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Sample records for plaque radiation therapy

  1. Risk Factors for Cataract After Palladium-103 Ophthalmic Plaque Radiation Therapy

    SciTech Connect

    Finger, Paul T.; Chin, Kimberly J.; Yu Guopei; Patel, Neil S.

    2011-07-01

    Purpose: To examine how tumor characteristics and dose affect cataract development after plaque radiation therapy. Methods and Materials: Three hundred and eighty-four patients were diagnosed with uveal melanoma and treated with palladium-103 ({sup 103}Pd) plaque radiation therapy. Of these, 282 (74%) inclusion met exclusion criteria for follow-up time, tumor location, and phakic status. Then patient-, ophthalmic-, and radiation-specific factors (patient age, diabetes, hypertension, tumor location, tumor dimensions, and lens dose) were examined (by a Cox proportional regression model) as predictors for the development of radiation-related cataract. Results: Radiation cataract developed in 76 (24%) of patients at a mean follow-up of 39.8 months (range, 1-192). Patients with anteriorly located tumors were noted to have a higher incidence of cataract at 43.0% (43 of 100 patients) vs. 18.1% (33 cataracts per 182 patients) for posteriorly located tumors (p <0.0001). However, multivariate Cox proportional modeling showed that increasing patient age at time of treatment (p for trend = 0.0003) and higher lens dose (p for trend = 0.001) were the best predictors (biomarkers) for radiation cataract. Conclusions: Although anterior tumor location, greater tumor height, and increased patient age (at treatment) were associated with significantly greater risk for radiation cataract, dose to lens was the most significant factor.

  2. [{sup 18}F]Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (PET/CT) Physiologic Imaging of Choroidal Melanoma: Before and After Ophthalmic Plaque Radiation Therapy

    SciTech Connect

    Finger, Paul T.; Chin, Kimberly J.

    2011-01-01

    Purpose: To evaluate changes in [{sup 18}F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) standardized uptake values (SUV) in uveal melanoma before and after plaque brachytherapy. Methods and Materials: A cohort of 217 patients diagnosed with uveal melanoma and eligible for ophthalmic plaque brachytherapy underwent preoperative PET/CT to evaluate their intraocular tumor and screen for metastasis. Subsequent to undergoing plaque brachytherapy, patients' PET/CT SUV were periodically reevaluated over 42 months. Results: In this series, 37 (17%) choroidal melanoma patients were found to have an SUV of >2.0. Of these, 18 patients were able to undergo interval follow-up PET/CT scanning. There were 3 patients with T2, 11 patients with T3, and 4 patients with T4 melanomas according to 7th edition AJCC-UICC criteria. Mean apical thickness was 8.8 mm (range, 3-12.3 mm), and the largest mean tumor diameter was 15.1 mm (range, 12-19.9 mm). The mean initial SUV was 3.7 (range, 2.1-7.3). Patients were followed for a median 16 months (range, 6-42 months). The median time to a tumor SUV of 0 was 8.0 months (range, 6-18 months). There was one case of one interval increase in SUV that diminished after circumferential laser treatment. Conclusions: Intraocular PET/CT imaging provides a physiological assessment of tumor metabolism that can be used to evaluate changes after treatment. In this study, ophthalmic plaque radiation therapy was associated with extinguished tumor PET/CT SUV over time. PET/CT imaging can be used to assess choroidal melanomas for their response to treatment.

  3. Radiation regression patterns after cobalt plaque insertion for retinoblastoma

    SciTech Connect

    Buys, R.J.; Abramson, D.H.; Ellsworth, R.M.; Haik, B.

    1983-08-01

    An analysis of 31 eyes of 30 patients who had been treated with cobalt plaques for retinoblastoma disclosed that a type I radiation regression pattern developed in 15 patients; type II, in one patient, and type III, in five patients. Nine patients had a regression pattern characterized by complete destruction of the tumor, the surrounding choroid, and all of the vessels in the area into which the plaque was inserted. This resulting white scar, corresponding to the sclerae only, was classified as a type IV radiation regression pattern. There was no evidence of tumor recurrence in patients with type IV regression patterns, with an average follow-up of 6.5 years, after receiving cobalt plaque therapy. Twenty-nine of these 30 patients had been unsuccessfully treated with at least one other modality (ie, light coagulation, cryotherapy, external beam radiation, or chemotherapy).

  4. Radiation Therapy

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Radiation Therapy KidsHealth > For Teens > Radiation Therapy Print A ... how to cope with side effects. What Is Radiation Therapy? Cancer is a disease that causes cells ...

  5. A new inexpensive customized plaque for choroidal melanoma iodine-125 plaque therapy.

    PubMed

    Vine, A K; Tenhaken, R K; Diaz, R F; Maxson, B B; Lichter, A S

    1989-04-01

    The authors have developed a new inexpensive precious metal alloy plaque for use in customized iodine-125 plaque therapy. Each plaque is formed from two flat circular gold/palladium foils which are used in dental crown work. Using a simple manual mechanism, the two forms are stamped over a customized acrylic die shaped to the dimensions of the tumor base plus a 2-mm margin. Completed plaques consist of a back wall, a 2-mm side wall, and a 1.5-mm wide lip with holes for suture placement. Advantages include: simple construction from inexpensive components, customized shape, and iodine seeds that are readily visible on plane radiographs. PMID:2726186

  6. Radiation Therapy

    MedlinePlus

    Radiation therapy is a cancer treatment. It uses high doses of radiation to kill cancer cells and stop them from ... half of all cancer patients receive it. The radiation may be external, from special machines, or internal, ...

  7. Radiation therapy

    MedlinePlus

    Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells. ... faster than normal cells in the body. Because radiation is most harmful to quickly growing cells, radiation ...

  8. Dosimetric Benefit of a New Ophthalmic Radiation Plaque

    SciTech Connect

    Marwaha, Gaurav; Cleveland Clinic Foundation, Cleveland, Ohio ; Wilkinson, Allan; Cleveland Clinic Foundation, Cleveland, Ohio ; Bena, James; Cleveland Clinic Foundation, Cleveland, Ohio ; Macklis, Roger; Cleveland Clinic Foundation, Cleveland, Ohio ; Singh, Arun D.; Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio; Cleveland Clinic Foundation, Cleveland, Ohio

    2012-12-01

    Purpose: To determine whether the computed dosimetry of a new ophthalmic plaque, EP917, when compared with the standard Collaborative Ocular Melanoma Study (COMS) plaques, could reduce radiation exposure to vision critical structures of the eye. Methods and Materials: One hundred consecutive patients with uveal melanoma treated with COMS radiation plaques between 2007 and 2010 were included in this study. These treatment plans were generated with the use of Bebig Plaque Simulator treatment-planning software, both for COMS plaques and for EP917 plaques using I-125. Dose distributions were calculated for a prescription of 85 Gy to the tumor apex. Doses to the optic disc, opposite retina, lens, and macula were obtained, and differences between the 2 groups were analyzed by standard parametric methods. Results: When compared with the COMS plaques, the EP917 plaques used fewer radiation seeds by an average difference of 1.94 (P<.001; 95% confidence interval [CI], -2.8 to -1.06) and required less total strength of radiation sources by an average of 17.74 U (air kerma units) (P<.001; 95% CI, -20.16 to -15.32). The total radiation doses delivered to the optic disc, opposite retina, and macula were significantly less by 4.57 Gy, 0.50 Gy, and 11.18 Gy, respectively, with the EP917 plaques vs the COMS plaques. Conclusion: EP917 plaques deliver less overall radiation exposure to critical vision structures than COMS treatment plaques while still delivering the same total therapeutic dose to the tumor.

  9. Cobalt plaque therapy of posterior uveal melanomas

    SciTech Connect

    Shields, J.A.; Augsburger, J.J.; Brady, L.W.; Day, J.L.

    1982-10-01

    One hundred patients with choroidal melanomas who were treated by the authors with cobalt plaque radiotherapy were analyzed with regard to tumor regression, visual results, complications, and mortality rate. The follow-up period at the time of this writing ranged from one to five years. These preliminary observations indicate that cobalt plaque radiotherapy induces tumor regression in 96% of cases, preserves useful vision in many cases and has fewer complications during the one- to five-year follow-up period than previously believed.

  10. Identifying Vulnerable Plaques with Acoustic Radiation Force Impulse Imaging

    NASA Astrophysics Data System (ADS)

    Doherty, Joshua Ryan

    The rupture of arterial plaques is the most common cause of ischemic complications including stroke, the fourth leading cause of death and number one cause of long term disability in the United States. Unfortunately, because conventional diagnostic tools fail to identify plaques that confer the highest risk, often a disabling stroke and/or sudden death is the first sign of disease. A diagnostic method capable of characterizing plaque vulnerability would likely enhance the predictive ability and ultimately the treatment of stroke before the onset of clinical events. This dissertation evaluates the hypothesis that Acoustic Radiation Force Impulse (ARFI) imaging can noninvasively identify lipid regions, that have been shown to increase a plaque's propensity to rupture, within carotid artery plaques in vivo. The work detailed herein describes development efforts and results from simulations and experiments that were performed to evaluate this hypothesis. To first demonstrate feasibility and evaluate potential safety concerns, finite- element method simulations are used to model the response of carotid artery plaques to an acoustic radiation force excitation. Lipid pool visualization is shown to vary as a function of lipid pool geometry and stiffness. A comparison of the resulting Von Mises stresses indicates that stresses induced by an ARFI excitation are three orders of magnitude lower than those induced by blood pressure. This thesis also presents the development of a novel pulse inversion harmonic tracking method to reduce clutter-imposed errors in ultrasound-based tissue displacement estimates. This method is validated in phantoms and was found to reduce bias and jitter displacement errors for a marked improvement in image quality in vivo. Lastly, this dissertation presents results from a preliminary in vivo study that compares ARFI imaging derived plaque stiffness with spatially registered composition determined by a Magnetic Resonance Imaging (MRI) gold standard in human carotid artery plaques. It is shown in this capstone experiment that lipid filled regions in MRI correspond to areas of increased displacement in ARFI imaging while calcium and loose matrix components in MRI correspond to uniformly low displacements in ARFI imaging. This dissertation provides evidence to support that ARFI imaging may provide important prognostic and diagnostic information regarding stroke risk via measurements of plaque stiffness. More generally, the results have important implications for all acoustic radiation force based imaging methods used clinically.

  11. {sup 106}Ruthenium Plaque Therapy (RPT) for Retinoblastoma

    SciTech Connect

    Murakami, Naoya; Suzuki, Shigenobu; Ito, Yoshinori; Yoshimura, Ryoichi; Inaba, Koji; Kuroda, Yuki; Morota, Madoka; Mayahara, Hiroshi; Sakudo, Mototake; Wakita, Akihisa; Okamoto, Hiroyuki; Sumi, Minako; Kagami, Yoshikazu; Nakagawa, Keiichi; Ohtomo, Kuni; Itami, Jun

    2012-09-01

    Purpose: To evaluate the effectiveness of episcleral {sup 106}ruthenium plaque therapy (RPT) in the management of retinoblastoma. Methods and Materials: One hundred one RPTs were retrospectively analyzed that were performed in 90 eyes of 85 patients with retinoblastoma at National Cancer Center Hospital between 1998 and 2008. Each RPT had a corresponding tumor and 101 tumors were considered in the analysis of local control. Median follow-up length was 72.8 months. Median patient age at the RPT was 28 months. Median prescribed doses at reference depth and outer surface of the sclera were 47.4 Gy and 162.3 Gy, respectively. Results: Local control rate (LCR) and ocular retention rate (ORR) at 2 years were 33.7% and 58.7%, respectively. Unilateral disease, International Classification of Retinoblastoma group C or more advanced at the first presentation or at the time of RPT, vitreous and/or subretinal seeding, tumor size greater than 5 disc diameter (DD), reference depth greater than 5 mm, dose rate at reference depth lower than 0.7 Gy/hour, dose at the reference depth lower than 35 Gy, and (biologically effective dose with an {alpha}/{beta} ratio of 10 Gy) at the reference depth lower than 40 Gy{sub 10} were associated with unfavorable LCR. Two patients died of metastatic disease. Radiation complications included retinal detachment in 12 eyes (13.3%), proliferative retinopathy in 6 (6.7%), rubeosis iris in 2 (2.2%), and posterior subcapsular cataract in 23 (25.6%). Conclusion: RPT is an effective eye-preserving treatment for retinoblastoma.

  12. Radiation Therapy for Cancer

    MedlinePlus

    ... What is radiation therapy? Radiation therapy uses high-energy radiation to shrink tumors and kill cancer cells ( ... is a measure of the amount of radiation energy absorbed by 1 kilogram of human tissue. Different ...

  13. Radiation Therapy

    MedlinePlus

    ... three types of brachytherapy: Low-dose rate (LDR) implants In this type of brachytherapy, the radiation source ... the catheter or applicator. High-dose rate (HDR) implants In this type of brachytherapy, the radiation source ...

  14. Radiation Therapy

    MedlinePlus

    ... Radiation (also called x-rays, gamma rays, or photons) either kills tumor cells directly or interferes with ... treatment per day, five days a week, for two to seven weeks. Potiential Side Effects Most people ...

  15. Episcleral radioactive plaque therapy: Initial clinical experience with 56 patients

    SciTech Connect

    Lean, E.K.; Cohen, D.M.; Liggett, P.E.; Luxton, G.; Langholz, B.; Lau, R.; Astrahan, M.A.; Hyden, E.C.; Petrovich, Z. )

    1990-06-01

    Between 1983 and 1987, 56 patients with choroidal melanoma were treated at the University of Southern California with episcleral plaque (RPT). There were 29 female and 27 male patients, with a mean age of 59 years. Tumor stage at diagnosis was T2 in 18 (32%) and T3 in 38 (68%) patients. The tumor height ranged from 2.9 to 15 mm (mean 6.8 mm). Radial dimensions ranged from 5 to 25 mm (mean 13.2 mm), and circumference ranged from 7 to 23 mm (mean 12.3 mm). Most (77%) patients had posteriorly located tumors, including 18% that were juxtapapillary. Custom-designed gold plaques were utilized in this study. Radioactive isotopes used were 125I for 26 procedures or 192Ir for 31 procedures. A total of 56 patients were treated, with one patient having two procedures. Radiation doses at the tumor apex ranged from 29.8 to 165.4 Gy (mean 94.5 Gy), with the dose at 5-mm depth ranging from 70.5 to 430 Gy (mean 161.5 Gy). Follow-up ranged from 29 to 57 months (mean 39 months). The overall 4-year survival was 96%, with a 91% incidence of free-of-disease progression at 4 years. The majority (84%) of patients experienced a decrease in tumor height, with 27 (48%) patients having greater than 50% decrease. Increase in tumor height was noted in 5 (9%) and no change in 4 (7%) patients. Useful vision was observed in 59% of patients, including 21% who had improved vision. Metastatic tumor occurred in 5 (9%) patients, with a mean time to metastases of 14 months. There was a good correlation between radial tumor dimension and metastatic disease, p less than 0.001. Treatment complications were observed in 34 (61%) patients, with cataract and retinopathy being the most common. Enucleation was performed in 11 (20%) patients, with a mean time to enucleation of 14.5 months. Causative factors for enucleation were treatment complications in 6 and tumor progression in 5 patients.

  16. Radiation Therapy (For Parents)

    MedlinePlus

    ... work quickly to reduce exposure. previous continue Common Side Effects of Radiation If your child has cancer, you' ... lotions to the treated area. previous continue Common Side Effects of Radiation (continued) Hair Loss Radiation therapy to ...

  17. Radiation complications and tumor control after {sup 125}I plaque brachytherapy for ocular melanoma

    SciTech Connect

    Jensen, Ashley W.; Petersen, Ivy A. . E-mail: petersen.ivy@mayo.edu; Kline, Robert W.; Stafford, Scott L.; Schomberg, Paula J.; Robertson, Dennis M.

    2005-09-01

    Purpose: To determine the outcome of {sup 125}I plaque brachytherapy at our institution and identify the risk factors associated with the development of radiation complications, tumor recurrence, and metastasis. Patients and Methods: From 1986 to 2000, 156 patients underwent {sup 125}I episcleral plaque (COMS design) application for the treatment of ocular melanoma. Chart analysis of follow-up ophthalmologic appointments assessed the incidence of ocular side effects after therapy. Statistical analysis assessed outcomes and significant influencing factors. Results: With a median follow-up of 6.2 years, the 5-year overall survival was 83%. The 5-year disease-specific survival was 91%. Initial local control at 5 years was 92%, with 100% ultimate local control after secondary therapy that included 9 enucleations. The risk of metastasis was 10% at 5 years and 27% at 10 years. Vision stayed the same or improved in 25% of patients, and 44% of patients maintained visual acuity better than 20/200. Thirteen percent of patients experienced chronic pain or discomfort in the treated eye. Dose rates to the tumor apex greater than 90 to 100 cGy/h were associated with increased systemic control but worse radiation toxicity. Conclusion: Patients in our series experienced excellent local tumor control. Higher dose rates to the tumor apex were associated with reduced rates of distant metastases but worse ocular function.

