gy before and 28 Gy after surgery), of whom 7 were treated with preoperative radiotherapy alone; 145 patients underwent preoperative concomitant radiochemotherapy according to 3 different protocols, radiotherapy (38 Gy) combined with mitomycin C and 5-FU; radiotherapy (50.4 Gy) combined with cisplatin and 5-FU; radiotherapy (45 Gy) combined with 5-FU and folinic acid. 71 patients were treated with preoperative radiotherapy (38 Gy) combined with IORT (10 Gy). Median follow-up was 6 years. Overall local control was 85% at 3 years, 83% at 5 years, 81% at 10 years. The rate of local control at 5 years was: 76% for postoperative radiotherapy, 83% for "sandwich" radiotherapy, 84% for preoperative radiochemotherapy and 93% for preoperative radiotherapy combined with IORT. Local control was shown to be significantly better with preoperative treatment as compared to postoperative treatment (p = 0.02). The incidence of metastases was 35% in the patients with local recurrence and 16% in those with local control. The difference in survival was highly significant in patients with local control as compared to those with local recurrence: at 5 years 87% and 32% respectively. Patients with local control showed a lower incidence of metastasis and a better survival.

  9. Clinical study on the influence of motion and other factors on stereotactic radiotherapy in the treatment of adrenal gland tumor

    PubMed Central

    Wang, Jingsheng; Li, Fengtong; Dong, Yang; Song, Yongchun; Yuan, Zhiyong

    2016-01-01

    Background The aim of this study was to investigate the adrenal tumor motion law and influence factors in the treatment of adrenal gland tumor and provide a reference value basis for determining the planning target volume margins for therapy. Materials and methods The subjects considered in this study were 38 adrenal tumor patients treated with CyberKnife with the placement of 45 gold fiducials. Fiducials were implanted into each adrenal tumor using β-ultrasonic guidance. Motion amplitudes of gold fiducials were measured with a Philips SLS simulator and motion data in the left–right, anterior–posterior, and cranio–caudal directions were obtained. Multiple linear regression models were used to analyze influencing factors. t-Test was used for motion amplitude comparison of different tumor locations along the z-axis. Results The motion distances were 0.1–0.4 cm (0.27±0.07 cm), 0.1–0.5 cm (0.31±0.11 cm), and 0.5–1.2 cm (0.87±0.21 cm) along the x-, y-, and z-axes, respectively. Motion amplitude along the z-axis may be affected by tumor location, but movement along the other axes was not affected by age, height, body mass, location, and size. Conclusion The maximum motion distance was along the z-axis. Therefore, this should be the main consideration when defining the planning target volume safety margin. Due to the proximity of the liver, adrenal gland tumor motion amplitude was smaller on the right than the left. This study analyzed adrenal tumor motion amplitude data to evaluate how motion and other factors influence the treatment of adrenal tumor with a goal of providing a reference for stereotactic radiotherapy boundary determination. PMID:27486331

  10. 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.

  11. SU-E-T-545: A MLC-Equipped Robotic Radiosurgery-Radiotherapy Combined System in Treating Hepatic Lesions: Delivery Efficiency as Compared to a Standard Linac for Treating Hepatic Lesions

    SciTech Connect

    Jin, L; Price, R; Wang, L; Meyer, J; Ma, C; Fan, J

    2014-06-01

    Purpose: The CyberKnife (CK) M6 Series introduced a mulitleaf collimator (MLC) beam for extending its capability to the conventional radiotherapy. This work is to investigate delivery efficiency of this system as compared to a standard Varian linac when treating hepatic lesions. Methods: Nine previously treated patients were divided into three groups with three patients in each. Group one: fractionated radiotherapy; Group two: SBRT-like treatments and Group three: fractionated radiotherapy targeting two PTVs. The clinically used plans were generated with the Eclipse treatment planning system (TPS). We re-planned these cases using a Mulitplan (MP) TPS for the CK M6 and normalized to the same PTV dose coverage. CK factors (CF) (defined as modulation scaling factor in this work), number of nodes (NN), number of MLC segments (NS) and beam delivery time (BT) with an estimated image interval of 60 seconds, were used for evaluation of delivery efficiency. Results: Generated plans from the MP and Eclipse TPS demonstrated the similar quality in terms of PTV confomality index, minimum and maximum PTV doses, and doses received by critical structures. Group one: CF ranged from 8.1 to 8.7, NN from 30 to 40, NS from 120 to 155 and BT from 20 to 23 minutes; group two: CF from 4.7 to 8.5, NN from 15 to 19, NS from 82 to 141 and BT from 18 to 24 minutes; and group three: CF from 7.9 to 10, NN from 47 to 49, NS from 110 to 113 and BT from 20 to 22 minutes. Conclusions: Delivery time is longer for the CK M6 than for the Varian linac (7.8 to 13.7 minutes). Further investigation will be necessary to determine if a PTV reduction from the tracking feature will shorten the delivery time without decreasing plan quality.

  12. [MRI-based radiotherapy planning].

    PubMed

    Largent, A; Nunes, J-C; Lafond, C; Périchon, N; Castelli, J; Rolland, Y; Acosta, O; de Crevoisier, R

    2017-07-06

    MRI-based radiotherapy planning is a topical subject due to the introduction of a new generation of treatment machines combining a linear accelerator and a MRI. One of the issues for introducing MRI in this task is the lack of information to provide tissue density information required for dose calculation. To cope with this issue, two strategies may be distinguished from the literature. Either a synthetic CT scan is generated from the MRI to plan the dose, or a dose is generated from the MRI based on physical underpinnings. Within the first group, three approaches appear: bulk density mapping assign a homogeneous density to different volumes of interest manually defined on a patient MRI; machine learning-based approaches model local relationship between CT and MRI image intensities from multiple data, then applying the model to a new MRI; atlas-based approaches use a co-registered training data set (CT-MRI) which are registered to a new MRI to create a pseudo CT from spatial correspondences in a final fusion step. Within the second group, physics-based approaches aim at computing the dose directly from the hydrogen contained within the tissues, quantified by MRI. Excepting the physics approach, all these methods generate a synthetic CT called "pseudo CT", on which radiotherapy planning will be finally realized. This literature review shows that atlas- and machine learning-based approaches appear more accurate dosimetrically. Bulk density approaches are not appropriate for bone localization. The fastest methods are machine learning and the slowest are atlas-based approaches. The less automatized are bulk density assignation methods. The physical approaches appear very promising methods. Finally, the validation of these methods is crucial for a clinical practice, in particular in the perspective of adaptive radiotherapy delivered by a linear accelerator combined with an MRI scanner. Copyright © 2017. Published by Elsevier SAS.

  13. Radiotherapy in patients with connective tissue diseases.

    PubMed

    Giaj-Levra, Niccolò; Sciascia, Savino; Fiorentino, Alba; Fersino, Sergio; Mazzola, Rosario; Ricchetti, Francesco; Roccatello, Dario; Alongi, Filippo

    2016-03-01

    The decision to offer radiotherapy in patients with connective tissue diseases continues to be challenging. Radiotherapy might trigger the onset of connective tissue diseases by increasing the expression of self-antigens, diminishing regulatory T-cell activity, and activating effectors of innate immunity (dendritic cells) through Toll-like receptor-dependent mechanisms, all of which could potentially lead to breaks of immune tolerance. This potential risk has raised some debate among radiation oncologists about whether patients with connective tissue diseases can tolerate radiation as well as people without connective tissue diseases. Because the number of patients with cancer and connective tissue diseases needing radiotherapy will probably increase due to improvements in medical treatment and longer life expectancy, the issue of interactions between radiotherapy and connective tissue diseases needs to be clearer. In this Review, we discuss available data and evidence for patients with connective tissue diseases treated with radiotherapy.

  14. Ion-induced nuclear radiotherapy

    DOEpatents

    Horn, Kevin M.; Doyle, Barney L.

    1996-01-01

    Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue.

  15. Stereotactic body radiotherapy for oligometastases.

    PubMed

    Tree, Alison C; Khoo, Vincent S; Eeles, Rosalind A; Ahmed, Merina; Dearnaley, David P; Hawkins, Maria A; Huddart, Robert A; Nutting, Christopher M; Ostler, Peter J; van As, Nicholas J

    2013-01-01

    The management of metastatic solid tumours has historically focused on systemic treatment given with palliative intent. However, radical surgical treatment of oligometastases is now common practice in some settings. The development of stereotactic body radiotherapy (SBRT), building on improvements in delivery achieved by intensity-modulated and image-guided radiotherapy, now allows delivery of ablative doses of radiation to extracranial sites. Many non-randomised studies have shown that SBRT for oligometastases is safe and effective, with local control rates of about 80%. Importantly, these studies also suggest that the natural history of the disease is changing, with 2-5 year progression-free survival of about 20%. Although complete cure might be possible in a few patients with oligometastases, the aim of SBRT in this setting is to achieve local control and delay progression, and thereby also postpone the need for further treatment. We review published work showing that SBRT offers durable local control and the potential for progression-free survival in non-liver, non-lung oligometastatic disease at a range of sites. However, to test whether SBRT really does improve progression-free survival, randomised trials will be essential. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Ion-induced nuclear radiotherapy

    DOEpatents

    Horn, K.M.; Doyle, B.L.

    1996-08-20

    Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue. 25 figs.

  17. Improving postoperative radiotherapy following radical prostatectomy.

    PubMed

    Lipman, D; Pieters, B R; De Reijke, Theo M

    2017-10-01

    Prostate cancer has one of the highest incidences in the world, with good curative treatment options like radiotherapy and radical prostatectomy. Unfortunately, about 30% of the patients initially treated with curative intent will develop a recurrence and need adjuvant treatment. Five randomized trials covered the role of postoperative radiotherapy after radical prostatectomy, but there is still a lot of debate about which patients should receive postoperative radiotherapy. Areas covered: This review will give an overview on the available literature concerning post-operative radiotherapy following radical prostatectomy with an emphasis on the five randomized trials. Also, new imaging techniques like prostate-specific membrane antigen positron emission tomography (PSMA-PET) and multiparametric magnetic resonance imaging (mp-MRI) and the development of biomarkers like genomic classifiers will be discussed in the search for an improved selection of patients who will benefit from postoperative radiotherapy following radical prostatectomy. With new treatment techniques like Intensity Modulated Radiotherapy, toxicity profiles will be kept low. Expert commentary: Patients with biochemical recurrence following radical prostatectomy with an early rise in prostate-specific antigen (PSA) will benefit most from postoperative radiotherapy. In this way, patients with only high risk pathological features can avoid unnecessary treatment and toxicity, and early intervention in progressing patients would not compromise the outcome.

  18. Predictors for trismus in patients receiving radiotherapy.

    PubMed

    van der Geer, S Joyce; Kamstra, Jolanda I; Roodenburg, Jan L N; van Leeuwen, Marianne; Reintsema, Harry; Langendijk, Johannes A; Dijkstra, Pieter U

    2016-11-01

    Trismus, a restricted mouth opening in head and neck cancer patients may be caused by tumor infiltration in masticatory muscles, radiation-induced fibrosis or scarring after surgery. It may impede oral functioning severely. The aims of our study were to determine: (1) the incidence of trismus at various time points; and (2) the patient, tumor, and treatment characteristics that predict the development of trismus after radiotherapy in head and neck cancer patients using a large database (n = 641). Maximal mouth opening was measured prior to and 6, 12, 18, 24, 36, and 48 months after radiotherapy. Patient, tumor, and treatment characteristics were analyzed as potential predictors for trismus using a multivariable logistic regression analysis. At six months after radiotherapy, 28.1% of the patients without trismus prior to radiotherapy developed trismus for the first time. At subsequent time points the incidence declined. Over a total period of 48 months after radiotherapy, the incidence of trismus was 3.6 per 10 person years at risk. Patients who had tumors located in the oral cavity, oropharynx or nasopharynx, and the salivary glands or ear, and who had a longer overall treatment time of radiotherapy, were more likely to develop trismus in the first six months after radiotherapy. Maximal mouth opening was a predictor for developing trismus at all time points. Incidence of trismus is 3.6 per 10 person years at risk. Tumor localization and overall treatment time of radiotherapy are predictors for developing trismus the first six months after radiotherapy. Maximal mouth opening is a significant predictor for developing trismus at all time points. Regular measurements of maximal mouth opening are needed to predict trismus.

  19. 4D ultrasound speckle tracking of intra-fraction prostate motion: a phantom-based comparison with x-ray fiducial tracking using CyberKnife.

    PubMed

    O'Shea, Tuathan P; Garcia, Leo J; Rosser, Karen E; Harris, Emma J; Evans, Philip M; Bamber, Jeffrey C

    2014-04-07

    This study investigates the use of a mechanically-swept 3D ultrasound (3D-US) probe for soft-tissue displacement monitoring during prostate irradiation, with emphasis on quantifying the accuracy relative to CyberKnife® x-ray fiducial tracking. An US phantom, implanted with x-ray fiducial markers was placed on a motion platform and translated in 3D using five real prostate motion traces acquired using the Calypso system. Motion traces were representative of all types of motion as classified by studying Calypso data for 22 patients. The phantom was imaged using a 3D swept linear-array probe (to mimic trans-perineal imaging) and, subsequently, the kV x-ray imaging system on CyberKnife. A 3D cross-correlation block-matching algorithm was used to track speckle in the ultrasound data. Fiducial and US data were each compared with known phantom displacement. Trans-perineal 3D-US imaging could track superior-inferior (SI) and anterior-posterior (AP) motion to ≤0.81 mm root-mean-square error (RMSE) at a 1.7 Hz volume rate. The maximum kV x-ray tracking RMSE was 0.74 mm, however the prostate motion was sampled at a significantly lower imaging rate (mean: 0.04 Hz). Initial elevational (right-left; RL) US displacement estimates showed reduced accuracy but could be improved (RMSE <2.0 mm) using a correlation threshold in the ultrasound tracking code to remove erroneous inter-volume displacement estimates. Mechanically-swept 3D-US can track the major components of intra-fraction prostate motion accurately but exhibits some limitations. The largest US RMSE was for elevational (RL) motion. For the AP and SI axes, accuracy was sub-millimetre. It may be feasible to track prostate motion in 2D only. 3D-US also has the potential to improve high tracking accuracy for all motion types. It would be advisable to use US in conjunction with a small (∼2.0 mm) centre-of-mass displacement threshold in which case it would be possible to take full advantage of the accuracy and high

  20. Analysis of volumetric response of pituitary adenomas receiving adjuvant CyberKnife stereotactic radiosurgery with the application of an exponential fitting model

    PubMed Central

    Yu, Yi-Lin; Yang, Yun-Ju; Lin, Chin; Hsieh, Chih-Chuan; Li, Chiao-Zhu; Feng, Shao-Wei; Tang, Chi-Tun; Chung, Tzu-Tsao; Ma, Hsin-I; Chen, Yuan-Hao; Ju, Da-Tong; Hueng, Dueng-Yuan

    2017-01-01

    Abstract Tumor control rates of pituitary adenomas (PAs) receiving adjuvant CyberKnife stereotactic radiosurgery (CK SRS) are high. However, there is currently no uniform way to estimate the time course of the disease. The aim of this study was to analyze the volumetric responses of PAs after CK SRS and investigate the application of an exponential decay model in calculating an accurate time course and estimation of the eventual outcome. A retrospective review of 34 patients with PAs who received adjuvant CK SRS between 2006 and 2013 was performed. Tumor volume was calculated using the planimetric method. The percent change in tumor volume and tumor volume rate of change were compared at median 4-, 10-, 20-, and 36-month intervals. Tumor responses were classified as: progression for >15% volume increase, regression for ≤15% decrease, and stabilization for ±15% of the baseline volume at the time of last follow-up. For each patient, the volumetric change versus time was fitted with an exponential model. The overall tumor control rate was 94.1% in the 36-month (range 18–87 months) follow-up period (mean volume change of −43.3%). Volume regression (mean decrease of −50.5%) was demonstrated in 27 (79%) patients, tumor stabilization (mean change of −3.7%) in 5 (15%) patients, and tumor progression (mean increase of 28.1%) in 2 (6%) patients (P = 0.001). Tumors that eventually regressed or stabilized had a temporary volume increase of 1.07% and 41.5% at 4 months after CK SRS, respectively (P = 0.017). The tumor volume estimated using the exponential fitting equation demonstrated high positive correlation with the actual volume calculated by magnetic resonance imaging (MRI) as tested by Pearson correlation coefficient (0.9). Transient progression of PAs post-CK SRS was seen in 62.5% of the patients receiving CK SRS, and it was not predictive of eventual volume regression or progression. A three-point exponential model is of potential predictive value

  1. SU-E-T-587: Monte Carlo Versus Ray-Tracing for Treatment Planning Involving CNS Tumors On the MultiPlan System for CyberKnife Radiosurgery

    SciTech Connect

    Forbang, R Teboh

    2014-06-01

    Purpose: MultiPlan, the treatment planning system for the CyberKnife Robotic Radiosurgery system offers two approaches to dose computation, namely Ray-Tracing (RT), the default technique and Monte Carlo (MC), an option. RT is deterministic, however it accounts for primary heterogeneity only. MC on the other hand has an uncertainty associated with the calculation results. The advantage is that in addition, it accounts for heterogeneity effects on the scattered dose. Not all sites will benefit from MC. The goal of this work was to focus on central nervous system (CNS) tumors and compare dosimetrically, treatment plans computed with RT versus MC. Methods: Treatment plans were computed using both RT and MC for sites covering (a) the brain (b) C-spine (c) upper T-spine (d) lower T-spine (e) L-spine and (f) sacrum. RT was first used to compute clinically valid treatment plans. Then the same treatment parameters, monitor units, beam weights, etc., were used in the MC algorithm to compute the dose distribution. The plans were then compared for tumor coverage to illustrate the difference if any. All MC calculations were performed at a 1% uncertainty. Results: Using the RT technique, the tumor coverage for the brain, C-spine (C3–C7), upper T-spine (T4–T6), lower T-spine (T10), Lspine (L2) and sacrum were 96.8%, 93.1%, 97.2%, 87.3%, 91.1%, and 95.3%. The corresponding tumor coverage based on the MC approach was 98.2%, 95.3%, 87.55%, 88.2%, 92.5%, and 95.3%. It should be noted that the acceptable planning target coverage for our clinical practice is >95%. The coverage can be compromised for spine tumors to spare normal tissues such as the spinal cord. Conclusion: For treatment planning involving the CNS, RT and MC appear to be similar for most sites but for the T-spine area where most of the beams traverse lung tissue. In this case, MC is highly recommended.

  2. SU-E-T-382: Evaluation of Clinical Application and Dosimetric Comparison for Treatment Plans of Gamma Knife and CyberKnife for Arteriovenous Malformations

    SciTech Connect

    Kuo, C

    2015-06-15

    Purpose: To analyze and compare the characteristics of dose distributions between Gamma Knife (GK) and CyberKnife (CK), in treating arteriovenous malformations (AVMs), and evaluate the influences on their clinical applications. Methods: Twenty four patients with AVMs treated with CK of prescribed dose (PD) of 16–25 Gy in single fraction were selected. Each patient’s CT images used for CK treatment planning with contours of targets and critical organs were exported and then loaded into the GK planning system. GK treatment plan with the same PD used in CK was generated for each patient. The metrics for dose comparison between GK and CK included conformity index (CI), gradient index (GI) of 75%, 50% and 25% of the PD, heterogeneity index (HI), volume of brain tissues covered by 10 Gy and 12 Gy, maximum dose to brainstem and beam-on time. Paired Samples t-test was used to analyze these metrics for significance (p value). Results: The CI were 0.744 ± 0.075 (GK) and 0.768 ± 0.086 (CK), p = 0.281. The GI75%, GI50%, and GI25% in GK and CK were 1.735 ± 0.100 and 2.439 ± 0.338 (p < 0.001), 3.169 ± 0.265 and 4.972 ± 0.852 (p < 0.001), and 8.650 ± 0.914 and 14.261 ± 2.476 (p < 0.001). The HI were 0.728 ± 0.072 (GK) and 0.313 ± 0.069 (CK), p < 0.001. There were significant differences both for volume of brain tissues covered by 10 Gy and 12 Gy in GK and CK (p < 0.001). GK had smaller maximum dose to brainstem. CK had shorter beam-on time. Conclusion: GK has similar dose conformity as CK, and has better normal tissue sparing but is less efficient than CK.

  3. 4D ultrasound speckle tracking of intra-fraction prostate motion: a phantom-based comparison with x-ray fiducial tracking using CyberKnife

    NASA Astrophysics Data System (ADS)

    O'Shea, Tuathan P.; Garcia, Leo J.; Rosser, Karen E.; Harris, Emma J.; Evans, Philip M.; Bamber, Jeffrey C.

    2014-04-01

    This study investigates the use of a mechanically-swept 3D ultrasound (3D-US) probe for soft-tissue displacement monitoring during prostate irradiation, with emphasis on quantifying the accuracy relative to CyberKnife® x-ray fiducial tracking. An US phantom, implanted with x-ray fiducial markers was placed on a motion platform and translated in 3D using five real prostate motion traces acquired using the Calypso system. Motion traces were representative of all types of motion as classified by studying Calypso data for 22 patients. The phantom was imaged using a 3D swept linear-array probe (to mimic trans-perineal imaging) and, subsequently, the kV x-ray imaging system on CyberKnife. A 3D cross-correlation block-matching algorithm was used to track speckle in the ultrasound data. Fiducial and US data were each compared with known phantom displacement. Trans-perineal 3D-US imaging could track superior-inferior (SI) and anterior-posterior (AP) motion to ≤0.81 mm root-mean-square error (RMSE) at a 1.7 Hz volume rate. The maximum kV x-ray tracking RMSE was 0.74 mm, however the prostate motion was sampled at a significantly lower imaging rate (mean: 0.04 Hz). Initial elevational (right-left RL) US displacement estimates showed reduced accuracy but could be improved (RMSE <2.0 mm) using a correlation threshold in the ultrasound tracking code to remove erroneous inter-volume displacement estimates. Mechanically-swept 3D-US can track the major components of intra-fraction prostate motion accurately but exhibits some limitations. The largest US RMSE was for elevational (RL) motion. For the AP and SI axes, accuracy was sub-millimetre. It may be feasible to track prostate motion in 2D only. 3D-US also has the potential to improve high tracking accuracy for all motion types. It would be advisable to use US in conjunction with a small (˜2.0 mm) centre-of-mass displacement threshold in which case it would be possible to take full advantage of the accuracy and high imaging

  4. Predictive Parameters of CyberKnife Fiducial-less (XSight Lung) Applicability for Treatment of Early Non-Small Cell Lung Cancer: A Single-Center Experience

    SciTech Connect

    Bahig, Houda; Campeau, Marie-Pierre; Vu, Toni; Doucet, Robert; Béliveau Nadeau, Dominic; Fortin, Bernard; Roberge, David; Lambert, Louise; Carrier, Jean-François; Filion, Edith

    2013-11-01

    Purpose: To determine which parameters allow for CyberKnife fiducial-less tumor tracking in stereotactic body radiation therapy (SBRT) for early-stage non-small cell lung cancer. Methods and Materials: A total of 133 lung SBRT patients were preselected for direct soft-tissue tracking based on manufacturer recommendations (peripherally located tumors ≥1.5 cm with a dense appearance) and staff experience. Patients underwent a tumor visualization test to verify adequate detection by the tracking system (orthogonal radiographs). An analysis of potential predictors of successful tumor tracking was conducted looking at: tumor stage, size, histology, tumor projection on the vertebral column or mediastinum, distance to the diaphragm, lung-to-soft tissue ratio, and patient body mass index. Results: Tumor visualization was satisfactory for 88 patients (66%) and unsatisfactory for 45 patients (34%). Median time to treatment start was 6 days in the success group (range, 2-18 days) and 15 days (range, 3-63 days) in the failure group. A stage T2 (P=.04), larger tumor size (volume of 15.3 cm{sup 3} vs 6.5 cm{sup 3} in success and failure group, respectively) (P<.0001), and higher tumor density (0.86 g/cm{sup 3} vs 0.79 g/cm{sup 3}) were predictive of adequate detection. There was a 63% decrease in failure risk with every 1-cm increase in maximum tumor dimension (relative risk for failure = 0.37, CI=0.23-0.60, P=.001). A diameter of 3.6 cm predicted a success probability of 80%. Histology, lung-to-soft tissue ratio, distance to diaphragm, patient's body mass index, and tumor projection on vertebral column and mediastinum were not found to be predictive of success. Conclusions: Tumor size, volume, and density were the most predictive factors of a successful XSight Lung tumor tracking. Tumors >3.5 cm have ≥80% chance of being adequately visualized and therefore should all be considered for direct tumor tracking.

  5. Radiotherapy in patients with cardiac pacemakers.

    PubMed

    Last, A

    1998-01-01

    Patients with permanent cardiac pacemakers occasionally require radiotherapy. Therapeutic irradiation may cause pacemakers to malfunction due to the effects of ionizing radiation or electromagnetic interference. Modern pacemakers, using complementary metal oxide semiconductor (CMOS) circuitry, differ from older bipolar semiconductor devices both in their sensitivity to damage and the types of malfunction observed. The mechanisms and types of radiotherapy-induced pacemaker malfunction are described and in vitro and in vivo studies of pacemaker irradiation are reviewed. Some simple precautions are recommended during the planning and administration of radiotherapy to minimize the risk of harm to patients with pacemakers.

  6. Radiogenomics and radiotherapy response modeling

    NASA Astrophysics Data System (ADS)

    El Naqa, Issam; Kerns, Sarah L.; Coates, James; Luo, Yi; Speers, Corey; West, Catharine M. L.; Rosenstein, Barry S.; Ten Haken, Randall K.

    2017-08-01

    Advances in patient-specific information and biotechnology have contributed to a new era of computational medicine. Radiogenomics has emerged as a new field that investigates the role of genetics in treatment response to radiation therapy. Radiation oncology is currently attempting to embrace these recent advances and add to its rich history by maintaining its prominent role as a quantitative leader in oncologic response modeling. Here, we provide an overview of radiogenomics starting with genotyping, data aggregation, and application of different modeling approaches based on modifying traditional radiobiological methods or application of advanced machine learning techniques. We highlight the current status and potential for this new field to reshape the landscape of outcome modeling in radiotherapy and drive future advances in computational oncology.

  7. [Radiotherapy of benign intracranial tumors].

    PubMed

    Delannes, M; Latorzeff, I; Chand, M E; Huchet, A; Dupin, C; Colin, P

    2016-09-01

    Most of the benign intracranial tumors are meningiomas, vestibular schwannomas, pituitary adenomas, craniopharyngiomas, and glomus tumors. Some of them grow very slowly, and can be observed without specific treatment, especially if they are asymptomatic. Symptomatic or growing tumors are treated by surgery, which is the reference treatment. When surgery is not possible, due to the location of the lesion, or general conditions, radiotherapy can be applied, as it is if there is a postoperative growing residual tumor, or a local relapse. Indications have to be discussed in polydisciplinary meetings, with precise evaluation of the benefit and risks of the treatments. The techniques to be used are the most modern ones, as multimodal imaging and image-guided radiation therapy. Stereotactic treatments, using fractionated or single doses depending on the size or the location of the tumors, are commonly realized, to avoid as much a possible the occurrence of late side effects.

  8. Radiotherapy for Pancreatic Neuroendocrine Tumors

    SciTech Connect

    Contessa, Joseph N.; Griffith, Kent A.; Wolff, Elizabeth; Ensminger, William; Zalupski, Mark; Ben-Josef, Edgar

    2009-11-15

    Purpose: Pancreatic neuroendocrine tumors (PNTs) are rare malignant neoplasms considered to be resistant to radiotherapy (RT), although data on efficacy are scarce. We reviewed our institutional experience to further delineate the role of RT for patients with PNTs. Methods and Materials: Between 1986 and 2006, 36 patients with PNTs were treated with RT to 49 sites. Of these 36 patients, 23 had radiographic follow-up data, which were used to determine the tumor response rate and freedom from local progression. Long-term toxicity was graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events. Results: The overall response rate to RT was 39% (13% complete response, 26% partial response, 56% stable disease, and 4% progressive disease). A significant difference in the freedom from local progression between the groups receiving either greater than or less than the median 2 Gy/fraction biologically equivalent dose of 49.6 Gy was found, with all radiographic progression occurring in patients who had received <=32 Gy. The actuarial 3-year local freedom from progression rate was 49%. Palliation was achieved in 90% of patients, with either improvement or resolution of symptoms after RT. Of 35 patients, 33 had metastatic disease at their referral for RT, and the median overall survival for this patient population was 2 years. Three long-term Grade 3 or greater toxicities were recorded. Conclusion: RT is an effective modality for achieving local control in patients with PNTs. RT produces high rates of symptomatic palliation and freedom from local progression. Prospective trials of radiotherapy for PNTs are warranted.

  9. Intraoperative Radiotherapy in Childhood Malignant Astrocytoma

    PubMed Central

    Rana, Sohail R.; Haddy, Theresa B.; Ashayeri, Ebrahim; Goldson, Alfred L.

    1984-01-01

    A 12-year-old black male patient with glioblastoma multiforme was treated with intraoperative radiotherapy followed by conventional external beam radiation and chemotherapy. The authors' clinical experience with these therapeutic measures is discussed. PMID:6330375

  10. Heavy particle radiotherapy: prospects and pitfalls

    SciTech Connect

    Faju, M.R.