  18. Serial Intravitreal Bevacizumab Injections Slow the Progression of Radiation Maculopathy Following Iodine-125 Plaque Radiotherapy

    PubMed Central

    Stacey, Andrew W.; Demirci, Hakan

    2016-01-01

    Background and Objective: To assess the outcomes of intravitreal bevacizumab injection in the management of radiation maculopathy secondary to plaque radiotherapy, and to identify optimal treatment strategies. Study Design: A retrospective review of all choroidal melanoma patients at one referral center who were treated with plaque radiotherapy, subsequently developed radiation maculopathy, and received intravitreal bevacizumab. Results: A total of 31 patients were identified. The mean visual acuity decreased three Snellen lines in the year leading up to the first bevacizumab injection. After initiating injection therapy, the mean visual acuity remained stable for 9 months. The change in visual acuity of patients who received injections within 90 days of previous injections was significantly better than the visual acuity of those who received injections more than 90 days apart (p=0.0003). Patients who demonstrated late-phase macular leakage on fluorescein angiography at the time of the first bevacizumab injection had better long-term visual acuity outcomes than patients who had no evidence of macular leakage (average of one line improvement of vision vs. ten line loss of vision, p=0.03). Conclusions: Intravitreal bevacizumab injection was effective in stabilizing visual acuity in patients with radiation maculopathy. Patients benefited most from injections administered every 90 days or sooner. Fluorescein angiography can help identify patients who will respond favorably to treatment. PMID:27053973

  19. Rapid stabilisation of atherosclerotic plaque with 5-aminolevulinic acid-mediated sonodynamic therapy.

    PubMed

    Li, Zhitao; Sun, Xin; Guo, Shuyuan; Wang, Liping; Wang, Tengyu; Peng, Chenghai; Wang, Wei; Tian, Zhen; Zhao, Ruibo; Cao, Wenwu; Tian, Ye

    2015-10-01

    5-Aminolevulinic acid-mediated sonodynamic therapy (ALA-SDT) effectively induces the apoptosis of atherogenic macrophages, but whether it can stabilise atherosclerotic plaque in vivo is unclear. Here, we used an animal model to evaluate the effects of ALA-SDT on plaque stabilisation. Sixty rabbits were induced atherosclerotic plaques in the femoral artery with a combination of silastic tube placement with atherogenic diet, and randomly assigned into control (n = 12) and SDT (n = 48) groups. In the SDT group, after intravenous injected with ALA (60 mg/kg) animals underwent the treatment of ultrasound with intensities of 0.75, 1.00, 1.50 and 2.00 W/cm(²) (n = 12 for each intensity). Seven days after the treatment, the plaque disruption assay was performed to test plaque stability. We found that ALA-SDT with ultrasound intensity of 1.5 W/cm(²) showed the strongest efficacy to stabilise plaques. Under this condition, the frequency of plaque disruption decreased by 88% (p<0.01), positive area of macrophages reduced by 94% (p<0.001) and percentage content of lipids dropped by 60% (p < 0.001), while percentage content of collagens increased by 127% (p<0.001). We also found that the plaque stabilisation by ALA-SDT was associated with increased macrophage apoptosis and apoptotic cell clearance. Moreover, ALA-SDT decreased the contents and activities of matrix metalloproteinase-2,9 and increased the levels of tissue inhibitors of matrix metalloproteinase-1,2 in plaques. Our studies demonstrate that ALA-SDT promotes plaque stabilisation by inducing macrophage elimination and inhibiting matrix degradation. This method might be a promising regimen for atherosclerosis therapy. PMID:26179778

  20. Radiation Therapy: Additional Treatment Options

    MedlinePlus

    ... Upper GI What is Radiation Therapy? Find a Radiation Oncologist Last Name: Facility: City: State: Zip Code: ... infections. This is refered to as immunotherapy . Intraoperative Radiation Therapy Radiation therapy given during surgery is called ...

  1. Radiation therapy - skin care

    MedlinePlus

    ... red, peel, or itch. You should treat your skin with care while receiving radiation therapy. ... When you have radiation treatment, a health care provider draws ... they come off, do not redraw them. Tell your provider instead. ...

  2. Microenvironment and Radiation Therapy

    PubMed Central

    Yoshimura, Michio; Itasaka, Satoshi; Harada, Hiroshi; Hiraoka, Masahiro

    2013-01-01

    Dependency on tumor oxygenation is one of the major features of radiation therapy and this has led many radiation biologists and oncologists to focus on tumor hypoxia. The first approach to overcome tumor hypoxia was to improve tumor oxygenation by increasing oxygen delivery and a subsequent approach was the use of radiosensitizers in combination with radiation therapy. Clinical use of some of these approaches was promising, but they are not widely used due to several limitations. Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that is activated by hypoxia and induces the expression of various genes related to the adaptation of cellular metabolism to hypoxia, invasion and metastasis of cancer cells and angiogenesis, and so forth. HIF-1 is a potent target to enhance the therapeutic effects of radiation therapy. Another approach is antiangiogenic therapy. The combination with radiation therapy is promising, but several factors including surrogate markers, timing and duration, and so forth have to be optimized before introducing it into clinics. In this review, we examined how the tumor microenvironment influences the effects of radiation and how we can enhance the antitumor effects of radiation therapy by modifying the tumor microenvironment. PMID:23509762

  3. Radiation Therapy for Testicular Cancer

    MedlinePlus

    ... chemo and stem cell transplant for testicular cancer Radiation therapy for testicular cancer Radiation therapy uses high-energy rays or particles to ... cells or slow their growth. In testicular cancer, radiation is mainly used to kill cancer cells that ...

  4. Bile Duct (Cholangiocarcinoma) Cancer: Radiation Therapy

    MedlinePlus

    ... cancer Next Topic Chemotherapy for bile duct cancer Radiation therapy for bile duct cancer Radiation therapy uses ... of radiation for bile duct cancer. External beam radiation therapy (EBRT) This type of radiation therapy uses ...

  5. Antioxidants attenuate atherosclerotic plaque development in a balloon-denuded and -radiated hypercholesterolemic rabbit

    SciTech Connect

    Leborgne, Laurent; Fournadjiev, Jana; Pakala, Rajbabu; Dilcher, Christian; Cheneau, Edouard; Wolfram, Roswitha; Hellinga, David; Seaborn, Rufus; O'Tio, Fermin; Waksman, Ron

    2003-03-01

    Background: Oxidation of lipoproteins is considered to be a key contributor to atherogenesis. Antioxidants are potential antiatherogenic agents because they can inhibit lipoprotein oxidation. Radiation has been shown to increase oxidative stress leading to increased atherogenesis. This study is designed to test the potential of antioxidants to inhibit atherosclerotic plaque progression in balloon-denuded and -radiated rabbits. Methods and Results: Two groups of New Zealand white rabbits (n=36) were fed with 1% cholesterol diet (control diet) or with 1% cholesterol diet containing a mixture of various antioxidants for 1 week. Iliac arteries in all the animals were balloon denuded and continued to fed with 0.15% cholesterol diet or 0.15% cholesterol diet containing antioxidants (antioxidant diet). Four weeks after balloon denudation one iliac artery in 12 animals from each group was radiated and all the animals were continued to be fed with the same diet. Four weeks after radiation animals were sacrificed and morphometric analysis of iliac arteries (n=12) in nonradiated and radiated animals were performed. Plaque area (PA) in the rabbits that were fed with cholesterol diet is 0.2{+-}0.12 mm{sup 2}, and it is increased by 2.75-fold (P<.05) in the radiated arteries of animals fed with cholesterol diet. Plaque area in the animals fed with antioxidant diet is 50% less then the one in the animals fed with cholesterol diet. Similarly, plaque area in radiated arteries of the animals fed with antioxidant diet is 50% less then the animals fed with cholesterol diet. Conclusion: Antioxidants significantly attenuate atherosclerotic plaque progression in balloon-injured and -radiated hypercholesterolemic rabbits.

  6. Acoustic radiation force impulse imaging of vulnerable plaques: a finite element method parametric analysis

    PubMed Central

    Doherty, Joshua R.; Dumont, Douglas M.; Trahey, Gregg E.; Palmeri, Mark L.

    2012-01-01

    Plaque rupture is the most common cause of complications such as stroke and coronary heart failure. Recent histopathological evidence suggests that several plaque features, including a large lipid core and a thin fibrous cap, are associated with plaques most at risk for rupture. Acoustic Radiation Force Impulse (ARFI) imaging, a recently developed ultrasound-based elasticity imaging technique, shows promise for imaging these features noninvasively. Clinically, this could be used to distinguish vulnerable plaques, for which surgical intervention may be required, from those less prone to rupture. In this study, a parametric analysis using Finite-Element Method (FEM) models was performed to simulate ARFI imaging of five different carotid artery plaques across a wide range of material properties. It was demonstrated that ARFI could resolve the softer lipid pool from the surrounding, stiffer media and fibrous cap and was most dependent upon the stiffness of the lipid pool component. Stress concentrations due to an ARFI excitation were located in the media and fibrous cap components. In all cases, the maximum Von Mises stress was < 1.2 kPa. In comparing these results with others investigating plaque rupture, it is concluded that while the mechanisms may be different, the Von Mises stresses imposed by ARFI are orders of magnitude lower than the stresses associated with blood pressure. PMID:23122224

  7. Noncontiguous local recurrence of posterior uveal melanoma after cobalt 60 episcleral plaque therapy

    SciTech Connect

    Duker, J.S.; Augsburger, J.J.; Shields, J.A.

    1989-07-01

    Four patients with posterior uveal melanomas treated by cobalt 60 episcleral plaque therapy developed the intraocular recurrence of choroidal melanoma at a site distant from and noncontiguous to their original lesions. Three of the four patients died of metastatic melanoma. The proportion of eyes with posterior uveal melanoma treated with cobalt 60 brachytherapy who subsequently develop this type of local recurrence appears to be low (0.68%).

  8. Apremilast and Secukinumab Combined Therapy in a Patient With Recalcitrant Plaque Psoriasis.

    PubMed

    Rothstein, Brooke E; McQuade, Brianna; Greb, Jacqueline E; Goldminz, Ari M; Gottlieb, Alice B

    2016-05-01

    We report a 67-year-old Caucasian man with a long-term history of recalcitrant plaque psoriasis and psoriatic arthritis who was initiated on a treatment regimen of apremilast and secukinumab after failing multiple topical, photo, and systemic therapies. This combination provided significant skin improvement with minimal drug side effects.

    J Drugs Dermatol. 2016;15(5):648-649. PMID:27168275

  9. Radiation Therapy for Soft Tissue Sarcomas

    MedlinePlus

    ... sarcomas Next Topic Chemotherapy for soft tissue sarcomas Radiation therapy for soft tissue sarcomas Radiation therapy uses ... spread. This is called palliative treatment . Types of radiation therapy External beam radiation therapy: For this treatment, ...

  10. Candidal carriage and plaque distribution before, during and after removable orthodontic appliance therapy.

    PubMed

    Arendorf, T; Addy, M

    1985-05-01

    Candidal counts at 6 mucosal sites in 33 subjects were estimated by imprint culture before, during and after removable orthodontic appliance therapy. Additionally, dental plaque scores and salivary pH were measured at each stage. Whole mouth and site prevalence of candida rose significantly during therapy before falling to levels approximating initial values. A similar pattern was seen for candidal counts for the whole mouth and at individual mucosal sites, although post-treatment densities were usually lower than originally seen. The number of sites colonised by candida and salivary pH also increased significantly during treatment and fell significantly afterwards. Only the upper palatal plaque scores rose during therapy and most other dental sites showed a gradual decrease in value during the course of the study. This could be attributed to regular monitoring of the patient's oral hygiene procedures. This investigation demonstrated a direct relationship between the presence of an acrylic appliance, candida and low salivary pH levels. Furthermore, removable appliance therapy had a positive, though transient influence upon the prevalence and density of oral candidal carriage, suggesting that the appliance may initiate the carrier state. PMID:3859496

  11. Ultrasound Assessment of Carotid Plaque Echogenicity Response to Statin Therapy: A Systematic Review and Meta-Analysis

    PubMed Central

    Ibrahimi, Pranvera; Jashari, Fisnik; Bajraktari, Gani; Wester, Per; Henein, Michael Y.

    2015-01-01

    Objective: To evaluate in a systematic review and meta-analysis model the effect of statin therapy on carotid plaque echogenicity assessed by ultrasound. Methods: We have systematically searched electronic databases (PubMed, MEDLINE, EMBASE and Cochrane Center Register) up to April, 2015, for studies evaluating the effect of statins on plaque echogenicity. Two researchers independently determined the eligibility of studies evaluating the effect of statin therapy on carotid plaque echogenicity that used ultrasound and grey scale median (GSM) or integrated back scatter (IBS). Results: Nine out of 580 identified studies including 566 patients’ carotid artery data were meta-analyzed for a mean follow up of 7.2 months. A consistent increase in the echogenicity of carotid artery plaques, after statin therapy, was reported. Pooled weighted mean difference % (WMD) on plaque echogenicity after statin therapy was 29% (95% CI 22%–36%), p < 0.001, I2 = 92.1%. In a meta-regression analysis using % mean changes of LDL, HDL and hsCRP as moderators, it was shown that the effects of statins on plaque echogenicity were related to changes in hsCRP, but not to LDL and HDL changes from the baseline. The effect of statins on the plaque was progressive; it showed significance after the first month of treatment, and the echogenicity continued to increase in the following six and 12 months. Conclusions: Statin therapy is associated with a favorable increase of carotid plaque echogenicity. This effect seems to be dependent on the period of treatment and hsCRP change from the baseline, independent of changes in LDL and HDL. PMID:25984600

  12. [Problems after radiation therapy].

    PubMed

    Karasawa, Kumiko

    2014-01-01

    The rate of severe late adverse effects has decreased with the highly accurate administration of radiation therapy; however, the total number of patients who suffer from late effects has not decreased because of the increased total number of patients and better survival rates. Late adverse effects, occurring more than a few months after irradiation, include the extension and collapse of capillaries, thickening of the basement membrane, and scarring of tissue due to loss of peripheral vessels. The main causes of these late effects are the loss of stromal cells and vascular injury. This is in contrast to early reactions, which occur mainly due to the reorganization of slow-growing non-stem cell renewal systems such as the lung, kidney, heart, and central nervous system. In addition, the patient's quality of life is impaired if acute reactions such as mouth or skin dryness are not alleviated. Most adverse effects are radiation dose dependent, and the thresholds differ according to the radiosensitivity of each organ. These reactions occur with a latency period of a few months to more than 10 years. Understanding the clinical and pathological status, through discussion with radiation oncologists, is the essential first step. Some of the late effects have no effective treatment, but others can be treated by steroids or hyperbaric oxygen therapy. An appropriate decision is important. PMID:24423950

  13. Calcipotriol plus short-contact dithranol: a novel topical combination therapy for chronic plaque psoriasis.

    PubMed

    Monastirli, A; Georgiou, S; Pasmatzi, E; Sakkis, Th; Badavanis, G; Drainas, D; Sagriotis, A; Tsambaos, D

    2002-01-01

    The purpose of this double-blind randomised parallel-group study was to compare the efficacy and safety of short-contact treatment with dithranol ointment (2%) with its combination with calcipotriol ointment (50 microg/g) in 2 groups of in-patients with chronic plaque psoriasis. The patients of the first group (n = 23) topically applied dithranol once daily for 30 min and the vehicle of calcipotriol twice daily. The patients of the second group (n = 23) used a single topical application of dithranol for 30 min daily and additionally applied calcipotriol twice daily. The extent and the severity of psoriasis were assessed by means of psoriasis area and severity index score (PASI score) before the onset of the 6-week therapy and weekly thereafter. The difference between the two groups with regard to the mean PASI score became statistically significant already after the first week of treatment and remained so until the end of the trial. No significant differences were observed between the two groups with respect to the cutaneous adverse events. These findings indicate that the addition of calcipotriol ointment to short-contact dithranol markedly augments the therapeutic efficacy of the latter in chronic plaque psoriasis and impressively accelerates the response of psoriatic plaques to this well-tolerated regimen. PMID:12218286

  14. Radiation Therapy for Gynecologic Cancers

    MedlinePlus

    ... care for yourself as well as possible during radiation therapy because the normal parts of your body ... are near the tumor are also receiving some radiation, although not as much as the cancer. These ...

  15. Radiation Therapy for Skin Cancer

    MedlinePlus

    LEARNING ABOUT CLINICAL TRIALS The radiation oncology treatment team is constantly exploring new ways to treat cancer through studies called clinical trials. Today’s standard radiation therapy treatments ...

  16. Noninvasive In Vivo Characterization of Human Carotid Plaques with Acoustic Radiation Force Impulse (ARFI) Ultrasound: Comparison with Histology Following Endarterectomy

    PubMed Central

    Czernuszewicz, Tomasz J.; Homeister, Jonathon W.; Caughey, Melissa C.; Farber, Mark A.; Fulton, Joseph J.; Ford, Peter F.; Marston, William A.; Vallabhaneni, Raghuveer; Nichols, Timothy C.; Gallippi, Caterina M.

    2014-01-01

    Ischemic stroke from thromboembolic sources is linked to carotid artery atherosclerotic disease with a trend toward medical management in asymptomatic patients. Extent of disease is currently diagnosed by noninvasive imaging techniques that measure luminal stenosis, but it has been suggested that a better biomarker for determining risk of future thromboembolic events is plaque morphology and composition. Specifically, plaques that are composed of mechanically-soft lipid/necrotic regions covered by thin fibrous caps are the most vulnerable to rupture. An ultrasound technique that noninvasively interrogates the mechanical properties of soft tissue, called acoustic radiation force impulse (ARFI) imaging, has been developed as a new modality for atherosclerotic plaque characterization using phantoms and atherosclerotic pigs, but the technique has yet to be validated in vivo in humans. In this preliminary study, in vivo ARFI imaging is presented in a case-study format from four patients undergoing clinically-indicated carotid endarterectomy and compared to histology. In two type Va plaques, characterized by lipid/necrotic cores covered by fibrous caps, mean ARFI displacements in focal regions were high relative to the surrounding plaque material, suggesting soft features covered by stiffer layers within the plaques. In two type Vb plaques, characterized by heavy calcification, mean ARFI peak displacements were low relative to the surrounding plaque and arterial wall, suggesting stiff tissue. This pilot study demonstrates the feasibility and challenges of transcutaneous ARFI for characterizing the material and structural composition of carotid atherosclerotic plaques via mechanical properties, in humans, in vivo. PMID:25619778

  17. Novel anti-microbial therapies for dental plaque-related diseases.

    PubMed

    Allaker, Robert P; Douglas, C W Ian

    2009-01-01

    Control of dental plaque-related diseases has traditionally relied on non-specific removal of plaque by mechanical means. As our knowledge of oral disease mechanisms increases, future treatment is likely to be more targeted, for example at small groups of organisms, single species or at key virulence factors they produce. The aim of this review is to consider the current status as regards novel treatment approaches. Maintenance of oral hygiene often includes use of chemical agents; however, increasing problems of resistance to synthetic antimicrobials have encouraged the search for alternative natural products. Plants are the source of more than 25% of prescription and over-the-counter preparations, and the potential of natural agents for oral prophylaxis will therefore be considered. Targeted approaches may be directed at the black-pigmented anaerobes associated with periodontitis. Such pigments provide an opportunity for targeted phototherapy with high-intensity monochromatic light. Studies to date have demonstrated selective killing of Porphyromonas gingivalis and Prevotella intermedia in biofilms. Functional inhibition approaches, including the use of protease inhibitors, are also being explored to control periodontitis. Replacement therapy by which a resident pathogen is replaced with a non-pathogenic bacteriocin-producing variant is currently under development with respect to Streptococcus mutans and dental caries. PMID:18804350

  18. Lack of Radiation Maculopathy After Palladium-103 Plaque Radiotherapy for Iris Melanoma

    SciTech Connect

    Yousef, Yacoub A.; Finger, Paul T.

    2012-07-15

    Purpose: To report on the risk of radiation maculopathy for iris and iridociliary melanomas treated by {sup 103}Pd plaque radiotherapy. Methods and Materials: This is a retrospective clinical case series of 30 eyes in 30 patients with melanomas limited to the iris or invading the ciliary body. The main outcome measures included demographic information, laterality, tumor size, location, visual acuity, radiation dose, local control, retinal evaluation, and duration of follow-up. Results: Thirty patients were followed for a median 36 months (range, 12-90 months). Sixteen of 30 tumors (53%) were pure iris melanomas, and 14 (47%) were primary iris melanomas extending into the ciliary body. Radiation dosimetry showed that the median tumor apex dose was 85 Gy (range, 75-100 Gy), lens dose 43.5 Gy (range, 17.8-60 Gy), fovea dose 1.8 Gy (range, 1.3-5 Gy), and central optic disc dose 1.7 Gy (range, 1.3-4.7 Gy). Cataracts developed in 20 of the 28 phakic eyes (71.4%). No patient in this series developed radiation maculopathy or radiation optic neuropathy. Last best-corrected visual acuity was {>=}20/25 in 28 patients (93%) at a median 36 months' follow-up. Conclusion: Though visual acuities were transiently affected by radiation cataract, no radiation maculopathy or optic neuropathy has been noted after {sup 103}Pd treatment of iris and iridociliary melanomas.

  19. Direct photodynamic therapy for vulnerable plaque: investigation of light dosimetry for depth control

    NASA Astrophysics Data System (ADS)

    Ohmori, Sayaka; Yanagihara, Takeshi; Arai, Tsunenori

    2004-07-01

    Photodynamic therapy (PDT) mechanism with high-intensity pulsed laser excitation has not been well understood. We think complete understanding of this unknown effect in PDT leads perfect treated depth control at various lesions. To realize the depth controlled PDT for atheromatous plaque therapy with a fibrous cap intact and surrounding damage free, we studied PDT against murine macrophage-like cells in vitro with the second-generation chlorin photosensitizer manufactured by Photochemical Co. Ltd. (Okayama Japan). The relation between the excitation conditions (pulse energy density and repetition rate) and PDT photocytotoxicity was examined in vitro. The XeCl excimer laser pumped dye laser (wavelength: 669+/-3 nm, pulse duration: 7ns in FWHM) was used with the pulse energy density from 1.2 to 9.5 mJ/cm2, and the pulse repetition rate from 5 to 80 Hz. Under higher pulse energy density condition, no significant PDT photocytotoxicity was obtained. We examined the photobleaching of the protein containing photosensitizer medium solution, which is considered to correlates with the generation of singlet oxygen. Under higher pulse energy condition, the photobleaching efficiency decrease was observed and the measured PDT effect decrease in terms of laser pulse energy density could be explained by the photobleaching. We measured the oxygen partial pressure in photosensitizer medium solution immediately after the laser exposure. The decrease of oxygen partial pressure, i.e., the amount of the oxygen consumption during the laser exposure was observed 46 mmHg under the excitation condition of the pulse energy density of 9.5 mJ/cm2, the total fluence of 5 J/cm2, the repetition rate of 80Hz, and correlated with the bleaching efficiency 87% under the same condition. We calculated cell death distribution in depth direction based on measured photocytotoxicity under various pulse energy densities. The possibility of depth controlled PDT for safety atheromatous plaque therapy was suggested by the PDT effect alteration depending on pulse energy density.

  20. Long-term Results of the UCSF-LBNL Randomized Trial: Charged Particle With Helium Ion Versus Iodine-125 Plaque Therapy for Choroidal and Ciliary Body Melanoma

    SciTech Connect

    Mishra, Kavita K.; Quivey, Jeanne M.; Daftari, Inder K.; Weinberg, Vivian; Cole, Tia B.; Patel, Kishan; Castro, Joseph R.; Phillips, Theodore L.; Char, Devron H.

    2015-06-01

    Purpose: Relevant clinical data are needed given the increasing national interest in charged particle radiation therapy (CPT) programs. Here we report long-term outcomes from the only randomized, stratified trial comparing CPT with iodine-125 plaque therapy for choroidal and ciliary body melanoma. Methods and Materials: From 1985 to 1991, 184 patients met eligibility criteria and were randomized to receive particle (86 patients) or plaque therapy (98 patients). Patients were stratified by tumor diameter, thickness, distance to disc/fovea, anterior extension, and visual acuity. Tumors close to the optic disc were included. Local tumor control, as well as eye preservation, metastases due to melanoma, and survival were evaluated. Results: Median follow-up times for particle and plaque arm patients were 14.6 years and 12.3 years, respectively (P=.22), and for those alive at last follow-up, 18.5 and 16.5 years, respectively (P=.81). Local control (LC) for particle versus plaque treatment was 100% versus 84% at 5 years, and 98% versus 79% at 12 years, respectively (log rank: P=.0006). If patients with tumors close to the disc (<2 mm) were excluded, CPT still resulted in significantly improved LC: 100% versus 90% at 5 years and 98% versus 86% at 12 years, respectively (log rank: P=.048). Enucleation rate was lower after CPT: 11% versus 22% at 5 years and 17% versus 37% at 12 years, respectively (log rank: P=.01). Using Cox regression model, likelihood ratio test, treatment was the most important predictor of LC (P=.0002) and eye preservation (P=.01). CPT was a significant predictor of prolonged disease-free survival (log rank: P=.001). Conclusions: Particle therapy resulted in significantly improved local control, eye preservation, and disease-free survival as confirmed by long-term outcomes from the only randomized study available to date comparing radiation modalities in choroidal and ciliary body melanoma.

  1. Radiation safety consideration during intraoperative radiation therapy.

    PubMed

    Mobit, Paul N; Rajaguru, Priyadarshini; Brewer, Michael; Baird, Michael; Packianathan, Satyaseelan; Yang, Claus Chunli

    2015-04-01

    Using in-house-designed phantoms, the authors evaluated radiation exposure rates in the vicinity of a newly acquired intraoperative radiation therapy (IORT) system: Axxent Electronic Brachytherapy System. The authors also investigated the perimeter radiation levels during three different clinical intraoperative treatments (breast, floor of the mouth and bilateral neck cancer patients). Radiation surveys during treatment delivery indicated that IORT using the surface applicator and IORT using balloons inserted into patient body give rise to exposure rates of 200 mR h(-1), 30 cm from a treated area. To reduce the exposure levels, movable lead shields should be used as they reduce the exposure rates by >95%. The authors' measurements suggest that intraoperative treatment using the 50-kVp X-ray source can be administered in any regular operating room without the need for radiation shielding modification as long as the operators utilise lead aprons and/or stand behind lead shields. PMID:25267855

  2. External Radiation Therapy

    MedlinePlus Videos and Cool Tools

    Narrator: When the cancer is not completely contained in the prostate or when the patient is older the treatment that is frequently used ... There are different forms of radiation for prostate cancer. They really boil down to two different types. ...

  3. Method for microbeam radiation therapy

    DOEpatents

    Slatkin, D.N.; Dilmanian, F.A.; Spanne, P.O.

    1994-08-16

    A method is disclosed of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation. The dose is in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue. No Drawings

  4. Method for microbeam radiation therapy

    DOEpatents

    Slatkin, Daniel N.; Dilmanian, F. Avraham; Spanne, Per O.

    1994-01-01

    A method of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation, in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue.

  5. Intensity-modulated radiation therapy.

    PubMed

    Goffman, Thomas E; Glatstein, Eli

    2002-07-01

    Intensity-modulated radiation therapy (IMRT) is an increasingly popular technical means of tightly focusing the radiation dose around a cancer. As with stereotactic radiotherapy, IMRT uses multiple fields and angles to converge on the target. The potential for total dose escalation and for escalation of daily fraction size to the gross cancer is exciting. The excitement, however, has greatly overshadowed a range of radiobiological and clinical concerns. PMID:12071811

  6. The Effect of Statin Therapy on Coronary Plaque Composition Using Virtual Histology Intravascular Ultrasound: A Meta-Analysis

    PubMed Central

    Zheng, Guian; Li, Yuxin; Huang, Huishan; Wang, Jinghan; Hirayama, Atsushi; Lin, Jinxiu

    2015-01-01

    Objective Previous studies have indicated that statin therapy may promote plaque regression. However, the impact of statin therapy on plaque composition has not been clearly elucidated. We performed a meta-analysis to investigate the effect of statin therapy on coronary plaque composition as assessed by virtual histology intravascular ultrasound (VH-IVUS). Methods Online databases were searched from inception to March 1, 2015. Studies providing VH-IVUS volumetric analyses of coronary plaque composition at baseline and follow-up in patients receiving statin therapy were included. Weighted mean difference (WMD) using a random-effects model was used. Results Ten studies involving 682 patients were included. There was a substantial reduction in fibrous volume between baseline and follow-up (WMD: -2.37 mm3, 95% confidence interval (CI) -4.01 to -0.74 mm3, P=0.004), and a significant increase in dense calcium (DC) volume (WMD: 0.89 mm3, 95% CI 0.70 to 1.08 mm3, P<0.00001). No significant change was seen in fibro-fatty and necrotic core (NC) volumes. In stratified analyses, the fibrous volume was decreased significantly (WMD: -3.39 mm3, 95% CI -6.56 to -0.21 mm3, P=0.04) and the absolute DC volume (WMD: 0.99 mm3, 95% CI 0.23 to 1.76 mm3, P=0.01) was increased in the subgroup with ≥12 months follow-up, whereas no significant change was observed in the subgroup with < 12 months follow-up. Similarly, a substantial decrease in fibrous volume (WMD: -2.01 mm3, 95% CI -3.05 to -0.96 mm3, P< 0.0002) and an increase in DC volume (WMD: 0.90 mm3, 95% CI 0.70 to 1.10 mm3, P< 0.00001) were observed in the subgroup with high-intensive statin therapy, while the change in fibrous and DC volumes approached statistical significance (P=0.05 and P=0.05, respectively) in the subgroup with low-intensive statin therapy. Conclusions Statin treatment, particularly of high-intensity and long-term duration, induced a marked modification in coronary plaque composition including a decrease in fibrous tissue and an increase in DC. PMID:26225936

  7. Cancer Treatment with Gene Therapy and Radiation Therapy

    PubMed Central

    Kaliberov, Sergey A.; Buchsbaum, Donald J.

    2013-01-01

    Radiation therapy methods have evolved remarkably in recent years which have resulted in more effective local tumor control with negligible toxicity of surrounding normal tissues. However, local recurrence and distant metastasis often occur following radiation therapy mostly due to the development of radioresistance through the deregulation of the cell cycle, apoptosis, and inhibition of DNA damage repair mechanisms. Over the last decade, extensive progress in radiotherapy and gene therapy combinatorial approaches has been achieved to overcome resistance of tumor cells to radiation. In this review, we summarize the results from experimental cancer therapy studies on the combination of radiation therapy and gene therapy. PMID:23021246

  8. Radiation therapy of esophageal cancer

    SciTech Connect

    Hancock, S.L.; Glatstein, E.

    1984-06-01

    Radiation therapy has been used extensively in the management of patients with cancer of the esophagus. It has demonstrated an ability to cure a small minority of patients. Cure is likely to be limited to patients who have lesions less than 5 cm in length and have minimal, if any, involvement of lymph nodes. Esophagectomy is likely to cure a similar, small percentage of patients with the same presentation of minimal disease but has a substantial acute postoperative mortality rate and greater morbidity than irradiation. Combining surgery and either preoperative or postoperative irradiation may cure a small percentage of patients beyond the number cured with either modality alone. Radiation has demonstrated benefit as an adjuvant to surgery following the resection of minimal disease. However, radiation alone has never been compared directly with surgery for the highly select, minimal lesions managed by surgery. Radiation provides good palliation of dysphagia in the majority of patients, and roughly one third may have adequate swallowing for the duration of their illness when ''radical'' doses have been employed. Surgical bypass procedures have greater acute morbidity but appear to provide more reliable, prolonged palliation of dysphagia. Several approaches to improving the efficacy of irradiation are currently under investigation. These approahces include fractionation schedules, radiosensitizers, neutron-beam therapy, and helium-ion therapy.

  9. Radiation Therapy and Hearing Loss

    SciTech Connect

    Bhandare, Niranjan; Jackson, Andrew; Eisbruch, Avraham; Pan, Charlie C.; Flickinger, John C.; Antonelli, Patrick; Mendenhall, William M.

    2010-03-01

    A review of literature on the development of sensorineural hearing loss after high-dose radiation therapy for head-and-neck tumors and stereotactic radiosurgery or fractionated stereotactic radiotherapy for the treatment of vestibular schwannoma is presented. Because of the small volume of the cochlea a dose-volume analysis is not feasible. Instead, the current literature on the effect of the mean dose received by the cochlea and other treatment- and patient-related factors on outcome are evaluated. Based on the data, a specific threshold dose to cochlea for sensorineural hearing loss cannot be determined; therefore, dose-prescription limits are suggested. A standard for evaluating radiation therapy-associated ototoxicity as well as a detailed approach for scoring toxicity is presented.

  10. Radiation therapy of gynecological cancer

    SciTech Connect

    Nori, D.; Hilaris, B.S.

    1987-01-01

    This book consists of three parts: General Principles; Clinical Applications; and Special Topics. Some of the papers are: Introduction to Basic Radiobiology; Staging and Work-up Procedures for Patients with Gynecological Cancers; Radiation Therapy in the Treatment of Cancer of the Cervix; Role of Interstitial Implantation in Gynecological Cancer; Role of Radiocolloids in Gynecological Cancer; Radiosensitizers and Protectors; and Management of Lymphoma Associated with Pregnancy.

  11. Effectiveness of Biologic and Conventional Systemic Therapies in Adults with Chronic Plaque Psoriasis in Daily Practice: A Systematic Review.

    PubMed

    Zweegers, Jeffrey; Otero, Marisol E; van den Reek, Juul M P A; van Lümig, Paula P; Driessen, Rieke J; Kievit, Wietske; Seyger, Marieke M B; van de Kerkhof, Peter C M; de Jong, Elke M G J

    2016-04-12

    The efficacy of biologic or conventional systemic therapies for psoriasis has been shown in randomized controlled trials. Effectiveness, however, has been studied in daily practice cohorts, and no aggregation of effectiveness data is available. This systematic review searched PubMed and EMBASE and summarized the real-world evidence on effectiveness of biologics (adalimumab, etanercept, infliximab and ustekinumab) and conventional systemic therapies (acitretin, cyclosporine, fumarates and methotrexate) for the treatment of plaque psoriasis in adults. Thirty-two studies were included. Few data were available on infliximab, ustekinumab and conventional systemics. Results show that biologics and conventional systemics were effective in real-life treatment of psoriasis, with large ranges in the percentage of patients reaching 75% improvement in psoriasis area and severity index score compared with baseline, especially for etanercept and adalimumab treatment. Combination therapies of biologics with conventional systemics, and dose adjustments of biologics were frequently applied strategies and may explain the large range in improvements between cohorts. PMID:26537336

  12. Non-invasive in vivo characterization of human carotid plaques with acoustic radiation force impulse ultrasound: comparison with histology after endarterectomy.

    PubMed

    Czernuszewicz, Tomasz J; Homeister, Jonathon W; Caughey, Melissa C; Farber, Mark A; Fulton, Joseph J; Ford, Peter F; Marston, William A; Vallabhaneni, Raghuveer; Nichols, Timothy C; Gallippi, Caterina M

    2015-03-01

    Ischemic stroke from thromboembolic sources is linked to carotid artery atherosclerotic disease with a trend toward medical management in asymptomatic patients. Extent of disease is currently diagnosed by non-invasive imaging techniques that measure luminal stenosis, but it has been suggested that a better biomarker for determining risk of future thromboembolic events is plaque morphology and composition. Specifically, plaques that are composed of mechanically soft lipid/necrotic regions covered by thin fibrous caps are the most vulnerable to rupture. An ultrasound technique that non-invasively interrogates the mechanical properties of soft tissue, called acoustic radiation force impulse (ARFI) imaging, has been developed as a new modality for atherosclerotic plaque characterization using phantoms and atherosclerotic pigs, but the technique has yet to be validated in vivo in humans. In this preliminary study, in vivo ARFI imaging is presented in a case study format for four patients undergoing clinically indicated carotid endarterectomy and compared with histology. In two type Va plaques, characterized by lipid/necrotic cores covered by fibrous caps, mean ARFI displacements in focal regions were high relative to the surrounding plaque material, suggesting soft features were covered by stiffer layers within the plaques. In two type Vb plaques, characterized by heavy calcification, mean ARFI peak displacements were low relative to the surrounding plaque and arterial wall, suggesting stiff tissue. This pilot study illustrates the feasibility and challenges of transcutaneous ARFI for characterizing the material and structural composition of carotid atherosclerotic plaques via mechanical properties, in humans, in vivo. PMID:25619778

  13. Radiation therapy for brain tumors

    SciTech Connect

    Wara, W.M.

    1985-05-01

    Results of radiation therapy obtained at the University of California, San Francisco over the last 25 years for various adult types of brain tumors are presented. Included are astrocytomas, ependymomas, pineal and suprasellar tumors, meningiomas, and malignant gliomas. For each tumor type considered, the disease-free survival rate appeared to be improved when subtotal resection was followed by irradiation. The lack of improvement in survival with malignant gliomas has prompted investigation into more aggressive multimodality therapies. These are discussed along with a new program using high-activity iodine 125 sources to deliver high-dose radiotherapy to malignant gliomas. It is possible that this new approach will lead to improved survival rates and be applicable to many tumors within the central nervous system.

  14. Insufficiency fracture after radiation therapy

    PubMed Central

    Oh, Dongryul

    2014-01-01

    Insufficiency fracture occurs when normal or physiological stress applied to weakened bone with demineralization and decreased elastic resistance. Recently, many studies reported the development of IF after radiation therapy (RT) in gynecological cancer, prostate cancer, anal cancer and rectal cancer. The RT-induced insufficiency fracture is a common complication during the follow-up using modern imaging studies. The clinical suspicion and knowledge the characteristic imaging patterns of insufficiency fracture is essential to differentiate it from metastatic bone lesions, because it sometimes cause severe pain, and it may be confused with bone metastasis. PMID:25568849

  15. Antivascular Endothelial Growth Factor Bevacizumab for Radiation Optic Neuropathy: Secondary to Plaque Radiotherapy

    SciTech Connect

    Finger, Paul T.; Chin, Kimberly J.