    1980-01-01

    The use of heavy particles in radiotherapy of tumor volumes is examined. Particles considered are protons, helium ions, heavy ions, negative pions, and fast neutrons. Advantages and disadvantages are discussed. (ACR)

  11. Imaging Instrumentation and Techniques for Precision Radiotherapy

    NASA Astrophysics Data System (ADS)

    Parodi, Katia; Parodi, Katia; Thieke, Christian; Thieke, Christian

    Over the last decade, several technological advances have considerably improved the achievable precision of dose delivery in radiation therapy. Clinical exploitation of the superior tumor-dose conformality offered by modern radiotherapy techniques like intensity-modulated radiotherapy and ion beam therapy requires morphological and functional assessment of the tumor during the entire therapy chain from treatment planning to beam application and treatment response evaluation. This chapter will address the main rationale and role of imaging in state-of-the-art external beam radiotherapy. Moreover, it will present the status of novel imaging instrumentation and techniques being nowadays introduced in clinical use or still under development for image guidance and, ultimately, dose guidance of precision radiotherapy.

  12. [Conformal radiotherapy for vertebral bone metastasis].

    PubMed

    Faivre, J C; Py, J F; Vogin, G; Martinage, G; Salleron, J; Royer, P; Grandgirard, N; Pasquier, D; Thureau, S

    2016-10-01

    Analgesic external beam radiation therapy is a standard of care for patients with uncomplicated painful bone metastases and/or prevention of bone complications. In case of fracture risk, radiation therapy is performed after surgery in a consolidation of an analgesic purpose and stabilizing osteosynthesis. Radiotherapy is mandatory after vertebroplasty or kyphoplasty. Spinal cord compression - the only emergency in radiation therapy - is indicated postoperatively either exclusively for non surgical indication. Analgesic re-irradiation is possible in the case of insufficient response or recurrent pain after radiotherapy. Metabolic radiation, bisphosphonates or denosumab do not dissuade external radiation therapy for pain relief. Systemic oncological treatments can be suspended with a period of wash out given the risk of radiosensitization or recall phenomenon. Better yet, the intensity modulated radiotherapy and stereotactic radiotherapy can be part of a curative strategy for oligometastatic patients and suggest new treatment prospects.

  13. [Radiotherapy of carcinoma of the salivary glands].

    PubMed

    Servagi-Vernat, S; Tochet, F

    2016-09-01

    Indication, doses, and technique of radiotherapy for salivary glands carcinoma are presented, and the contribution of neutrons and carbon ions. The recommendations for delineation of the target volumes and organs at risk are detailed.

  14. Historical aspects of heavy ion radiotherapy

    SciTech Connect

    Raju, M.R.

    1995-03-01

    This paper presents historical developments of heavy-ion radiotherapy including discussion of HILAC and HIMAC and discussion of cooperation between Japan and the United States, along with personal reflections.

  15. Intracranial aneurysm formation after radiotherapy for medulloblastoma

    PubMed Central

    Kamide, Tomoya; Mohri, Masanao; Misaki, Kouichi; Uchiyama, Naoyuki; Nakada, Mitsutoshi

    2016-01-01

    Background: The development of an intracranial aneurysm after radiotherapy is rare but secondary effect of cranial irradiation in a primary disease treatment. Case Description: The patient was a 17-year-old male adolescent who was diagnosed as having a posterior fossa medulloblastoma when he was 8 years old. He had undergone tumor resection with radiotherapy and chemotherapy. A distal posterior inferior cerebellar artery aneurysm was identified by magnetic resonance imaging 8 years after radiotherapy and grew rapidly throughout the next 1 year. The patient underwent microsurgical clipping and was discharged without deficit. Conclusion: This experience demonstrates that physicians caring for patients who have undergone intracranial radiotherapy should carefully consider the possibility of an aneurysmal formation when conducting follow-up imaging. PMID:27999713

  16. Pontine calcification following radiotherapy: CT demonstration.

    PubMed

    Price, D B; Hotson, G C; Loh, J P

    1988-01-01

    Development of pontine calcifications following radiation therapy for suprasellar tumors is described in two patients, 5 and 9 years old. Post-radiotherapy brain calcifications are rare in the brain stem.

  17. Blisters - an unusual effect during radiotherapy.

    PubMed

    Höller, U; Schubert, T; Budach, V; Trefzer, U; Beyer, M

    2013-11-01

    The skin reaction to radiation is regularly monitored in order to detect enhanced radiosensitivity of the patient, unexpected interactions (e.g. with drugs) or any inadvertent overdosage. It is important to distinguish secondary disease from radiation reaction to provide adequate treatment and to avoid unnecessary discontinuation of radiotherapy. A case of bullous eruption or blisters during radiotherapy of the breast is presented. Differential diagnoses bullous pemphigoid, pemphigus vulgaris, and bullous impetigo are discussed and treatment described.

  18. [Radiotherapy for small cell lung carcinoma].

    PubMed

    Pourel, N

    2016-10-01

    Radiotherapy for small cell lung carcinoma has known significant improvements over the past 10 years especially through routine use of PET-CT in the initial work-up and contouring before treatment. Prophylactic cranial irradiation remains a standard of care for locally advanced disease and is a subject of controversy for metastatic disease. A new indication for thoracic radiotherapy may soon arise for metastatic disease, still confirmation studies are ongoing.

  19. Radiotherapy in the treatment of vertebral hemangiomas

    SciTech Connect

    Faria, S.L.; Schlupp, W.R.; Chiminazzo, H. Jr.

    1985-02-01

    Symptomatic vertebral hemangiomas are not common. Although radiotherapy has been used as treatment, the data are sparse concerning total dose, fractionation and results. The authors report nine patients with vertebral hemangioma treated with 3000-4000 rad, 200 rad/day, 5 fractions per week, followed from 6 to 62 months. Seventy-seven percent had complete or almost complete disappearance of the symptoms. Radiotherapy schedules are discussed.

  20. Stereotactic multiple are radiotherapy. IV--Haemangioblastoma.

    PubMed

    Chakraborti, P R; Chakrabarti, K B; Doughty, D; Plowman, P N

    1997-04-01

    Our initial experience in the treatment of haemangioblastoma using conventional external beam radiotherapy and stereotactic radiotherapy (radiosurgery), by the linear accelerator method, is reported. Six haemangioblastomas in five patients were treated with a mean follow-up of 40 months (range 14-60). Five haemangioblastomas in four patients were treated with stereotactic radiotherapy, where four showed complete radiological response and the fifth was static. Neurological symptoms and signs improved in those patients. The sixth haemangioblastoma was situated close to the pituitary and optic chiasm, and was treated with conventionally fractionated external beam radiotherapy. The lesion showed partial response. No complications were noted in this patient group. This series complements and extends the relatively sparse published literature demonstrating that radiotherapy is an effective option for treating haemangioblastomas. Radiosurgery often lends itself particularly well to these discrete lesions allowing highly focused treatment. For patients with multiple and metachronous cerebellar haemangioblastomas as part of the von Hipple-Lindau syndrome, the data support a policy of conventionally fractionated external beam radiotherapy to the whole cerebellum of 50-55 Gy followed, after a period of time, by radiosurgery to persisting lesions (patients 3 and 4).

  1. Radiotherapy for Vestibular Schwannomas: A Critical Review

    SciTech Connect

    Murphy, Erin S.; Suh, John H.

    2011-03-15

    Vestibular schwannomas are slow-growing tumors of the myelin-forming cells that cover cranial nerve VIII. The treatment options for patients with vestibular schwannoma include active observation, surgical management, and radiotherapy. However, the optimal treatment choice remains controversial. We have reviewed the available data and summarized the radiotherapeutic options, including single-session stereotactic radiosurgery, fractionated conventional radiotherapy, fractionated stereotactic radiotherapy, and proton beam therapy. The comparisons of the various radiotherapy modalities have been based on single-institution experiences, which have shown excellent tumor control rates of 91-100%. Both stereotactic radiosurgery and fractionated stereotactic radiotherapy have successfully improved cranial nerve V and VII preservation to >95%. The mixed data regarding the ideal hearing preservation therapy, inherent biases in patient selection, and differences in outcome analysis have made the comparison across radiotherapeutic modalities difficult. Early experience using proton therapy for vestibular schwannoma treatment demonstrated local control rates of 84-100% but disappointing hearing preservation rates of 33-42%. Efforts to improve radiotherapy delivery will focus on refined dosimetry with the goal of reducing the dose to the critical structures. As future randomized trials are unlikely, we suggest regimented pre- and post-treatment assessments, including validated evaluations of cranial nerves V, VII, and VIII, and quality of life assessments with long-term prospective follow-up. The results from such trials will enhance the understanding of therapy outcomes and improve our ability to inform patients.

  2. SU-E-T-797: Variations of Cardiac Dose at Different Respiratory Status in CyberKnife M6â„¢ Treatment Plans for Accelerated Partial Breast Irradiation (APBI)

    SciTech Connect

    Long, S; Shang, C; Evans, G; Leventouri, T

    2015-06-15

    Purpose: Cyberknife robotic assisted radiation delivery has become a choice for accelerated breast RT, while a slightly increased cardiac dose has been reported. The dose dynamics throughout the respiration cycle has scarcely been explored. This study was designed to investigate the dose changes at each respiratory phase or status during respiration cycle. Methods: Six patients with 4DCT studies and six patients with a pair of free-breathing and deep breath-hold CT sets were used for dosimetry comparisons. 4DCT sets were obtained by Siemens™ CT and its respiratory gating system, comprising of 8 phases. Standard APBI plan at 340 cGy was done per fraction per NSABP B-39/RTOG 0413 and modulated with Cyberknife M6™ on MultiPlan™5.1.2. For the purpose of this study, the tumor volume was outlined in the media-lower quadrant of the left breast. Results: Except for D5cc in plans with 4DCT, cardiac doses are significantly different between respiratory phases in well inhaled breathing phases, and more significantly in plans with BH CT. Mean cardiac doses in 100% inhalation phase were often found to be 5–15% (p< 0.02) less than those in other phases. Conclusion: Although ineligible cardiac doses are noted in APBI plans using 4D free-breathing CT and instantaneous free breathing CT series, a reduction in cardiac dose was seen for the well-inhaled phases. This provides practical guidance for cardiac dose reduction applicable with CK M6 APBR.

  3. Validation of GEANT4 simulations for percentage depth dose calculations in heterogeneous media by using small photon beams from the 6-MV Cyberknife: Comparison with photon beam dosimetry with EBT2 film

    NASA Astrophysics Data System (ADS)

    Lee, Chung Il; Yoon, Sei-Chul; Shin, Jae Won; Hong, Seung-Woo; Suh, Tae Suk; Min, Kyung Joo; Lee, Sang Deok; Chung, Su Mi; Jung, Jae-Yong

    2015-04-01

    Percentage depth dose (PDD) distributions in heterogeneous phantoms with lung and soft bone equivalent media are studied by using the GEANT4 Monte Carlo code. For lung equivalent media, Balsa wood is used, and for soft bone equivalent media, a compound material with epoxy resin, hardener and calcium carbonate is used. Polystyrene slabs put together with these materials are used as a heterogeneous phantom. Dose measurements are performed with Gafchromic EBT2 film by using photon beams from the 6-MV CyberKnife at the Seoul Uridul Hospital. The cone sizes of the photon beams are varied from 5 to 10 to 30 mm. When the Balsa wood is inserted in the phantom, the dose measured with EBT2 film is found to be significantly different from the dose without the EBT2 film in and the dose beyond the Balsa wood region, particularly for small field sizes. On the other hand, when the soft bone equivalent material is inserted in the phantom, the discrepancy between the dose measured with EBT2 film and the dose without EBT2 film can be seen only in the region of the soft bone equivalent material. GEANT4 simulations are done with and without the EBT2 film to compare the simulation results with measurements. The GEANT4 simulations including EBT2 film are found to agree well with the measurements for all the cases within an error of 2.2%. The results of the present study show that GEANT4 gives reasonable results for the PDD calculations in heterogeneous media when using photon beams produced by the 6-MV CyberKnife

  4. [Radiotherapy for breast cancer and pacemaker].

    PubMed

    Menard, J; Campana, F; Kirov, K M; Bollet, M-A; Dendale, R; Fournier-Bidoz, N; Marchand, V; Mazal, A; Estève, M; Fourquet, A; Kirova, Y M

    2011-06-01

    Patients with permanent cardiac pacemakers occasionally require radiotherapy. Therapeutic irradiation may cause pacemakers to malfunction due to the effects of ionizing radiation or electromagnetic interference. We studied the breast cancer patients who needed breast and/or chest wall and lymph node irradiation to assess the feasibility and tolerance in this population of patients. From November 2008 to December 2009, more than 900 patients received radiotherapy for their breast cancer in our department using megavoltage linear accelerator (X 4-6 MV and electrons). Among them, seven patients were with permanent pacemaker. All patients have been treated to the breast and chest wall and/or lymph nodes. Total dose to breast and/or chest wall was 50 Gy/25 fractions and 46 Gy/23 fractions to lymph nodes. Patients who underwent conserving surgery followed by breast irradiation were boosted when indicated to tumour bed with 16 Gy/8 fractions. All patients were monitored everyday in presence of radiation oncologist to follow the function of their pacemaker. All pacemakers were controlled before and after radiotherapy by the patients' cardiologist. Seven patients were referred in our department for postoperative breast cancer radiotherapy. Among them, only one patient was declined for radiotherapy and underwent mastectomy without radiotherapy. In four cases the pacemaker was repositioned before the beginning of radiotherapy. Six patients, aged between 48 and 84 years underwent irradiation for their breast cancer. Four patients were treated with conserving surgery followed by breast radiotherapy and two with mastectomy followed by chest wall and internal mammary chain, supra- and infra-clavicular lymph node irradiation. The dose to the pacemaker generator was kept below 2 Gy. There was no pacemaker dysfunction observed during the radiotherapy. The multidisciplinary work with position change of the pacemaker before radiotherapy and everyday monitoring permitted the safe

  5. Adapting radiotherapy to hypoxic tumours

    NASA Astrophysics Data System (ADS)

    Malinen, Eirik; Søvik, Åste; Hristov, Dimitre; Bruland, Øyvind S.; Rune Olsen, Dag

    2006-10-01

    In the current work, the concepts of biologically adapted radiotherapy of hypoxic tumours in a framework encompassing functional tumour imaging, tumour control predictions, inverse treatment planning and intensity modulated radiotherapy (IMRT) were presented. Dynamic contrast enhanced magnetic resonance imaging (DCEMRI) of a spontaneous sarcoma in the nasal region of a dog was employed. The tracer concentration in the tumour was assumed related to the oxygen tension and compared to Eppendorf histograph measurements. Based on the pO2-related images derived from the MR analysis, the tumour was divided into four compartments by a segmentation procedure. DICOM structure sets for IMRT planning could be derived thereof. In order to display the possible advantages of non-uniform tumour doses, dose redistribution among the four tumour compartments was introduced. The dose redistribution was constrained by keeping the average dose to the tumour equal to a conventional target dose. The compartmental doses yielding optimum tumour control probability (TCP) were used as input in an inverse planning system, where the planning basis was the pO2-related tumour images from the MR analysis. Uniform (conventional) and non-uniform IMRT plans were scored both physically and biologically. The consequences of random and systematic errors in the compartmental images were evaluated. The normalized frequency distributions of the tracer concentration and the pO2 Eppendorf measurements were not significantly different. 28% of the tumour had, according to the MR analysis, pO2 values of less than 5 mm Hg. The optimum TCP following a non-uniform dose prescription was about four times higher than that following a uniform dose prescription. The non-uniform IMRT dose distribution resulting from the inverse planning gave a three times higher TCP than that of the uniform distribution. The TCP and the dose-based plan quality depended on IMRT parameters defined in the inverse planning procedure (fields

  6. Radiotherapy Treatment Planning for Testicular Seminoma

    SciTech Connect

    Wilder, Richard B.; Buyyounouski, Mark K.; Efstathiou, Jason A.; Beard, Clair J.

    2012-07-15

    Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 Multiplication-Sign 1-2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior-posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior-posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

  7. Modelling and simulation of radiotherapy

    NASA Astrophysics Data System (ADS)

    Kirkby, Norman F.

    2007-02-01

    In this paper, models are described which have been developed to model both the way in which a population of cells respond to radiation and the way in which a population of patients respond to radiotherapy to assist the conduct of clinical trials in silico. Population balance techniques have been used to simulate the age distribution of tumour cells in the cell cycle. Sensitivity to radiation is not constant round the cell cycle and a single fraction of radiation changes the age distribution. Careful timing of further fractions of radiation can be used to maximize the damage delivered to the tumour while minimizing damage to normal tissue. However, tumour modelling does not necessarily predict patient outcome. A separate model has been established to predict the course of a brain cancer called glioblastoma multiforme (GBM). The model considers the growth of the tumour and its effect on the normal brain. A simple representation is included of the health status of the patient and hence the type of treatment offered. It is concluded that although these and similar models have a long way yet to be developed, they are beginning to have an impact on the development of clinical practice.

  8. 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.

  9. A systematic review of antiproton radiotherapy

    NASA Astrophysics Data System (ADS)

    Bittner, Martin-Immanuel; Grosu, Anca-Ligia; Wiedenmann, Nicole; Wilkens, Jan

    2013-01-01

    Antiprotons have been proposed as possible particles for radiotherapy; over the past years, the renewed interest in the potential biomedical relevance led to an increased research activity. It is the aim of this review to deliver a comprehensive overview regarding the evidence accumulated so far, analysing the background and depicting the current status of antiprotons in radiotherapy. A literature search has been conducted, including major scientific and commercial databases. All articles and a number of relevant conference abstracts published in the respective field have been included in this systematic review. The physical basis of antiproton radiotherapy is complex; however, the characterisation of the energy deposition profile supports its potential use in radiotherapy. Also the dosimetry improved considerably over the past few years. Regarding the biological properties, data on the effects on cells are presented; however, definite conclusions regarding the relative biological effectiveness cannot be made at the moment and radiobiological evidence of enhanced effectiveness remains scarce. In addition, there is new evidence supporting the potential imaging properties, for example for online dose verification. Clinical settings which might profit from the use of antiprotons have been further tracked. Judging from the evidence available so far, clinical constellations requiring optimal sparing in the entrance region of the beam and re-irradiations might profit most from antiproton radiotherapy. While several open questions remain to be answered, first steps towards a thorough characterisation of this interesting modality have been made.

  10. A systematic review of antiproton radiotherapy

    NASA Astrophysics Data System (ADS)

    Bittner, Martin-Immanuel; Grosu, Anca-Ligia; Wiedenmann, Nicole; Wilkens, Jan

    2014-01-01

    Antiprotons have been proposed as possible particles for radiotherapy; over the past years, the renewed interest in the potential biomedical relevance led to an increased research activity. It is the aim of this review to deliver a comprehensive overview regarding the evidence accumulated so far, analysing the background and depicting the current status of antiprotons in radiotherapy. A literature search has been conducted, including major scientific and commercial databases. All articles and a number of relevant conference abstracts published in the respective field have been included in this systematic review. The physical basis of antiproton radiotherapy is complex; however, the characterisation of the energy deposition profile supports its potential use in radiotherapy. Also the dosimetry improved considerably over the past few years. Regarding the biological properties, data on the effects on cells are presented; however, definite conclusions regarding the relative biological effectiveness cannot be made at the moment and radiobiological evidence of enhanced effectiveness remains scarce. In addition, there is new evidence supporting the potential imaging properties, for example for online dose verification. Clinical settings which might profit from the use of antiprotons have been further tracked. Judging from the evidence available so far, clinical constellations requiring optimal sparing in the entrance region of the beam and re-irradiations might profit most from antiproton radiotherapy. While several open questions remain to be answered, first steps towards a thorough characterisation of this interesting modality have been made.

  11. Fiducial marker guided prostate radiotherapy: a review.

    PubMed

    O'Neill, Angela G M; Jain, Suneil; Hounsell, Alan R; O'Sullivan, Joe M

    2016-12-01

    Image-guided radiotherapy (IGRT) is an essential tool in the accurate delivery of modern radiotherapy techniques. Prostate radiotherapy positioned using skin marks or bony anatomy may be adequate for delivering a relatively homogeneous whole-pelvic radiotherapy dose, but these surrogates are not reliable when using reduced margins, dose escalation or hypofractionated stereotactic radiotherapy. Fiducial markers (FMs) for prostate IGRT have been in use since the 1990s. They require surgical implantation and provide a surrogate for the position of the prostate gland. A variety of FMs are available and they can be used in a number of ways. This review aimed to establish the evidence for using prostate FMs in terms of feasibility, implantation procedures, types of FMs used, FM migration, imaging modalities used and the clinical impact of FMs. A search strategy was defined and a literature search was carried out in Medline. Inclusion and exclusion criteria were applied, which resulted in 50 articles being included in this review. The evidence demonstrates that FMs provide a more accurate surrogate for the position of the prostate than either external skin marks or bony anatomy. A combination of FM alignment and soft-tissue analysis is currently the most effective and widely available approach to ensuring accuracy in prostate IGRT. FM implantation is safe and well tolerated. FM migration is possible but minimal. Standardization of all techniques and procedures in relation to the use of prostate FMs is required. Finally, a clinical trial investigating a non-surgical alternative to prostate FMs is introduced.

  12. A dose comparison of proton radiotherapy and photon radiotherapy for pediatric brain tumor

    NASA Astrophysics Data System (ADS)

    Kim, S. Y.; Cho, J. H.

    2014-12-01

    The purpose of this study was to investigate the effectiveness of photon radiotherapy and to compare the dose of treatment planning between proton radiotherapy and 3D conformal radiation therapy (3D-CRT) for pediatric brain tumor patients. This study was conducted in five pediatric brain tumor patients who underwent craniospinal irradiation treatment from October 2013 to April 2014 in the hospital. The study compared organs at risk (OARs) by assessing the dose distribution of normal tissue from the proton plan and 3D-CRT. Furthermore, this study assessed the treatment plans by looking at the homogeneity index (HI) and conformity index (CI). As a result, the study revealed OARs due to the small volume proton radiotherapy dose distribution in the normal tissue. Also, by comparing HI and CI between the 3D-CRT and proton radiotherapy plan, the study found that the dose of proton radiotherapy plan was homogenized. When conducting 3D-CRT and proton radiotherapy in a dose-volume histogram comparison, the dose of distribution turned out to be low. Consequently, proton radiotherapy is used for protecting the normal tissue, and is used in tumor tissue as a homogenized dose for effective treatment.

  13. Postoperative radiotherapy for prostate cancer : Morbidity of local-only or local-plus-pelvic radiotherapy.

    PubMed

    Waldstein, Cora; Dörr, Wolfgang; Pötter, Richard; Widder, Joachim; Goldner, Gregor

    2017-09-19

    The aim of this work was to characterise actuarial incidence and prevalence of early and late side effects of local versus pelvic three-dimensional conformal postoperative radiotherapy for prostate cancer. Based on a risk-adapted protocol, 575 patients received either local (n = 447) or local-plus-pelvic (n = 128) radiotherapy. Gastrointestinal (GI) and genitourinary (GU) side effects (≥grade 2 RTOG/EORTC criteria) were prospectively assessed. Maximum morbidity, actuarial incidence rate, and prevalence rates were compared between the two groups. For local radiotherapy, median follow-up was 68 months, and the mean dose was 66.7 Gy. In pelvic radiotherapy, the median follow-up was 49 months, and the mean local and pelvic doses were 66.9 and 48.3 Gy respectively. Early GI side effects ≥ G2 were detected in 26% and 42% of patients respectively (p < 0.001). Late GI adverse events were detected in 14% in both groups (p = 0.77). The 5‑year actuarial incidence rates were 14% and 14%, while the prevalence rates were 2% and 0% respectively. Early GU ≥ G2 side effects were detected in 15% and 16% (p = 0.96), while late GU morbidity was detected in 18% and 24% (p = 0.001). The 5‑year actuarial incidence rates were 16% and 35% (p = 0.001), while the respective prevalence rates were 6% and 8%. Despite the low prevalence of side effects, postoperative pelvic radiotherapy results in significant increases in the actuarial incidence of early GI and late GU morbidity using a conventional 4‑field box radiotherapy technique. Advanced treatment techniques like intensity-modulated radiotherapy (IMRT) or volumetric modulated arc radiotherapy (VMAT) should therefore be considered in pelvic radiotherapy to potentially reduce these side effects.

  14. Stereotactic radiosurgery - CyberKnife

    MedlinePlus

    ... slides into a machine that delivers radiation. A robotic arm controlled by a computer moves around you. ... DE, Adler JR Jr, Ewend MG. Image-guided robotic radiosurgery. In: Winn RH, ed. Youmans Neurological Surgery . ...

  15. Oral verrucous carcinoma. Treatment with radiotherapy

    SciTech Connect

    Nair, M.K.; Sankaranarayanan, R.; Padmanabhan, T.K.; Madhu, C.S.

    1988-02-01

    Fifty-two cases of oral verrucous carcinoma treated with radiotherapy at the Regional Cancer Centre, Trivandrum, Kerala, India in 1982 were evaluated to determine the distribution within the oral cavity, clinical extent, and effectiveness of radiotherapy in controlling the disease. The most common site was the buccal mucosa. Fifty percent of the patients had clinically negative regional lymph nodes and 33% were in earlier stages (T1, T2, N0, and M0). The overall 3-year no evidence of disease (NED) survival rate was 44%. The 3-year NED survival rate with radium implant was 86%. We cannot comment on anaplastic transformation after radiotherapy because our treatment failures have not been subjected for biopsy concerning this matter. Because the results are comparable with those of well-differentiated squamous cell carcinoma, we think that the treatment policies advocated for oral squamous cell carcinoma are also applicable to oral verrucous carcinoma.

  16. [Good practice of image-guided radiotherapy].

    PubMed

    de Crevoisier, R; Créhange, G; Castelli, J; Lafond, C; Delpon, G

    2015-10-01

    Image-guided radiotherapy (IGRT) aims to take into account the anatomical variations occurring during the course of radiotherapy, by direct or indirect visualization of the target volume followed by a corrective action. The movements of the target, or at least the set-up errors are corrected by moving the treatment table, corresponding to the simplest and most validated IGRT modality in a standard practice. The deformations of the target volume and organs at risk are however much more common, and unfortunately much more complicated to consider, requiring multiple planning before or during the treatment, corresponding to the adaptive radiotherapy strategies. The planning target volume must be carefully chosen according to these anatomic variations. This article reviews the modalities of IGRT, standard or under evaluation, according to the different tumour sites. Copyright © 2015. Published by Elsevier SAS.

  17. Operations experience at the Bevalac radiotherapy facility

    SciTech Connect

    Alonso, J.R.; Criswell, T.L.; Howard, J.; Chu, W.T.; Singh, R.P.; Geller, D.; Nyman, M.

    1981-03-01

    During the first years of Bevalac operation the biomedical effort concentrated on radiobiology work, laying the foundation for patient radiotherapy. A dedicated radiotherapy area was created in 1978, and in 1979 full-scale patient treatment was begun. As of now over 500 treatments with carbon, neon and argon beams have been delivered to about 50 patients, some as boosts from other modalities and some as complete heavy ion treatments. Up to 12 patients per day have been treated in this facility. Continuing efforts in refining techniques and operating procedures are increasing efficiency and accuracy of treatments, and are contributing to the alleviation of scheduling difficulties caused by the unique requirements of radiotherapy with human patients.

  18. Differences in breast tissue oxygenation following radiotherapy.

    PubMed

    Dornfeld, Ken; Gessert, Charles E; Renier, Colleen M; McNaney, David D; Urias, Rodolfo E; Knowles, Denise M; Beauduy, Jean L; Widell, Sherry L; McDonald, Bonita L

    2011-08-01

    Tissue perfusion and oxygenation changes following radiotherapy may result from and/or contribute to the toxicity of treatment. Breast tissue oxygenation levels were determined in the treated and non-treated breast 1 year after radiotherapy for breast conserving treatment. Transcutaneous oxygenation varied between subjects in both treated and non-treated breast. Subjects without diabetes mellitus (n=16) had an average oxygenation level of 64.8 ± 19.9mmHg in the irradiated breast and an average of 72.3 ± 18.1mmHg (p=0.018) at the corresponding location in the control breast. Patients with diabetes (n=4) showed a different oxygenation pattern, with lower oxygenation levels in control tissue and no decrease in the irradiated breast. This study suggests oxygenation levels in normal tissues vary between patients and may respond differently after radiotherapy.

  19. Assessment of post-radiotherapy salivary glands

    PubMed Central

    Cheng, S C H; Wu, V W C; Kwong, D L W; Ying, M T C

    2011-01-01

    Salivary glands are usually irradiated during radiotherapy for head and neck cancers, which can lead to radiation-induced damage. Radiation-induced xerostomia (oral dryness) is the most common post-radiotherapy complication for head and neck cancer patients and can reduce the patient’s quality of life. Accurate and efficient salivary gland assessment methods provide a better understanding of the cause and degree of xerostomia, and may help in patient management. At present, there are different methods for the assessment of salivary gland hypofunction; however, none of them are considered to be standard procedure. This article reviews the value of common methods in the assessment of post-radiotherapy salivary glands. PMID:21511748

  20. One hundred years of radiotherapy in Turkey.

    PubMed

    Dincer, M; Kuter, S

    2001-10-01

    The study and practice of radiology in Turkey began in 1897, only 2 years after the discovery of X-rays. A simple X-ray machine was constructed in Istanbul, consisting of a Crookes tube, a Ruhmkorff coil, and a home-made battery. This machine was first used on wounded soldiers, for diagnostic purposes. The first report of X-rays being used therapeutically in Turkey was published in a national journal in 1904. By 1933, the most up-to-date radiotherapy equipment of the time had been installed in every major city in the country. Innovative radiotherapy techniques, such as rotational treatment, were also being tried in 1930s. Today, there are 45 radiotherapy centres in Turkey, and 400 radiation oncologists and 80 medical physicists practise there.

  1. Radiotherapy-induced hypopituitarism: a review.

    PubMed

    Sathyapalan, Thozhukat; Dixit, Sanjay

    2012-05-01

    Hypopituitarism is a disorder caused by impaired hormonal secretions from the hypothalamic-pituitary axis. Radiotherapy is the most common cause of iatrogenic hypopituitarism. The hypothalamic-pituitary axis inadvertently gets irradiated in patients receiving prophylactic cranial radiotherapy for leukemia, total body irradiation and radiotherapy for intracranial, base skull, sinonasal and nasopharyngeal tumors. Radiation-induced hypopituitarism (RIH) is insidious, progressive and largely nonreversible. Mostly, RIH involves one hypothalamic-pituitary axis; however, multiple hormonal axes deficiency starts developing at higher doses. Although the clinical effects of the hypopituitarism are more profound in children and young adults, its implications in older adults are being increasingly recognized. The risk continues to persist or increase up to 10 years following radiation exposure. The clinical management of hypopituitarism is challenging both for the patients and healthcare providers. Here we have reviewed the scale of the problem, the risk factors and the management of RIH.

  2. Meningioma after radiotherapy for Hodgkin's disease.

    PubMed

    Deutsch, M; Rosenstein, M; Figura, J H

    1999-08-01

    The most common second primary tumors after treatment of childhood Hodgkin's disease are leukemia, lymphoma, breast cancer, soft tissue sarcoma, and thyroid cancer. Although intracranial meningioma has been reported after radiotherapy to the scalp for benign conditions and for intracranial primary brain tumors, this appears to be an extremely rare sequelae of treatment for Hodgkin's disease. The authors describe a 15-year-old boy who underwent radiotherapy for Hodgkin's disease and in whom a meningioma developed in the posterior fossa 27 years later.

  3. Pelvic radiotherapy and sexual function in women

    PubMed Central

    Froeding, Ligita Paskeviciute

    2015-01-01

    Background During the past decade there has been considerable progress in developing new radiation methods for cancer treatment. Pelvic radiotherapy constitutes the primary or (neo) adjuvant treatment of many pelvic cancers e.g., locally advanced cervical and rectal cancer. There is an increasing focus on late effects and an increasing awareness that patient reported outcomes (PROs) i.e., patient assessment of physical, social, psychological, and sexual functioning provides the most valid information on the effects of cancer treatment. Following cure of cancer allow survivors focus on quality of life (QOL) issues; sexual functioning has proved to be one of the most important aspects of concern in long-term survivors. Methods An updated literature search in PubMed was performed on pelvic radiotherapy and female sexual functioning/dysfunction. Studies on gynaecological, urological and gastrointestinal cancers were included. The focus was on the period from 2010 to 2014, on studies using PROs, on potential randomized controlled trials (RCTs) where female sexual dysfunction (FSD) at least constituted a secondary outcome, and on studies reporting from modern radiotherapy modalities. Results The literature search revealed a few RCTs with FSD evaluated as a PRO and being a secondary outcome measure in endometrial and in rectal cancer patients. Very limited information could be extracted regarding FSD in bladder, vulva, and anal cancer patients. The literature before and after 2010 confirms that pelvic radiotherapy, independent on modality, increases the risk significantly for FSD both compared to data from age-matched healthy control women and compared to data on patients treated by surgery only. There was only very limited data available on modern radiotherapy modalities. These are awaited during the next five years. Several newer studies confirm that health care professionals are still reluctant to discuss treatment induced sexual dysfunction with patients. Conclusions

  4. Radiotherapy in the management of early breast cancer

    SciTech Connect

    Wang, Wei

    2013-03-15

    Radiotherapy is an indispensible part of the management of all stages of breast cancer. In this article, the common indications for radiotherapy in the management of early breast cancer (stages 0, I, and II) are reviewed, including whole-breast radiotherapy as part of breast-conserving treatment for early invasive breast cancer and pre-invasive disease of ductal carcinoma in situ, post-mastectomy radiotherapy, locoregional radiotherapy, and partial breast irradiation. Key clinical studies that underpin our current practice are discussed briefly.

  5. The Leicester radiotherapy bite block: an aid to head and neck radiotherapy.

    PubMed

    Hollows, P; Hayter, J P; Vasanthan, S

    2001-02-01

    We describe the construction of a custom-made bite block to be used during external beam radiotherapy to the oral cavity. The bite block is made with standard maxillofacial prosthetic techniques and materials. The design allows accurate and reproducible positioning of the perioral tissues to aid planning of radiotherapy and treatment. The compressibility of this device improves comfort for the patient, while it is in use.

  6. Dosimetric and delivery efficiency investigation for treating hepatic lesions with a MLC-equipped robotic radiosurgery–radiotherapy combined system

    SciTech Connect

    Jin, Lihui Price, Robert A.; Wang, Lu; Meyer, Joshua; Fan, James; Charlie Ma, Chang Ming

    2016-02-15

    Purpose: The CyberKnife M6 (CK-M6) Series introduced a multileaf collimator (MLC) for extending its capability from stereotactic radiosurgery/stereotactic radiotherapy (SBRT) to conventionally fractionated radiotherapy. This work is to investigate the dosimetric quality of plans that are generated using MLC-shaped beams on the CK-M6, as well as their delivery time, via comparisons with the intensity modulated radiotherapy plans that were clinically used on a Varian Linac for treating hepatic lesions. Methods: Nine patient cases were selected and divided into three groups with three patients in each group: (1) the group-one patients were treated conventionally (25 fractions); (2) the group-two patients were treated with SBRT-like hypofractionation (5 fractions); and (3) the group-three patients were treated similar to group-one patients, but with two planning target volumes (PTVs) and two different prescription dose levels correspondingly. The clinically used plans were generated on the ECLIPSE treatment planning system (TPS) and delivered on a Varian Linac (E-V plans). The multiplan (MP) TPS was used to replan these clinical cases with the MLC as the beam device for the CK-M6 (C-M plans). After plans were normalized to the same PTV dose coverage, comparisons between the C-M and E-V plans were performed based on D{sub 99%} (percentage of prescription dose received by 99% of the PTV), D{sub 0.1cm{sup 3}} (the percentage of prescription dose to 0.1 cm{sup 3} of the PTV), and doses received by critical structures. Then, the delivery times for the C-M plans will be obtained, which are the MP TPS generated estimations assuming having an imaging interval of 60 s. Results: The difference in D{sub 99%} between C-M and E-V plans is +0.6% on average (+ or − indicating a higher or lower dose from C-M plans than from E-V plans) with a range from −4.1% to +3.8%, and the difference in D{sub 0.1cm{sup 3}} was −1.0% on average with a range from −5.1% to +2.9%. The PTV

  7. Hippocampal-sparing and target volume coverage in treating 3 to 10 brain metastases: A comparison of Gamma Knife, single-isocenter VMAT, CyberKnife, and TomoTherapy stereotactic radiosurgery.

    PubMed

    Zhang, Isabella; Antone, Jeff; Li, Jenny; Saha, Shyamali; Riegel, Adam C; Vijeh, Lili; Lauritano, Joe; Marrero, Mihaela; Salas, Sussan; Schulder, Michael; Zinkin, Heather; Goenka, Anuj; Knisely, Jonathan

    Our purpose was to evaluate hippocampal doses and target volume coverage with and without hippocampal sparing when treating multiple brain metastases using various stereotactic radiosurgery (SRS) platforms. We selected 10 consecutive patients with 14 separate treatments who had been treated in our department for 3 to 10 brain metastases and added hippocampal avoidance contours. All 14 treatments were planned with GammaPlan for Gamma Knife, Eclipse for single isocenter volumetric modulated arc therapy (VMAT), TomoTherapy Treatment Planning System (TPS) for TomoTherapy, and MultiPlan for CyberKnife. Initial planning was performed with the goal of planning target volume coverage of V100 ≥95% without hippocampal avoidance. If the maximum hippocampal point dose (Dmax) was <6.6 Gy in a single fraction and <40% of the hippocampi received ≤4.5 Gy, no second plan was performed. If either constraint was not met, replanning was performed with these constraints. There was a median of 6 metastases per plan, with an average total tumor volume of 7.32 mL per plan. The median hippocampal Dmax (in Gy) without sparing averaged 1.65, 9.81, 4.38, and 5.46, respectively (P < .0001). Of 14 plans, 3 Gamma Knife and CyberKnife plans required replanning, whereas 13 VMAT and 8 TomoTherapy plans required replanning. The hippocampal constraints were not achievable in 1 plan on any platform when the tumor was bordering the hippocampus. The mean volume of brain receiving 12 Gy (in mL), which has been associated with symptomatic radionecrosis, was 23.57 with Gamma Knife, 76.77 with VMAT, 40.86 with CyberKnife, and 104.06 with TomoTherapy (P = .01). The overall average conformity indices for all plans ranged from 0.36 to 0.52. Even with SRS, the hippocampi can receive a considerable dose; however, if the hippocampi are outlined as organs of risk, sparing these structures is feasible in nearly all situations with all 4 platforms, without detriment to target coverage, and should be considered

  8. Single-fraction spine SBRT end-to-end testing on TomoTherapy, Vero, TrueBeam, and CyberKnife treatment platforms using a novel anthropomorphic phantom.

    PubMed

    Gallo, John J; Kaufman, Isaac; Powell, Rachel; Pandya, Shalini; Somnay, Archana; Bossenberger, Todd; Ramirez, Ezequiel; Reynolds, Robert; Solberg, Timothy; Burmeister, Jay

    2015-01-08

    Spine SBRT involves the delivery of very high doses of radiation to targets adjacent to the spinal cord and is most commonly delivered in a single fraction. Highly conformal planning and accurate delivery of such plans is imperative for successful treatment without catastrophic adverse effects. End-to-end testing is an important practice for evaluating the entire treatment process from simulation through treatment delivery. We performed end-to-end testing for a set of representative spine targets planned and delivered using four different treatment planning systems (TPSs) and delivery systems to evaluate the various capabilities of each. An anthropomorphic E2E SBRT phantom was simulated and treated on each system to evaluate agreement between measured and calculated doses. The phantom accepts ion chambers in the thoracic region and radiochromic film in the lumbar region. Four representative targets were developed within each region (thoracic and lumbar) to represent different presentations of spinal metastases and planned according to RTOG 0631 constraints. Plans were created using the TomoTherapy TPS for delivery using the Hi·Art system, the iPlan TPS for delivery using the Vero system, the Eclipse TPS for delivery using the TrueBeam system in both flattened and flattening filter free (FFF), and the MultiPlan TPS for delivery using the CyberKnife system. Delivered doses were measured using a 0.007 cm3 ion chamber in the thoracic region and EBT3 GAFCHROMIC film in the lumbar region. Films were scanned and analyzed using an Epson Expression 10000XL flatbed scanner in conjunction with FilmQAPro2013. All treatment platforms met all dose constraints required by RTOG 0631. Ion chamber measurements in the thoracic targets delivered an overall average difference of 1.5%. Specifically, measurements agreed with the TPS to within 2.2%, 3.2%, 1.4%, 3.1%, and 3.0% for all three measureable cases on TomoTherapy, Vero, TrueBeam (FFF), TrueBeam (flattened), and CyberKnife

  9. [Stereotactic body radiotherapy for liver tumors: State of the art].

    PubMed

    Riou, O; Azria, D; Mornex, F

    2017-09-06

    Thanks to the improvement in radiotherapy physics, biology, computing and imaging, patients presenting with liver tumors can be efficiently treated by radiation. Radiotherapy has been included in liver tumors treatment guidelines at all disease stages. Liver stereotactic radiotherapy has to be preferred to standard fractionated radiotherapy whenever possible, as potentially more efficient because of higher biological equivalent dose. Liver stereotactic radiotherapy planning and delivery require extensive experience and optimal treatment quality at every step, thus limiting its availability to specialized centres. Multicentre studies are difficult to develop due to a large technical heterogeneity. Respiratory management, image guidance and immobilization are considerations as important as machine type. The use of multimodal planning imaging is compulsory to achieve expected contouring quality. Treatment efficacy is difficult to assess following liver stereotactic radiotherapy, but local control is high and toxicity unusual. As a consequence, liver stereotactic radiotherapy is part of multimodal and multidisciplinary management of liver tumors. Copyright © 2017. Published by Elsevier SAS.

  10. Post-radiotherapy hypothyroidism in dogs treated for thyroid carcinomas.

    PubMed

    Amores-Fuster, I; Cripps, P; Blackwood, L

    2017-03-01

    Hypothyroidism is a common adverse event after head and neck radiotherapy in human medicine, but uncommonly reported in canine patients. Records of 21 dogs with histologically or cytologically confirmed thyroid carcinoma receiving definitive or hypofractionated radiotherapy were reviewed. Nine cases received 48 Gy in 12 fractions, 10 received 36 Gy in 4 fractions and 2 received 32 Gy in 4 fractions. Seventeen cases had radiotherapy in a post-operative setting. Ten cases developed hypothyroidism (47.6%) after radiotherapy. The development of hypothyroidism was not associated with the radiotherapy protocol used. Median time to diagnosis of hypothyroidism was 6 months (range, 1-13 months). Hypothyroidism is a common side effect following radiotherapy for thyroid carcinomas. Monitoring of thyroid function following radiotherapy is recommended. No specific risk factors have been identified.

  11. Breast Cancer Patients’ Experience of External-Beam Radiotherapy

    PubMed Central

    Schnur, Julie B.; Ouellette, Suzanne C.; Bovbjerg, Dana H.; Montgomery, Guy H.

    2013-01-01

    Radiotherapy is a critical component of treatment for the majority of women with breast cancer, particularly those who receive breast conserving surgery. Although medically beneficial, radiotherapy can take a physical and psychological toll on patients. However, little is known about the specific thoughts and feelings experienced by women undergoing breast cancer radiotherapy. Therefore, the study aim was to use qualitative research methods to develop an understanding of these thoughts and feelings based on 180 diary entries, completed during radiotherapy by 15 women with Stage 0-III breast cancer. Thematic analysis identified four primary participant concerns: (a) a preoccupation with time; (b) fantasies (both optimistic and pessimistic) about life following radiotherapy; (c) the toll their side-effect experience takes on their self-esteem; and (d) feeling mystified by radiotherapy. These themes are consistent with previous literature on illness and identity. These findings have implications for the treatment and care of women undergoing breast cancer radiotherapy. PMID:19380502

  12. [Hopes of high dose-rate radiotherapy].

    PubMed

    Fouillade, Charles; Favaudon, Vincent; Vozenin, Marie-Catherine; Romeo, Paul-Henri; Bourhis, Jean; Verrelle, Pierre; Devauchelle, Patrick; Patriarca, Annalisa; Heinrich, Sophie; Mazal, Alejandro; Dutreix, Marie

    2017-04-01

    In this review, we present the synthesis of the newly acquired knowledge concerning high dose-rate irradiations and the hopes that these new radiotherapy modalities give rise to. The results were presented at a recent symposium on the subject. Copyright © 2017. Published by Elsevier Masson SAS.

  13. Radiotherapy for inverted papilloma: a case report.

    PubMed

    Levendag, P C; Annyas, A A; Escajadillo, J R; Elema, J D

    1984-06-01

    Inverted papilloma is an infrequent tumour of the nasal cavity and paranasal sinuses associated with controversy. The incidence of carcinoma in situ associated with inverted papilloma, has not been very well documented until now. Therefore, we present a case report characterized by an aggressive clinical behaviour, treated by extensive surgery and ultimately controlled by radiotherapy.

  14. Gold Nanoparticle Hyperthermia Reduces Radiotherapy Dose

    PubMed Central

    Lin, Lynn; Slatkin, Daniel N.; Dilmanian, F. Avraham; Vadas, Timothy M.; Smilowitz, Henry M.

    2014-01-01

    Gold nanoparticles can absorb near infrared light, resulting in heating and ablation of tumors. Gold nanoparticles have also been used for enhancing the dose of X-rays in tumors during radiotherapy. The combination of hyperthermia and radiotherapy is synergistic, importantly allowing a reduction in X-ray dose with improved therapeutic results. Here we intratumorally infused small 15 nm gold nanoparticles engineered to be transformed from infrared-transparent to infrared-absorptive by the tumor, which were then heated by infrared followed by X-ray treatment. Synergy was studied using a very radioresistant subcutaneous squamous cell carcinoma (SCCVII) in mice. It was found that the dose required to control 50% of the tumors, normally 55 Gy, could be reduced to <15 Gy (a factor of >3.7). Gold nanoparticles therefore provide a method to combine hyperthermia and radiotherapy to drastically reduce the X-ray radiation needed, thus sparing normal tissue, reducing the side effects, and making radiotherapy more effective. PMID:24990355

  15. Integer programming for improving radiotherapy treatment efficiency.

    PubMed

    Lv, Ming; Li, Yi; Kou, Bo; Zhou, Zhili

    2017-01-01

    Patients received by radiotherapy departments are diverse and may be diagnosed with different cancers. Therefore, they need different radiotherapy treatment plans and thus have different needs for medical resources. This research aims to explore the best method of scheduling the admission of patients receiving radiotherapy so as to reduce patient loss and maximize the usage efficiency of service resources. A mix integer programming (MIP) model integrated with special features of radiotherapy is constructed. The data used here is based on the historical data collected and we propose an exact method to solve the MIP model. Compared with the traditional First Come First Served (FCFS) method, the new method has boosted patient admission as well as the usage of linear accelerators (LINAC) and beds. The integer programming model can be used to describe the complex problem of scheduling radio-receiving patients, to identify the bottleneck resources that hinder patient admission, and to obtain the optimal LINAC-bed radio under the current data conditions. Different management strategies can be implemented by adjusting the settings of the MIP model. The computational results can serve as a reference for the policy-makers in decision making.

  16. Results of radiotherapy for Peyronie's disease

    SciTech Connect

    Niewald, Marcus . E-mail: ramnie@uniklinikum-saarland.de; Wenzlawowicz, Knut v.; Fleckenstein, Jochen; Wisser, Lothar; Derouet, Harry; Ruebe, Christian

    2006-01-01

    Purpose: To retrospectively review the results of radiotherapy for Peyronie's disease. Patients and Methods: In the time interval 1983-2000, 154 patients in our clinic were irradiated for Peyronie's disease. Of those, 101 had at least one complete follow-up data set and are the subject of this study. In the majority of patients, penis deviation was between 30 and 50{sup o}, there were one or two indurated foci with a diameter between 5 and 15 mm. Pain was recorded in 48/92 patients. Seventy-two of the 101 patients received radiotherapy with a total dose of 30 Gy, and 25 received 36 Gy in daily fractions of 2.0 Gy. The remaining patients received the following dosage: 34 Gy (1 patient), 38-40 Gy (3 patients). Mean duration of follow-up was 5 years. Results: The best results ever at any time during follow-up were an improvement of deviation in 47%, reduction of number of foci in 32%, reduction of size of foci in 49%, and less induration in 52%. Approximately 50% reported pain relief after radiotherapy. There were 28 patients with mild acute dermatitis and only 4 patients with mild urethritis. There were no long-term side effects. Conclusion: Our results compare well with those of other studies in the literature. In our patient cohort, radiotherapy was an effective therapy option with only very rare and mild side effects.

  17. TOPICAL REVIEW Dosimetry for ion beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Karger, Christian P.; Jäkel, Oliver; Palmans, Hugo; Kanai, Tatsuaki

    2010-11-01

    Recently, ion beam radiotherapy (including protons as well as heavier ions) gained considerable interest. Although ion beam radiotherapy requires dose prescription in terms of iso-effective dose (referring to an iso-effective photon dose), absorbed dose is still required as an operative quantity to control beam delivery, to characterize the beam dosimetrically and to verify dose delivery. This paper reviews current methods and standards to determine absorbed dose to water in ion beam radiotherapy, including (i) the detectors used to measure absorbed dose, (ii) dosimetry under reference conditions and (iii) dosimetry under non-reference conditions. Due to the LET dependence of the response of films and solid-state detectors, dosimetric measurements are mostly based on ion chambers. While a primary standard for ion beam radiotherapy still remains to be established, ion chamber dosimetry under reference conditions is based on similar protocols as for photons and electrons although the involved uncertainty is larger than for photon beams. For non-reference conditions, dose measurements in tissue-equivalent materials may also be necessary. Regarding the atomic numbers of the composites of tissue-equivalent phantoms, special requirements have to be fulfilled for ion beams. Methods for calibrating the beam monitor depend on whether passive or active beam delivery techniques are used. QA measurements are comparable to conventional radiotherapy; however, dose verification is usually single field rather than treatment plan based. Dose verification for active beam delivery techniques requires the use of multi-channel dosimetry systems to check the compliance of measured and calculated dose for a representative sample of measurement points. Although methods for ion beam dosimetry have been established, there is still room for developments. This includes improvement of the dosimetric accuracy as well as development of more efficient measurement techniques.

  18. Neo-adjuvant radiotherapy in rectal cancer

    PubMed Central

    Glimelius, Bengt

    2013-01-01

    In rectal cancer treatment, attention has focused on the local primary tumour and the regional tumour cell deposits to diminish the risk of a loco-regional recurrence. Several large randomized trials have also shown that combinations of surgery, radiotherapy and chemotherapy have markedly reduced the risk of a loco-regional recurrence, but this has not yet had any major influence on overall survival. The best results have been achieved when the radiotherapy has been given preoperatively. Preoperative radiotherapy improves loco-regional control even when surgery has been optimized to improve lateral clearance, i.e., when a total mesorectal excision has been performed. The relative reduction is then 50%-70%. The value of radiotherapy has not been tested in combination with more extensive surgery including lateral lymph node clearance, as practised in some Asian countries. Many details about how the radiotherapy is performed are still open for discussion, and practice varies between countries. A highly fractionated radiation schedule (5 Gy × 5), proven efficacious in many trials, has gained much popularity in some countries, whereas a conventionally fractionated regimen (1.8-2.0 Gy × 25-28), often combined with chemotherapy, is used in other countries. The additional therapy adds morbidity to the morbidity that surgery causes, and should therefore be administered only when the risk of loco-regional recurrence is sufficiently high. The best integration of the weakest modality, to date the drugs (conventional cytotoxics and biologicals) is not known. A new generation of trials exploring the best sequence of treatments is required. Furthermore, there is a great need to develop predictors of response, so that treatment can be further individualized and not solely based upon clinical factors and anatomic imaging. PMID:24379566

  19. Monte Carlo simulated corrections for beam commissioning measurements with circular and MLC shaped fields on the CyberKnife M6 System: a study including diode, microchamber, point scintillator, and synthetic microdiamond detectors

    NASA Astrophysics Data System (ADS)

    Francescon, P.; Kilby, W.; Noll, J. M.; Masi, L.; Satariano, N.; Russo, S.

    2017-02-01

    Monte Carlo simulation was used to calculate correction factors for output factor (OF), percentage depth-dose (PDD), and off-axis ratio (OAR) measurements with the CyberKnife M6 System. These include the first such data for the InCise MLC. Simulated detectors include diodes, air-filled microchambers, a synthetic microdiamond detector, and point scintillator. Individual perturbation factors were also evaluated. OF corrections show similar trends to previous studies. With a 5 mm fixed collimator the diode correction to convert a measured OF to the corresponding point dose ratio varies between  ‑6.1% and  ‑3.5% for the diode models evaluated, while in a 7.6 mm  ×  7.7 mm MLC field these are  ‑4.5% to  ‑1.8%. The corresponding microchamber corrections are  +9.9% to  +10.7% and  +3.5% to  +4.0%. The microdiamond corrections have a maximum of  ‑1.4% for the 7.5 mm and 10 mm collimators. The scintillator corrections are  <1% in all beams. Measured OF showed uncorrected inter-detector differences  >15%, reducing to  <3% after correction. PDD corrections at d  >  d max were  <2% for all detectors except IBA Razor where a maximum 4% correction was observed at 300 mm depth. OAR corrections were smaller inside the field than outside. At the beam edge microchamber OAR corrections were up to 15%, mainly caused by density perturbations, which blurs the measured penumbra. With larger beams and depths, PTW and IBA diode corrections outside the beam were up to 20% while the Edge detector needed smaller corrections although these did vary with orientation. These effects are most noticeable for large field size and depth, where they are dominated by fluence and stopping power perturbations. The microdiamond OAR corrections were  <3% outside the beam. This paper provides OF corrections that can be used for commissioning new CyberKnife M6 Systems and retrospectively checking estimated

  20. SU-E-T-225: Correction Matrix for PinPoint Ionization Chamber for Dosimetric Measurements in the Newly Released Incise™ Multileaf Collimator Shaped Small Field for CyberKnife M6™ Machine

    SciTech Connect

    Zhang, Y; Li, T; Heron, D; Huq, M

    2015-06-15

    Purpose: For small field dosimetry, such as measurements of output factors for cones or MLC-shaped irregular small fields, ion chambers often Result in an underestimation of the dose, due to both the volume averaging effect and the lack of lateral charged particle equilibrium. This work presents a mathematical model for correction matrix for a PTW PinPoint ionization chamber for dosimetric measurements made in the newly released Incise™ Multileaf collimator fields of the CyberKnife M6™ machine. Methods: A correction matrix for a PTW 0.015cc PinPoint ionization chamber was developed by modeling its 3D dose response in twelve cone-shaped circular fields created using the 5mm, 7.5mm, 10mm, 12.5mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 50mm, 60mm cones in a CyberKnife M6™ machine. For each field size, hundreds of readings were recorded for every 2mm chamber shift in the horizontal plane. The contribution of each dose pixel to a measurement point depended on the radial distance and the angle to the chamber axis. These readings were then compared with the theoretical dose as obtained with Monte Carlo calculation. A penalized least-square optimization algorithm was developed to generate the correction matrix. After the parameter fitting, the mathematical model was validated for MLC-shaped irregular fields. Results: The optimization algorithm used for parameter fitting was stable and the resulted response factors were smooth in spatial domain. After correction with the mathematical model, the chamber reading matched with the calculation for all the tested fields to within 2%. Conclusion: A novel mathematical model has been developed for PinPoint chamber for dosimetric measurements in small MLC-shaped irregular fields. The correction matrix is dependent on detector, treatment unit and the geometry of setup. The model can be applied to non-standard composite fields and provides an access to IMRT point dose validation.

  1. Technical advances in external radiotherapy for hepatocellular carcinoma

    PubMed Central

    Park, Shin-Hyung; Kim, Jae-Chul; Kang, Min Kyu

    2016-01-01

    Radiotherapy techniques have substantially improved in the last two decades. After the introduction of 3-dimensional conformal radiotherapy, radiotherapy has been increasingly used for the treatment of hepatocellular carcinoma (HCC). Currently, more advanced techniques, including intensity-modulated radiotherapy (IMRT), stereotactic ablative body radiotherapy (SABR), and charged particle therapy, are used for the treatment of HCC. IMRT can escalate the tumor dose while sparing the normal tissue even though the tumor is large or located near critical organs. SABR can deliver a very high radiation dose to small HCCs in a few fractions, leading to high local control rates of 84%-100%. Various advanced imaging modalities are used for radiotherapy planning and delivery to improve the precision of radiotherapy. These advanced techniques enable the delivery of high dose radiotherapy for early to advanced HCCs without increasing the radiation-induced toxicities. However, as there have been no effective tools for the prediction of the response to radiotherapy or recurrences within or outside the radiation field, future studies should focus on selecting the patients who will benefit from radiotherapy. PMID:27621577

  2. [Nutritional assistance to patients during radiotherapy].

    PubMed

    Dias, M C; Nadalin, W; Baxter, Y C; Faintuch, J; Waitzberg, D L; Maculevicius, J

    1996-01-01

    With the aim of assessing the possible benefits of nutritional therapy, 140 patients were prospectively studied during radiotherapy of the head and neck (81%) and esophageal cancer (19%). Mean age was 56.0 (17-80), with 114 males and 26 females. Duration of both nutrition and radiotherapy was 78.0 +/- 45 days. Tube feeding was the primary modality in 50.7% of the population, and oral regimens in the remaining 49.3%, but associations between the methods were also used. Enteral diets were supplied under the supervision of a specialized tem for home alimentation (PROSNED). Compliance to the program was 100%, and a lymphocyte count diminished along this period (1933 +/- 1033 vs 1265 +/- 688, p. 0.001). A subjective improvement was reported by 84% of the population, and total calorie intake, that was below 60% of estimated needs in 100% of the cases initially, significantly improved to just 40% inadequate at the end of the observations. Radiotherapy was associated with mucositis in 21% of the patients, taste changes in 79%, xerostomy in 81%, anorexia in 66% and odinophagia in 59%. In the individuals selected for enteral feeding, side-effects were represented by technical problems (20%) and gastrointestinal disorders (13%). All patients completed the nutritional support program and there was no mortality in this series. It is concluded that; 1) Early nutritional support during radiotherapy was able to maintain or improve the nutritional status; 2) Tube feeding, alone or in combination with oral diets, was indicated whenever appropriate and contributed to fulfillment of the energy requirements; 3) Reduction of total lymphocytes could not be prevented by the mentioned therapy; 4) Complications of enteral alimentation were mild and affected a small proportion of the population; 5) Troubles induced by radiotherapy were as frequent as expected, and tended to disturb the intake of food; 6) The compliance to the therapeutic plan was excellent and can be attributed to the

  3. Comparison of Planned Dose Distributions Calculated by Monte Carlo and Ray-Trace Algorithms for the Treatment of Lung Tumors With CyberKnife: A Preliminary Study in 33 Patients

    SciTech Connect

    Wilcox, Ellen E.; Daskalov, George M.; Lincoln, Holly; Shumway, Richard C.; Kaplan, Bruce M.; Colasanto, Joseph M.