    2012-02-01

    Purpose: To evaluate the intravitreal antivascular endothelial growth factor, bevacizumab, for treatment of radiation optic neuropathy (RON). Methods and Materials: A prospective interventional clinical case series was performed of 14 patients with RON related to plaque radiotherapy for choroidal melanoma. The RON was characterized by optic disc edema, hemorrhages, microangiopathy, and neovascularization. The entry criteria included a subjective or objective loss of vision, coupled with findings of RON. The study subjects received a minimum of two initial injections of intravitreal bevacizumab (1.25 mg in 0.05 mL) every 6-8 weeks. The primary objectives included safety and tolerability. The secondary objectives included the efficacy as measured using the Early Treatment Diabetic Retinopathy Study chart for visual acuity, fundus photography, angiography, and optical coherence tomography/scanning laser ophthalmoscopy. Results: Reductions in optic disc hemorrhage and edema were noted in all patients. The visual acuity was stable or improved in 9 (64%) of the 14 patients. Of the 5 patients who had lost vision, 2 had relatively large posterior tumors, 1 had had the vision decrease because of intraocular hemorrhage, and 1 had developed optic atrophy. The fifth patient who lost vision was noncompliant. No treatment-related ocular or systemic side effects were observed. Conclusions: Intravitreal antivascular endothelial growth factor bevacizumab was tolerated and generally associated with improved vision, reduced papillary hemorrhage, and resolution of optic disc edema. Persistent optic disc neovascularization and fluorescein angiographic leakage were invariably noted. The results of the present study support additional evaluation of antivascular endothelial growth factor medications as treatment of RON.

  16. Microbeam radiation therapy: Clinical perspectives.

    PubMed

    Grotzer, M A; Schültke, E; Bräuer-Krisch, E; Laissue, J A

    2015-09-01

    Microbeam radiation therapy (MRT), a novel form of spatially fractionated radiotherapy (RT), uses arrays of synchrotron-generated X-ray microbeams (MB). MRT has been identified as a promising treatment concept that might be applied to patients with malignant central nervous system (CNS) tumours for whom, at the current stage of development, no satisfactory therapy is available yet. Preclinical experimental studies have shown that the CNS of healthy rodents and piglets can tolerate much higher radiation doses delivered by spatially separated MBs than those delivered by a single, uninterrupted, macroscopically wide beam. High-dose, high-precision radiotherapies such as MRT with reduced probabilities of normal tissue complications offer prospects of improved therapeutic ratios, as extensively demonstrated by results of experiments published by many international groups in the last two decades. The significance of developing MRT as a new RT approach cannot be understated. Up to 50% of cancer patients receive conventional RT, and any new treatment that provides better tumour control whilst preserving healthy tissue is likely to significantly improve patient outcomes. PMID:25773883

  17. Missed Radiation Therapy and Cancer Recurrence

    Cancer.gov

    Patients who miss radiation therapy sessions during cancer treatment have an increased risk of their disease returning, even if they eventually complete their course of radiation treatment, according to a new study.

  18. Plaque regression and plaque stabilisation in cardiovascular diseases

    PubMed Central

    Dave, Tarun; Ezhilan, J.; Vasnawala, Hardik; Somani, Vinod

    2013-01-01

    Atherosclerosis is characterized by formation of plaques on the inner walls of arteries that threatens to become the leading cause of death worldwide via its sequelae of myocardial infarction and stroke. Endothelial dysfunction leads to cholesterol uptake and accumulation of inflammatory markers within the plaque. The stability of a plaque eventually depends on the balance between vascular smooth muscle cells that stabilize it and the inflammatory cells like macrophages and T lymphocytes that make it prone to rupture. The current approach to manage atherosclerosis focuses on the treatment of a ruptured plaque and efforts have been made to reduce the risk of plaque rupture by identifying vulnerable plaques and treating them before they precipitate into clinical events. New diagnostic approaches such as IVUS and CIMT ultrasound are now being preferred over traditional coronary angiography because of their better accuracy in measuring plaque volume rather than the level of stenosis caused. The present review highlights the literature available on two prevalent approaches to manage a vulnerable plaque, namely, plaque stabilization and plaque regression, and their validation through various treatment modalities in recent plaque management studies. Plaque stabilization focuses on stabilizing the content of plaque and strengthening the overlying endothelium, while plaque regression focuses on the overall reduction in plaque volume and to reverse the arterial endothelium to its normal functional state. Although earlier studies contemplated the practicality of plaque regression and focused greatly on stabilization of a vulnerable plaque, our review indicated that, aided by the use of superior diagnostics tools, more intensive lipid modifying therapies have resulted in actual plaque regression. PMID:24381872

  19. Effects of Statin Therapy on Coronary Artery Plaque Volume and High Risk Plaque Morphology in HIV-Infected Patients with Subclinical Atherosclerosis: a Randomized Double-Blind Placebo-Controlled Trial

    PubMed Central

    Lo, Janet; Lu, Michael T.; Ihenachor, Ezinne J.; Wei, Jeffrey; Looby, Sara E.; Fitch, Kathleen V.; Oh, Jinhee; Zimmerman, Chloe O.; Hwang, Janice; Abbara, Suhny; Plutzky, Jorge; Robbins, Gregory; Tawakol, Ahmed; Hoffmann, Udo; Grinspoon, Steven K.

    2016-01-01

    Background No studies have yet assessed the ability of statin treatment to reduce arterial inflammation and achieve regression of coronary atherosclerosis in HIV-infected patients, a population with elevated risk of myocardial infarction. Methods In a randomized, double-blind, placebo-controlled trial, 40 HIV-infected participants with subclinical coronary atherosclerosis, evidence of arterial inflammation in the aorta by fluorodeoxyglucose positron emission tomography (FDG-PET) and low density lipoprotein(LDL)-cholesterol <3·37mmol/L(130mg/dL) were randomized to one year of treatment with atorvastatin (n=19) or placebo (n=21). Randomization was carried out by the MGH Clinical Research Pharmacy using a permuted-block algorithm, stratified by gender with a fixed block size of four, with 1:1 allocation to atorvastatin or identical matching placebo. Study codes were available only to the MGH Research Pharmacy and not to study investigators or participants. The prespecified primary endpoint was arterial inflammation, as assessed by FDG-PET of the aorta. Additional prespecified endpoints included coronary atherosclerotic plaque as assessed by coronary computed tomography angiography. We quantitatively assessed non-calcified and calcified plaque and high risk plaque features. Analysis was performed using intention-to-treat principle, using all available data, without imputation for missing data. Findings Thirty seven out of forty (92·5%) subjects completed the study, with equivalent discontinuation rates in both groups. Baseline parameters were similar between groups. After 12 months, change in FDG-PET uptake of the most diseased segment of the aorta was not different between atorvastatin and placebo, but technically adequate results comparing longitudinal changes in identical regions could only be assessed in a subset of patients (atorvastatin Δ −0·03 [95% CI: −0·17, 0·12] vs. placebo Δ −0·06 [−0·25, 0·13], p=0·77, n=21). Change in plaque could be assessed in all subjects completing the study. Atorvastatin reduced noncalcified coronary plaque volume compared to placebo (−19·4%(IQR: −39·2%, 9·3%) vs. +20·4%(−7·1%, 94·4%), p=0·009, n=37). In addition, the number of high risk plaques was significantly reduced by atorvastatin compared to placebo (change in number of low attenuation plaques −0·2[95% CI: −0·6, 0·2] vs. 0·4[0·0, 0·7], p=0·03, n=37 and change in number of positively remodeled plaques −0·2[95% CI −0·4, 0·1] vs. 0·4[−0·1, 0·8], p=0·04, n=37). Direct LDL-cholesterol (−1·00[95% CI −1·38, 0·61] vs. 0·30[0·04, 0·55] mmol/L, p<0·0001) and lipoprotein-associated phospholipase A2 (−52·2[95% CI −70·4, −34·0] vs. −13·3[−32·8, 6·2] ng/mL, p=0·005, n=37) significantly decreased with atorvastatin compared to placebo. Statin therapy was well-tolerated, with low incidence of clinical adverse events. Interpretation Compared to placebo, statin therapy reduces noncalcified plaque volume and high risk plaque features in HIV-infected patients with subclinical coronary atherosclerosis. Significant effects of statin therapy on arterial inflammation of the aorta by FDG-PET were not seen. Further studies should assess whether reduction in high risk coronary artery disease translates into effective prevention of cardiovascular events in this at risk population. PMID:26424461

  20. Melioidosis: reactivation during radiation therapy

    SciTech Connect

    Jegasothy, B.V.; Goslen, J.B.; Salvatore, M.A.

    1980-05-01

    Melioidosis is caused by Pseudomonas pseudomallei, a gram-negative, motile bacillus which is a naturally occurring soil saprophyte. The organism is endemic in Southeast Asia, the Philippines, Australia, and parts of Central and South America. Most human disease occurs from infection acquired in these countries. Infection with P pseudomallei may produce no apparent clinical disease. Acute pneumonitis or septicemia may result from inhalation of the organism, and inoculation into sites of trauma may cause localized skin abscesses, or the disease may remain latent and be reactivated months or years later by trauma, burns, or pneumococcal pneumonia, diabetic ketoacidosis, influenza, or bronchogenic carcinoma. The last is probably the commonest form of melioidosis seen in the United States. We present the first case of reactivation of melioidosis after radiation therapy for carcinoma of the lung, again emphasizing the need to consider melioidosis in a septic patient with a history of travel, especially to Southeast Asia.

  1. Radiation therapy for oral cavity cancer.

    PubMed

    Harrison, L B; Fass, D E

    1990-04-01

    Radiation therapy, using both external beam and brachytherapy, is one of the mainstays of treatment for oral cavity cancers. For early lip, tongue, and floor of mouth lesions, radiation alone is highly effective and produces an excellent functional result. More advanced lesions are frequently treated with combined therapy or radiation alone with surgical salvage. Buccal mucosa and gingiva lesions are generally treated with surgery but can be managed by radiation therapy if they are early. More advanced lesions are treated by surgery plus postoperative radiation. Retromolar trigone lesions can be managed by radiation alone if they are small, but larger lesions are generally treated by combined therapy. Clearly, the goal of treatment of squamous cell cancer of the oral cavity is cure of the disease with optimal function results. These goals can be achieved only by cooperative interdisciplinary evaluation and management by the surgeons, radiation oncologists, and dentists involved in the care of these patients. PMID:2186932

  2. Vulnerable Plaque

    MedlinePlus

    ... plaque. Can vulnerable plaque be prevented? Patients can lower their C-reactive protein levels in the same ... lowering medicines called statins have been found to lower C-reactive protein levels, and doctors are now ...

  3. Acoustic Radiation Force Beam Sequence Performance for Detection and Material Characterization of Atherosclerotic Plaques: Preclinical, Ex Vivo Results

    PubMed Central

    Behler, Russell H.; Czernuszewicz, Tomasz J.; Wu, Chih-Da; Nichols, Timothy C.; Zhu, Hongtu; Homeister, Jonathon W.; Merricks, Elizabeth P.; Caughey, Melissa C.; Gallippi, Caterina M.

    2014-01-01

    This work presents preclinical data demonstrating performance of acoustic radiation force (ARF) based elasticity imaging with five different beam sequences for atherosclerotic plaque detection and material characterization. Twelve trained, blinded readers evaluated parametric images taken ex vivo under simulated in vivo conditions of 22 porcine femoral arterial segments. Receiver operating characteristic (ROC) curve analysis was carried out to quantify reader performance using spatially-matched immunohistochemistry for validation. The beam sequences employed had high sensitivity and specificity for detecting Type III+ plaques (Sens: 85%, Spec: 79%), lipid pools (Sens: 80%, Spec: 86%), fibrous caps (Sens: 86%, spec: 82%), calcium (Sens: 96%, Spec: 85%), collagen (Sens: 78%, Spec: 77%), and disrupted internal elastic lamina (Sens: 92%, Spec: 75%). 1:1 single-receive tracking yielded the highest median areas under the ROC curve (AUC), but was not statistically significantly higher than 4:1 parallel-receive tracking. Excitation focal configuration did not result in statistically different AUCs. Overall, these results suggest ARF-based imaging is relevant to detecting and characterizing plaques and support its use for diagnosing and monitoring atherosclerosis. PMID:24297014

  4. Radiation therapy facilities in the United States

    SciTech Connect

    Ballas, Leslie K.; Elkin, Elena B. . E-mail: elkine@mskcc.org; Schrag, Deborah; Minsky, Bruce D.; Bach, Peter B.

    2006-11-15

    Purpose: About half of all cancer patients in the United States receive radiation therapy as a part of their cancer treatment. Little is known, however, about the facilities that currently deliver external beam radiation. Our goal was to construct a comprehensive database of all radiation therapy facilities in the United States that can be used for future health services research in radiation oncology. Methods and Materials: From each state's health department we obtained a list of all facilities that have a linear accelerator or provide radiation therapy. We merged these state lists with information from the American Hospital Association (AHA), as well as 2 organizations that audit the accuracy of radiation machines: the Radiologic Physics Center (RPC) and Radiation Dosimetry Services (RDS). The comprehensive database included all unique facilities listed in 1 or more of the 4 sources. Results: We identified 2,246 radiation therapy facilities operating in the United States as of 2004-2005. Of these, 448 (20%) facilities were identified through state health department records alone and were not listed in any other data source. Conclusions: Determining the location of the 2,246 radiation facilities in the United States is a first step in providing important information to radiation oncologists and policymakers concerned with access to radiation therapy services, the distribution of health care resources, and the quality of cancer care.

  5. Radiation therapy among A-bomb survivors.

    PubMed Central

    Russell, W J; Antoku, S

    1976-01-01

    Survey of hospitals and clinics where atomic bomb survivors and their comparisons reported having received radiation therapy confirmed that 137 were so treated. The malignancies of five subjects were possibly related to their earlier radiation therapy rather than their atomic bomb radiation exposure, stressing the importance of recording all medical X-ray exposures as a potential variable in epidemiological studies of cancer etiology. PMID:961946

  6. Neurogenic fibrosarcoma following radiation therapy for seminoma

    SciTech Connect

    O'Brien, W.M.; Abbondanzo, S.L.; Chun, B.K.; Manz, H.J.; Maxted, W.C.

    1989-05-01

    We report a case of radiation-induced neurogenic fibrosarcoma that developed in a patient who received radiation therapy for seminoma. The sarcoma developed within the irradiated field after a latency period of nineteen years. Although the occurrence of a secondary neoplasm is unusual, this possibility should be included in the differential diagnosis of patients who present with tumor growth after a long interval following radiation therapy.

  7. The role of radiation therapy in melanoma.

    PubMed

    Oxenberg, Jacqueline; Kane, John M

    2014-10-01

    Although melanoma was historically thought to be radiation resistant, there are limited data to support the use of adjuvant radiation therapy for certain situations at increased risk for locoregional recurrence. High-risk primary tumor features include thickness, ulceration, certain anatomic locations, satellitosis, desmoplastic/neurotropic features, and head and neck mucosal and anorectal melanoma. Lentigo maligna can be effectively treated with either adjuvant or definitive radiation therapy. Some retrospective and prospective randomized studies support the use of adjuvant radiation to improve regional control after lymph node dissection for high-risk nodal metastatic disease. Consensus on the optimal radiation doses and fractionation is lacking. PMID:25245966

  8. When the Synchrotron radiations highlight the Randall's plaques and kidney concretions

    NASA Astrophysics Data System (ADS)

    Daudon, M.; Bazin, D.

    2013-03-01

    In western countries, a dramatic increase in papilla calcifications (Randall's Plaque or RP) is observed as a major cause of calcium oxalate kidney stones. Through ex vivo X-ray absorption spectroscopy, we give for the first time direct structural evidence of the presence of amorphous carbonated calcium phosphate in these Randall's plaques (RP). Such chemical composition of RP present in increasingly young subjects raises a major question regarding alimentation: does nutrient-enriched food especially aimed at young children affect the physiology of the kidney? Moreover, lithogenic diseases may induce intratubular crystallization and end-stage renal failure. We show that Fourier transform infrared microspectroscopy is able to characterize such pathological microcalcifications giving their chemical composition and their spatial distribution, thus providing invaluable information for the diagnosis of the disease and the treatment of the patients.

  9. Radiation Therapy Physics, 3rd Edition

    NASA Astrophysics Data System (ADS)

    Hendee, William R.; Ibbott, Geoffrey S.; Hendee, Eric G.

    2004-08-01

    The Third Edition of Radiation Therapy Physics addresses in concise fashion the fundamental diagnostic radiologic physics principles as well as their clinical implications. Along with coverage of the concepts and applications for the radiation treatment of cancer patients, the authors have included reviews of the most up-to-date instrumentation and critical historical links. The text includes coverage of imaging in therapy planning and surveillance, calibration protocols, and precision radiation therapy, as well as discussion of relevant regulation and compliance activities. It contains an updated and expanded section on computer applications in radiation therapy and electron beam therapy, and features enhanced user-friendliness and visual appeal with a new, easy-to-follow format, including sidebars and a larger trim size. With its user-friendly presentation and broad, comprehensive coverage of radiotherapy physics, this Third Edition doubles as a medical text and handy professional reference.

  10. Intraoperative radiation therapy following pancreaticoduodenectomy.

    PubMed Central

    Evans, D B; Termuhlen, P M; Byrd, D R; Ames, F C; Ochran, T G; Rich, T A

    1993-01-01

    OBJECTIVE: To determine the morbidity and mortality of pancreaticoduodenectomy followed by electron-beam intraoperative radiation therapy (EB-IORT). SUMMARY BACKGROUND DATA: Local recurrence following pancreaticoduodenectomy occurs in 50% to 90% of patients who undergo a potentially curative surgical resection for adenocarcinoma of the pancreatic head. To improve local disease control, a more aggressive retroperitoneal dissection has been combined with adjuvant EB-IORT. METHODS: Forty-one patients with malignant neoplasms of the periampullary region underwent pancreaticoduodenectomy followed by EB-IORT between January 1989 and May 1992. EB-IORT was delivered in a dedicated operative suite, eliminating the need for patient relocation. Electron-beam energies of 6 to 12 MeV were used to deliver 10 to 20 Gy to the treatment field following resection but before pancreatic, biliary, and gastrointestinal reconstruction. RESULTS: Median operative time was 9 hours, blood loss was 1 L, perioperative transfusion requirement was 2 units, and hospital stay was 20 days. One patient died of a postoperative myocardial infarction, and four patients required reoperation, one for an anastomotic leak. No patient failed to receive EB-IORT because of operative complications during the time period of this study. CONCLUSION: Adjuvant EB-IORT after pancreaticoduodenectomy can be delivered safely, with low mortality and acceptable morbidity. Images Figure 1. Figure 1. PMID:8101073

  11. 42 CFR 410.35 - X-ray therapy and other radiation therapy services: Scope.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false X-ray therapy and other radiation therapy services... Other Health Services § 410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy...