    2010-05-01

    Purpose: To compare dose distributions calculated using the Monte Carlo algorithm (MC) and Ray-Trace algorithm (effective path length method, EPL) for CyberKnife treatments of lung tumors. Materials and Methods: An acceptable treatment plan is created using Multiplan 2.1 and MC dose calculation. Dose is prescribed to the isodose line encompassing 95% of the planning target volume (PTV) and this is the plan clinically delivered. For comparison, the Ray-Trace algorithm with heterogeneity correction (EPL) is used to recalculate the dose distribution for this plan using the same beams, beam directions, and monitor units (MUs). Results: The maximum doses calculated by the EPL to target PTV are uniformly larger than the MC plans by up to a factor of 1.63. Up to a factor of four larger maximum dose differences are observed for the critical structures in the chest. More beams traversing larger distances through low density lung are associated with larger differences, consistent with the fact that the EPL overestimates doses in low-density structures and this effect is more pronounced as collimator size decreases. Conclusions: We establish that changing the treatment plan calculation algorithm from EPL to MC can produce large differences in target and critical organs' dose coverage. The observed discrepancies are larger for plans using smaller collimator sizes and have strong dependency on the anatomical relationship of target-critical structures.

  4. Perianal Paget disease treated definitively with radiotherapy.

    PubMed

    Mann, J; Lavaf, A; Tejwani, A; Ross, P; Ashamalla, H

    2012-12-01

    Extramammary Paget disease (empd) is a relatively rare cutaneous disorder described as an apocrine gland tumour occurring in both a benign and a malignant form with metastatic potential. The areas of the body affected are the vulva, perianal region, penis, scrotum, perineum, and axilla, all of which contain apocrine glands. When empd affects the perianal region, it is called perianal Paget disease (ppd). All forms of empd, including ppd, are typically treated by wide surgical excision. Perianal Paget disease usually occurs later in life in patients who are often poor surgical candidates, but the available literature is scarce regarding other treatment modalities, including definitive radiotherapy. We contend that ppd can be safely and effectively treated with radiotherapy, and here, we present the case of a 75-year-old woman with ppd who was successfully so treated. A brief review of the literature concerning the diagnosis, natural history, and treatment of ppd is also included.

  5. [Radiotherapy as primary treatment for chemodectoma?].

    PubMed

    Verniers, D; Van Limbergen, E; Leysen, J; Ostyn, F; Segers, A

    1990-01-01

    Chemodectomas are slowly growing tumours originating in the chemoreceptor bodies. The diagnosis is based on typical clinical symptoms and radiological investigation. CT scanning with contrast enhancement permits to establish diagnosis in most cases and gives a correct idea of tumour size, tumour extension, displacement of arteries and bone destruction. Small tympanic chemodectomas are successfully managed by surgery, without causing additional cranial nerve palsies. Surgery of larger lesions is frequently followed by a high percentage of local recurrence (greater than 50%) and important morbidity (neurologic sequelae). Our present series confirms that these tumours can successfully be treated by radiotherapy. Persisting local control rates can be obtained in more than 90% of cases with moderate doses (45-50 Gy in 5 weeks) of carefully planned radiotherapy.

  6. [Difficult situations in radiotherapy: agitated adult patients].

    PubMed

    Noël, S; Noël, G

    2013-10-01

    The causes of agitation in adult patients are numerous. Agitation may cause difficulty or impossibility to initiate the radiotherapy technique but also can lead to accidents harmful to patients. However, the decision to not irradiate agitated patients may lead to a loss of curability chance or chance to palliate symptoms. Before taking such a decision, thinking about the possibilities available to calm the patient should be undertaken with the patient and the referring practitioners to attempt to make this therapy if it is considered major in the management of cancer. In all cases, current adaptations of radiotherapy should be used to deliver an effective radiation of a suitable time and safely. It is notable that the medical literature is extremely rare on this subject. Copyright © 2013 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  7. [Radiotherapy and targeted therapy/immunotherapy].

    PubMed

    Antoni, D; Bockel, S; Deutsch, E; Mornex, F

    2016-10-01

    Thanks to recent advances achieved in oncologic systemic and local ablative treatment, the treatments become more and more efficient in term of local control and overall survival. Thus, the targeted therapies, immunotherapy or stereotactic radiotherapy have modified the management of patients, especially in case of oligometastatic disease. Many questions are raised by these innovations, particularly the diagnosis and management of new side effects or that of the combination of these different treatments, depending on the type of primary tumor. Fundamental data are available, while clinical data are still limited. Ongoing trials should help to clarify the clinical management protocols. This manuscript is a review of the combination of radiotherapy and targeted therapy/immunotherapy.

  8. Second cancers following radiotherapy for cancer

    SciTech Connect

    Curtis, R.E.

    1997-03-01

    The study of second cancer risk after radiotherapy provides a unique opportunity to study carcinogenesis since large groups of humans are deliberately exposed to substantial doses of radiation in order to cure disease. Detailed radiotherapy records for cancer patients allow precise quantification of organ dose, and population-based cancer registries are frequently available to provide access to large groups of patients who are closely followed for long periods. Moreover, cancer patients treated with surgery alone (no radiation) are frequently available to serve as a non-irradiated comparison group. New information can be provided on relatively insensitive organs, and low dose exposures in the range of scientific interest are received by organs outside the radiation treatment fields. This paper will review several recently completed studies that characterize the risk of radiation-induced second cancers. Emphasis will be given to studies providing new information on the dose-response relationship of radiation-induced leukemia, breast cancer and lung cancer.

  9. Postoperative stereotactic body radiotherapy for spinal metastases.

    PubMed

    Alghamdi, Majed; Tseng, Chia-Lin; Myrehaug, Sten; Maralani, Pejman; Heyn, Chris; Soliman, Hany; Lee, Young; Ruschin, Mark; Da Costa, Leodante; Yang, Victor; Campbell, Mikki; Sahgal, Arjun

    2017-09-01

    Spine is a common site of metastases in cancer patients. Spine surgery is indicated for select patients, typically those with mechanical instability and/or malignant epidural spinal cord (or cauda equina) compression. Although post-operative conventional palliative external beam radiation therapy has been the standard of care, technical improvements in radiation planning and image-guided radiotherapy have allowed for the application of stereotactic body radiotherapy (SBRT) to the spine. Spine SBRT is intended to ablate residual tumor and optimize local control by delivering several fold greater biologically effective doses. Early clinical experience of postoperative spinal SBRT report encouraging results in terms of safety and efficacy. In this review, we summarize the clinical and technical aspects pertinent to a safe and effective practice of postoperative SBRT for spinal metastases.

  10. Complications of surgery for radiotherapy skin damage

    SciTech Connect

    Rudolph, R.

    1982-08-01

    Complications of modern surgery for radiotherapy skin damage reviewed in 28 patients who had 42 operations. Thin split-thickness skin grafts for ulcer treatment had a 100 percent complication rate, defined as the need for further surgery. Local flaps, whether delayed or not, also had a high rate of complications. Myocutaneous flaps for ulcers had a 43 percent complication rate, with viable flaps lifting off radiated wound beds. Only myocutaneous flaps for breast reconstruction and omental flaps with skin grafts and Marlex mesh had no complications. The deeper tissue penetration of modern radiotherapy techniques may make skin grafts and flaps less useful. In reconstruction of radiation ulcers, omental flaps and myocutaneous flaps are especially useful, particularly if the radiation damage can be fully excised. The pull of gravity appears detrimental to myocutaneous flap healing and, if possible, should be avoided by flap design.

  11. Proton Radiotherapy for Solid Tumors of Childhood

    PubMed Central

    Cotter, Shane E.; McBride, Sean M.; Yock, Torunn I.

    2012-01-01

    The increasing efficacy of pediatric cancer therapy over the past four decades has produced many long-term survivors that now struggle with serious treatment related morbidities affecting their quality of life. Radiation therapy is responsible for a significant proportion of these late effects, but a relatively new and emerging modality, proton radiotherapy hold great promise to drastically reduce these treatment related late effects in long term survivors by sparing dose to normal tissues. Dosimetric studies of proton radiotherapy compared with best available photon based treatment show significant dose sparing to developing normal tissues. Furthermore, clinical data are now emerging that begin to quantify the benefit in decreased late treatment effects while maintaining excellent cancer control rates. PMID:22417062

  12. Status of radiotherapy in a multidisciplinary cancer board.

    PubMed

    Ichikawa, Mayumi; Nemoto, Kenji; Miwa, Misako; Ohta, Ibuki; Nomiya, Takuma; Yamakawa, Mayumi; Itho, Yuriko; Fukui, Tadahisa; Yoshioka, Takashi

    2014-03-01

    Multidisciplinary cancer boards (CBs) for making cancer treatment decisions have become popular in many countries; however, the status of radiotherapy in CBs and the influence of CBs on radiotherapy decisions have not been studied. To clarify these issues, we reviewed the minutes of our CBs from February 2010 to March 2012, and we classified planned treatments discussed at the CBs into five categories and analyzed decisions concerning radiotherapy in each category. The fraction of cases for which radiotherapy was recommended was 536/757 (71%). These cases included 478 cases (63%) for which radiation therapy was planned and four cases (0.5%) for which radiation therapy was unexpectedly recommended. On the other hand, radiation therapy was canceled in 21 cases (4%) for which radiation therapy had been planned. This study showed that radiotherapy was discussed in many cases at CBs and that CBs have a great influence on decisions concerning radiotherapy.

  13. Radiotherapy in Dupuytren's disease: a systematic review of the evidence.

    PubMed

    Kadhum, M; Smock, E; Khan, A; Fleming, A

    2017-09-01

    Radiotherapy has been advocated as an alternative treatment in early Dupuytren's disease. We have systematically reviewed the evidence on the use of radiotherapy in Dupuytren's disease. Only six articles met a minimum set standard, five of which were retrospective cohort studies and one a randomized controlled study. A total of 770 Dupuytren's hands, nearly all with Tubiana stage 0-1 disease, were irradiated with an average 30 Gy. Disease regression ranged from 0%-56%, stability from 14%-98% and progression from 2%-86%. Salvage surgery was successful in all cases of disease progression post-radiotherapy. There were no reports of adverse wound healing problems associated with such surgery or radiotherapy-associated malignancy. On balance, radiotherapy should be considered an unproven treatment for early Dupuytren's disease due to a scarce evidence base and unknown long-term adverse effects. Well-designed randomized controlled studies are required to confirm the benefits of radiotherapy treatment. II.

  14. Evaluation of the peripheral dose in stereotactic radiotherapy and radiosurgery treatments1

    PubMed Central

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

    2010-01-01

    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. PMID:20831066

  15. Pelvic Fractures After Radiotherapy for Cervical Cancer

    PubMed Central

    Schmeler, Kathleen M.; Jhingran, Anuja; Iyer, Revathy B.; Sun, Charlotte C.; Eifel, Patricia J.; Soliman, Pamela T.; Ramirez, Pedro T.; Frumovitz, Michael; Bodurka, Diane C.; Sood, Anil K.

    2016-01-01

    BACKGROUND The incidence of pelvic fractures and associated risk factors was determined in women treated with curative-intent radiotherapy for cervical cancer. METHODS The records of 516 women treated with curative-intent radiotherapy for cervical cancer between 2001 and 2006 at the University of Texas M. D. Anderson Cancer Center were reviewed. Among these, 300 patients had at least 1 post-treatment computed tomography scan or magnetic resonance imaging study available for review, and they comprised our study population. All imaging studies were re-reviewed by a single radiologist to evaluate for fractures. RESULTS Pelvic fractures were noted in 29 of 300 patients (9.7%). Fracture sites included sacrum (n = 24; 83%), sacrum and pubis (n = 3; 10%), iliac crest (n = 1; 3%), and sacrum and acetabulum (n = 1; 3%). Thirteen patients (45%) were symptomatic, with pain being the most common presenting symptom. The median time from the completion of radiotherapy to the detection of fractures on imaging studies was 14.1 months (range, 2.1–63.1 months), with 38% of patients diagnosed within 1 year and 83% diagnosed within 2 years of completing therapy. The median age of the patients at diagnosis was higher in the women who developed a fracture compared with the women who did not (56.5 years vs 46.7 years; P = .04). A higher number of women with a fracture were postmenopausal (62% vs 37%; P = .03). The median body mass index was lower in the women who had a fracture (26.0 kg/m2 vs 28.0 kg/m2; P = .03). CONCLUSIONS Pelvic fractures were detected in a substantial proportion of women after radiotherapy for cervical cancer. Bone mineral density screening and pharmacologic intervention should be considered in these women. PMID:20052724

  16. Targeting Radiotherapy to Cancer by Gene Transfer

    PubMed Central

    2003-01-01

    Targeted radionuclide therapy is an alternative method of radiation treatment which uses a tumor-seeking agent carrying a radioactive atom to deposits of tumor, wherever in the body they may be located. Recent experimental data signifies promise for the amalgamation of gene transfer with radionuclide targeting. This review encompasses aspects of the integration of gene manipulation and targeted radiotherapy, highlighting the possibilities of gene transfer to assist the targeting of cancer with low molecular weight radiopharmaceuticals. PMID:12721515

  17. Radiotherapy equipment--purchase or lease?

    PubMed

    Nisbet, A; Ward, A

    2001-08-01

    Against a background of increasing demand for radiotherapy equipment, this study was undertaken to investigate options for equipment procurement, in particular to compare purchase with lease. The perceived advantages of lease are that equipment can be acquired within budget and cashflow constraints, with relatively low amounts of cash leaving the NHS in the first year, avoiding the necessity of capitalizing the equipment and providing protection against the risk of obsolescence associated with high technology equipment. The perceived disadvantages of leasing are that the Trust does not own the equipment, leasing can be more expensive in revenue terms, the tender process is extended and there may be lease conditions to be met, which may be costly and/or restrictive. There are also a number of technical considerations involved in the leasing of radiotherapy equipment that influence the financial analysis and practical operation of the radiotherapy service. The technical considerations include servicing and planned preventative maintenance, upgrades, spare parts, subsequent purchase of "add ons", modification of equipment, research and development work, commencement of the lease period, return of equipment at the end of the lease period and negotiations at the end of the lease period. A study from Raigmore Hospital, Inverness is described, which involves the procurement of new, state-of-the-art radiotherapy equipment. This provides an overview of the procurement process, including a summary of the advantages and disadvantages of leasing, with the figures from the financial analysis presented and explained. In addition, a detailed description is given of the technical considerations to be taken into account in the financial analysis and negotiation of any lease contract.

  18. Hypothyroidism After Radiotherapy for Nasopharyngeal Cancer Patients

    SciTech Connect

    Wu, Y.-H.; Wang, H-M.; Chen, Hellen Hi-Wen; Lin, C.-Y.; Chen, Eric Yen-Chao; Fan, K.-H.; Huang, S.-F.; Chen, I-How; Liao, C.-T.; Cheng, Ann-Joy; Chang, Joseph Tung-Chieh

    2010-03-15

    Purpose: The aim of this study was to determine the long-term incidence and possible predictive factors for posttreatment hypothyroidism in nasopharyngeal carcinoma (NPC) patients after radiotherapy. Methods and Materials: Four hundred and eight sequential NPC patients who had received regular annual thyroid hormone surveys prospectively after radiotherapy were included in this study. Median patient age was 47.3 years, and 286 patients were male. Thyroid function was prospectively evaluated by measuring thyroid-stimulating hormone (TSH) and serum free thyroxine (FT4) levels. Low FT4 levels indicated clinical hypothyroidism in this study. Results: With a median follow-up of 4.3 years (range, 0.54-19.7 years), the incidence of low FT4 level was 5.3%, 9.0%, and 19.1% at 3, 5, and 10 years after radiotherapy, respectively. Hypothyroidism was more common with early T stage (p = 0.044), female sex (p = 0.037), and three-dimensional conformal therapy with the altered fractionation technique (p = 0.005) after univariate analysis. N stage, chemotherapy, reirradiation, and neck electron boost did not affect the incidence of hypothyroidism. Younger age and conformal therapy were significant factors that determined clinical hypothyroidism after multivariate analysis. Overall, patients presented with a low FT4 level about 1 year after presenting with an elevated TSH level. Conclusion: Among our study group of NPC patients, 19.1% experienced clinical hypothyroidism by 10 years after treatment. Younger age and conformal therapy increased the risk of hypothyroidism. We suggest routine evaluation of thyroid function in NPC patients after radiotherapy. The impact of pituitary injury should be also considered.

  19. Current concepts on imaging in radiotherapy.

    PubMed

    Lecchi, Michela; Fossati, Piero; Elisei, Federica; Orecchia, Roberto; Lucignani, Giovanni

    2008-04-01

    New high-precision radiotherapy (RT) techniques, such as intensity-modulated radiation therapy (IMRT) or hadrontherapy, allow better dose distribution within the target and spare a larger portion of normal tissue than conventional RT. These techniques require accurate tumour volume delineation and intrinsic characterization, as well as verification of target localisation and monitoring of organ motion and response assessment during treatment. These tasks are strongly dependent on imaging technologies. Among these, computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US) and positron emission tomography (PET) have been applied in high-precision RT. For tumour volume delineation and characterization, PET has brought an additional dimension to the management of cancer patients by allowing the incorporation of crucial functional and molecular images in RT treatment planning, i.e. direct evaluation of tumour metabolism, cell proliferation, apoptosis, hypoxia and angiogenesis. The combination of PET and CT in a single imaging system (PET/CT) to obtain a fused anatomical and functional dataset is now emerging as a promising tool in radiotherapy departments for delineation of tumour volumes and optimization of treatment plans. Another exciting new area is image-guided radiotherapy (IGRT), which focuses on the potential benefit of advanced imaging and image registration to improve precision, daily target localization and monitoring during treatment, thus reducing morbidity and potentially allowing the safe delivery of higher doses. The variety of IGRT systems is rapidly expanding, including cone beam CT and US. This article examines the increasing role of imaging techniques in the entire process of high-precision radiotherapy.

  20. Adaptive Radiotherapy for an Uncommon Chloroma

    PubMed Central

    Majdoul, Soufya; Colson-Durand, Laurianne; To, Nu Hanh; Belkacemi, Yazid

    2016-01-01

    Granulocytic sarcomas, also referred to as chloromas or myeloid sarcomas, are extramedullary neoplasms that are composed of immature myeloid cells. This uncommon disease is known to be radiosensitive. However, the total dose and dose per fraction are not standardized. In addition, during the course of radiation therapy, significant reduction of the tumor is usually obtained. Thus, target volume reduction may require an intermediate radiotherapy plan evaluation for an adaptive treatment. A second plan at mid-dose is highly recommended. PMID:27920690

  1. Low-Dose Radiotherapy in Indolent Lymphoma

    SciTech Connect

    Rossier, Christine; Schick, Ulrike; Miralbell, Raymond; Mirimanoff, Rene O.; Weber, Damien C.; Ozsahin, Mahmut

    2011-11-01

    Purpose: To assess the response rate, duration of response, and overall survival after low-dose involved-field radiotherapy in patients with recurrent low-grade lymphoma or chronic lymphocytic leukemia (CLL). Methods and Materials: Forty-three (24 women, 19 men) consecutive patients with indolent lymphoma or CLL were treated with a total dose of 4 Gy (2 x 2 Gy) using 6- 18-MV photons. The median age was 73 years (range, 39-88). Radiotherapy was given either after (n = 32; 75%) or before (n = 11; 25%) chemotherapy. The median time from diagnosis was 48 months (range, 1-249). The median follow-up period was 20 months (range, 1-56). Results: The overall response rate was 90%. Twelve patients (28%) had a complete response, 15 (35%) had a partial response, 11 (26%) had stable disease, and 5 (11%) had progressive disease. The median overall survival for patients with a positive response (complete response/partial response/stable disease) was 41 months; for patients with progressive disease it was 6 months (p = 0.001). The median time to in-field progression was 21 months (range, 0-24), and the median time to out-field progression was 8 months (range, 0-40). The 3-year in-field control was 92% in patients with complete response (median was not reached). The median time to in-field progression was 9 months (range, 0.5-24) in patients with partial response and 6 months (range, 0.6-6) in those with stable disease (p < 0.05). Younger age, positive response to radiotherapy, and no previous chemotherapy were the best factors influencing the outcome. Conclusions: Low-dose involved-field radiotherapy is an effective treatment in the management of patients with recurrent low-grade lymphoma or CLL.

  2. Radiation transport in a radiotherapy room

    SciTech Connect

    Agosteo, S.; Para, A.F.; Maggioni, B.

    1995-01-01

    The photoneutron dose equivalent in a linac radio-therapy room and its entrance maze was investigated by means of Monte Carlo simulations under different conditions. Particularly, the effect of neutron absorbers and moderator layers placed on the maze walls was considered. The contribution of prompt gamma rays emitted in absorption reactions of thermal neutrons was also taken into account. The simulation results are compared with some experimental measurements in the therapy room and in the maze. 13 refs., 5 figs., 5 tabs.

  3. Glioblastoma multiforme after radiotherapy for acromegaly

    SciTech Connect

    Piatt, J.H. Jr.; Blue, J.M.; Schold, S.C. Jr.; Burger, P.C.

    1983-07-01

    A case of glioblastoma multiforme that occurred 14 years after radiotherapy for acromegaly is presented. The striking correspondence between the anatomy of the tumor and the geometry of the radiation ports is suggestive of a causal relationship. Previously reported cases of radiation-associated glioma are reviewed, and a brief appraisal of the evidence for induction of these lesions by radiation is presented. The differentiation of radiation-associated neoplasms from radionecrosis is also discussed.

  4. Radiation hepatitis following moving strip radiotherapy

    SciTech Connect

    Feigen, M.; Lavrin, L.; Mameghan, H.; Peters, L.

    1983-03-01

    A 71 year-old woman developed acute veno-occlusive disease of the liver after receiving moving strip radiotherapy to the whole abdomen according to the Toronto technique for carcinoma of the ovary. The dose of 22.5 Gy in 10 fractions to the liver is compared with other regimens which have produced this complication, and factors which may have sensitized the liver to irradiation are considered.

  5. Postoperative radiotherapy in the management of keloids

    PubMed Central

    Carvajal, Claudia C; Ibarra, Carla M; Arbulo, Douglas L; Russo, Moisés N; Solé, Claudio P

    2016-01-01

    Background The high recurrence rate following keloid resection has generated interest in adjuvant treatments for this disease. Objective This study assesses keloid recurrence when treated with surgery and adjuvant radiotherapy. Methods Retrospective analysis of resected keloids in patients referred to a Chilean radiation oncology centre between 2006 and 2013. Local recurrence was defined as new tissue growth on the surgical scar margin. Results Around103 keloids were analysed in 63 patients treated with 15 Gy in three fraction radiotherapy which was initiated on the same day as the surgery (75% of cases). The median keloid diameter was 6 cm; the most common site was thoracic (22%); the most common cause was prior surgery (35%); 37% caused symptoms, and several (47%) had received prior treatment with corticosteroids (32%), or surgery (30%). The median follow-up was three years, and 94% of recurrences occurred during the first year following treatment. Uni and multivariate analyses showed that an absence of symptoms was a protective factor for recurrence (OR: 0.24), while the time interval from onset to treatment with surgery plus radiotherapy >4.2 years was a risk factor (OR: 2.23). The first year recurrence rate was 32% and stabilised at 32% by the second year with no recurrences after 15 months. Conclusions The combination of surgery and radiotherapy proved to be a good therapeutic alternative in the management of keloids. Our results are similar to those described in the literature for a dose of 15 Gy. Given these results, our centre will implement a new dose escalation protocol to improve future outcomes. PMID:27994646

  6. The role of radiotherapy in veterinary practice.

    PubMed

    Owen, L N

    1975-11-01

    It is common knowledge today that cancer is by no means an incurable disease and therefore it is no longer necessary to propose euthanasia for all inoperable cases of malignant neoplasia. The veterinary surgeon has a duty to inform his client of current methods of treatment, particularly radiotherapy, which may possibly provide a cure or prolong life without pain for several months. This article outlines the availability and usefulness of this important line of treatment.

  7. Radiotherapy in the treatment of postoperative chylothorax

    PubMed Central

    2013-01-01

    Background Chylothorax is characterized by the presence of chyle in the pleural cavity. The healing rate of non-operative treatment varies enormously; the maximum success rate in series is 70%. We investigate the efficacy and outcomes of radiotherapy for postoperative chylothorax. Methods Chylothorax was identified based on the quantity and quality of the drainage fluid. Radiation was indicated if the daily chyle flow exceeded 450 ml after complete cessation of oral intake. Radiotherapy consisted of opposed isocentric portals to the mediastinum using 15 MV photon beams from a linear accelerator, a single dose of 1–1.5 Gy, and a maximum of five fractions per week. The radiation target area was the anatomical region between TH3 and TH10 depending on the localization of the resected lobe. The mean doses of the ionizing energy was 8.5 Gy ± 3.5 Gy. Results The median start date of the radiation was the fourth day after chylothorax diagnosis. The patients’ mediastinum was radiated an average of six times. Radiotherapy, in combination with dietary restrictions, was successful in all patients. The median time between the end of the radiation and the removal of the chest tube was one day. One patient underwent wound healing by secondary intention. The median time between the end of radiation and discharge was three days, and the overall hospital stay between the chylothorax diagnosis and discharge was 18 days (range: 11–30 days). After a follow-up of six months, no patient experienced chylothorax recurrence. Conclusions Our results suggest that radiotherapy in combination with dietary restriction in the treatment of postoperative chylothorax is very safe, rapid and successful. This novel interventional procedure can obviate repeat major thoracic surgery and shorten hospital stays and could be the first choice in the treatment of postthoracotomy chylothorax. PMID:23566741

  8. Partial breast radiotherapy with simple teletherapy techniques.

    PubMed

    Fekete, Gábor; Újhidy, Dóra; Együd, Zsófia; Kiscsatári, Laura; Marosi, Gusztáv; Kahán, Zsuzsanna; Varga, Zoltán

    2015-01-01

    A prospective pilot study of partial breast irradiation (PBI) with conventional vs hypofractionated schedules was set out. The study aimed to determine efficacy, acute and late side effects, and the preference of photon vs electron irradiation based on individual features. Patients were enrolled according to internationally accepted guidelines on PBI. Conformal radiotherapy plans were generated with both photon and electron beams, and the preferred technique based on dose homogeneity and the radiation exposure of healthy tissues was applied. For electron dose verification, a special phantom was constructed. Patients were randomized for fractionation schedules of 25 × 2 vs 13 × 3Gy. Skin and breast changes were registered at the time of and ≥1 year after the completion of radiotherapy. Dose homogeneity was better with photons. If the tumor bed was located in the inner quadrants, electron beam gave superior results regarding conformity and sparing of organ at risk (OAR). If the tumor was situated in the lateral quadrants, conformity was better with photons. A depth of the tumor bed ≥3.0cm predicted the superiority of photon irradiation (odds ratio [OR] = 23.6, 95% CI: 5.2 to 107.5, p < 0.001) with >90% sensitivity and specificity. After a median follow-up of 39 months, among 72 irradiated cases, 1 local relapse out of the tumor bed was detected. Acute radiodermatitis of grade I to II, hyperpigmentation, and telangiectasia developed ≥1 year after radiotherapy, exclusively after electron beam radiotherapy. The choice of electrons or photons for PBI should be based on tumor bed location; the used methods are efficient and feasible.

  9. Partial breast radiotherapy with simple teletherapy techniques

    SciTech Connect

    Fekete, Gábor; Újhidy, Dóra; Együd, Zsófia; Kiscsatári, Laura; Marosi, Gusztáv; Kahán, Zsuzsanna; Varga, Zoltán

    2015-01-01

    A prospective pilot study of partial breast irradiation (PBI) with conventional vs hypofractionated schedules was set out. The study aimed to determine efficacy, acute and late side effects, and the preference of photon vs electron irradiation based on individual features. Patients were enrolled according to internationally accepted guidelines on PBI. Conformal radiotherapy plans were generated with both photon and electron beams, and the preferred technique based on dose homogeneity and the radiation exposure of healthy tissues was applied. For electron dose verification, a special phantom was constructed. Patients were randomized for fractionation schedules of 25 × 2 vs 13 × 3 Gy. Skin and breast changes were registered at the time of and ≥1 year after the completion of radiotherapy. Dose homogeneity was better with photons. If the tumor bed was located in the inner quadrants, electron beam gave superior results regarding conformity and sparing of organ at risk (OAR). If the tumor was situated in the lateral quadrants, conformity was better with photons. A depth of the tumor bed ≥3.0 cm predicted the superiority of photon irradiation (odds ratio [OR] = 23.6, 95% CI: 5.2 to 107.5, p < 0.001) with >90% sensitivity and specificity. After a median follow-up of 39 months, among 72 irradiated cases, 1 local relapse out of the tumor bed was detected. Acute radiodermatitis of grade I to II, hyperpigmentation, and telangiectasia developed ≥1 year after radiotherapy, exclusively after electron beam radiotherapy. The choice of electrons or photons for PBI should be based on tumor bed location; the used methods are efficient and feasible.

  10. Medical treatment for biochemical relapse after radiotherapy.

    PubMed

    Quero, L; Hennequin, C

    2014-10-01

    This article's purpose was to review the medical data justifying the use of a medical treatment for biochemical relapse after external beam radiotherapy. The MEDLINE database was searched to identify relevant information with the following medical subject headings: "prostate cancer", "radiotherapy" and "biochemical relapse". Prognostic factors affecting the overall survival of patients with a biochemical relapse after external beam radiotherapy have been identified: short prostate specific antigen (PSA)-doubling time (< 12 months), high PSA value (> 10 ng/mL) and short interval between treatment and biochemical relapse (< 18 months). If a second local treatment is not feasible, timing to initiate a salvage medical treatment is not defined. Particularly, randomized trials did not demonstrate a significant benefit of an early initiation of androgen deprivation treatment. Some retrospective studies suggest that an early androgen deprivation is justified if poor prognostic factors are found. However, if an androgen deprivation treatment is prescribed, intermittent schedule is non-inferior to a continuous administration and seems to offer a better quality of life. Many non-hormonal treatments have also been evaluated in this setting: only 5-alpha-reductase inhibitors could be proposed in some specific situations. In conclusion, the judicious use of a medical treatment for biochemical relapse is still debated. Given the natural history of this clinical situation, a simple surveillance is justified in many cases.

  11. Proton beam radiotherapy of iris melanoma

    SciTech Connect

    Damato, Bertil . E-mail: Bertil@damato.co.uk; Kacperek, Andrzej; Chopra, Mona; Sheen, Martin A.; Campbell, Ian R.; Errington, R. Douglas

    2005-09-01

    Purpose: To report on outcomes after proton beam radiotherapy of iris melanoma. Methods and Materials: Between 1993 and 2004, 88 patients with iris melanoma received proton beam radiotherapy, with 53.1 Gy in 4 fractions. Results: The patients had a mean age of 52 years and a median follow-up of 2.7 years. The tumors had a median diameter of 4.3 mm, involving more than 2 clock hours of iris in 32% of patients and more than 2 hours of angle in 27%. The ciliary body was involved in 20%. Cataract was present in 13 patients before treatment and subsequently developed in another 18. Cataract had a 4-year rate of 63% and by Cox analysis was related to age (p = 0.05), initial visual loss (p < 0.0001), iris involvement (p < 0.0001), and tumor thickness (p < 0.0001). Glaucoma was present before treatment in 13 patients and developed after treatment in another 3. Three eyes were enucleated, all because of recurrence, which had an actuarial 4-year rate of 3.3% (95% CI 0-8.0%). Conclusions: Proton beam radiotherapy of iris melanoma is well tolerated, the main problems being radiation-cataract, which was treatable, and preexisting glaucoma, which in several patients was difficult to control.

  12. Anal Cancer: An Examination of Radiotherapy Strategies

    SciTech Connect

    Glynne-Jones, Rob; Lim, Faye

    2011-04-01

    The Radiation Therapy Oncology Group 9811, ACCORD-03, and ACT II Phase III trials in anal cancer showed no benefit for cisplatin-based induction and maintenance chemotherapy, or radiation dose-escalation >59 Gy. This review examines the efficacy and toxicity of chemoradiation (CRT) in anal cancer, and discusses potential alternative radiotherapy strategies. The evidence for the review was compiled from randomized and nonrandomized trials of radiation therapy and CRT. A total of 103 retrospective/observational studies, 4 Phase I/II studies, 16 Phase II prospective studies, 2 randomized Phase II studies, and 6 Phase III trials of radiotherapy or chemoradiation were identified. There are no meta-analyses based on individual patient data. A 'one-size-fits-all' approach for all stages of anal cancer is inappropriate. Early T1 tumors are probably currently overtreated, whereas T3/T4 lesions might merit escalation of treatment. Intensity-modulated radiotherapy or the integration of biological therapy may play a role in future.

  13. Functional MRI for radiotherapy of gliomas.

    PubMed

    Chang, Jenghwa; Narayana, Ashwatha

    2010-08-01

    In this paper, we review the applications of functional magnetic resonance imaging (MRI) for target delineation and critical organ avoidance for brain radiotherapy. In this article we distinguish functional MRI from brain functional MRI (fMRI). Functional MRI includes magnetic resonance spectroscopic imaging (MRSI), perfusion MRI, diffusion tensor imaging (DTI) and brain fMRI. These functional MRI modalities can provide unique metabolic, pathological and physiological information that are not available in anatomic MRI and can potentially improve the treatment outcomes of brain tumors. For example, both choline (Cho) to N-acetylaspartate (NAA) and Cho to creatine (Cr) ratios from MRSI increase with increasing tumor malignancy and can be used to grade gliomas. Relative cerebral blood volume (rCBV) measurements from dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC MRI) are superior to conventional contrast-enhanced MRI in predicting tumor biology and may be even superior to pathologic assessment in predicting patient clinical outcomes. Brain fMRI can help identify and avoid functionally critical areas when constructing treatment plans for brain radiotherapy. In the past, functional MRI measurements have not been routinely used in a clinical arena due to the experimental nature of these imaging modalities. As these methods become more commonly used and effective image co-registration algorithms become available, integration of functional MRI into the treatment process of brain radiotherapy now appears to be clinically feasible, at least in major medical centers.

  14. [Bronchiolitis obliterans organizing pneumonia following radiotherapy].

    PubMed

    Petit, Sandrine; Lortholary, Alain; Troussier, Jacques; Tuchais, Claude

    2005-04-09

    Pulmonary complications of radiotherapy are rare, but bronchiolitis obliterans organizing pneumonia (BOOP) is observed in 2.5% of cases. It can develop after radiation treatment of breast cancer as well as, more rarely, lung cancer, sarcoma, Hodgkin's disease or malignant thymoma. Ten months after radiotherapy for breast cancer, a 52 year-old woman developed migratory alveolar opacities outside the radiation field. Their improvement with corticosteroid treatment led to the diagnosis of BOOP. BOOP, which resembles infectious pneumonia, can develop 2-7 months after the end of radiotherapy and is seen especially in women aged 50-60 years with fever and coughs resistant to antibiotics. Dyspnea is far rarer. Imaging reveals patchy infiltrates with widespread bilateral, mobile lesions extended over and above the radiation field. Biopsy is required to confirm diagnosis; sections, which may or may not come from the radiation field, reveal the nonspecific granulomatous alveolar infiltrates typical of BOOP. Other causes should be eliminated (toxic, immune, iatrogenic or even idiopathic infection and recurrent early neoplastic relapse). Association with hormone therapy does not influence the course of BOOP. Outcome with corticosteroid treatment is excellent.

  15. Gold nanoparticle hyperthermia reduces radiotherapy dose.

    PubMed

    Hainfeld, James F; Lin, Lynn; Slatkin, Daniel N; Avraham Dilmanian, F; Vadas, Timothy M; Smilowitz, Henry M

    2014-11-01

    Gold nanoparticles can absorb near infrared light, resulting in heating and ablation of tumors. Gold nanoparticles have also been used for enhancing the X-ray dose to tumors. The combination of hyperthermia and radiotherapy is synergistic, importantly allowing a reduction in X-ray dose with improved therapeutic results. Here we intratumorally infused small 15 nm gold nanoparticles engineered to be transformed from infrared-transparent to infrared-absorptive by the tumor, then heated by infrared followed by X-ray treatment. Synergy was studied using a very radioresistant subcutaneous squamous cell carcinoma (SCCVII) in mice. It was found that the dose required to control 50% of the tumors, normally 55 Gy, could be reduced to <15 Gy (a factor of >3.7). Gold nanoparticles therefore provide a method to combine hyperthermia and radiotherapy to drastically reduce the X-ray radiation needed, thus sparing normal tissue, reducing side effects, and making radiotherapy more effective. Gold nanoparticles are known to enhance the efficacy of X-ray in tumor irradiation resulting in tumor heating and ablation. They also absorb near infrared light. This dual property was studied using a very radioresistant subcutaneous squamous cell carcinoma in mice, demonstrating that the dose required to control 50% of the tumors could be reduced by a factor of > 3.7, paving the way to potential future clinical applications. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Personalized radiotherapy: concepts, biomarkers and trial design.

    PubMed

    Ree, A H; Redalen, K R

    2015-07-01

    In the past decade, and pointing onwards to the immediate future, clinical radiotherapy has undergone considerable developments, essentially including technological advances to sculpt radiation delivery, the demonstration of the benefit of adding concomitant cytotoxic agents to radiotherapy for a range of tumour types and, intriguingly, the increasing integration of targeted therapeutics for biological optimization of radiation effects. Recent molecular and imaging insights into radiobiology will provide a unique opportunity for rational patient treatment, enabling the parallel design of next-generation trials that formally examine the therapeutic outcome of adding targeted drugs to radiation, together with the critically important assessment of radiation volume and dose-limiting treatment toxicities. In considering the use of systemic agents with presumed radiosensitizing activity, this may also include the identification of molecular, metabolic and imaging markers of treatment response and tolerability, and will need particular attention on patient eligibility. In addition to providing an overview of clinical biomarker studies relevant for personalized radiotherapy, this communication will highlight principles in addressing clinical evaluation of combined-modality-targeted therapeutics and radiation. The increasing number of translational studies that bridge large-scale omics sciences with quality-assured phenomics end points-given the imperative development of open-source data repositories to allow investigators the access to the complex data sets-will enable radiation oncology to continue to position itself with the highest level of evidence within existing clinical practice.

  17. Personalized radiotherapy: concepts, biomarkers and trial design

    PubMed Central

    Redalen, K R

    2015-01-01

    In the past decade, and pointing onwards to the immediate future, clinical radiotherapy has undergone considerable developments, essentially including technological advances to sculpt radiation delivery, the demonstration of the benefit of adding concomitant cytotoxic agents to radiotherapy for a range of tumour types and, intriguingly, the increasing integration of targeted therapeutics for biological optimization of radiation effects. Recent molecular and imaging insights into radiobiology will provide a unique opportunity for rational patient treatment, enabling the parallel design of next-generation trials that formally examine the therapeutic outcome of adding targeted drugs to radiation, together with the critically important assessment of radiation volume and dose-limiting treatment toxicities. In considering the use of systemic agents with presumed radiosensitizing activity, this may also include the identification of molecular, metabolic and imaging markers of treatment response and tolerability, and will need particular attention on patient eligibility. In addition to providing an overview of clinical biomarker studies relevant for personalized radiotherapy, this communication will highlight principles in addressing clinical evaluation of combined-modality-targeted therapeutics and radiation. The increasing number of translational studies that bridge large-scale omics sciences with quality-assured phenomics end points—given the imperative development of open-source data repositories to allow investigators the access to the complex data sets—will enable radiation oncology to continue to position itself with the highest level of evidence within existing clinical practice. PMID:25989697

  18. Single crystal diamond detector for radiotherapy

    NASA Astrophysics Data System (ADS)

    Schirru, F.; Kisielewicz, K.; Nowak, T.; Marczewska, B.

    2010-07-01

    The new generation of synthetic diamonds grown as a CVD single crystal on a high pressure high temperature substrate offers a wide range of applications. In particular, because of the near tissue equivalence and its small size (good spatial resolution), CVD single crystal diamond finds applicability in radiotherapy as a dosemeter of ionizing radiation. In this paper we report the electrical and dosimetric properties of a new diamond detector which was fabricated at IFJ based on a single crystal detector-grade CVD diamond provided with a novel contact metallization. Diamond properties were assessed at IFJ using a Theratron 680E therapeutic 60Co gamma rays unit and at COOK with 6 and 18 MV x-rays Varian Clinac CL2300 C/D accelerator. The new dosemeter showed high electric and dosimetric performances: low value of dark current, high current at the level of some nanoamperes during irradiation, very fast dynamic response with a rise time amounting to parts of a second, good stability and repeatability of the current and linearity of the detector signal at different dose and dose rate levels typically applied in radiotherapy. The results confirm the potential applicability of diamond material as a dosemeter for applications in radiotherapy.

  19. Big Data Analytics for Prostate Radiotherapy.

    PubMed

    Coates, James; Souhami, Luis; El Naqa, Issam

    2016-01-01

    Radiation therapy is a first-line treatment option for localized prostate cancer and radiation-induced normal tissue damage are often the main limiting factor for modern radiotherapy regimens. Conversely, under-dosing of target volumes in an attempt to spare adjacent healthy tissues limits the likelihood of achieving local, long-term control. Thus, the ability to generate personalized data-driven risk profiles for radiotherapy outcomes would provide valuable prognostic information to help guide both clinicians and patients alike. Big data applied to radiation oncology promises to deliver better understanding of outcomes by harvesting and integrating heterogeneous data types, including patient-specific clinical parameters, treatment-related dose-volume metrics, and biological risk factors. When taken together, such variables make up the basis for a multi-dimensional space (the "RadoncSpace") in which the presented modeling techniques search in order to identify significant predictors. Herein, we review outcome modeling and big data-mining techniques for both tumor control and radiotherapy-induced normal tissue effects. We apply many of the presented modeling approaches onto a cohort of hypofractionated prostate cancer patients taking into account different data types and a large heterogeneous mix of physical and biological parameters. Cross-validation techniques are also reviewed for the refinement of the proposed framework architecture and checking individual model performance. We conclude by considering advanced modeling techniques that borrow concepts from big data analytics, such as machine learning and artificial intelligence, before discussing the potential future impact of systems radiobiology approaches.

  20. Sacral plexus injury after radiotherapy for carcinoma of cervix

    SciTech Connect

    Stryker, J.A.; Sommerville, K.; Perez, R.; Velkley, D.E. )

    1990-10-01

    A 42-year-old woman developed lower extremity weakness and sensory loss 1 year after external and intracavitary radiotherapy for Stage IB carcinoma of cervix. She has been followed for 5 years posttreatment, and the neurologic abnormalities have persisted, but no evidence of recurrent carcinoma has been found. We believe this to be a rare case of sacral plexus radiculopathy developing as a late complication after radiotherapy. Suggestions are made for improving the radiotherapy technique to prevent this complication in future cases.

  1. Errors in radiotherapy: motivation for development of new radiotherapy quality assurance paradigms.

    PubMed

    Fraass, Benedick A

    2008-01-01

    Modern radiotherapy practice has rapidly evolved during the past decade, making use of many highly complex and/or automated processes for planning and delivery, including new techniques, like intensity-modulated radiotherapy driven by inverse planning optimization methods, or near real-time image-guided adaptive therapy based on fluoroscopic or tomographic imaging on the treatment machine. In spite of the modern technology, or potentially because of it in some instances, errors and other problems continue to have a significant impact on the field. This report reviews example errors and problems, discusses some of the quality assurance issues that these types of problems raise, and motivates the development of more modern and sophisticated approaches to assure quality for our clinical radiotherapy treatment methods.

  2. Radical hysterectomy with adjuvant radiotherapy versus radical radiotherapy for FIGO stage IIB cervical cancer

    PubMed Central

    2014-01-01

    Background The goal of this study was to compare treatment outcomes for Federation of Gynecology and Obstetrics (FIGO) stage IIB cervical carcinoma patients receiving radical surgery followed by adjuvant postoperative radiotherapy versus radical radiotherapy. Methods Medical records of FIGO stage IIB cervical cancer patients treated between July 2008 and December 2011 were retrospectively reviewed. A total of 148 patients underwent radical hysterectomy with pelvic lymph node dissection followed by adjuvant radiotherapy (surgery-based group). These patients were compared with 290 patients that received radical radiotherapy alone (RT-based group). Recurrence rates, progression-free survival (PFS), overall survival (OS), local control rates, and treatment-related complications were compared for these two groups. Results Similar rates of recurrence (16.89% vs. 12.41%, p = 0.200), PFS (log-rank, p = 0.211), OS (log-rank, p = 0.347), and local control rates (log-rank, p = 0.668) were observed for the surgery-based group and the RT-based group, respectively. Moreover, the incidence of acute grade 3–4 gastrointestinal reactions and late grade 3–4 lower limb lymphedema were significantly higher for the surgery-based group versus the RT-based group. Cox multivariate analyses found no significant difference in survival outcome between the two groups, and tumor diameter and histopathology were identified as significant prognostic factors for OS. Conclusions Radical radiotherapy was associated with fewer treatment-related complications and achieved comparable survival outcomes for patients with FIGO stage IIB cervical cancer compared to radical hysterectomy followed by postoperative radiotherapy. PMID:24495453

  3. Genome-wide transcription responses to synchrotron microbeam radiotherapy.

    PubMed

    Sprung, Carl N; Yang, Yuqing; Forrester, Helen B; Li, Jason; Zaitseva, Marina; Cann, Leonie; Restall, Tina; Anderson, Robin L; Crosbie, Jeffrey C; Rogers, Peter A W

    2012-10-01

    The majority of cancer patients achieve benefit from radiotherapy. A significant limitation of radiotherapy is its relatively low therapeutic index, defined as the maximum radiation dose that causes acceptable normal tissue damage to the minimum dose required to achieve tumor control. Recently, a new radiotherapy modality using synchrotron-generated X-ray microbeam radiotherapy has been demonstrated in animal models to ablate tumors with concurrent sparing of normal tissue. Very little work has been undertaken into the cellular and molecular mechanisms that differentiate microbeam radiotherapy from broad beam. The purpose of this study was to investigate and compare the whole genome transcriptional response of in vivo microbeam radiotherapy versus broad beam irradiated tumors. We hypothesized that gene expression changes after microbeam radiotherapy are different from those seen after broad beam. We found that in EMT6.5 tumors at 4-48 h postirradiation, microbeam radiotherapy differentially regulates a number of genes, including major histocompatibility complex (MHC) class II antigen gene family members, and other immunity-related genes including Ciita, Ifng, Cxcl1, Cxcl9, Indo and Ubd when compared to broad beam. Our findings demonstrate molecular differences in the tumor response to microbeam versus broad beam irradiation and these differences provide insight into the underlying mechanisms of microbeam radiotherapy and broad beam.

  4. Biomarkers for DNA DSB inhibitors and radiotherapy clinical trials.

    PubMed

    Liu, Stanley K; Olive, Peggy L; Bristow, Robert G

    2008-09-01

    Major technical advances in radiotherapy, including IMRT and image-guided radiotherapy, have allowed for improved physical precision and increased dose delivery to the tumor, with better sparing of surrounding normal tissue. The development of inhibitors of the sensing and repair of DNA double-strand breaks (DSBs) is exciting and could be combined with precise radiotherapy targeting to improve local control following radiotherapy. However, caution must be exercised in order that DSB inhibitors are combined with radiotherapy in such a manner as to preserve the therapeutic ratio by exploiting repair deficiencies in malignant cells over that of normal cells. In this review, we discuss the rationale and current approaches to targeting DSB sensing and repair pathways in combined modality with radiotherapy. We also describe potential biomarkers that could be useful in detecting functional inhibition of DSB repair in a patient's tissues during clinical radiotherapy trials. Finally, we examine a number of issues relating to the use of DSB-inhibiting molecular agents and radiotherapy in the context of the tumor microenvironment, effects on normal tissues and the optimal timing and duration of the agent in relation to fractionated radiotherapy.

  5. Proton Radiotherapy for Liver Tumors: Dosimetric Advantages Over Photon Plans

    SciTech Connect

    Wang Xiaochun Krishnan, Sunil; Zhang Xiaodong; Dong Lei; Briere, Tina; Crane, Christopher H.; Martel, Mary; Gillin, Michael; Mohan, Radhe; Beddar, Sam

    2008-01-01

    The purpose of the study is to dosimetrically investigate the advantages of proton radiotherapy over photon radiotherapy for liver tumors. The proton plan and the photon plan were designed using commercial treatment planning systems. The treatment target dose conformity and heterogeneity and dose-volume analyses of normal structures were compared between proton and photon radiotherapy for 9 patients with liver tumors. Proton radiotherapy delivered a more conformal target dose with slightly less homogeneity when compared with photon radiotherapy. Protons significantly reduced the fractional volume of liver receiving dose greater or equal to 30 Gy (V{sub 30}) and the mean liver dose. The stomach and duodenal V{sub 45} were significantly lower with the use of proton radiotherapy. The V{sub 40} and V{sub 50} of the heart and the maximum spinal cord dose were also significantly lower with the use of proton radiotherapy. Protons were better able to spare one kidney completely and deliver less dose to one (generally the left) kidney than photons. The mean dose to the total body and most critical structures was significantly decreased using protons when compared to corresponding photon plans. In conclusion, our study suggests the dosimetric benefits of proton radiotherapy over photon radiotherapy. These dosimetric advantages of proton plans may permit further dose escalation with lower risk of complications.

  6. Dysphagia after radiotherapy: state of the art and prevention.

    PubMed

    Servagi-Vernat, S; Ali, D; Roubieu, C; Durdux, C; Laccourreye, O; Giraud, P

    2015-02-01

    Adjuvant radiotherapy after surgery or exclusive radiotherapy, with or without concurrent chemotherapy is a valuable treatment option in the great majority of patients with head and neck cancer. Recent technical progress in radiotherapy has resulted in a decreased incidence of xerostomia. Another common toxicity of radiotherapy is dysphagia, which alters the nutritional status and quality of life of patients in remission. The objective of this review is to describe the physiology of swallowing function, the pathophysiology of radiation-induced dysphagia and the various strategies currently available to prevent this complication.

  7. Dynamic targeting image-guided radiotherapy

    SciTech Connect

    Huntzinger, Calvin; Munro, Peter; Johnson, Scott; Miettinen, Mika; Zankowski, Corey; Ahlstrom, Greg; Glettig, Reto; Filliberti, Reto; Kaissl, Wolfgang; Kamber, Martin; Amstutz, Martin; Bouchet, Lionel; Klebanov, Dan; Mostafavi, Hassan; Stark, Richard

    2006-07-01

    Volumetric imaging and planning for 3-dimensional (3D) conformal radiotherapy and intensity-modulated radiotherapy (IMRT) have highlighted the need to the oncology community to better understand the geometric uncertainties inherent in the radiotherapy delivery process, including setup error (interfraction) as well as organ motion during treatment (intrafraction). This has ushered in the development of emerging technologies and clinical processes, collectively referred to as image-guided radiotherapy (IGRT). The goal of IGRT is to provide the tools needed to manage both inter- and intrafraction motion to improve the accuracy of treatment delivery. Like IMRT, IGRT is a process involving all steps in the radiotherapy treatment process, including patient immobilization, computed tomogaphy (CT) simulation, treatment planning, plan verification, patient setup verification and correction, delivery, and quality assurance. The technology and capability of the Dynamic Targeting{sup TM} IGRT system developed by Varian Medical Systems is presented. The core of this system is a Clinac (registered) or Trilogy{sup TM} accelerator equipped with a gantry-mounted imaging system known as the On-Board Imager{sup TM} (OBI). This includes a kilovoltage (kV) x-ray source, an amorphous silicon kV digital image detector, and 2 robotic arms that independently position the kV source and imager orthogonal to the treatment beam. A similar robotic arm positions the PortalVision{sup TM} megavoltage (MV) portal digital image detector, allowing both to be used in concert. The system is designed to support a variety of imaging modalities. The following applications and how they fit in the overall clinical process are described: kV and MV planar radiographic imaging for patient repositioning, kV volumetric cone beam CT imaging for patient repositioning, and kV planar fluoroscopic imaging for gating verification. Achieving image-guided motion management throughout the radiation oncology process

  8. Chest wall desmoid tumours treated with definitive radiotherapy: a plan comparison of 3D conformal radiotherapy, intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy.

    PubMed

    Liu, Jia; Ng, Diana; Lee, James; Stalley, Paul; Hong, Angela

    2016-03-02

    Definitive radiotherapy is often used for chest wall desmoid tumours due to size or anatomical location. The delivery of radiotherapy is challenging due to the large size and constraints of normal surrounding structures. We compared the dosimetry of 3D conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) to evaluate the best treatment option. Ten consecutive patients with inoperable chest wall desmoid tumours (PTV range 416-4549 cm(3)) were selected. For each patient, 3DCRT, IMRT and VMAT plans were generated and the Conformity Index (CI), organ at risk (OAR) doses and monitor unit (MU) were evaluated. The Wilcoxon signed-rank test was used to compare dose delivered to both target and OARs. The mean number of fields for 3DCRT and IMRT were 6.3 ± 2.1, 7.2 ± 1.8. The mean number of arcs for VMAT was 3.7 ± 1.1. The mean conformity index of VMAT (0.98 ± 0.14) was similar to that of IMRT (1.03 ± 0.13), both of which were significantly better than 3DCRT (1.35 ± 0.20; p = 0.005). The mean dose to lung was significantly higher for 3DCRT (11.9Gy ± 7.9) compared to IMRT (9.4Gy ± 5.4, p = 0.014) and VMAT (8.9Gy ± 4.5, p = 0.017). For the 3 females, the low dose regions in the ipsilateral breast for VMAT were generally less with VMAT. IMRT plans required 1427 ± 532 MU per fraction which was almost 4-fold higher than 3DCRT (313 ± 112, P = 0.005). Compared to IMRT, VMAT plans required 60 % less MU (570 ± 285, P = 0.005). For inoperable chest wall desmoid tumours, VMAT delivered equivalent target coverage when compared to IMRT but required 60 % less MU. Both VMAT and IMRT were superior to 3DCRT in terms of better PTV coverage and sparing of lung tissue.

  9. Palliative radiotherapy practice within Western European countries: impact of the radiotherapy financing system?

    PubMed

    Lievens, Y; Van den Bogaert, W; Rijnders, A; Kutcher, G; Kesteloot, K

    2000-09-01

    To analyze the reimbursement modalities for radiotherapy in the different Western European countries, as well as to investigate if these differences have an impact on the palliative radiotherapy practice for bone metastases. A questionnaire was sent to 565 radiotherapy centres included in the 1997 ESTRO directory. In this questionnaire the reimbursement strategy applied in the different centres was assessed, with respect to the use of a budget (departmental or hospital budget), case payment and/or fee-for-service reimbursement. The differences were analyzed according to country and to type and size of the radiotherapy centre. A total of 170 centres (86% of the responders) returned the questionnaire. Most frequent is budget reimbursement: some form of budget reimbursement is found in 69% of the centres, whereas 46% of the centres are partly reimbursed through fee-for-service and 35% through case payment. The larger the department, the more frequent the reimbursement through a budget or a case payment system and the less the importance of fee-for-service reimbursement (chi(2): P=0.0012; logit: P=0.0055). Whereas private centres are almost equally reimbursed by fee-for-service financing as by budget or case payment, radiotherapy departments in university hospitals receive the largest part of their financial resources through a budget or by case payment (83%) (chi(2): P=0.002; logit: P=0.0073). A correlation between the country and the radiotherapy reimbursement system was also demonstrated (P=0.002), radiotherapy centres in Spain, the Netherlands and the United Kingdom being almost entirely reimbursed through a budget and/or case payment and centres in Germany and Switzerland mostly through a fee-for-service system. In budget and case payment financing lower total number of fractions and lower total dose (chi(2): P=0.003; logit: P=0.0120) as well as less shielding blocks (chi(2): P=0.003; logit: P=0.0066) are used. A same tendency is found for the use of isodose

  10. Effectiveness of Radiotherapy for Elderly Patients With Glioblastoma

    SciTech Connect

    Scott, Jacob; Tsai, Ya-Yu; Chinnaiyan, Prakash; Yu, Hsiang-Hsuan Michael

    2011-09-01

    Purpose: Radiotherapy plays a central role in the definitive treatment of glioblastoma. However, the optimal management of elderly patients with glioblastoma remains controversial, as the relative benefit in this patient population is unclear. To better understand the role that radiation plays in the treatment of glioblastoma in the elderly, we analyzed factors influencing patient survival using a large population-based registry. Methods and Materials: A total of 2,836 patients more than 70 years of age diagnosed with glioblastoma between 1993 and 2005 were identified from the Surveillance, Epidemiology, and End Results (SEER) registry. Demographic and clinical variables used in the analysis included gender, ethnicity, tumor size, age at diagnosis, surgery, and radiotherapy. Cancer-specific survival and overall survival were evaluated using the Kaplan-Meier method. Univariate and multivariate analysis were performed using Cox regression. Results: Radiotherapy was administered in 64% of these patients, and surgery was performed in 68%. Among 2,836 patients, 46% received surgery and radiotherapy, 22% underwent surgery only, 18% underwent radiotherapy only, and 14% did not undergo either treatment. The median survival for patients who underwent surgery and radiotherapy was 8 months. The median survival for patients who underwent radiotherapy only was 4 months, and for patients who underwent surgery only was 3 months. Those who received neither surgery nor radiotherapy had a median survival of 2 months (p < 0.001). Multivariate analysis showed that radiotherapy significantly improved cancer-specific survival (hazard ratio [HR], 0.43, 95% confidence interval [CI] 0.38-0.49) after adjusting for surgery, tumor size, gender, ethnicity, and age at diagnosis. Other factors associated with Cancer-specific survival included surgery, tumor size, age at diagnosis, and ethnicity. Analysis using overall survival as the endpoint yielded very similar results. Conclusions: Elderly

  11. External beam radiotherapy for unresectable hepatocellular carcinoma.

    PubMed

    Abdel-Rahman, Omar; Elsayed, Zeinab

    2017-03-07

    Hepatocellular carcinoma is the most common liver neoplasm, the sixth most common cancer worldwide, and the third most common cause of cancer mortality. Moreover, its incidence has increased dramatically in the past decade. While surgical resection and liver transplantation are the main curative treatments, only around 20% of people with early hepatocellular carcinoma may benefit from these therapies. Current treatment options for unresectable hepatocellular carcinoma include various ablative and transarterial therapies in addition to the drug sorafenib. To assess the benefits and harms of external beam radiotherapy in the management of localised unresectable hepatocellular carcinoma. We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (OvidSP), Embase (OvidSP), Science Citation Index Expanded (Web of Science), and clinicaltrials.gov registry. We also checked reference lists of primary original studies and review articles manually for further related articles (cross-references) up to October 6, 2016. Eligible studies included all randomised clinical trials comparing external beam radiotherapy either as a monotherapy or in combination with other systemic or locoregional therapies versus placebo, no treatment, or other systemic or locoregional therapies for people with unresectable hepatocellular carcinoma. We used standard methodological procedures expected by Cochrane. We used a random-effects model as well as a fixed-effect model meta-analysis but in case of discrepancy between the two models (e.g. one giving a significant intervention effect, the other no significant intervention effect), we reported both results; otherwise, we reported only the results from the fixed-effect model meta-analysis. We assessed risk of bias of the included trials using predefined risk of bias domains; assessed risks of random errors with Trial Sequential Analysis; and

  12. Children Undergoing Radiotherapy: Swedish Parents' Experiences and Suggestions for Improvement.

    PubMed

    Ångström-Brännström, Charlotte; Engvall, Gunn; Mullaney, Tara; Nilsson, Kristina; Wickart-Johansson, Gun; Svärd, Anna-Maja; Nyholm, Tufve; Lindh, Jack; Lindh, Viveca

    2015-01-01

    Approximately 300 children, from 0 to 18 years old, are diagnosed with cancer in Sweden every year. Of these children, 80-90 of them undergo radiotherapy treatment for their cancer. Although radiotherapy is an encounter with advanced technology, few studies have investigated the child's and the parent's view of the procedure. As part of an ongoing multicenter study aimed to improve patient preparation and the care environment in pediatric radiotherapy, this article reports the findings from interviews with parents at baseline. The aim of the present study was twofold: to describe parents' experience when their child undergoes radiotherapy treatment, and to report parents' suggestions for improvements during radiotherapy for their children. Sixteen mothers and sixteen fathers of children between 2-16 years old with various cancer diagnoses were interviewed. Data were analyzed using content analysis. The findings showed that cancer and treatment turns people's lives upside down, affecting the entire family. Further, the parents experience the child's suffering and must cope with intense feelings. Radiotherapy treatment includes preparation by skilled and empathetic staff. The parents gradually find that they can deal with the process; and lastly, parents have suggestions for improvements during the radiotherapy treatment. An overarching theme emerged: that despair gradually turns to a sense of security, with a sustained focus on and close interaction with the child. In conclusion, an extreme burden was experienced around the start of radiotherapy, though parents gradually coped with the process.