  12. 42 CFR 410.35 - X-ray therapy and other radiation therapy services: Scope.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false X-ray therapy and other radiation therapy services... Other Health Services § 410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy...

  13. 42 CFR 410.35 - X-ray therapy and other radiation therapy services: Scope.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false X-ray therapy and other radiation therapy services... Other Health Services § 410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy...

  14. 42 CFR 410.35 - X-ray therapy and other radiation therapy services: Scope.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 2 2012-10-01 2012-10-01 false X-ray therapy and other radiation therapy services... Other Health Services § 410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy...

  15. 42 CFR 410.35 - X-ray therapy and other radiation therapy services: Scope.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 2 2013-10-01 2013-10-01 false X-ray therapy and other radiation therapy services... Other Health Services § 410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy...

  16. Radiation Sensitization in Cancer Therapy.

    ERIC Educational Resources Information Center

    Greenstock, Clive L.

    1981-01-01

    Discusses various aspects of radiation damage to biological material, including free radical mechanisms, radiation sensitization and protection, tumor hypoxia, mechanism of hypoxic cell radiosensitization, redox model for radiation modification, sensitizer probes of cellular radiation targets, pulse radiolysis studies of free radical kinetics,

  17. Radiation Sensitization in Cancer Therapy.

    ERIC Educational Resources Information Center

    Greenstock, Clive L.

    1981-01-01

    Discusses various aspects of radiation damage to biological material, including free radical mechanisms, radiation sensitization and protection, tumor hypoxia, mechanism of hypoxic cell radiosensitization, redox model for radiation modification, sensitizer probes of cellular radiation targets, pulse radiolysis studies of free radical kinetics,…

  18. Comparing Postoperative Radiation Therapies for Brain Metastases

    Cancer.gov

    In this clinical trial, patients with one to four brain metastases who have had at least one of the metastatic tumors removed surgically will be randomly assigned to undergo whole-brain radiation therapy or stereotactic radiosurgery.

  19. Migratory eosinophilic alveolitis caused by radiation therapy.

    PubMed

    Lim, Jun Hyeok; Nam, Hae-Seong; Kim, Hun Jung; Choi, Chang-Hwan; Park, In-Suh; Cho, Jae Hwa; Ryu, Jeong-Seon; Kwak, Seung Min; Lee, Hong Lyeol

    2015-05-01

    Although radiation pneumonitis is usually confined to irradiated areas, some studies have reported that radiation-induced lymphocytic alveolitis can also spread to the non-irradiated lung. However, there have been few reports of radiation-induced eosinophilic alveolitis. We report the case of a 27-year-old female with radiation pneumonitis, occurring 4 months after radiation therapy for cancer of the left breast. Clinical and radiological relapse followed withdrawal of corticosteroids. Examination of bronchoalveolar lavage (BAL) in patchy airspace consolidations revealed increased eosinophil counts. Finally, clinical and radiological signs resolved rapidly after reintroduction of corticosteroids. Eosinophilic alveolitis may be promoted by radiation therapy. In the present case report, possible mechanisms for radiation-induced eosinophilic alveolitis are also reviewed. PMID:26101656

  20. Nursing care update: Internal radiation therapy

    SciTech Connect

    Lowdermilk, D.L.

    1990-01-01

    Internal radiation therapy has been used in treating gynecological cancers for over 100 years. A variety of radioactive sources are currently used alone and in combination with other cancer treatments. Nurses need to be able to provide safe, comprehensive care to patients receiving internal radiation therapy while using precautions to keep the risks of exposure to a minimum. This article discusses current trends and issues related to such treatment for gynecological cancers.20 references.

  1. Particle Radiation Therapy: Requiem or Reveille

    PubMed Central

    Alexander, Leslie L.; Goldson, Alfred L.; Alexander, George A.

    1979-01-01

    The 1960s and 1970s witnessed a surge of many institutions devoted to electron therapy. Currently, many facilities are adding or have added particle types of radiation to their armamentarium against cancer. The authors review the concepts, problems, and potentials of this form of therapy. ImagesFigure 1 PMID:423289

  2. Radiologist, computed tomography, and radiation therapy

    SciTech Connect

    Goitein, M.; Meyer, J.

    1982-06-01

    The use of computed tomography (CT) in planning radiation therapy is discussed. The three major issues that involve collaboration between the diagnostic radiologist and the radiation therapist are identified as selection of equipment, logistics, and conduct of individual CT studies. The importance of cooperation between the diagnostic and therapeutic radiologist is stressed.

  3. How Should I Care for Myself During Radiation Therapy?

    MedlinePlus

    ... Upper GI What is Radiation Therapy? Find a Radiation Oncologist Last Name: Facility: City: State: Zip Code: ... information How Should I Care for Myself During Radiation Therapy? Get plenty of rest. Many patients experience ...

  4. Radiation Therapy and You: Support for People with Cancer

    MedlinePlus

    ... Terms Blogs and Newsletters Health Communications Publications Reports Radiation Therapy and You: Support for People With Cancer ... Copy This booklet covers: Questions and Answers About Radiation Therapy. Answers common questions, such as what radiation ...

  5. Impaired skin integrity related to radiation therapy

    SciTech Connect

    Ratliff, C.

    1990-09-01

    Skin reactions associated with radiation therapy require frequent nursing assessment and intervention. Preventive interventions and early management can minimize the severity of the skin reaction. With the understanding of the pathogenesis of radiation skin reactions, the ET nurse can determine who is at risk and then implement preventive measures. Because radiation treatment is fractionated, skin reactions do not usually occur until midway through the course of therapy and will subside within a few weeks after completion of radiation. Many patients and their families still fear that radiation causes severe burns. Teaching and anticipatory guidance by the ET nurse is needed to assist patients and their families to overcome this fear, and to educate them on preventive skin care regimens.

  6. Antimicrobial Photodynamic Therapy and Dental Plaque: A Systematic Review of the Literature

    PubMed Central

    Santin, G. C.; Oliveira, D. S. B.; Galo, R.; Borsatto, M. C.; Corona, S. A. M.

    2014-01-01

    Background. The aim of this study was to perform a systematic review of the literature on the efficacy of antimicrobial photodynamic therapy (PDTa) on cariogenic dental biofilm. Types of Studies Reviewed. Studies in vivo, in vitro, and in situ were included. Articles that did not address PDTa, those that did not involve cariogenic biofilm, those that used microorganisms in the plankton phase, and reviews were excluded. Data extraction and quality assessments were performed independently by two raters using a scale. Results. Two hundred forty articles were retrieved; only seventeen of them met the eligibility criteria and were analyzed in the present review. Considerable variability was found regarding the methodologies and application protocols for antimicrobial PDTa. Two articles reported unfavorable results. Practical Implications. The present systematic review does not allow drawing any concrete conclusions regarding the efficacy of antimicrobial PDTa, although this method seems to be a promising option. PMID:25379545

  7. Resource Letter MPRT-1: Medical Physics in Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Ratliff, Steven T.

    2009-09-01

    This resource letter provides a guide to the literature on medical physics in the field of radiation therapy. Journal articles, books, and websites are cited for the following topics: radiological physics, particle accelerators, radiation dose measurements, protocols for radiation dose measurements, radiation shielding and radiation protection, neutron, proton, and heavy-ion therapies, imaging for radiation therapy, brachytherapy, quality assurance, treatment planning, dose calculations, and intensity-modulated and image-guided therapy.

  8. Film dosimetry analyses on the effect of gold shielding for Iodine-125 eye plaque therapy for choroidal melanoma

    SciTech Connect

    Wu, A. ); Krasin, F. )

    1990-09-01

    One of the methods currently being used to treat choroidal melanoma employs an episcleral plaque containing I-125 radioactive seeds. However, comprehensive dosimetry studies on the plaque are scarce and controversial. For this work, we use film to study the dosimetry outside the lip of the gold shield of the eye plaque. This lip around the gold shield was made to protect the critical structures behind and adjacent to the lesion. Since the changes of energy spectrum of I-125 in tissue are negligible, film dosimetry seems to be a logical choice because of high spatial resolution required around the lip of the gold plaque. For this study, we first established an H and D curve with dose expressed in a unit of specific dose rate constant. This avoids absolute dose measurements. All film density measurements are made with a 1-mm aperture scan, normalized to the density at the prescription point for tumor of 3--5-mm apical height, i.e., 5 mm from the interior surface of sclera, and converted to percentage isodose curves. With a gold shield, it is found that when the plaque is placed against the optical nerve, the optical disk and macula, located at 2 mm outside the lip, on the exterior surface of sclera, may receive 85% of the prescription dose for a 12-mm plaque and 58% for a 16-mm plaque. For tumors of 8-mm apical height, the optical nerve would receive more than the prescription dose.

  9. Film dosimetry analyses on the effect of gold shielding for iodine-125 eye plaque therapy for choroidal melanoma.

    PubMed

    Wu, A; Krasin, F

    1990-01-01

    One of the methods currently being used to treat choroidal melanoma employs an episcleral plaque containing I-125 radioactive seeds. However, comprehensive dosimetry studies on the plaque are scarce and controversial. For this work, we use film to study the dosimetry outside the lip of the gold shield of the eye plaque. This lip around the gold shield was made to protect the critical structures behind and adjacent to the lesion. Since the changes of energy spectrum of I-125 in tissue are negligible, film dosimetry seems to be a logical choice because of high spatial resolution required around the lip of the gold plaque. For this study, we first established an H and D curve with dose expressed in a unit of specific dose rate constant. This avoids absolute dose measurements. All film density measurements are made with a 1-mm aperture scan, normalized to the density at the prescription point for tumor of 3-5-mm apical height, i.e., 5 mm from the interior surface of sclera, and converted to percentage isodose curves. With a gold shield, it is found that when the plaque is placed against the optical nerve, the optical disk and macula, located at 2 mm outside the lip, on the exterior surface of sclera, may receive 85% of the prescription dose for a 12-mm plaque and 58% for a 16-mm plaque. For tumors of 8-mm apical height, the optical nerve would receive more than the prescription dose. PMID:2233570

  10. Ocular neuromyotonia after radiation therapy

    SciTech Connect

    Lessell, S.; Lessell, I.M.; Rizzo, J.F. III

    1986-12-15

    Ocular neuromyotonia is a paroxysmal monocular deviation that results from spasm of eye muscles secondary to spontaneous discharges from third, fourth, or sixth nerve axons. We observed this rare disorder in four patients who had been treated with radiation for tumors in the region of the sella turcica and cavernous sinus. Based on these cases and four others identified in the literature it would appear that radiation predisposes to a cranial neuropathy in which ocular neuromyotonia may be the major manifestation. Radiation appears to be the most common cause of ocular neuromyotonia.

  11. Radiation Therapy for Breast Cancer

    MedlinePlus

    ... is done with high energy X-rays, or photons, for the bulk of the treatment. When there ... a less penetrating, more focused beam instead of photons. Different techniques can be used to give radiation ...

  12. Anesthesia for intraoperative radiation therapy in children

    SciTech Connect

    Friesen, R.H.; Morrison, J.E. Jr.; Verbrugge, J.J.; Daniel, W.E.; Aarestad, N.O.; Burrington, J.D.

    1987-06-01

    Intraoperative radiation therapy (IORT) is a relatively new mode of cancer treatment which is being used with increasing frequency. IORT presents several challenges to the anesthesiologist, including patients who are debilitated from their disease or chemotherapy, operations involving major tumor resections, intraoperative interdepartmental transport of patients, and remote monitoring of patients during electron beam therapy. This report discusses the anesthetic management of ten children undergoing IORT. With adequate preparation and interdepartmental communication, complications can be avoided during these challenging cases.

  13. Early cardiac changes related to radiation therapy

    SciTech Connect

    Ikaeheimo, M.J.N.; Niemelae, K.O.L.; Linnaluoto, M.M.; Jakobsson, M.J.; Takkunen, J.T.; Taskinen, P.J.

    1985-12-01

    To investigate the incidence and severity of possible radiation-induced cardiac changes, 21 women without heart disease were investigated serially by echocardiography and by measuring systolic time intervals before and up to 6 months after postoperative radiation therapy because of breast cancer. Radiation was associated with a decrease in fractional systolic shortening of the left ventricular (LV) minor-axis diameter, from 0.35 +/- 0.05 to 0.32 +/- 0.06 (p less than 0.005), and in the systolic blood pressure/end-systolic diameter ratio, from 4.4 +/- 1.2 to 3.9 +/- 0.9 mm Hg/mm (p less than 0.005). The mitral E point-septal separation increased, from 2.8 +/- 1.5 to 4.2 +/- 2.5 mm (p less than 0.005). The preejection period/LV ejection time ratio of systolic time intervals increased, but only the decrease within 6 months after therapy was significant (p less than 0.005). All these changes reflect slight transient depression of LV function, which became normalized within 6 months after therapy. Up to 6 months after therapy, a slight pericardial effusion was found in 33% of the patients. Hence, conventional radiation therapy appeared to cause an acute transient and usually symptomless decrease in LV function, and later, slight pericardial effusion in one-third of the patients.

  14. Respiratory Motion Prediction in Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Vedam, Sastry

    Active respiratory motion management has received increasing attention in the past decade as a means to reduce the internal margin (IM) component of the clinical target volume (CTV)—planning target volume (PTV) margin typically added around the gross tumor volume (GTV) during radiation therapy of thoracic and abdominal tumors. Engineering and technical developments in linear accelerator design and respiratory motion monitoring respectively have made the delivery of motion adaptive radiation therapy possible through real-time control of either dynamic multileaf collimator (MLC) motion (gantry based linear accelerator design) or robotic arm motion (robotic arm mounted linear accelerator design).

  15. Bullous pemphigoid after radiation therapy

    SciTech Connect

    Duschet, P.; Schwarz, T.; Gschnait, F.

    1988-02-01

    Electron beam therapy applied to a lymph node metastasis from a squamous cell carcinoma was followed by the development of histologically and immunologically typical bullous pemphigoid, the lesions being initially strictly confined to the irradiation area. This observation suggests that the bullous pemphigoid antigen may be altered or unmasked by electron beam radiotherapy, leading subsequently to the production of autoantibodies. The disease in this case effectively responded to the administration of tetracycline and niacinamide, a therapeutic regimen described recently.

  16. Effects of radiation therapy in microvascular anastomoses

    SciTech Connect

    Fried, M.P.

    1985-07-01

    The otolaryngologist, as a head and neck surgeon, commonly cares for patients with upper aerodigestive tract malignancies. Therapy of these neoplasms often requires wide excision. One standard reconstructive procedure utilizes pedicled regional flaps, both dermal and myodermal which have some disadvantages. The shortcomings of these pedicled regional flaps have led to the use of the vascularized free flap in certain cases. The occasional case may lead to catastrophe if microanastomoses fail when combined with radiation. Notwithstanding, many surgical series have reported success when radiation has been given. The present investigation was undertaken to assess the effects of radiation therapy on microvascular anastomoses when radiation is administered pre- or postoperatively or when nonradiated tissue is transferred to an irradiated recipient site. These effects were observed serially in an experimental rat model using a tubed superficial epigastric flap that adequately reflected tissue viability and vascular patency. The histologic changes were then noted over a three month period after completion of both radiation and surgery. This study adds credence to the observation of the lack of deleterious effects of radiation on experimental microvascular anastomotic patency whether the radiation is given before or after surgery or if radiated tissue is approximated to nonradiated vessels.

  17. Secondary Malignancy Risk Following Proton Radiation Therapy

    PubMed Central

    Eaton, Bree R.; MacDonald, Shannon M.; Yock, Torunn I.; Tarbell, Nancy J.

    2015-01-01

    Radiation-induced secondary malignancies are a significant, yet uncommon cause of morbidity and mortality among cancer survivors. Secondary malignancy risk is dependent upon multiple factors including patient age, the biological and genetic predisposition of the individual, the volume and location of tissue irradiated, and the dose of radiation received. Proton therapy (PRT) is an advanced particle therapy with unique dosimetric properties resulting in reduced entrance dose and minimal to no exit dose when compared with standard photon radiation therapy. Multiple dosimetric studies in varying cancer subtypes have demonstrated that PRT enables the delivery of adequate target volume coverage with reduced integral dose delivered to surrounding tissues, and modeling studies taking into account dosimetry and radiation cell biology have estimated a significantly reduced risk of radiation-induced secondary malignancy with PRT. Clinical data are emerging supporting the lower incidence of secondary malignancies after PRT compared with historical photon data, though longer follow-up in proton treated cohorts is awaited. This article reviews the current dosimetric and clinical literature evaluating the incidence of and risk factors associated with radiation-induced secondary malignancy following PRT. PMID:26636040

  18. World radiation therapy dosimetry network.

    PubMed

    Lanzl, L H

    1982-09-01

    The ultimate responsibility for the standardization of radiation exposures and doses within a country lies with the country's national standardizing laboratory, provided that the country has such a laboratory. In the late 1960's, only 17 countries had primary national standards laboratories, whereas more than 100 countries did not. Therefore, the International Atomic Energy Agency undertook a program of developing a network of secondary standards dosimetry laboratories (SSDL) and was later joined in the project by the World Health Organization. By 1982, the network consisted of SSDL's in 35 countries. The United States has three secondary or regional dosimetry laboratories for instrument calibration traceable to the U.S. National Bureau of Standards. Studies of radiation responses of biological systems, including normal and tumor tissue, provide information on the accuracy of dose measurements required for assessment of these responses. PMID:7141936

  19. Cobalt60 plaques in recurrent retinoblastoma

    SciTech Connect

    Fass, D.; McCormick, B.; Abramson, D.; Ellsworth, R. )

    1991-08-01

    Cobalt60 plaque irradiation is one treatment option for patients with recurrent retinoblastoma following conventional external beam irradiation (ERT). Tumorocidal doses can be delivered without excessive risk of normal tissue injury. In patients not considered candidates for xenon arc or cryotherapy, 60Co is an alternative to enucleation. Between 1968 and 1987, 85 patients were treated with 60Co plaques, 72 of whom had failed prior ERT. Age at diagnosis ranged from 1 week to 4 years. There are 37 males and 35 females. Seventy-one patients had bilateral disease and one had unilateral. Three patients had both eyes plaqued. Prior ERT ranged from 30 to 70 Gy (mean 4200 Gy). Time from initial therapy to failure ranged from 13 to 60 months. Cobalt plaques of 10 mm, 15 mm, or 10 {times} 15 mm were used depending on tumor size and location. Dose prescribed to the apex of the tumor ranged from 30 to 50 Gy (median 40 Gy) given over 3 to 8 days. Twelve patients had two plaque applications; three patients had three plaque applications. All patients were followed with routine ophthalmoscopic examinations. Follow-up ranged from 2 to 22 years (mean 8.7). Seven patients died of metastatic disease; 10 patients developed non-ocular second tumors. Thirty patients required enucleation. Twenty-two patients had clear tumor progression, two patients had radiation complications, and six patients had a combination of tumor growth and complications. Cobalt60 can salvage eyes in retinoblastoma patients failing ERT. Currently, the authors are using I125 in an attempt to spare normal ocular tissue and reduce subsequent complications.