  13. Children Undergoing Radiotherapy: Swedish Parents’ Experiences and Suggestions for Improvement

    PubMed Central

    Mullaney, Tara; Nilsson, Kristina; Wickart-Johansson, Gun; Svärd, Anna-Maja; Nyholm, Tufve; Lindh, Jack; Lindh, Viveca

    2015-01-01

    Approximately 300 children, from 0 to 18 years old, are diagnosed with cancer in Sweden every year. Of these children, 80–90 of them undergo radiotherapy treatment for their cancer. Although radiotherapy is an encounter with advanced technology, few studies have investigated the child’s and the parent’s view of the procedure. As part of an ongoing multicenter study aimed to improve patient preparation and the care environment in pediatric radiotherapy, this article reports the findings from interviews with parents at baseline. The aim of the present study was twofold: to describe parents’ experience when their child undergoes radiotherapy treatment, and to report parents’ suggestions for improvements during radiotherapy for their children. Sixteen mothers and sixteen fathers of children between 2–16 years old with various cancer diagnoses were interviewed. Data were analyzed using content analysis. The findings showed that cancer and treatment turns people’s lives upside down, affecting the entire family. Further, the parents experience the child’s suffering and must cope with intense feelings. Radiotherapy treatment includes preparation by skilled and empathetic staff. The parents gradually find that they can deal with the process; and lastly, parents have suggestions for improvements during the radiotherapy treatment. An overarching theme emerged: that despair gradually turns to a sense of security, with a sustained focus on and close interaction with the child. In conclusion, an extreme burden was experienced around the start of radiotherapy, though parents gradually coped with the process. PMID:26509449

  14. Optimal radiotherapy utilisation rate in developing countries: An IAEA study.

    PubMed

    Rosenblatt, Eduardo; Barton, Michael; Mackillop, William; Fidarova, Elena; Cordero, Lisbeth; Yarney, Joel; Lim, Gerard; Abad, Anthony; Cernea, Valentin; Stojanovic-Rundic, Suzana; Strojan, Primoz; Kobachi, Lotfi; Quarneti, Aldo

    2015-07-01

    Optimal radiotherapy utilisation rate (RTU) is the proportion of all cancer cases that should receive radiotherapy. Optimal RTU was estimated for 9 Middle Income Countries as part of a larger IAEA project to better understand RTU and stage distribution. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Updates on clinical studies of selenium supplementation in radiotherapy

    PubMed Central

    2014-01-01

    To establish guidelines for the selenium supplementation in radiotherapy we assessed the benefits and risks of selenium supplementation in radiotherapy. Clinical studies on the use of selenium in radiotherapy were searched in the PubMed electronic database in January 2013. Sixteen clinical studies were identified among the 167 articles selected in the initial search. Ten articles were observational studies, and the other 6 articles reported studies on the effects of selenium supplementation in patients with cancer who underwent radiotherapy. The studies were conducted worldwide including European, American and Asian countries between 1987 and 2012. Plasma, serum or whole blood selenium levels were common parameters used to assess the effects of radiotherapy and the selenium supplementation status. Selenium supplementation improved the general conditions of the patients, improved their quality of life and reduced the side effects of radiotherapy. At the dose of selenium used in these studies (200–500 μg/day), selenium supplementation did not reduce the effectiveness of radiotherapy, and no toxicities were reported. Selenium supplementation may offer specific benefits for several types of cancer patients who undergo radiotherapy. Because high-dose selenium and long-term supplementation may be unsafe due to selenium toxicity, more evidence-based information and additional research are needed to ensure the therapeutic benefits of selenium supplementation. PMID:24885670

  16. Presternal soft tissue calcifications following mediastinal radiotherapy for Hodgkin's disease

    SciTech Connect

    Vainright, J.R.; Diaconis, J.N.; Haney, P.J.

    1987-01-01

    A patient is described in whom dense calcifications developed in the presternal soft tissues of the chest four years after mediastinal radiotherapy. This is believed to represent dystrophic calcification in previously normal but incidentally radiated tissues following standard dose radiotherapy to the mediastinum for stage IIA Hodgkin's disease.

  17. Radiotherapy and breast reconstruction: oncology, cosmesis and complications

    PubMed Central

    Ashton, Mark W

    2012-01-01

    Breast reconstruction plays a highly important role in the management of patients with breast cancer, from a psycho-social and sexual stand-point. Given that immediate breast reconstruction does not impair the oncologic safety of breast cancer management, with no increase in local recurrence rates, and no delays in the initiation of adjuvant chemotherapy or radiotherapy, the need to balance cosmesis in reconstruction with the oncologic needs of breast cancer patients is no more evident than in the discussion of radiotherapy. Radiotherapy is essential adjuvant therapy in the treatment of breast cancer, with the use of adjuvant radiotherapy widely shown to reduce local recurrence after both partial and total mastectomy and shown to prolong both disease-free and overall survival in patients with nodal disease. In the setting of breast reconstruction, the effects of radiotherapy are potentially two-fold, with consideration required of the impact of breast reconstruction on the administration of and the initiation of radiotherapy, as well as the effects of radiotherapy on operative complications and cosmetic outcome following immediate breast reconstruction. The current editorial piece aims to analyze this balance, contrasting both autologous and implant-based reconstruction. The literature is still evolving as to the relative role of autologous vs. alloplastic reconstruction in the setting of radiotherapy, and the more recent introduction of acellular dermal matrix and other compounds further complicate the evidence. Fat grafting and evolving techniques in breast reconstruction will herald new discussions on this front. PMID:25083434

  18. Updates on clinical studies of selenium supplementation in radiotherapy.

    PubMed

    Puspitasari, Irma M; Abdulah, Rizky; Yamazaki, Chiho; Kameo, Satomi; Nakano, Takashi; Koyama, Hiroshi

    2014-05-29

    To establish guidelines for the selenium supplementation in radiotherapy we assessed the benefits and risks of selenium supplementation in radiotherapy. Clinical studies on the use of selenium in radiotherapy were searched in the PubMed electronic database in January 2013. Sixteen clinical studies were identified among the 167 articles selected in the initial search. Ten articles were observational studies, and the other 6 articles reported studies on the effects of selenium supplementation in patients with cancer who underwent radiotherapy. The studies were conducted worldwide including European, American and Asian countries between 1987 and 2012. Plasma, serum or whole blood selenium levels were common parameters used to assess the effects of radiotherapy and the selenium supplementation status. Selenium supplementation improved the general conditions of the patients, improved their quality of life and reduced the side effects of radiotherapy. At the dose of selenium used in these studies (200-500 μg/day), selenium supplementation did not reduce the effectiveness of radiotherapy, and no toxicities were reported. Selenium supplementation may offer specific benefits for several types of cancer patients who undergo radiotherapy. Because high-dose selenium and long-term supplementation may be unsafe due to selenium toxicity, more evidence-based information and additional research are needed to ensure the therapeutic benefits of selenium supplementation.

  19. Dosimetry audit of radiotherapy treatment planning systems.

    PubMed

    Bulski, Wojciech; Chełmiński, Krzysztof; Rostkowska, Joanna

    2015-07-01

    In radiotherapy Treatment Planning Systems (TPS) various calculation algorithms are used. The accuracy of dose calculations has to be verified. Numerous phantom types, detectors and measurement methodologies are proposed to verify the TPS calculations with dosimetric measurements. A heterogeneous slab phantom has been designed within a Coordinated Research Project (CRP) of the IAEA. The heterogeneous phantom was developed in the frame of the IAEA CRP. The phantom consists of frame slabs made with polystyrene and exchangeable inhomogeneity slabs equivalent to bone or lung tissue. Special inserts allow to position thermoluminescent dosimeters (TLD) capsules within the polystyrene slabs below the bone or lung equivalent slabs and also within the lung equivalent material. Additionally, there are inserts that allow to position films or ionisation chamber in the phantom. Ten Polish radiotherapy centres (of 30 in total) were audited during on-site visits. Six different TPSs and five calculation algorithms were examined in the presence of inhomogeneities. Generally, most of the results from TLD were within 5 % tolerance. Differences between doses calculated by TPSs and measured with TLD did not exceed 4 % for bone and polystyrene equivalent materials. Under the lung equivalent material, on the beam axis the differences were lower than 5 %, whereas inside the lung equivalent material, off the beam axis, in some cases they were of around 7 %. The TLD results were confirmed with the ionisation chamber measurements. The comparison results of the calculations and the measurements allow to detect limitations of TPS calculation algorithms. The audits performed with the use of heterogeneous phantom and TLD seem to be an effective tool for detecting the limitations in the TPS performance or beam configuration errors at audited radiotherapy departments.

  20. Understanding Radiotherapy-Induced Second Cancers

    NASA Astrophysics Data System (ADS)

    Brenner, David

    2007-03-01

    There is increasing concern regarding radiation-related second-cancer risks in long-term radiotherapy survivors, and a corresponding need to be able to predict cancer risks at high radiation doses. While cancer risks at moderately low radiation doses are reasonably understood from A-bomb survivor studies, there is much more uncertainty at the high doses used in radiotherapy. It has generally been assumed that cancer induction decreases rapidly at high doses due to cell killing. However, most recent studies of radiation-induced second cancers in the lung and breast, covering a very wide range of doses, contradict this assumption. A likely resolution of this disagreement comes from considering cellular repopulation during and after radiation exposure. Repopulation / proliferation with a significant number radiation-induced pre-malignant cells, tends to counteract the effect of cell killing, and keeps the induced cancer risks higher at high doses. We describe and apply a biologically based, minimally parameterized model of dose-dependent cancer risks, incorporating carcinogenic effects, cell killing and, additionally, proliferation / repopulation effects. The situation is somewhat different for radiation-induced leukemia, as repopulation via the blood stream tends to be with cells that originated father away from the treatment volume than is the case for solid second cancers, thus containing a smaller proportion of radiation-damaged cells. The model predictions agree well with recent data on second cancer risks, both for radiation-induced solid cancers and for radiation-induced leukemias. Incorporating repopulation effects provides both a mechanistic understanding of cancer risks at high doses, as well as providing a practical methodology for predicting, and therefore potentially minimizing, cancer risks in organs exposed to high radiation doses during radiotherapy.

  1. Clinical Applications of 3-D Conformal Radiotherapy

    NASA Astrophysics Data System (ADS)

    Miralbell, Raymond

    Although a significant improvement in cancer cure (i.e. 20% increment) has been obtained in the last 2-3 decades, 30-40% of patients still fail locally after curative radiotherapy. In order to improve local tumor control rates with radiotherapy high doses to the tumor volume are frequently necessary. Three-dimensional conformal radiation therapy (3-D CRT) is used to denote a spectrum of radiation planning and delivery techniques that rely on three-dimensional imaging to define the target (tumor) and to distinguish it from normal tissues. Modern, high-precision radiotherapy (RT) techniques are needed in order to implement the goal of optimal tumor destruction delivering minimal dose to the non-target normal tissues. A better target definition is nowadays possible with contemporary imaging (computerized tomography, magnetic resonance imaging, and positron emission tomography) and image registration technology. A highly precise dose distributions can be obtained with optimal 3-D CRT treatment delivery techniques such as stereotactic RT, intensity modulated RT (IMRT), or protontherapy (the latter allowing for in-depth conformation). Patient daily set-up repositioning and internal organ immobilization systems are necessary before considering to undertake any of the above mentioned high-precision treatment approaches. Prostate cancer, brain tumors, and base of skull malignancies are among the sites most benefitting of dose escalation approaches. Nevertheless, a significant dose reduction to the normal tissues in the vicinity of the irradiated tumor also achievable with optimal 3-D CRT may also be a major issue in the treatment of pediatric tumors in order to preserve growth, normal development, and to reduce the risk of developing radiation induced diseases such as cancer or endocrinologic disorders.

  2. Our intraoperative boost radiotherapy experience and applications

    PubMed Central

    Günay, Semra; Alan, Ömür; Yalçın, Orhan; Türkmen, Aygen; Dizdar, Nihal

    2016-01-01

    Objective: To present our experience since November 2013, and case selection criteria for intraoperative boost radiotherapy (IObRT) that significantly reduces the local recurrence rate after breast conserving surgery in patients with breast cancer. Material and Methods: Patients who were suitable for IObRT were identified within the group of patients who were selected for breast conserving surgery at our breast council. A MOBETRON (mobile linear accelerator for IObRT) was used for IObRt during surgery. Results: Patients younger than 60 years old with <3 cm invasive ductal cancer in one focus (or two foci within 2 cm), with a histologic grade of 2–3, and a high possibility of local recurrence were admitted for IObRT application. Informed consent was obtained from all participants. Lumpectomy and sentinel lymph node biopsy was performed and advancement flaps were prepared according to the size and inclination of the conus following evaluation of tumor size and surgical margins by pathology. Distance to the thoracic wall was measured, and a radiation oncologist and radiation physicist calculated the required dose. Anesthesia was regulated with slower ventilation frequency, without causing hypoxia. The skin and incision edges were protected, the field was radiated (with 6 MeV electron beam of 10 Gy) and the incision was closed. In our cases, there were no major postoperative surgical or early radiotherapy related complications. Conclusion: The completion of another stage of local therapy with IObRT during surgery positively effects sequencing of other treatments like chemotherapy, hormonotherapy and radiotherapy, if required. IObRT increases disease free and overall survival, as well as quality of life in breast cancer patients. PMID:26985156

  3. Big Data Analytics for Prostate Radiotherapy

    PubMed Central

    Coates, James; Souhami, Luis; El Naqa, Issam

    2016-01-01

    Radiation therapy is a first-line treatment option for localized prostate cancer and radiation-induced normal tissue damage are often the main limiting factor for modern radiotherapy regimens. Conversely, under-dosing of target volumes in an attempt to spare adjacent healthy tissues limits the likelihood of achieving local, long-term control. Thus, the ability to generate personalized data-driven risk profiles for radiotherapy outcomes would provide valuable prognostic information to help guide both clinicians and patients alike. Big data applied to radiation oncology promises to deliver better understanding of outcomes by harvesting and integrating heterogeneous data types, including patient-specific clinical parameters, treatment-related dose–volume metrics, and biological risk factors. When taken together, such variables make up the basis for a multi-dimensional space (the “RadoncSpace”) in which the presented modeling techniques search in order to identify significant predictors. Herein, we review outcome modeling and big data-mining techniques for both tumor control and radiotherapy-induced normal tissue effects. We apply many of the presented modeling approaches onto a cohort of hypofractionated prostate cancer patients taking into account different data types and a large heterogeneous mix of physical and biological parameters. Cross-validation techniques are also reviewed for the refinement of the proposed framework architecture and checking individual model performance. We conclude by considering advanced modeling techniques that borrow concepts from big data analytics, such as machine learning and artificial intelligence, before discussing the potential future impact of systems radiobiology approaches. PMID:27379211

  4. Surgery Followed by Radiotherapy Versus Radiotherapy Alone for Metastatic Spinal Cord Compression From Unfavorable Tumors

    SciTech Connect

    Rades, Dirk; Huttenlocher, Stefan; Bajrovic, Amira; Karstens, Johann H.; Adamietz, Irenaeus A.; Kazic, Nadja; Rudat, Volker; Schild, Steven E.

    2011-12-01

    Purpose: Despite a previously published randomized trial, controversy exists regarding the benefit of adding surgery to radiotherapy for metastatic spinal cord compression (MSCC). It is thought that patients with MSCC from relatively radioresistant tumors or tumors associated with poor functional outcome after radiotherapy alone may benefit from surgery. This study focuses on these tumors. Methods and Materials: Data from 67 patients receiving surgery plus radiotherapy (S+RT) were matched to 134 patients (1:2) receiving radiotherapy alone (RT). Groups were matched for 10 factors and compared for motor function, ambulatory status, local control, and survival. Additional separate matched-pair analyses were performed for patients receiving direct decompressive surgery plus stabilization of involved vertebrae (DDSS) and patients receiving laminectomy (LE). Results: Improvement of motor function occurred in 22% of patients after S+RT and 16% after RT (p = 0.25). Posttreatment ambulatory rates were 67% and 61%, respectively (p = 0.68). Of nonambulatory patients, 29% and 19% (p = 0.53) regained ambulatory status. One-year local control rates were 85% and 89% (p = 0.87). One-year survival rates were 38% and 24% (p = 0.20). The matched-pair analysis of patients receiving LE showed no significant differences between both therapies. In the matched-pair analysis of patients receiving DDSS, improvement of motor function occurred more often after DDSS+RT than RT (28% vs. 19%, p = 0.024). Posttreatment ambulatory rates were 86% and 67% (p = 0.30); 45% and 18% of patients regained ambulatory status (p = 0.29). Conclusions: Patients with MSCC from an unfavorable primary tumor appeared to benefit from DDSS but not LE when added to radiotherapy in terms of improved functional outcome.

  5. [Quality and safety management for radiotherapy].

    PubMed

    Pourel, N; Meyrieux, C; Perrin, B

    2016-09-01

    Quality and safety management have been implemented for many years in healthcare structures (hospitals treating cancer, private radiotherapy centres). Their structure and formalization have improved progressively over time. These recommendations aim at describing the link between quality and safety management through its organization scheme based on quality-safety policy, process approach, document management and quality measurement. Dedicated tools, such as experience feedback, a priori risk mapping, to-do-lists and check-lists are shown as examples and recommended as routine practice. Copyright © 2016 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  6. Breast Molecular Profiling and Radiotherapy Considerations.

    PubMed

    Mahmoud, Omar; Haffty, Bruce G

    2016-01-01

    The last decade has seen major changes in the management of breast cancer. Heterogeneity regarding histology, therapeutic response, dissemination patterns, and patient outcome is evident. Molecular profiling provides an accurate tool to predict treatment outcome compared with classical clinicopathologic features. The genomic profiling unveiled the heterogeneity of breast cancer and identified distinct biologic subtypes. These advanced techniques were integrated into the clinical management; predicting systemic therapy benefit and overall survival. Utilizing genotyping to guide locoregional management decisions needs further characterization. In this chapter we will review available data on molecular classification of breast cancer, their association with locoregional outcome, their radiobiological properties and radiotherapy considerations.

  7. State of the art of radiotherapy.

    PubMed

    Garrido, Pilar; Olmedo, Eugenia

    2013-06-01

    Locally advanced or stage III disease accounts for ~30% of patients with non-small-cell lung cancer (NSCLC), which means only in the United States, more than 50,000 new patients each year. Stage III is a very heterogeneous disease, the management of patients is complex and several conditions (performance status, weight loss, comorbidities, characteristics of nodal involvement or resectability) must be considered before selecting the best treatment, which in most cases is chemotherapy (CT) and radiotherapy (RT). In this article, we will review key changes in the management of unresectable stage III during the last decades. Also we will highlight some challenges and areas of active research.

  8. Intestinal lymphangiectasia secondary to radiotherapy and chemotherapy

    SciTech Connect

    Rao, S.S.; Dundas, S.; Holdsworth, C.D.

    1987-08-01

    We report a case of intestinal lymphangiectasia secondary to radiotherapy and chemotherapy. The patient also had small bowel bacterial overgrowth and pancreatic insufficiency. Lymphatic ectasia as a histological feature has been described previously in association with postradiotherapy malabsorption, but radiation-induced lymphangiectasia producing clinical manifestations has hitherto not been reported. Replacement of dietary long-chain fats with medium-chain triglycerides, pancreatic enzyme supplements, and a short course of oxytetracycline, resulted in dramatic clinical improvement. The possibility of intestinal lymphangiectasia should be borne in mind in patients with postradiotherapy malabsorption. A low serum albumin and lymphocyte count should draw attention to this possibility.

  9. Basic immunology of antibody targeted radiotherapy

    SciTech Connect

    Wong, Jeffrey Y.C. . E-mail: jwong@coh.org

    2006-10-01

    Antibody targeted radiotherapy brings an important new treatment modality to Radiation oncology clinic. Radiation dose to tumor and normal tissues are determined by a complex interplay of antibody, antigen, tumor, radionuclide, and host-related factors. A basic understanding of these immunologic and physiologic factors is important to optimally utilize this therapy in the clinic. Preclinical and clinical studies need to be continued to broaden our understanding and to develop new strategies to further improve the efficacy of this promising form of targeted therapy.

  10. Characteristics of in vivo radiotherapy dosimetry.

    PubMed

    Edwards, C R; Mountford, P J

    2009-11-01

    The recent discussion and debate about the use of in vivo dosimetry as a routine component of the radiotherapy treatment process has not included the limitations introduced by the physical characteristics of the detectors. Although a robust calibration procedure will ensure acceptable uncertainties in the measurements of tumour dose, further work is required to confirm the accuracy of critical organ measurements with a diode or a thermoluminescent dosemeter outside the main field owing to limitations caused by a non-uniform X-ray energy response of the detector, differences between the X-ray energy spectrum inside and outside the main field, and contaminating electrons.

  11. Oral mucositis. A complication of radiotherapy

    SciTech Connect

    Rider, C.A. )

    1990-11-01

    Oral mucositis is a complication of head and neck radiotherapy. It is understood what causes the inflammation and what biological tissue changes occur, however, a definite cure for oral mucositis has not yet been found. Supportive treatments, analgesics, antimicrobials and anti-inflammatory agents have been prescribed, none of which has been a thorough measure of treatment. An effective cure for oral mucositis is still in the midst of scientific research. In the interim local palliative treatments will help to alleviate the patients', debilitating symptoms.

  12. Ichthyosiform scaling secondary to megavoltage radiotherapy

    SciTech Connect

    Ross, E.V. )

    1991-07-01

    Acquired ichthyosis is a rare dermatosis associated with a number of malignancies. Side effects seen on the skin secondary to megavoltage radiotherapy are uncommon but may include fine dry desquamation and tanning. The authors present a case of ichthyosiform scaling limited to the radiation fields in a patient treated for brain metastases of a primary small cell lung carcinoma. The reader is reminded that side effects of megavoltage treatment do occur on the skin. A brief review of these effects is included. 5 references.

  13. Radiotherapy changes of the pediatric hip

    SciTech Connect

    Libshitz, H.I.; Edeiken, B.S.

    1981-09-01

    Significant radiation-induced abnormalities (aseptic necrosis of the femoral heads, slipped capital femoral epiphysis, radiation-induced sarcoma) were identified in eight of 44 patients aged 16 years or younger at the time of radiotherapy and followed for at least 3 years. The incidence is 18% in the entire group and 25% (8/32) if only patients with radiographs of the hips 3 or more years after therapy are considered. The first evidence of abnormality developed 13 years after irradiation in one patient. The need for long term follow-up of therapeutically irradiated children is stressed.

  14. Particle radiotherapy with carbon ion beams

    PubMed Central

    2013-01-01

    Carbon ion radiotherapy offers superior dose conformity in the treatment of deep-seated malignant tumours compared with conventional X-ray therapy. In addition, carbon ion beams have a higher relative biological effectiveness compared with protons or X-ray beams. The algorithm of treatment planning and beam delivery system is tailored to the individual parameters of the patient. The present article reviews the available literatures for various disease sites including the head and neck, skull base, lung, liver, prostate, bone and soft tissues and pelvic recurrence of rectal cancer as well as physical and biological properties. PMID:23497542

  15. SU-E-T-604: Penumbra Characteristics of a New InCiseâ„¢ Multileaf Collimator of CyberKnife M6â„¢ System

    SciTech Connect

    Hwang, M; Jang, S; Ozhasoglu, C; Lalonde, R; Heron, D; Huq, M

    2015-06-15

    Purpose: The InCise™ Multileaf Collimator (MLC) of CyberKnife M6™ System has been released recently. The purpose of this study was to explore the dosimetric characteristics of the new MLC. In particular, the penumbra characteristics of MLC fields at varying locations are evaluated. Methods: EBT3-based film measurements were performed with varying MLC fields ranging from 7.5 mm to 27.5 mm. Seventeen regions of interests (ROIs) were identified for irradiation. These are regions located at the central area (denoted as reference field), at the left/right edge areas of reference open field, at an intermediate location between central and edge area. Single beam treatment plans were designed by using the MultiPlan and was delivered using the Blue Phantom. Gafchromic films were irradiated at 1.5 cm depth in the Blue Phantom and analyzed using the Film Pro software. Variation of maximum dose, penumbra of MLC-defined fields, and symmetry/flatness were calculated as a function of locations of MLC fields. Results: The InCise™ MLC System showed relatively consistent dose distribution and penumbra size with varying locations of MLC fields. The measured maximum dose varied within 5 % at different locations compared to that at the central location and agreed with the calculated data well within 2%. The measured penumbrae were in the range of 2.9 mm and 3.7 mm and were relatively consistent regardless of locations. However, dose profiles in the out-of-field and in-field regions varied with locations and field sizes. Strong variation was seen for all fields located at 55 mm away from the central field. The MLC leakage map showed that the leakage is dependent on position. Conclusion: The size of penumbra and normalized maximum dose for MLC-defined fields were consistent in different regions of MLC. However, dose profiles in the out-field region varied with locations and field sizes.

  16. SU-F-SPS-02: Accuracy of the Small Field Dosimetry Using the Monte Carlo and Sequential Dose Calculation Algorithms of Multiplan Treatment Planning System Within and Beyond Heterogeneous Media for Cyberknife M6 Unit

    SciTech Connect

    Serin, E.; Codel, G.; Mabhouti, H.; Cebe, M.; Sanli, E.; Pacaci, P.; Kucuk, N.; Kucukmorkoc, E.; Doyuran, M.; Canoglu, D.; Altinok, A.; Acar, H.; Caglar Ozkok, H.

    2016-06-15

    Purpose: In small field geometries, the electronic equilibrium can be lost, making it challenging for the dose-calculation algorithm to accurately predict the dose, especially in the presence of tissue heterogeneities. In this study, dosimetric accuracy of Monte Carlo (MC) advanced dose calculation and sequential algorithms of Multiplan treatment planning system were investigated for small radiation fields incident on homogeneous and heterogeneous geometries. Methods: Small open fields of fixed cones of Cyberknife M6 unit 100 to 500 mm2 were used for this study. The fields were incident on in house phantom containing lung, air, and bone inhomogeneities and also homogeneous phantom. Using the same film batch, the net OD to dose calibration curve was obtained using CK with the 60 mm fixed cone by delivering 0- 800 cGy. Films were scanned 48 hours after irradiation using an Epson 1000XL flatbed scanner. The dosimetric accuracy of MC and sequential algorithms in the presence of the inhomogeneities was compared against EBT3 film dosimetry Results: Open field tests in a homogeneous phantom showed good agreement between two algorithms and film measurement For MC algorithm, the minimum gamma analysis passing rates between measured and calculated dose distributions were 99.7% and 98.3% for homogeneous and inhomogeneous fields in the case of lung and bone respectively. For sequential algorithm, the minimum gamma analysis passing rates were 98.9% and 92.5% for for homogeneous and inhomogeneous fields respectively for used all cone sizes. In the case of the air heterogeneity, the differences were larger for both calculation algorithms. Overall, when compared to measurement, the MC had better agreement than sequential algorithm. Conclusion: The Monte Carlo calculation algorithm in the Multiplan treatment planning system is an improvement over the existing sequential algorithm. Dose discrepancies were observed for in the presence of air inhomogeneities.

  17. Monte Carlo simulated correction factors for output factor measurement with the CyberKnife system—results for new detectors and correction factor dependence on measurement distance and detector orientation

    NASA Astrophysics Data System (ADS)

    Francescon, P.; Kilby, W.; Satariano, N.

    2014-03-01

    A previous study of the corrections needed for output factor measurements with the CyberKnife system has been extended to include new diode detectors (IBA SFD and Exradin D1V), an air filled microchamber (Exradin CC01) and a scintillation detector (Exradin W1). The dependence of the corrections on detector orientation (detector long axis parallel versus perpendicular to the beam axis) and source to detector distance (SDD) was evaluated for these new detectors and for those in our previous study. The new diodes are found to over-respond at the smallest (5 mm) field size by 2.5% (D1V) and 3.3% (SFD) at 800 mm SDD, while the CC01 under-responds by 7.4% at the same distance when oriented parallel to the beam. Corrections for all detectors tend to unity as field size increases. The W1 corrections are <0.5% at all field sizes. Microchamber correction factors increase substantially if the detector is oriented perpendicular to the beam (by up to 23% for the PTW 31014). Corrections also vary with SDD, with the largest variations seen for microchambers in the perpendicular orientation (up to 13% change at 650 mm SDD versus 800 mm) and smallest for diodes (˜1% change at 650 mm versus 800 mm). The smallest and most stable corrections are found for diodes, liquid filled microchambers and scintillation detectors, therefore these should be preferred for small field output factor measurements. If air filled microchambers are used, then the parallel orientation should be preferred to the perpendicular, and care should be taken to use corrections appropriate to the measurement SDD.

  18. Image-Guided Radiotherapy and -Brachytherapy for Cervical Cancer

    PubMed Central

    Dutta, Suresh; Nguyen, Nam Phong; Vock, Jacqueline; Kerr, Christine; Godinez, Juan; Bose, Satya; Jang, Siyoung; Chi, Alexander; Almeida, Fabio; Woods, William; Desai, Anand; David, Rick; Karlsson, Ulf Lennart; Altdorfer, Gabor

    2015-01-01

    Conventional radiotherapy for cervical cancer relies on clinical examination, 3-dimensional conformal radiotherapy (3D-CRT), and 2-dimensional intracavitary brachytherapy. Excellent local control and survival have been obtained for small early stage cervical cancer with definitive radiotherapy. For bulky and locally advanced disease, the addition of chemotherapy has improved the prognosis but toxicity remains significant. New imaging technology such as positron-emission tomography and magnetic resonance imaging has improved tumor delineation for radiotherapy planning. Image-guided radiotherapy (IGRT) may decrease treatment toxicity of whole pelvic radiation because of its potential for bone marrow, bowel, and bladder sparring. Tumor shrinkage during whole pelvic IGRT may optimize image-guided brachytherapy (IGBT), allowing for better local control and reduced toxicity for patients with cervical cancer. IGRT and IGBT should be integrated in future prospective studies for cervical cancer. PMID:25853092

  19. Image-guided radiotherapy and -brachytherapy for cervical cancer.

    PubMed

    Dutta, Suresh; Nguyen, Nam Phong; Vock, Jacqueline; Kerr, Christine; Godinez, Juan; Bose, Satya; Jang, Siyoung; Chi, Alexander; Almeida, Fabio; Woods, William; Desai, Anand; David, Rick; Karlsson, Ulf Lennart; Altdorfer, Gabor

    2015-01-01

    Conventional radiotherapy for cervical cancer relies on clinical examination, 3-dimensional conformal radiotherapy (3D-CRT), and 2-dimensional intracavitary brachytherapy. Excellent local control and survival have been obtained for small early stage cervical cancer with definitive radiotherapy. For bulky and locally advanced disease, the addition of chemotherapy has improved the prognosis but toxicity remains significant. New imaging technology such as positron-emission tomography and magnetic resonance imaging has improved tumor delineation for radiotherapy planning. Image-guided radiotherapy (IGRT) may decrease treatment toxicity of whole pelvic radiation because of its potential for bone marrow, bowel, and bladder sparring. Tumor shrinkage during whole pelvic IGRT may optimize image-guided brachytherapy (IGBT), allowing for better local control and reduced toxicity for patients with cervical cancer. IGRT and IGBT should be integrated in future prospective studies for cervical cancer.

  20. Contribution of FDOPA PET to radiotherapy planning for advanced glioma

    NASA Astrophysics Data System (ADS)

    Dowson, Nicholas; Fay, Michael; Thomas, Paul; Jeffree, Rosalind; McDowall, Robert; Winter, Craig; Coulthard, Alan; Smith, Jye; Gal, Yaniv; Bourgeat, Pierrick; Salvado, Olivier; Crozier, Stuart; Rose, Stephen

    2014-03-01

    Despite radical treatment with surgery, radiotherapy and chemotherapy, advanced gliomas recur within months. Geographic misses in radiotherapy planning may play a role in this seemingly ineluctable recurrence. Planning is typically performed on post-contrast MRIs, which are known to underreport tumour volume relative to FDOPA PET scans. FDOPA PET fused with contrast enhanced MRI has demonstrated greater sensitivity and specificity than MRI alone. One sign of potential misses would be differences between gross target volumes (GTVs) defined using MRI alone and when fused with PET. This work examined whether such a discrepancy may occur. Materials and Methods: For six patients, a 75 minute PET scan using 3,4-dihydroxy-6-18F-fluoro-L-phynel-alanine (18F-FDOPA) was taken within 2 days of gadolinium enhanced MRI scans. In addition to standard radiotherapy planning by an experienced radiotherapy oncologist, a second gross target volume (GTV) was defined by an experienced nuclear medicine specialist for fused PET and MRI, while blinded to the radiotherapy plans. The volumes from standard radiotherapy planning were compared to the PET defined GTV. Results: The comparison indicated radiotherapy planning would change in several cases if FDOPA PET data was available. PET-defined contours were external to 95% prescribed dose for several patients. However, due to the radiotherapy margins, the discrepancies were relatively small in size and all received a dose of 50 Gray or more. Conclusions: Given the limited size of the discrepancies it is uncertain that geographic misses played a major role in patient outcome. Even so, the existence of discrepancies indicates that FDOPA PET could assist in better defining margins when planning radiotherapy for advanced glioma, which could be important for highly conformal radiotherapy plans.

  1. Cardiac Side-effects From Breast Cancer Radiotherapy.

    PubMed

    Taylor, C W; Kirby, A M

    2015-11-01

    Breast cancer radiotherapy reduces the risk of cancer recurrence and death. However, it usually involves some radiation exposure of the heart and analyses of randomised trials have shown that it can increase the risk of heart disease. Estimates of the absolute risks of radiation-related heart disease are needed to help oncologists plan each individual woman's treatment. The risk for an individual woman varies according to her estimated cardiac radiation dose and her background risk of ischaemic heart disease in the absence of radiotherapy. When it is known, this risk can then be compared with the absolute benefit of the radiotherapy. At present, many UK cancer centres are already giving radiotherapy with mean heart doses of less than 3 Gy and for most women the benefits of the radiotherapy will probably far outweigh the risks. Technical approaches to minimising heart dose in breast cancer radiotherapy include optimisation of beam angles, use of multileaf collimator shielding, intensity-modulated radiotherapy, treatment in a prone position, treatment in deep inspiration (including the use of breath-hold and gating techniques), proton therapy and partial breast irradiation. The multileaf collimator is suitable for many women with upper pole left breast cancers, but for women with central or lower pole cancers, breath-holding techniques are now recommended in national UK guidelines. Ongoing work aims to identify ways of irradiating pan-regional lymph nodes that are effective, involve minimal exposure of organs at risk and are feasible to plan, deliver and verify. These will probably include wide tangent-based field-in-field intensity-modulated radiotherapy or arc radiotherapy techniques in combination with deep inspiratory breath-hold, and proton beam irradiation for women who have a high predicted heart dose from intensity-modulated radiotherapy.

  2. Cataractogenesis after Cobalt-60 eye plaque radiotherapy

    SciTech Connect

    Kleineidam, M.; Augsburger, J.J. ); Hernandez, C.; Glennon, P.; Brady, L.W. )

    1993-07-15

    This study was designed to estimate the actuarial incidence of typical postirradiation cataracts and to identify prognostic factors related to their development in melanoma-containing eyes treated by Cobalt-60 plaque radiotherapy. A special interest was the impact of calculated radiation dose and dose-rate to the lens. The authors evaluated the actuarial occurrence of post-irradiation cataract in 365 patients with primary posterior uveal melanoma treated by Cobalt-60 plaque radiotherapy between 1976 and 1986. Only 22% (S.E. = 4.6%) of the patients who received a total dose of 6 to 20 Gy at the center of the lens developed a visually significant cataract attributable to the radiation within 5 years after treatment. Using multivariate Cox proportional hazards modeling, the authors identified thickness of the tumor, location of the tumor's anterior margin relative to the equatorward and the ora serrata, and diameter of the eye plaque used as the best combination of covariables for predicting length of time until development of cataract. Surprisingly, the dose of radiation delivered to the lens, which was strongly correlated to all of these covariables, was not a significant predictive factor in multivariate analysis. The results suggest that success of efforts to decrease the occurrence rate of post-irradiation cataracts by better treatment planning might be limited in patients with posterior uveal melanoma. 21 refs., 2 figs., 5 tabs.

  3. In vivo dosimetry in external beam radiotherapy.

    PubMed

    Mijnheer, Ben; Beddar, Sam; Izewska, Joanna; Reft, Chester

    2013-07-01

    In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large-scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation-induced radionuclides. In the final analysis, we will show in this Vision 20∕20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors' opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks.

  4. Dose masking feature for BNCT radiotherapy planning

    DOEpatents

    Cook, Jeremy L.; Wessol, Daniel E.; Wheeler, Floyd J.

    2000-01-01

    A system for displaying an accurate model of isodoses to be used in radiotherapy so that appropriate planning can be performed prior to actual treatment on a patient. The nature of the simulation of the radiotherapy planning for BNCT and Fast Neutron Therapy, etc., requires that the doses be computed in the entire volume. The "entire volume" includes the patient and beam geometries as well as the air spaces in between. Isodoses derived from the computed doses will therefore extend into the air regions between the patient and beam geometries and thus depict the unrealistic possibility that radiation deposition occurs in regions containing no physical media. This problem is solved by computing the doses for the entire geometry and then masking the physical and air regions along with the isodose contours superimposed over the patient image at the corresponding plane. The user is thus able to mask out (remove) the contour lines from the unwanted areas of the image by selecting the appropriate contour masking region from the raster image.

  5. [Antalgic radiotherapy in lumbosacral carcinomatous neuropathies].

    PubMed

    Russi, E G; Gaeta, M; Pergolizzi, S; Settineri, N; Frosina, P; De Renzis, C

    1994-06-01

    Lumbosacral carcinomatous neuropathy (LCN) may be caused by infiltration or compression of the lumbosacral plexi and nerves from intrapelvic or paraaortic neoplasms. The authors submitted 23 patients complaining of LCN with CT documented intrapelvic or paraaortic tumors to palliative radiotherapy. Megavoltage external beam irradiation was administered using a 6-MV linear accelerator. Treatment field sizes ranged from 56 cm2 to 235 cm2 (mean: 150.54 cm2) and encompassed only the site where the disease involved the lumbosacral plexus or its branches. > or = 3 Gy/day fractions were used. Twenty-one of 22 assessable patients (95.4%) obtained LCN pain relief; 19 (86.3%) obtained complete LCN pain relief. The median time to pain progression (TPP) was 150 days (range: 39-510 days). The median survival was 165 days. Seven patients were LCN pain-free at death. Two patients are alive and LCN pain-free. The remaining 12 patients had recurrent LCN pain: four of them were reirradiated at the site of previous neuropathy and only two had partial relief again. The authors conclude that it is advisable to submit to palliative radiotherapy the inoperable disseminated and/or recurrent cancer patients complaining of LCN, to use large fractions not to occupy the extant time of their already short life-expectancy, and to design small fields to avoid acute side-effects.

  6. 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.

  7. In vivo dosimetry in external beam radiotherapy

    SciTech Connect

    Mijnheer, Ben; Beddar, Sam; Izewska, Joanna; Reft, Chester

    2013-07-15

    In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large-scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation-induced radionuclides. In the final analysis, we will show in this Vision 20/20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors' opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks.

  8. Cerebral aneurysms following radiotherapy for medulloblastoma

    SciTech Connect

    Benson, P.J.; Sung, J.H.

    1989-04-01

    Three patients, two males and one female aged 21, 14, and 31 years, respectively, developed cerebral saccular aneurysms several years after undergoing radiotherapy for cerebellar medulloblastoma at 2, 5, and 14 years of age, respectively. Following surgery, all three received combined cobalt-60 irradiation and intrathecal colloidal radioactive gold (/sup 198/Au) therapy, and died from rupture of the aneurysm 19, 9, and 17 years after the radiotherapy, respectively. Autopsy examination revealed no recurrence of the medulloblastoma, but widespread radiation-induced vasculopathy was found at the base of the brain and in the spinal cord, and saccular aneurysms arose from the posterior cerebral arteries at the basal cistern or choroidal fissure. The aneurysms differed from the ordinary saccular aneurysms of congenital type in their location and histological features. Their locations corresponded to the areas where intrathecally administered colloidal /sup 198/Au is likely to pool, and they originated directly from a segment of the artery rather than from a branching site as in congenital saccular aneurysms. It is, therefore, concluded that the aneurysms in these three patients were most likely radiation-induced.

  9. Radiotherapy dosimetry using a commercial OSL system

    SciTech Connect

    Viamonte, A.; Rosa, L. A. R. da; Buckley, L. A.; Cherpak, A.; Cygler, J. E.

    2008-04-15

    A commercial optically stimulated luminescence (OSL) system developed for radiation protection dosimetry by Landauer, Inc., the InLight microStar reader, was tested for dosimetry procedures in radiotherapy. The system uses carbon-doped aluminum oxide, Al{sub 2}O{sub 3}:C, as a radiation detector material. Using this OSL system, a percent depth dose curve for {sup 60}Co gamma radiation was measured in solid water. Field size and SSD dependences of the detector response were also evaluated. The dose response relationship was investigated between 25 and 400 cGy. The decay of the response with time following irradiation and the energy dependence of the Al{sub 2}O{sub 3}:C OSL detectors were also measured. The results obtained using OSL dosimeters show good agreement with ionization chamber and diode measurements carried out under the same conditions. Reproducibility studies show that the response of the OSL system to repeated exposures is 2.5% (1sd), indicating a real possibility of applying the Landauer OSL commercial system for radiotherapy dosimetric procedures.

  10. Liver-Directed Radiotherapy for Hepatocellular Carcinoma

    PubMed Central

    Keane, Florence K.; Wo, Jennifer Y.; Zhu, Andrew X.; Hong, Theodore S.

    2016-01-01

    Background The incidence of hepatocellular carcinoma (HCC) continues to increase world-wide. Many patients present with advanced disease with extensive local tumor or vascular invasion and are not candidates for traditionally curative therapies such as orthotopic liver transplantation (OLT) or resection. Radiotherapy (RT) was historically limited by its inability to deliver a tumoricidal dose; however, modern RT techniques have prompted renewed interest in the use of liver-directed RT to treat patients with primary hepatic malignancies. Summary The aim of this review was to discuss the use of external beam RT in the treatment of HCC, with particular focus on the use of stereotactic body radiotherapy (SBRT). We review the intricacies of SBRT treatment planning and delivery. Liver-directed RT involves accurate target identification, precise and reproducible patient immobilization, and assessment of target and organ motion. We also summarize the published data on liver-directed RT, and demonstrate that it is associated with excellent local control and survival rates, particularly in patients who are not candidates for OLT or resection. Key Messages Modern liver-directed RT is safe and effective for the treatment of HCC, particularly in patients who are not candidates for OLT or resection. Liver-directed RT, including SBRT, depends on accurate target identification, precise and reproducible patient immobilization, and assessment of target and organ motion. Further prospective studies are needed to fully delineate the role of liver-directed RT in the treatment of HCC. PMID:27493895

  11. [Exclusive radiotherapy in stage III esophageal cancer].

    PubMed

    Tombolini, V; Banelli, E; Cavaceppi, P; Donato, V; Montagna, A; Raffetto, N; Santarelli, M; Vitturini, A

    2000-01-01

    The purpose of the report is to evaluate the role of radiotherapy in the treatment of stage III esophageal carcinoma and to analyze the influence of site, extension, grade of dysphagia and histology on local control and survival. Twenty males and 6 females were submitted to external beam therapy with 4-6 MV X-rays and received 60-70 Gy in fractions of 180 cGY to 200 cGy per day, 5 days a week. Radiation therapy technique was two posterior oblique portals and a single anterior field at 100 cm SAD. After 4500 cGy portals were coned down, holding the spinal cord dose below 4500 cGy. Global response to therapy was 73.1%. Median survival was 11 months. The 2-year survival rate was 12.5% in patients with lesions smaller than 5 cm and 5.5% for those with lesions greater than 5 cm. Patients with grade 2 dysphagia had a median survival of 16 months, those with grade 1, 11 months and 2 patients with grade 0, 4 and 9 months. In all patients mild to moderate esophagitis was observed. Two patients developed esophagotracheal fistula. Exclusively radiotherapy cannot be considered the treatment of choice in III stage patients. Primary chemoradiotherapy may emerge as the treatment of choice for cancer of the esophagus.

  12. Uses of megavoltage digital tomosynthesis in radiotherapy

    NASA Astrophysics Data System (ADS)

    Sarkar, Vikren

    With the advent of intensity modulated radiotherapy, radiation treatment plans are becoming more conformal to the tumor with the decreasing margins. It is therefore of prime importance that the patient be positioned correctly prior to treatment. Therefore, image guided treatment is necessary for intensity modulated radiotherapy plans to be implemented successfully. Current advanced imaging devices require costly hardware and software upgrade, and radiation imaging solutions, such as cone beam computed tomography, may introduce extra radiation dose to the patient in order to acquire better quality images. Thus, there is a need to extend current existing imaging device ability and functions while reducing cost and radiation dose. Existing electronic portal imaging devices can be used to generate computed tomography-like tomograms through projection images acquired over a small angle using the technique of cone-beam digital tomosynthesis. Since it uses a fraction of the images required for computed tomography reconstruction, use of this technique correspondingly delivers only a fraction of the imaging dose to the patient. Furthermore, cone-beam digital tomosynthesis can be offered as a software-only solution as long as a portal imaging device is available. In this study, the feasibility of performing digital tomosynthesis using individually-acquired megavoltage images from a charge coupled device-based electronic portal imaging device was investigated. Three digital tomosynthesis reconstruction algorithms, the shift-and-add, filtered back-projection, and simultaneous algebraic reconstruction technique, were compared considering the final image quality and radiation dose during imaging. A software platform, DART, was created using a combination of the Matlab and C++ languages. The platform allows for the registration of a reference Cone Beam Digital Tomosynthesis (CBDT) image against a daily acquired set to determine how to shift the patient prior to treatment. Finally

  13. Monte Carlo dose calculations in advanced radiotherapy

    NASA Astrophysics Data System (ADS)

    Bush, Karl Kenneth

    The remarkable accuracy of Monte Carlo (MC) dose calculation algorithms has led to the widely accepted view that these methods should and will play a central role in the radiotherapy treatment verification and planning of the future. The advantages of using MC clinically are particularly evident for radiation fields passing through inhomogeneities, such as lung and air cavities, and for small fields, including those used in today's advanced intensity modulated radiotherapy techniques. Many investigators have reported significant dosimetric differences between MC and conventional dose calculations in such complex situations, and have demonstrated experimentally the unmatched ability of MC calculations in modeling charged particle disequilibrium. The advantages of using MC dose calculations do come at a cost. The nature of MC dose calculations require a highly detailed, in-depth representation of the physical system (accelerator head geometry/composition, anatomical patient geometry/composition and particle interaction physics) to allow accurate modeling of external beam radiation therapy treatments. To perform such simulations is computationally demanding and has only recently become feasible within mainstream radiotherapy practices. In addition, the output of the accelerator head simulation can be highly sensitive to inaccuracies within a model that may not be known with sufficient detail. The goal of this dissertation is to both improve and advance the implementation of MC dose calculations in modern external beam radiotherapy. To begin, a novel method is proposed to fine-tune the output of an accelerator model to better represent the measured output. In this method an intensity distribution of the electron beam incident on the model is inferred by employing a simulated annealing algorithm. The method allows an investigation of arbitrary electron beam intensity distributions and is not restricted to the commonly assumed Gaussian intensity. In a second component of

  14. Bladder filling variation during conformal radiotherapy for rectal cancer

    NASA Astrophysics Data System (ADS)

    Sithamparam, S.; Ahmad, R.; Sabarudin, A.; Othman, Z.; Ismail, M.

    2017-05-01

    Conformal radiotherapy for rectal cancer is associated with small bowel toxicity mainly diarrhea. Treating patients with a full bladder is one of the practical solutions to reduce small bowel toxicity. Previous studies on prostate and cervix cancer patients revealed that maintaining consistent bladder volume throughout radiotherapy treatment is challenging. The aim of this study was to measure bladder volume variation throughout radiotherapy treatment. This study also measured the association between bladder volume changes and diarrhea. Twenty two rectal cancer patients were recruited prospectively. Patients were planned for treatment with full bladder following departmental bladder filling protocol and the planning bladder volume was measured during CT-simulation. During radiotherapy, the bladder volume was measured weekly using cone-beam computed tomography (CBCT) and compared to planning bladder volume. Incidence and severity of diarrhea were recorded during the weekly patient review. There was a negative time trend for bladder volume throughout five weeks treatment. The mean bladder volume decreased 18 % from 123 mL (SD 54 mL) during CT-simulation to 101 mL (SD 71 mL) on the 5th week of radiotherapy, but the decrease is not statistically significant. However, there was a large variation of bladder volume within each patient during treatment. This study showed an association between changes of bladder volume and diarrhea (P = 0.045). In conclusion bladder volume reduced throughout radiotherapy treatment for conformal radiotherapy for rectal cancer and there was a large variation of bladder volume within patients.

  15. Radiotherapy enhances laser palliation of malignant dysphagia: a randomised study.

    PubMed Central

    Sargeant, I R; Tobias, J S; Blackman, G; Thorpe, S; Glover, J R; Bown, S G

    1997-01-01

    BACKGROUND/AIMS: A major drawback of laser endoscopy in the palliation of malignant dysphagia is the need for repeated treatments. This study was designed to test whether external beam radiotherapy would reduce the necessity for repeated laser therapy. PATIENTS/METHODS: Sixty seven patients with inoperable oesophageal or gastric cardia cancers and satisfactory swallowing after initial laser recanalisation were randomised to palliative external beam radiotherapy (30 Gy in 10 fractions) or no radiotherapy. All patients underwent a 'check' endoscopy five weeks after initial recanalisation and were subsequently reendoscoped only for recurrent dysphagia, which occurred in 59 patients. RESULTS: Dysphagia was relieved equally well in both groups and the improvement was maintained with further endoscopic treatment. The initial dysphagia controlled interval and the duration between procedures required to maintain lifelong palliation (treatment interval) increased from five to nine weeks (median) in the radiotherapy group (p < 0.01 both parameters). Radiotherapy was well tolerated in all but three patients. One perforation occurred and two fistulae opened after dilatation in patients who received radiotherapy. CONCLUSION: Additional radiotherapy reduces the necessity for therapeutic endoscopy for a patient's remaining life. It has an important role in relatively well patients who are likely to survive long enough to benefit. PMID:9135526

  16. Laryngeal sensation and pharyngeal delay time after (chemo)radiotherapy.

    PubMed

    Maruo, Takashi; Fujimoto, Yasushi; Ozawa, Kikuko; Hiramatsu, Mariko; Suzuki, Atsushi; Nishio, Naoki; Nakashima, Tsutomu

    2014-08-01

    The objective of the study was to evaluate the association between changes in laryngeal sensation and initiation of swallowing reflex or swallowing function before and after (chemo)radiotherapy. A prospective study was conducted in a tertiary referral university hospital. Thirteen patients who received (chemo)radiotherapy for treatment of laryngeal or hypopharyngeal cancer were included. Laryngeal sensation was evaluated at the tip of the epiglottis before and 1, 3 months, and 1 year after (chemo)radiotherapy. Videofluoroscopy was performed at the same time. Quantitative determinations included changes in laryngeal sensation, computed analysis of pharyngeal delay time, the distance and velocity of hyoid bone movement during the phase of hyoid excursion, and pharyngeal residue rate (the proportion of the bolus that was left as residue in the pharynx at the first swallow). Laryngeal sensation significantly deteriorated 1 month after (chemo)radiotherapy, but there was a tendency to return to pretreatment levels 1 year after treatment. Neither pharyngeal delay time nor displacement of the hyoid bone changed significantly before and after (chemo)radiotherapy. In addition, there was no significant difference in the mean velocity of hyoid bone movement and the amount of stasis in the pharynx at the first swallow before and after (chemo)radiotherapy. After (chemo)radiotherapy, laryngeal sensation deteriorated. But, in this study, videofluoroscopy showed that swallowing reflex and function were maintained.

  17. Improving radiotherapy in cancer treatment: Promises and challenges

    PubMed Central

    Chen, Helen H.W.; Kuo, Macus Tien

    2017-01-01

    Effective radiotherapy for cancer has relied on the promise of maximally eradicating tumor cells while minimally killing normal cells. Technological advancement has provided state-of-the-art instrumentation that enables delivery of radiotherapy with great precision to tumor lesions with substantial reduced injury to normal tissues. Moreover, better understanding of radiobiology, particularly the mechanisms of radiation sensitivity and resistance in tumor lesions and toxicity in normal tissues, has improved the treatment efficacy of radiotherapy. Previous mechanism-based studies have identified many cellular targets that can affect radiation sensitivity, notably reactive oxygen species, DNA-damaging response signals, and tumor microenvironments. Several radiation sensitizers and protectors have been developed and clinically evaluated; however, many of these results are inconclusive, indicating that improvement remains needed. In this era of personalized medicine in which patients’ genetic variations, transcriptome and proteomics, tumor metabolism and microenvironment, and tumor immunity are available. These new developments have provided opportunity for new target discovery. Several radiotherapy sensitivity-associated “gene signatures” have been reported although clinical validations are needed. Recently, several immune modifiers have been shown to associate with improved radiotherapy in preclinical models and in early clinical trials. Combination of radiotherapy and immunocheckpoint blockade has shown promising results especially in targeting metastatic tumors through abscopal response. In this article, we succinctly review recent advancements in the areas of mechanism-driven targets and exploitation of new targets from current radio-oncogenomic and radiation-immunotherapeutic approaches that bear clinical implications for improving the treatment efficacy of radiotherapy.

  18. Challenge and Hope in Radiotherapy of Hepatocellular Carcinoma

    PubMed Central

    2009-01-01

    Hepatocellular carcinoma (HCC) is one of the most critical global health issues. With frequent association of viral liver disease, HCC is highly complex, harboring both cancer and chronic liver disease. The tumor stage and underlying liver function are both major determinants of the treatment selection as well as prognosis in HCC patients, thus allowing no more than a 20% chance for potentially curative therapies. Radiotherapy technology has been evolved remarkably during the past decade, and radiation can be precisely delivered, thereby permitting higher doses to the tumour and reduced doses to surrounding normal tissues. There has been increasing interest in the merits of radiotherapy in HCC over the past few years, as indicated by a Pub Med search. Radiotherapy has been used as the definitive therapy with curative intent in early stage tumours. It has been used also in combination with TACE for intermediate stage tumours. In locally advanced tumours, radiotherapy has been combined with systemic agents. Despite its efficacy, radiotherapy has not yet been incorporated into the standard management guidelines of HCC. The lack of high evidence level data, especially randomized controlled trials, has posed an obstacle in including radiotherapy into the routine treatment schema of HCC. Therefore, well-designed prospective studies are strongly recommended using developing technology for radiotherapy alone or combination therapies. Also, many issues such as the optimal dose-fractionation, intra- or extrahepatic metastasis after radiotherapy, and radiation-induced hepatic dysfunction remain to be solved. In this review, current status of radiotherapy for HCC will be discussed with regard to technical consideration and combination strategy. The limitation and future perspectives will also be discussed. PMID:19881961

  19. Cerebral necrosis after 25Gy radiotherapy in childhood followed 28 years later by 54Gy radiotherapy.

    PubMed

    Koot, Radboud W; Stalpers, Lukas J A; Aronica, Eleonora; Andries Bosch, D

    2007-09-01

    The development of brain necrosis is life-long risk of repeat radiation therapy, even after a long time interval and a moderate radiation dose. We report on a 34-year-old patient who had prophylactic cranial irradiation with 25Gy and adjuvant chemotherapy in childhood for leukaemia and in adulthood, 28 years later, therapeutic radiotherapy with 54Gy for an atypical (WHO grade II) meningioma. About 2 years later he developed a contrast-enhancing lesion on MRI-scan that was indicative of a tumor according to a thallium-201 ((201)Tl) SPECT scan. Histopathology of the operated contrast-enhancing lesion showed extensive radionecrosis. Radiation necrosis is a small but serious risk after repeat radiation therapy, even after a very long-term interval, the delivery of small fractions and an average cumulative total dose. Patients undergoing repeat radiotherapy therefore need to be followed life-long for potential late radiation toxicity.