  20. Radiation therapy communication: equine hemangioma.

    PubMed

    Kleiter, Miriam; Velde, Karsten; Hainisch, Edmund; Auer, Ulrike; Reifinger, Martin

    2009-01-01

    A 13-month-old Standardbred Colt had a recurrent hemangioma at the level of the coronary band. Multiple excisions had led to a nonhealing skin and hoof defect. Using 14 MV electrons, a total dose of 36 Gy was administered, given as six fractions of 6 Gy twice a week. Wound healing by second intention was achieved over the next 4 months and the colt began race training 6 months after the end of therapy. Twenty months later the colt is sound and there is no evidence of tumor recurrence. PMID:19788045

  1. Glossodynia after radiation therapy and chemotherapy

    SciTech Connect

    Naylor, G.D.; Marino, G.G.; Shumway, R.C.

    1989-10-01

    Radiation therapy and chemotherapy have decreased the mortality rates of cancer patients, but the morbidity associated with oral complications is high in many cases. A pretreatment oral evaluation and institution of a preventive care program reduce oral symptoms such as glossodynia considerably. When oral symptoms are minimized, the dentist can improve the patient's quality of life.40 references.

  2. Process of Coping with Radiation Therapy.

    ERIC Educational Resources Information Center

    Johnson, Jean E.; And Others

    1989-01-01

    Evaluated ability of self-regulation and emotional-drive theories to explain effects of informational intervention entailing objective descriptions of experience on outcomes of coping with radiation therapy among 84 men with prostate cancer. Consistent with self-regulation theory, similarity between expectations and experience and degree of

  3. Process of Coping with Radiation Therapy.

    ERIC Educational Resources Information Center

    Johnson, Jean E.; And Others

    1989-01-01

    Evaluated ability of self-regulation and emotional-drive theories to explain effects of informational intervention entailing objective descriptions of experience on outcomes of coping with radiation therapy among 84 men with prostate cancer. Consistent with self-regulation theory, similarity between expectations and experience and degree of…

  4. Radiation therapy for orbital lymphoma

    SciTech Connect

    Zhou Ping . E-mail: pzhou@partners.org; Ng, Andrea K.; Silver, Barbara; Li Sigui; Hua Ling; Mauch, Peter M.

    2005-11-01

    Purpose: To describe radiation techniques and evaluate outcomes for orbital lymphoma. Methods and Materials: Forty-six patients (and 62 eyes) with orbital lymphoma treated with radiotherapy between 1987 and 2003 were included. The majority had mucosa-associated lymphoid tissue (48%) or follicular (30%) lymphoma. Seventeen patients had prior lymphoma at other sites, and 29 had primary orbital lymphoma. Median follow-up was 46 months. Results: The median dose was 30.6 Gy; one-third received <30 Gy. Electrons were used in 9 eyes with disease confined to the conjunctiva or eyelid, and photons in 53 eyes with involvement of intraorbital tissues to cover entire orbit. Local control rate was 98% for all patients and 100% for those with indolent lymphoma. Three of the 26 patients with localized primary lymphoma failed distantly, resulting in a 5-year freedom-from-distant-relapse rate of 89%. The 5-year disease-specific and overall survival rates were 95% and 88%, respectively. Late toxicity was mainly cataract formation in patients who received radiation without lens block. Conclusions A dose of 30 Gy is sufficient for indolent orbital lymphoma. Distant relapse rate in patients with localized orbital lymphoma was lower than that reported for low-grade lymphoma presenting in other sites. Orbital radiotherapy can be used for salvage of recurrent indolent lymphoma.

  5. Radiation sensitizing and radiation protective agents in experimental radiation therapy

    SciTech Connect

    Ambrus, J.L.; Halpern, J.; Bardos, T.; Chmielwicz, Z.F.; Klein, E.

    1988-01-01

    It appears that AB-132 potentiates radiation effects, and the local application of AET (MEG) protects the intestinal tract, the bladder and the skin against radiation toxicity. Combined use of selective radiation sensitizing and protecting agents may be considered for clinical studies.

  6. Protons -- The Future of Radiation Therapy?

    NASA Astrophysics Data System (ADS)

    Avery, Steven

    2007-03-01

    Cancer is the 2^nd highest cause of death in the United States. The challenges of controlling this disease remain more difficult as the population lives longer. Proton therapy offers another choice in the management of cancer care. Proton therapy has existed since the late 1950s and the first hospital based center in the United States opened in 1990. Since that time four hospital based proton centers are treating patients with other centers either under construction or under consideration. This talk will focus on an introduction to proton therapy: it's medical advantages over current treatment modalities, accelerators and beam delivery systems, applications to clinical radiation oncology and the future outlook for proton therapy.

  7. Comparison of particle-radiation-therapy modalities

    SciTech Connect

    Fairchild, R.G.; Bond, V.P.

    1981-01-01

    The characteristics of dose distribution, beam alignment, and radiobiological advantages accorded to high LET radiation were reviewed and compared for various particle beam radiotherapeutic modalities (neutron, Auger electrons, p, ..pi../sup -/, He, C, Ne, and Ar ions). Merit factors were evaluated on the basis of effective dose to tumor relative to normal tissue, linear energy transfer (LET), and dose localization, at depths of 1, 4, and 10 cm. In general, it was found that neutron capture therapy using an epithermal neutron beam provided the best merit factors available for depths up to 8 cm. The position of fast neutron therapy on the Merit Factor Tables was consistently lower than that of other particle modalities, and above only /sup 60/Co. The largest body of clinical data exists for fast neutron therapy; results are considered by some to be encouraging. It then follows that if benefits with fast neutron therapy are real, additional gains are within reach with other modalities.

  8. Radiation Therapy -- What It Is, How It Helps

    MedlinePlus

    ... saved articles window. My Saved Articles » My ACS » Radiation Therapy -- What It Is, How It Helps Download ... to-read guide offers a basic explanation of radiation therapy. Click on the topics below to get ...

  9. 'Suicide Gene Therapy' Plus Radiation Fights Prostate Cancer: Study

    MedlinePlus

    ... nih.gov/medlineplus/news/fullstory_156217.html 'Suicide Gene Therapy' Plus Radiation Fights Prostate Cancer: Study Patients' cancer ... 14, 2015 (HealthDay News) -- A combination of "suicide gene therapy" and radiation is highly effective in treating prostate ...

  10. Unusual radiologic findings in the thorax after radiation therapy.

    PubMed

    Mesurolle, B; Qanadli, S D; Merad, M; Mignon, F; Baldeyrou, P; Tardivon, A; Lacombe, P; Vanel, D

    2000-01-01

    Radiation therapy is used to treat many intrathoracic and chest wall malignancies. A variety of changes may occur after radiation therapy to the thorax. Radiation therapy produces dramatic effects in the lung. Pulmonary necrosis is an uncommon, severe, late complication of adjuvant postoperative radiation therapy. Bronchiolitis obliterans with organizing pneumonia is a distinct clinicopathologic entity characterized by patchy, migratory, peripheral air-space infiltrates. Radiation therapy can also cause spontaneous pneumothorax, mesothelioma, and lung cancer. In the mediastinum, radiation therapy may cause thymic cysts, calcified lymph nodes, and esophageal injuries. Cardiovascular complications of radiation therapy are often delayed and insidious. Premature coronary artery stenosis occurs after radiation therapy to the mediastinum. Radiation therapy may also give rise to calcifications of the ascending aorta, pericardial disease, valvular injuries, and conduction abnormalities. Women who undergo thoracic irradiation before the age of 30 years have a high risk of developing a second breast cancer. Radiation-induced sarcomas are an infrequent but well-recognized complication of radiation therapy. Other chest wall injuries due to radiation therapy are osteochondroma and rib or clavicle fractures. Knowledge of the imaging features of injuries caused by radiation therapy can prevent misinterpretation as recurrent tumor and may facilitate further treatment. PMID:10682772

  11. Particle Radiation Therapy for Gastrointestinal Cancers.

    PubMed

    Shinoto, Makoto; Ebner, Daniel K; Yamada, Shigeru

    2016-03-01

    Particle irradiation of cancerous disease has gained great traction in recent years. The ability for particle therapy centers to deliver radiation with a highly conformal dose distribution while maintaining minimal exit or excess dose delivered to normal tissue, coupled with various biological advantages particularly found with heavy-ion beams, enables treatment of diseases inapproachable with conventional radiotherapy. Here, we present a review of the current status of particle therapy with regard to cancers of the gastrointestinal tract, including esophagus, liver, pancreas, and recurrent rectal cancer. PMID:26849660

  12. 21 CFR 892.5840 - Radiation therapy simulation system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiation therapy simulation system. 892.5840... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic or radiographic...

  13. 21 CFR 892.5840 - Radiation therapy simulation system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiation therapy simulation system. 892.5840... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic or radiographic...

  14. 21 CFR 892.5840 - Radiation therapy simulation system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiation therapy simulation system. 892.5840... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic or radiographic...

  15. 21 CFR 892.5300 - Medical neutron radiation therapy system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Medical neutron radiation therapy system. 892.5300... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5300 Medical neutron radiation therapy system. (a) Identification. A medical neutron radiation therapy system is a device intended...

  16. 21 CFR 892.5300 - Medical neutron radiation therapy system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Medical neutron radiation therapy system. 892.5300... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5300 Medical neutron radiation therapy system. (a) Identification. A medical neutron radiation therapy system is a device intended...

  17. 21 CFR 892.5300 - Medical neutron radiation therapy system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical neutron radiation therapy system. 892.5300... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5300 Medical neutron radiation therapy system. (a) Identification. A medical neutron radiation therapy system is a device intended...

  18. 21 CFR 892.5300 - Medical neutron radiation therapy system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Medical neutron radiation therapy system. 892.5300... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5300 Medical neutron radiation therapy system. (a) Identification. A medical neutron radiation therapy system is a device intended...

  19. 21 CFR 892.5300 - Medical neutron radiation therapy system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Medical neutron radiation therapy system. 892.5300... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5300 Medical neutron radiation therapy system. (a) Identification. A medical neutron radiation therapy system is a device intended...

  20. 21 CFR 892.5750 - Radionuclide radiation therapy system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radionuclide radiation therapy system. 892.5750... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification. A radionuclide radiation therapy system is a device intended to permit...

  1. 21 CFR 892.5840 - Radiation therapy simulation system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiation therapy simulation system. 892.5840... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic or radiographic...

  2. 21 CFR 892.5840 - Radiation therapy simulation system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiation therapy simulation system. 892.5840... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic or radiographic...

  3. Fishbowl Plaques.

    ERIC Educational Resources Information Center

    Lambert, Phyllis Gilchrist

    1998-01-01

    Presents an elementary art activity that successfully teaches the process of slabbing by having students create fishbowl plaques. Explains the process step-by-step beginning with a demonstration to the students along with showing previous examples. Endorses a type of clay that fires white because the glaze colors are much more vibrant. (CMK)

  4. Pulsed laser radiation therapy of skin tumors

    SciTech Connect

    Kozlov, A.P.; Moskalik, K.G.

    1980-11-15

    Radiation from a neodymium laser was used to treat 846 patients with 687 precancerous lesions or benign tumors of the skin, 516 cutaneous carcinomas, 33 recurrences of cancer, 51 melanomas, and 508 metastatic melanomas in the skin. The patients have been followed for three months to 6.5 years. No relapses have been observed during this period. Metastases to regional lymph nodes were found in five patients with skin melanoma. Pulsed laser radiation may be successfully used in the treatment of precancerous lesions and benign tumors as well as for skin carcinoma and its recurrences, and for skin melanoma. Laser radiation is more effective in the treatment of tumors inaccessible to radiation therapy and better in those cases in which surgery may have a bad cosmetic or even mutilating effect. Laser beams can be employed in conjunction with chemo- or immunotherapy.

  5. Comparison of Intensive Versus Moderate Lipid-Lowering Therapy on Fibrous Cap and Atheroma Volume of Coronary Lipid-Rich Plaque Using Serial Optical Coherence Tomography and Intravascular Ultrasound Imaging.

    PubMed

    Hou, Jingbo; Xing, Lei; Jia, Haibo; Vergallo, Rocco; Soeda, Tsunerari; Minami, Yoshiyasu; Hu, Sining; Yang, Shuang; Zhang, Shaosong; Lee, Hang; Yu, Bo; Jang, Ik-Kyung

    2016-03-01

    Despite marked clinical benefit, reduction in atheroma volume with statin therapy is minimal. Changes in plaque composition may explain this discrepancy. We aimed in the present study to assess the effect of statin therapy on coronary plaque composition and plaque volume using serial multimodality imaging. From an open-label, single-blinded study, patients with angiographically mild-to-moderate lesion were randomized to receive atorvastatin 60 (AT 60) mg or atorvastatin 20 (AT 20) mg for 12months. Optical coherence tomography was used to assess fibrous cap thickness (FCT) and intravascular ultrasound to assess atheroma burden at 3 time points: baseline, at 6 months, and at 12 months. Thirty-six lipid-rich plaques in 27 patients with AT 60mg and 30 lipid-rich plaques in 19 patients with AT 20mg were enrolled in this study. Low-density lipoprotein cholesterol level was significantly decreased at 6 months without further reduction at 12 months. AT 60mg induced greater reduction in low-density lipoprotein cholesterol compared with AT 20mg. Optical coherence tomography revealed continuous increase in FCT from baseline to 6months and to 12months in both groups. AT 60mg induced greater increase in FCT compared with AT 20mg at both follow-up points. The prevalence of thin-cap fibroatheroma and the presence of macrophage at 6 months were significantly lower in AT 60mg compared with AT 20mg. Plaque burden did not change significantly in both groups. In conclusion, both intensive and moderate statin therapy stabilizes coronary plaques, with a greater benefit in the intensive statin group. However, no significant changes in plaque volume were observed over time regardless of the intensity of statin therapy. PMID:26778524

  6. The Evolving Role of Radiation Therapy in the Management of Malignant Melanoma

    SciTech Connect

    Khan, Niloufer; Khan, Mohammad K.; Almasan, Alex; Singh, Arun D.; Macklis, Roger

    2011-07-01

    The incidence of melanoma is rising in the United States, leading to an estimated 68,720 new diagnoses and 8,650 deaths annually. The natural history involves metastases to lymph nodes, lung, liver, brain, and often to other sites. Primary treatment for melanoma is surgical excision of the primary tumor and affected lymph nodes. The role of adjuvant or definitive radiation therapy in the treatment of melanoma remains controversial, because melanoma has traditionally been viewed as a prototypical radioresistant cancer. However, recent studies suggest that under certain clinical circumstances, there may be a significant role for radiation therapy in melanoma treatment. Stereotactic radiosurgery for brain metastases has shown effective local control. High dose per fraction radiation therapy has been associated with a lower rate of locoregional recurrence of sinonasal melanoma. Plaque brachytherapy has evolved into a promising alternative to enucleation at the expense of moderate reduction in visual acuity. Adjuvant radiation therapy following lymphadenectomy in node-positive melanoma prevents local and regional recurrence. The newer clinical data along with emerging radiobiological data indicate that radiotherapy is likely to play a greater role in melanoma management and should be considered as a treatment option.

  7. Galactic Cosmic Radiation Leads to Cognitive Impairment and Increased Aβ Plaque Accumulation in a Mouse Model of Alzheimer’s Disease

    PubMed Central

    Cherry, Jonathan D.; Liu, Bin; Frost, Jeffrey L.; Lemere, Cynthia A.; Williams, Jacqueline P.; Olschowka, John A.; O’Banion, M. Kerry

    2012-01-01

    Galactic Cosmic Radiation consisting of high-energy, high-charged (HZE) particles poses a significant threat to future astronauts in deep space. Aside from cancer, concerns have been raised about late degenerative risks, including effects on the brain. In this study we examined the effects of 56Fe particle irradiation in an APP/PS1 mouse model of Alzheimer’s disease (AD). We demonstrated 6 months after exposure to 10 and 100 cGy 56Fe radiation at 1 GeV/µ, that APP/PS1 mice show decreased cognitive abilities measured by contextual fear conditioning and novel object recognition tests. Furthermore, in male mice we saw acceleration of Aβ plaque pathology using Congo red and 6E10 staining, which was further confirmed by ELISA measures of Aβ isoforms. Increases were not due to higher levels of amyloid precursor protein (APP) or increased cleavage as measured by levels of the β C-terminal fragment of APP. Additionally, we saw no change in microglial activation levels judging by CD68 and Iba-1 immunoreactivities in and around Aβ plaques or insulin degrading enzyme, which has been shown to degrade Aβ. However, immunohistochemical analysis of ICAM-1 showed evidence of endothelial activation after 100 cGy irradiation in male mice, suggesting possible alterations in Aβ trafficking through the blood brain barrier as a possible cause of plaque increase. Overall, our results show for the first time that HZE particle radiation can increase Aβ plaque pathology in an APP/PS1 mouse model of AD. PMID:23300905

  8. Radiation therapy following targeted therapy in oligometastatic renal cell carcinoma

    PubMed Central

    GRAVIS, GWENAELLE; FAURE, MARJORIE; RYBIKOWSKI, STANISLAS; DERMECHE, SLIMANE; TYRAN, MARGUERITE; CALDERON, BENOIT; THOMASSIN, JEANNE; WALZ, JOCHEN; SALEM, NAJI

    2015-01-01

    Up to 40% of patients with renal cell carcinoma (RCC) with initially localized disease eventually develop metastasis following nephrectomy. The current standard of care for metastatic RCC (mRCC) is targeted therapy. However, complete response remains rare. A state of oligometastatic disease may exist, in which metastases are present in a limited number of locations; such cases may benefit from metastasis-directed local therapy, based on the evidence supporting resection of limited-volume metastases, allowing for improved disease control. We retrospectively analyzed 7 cases of response of RCC metastases, in patients treated with targeted therapies followed by radiation therapy (RT) of residual metastatic lesions in Paoli-Calmettes Institute (Marseille, France). We analyzed disease response rates, response to sequential strategy, relapse at the irradiated locations and disease evolution. The median follow-up was 34.1 months (range, 19.2–54.5 months). No progression at the irradiated sites was observed. A total of 5 patients had stable disease at the irradiated locations at the last follow-up; 3 remained in complete remission at the assessment, and 2 were stable. Excellent local response and clinical benefit may be achieved without added toxicity. In conclusion, sequential therapeutic strategies with RT following systemic treatment using sunitinib appear to be highly effective in patients with progressive mRCC and prompt the conduction of further confirmatory trials. PMID:26807228

  9. Radiation therapy at compact Compton sources.

    PubMed

    Jacquet, Marie; Suortti, Pekka

    2015-09-01

    The principle of the compact Compton source is presented briefly. In collision with an ultrarelativistic electron bunch a laser pulse is back-scattered as hard X-rays. The radiation cone has an opening of a few mrad, and the energy bandwidth is a few percent. The electrons that have an energy of the order of a few tens of MeV either circulate in storage ring, or are injected to a linac at a frequency of 10-100 MHz. At the interaction point the electron bunch collides with the laser pulse that has been amplified in a Fabry-Perot resonator. There are several machines in design or construction phase, and projected fluxes are 10(12) to 10(14) photons/s. The flux available at 80 keV from the ThomX machine is compared with that used in the Stereotactic Synchrotron Radiation Therapy clinical trials. It is concluded that ThomX has the potential of serving as the radiation source in future radiation therapy programs, and that ThomX can be integrated in hospital environment. PMID:25752735

  10. Microwave plaque thermoradiotherapy for choroidal melanoma.

    PubMed Central

    Finger, P. T.

    1992-01-01

    Microwave thermoradiotherapy was used as a primary treatment for 44 patients with choroidal melanoma. An episcleral dish-shaped microwave antenna was placed beneath the tumour at the time of plaque brachytherapy. While temperatures were measured at the sclera, the tumour's apex was targeted to receive a minimum of 42 degrees C for 45 minutes. In addition, the patients received full or reduced doses of plaque radiotherapy. No patients have been lost to follow-up. Two eyes have been enucleated: one for rubeotic glaucoma, and one for uveitic glaucoma. Though six patients have died, only one death was due to metastatic choroidal melanoma (39 months after treatment). Clinical observations suggest that the addition of microwave heating to plaque radiation therapy of choroidal melanoma has been well tolerated. There has been a 97.7% local control rate (with a mean follow-up of 22.2 months). We have reduced the minimum tumour radiation dose (apex dose) to levels used for thermoradiotherapy of cutaneous melanomas (50 Gy/5000 rad). Within the range of this follow-up period no adverse effects which might preclude the use of this microwave heat delivery system for treatment of choroidal melanoma have been noted. Images PMID:1622949

  11. Automatic field shaping for conformal radiation therapy.

    PubMed

    Ayyangar, K

    1994-04-01

    A computer method has been developed to shape the radiation field to conform to the shape of the target as visualized through the beam's eye view (BEV) perspective for conformal radiation therapy. Initially, a series of 2D target contours to define the target size are input into the computer. These target contour data are mapped onto a 3D surface and thereafter projected onto a BEV plane. The projection's outer boundary of the target is auto-contoured. After auto-contouring, a margin is automatically added to define the radiation beam cross section. Since the BEV plane is arbitrarily oriented about the target, the beam orientation can be non-coplanar to the plane of the target contours. For a chosen beam orientation, the conformal treatment beam cross section can be generated automatically using this computer technique and output to either a laser printer, a plotter or stored on files for transfer to the linear accelerator computer system. PMID:7924269

  12. Intravascular photoacoustics for image-guidance and temperature monitoring during plasmonic photothermal therapy of atherosclerotic plaques: a feasibility study.

    PubMed

    Yeager, Doug; Chen, Yun-Sheng; Litovsky, Silvio; Emelianov, Stanislav

    2013-01-01

    Recently, combined intravascular ultrasound and photoacoustic (IVUS/IVPA) imaging has been demonstrated as a novel imaging modality capable of visualizing both morphology (via IVUS) and cellular/molecular composition (via IVPA) of atherosclerotic plaques, using both endogenous tissue absorbers and exogenous contrast agents. Plasmonic gold nanoparticles were previously utilized as IVPA contrast agents which co-localize with atherosclerotic plaques, particularly phagocytically active macrophages. The present work demonstrates the use of IVUS/IVPA imaging as a tool for localized temperature monitoring during laser heating. The temperature dependent change in IVPA signal intensity of silica-coated gold nanorod contrast agents absorbing within the near-infrared optical wavelength range is evaluated and shown to have a linear relationship, with a slope greater than that of endogenous tissue. A continuous wave laser was subsequently incorporated into the IVUS/IVPA integrated catheter and utilized to selectively heat the nanoparticles with simultaneous IVPA temperature monitoring. IVUS/IVPA, therefore, provides a platform for detection and temperature monitoring of atherosclerotic plaques through the selective heating of plasmonic gold nanoparticle contrast agents. PMID:24396514

  13. Surgical therapy of Peyronie's disease by partial plaque excision and grafting with collagen fleece: feasibility study of a new technique.

    PubMed

    Hatzichristodoulou, G; Gschwend, J E; Lahme, S

    2013-09-01

    Surgery is gold-standard for correction of Peyronie's curvature. Grafting is preferred in advanced deviations. We present our novel surgical technique and early results of grafting with collagen fleece. Patients with stable Peyronie's disease (PD) were included. Grafting was performed by a ready-to-use collagen fleece coated with tissue sealant (TachoSil, Nycomed, Konstanz, Germany), following partial plaque excision/incision. Results of correction were documented by artificial erection. In all, n=70 consecutive patients underwent surgery. Mean patient age was 56.4 years (range: 33-72); 88.6% of patients had dorsal deviation, 11.4% lateral or ventral deviation. Grafting after partial plaque excision was performed in 61 patients (87.1%), after plaque incision in 2 (2.9%) patients. In the former patients, mean operative time was 94.2?min (range: 65-165). Totally straightness was achieved in 83.6%. Three patients required surgical drainage because of subcutaneous haematoma formation. After mean early follow-up of 5.2 days (range: 2-15), glans sensation was normal in 56 patients (91.8%). Seven patients (10.0%) underwent Nesbit procedure alone. Grafting by collagen fleece in PD is feasible and promising. Major advantages are decreased operative times and easy application. Moreover, an additional haemostatic effect is provided. However, long-term clinical outcomes are necessary to confirm these encouraging findings. PMID:23446807

  14. Intravascular Photoacoustics for Image-Guidance and Temperature Monitoring During Plasmonic Photothermal Therapy of Atherosclerotic Plaques: A Feasibility Study

    PubMed Central

    Yeager, Doug; Chen, Yun-Sheng; Litovsky, Silvio; Emelianov, Stanislav

    2014-01-01

    Recently, combined intravascular ultrasound and photoacoustic (IVUS/IVPA) imaging has been demonstrated as a novel imaging modality capable of visualizing both morphology (via IVUS) and cellular/molecular composition (via IVPA) of atherosclerotic plaques, using both endogenous tissue absorbers and exogenous contrast agents. Plasmonic gold nanoparticles were previously utilized as IVPA contrast agents which co-localize with atherosclerotic plaques, particularly phagocytically active macrophages. The present work demonstrates the use of IVUS/IVPA imaging as a tool for localized temperature monitoring during laser heating. The temperature dependent change in IVPA signal intensity of silica-coated gold nanorod contrast agents absorbing within the near-infrared optical wavelength range is evaluated and shown to have a linear relationship, with a slope greater than that of endogenous tissue. A continuous wave laser was subsequently incorporated into the IVUS/IVPA integrated catheter and utilized to selectively heat the nanoparticles with simultaneous IVPA temperature monitoring. IVUS/IVPA, therefore, provides a platform for detection and temperature monitoring of atherosclerotic plaques through the selective heating of plasmonic gold nanoparticle contrast agents. PMID:24396514

  15. Adjunctive dental therapy via tooth plaque reduction and gingivitis treatment by blue light-emitting diodes tooth brushing

    NASA Astrophysics Data System (ADS)

    Genina, Elina A.; Titorenko, Vladimir A.; Belikov, Andrey V.; Bashkatov, Alexey N.; Tuchin, Valery V.

    2015-12-01

    The efficacy of blue light-emitting toothbrushes (B-LETBs) (405 to 420 nm, power density 2 mW/cm2) for reduction of dental plaques and gingival inflammation has been evaluated. Microbiological study has shown the multifactor therapeutic action of the B-LETBs on oral pathological microflora: in addition to partial mechanical removal of bacteria, photodynamic action suppresses them up to 97.5%. In the pilot clinical studies, subjects with mild to moderate gingivitis have been randomly divided into two groups: a treatment group that used the B-LETBs and a control group that used standard toothbrushes. Indices of plaque, gingival bleeding, and inflammation have been evaluated. A significant improvement of all dental indices in comparison with the baseline (by 59%, 66%, and 82% for plaque, gingival bleeding, and inflammation, respectively) has been found. The treatment group has demonstrated up to 50% improvement relative to the control group. We have proposed the B-LETBs to serve for prevention of gingivitis or as an alternative to conventional antibiotic treatment of this disease due to their effectiveness and the absence of drug side effects and bacterial resistance.

  16. Pirfenidone enhances the efficacy of combined radiation and sunitinib therapy

    SciTech Connect

    Choi, Seo-Hyun; Nam, Jae-Kyung; Jang, Junho; Lee, Hae-June Lee, Yoon-Jin

    2015-06-26

    Radiotherapy is a widely used treatment for many tumors. Combination therapy using anti-angiogenic agents and radiation has shown promise; however, these combined therapies are reported to have many limitations in clinical trials. Here, we show that radiation transformed tumor endothelial cells (ECs) to fibroblasts, resulting in reduced vascular endothelial growth factor (VEGF) response and increased Snail1, Twist1, Type I collagen, and transforming growth factor (TGF)-β release. Irradiation of radioresistant Lewis lung carcinoma (LLC) tumors greater than 250 mm{sup 3} increased collagen levels, particularly in large tumor vessels. Furthermore, concomitant sunitinib therapy did not show a significant difference in tumor inhibition versus radiation alone. Thus, we evaluated multimodal therapy that combined pirfenidone, an inhibitor of TGF-induced collagen production, with radiation and sunitinib treatment. This trimodal therapy significantly reduced tumor growth, as compared to radiation alone. Immunohistochemical analysis revealed that radiation-induced collagen deposition and tumor microvessel density were significantly reduced with trimodal therapy, as compared to radiation alone. These data suggest that combined therapy using pirfenidone may modulate the radiation-altered tumor microenvironment, thereby enhancing the efficacy of radiation therapy and concurrent chemotherapy. - Highlights: • Radiation changes tumor endothelial cells to fibroblasts. • Radio-resistant tumors contain collagen deposits, especially in tumor vessels. • Pirfenidone enhances the efficacy of combined radiation and sunitinib therapy. • Pirfenidone reduces radiation-induced collagen deposits in tumors.

  17. Intraoperative radiation therapy in recurrent ovarian cancer

    SciTech Connect

    Yap, O.W. Stephanie . E-mail: stbeast@stanford.edu; Kapp, Daniel S.; Teng, Nelson N.H.; Husain, Amreen

    2005-11-15

    Purpose: To evaluate disease outcomes and complications in patients with recurrent ovarian cancer treated with cytoreductive surgery and intraoperative radiation therapy (IORT). Methods and Materials: A retrospective study of 24 consecutive patients with ovarian carcinoma who underwent secondary cytoreduction and intraoperative radiation therapy at our institution between 1994 and 2002 was conducted. After optimal cytoreductive surgery, IORT was delivered with orthovoltage X-rays (200 kVp) using individually sized and beveled cone applications. Outcomes measures were local control of disease, progression-free interval, overall survival, and treatment-related complications. Results: Of these 24 patients, 22 were available for follow-up analysis. Additional treatment at the time of and after IORT included whole abdominopelvic radiation, 9; pelvic or locoregional radiation, 5; chemotherapy, 6; and no adjuvant treatment, 2. IORT doses ranged from 9-14 Gy (median, 12 Gy). The anatomic sites treated were pelvis (sidewalls, vaginal cuff, presacral area, anterior pubis), para-aortic and paracaval lymph node beds, inguinal region, or porta hepatitis. At a median follow-up of 24 months, 5 patients remain free of disease, whereas 17 patients have recurred, of whom 4 are alive with disease and 13 died from disease. Five patients recurred within the radiation fields for a locoregional relapse rate of 32% and 12 patients recurred at distant sites with a median time to recurrence of 13.7 months. Five-year overall survival was 22% with a median survival of 26 months from time of IORT. Nine patients (41%) experienced Grade 3 toxicities from their treatments. Conclusion: In carefully selected patients with locally recurrent ovarian cancer, combined IORT and tumor reductive surgery is reasonably tolerated and may contribute to achieving local control and disease palliation.

  18. Methods for implementing microbeam radiation therapy

    DOEpatents

    Dilmanian, F. Avraham; Morris, Gerard M.; Hainfeld, James F.

    2007-03-20

    A method of performing radiation therapy includes delivering a therapeutic dose such as X-ray only to a target (e.g., tumor) with continuous broad beam (or in-effect continuous) using arrays of parallel planes of radiation (microbeams/microplanar beams). Microbeams spare normal tissues, and when interlaced at a tumor, form a broad-beam for tumor ablation. Bidirectional interlaced microbeam radiation therapy (BIMRT) uses two orthogonal arrays with inter-beam spacing equal to beam thickness. Multidirectional interlaced MRT (MIMRT) includes irradiations of arrays from several angles, which interleave at the target. Contrast agents, such as tungsten and gold, are administered to preferentially increase the target dose relative to the dose in normal tissue. Lighter elements, such as iodine and gadolinium, are used as scattering agents in conjunction with non-interleaving geometries of array(s) (e.g., unidirectional or cross-fired (intersecting) to generate a broad beam effect only within the target by preferentially increasing the valley dose within the tumor.

  19. Role for radiation therapy in melanoma.

    PubMed

    Shi, Wenyin

    2015-04-01

    Although melanoma is generally considered a relative radioresistant tumor, radiation therapy (RT) remains a valid and effective treatment option in definitive, adjuvant, and palliative settings. Definitive RT is generally only used in inoperable patients. Despite a high-quality clinical trial showing adjuvant RT following lymphadenectomy in node-positive melanoma patients prevents local and regional recurrence, the role of adjuvant RT in the treatment of melanoma remains controversial and is underused. RT is highly effective in providing symptom palliation for metastatic melanoma. RT combined with new systemic options, such as immunotherapy, holds promise and is being actively evaluated. PMID:25769715

  20. [Postoperative radiation therapy in lung carcinom].

    PubMed

    Bouchaab, H; Peters, S; Ozsahin, M; Peguret, N; Gonzales, M; Lovis, A

    2014-05-21

    Locally advanced non-small-cell lung carcinoma (NSCLC) is a very heterogeous disease, the role of postoperative radiation therapy (PORT) in pN2 patients with completly resected NSCLC remains controversial. Although an improvment in local control has been described in several studies, the effect on survival has been contradictory or inconclusive. Retrospective evaluation suggest a positive effect of PORT in high risk patients with pN2 disease: RI-resected NSCLC, bulky and multilevel N2. However further evaluation of PORT in prospectively randomized studies in completely resected pN2 NSCLC is needed. PMID:24941680

  1. Prostatic carcinoma: rectal bleeding after radiation therapy

    SciTech Connect

    Kagan, A.R.; Steckel, R.J.

    1981-06-01

    A 64-year-old man had a prostatic nodule on routine physical examination; per-rectal needle biopsies revealed a single focus of well differentiated adenocarcinoma. The patient had no history of urinary obstruction or of bowel difficulties. Accordingly, this was clinical stage II carcinoma of the prostate. The patient chose to receive external radiation therapy and was given small-field rotational treatment to a dose of 7000 rad (70 Gy) at a rate of 800 rad (8 Gy) weekly. Late in treatment, he experienced transitory diarrhea with flatulence, but this cleared with completion of treatment. Twenty months later he began to note frequent soft bowel movements, occasionally with red blood. At sigmoidoscopy 24 months after completion of treatment, the rectal mucosa was noted to be friable with minimal bleeding, presumably the result of radiation proctitis.

  2. New irradiation geometry for microbeam radiation therapy

    NASA Astrophysics Data System (ADS)

    Bräuer-Krisch, E.; Requardt, H.; Régnard, P.; Corde, S.; Siegbahn, E.; LeDuc, G.; Brochard, T.; Blattmann, H.; Laissue, J.; Bravin, A.

    2005-07-01

    Microbeam radiation therapy (MRT) has the potential to treat infantile brain tumours when other kinds of radiotherapy would be excessively toxic to the developing normal brain. MRT uses extraordinarily high doses of x-rays but provides unusual resistance to radioneurotoxicity, presumably from the migration of endothelial cells from 'valleys' into 'peaks', i.e., into directly irradiated microslices of tissues. We present a novel irradiation geometry which results in a tolerable valley dose for the normal tissue and a decreased peak-to-valley dose ratio (PVDR) in the tumour area by applying an innovative cross-firing technique. We propose an MRT technique to orthogonally crossfire two arrays of parallel, nonintersecting, mutually interspersed microbeams that produces tumouricidal doses with small PVDRs where the arrays meet and tolerable radiation doses to normal tissues between the microbeams proximal and distal to the tumour in the paths of the arrays.

  3. Particle Radiation Therapy for Gastrointestinal Malignancies

    PubMed Central

    Meyer, Jeffrey J.; Willett, Christopher G.