  20. Long-Term Breast Cancer Patient Outcomes After Adjuvant Radiotherapy Using Intensity-Modulated Radiotherapy or Conventional Tangential Radiotherapy.

    PubMed

    Yang, Jen-Fu; Lee, Meei-Shyuan; Lin, Chun-Shu; Chao, Hsing-Lung; Chen, Chang-Ming; Lo, Cheng-Hsiang; Fan, Chao-Yueh; Tsao, Chih-Cheng; Huang, Wen-Yen

    2016-03-01

    The aim of the article is to analyze breast cancer patient clinical outcomes after long-term follow-up using intensity-modulated radiotherapy (IMRT) or conventional tangential radiotherapy (cRT). We retrospectively reviewed patients with stage 0-III breast cancer who received breast conserving therapy between April 2004 and December 2007. Of the 234 patients, 103 (44%) were treated with IMRT and 131 (56%) were treated with cRT. A total prescription dose of 45 to 50 Gy (1.8-2 Gy per fraction) was delivered to the whole breast. A 14 Gy boost dose was delivered in 7 fractions. The median follow-up was 8.2 years. Five of 131 (3.8%) cRT-treated patients and 2 of 103 (1.9%) IMRT-treated patients had loco-regional failure. The 8-year loco-regional failure-free survival rates were 96.7% and 97.6% (P = 0.393) in the cRT and IMRT groups, respectively, whereas the 8-year disease-free survival (DFS) rates were 91.2% and 93.1%, respectively (P = 0.243). Patients treated with IMRT developed ≥ grade 2 acute dermatitis less frequently than patients treated with cRT (40.8% vs 56.5%; P = 0.017). There were no differences in late toxicity. IMRT reduces ≥ grade 2 acute skin toxicity. Local control, DFS, and overall survival were equivalent with IMRT and cRT. IMRT can be considered a standard technique for breast cancer treatment.

  1. Comparison of "sandwich chemo-radiotherapy" and six cycles of chemotherapy followed by adjuvant radiotherapy in patients with stage IIIC endometrial cancer: a single center experience.

    PubMed

    Dogan, Nasuh Utku; Yavas, Guler; Yavas, Cagdas; Ata, Ozlem; Yılmaz, Setenay Arzu; Celik, Cetin

    2013-10-01

    To compare "sandwich chemo-radiotherapy" with six cycles of chemotherapy followed by adjuvant radiotherapy with respect to tolerability and acute toxicity. Twenty-five women with surgically staged IIIC endometrial cancer were included. Treatment consisted of either three cycles of paclitaxel (175 mg/m²) and carboplatin (AUC 6) on a q21-day schedule followed by irradiation (45-50.4 Gy) or six cycles of the same chemotherapy followed by radiotherapy. Acute toxicity related to either chemotherapy or radiotherapy was evaluated. Median age was 61.5 years (range 36-83 years). Eleven patients had sandwich chemo-radiotherapy, and the other 14 patients had 6 cycles of chemotherapy followed by radiotherapy. Three out of the five patients who could not complete all the cycles in the sandwich chemo-radiotherapy group had pelvic and para-aortic radiotherapy. Acute radiotherapy related grade 1-2 gastrointestinal system (GIS) and genitourinary system (GUS) toxicities were observed in 72.8 and 63.6 % of patients, respectively, for sandwich group. Undesired treatment breaks in the course of radiotherapy were observed in six patients for sandwich chemo-radiotherapy and in one patient receiving six cycles of chemotherapy followed by radiotherapy. All the patients who had undesired treatment breaks in the sandwich chemo-radiotherapy group had pelvic and para-aortic radiotherapy. Sandwich chemo-radiotherapy seems to be more toxic particularly for patients who had pelvic and para-aortic irradiation. Therefore, it might be more convenient to delay radiotherapy after six cycles of chemotherapy for patients with the indication of pelvic para-aortic radiotherapy.

  2. Excellent Local Control With Stereotactic Radiotherapy Boost After External Beam Radiotherapy in Patients With Nasopharyngeal Carcinoma

    SciTech Connect

    Hara, Wendy; Loo, Billy W.; Goffinet, Don R.; Chang, Steven D.; Adler, John R.; Pinto, Harlan A.; Fee, Willard E.; Kaplan, Michael J.; Fischbein, Nancy J.; Le, Quynh-Thu

    2008-06-01

    Purpose: To determine long-term outcomes in patients receiving stereotactic radiotherapy (SRT) as a boost after external beam radiotherapy (EBRT) for locally advanced nasopharyngeal carcinoma (NPC). Methods and Materials: Eight-two patients received an SRT boost after EBRT between September 1992 and July 2006. Nine patients had T1, 30 had T2, 12 had T3, and 31 had T4 tumors. Sixteen patients had Stage II, 19 had Stage III, and 47 had Stage IV disease. Patients received 66 Gy of EBRT followed by a single-fraction SRT boost of 7-15 Gy, delivered 2-6 weeks after EBRT. Seventy patients also received cisplatin-based chemotherapy delivered concurrently with and adjuvant to radiotherapy. Results: At a median follow-up of 40.7 months (range, 6.5-144.2 months) for living patients, there was only 1 local failure in a patient with a T4 tumor. At 5 years, the freedom from local relapse rate was 98%, freedom from nodal relapse 83%, freedom from distant metastasis 68%, freedom from any relapse 67%, and overall survival 69%. Late toxicity included radiation-related retinopathy in 3, carotid aneurysm in 1, and radiographic temporal lobe necrosis in 10 patients, of whom 2 patients were symptomatic with seizures. Of 10 patients with temporal lobe necrosis, 9 had T4 tumors. Conclusion: Stereotactic radiotherapy boost after EBRT provides excellent local control for patients with NPC. Improved target delineation and dose homogeneity of radiation delivery for both EBRT and SRT is important to avoid long-term complications. Better systemic therapies for distant control are needed.

  3. Virtual reality training for radiotherapy becomes a reality.

    PubMed

    Phillips, R; Ward, J W; Page, L; Grau, C; Bojen, A; Hall, J; Nielsen, K; Nordentoft, V; Beavis, A W

    2008-01-01

    A report in 2007 to the UK Government identified a crisis in England for training staff and students for the radiotherapy treatment of cancer. The Hull authors have developed an immersive life size virtual environment of a radiotherapy treatment room, known as VERT, to address this problem. VERT provides the trainee with models, simulation, enhanced visualization and training aids for treatment of virtual patients in a virtual treatment room. In 2007 immersive VERT systems for radiotherapy training were established for training purposes at the University Aarhus Hospital (Denmark) and the Birmingham City University (UK). This paper reports on early evaluations of VERT by these two institutions.

  4. Synergistic Effects of Gold Nanocages in Hyperthermia and Radiotherapy Treatment

    NASA Astrophysics Data System (ADS)

    Zhang, Ai-wei; Guo, Wei-hua; Qi, Ya-fei; Wang, Jian-zhen; Ma, Xiang-xing; Yu, De-xin

    2016-06-01

    Gold nanocages (GNCs) are a promising material that not only converts near infrared (NIR) light to heat for the ablation of tumors but also acts as a radiosensitizer. The combination of hyperthermia and radiotherapy has a synergistic effect that can lead to significant tumor cell necrosis. In the current study, we synthesized GNCs that offered the combined effects of hyperthermia and radiotherapy. This combination strategy resulted in increased tumor cell apoptosis and significant tumor tissue necrosis. We propose that GNCs can be used for clinical treatment and to potentially overcome resistance to radiotherapy by clearly increasing the antitumor effect.

  5. [Endocrine function following cranial radiotherapy of neoplasms in children].

    PubMed

    Couselo Sánchez, J M; Fernández Bujía, M L; Pombo Arias, M; Devesa Múgiga, J; Tojo Sierra, R; Peña Guitán, J

    1984-01-01

    The effect of radiotherapy upon the diencephalo-hypophyseal axis was studied in 14 children that had received cranial radio-therapy (2,400 to 6,000 R) to treat different intracranial tumors. Several hormones were evaluated between 2 months and 3 years after radiotherapy was performed. 35.7 per 100 of the patients were deficient in growth hormone, 37.5 per 100 showed an alteration of prolactin secretion, and 28 per 100 an abnormal response to thyroid-stimulating hormone.

  6. Brain necrosis after radiotherapy for primary intracerebral tumor.

    PubMed

    Hohwieler, M L; Lo, T C; Silverman, M L; Freidberg, S R

    1986-01-01

    Radiotherapy is a standard postoperative treatment for cerebral glioma. We have observed the onset of symptoms related to brain necrosis, as opposed to recurrent tumor, in surviving patients. This has been manifest as dementia with a computed tomographic pattern of low density in the frontal lobe uninvolved with tumor, but within the field of radiotherapy. Two patients presented with mass lesions also unrelated to recurrent tumor. We question the necessity of full brain irradiation and suggest that radiotherapy techniques be altered to target the tumor and not encompass the entire brain.

  7. Intensity-Modulated Radiotherapy for Sinonasal Cancer: Improved Outcome Compared to Conventional Radiotherapy

    SciTech Connect

    Dirix, Piet; Vanstraelen, Bianca; Jorissen, Mark; Vander Poorten, Vincent; Nuyts, Sandra

    2010-11-15

    Purpose: To evaluate clinical outcome and toxicity of postoperative intensity-modulated radiotherapy (IMRT) for malignancies of the nasal cavity and paranasal sinuses. Methods and Materials: Between 2003 and 2008, 40 patients with cancer of the paranasal sinuses (n = 34) or nasal cavity (n = 6) received postoperative IMRT to a dose of 60 Gy (n = 21) or 66 Gy (n = 19). Treatment outcome and toxicity were retrospectively compared with that of a previous patient group (n = 41) who were also postoperatively treated to the same doses but with three-dimensional conformal radiotherapy without intensity modulation, from 1992 to 2002. Results: Median follow-up was 30 months (range, 4-74 months). Two-year local control, overall survival, and disease-free survival were 76%, 89%, and 72%, respectively. Compared to the three-dimensional conformal radiotherapy treatment, IMRT resulted in significantly improved disease-free survival (60% vs. 72%; p = 0.02). No grade 3 or 4 toxicity was reported in the IMRT group, either acute or chronic. The use of IMRT significantly reduced the incidence of acute as well as late side effects, especially regarding skin toxicity, mucositis, xerostomia, and dry-eye syndrome. Conclusions: Postoperative IMRT for sinonasal cancer significantly improves disease-free survival and reduces acute as well as late toxicity. Consequently, IMRT should be considered the standard treatment modality for malignancies of the nasal cavity and paranasal sinuses.

  8. Intensity-modulated radiotherapy significantly reduces xerostomia compared with conventional radiotherapy

    SciTech Connect

    Braam, Petra M. . E-mail: P.M.Braam@umcutrecht.nl; Terhaard, Chris H.J. M.D.; Roesink, Judith M.; Raaijmakers, Cornelis P.J.

    2006-11-15

    Purpose: Xerostomia is a severe complication after radiotherapy for oropharyngeal cancer, as the salivary glands are in close proximity with the primary tumor. Intensity-modulated radiotherapy (IMRT) offers theoretical advantages for normal tissue sparing. A Phase II study was conducted to determine the value of IMRT for salivary output preservation compared with conventional radiotherapy (CRT). Methods and Materials: A total of 56 patients with oropharyngeal cancer were prospectively evaluated. Of these, 30 patients were treated with IMRT and 26 with CRT. Stimulated parotid salivary flow was measured before, 6 weeks, and 6 months after treatment. A complication was defined as a stimulated parotid flow rate <25% of the preradiotherapy flow rate. Results: The mean dose to the parotid glands was 48.1 Gy (SD 14 Gy) for CRT and 33.7 Gy (SD 10 Gy) for IMRT (p < 0.005). The mean parotid flow ratio 6 weeks and 6 months after treatment was respectively 41% and 64% for IMRT and respectively 11% and 18% for CRT. As a result, 6 weeks after treatment, the number of parotid flow complications was significantly lower after IMRT (55%) than after CRT (87%) (p = 0.002). The number of complications 6 months after treatment was 56% for IMRT and 81% for CRT (p = 0.04). Conclusions: IMRT significantly reduces the number of parotid flow complications for patients with oropharyngeal cancer.

  9. Adjuvant radiotherapy for endometrial cancer--a comparative review of radiotherapy technique with acute toxicity.

    PubMed

    Koh, Y V; Tang, J I; Choo, B A; Koh, M S; Lee, K M

    2014-01-01

    The addition of pelvic radiotherapy to brachytherapy (EBRT-BT) in early-stage endometrial cancer is controversial and may cause unnecessary toxicity. The incidence of acute toxicity of EBRT-BT will have an impact on clinical decision and patient compliance but is currently poorly understood. This study compares the acute toxicities of EBRT-BT versus BT alone. Seventy-nine patients with FIGO Stage IA-II endometrial cancer who underwent adjuvant radiotherapy, (EBRT-BT or BT alone) from 2001 to 2011 were included in the study. Medical records of these patients were reviewed retrospectively and toxicity graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Patients were followed up for at least three months post-treatment to assess resolution of toxicity. The mean age of the study group was 60.6 years. Median follow-up was four years. Forty patients received EBRT-BT. There was a 37% increase in Grade 1-3 diarrhea with the addition of pelvic radiotherapy (OR 18.67, p < 0.0005) and a 34% increase in lethargy (p < 0.0005). There was also an increased occurrence of genitourinary and skin toxicities. Two patients in the EBRT-BT group required hospitalisation for severe diarrhea and three patients were unable to complete the treatment. All acute toxicities had resolved by three months post treatment. EBRT-BT causes significantly more acute toxicities compared to BT alone. Patients should be informed of this during counselling.

  10. Incidence of radiation toxicity in cervical cancer and endometrial cancer patients treated with radiotherapy alone versus adjuvant radiotherapy

    PubMed Central

    Roszak, Andrzej; Wareńczak-Florczak, Żaneta; Bratos, Krystyna; Milecki, Piotr

    2012-01-01

    Aim The study was made to evaluate early and late toxicity in a diversified group of patients receiving definitive or adjuvant radiotherapy in terms of clinical diagnosis and treatment methods. Background Radiotherapy is a standard way of treatment in cervical and endometrial cancer patients, both as definitive and adjuvant therapy. But every radiation treatment may be involved with toxicity. Materials and methods A detailed analysis was performed of 263 patients with gynaecological cancer treated with definitive (90 patients with cervical cancer received radiochemotherapy or radiotherapy exclusively) and adjuvant radiotherapy (38 with cervical and 135 with endometrial cancer). Results Acute reactions were found in 51.3% and late reactions were found in 14.8% of patients. It was stated that early (p < 0.007) and late (p < 0.003) post radiation reaction appear more frequently in women treated with definitive than adjuvant radiotherapy. The analysis of the whole group revealed higher rate of toxicity, both early and late, in the gastrointestinal tract than in the urinary system (p < 0.004). Comparing the subgroups, it was found that intestinal reactions occurred more frequently in the definitive radiotherapy group than in the adjuvant one. The occurrence of side effects was associated with the prolongation of total irradiation time due to necessary interruptions of radiotherapy. The comparison of the subgroups showed that interruptions occurred more frequently in patients receiving definitive rather than adjuvant radiotherapy (17.7–2.9%). Conclusions Definitive radiotherapy compared with adjuvant treatment may by associated with higher percentage of side effects caused by dose of therapy and correlation with chemotherapy. PMID:24377035

  11. The future of heavy ion radiotherapy

    SciTech Connect

    Jäkel, Oliver; Karger, Christian P.; Debus, Jürgen

    2008-12-15

    Currently, there is an increasing interest in heavy ion radiotherapy (RT) and a number of new facilities are being installed in Europe and Japan. This development is accompanied by intensive technical, physical, and clinical research. The authors identify six research fields where progress is likely and propose a thesis on the expected achievements for each of the fields: (1) Synchrotrons with active energy variation and three-dimensional beam scanning will be the standard in ion beam RT. (2) Common standards for precise measurement, prescription, and reporting of dose will be available. (3) Intensity-modulated particle therapy will be state-of-the-art. (4) Time-adaptive treatments of moving targets will be feasible. (5) Therapeutic effectiveness of heavy ions will be known for the most important indications while cost effectiveness will remain to be shown. (6) The potential of high-linear energy transfer radiation will be known. The rationale for each of these theses is described.

  12. TOPICAL REVIEW: Anatomical imaging for radiotherapy

    NASA Astrophysics Data System (ADS)

    Evans, Philip M.

    2008-06-01

    The goal of radiation therapy is to achieve maximal therapeutic benefit expressed in terms of a high probability of local control of disease with minimal side effects. Physically this often equates to the delivery of a high dose of radiation to the tumour or target region whilst maintaining an acceptably low dose to other tissues, particularly those adjacent to the target. Techniques such as intensity modulated radiotherapy (IMRT), stereotactic radiosurgery and computer planned brachytherapy provide the means to calculate the radiation dose delivery to achieve the desired dose distribution. Imaging is an essential tool in all state of the art planning and delivery techniques: (i) to enable planning of the desired treatment, (ii) to verify the treatment is delivered as planned and (iii) to follow-up treatment outcome to monitor that the treatment has had the desired effect. Clinical imaging techniques can be loosely classified into anatomic methods which measure the basic physical characteristics of tissue such as their density and biological imaging techniques which measure functional characteristics such as metabolism. In this review we consider anatomical imaging techniques. Biological imaging is considered in another article. Anatomical imaging is generally used for goals (i) and (ii) above. Computed tomography (CT) has been the mainstay of anatomical treatment planning for many years, enabling some delineation of soft tissue as well as radiation attenuation estimation for dose prediction. Magnetic resonance imaging is fast becoming widespread alongside CT, enabling superior soft-tissue visualization. Traditionally scanning for treatment planning has relied on the use of a single snapshot scan. Recent years have seen the development of techniques such as 4D CT and adaptive radiotherapy (ART). In 4D CT raw data are encoded with phase information and reconstructed to yield a set of scans detailing motion through the breathing, or cardiac, cycle. In ART a set of

  13. Radiotherapy Dose Fractionation under Parameter Uncertainty

    SciTech Connect

    Davison, Matt; Kim, Daero; Keller, Harald

    2011-11-30

    In radiotherapy, radiation is directed to damage a tumor while avoiding surrounding healthy tissue. Tradeoffs ensue because dose cannot be exactly shaped to the tumor. It is particularly important to ensure that sensitive biological structures near the tumor are not damaged more than a certain amount. Biological tissue is known to have a nonlinear response to incident radiation. The linear quadratic dose response model, which requires the specification of two clinically and experimentally observed response coefficients, is commonly used to model this effect. This model yields an optimization problem giving two different types of optimal dose sequences (fractionation schedules). Which fractionation schedule is preferred depends on the response coefficients. These coefficients are uncertainly known and may differ from patient to patient. Because of this not only the expected outcomes but also the uncertainty around these outcomes are important, and it might not be prudent to select the strategy with the best expected outcome.

  14. Nanoscale radiotherapy with hafnium oxide nanoparticles.

    PubMed

    Maggiorella, Laurence; Barouch, Gilles; Devaux, Corinne; Pottier, Agnès; Deutsch, Eric; Bourhis, Jean; Borghi, Elsa; Levy, Laurent

    2012-09-01

    There is considerable interest in approaches that could improve the therapeutic window of radiotherapy. In this study, hafnium oxide nanoparticles were designed that concentrate in tumor cells to achieve intracellular high-energy dose deposit. Conventional methods were used, implemented in different ways, to explore interactions of these high-atomic-number nanoparticles and ionizing radiation with biological systems. Using the Monte Carlo simulation, these nanoparticles, when exposed to high-energy photons, were shown to demonstrate an approximately ninefold radiation dose enhancement compared with water. Importantly, the nanoparticles show satisfactory dispersion and persistence within the tumor and they form clusters in the cytoplasm of cancer cells. Marked antitumor activity is demonstrated in human cancer models. Safety is similar in treated and control animals as demonstrated by a broad program of toxicology evaluation. These findings, supported by good tolerance, provide the basis for developing this new type of nanoparticle as a promising anticancer approach in human patients.

  15. The future of heavy ion radiotherapy.

    PubMed

    Jäkel, Oliver; Karger, Christian P; Debus, Jürgen

    2008-12-01

    Currently, there is an increasing interest in heavy ion radiotherapy (RT) and a number of new facilities are being installed in Europe and Japan. This development is accompanied by intensive technical, physical, and clinical research. The authors identify six research fields where progress is likely and propose a thesis on the expected achievements for each of the fields: (1) Synchrotrons with active energy variation and three-dimensional beam scanning will be the standard in ion beam RT. (2) Common standards for precise measurement, prescription, and reporting of dose will be available. (3) Intensity-modulated particle therapy will be state-of-the-art. (4) Time-adaptive treatments of moving targets will be feasible. (5) Therapeutic effectiveness of heavy ions will be known for the most important indications while cost effectiveness will remain to be shown. (6) The potential of high-linear energy transfer radiation will be known. The rationale for each of these theses is described.

  16. Emerging applications of stereotactic body radiotherapy.

    PubMed

    Lo, Simon S; Loblaw, Andrew; Chang, Eric L; Mayr, Nina A; Teh, Bin S; Huang, Zhibin; Yao, Min; Ellis, Rodney J; Biswas, Tithi; Sohn, Jason W; Machtay, Mitchell; Sahgal, Arjun

    2014-05-01

    Stereotactic body radiotherapy (SBRT) has been used extensively in patients with lung, liver and spinal tumors, and the treatment outcomes are very favorable. For certain conditions such as medically inoperable stage I non-small-cell lung cancer, liver and lung oligometastases, primary liver cancer and spinal metastases, SBRT is regarded as one of the standard therapies. In the recent years, the use of SBRT has been extended to other disease conditions and sites such as recurrent head and neck cancer, renal cell carcinoma, prostate cancer, adrenal metastasis, pancreatic cancer, gynecological malignancies, spinal cord compression, breast cancer, and stage II-III non-small-cell lung cancer. Preliminary data in the literature show promising results but the follow-up intervals are short for most studies. This paper will provide an overview of these emerging applications.

  17. Proton beam radiotherapy of uveal melanoma

    PubMed Central

    Damato, Bertil; Kacperek, Andrzej; Errington, Doug; Heimann, Heinrich

    2013-01-01

    Proton beam radiotherapy of uveal melanoma can be administered as primary treatment, as salvage therapy for recurrent tumor, and as neoadjuvant therapy prior to surgical resection. The physical properties of proton beams make it possible to deliver high-doses of radiation to the tumor with relative sparing of adjacent tissues. This form of therapy is effective for a wider range of uveal melanoma than any other modality, providing exceptionally-high rates of local tumor control. This is particularly the case with diffuse iris melanomas, many of which are unresectable. The chances of survival, ocular conservation, visual preservation and avoidance of iatrogenic morbidity depend greatly on the tumor size, location and extent. When treating any side-effects and/or complications, it is helpful to consider whether these are the result of collateral damage or persistence of the irradiated tumor (‘toxic tumor syndrome’). PMID:24227980

  18. Compact Electronic Gamma Source For Radiotherapy

    SciTech Connect

    Chen, A. X.; Antolak, A. J.; Raber, T. N.; Morse, D. H.; Leung, K.-N.

    2011-06-01

    A compact mono-energetic gamma source is being developed to replace the radiological sources used in radiotherapy and other medical instruments. The electronic gamma source utilizes low-energy nuclear reactions to generate gammas in the 0.5 to 1.0 MeV energy range. Independent control of the ion current and energy is achieved by decoupling the RF-driven ion source and pyroelectric crystal-based acceleration systems The ions are accelerated to voltages above 100 keV and bombard a reaction target to produce gammas. Thermal management of the pyroelectric crystal-based accelerator is achieved by convective dielectric fluid flow around the crystal. This approach provides better temperature uniformity in the crystal and higher dielectric strength for suppressing voltage breakdown and enabling faster thermal cycling rates.

  19. [Radiotherapy phase I trials' methodology: Features].

    PubMed

    Rivoirard, R; Vallard, A; Langrand-Escure, J; Guy, J-B; Ben Mrad, M; Yaoxiong, X; Diao, P; Méry, B; Pigne, G; Rancoule, C; Magné, N

    2016-12-01

    In clinical research, biostatistical methods allow the rigorous analysis of data collection and should be defined from the trial design to obtain the appropriate experimental approach. Thus, if the main purpose of phase I is to determine the dose to use during phase II, methodology should be finely adjusted to experimental treatment(s). Today, the methodology for chemotherapy and targeted therapy is well known. For radiotherapy and chemoradiotherapy phase I trials, the primary endpoint must reflect both effectiveness and potential treatment toxicities. Methodology should probably be complex to limit failures in the following phases. However, there are very few data about methodology design in the literature. The present study focuses on these particular trials and their characteristics. It should help to raise existing methodological patterns shortcomings in order to propose new and better-suited designs.

  20. Radiotherapy and Antiangiogenic TM in Lung Cancer

    PubMed Central

    Khan, Mohamed K; Miller, Meredith W; Taylor, Jeremy; Gill, Navkiranjit K; Dick, Robert D; Van Golen, Kenneth; Brewer, George J; Merajver, Sofia D

    2002-01-01

    Abstract Tetrathiomolybdate (TM) is a potent nontoxic orally delivered copper complexing agent under development for the last several years for the treatment of Wilson's disease. It has been shown to block angiogenesis in primary and metastatic tumors. Therefore, the combination of cytotoxic radiotherapy (RT) and antiangiogenic TM could target both the existing tumor and the tumor microvasculature in a comprehensive strategy. Using a Lewis lung high metastatic (LLHM) carcinoma mouse tumor model, we demonstrate that the combination of TM and RT is more effective than either used as monotherapy. We also show that their therapeutic effects are additive, with no additional toxicity. We show that TM has no significant cytotoxicity in vitro against LLHM tumor cells, further supporting the antiangiogenic mechanism for its action. PMID:11896571

  1. High-LET charged particle radiotherapy

    SciTech Connect

    Castro, J.R. . Research Medicine and Radiation Biophysics Div. California Univ., San Francisco, CA . Dept. of Radiation Oncology)

    1991-07-01

    The Department of Radiation Oncology at UCSF Medical Center and the Radiation Oncology Department at UC Lawrence Berkeley Laboratory have been evaluating the use of high LET charged particle radiotherapy in a Phase 1--2 research trial ongoing since 1979. In this clinical trail, 239 patients have received at least 10 Gy (physical) minimum tumor dose with neon ions, meaning that at least one-half of their total treatment was given with high-LET charged particle therapy. Ninety-one patients received all of their therapy with neon ions. Of the 239 patients irradiated, target sites included lesions in the skin, subcutaneous tissues, head and neck such as paranasal sinuses, nasopharynx and salivary glands (major and minor), skull base and juxtaspinal area, GI tract including esophagus, pancreas and biliary tract, prostate, lung, soft tissue and bone. Analysis of these patients has been carried out with a minimum followup period of 2 years.

  2. High-LET charged particle radiotherapy

    SciTech Connect

    Castro, J.R. |

    1991-07-01

    The Department of Radiation Oncology at UCSF Medical Center and the Radiation Oncology Department at UC Lawrence Berkeley Laboratory have been evaluating the use of high LET charged particle radiotherapy in a Phase 1--2 research trial ongoing since 1979. In this clinical trail, 239 patients have received at least 10 Gy (physical) minimum tumor dose with neon ions, meaning that at least one-half of their total treatment was given with high-LET charged particle therapy. Ninety-one patients received all of their therapy with neon ions. Of the 239 patients irradiated, target sites included lesions in the skin, subcutaneous tissues, head and neck such as paranasal sinuses, nasopharynx and salivary glands (major and minor), skull base and juxtaspinal area, GI tract including esophagus, pancreas and biliary tract, prostate, lung, soft tissue and bone. Analysis of these patients has been carried out with a minimum followup period of 2 years.

  3. Breast cellulitis after conservative surgery and radiotherapy

    SciTech Connect

    Rescigno, J.; McCormick, B.; Brown, A.E.; Myskowski, P.L. )

    1994-04-30

    Cellulitis is a previously unreported complication of conservative surgery and radiation therapy for early stage breast cancer. Patients who presented with breast cellulitis after conservative therapy are described. Eleven patients that developed cellulitis of the breast over a 38-month period of observation are the subject of this report. Clinical characteristics of patients with cellulitis and their treatment and outcome are reported. Potential patient and treatment-related correlates for the development of cellulitis are analyzed. The risk of cellulitis persists years after initial breast cancer therapy. The clinical course of the patients was variable: some patients required aggressive, long-duration antibiotic therapy, while others had rapid resolution with antibiotics. Three patients suffered from multiple episodes of cellulitis. Patients with breast cancer treated with conservative surgery and radiotherapy are at risk for breast cellulitis. Systematic characterization of cases of cellulitis may provide insight into diagnosis, prevention, and more effective therapy for this uncommon complication. 15 refs., 1 fig., 2 tabs.

  4. Intensity-Modulated Radiotherapy for Pancreatic Adenocarcinoma

    SciTech Connect

    Abelson, Jonathan A.; Murphy, James D.; Minn, Ann Yuriko; Chung, Melody; Fisher, George A.; Ford, James M.; Kunz, Pamela; Norton, Jeffrey A.; Visser, Brendan C.; Poultsides, George A.; Koong, Albert C.; Chang, Daniel T.

    2012-03-15

    Purpose: To report the outcomes and toxicities in patients treated with intensity-modulated radiotherapy (IMRT) for pancreatic adenocarcinoma. Methods and Materials: Forty-seven patients with pancreatic adenocarcinoma were treated with IMRT between 2003 and 2008. Of these 47 patients, 29 were treated adjuvantly