    2007-01-01

    Treatment-related toxicity is common in the radiotherapeutic management of cancers of the gastrointestinal tract. These toxicities can diminish treatment efficacy by necessitating treatment breaks, limiting the radiation dose that can be delivered, and hindering concomitant use of chemotherapy and targeted drug agents. Many efforts have focused on widening the gap between the likelihood of tumor control and the likelihood of toxicities associated with radiation. Use of particles that exhibit a Bragg peak phenomenon in their interactions with tissue, such as protons, heavier ions like carbon ions, and pions, is one means of concentrating radiation dose in tumors and away from normal tissues. Neutron beams have also been used in the treatment of gastrointestinal cancers in an effort to take advantage of their potent biologic effects. This report reviews basic particle radiation physics and biology, as well as the clinical experience with protons, heavier ions, pions, and neutrons in the treatment of various gastrointestinal malignancies. Potential future directions in clinical research with particle therapy are discussed. PMID:19360149

  4. Clinical applications of continuous infusion chemotherapy ahd concomitant radiation therapy

    SciTech Connect

    Rosenthal, C.J.; Rotman, M.

    1986-01-01

    This book presents information on the following topics: theoretical basis and clinical applications of 5-FU as a radiosensitizer; treatment of hepatic metastases from gastro intestingal primaries with split course radiation therapy; combined modality therapy with 5-FU, Mitomycin-C and radiation therapy for sqamous cell cancers; treatment of bladder carcinoma with concomitant infusion chemotherapy and irradiation; a treatment of invasiv bladder cancer by the XRT/5FU protocol; concomitant radiation therapy and doxorubicin by continuous infusion in advanced malignancies; cis platin by continuous infusion with concurrent radiation therapy in malignant tumors; combination of radiation with concomitant continuous adriamycin infusion in a patient with partially excised pleomorphic soft tissue sarcoma of the lower extremeity; treatment of recurrent carcinoma of the paranasal sinuses using concomitant infusion cis-platinum and radiation therapy; hepatic artery infusion for hepatic metastases in combination with hepatic resection and hepatic radiation; study of simultaneous radiation therapy, continuous infusion, 5FU and bolus mitomycin-C; cancer of the esophagus; continuous infusion VP-16, bolus cis-platinum and simultaneous radiation therapy as salvage therapy in small cell bronchogenic carcinoma; and concomitant radiation, mitomycin-C and 5-FU infusion in gastro intestinal cancer.

  5. Serial Optical Coherence Tomography and Intravascular Ultrasound Analysis of Gender Difference in Changes of Plaque Phenotype in Response to Lipid-Lowering Therapy.

    PubMed

    Minami, Yoshiyasu; Hou, Jingbo; Xing, Lei; Jia, Haibo; Hu, Sining; Vergallo, Rocco; Soeda, Tsunenari; Lee, Hang; Zhang, Shaosong; Yu, Bo; Jang, Ik-Kyung

    2016-06-15

    Although the clinical benefit of statins have been demonstrated in both genders, gender differences in the response to statin therapy on plaque morphologic changes have not been reported. A total of 66 nonculprit plaques from 46 patients who had serial image acquisition at baseline, 6 months, and 12 months by both optical coherence tomography and intravascular ultrasound (IVUS) were included. Patients were treated with atorvastatin 60 mg (AT60) or 20 mg (AT20). The baseline characteristics were similar between women (n = 16) and men (n = 30) except for age (59.3 ± 6.8 vs 52.5 ± 10.6 years, p = 0.027) and smoking status (12.5% vs 70.0%, p <0.001). The change in fibrous cap thickness (FCT) at 12 months was significant in both groups (108.8 ± 87.4 μm, p <0.001, 91.3 ± 70.1 μm, p <0.001, respectively) without significant difference between the groups (p = 0.437). The percent change in mean lipid arc at 6 months was significantly greater in women than that in men (-12.8 ± 18.8% vs -1.56 ± 21.8%, p = 0.040). In women, the percent change of FCT in the AT20 group was similar to that in the AT60 group (182.5 ± 199.5% vs 192.9 ± 149.7%, p = 0.886). However, in men, the percent change of FCT in the AT20 group was significantly smaller than that in the AT60 group (92.2 ± 90.5% vs 225.9 ± 104.3%, p <0.001). No significant change in percent atheroma volume by IVUS was seen at 12 months in both women and men. In conclusion, statin therapy was effective in both genders for plaque stabilization at 12-month follow-up. High-intensity statin therapy may be particularly important in men. PMID:27138187

  6. Mapping the literature of radiation therapy

    PubMed Central

    Delwiche, Frances A.

    2013-01-01

    Objective: This study characterizes the literature of the radiation therapy profession, identifies the journals most frequently cited by authors writing in this discipline, and determines the level of coverage of these journals by major bibliographic indexes. Method: Cited references from three discipline-specific source journals were analyzed according to the Mapping the Literature of Allied Health Project Protocol of the Nursing and Allied Health Resources Section of the Medical Library Association. Bradford's Law of Scattering was applied to all journal references to identify the most frequently cited journal titles. Results: Journal references constituted 77.8% of the total, with books, government documents, Internet sites, and miscellaneous sources making up the remainder. Although a total of 908 journal titles were cited overall, approximately one-third of the journal citations came from just 11 journals. MEDLINE and Scopus provided the most comprehensive indexing of the journal titles in Zones 1 and 2. The source journals were indexed only by CINAHL and Scopus. Conclusion: The knowledgebase of radiation therapy draws heavily from the fields of oncology, radiology, medical physics, and nursing. Discipline-specific publications are not currently well covered by major indexing services, and those wishing to conduct comprehensive literature searches should search multiple resources. PMID:23646027

  7. Collimator design for experimental minibeam radiation therapy

    SciTech Connect

    Babcock, Kerry; Sidhu, Narinder; Kundapur, Vijayananda; Ali, Kaiser

    2011-04-15

    Purpose: To design and optimize a minibeam collimator for minibeam radiation therapy studies using a 250 kVp x-ray machine as a simulated synchrotron source. Methods: A Philips RT250 orthovoltage x-ray machine was modeled using the EGSnrc/BEAMnrc Monte Carlo software. The resulting machine model was coupled to a model of a minibeam collimator with a beam aperture of 1 mm. Interaperture spacing and collimator thickness were varied to produce a minibeam with the desired peak-to-valley ratio. Results: Proper design of a minibeam collimator with Monte Carlo methods requires detailed knowledge of the x-ray source setup. For a cathode-ray tube source, the beam spot size, target angle, and source shielding all determine the final valley-to-peak dose ratio. Conclusions: A minibeam collimator setup was created, which can deliver a 30 Gy peak dose minibeam radiation therapy treatment at depths less than 1 cm with a valley-to-peak dose ratio on the order of 23%.

  8. Optimum radiation source for radiation therapy of skin cancer.

    PubMed

    Safigholi, Habib; Song, William Y; Meigooni, Ali S

    2015-01-01

    Several different applicators have been designed for treatment of skin cancers, such as scalp, hand, and legs using Ir-192 HDR brachytherapy sources (IR-HDRS), miniature electronic brachytherapy sources (eBT), and external electron beam radiation therapy (EEBRT). Although, all of these methodologies may deliver the desired radiation dose to the skin, but the dose to the underlying bone may become the limiting factor for selection of the optimum treatment technique. In this project, dose to the underlying bone has been evaluated as a function of the radiation type, thickness of the bone, and thickness of the soft tissue on top of bone, assuming the same radiation dose delivery to the skin. These evaluations are performed using Monte Carlo (MC) simulation technique with MCNP5 code. The results of these investigations indicate that, for delivery of the same skin dose with a 50keV eBT, 4 MeV or 6 MeV EEBRT techniques, the average doses received by the underlying bones are 5.31, 2, or 1.75 times the dose received from IR-HDRS technique, respectively. These investigations indicate that, for the treatment of skin cancer condition with bone immediately beneath skin, the eBT technique may not be the most suitable technique, as it may lead to excessive bone dose relative to IR-HDRS and 6 MeV or 4 MeV electron beams. PMID:26699302

  9. Post-Radiation Therapy Imaging Appearances in Cervical Carcinoma.

    PubMed

    Papadopoulou, Ioanna; Stewart, Victoria; Barwick, Tara D; Park, Won-Ho Edward; Soneji, Neil; Rockall, Andrea G; Bharwani, Nishat

    2016-01-01

    Locally advanced and node-positive cervical cancers are usually treated with external beam radiation therapy and intracavitary brachytherapy with concomitant chemotherapy. In patients with locally advanced cervical cancer, imaging plays a vital role in pretreatment planning, assessment of primary tumor response to treatment, follow-up, and evaluation of treatment-related complications. Radiation therapy planning is crucial to successful local and regional control of disease. Patient selection criteria for radiation therapy with concomitant chemotherapy are described, as is assessment of treatment response of the primary cervical tumor at magnetic resonance (MR) imaging. Image interpretation can be challenging because of radiation therapy-related changes in the pelvic organs. Expected changes in the bladder, bowel, and bone marrow after radiation therapy are described, and multimodality imaging findings at computed tomography, MR imaging, and fluorine 18 fluorodeoxyglucose positron emission tomography are illustrated. Complications after radiation therapy have declined over recent years because of targeted radiation therapy. These complications can be divided into acute and chronic effects, where acute toxic effects occur within weeks of treatment. Chronic complications include cervical stenosis, small bowel stricture, fistula formation, and insufficiency fractures. Imaging is an essential tool in the care of patients with cervical cancer treated with chemotherapy and radiation therapy. The reporting radiologist should be familiar with the expected imaging appearances of the pelvic organs after radiation therapy, as well as potential complications, to avoid pitfalls in image interpretation. (©)RSNA, 2016. PMID:26849153

  10. Radiation Therapy for Prostate Cancer May Carry Certain Risks

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_157587.html Radiation Therapy for Prostate Cancer May Carry Certain Risks ... 3, 2016 THURSDAY, March 3, 2016 (HealthDay News) -- Radiation treatment for prostate cancer may put men at ...

  11. [Preoperative radiation therapy for rectal cancer. personal experience

    PubMed

    Mayer, A; Patyánik, M; Kegye, A; Mészáros, E

    2001-01-01

    PURPOSE: Comparison of the effectiveness of preoperative and "sandwich" (preoperative and postoperative) radiation therapy in the treatment of midrectum and lower rectum carcinoma, based on a prospective clinical trial. MATERIAL AND METHOD: Over the period between 1990 and 1997, we treated 115 patients suffering from mid-rectum and lower rectum carcinoma at the Budapest Oncoradiological Centre, using sandwich therapy (22.5 Gy preoperative-27.5 Gy postoperative) in the case of 36 patients and 36 Gy preoperative radiation therapy in the case of 79 patients with external-beam megavoltage therapy with mostly telecobalt radiation and to a smaller number of cases 6 MV energy. The external-beam radiation therapy was nearly always applied with a 4-field box technique, and radical surgery was performed within 10 days following the preoperative radiation treatment. Effectiveness was evaluated in terms of a Log-Rank and Peto-Wilcoxon tests and the Kaplan-Meier survival curve. RESULTS: The effectiveness of the different therapies was compared in terms of the percentage of local failure and the rate of disease-free survival. The results show that when using the "sandwich" radiation therapy local failure is expected to occur in 13.8% of all cases, compared with 17.7%, when only preoperative radiation therapy is used. In terms of five-year disease-free survival, the sandwich therapy seems to be better, but for a higher number of years, namely 7.5, the preoperative radiation therapy yielded better results. CONCLUSION: In terms of local failure, the effectiveness of the preoperative and the "sandwich" radiation therapies for the treatment of mid-rectum and lower rectum carcinoma was nearly identical, while preoperative radiation therapy provided longer disease-free survival. Further trials using multivariation analysis need to be performed to evaluate the two types of radiation treatments, taking into account other parameters, such as grading, age and lymphatic spread. PMID:12050699

  12. Film Dosimetry for Intensity Modulated Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Benites-Rengifo, J.; Martínez-Dávalos, A.; Celis, M.; Lárraga, J.

    2004-09-01

    Intensity Modulated Radiation Therapy (IMRT) is an oncology treatment technique that employs non-uniform beam intensities to deliver highly conformal radiation to the targets while minimizing doses to normal tissues and critical organs. A key element for a successful clinical implementation of IMRT is establishing a dosimetric verification process that can ensure that delivered doses are consistent with calculated ones for each patient. To this end we are developing a fast quality control procedure, based on film dosimetry techniques, to be applied to the 6 MV Novalis linear accelerator for IMRT of the Instituto Nacional de Neurología y Neurocirugía (INNN) in Mexico City. The procedure includes measurements of individual fluence maps for a limited number of fields and dose distributions in 3D using extended dose-range radiographic film. However, the film response to radiation might depend on depth, energy and field size, and therefore compromise the accuracy of measurements. In this work we present a study of the dependence of Kodak EDR2 film's response on the depth, field size and energy, compared with those of Kodak XV2 film. The first aim is to devise a fast and accurate method to determine the calibration curve of film (optical density vs. doses) commonly called a sensitometric curve. This was accomplished by using three types of irradiation techniques: Step-and-shoot, dynamic and static fields.

  13. Exposure Risks Among Children Undergoing Radiation Therapy: Considerations in the Era of Image Guided Radiation Therapy.

    PubMed

    Hess, Clayton B; Thompson, Holly M; Benedict, Stanley H; Seibert, J Anthony; Wong, Kenneth; Vaughan, Andrew T; Chen, Allen M

    2016-04-01

    Recent improvements in toxicity profiles of pediatric oncology patients are attributable, in part, to advances in the field of radiation oncology such as intensity modulated radiation (IMRT) and proton therapy (IMPT). While IMRT and IMPT deliver highly conformal dose to targeted volumes, they commonly demand the addition of 2- or 3-dimensional imaging for precise positioning-a technique known as image guided radiation therapy (IGRT). In this manuscript we address strategies to further minimize exposure risk in children by reducing effective IGRT dose. Portal X rays and cone beam computed tomography (CBCT) are commonly used to verify patient position during IGRT and, because their relative radiation exposure is far less than the radiation absorbed from therapeutic treatment beams, their sometimes significant contribution to cumulative risk can be easily overlooked. Optimizing the conformality of IMRT/IMPT while simultaneously ignoring IGRT dose may result in organs at risk being exposed to a greater proportion of radiation from IGRT than from therapeutic beams. Over a treatment course, cumulative central-axis CBCT effective dose can approach or supersede the amount of radiation absorbed from a single treatment fraction, a theoretical increase of 3% to 5% in mutagenic risk. In select scenarios, this may result in the underprediction of acute and late toxicity risk (such as azoospermia, ovarian dysfunction, or increased lifetime mutagenic risk) in radiation-sensitive organs and patients. Although dependent on variables such as patient age, gender, weight, body habitus, anatomic location, and dose-toxicity thresholds, modifying IGRT use and acquisition parameters such as frequency, imaging modality, beam energy, current, voltage, rotational degree, collimation, field size, reconstruction algorithm, and documentation can reduce exposure, avoid unnecessary toxicity, and achieve doses as low as reasonably achievable, promoting a culture and practice of "gentle IGRT." PMID:27026304

  14. Radiation therapy for primary vaginal carcinoma

    PubMed Central

    Murakami, N.; Kasamatsu, T.; Sumi, M.; Yoshimura, R.; Takahashi, K.; Inaba, K.; Morota, M.; Mayahara, H.; Ito, Y.; Itami, J.

    2013-01-01

    Brachytherapy plays a significant role in the management of cervical cancer, but the clinical significance of brachytherapy in the management of vaginal cancer remains to be defined. Thus, a single institutional experience in the treatment of primary invasive vaginal carcinoma was reviewed to define the role of brachytherapy. We retrospectively reviewed the charts of 36 patients with primary vaginal carcinoma who received definitive radiotherapy between 1992 and 2010. The treatment modalities included high-dose-rate intracavitary brachytherapy alone (HDR-ICBT; two patients), external beam radiation therapy alone (EBRT; 14 patients), a combination of EBRT and HDR-ICBT (10 patients), or high-dose-rate interstitial brachytherapy (HDR-ISBT; 10 patients). The median follow-up was 35.2 months. The 2-year local control rate (LCR), disease-free survival (DFS), and overall survival (OS) were 68.8%, 55.3% and 73.9%, respectively. The 2-year LCR for Stage I, II, III and IV was 100%, 87.5%, 51.5% and 0%, respectively (P = 0.007). In subgroup analysis consisting only of T2–T3 disease, the use of HDR-ISBT showed marginal significance for favorable 5-year LCR (88.9% vs 46.9%, P = 0.064). One patient each developed Grade 2 proctitis, Grade 2 cystitis, and a vaginal ulcer. We conclude that brachytherapy can play a central role in radiation therapy for primary vaginal cancer. Combining EBRT and HDR-ISBT for T2–T3 disease resulted in good local control. PMID:23559599

  15. Analysis of treatment results in 36 children with retinoblastoma treated by scleral plaque irradiation

    SciTech Connect

    Amendola, B.E.; Markoe, A.M.; Augsburger, J.J.; Karlsson, U.L.; Giblin, M.; Shields, J.A.; Brady, L.W.; Woodleigh, R.

    1989-07-01

    This is a retrospective analysis of treatment results in 36 patients with retinoblastoma treated by the Radiation Oncology Department of Hahnemann University Hospital and the Division of Oncology of Wills Eye Hospital between January 1975 and December 1986. There were 14 females and 22 males; ages ranged from 2 months to 4 1/2 years of age at presentation. Leukocoria was the most common clinical sign of presentation. These patients were treated with external beam radiation therapy in combination with scleral plaque irradiation in 20 patients and with scleral plaque alone in 16 patients. Cobalt-60, Iodine-125, Iridium-192, and Ruthenium-106, scleral plaques were used. The dose delivered to the mid plane of the globe was 40 Gy and the scleral dose adjacent to the plaque was in the range of 180-200 Gy. The treatment was successful in 30 of 36 patients. Complications of radiation therapy were minimal in patients treated by scleral plaque alone. The advantages of this treatment modality are discussed.

  16. Understanding Radiation Therapy: A Guide for Patients and Families

    MedlinePlus

    ... My Saved Articles » My ACS » A Guide to Radiation Therapy Download Printable Version [PDF] » ( En español ) You’ ... and you and your doctor have agreed that radiation therapy is your best choice – either alone or ...

  17. Virtual reality in radiation therapy training.

    PubMed

    Boejen, Annette; Grau, Cai

    2011-09-01

    Integration of virtual reality (VR) in clinical training programs is a novel tool in radiotherapy. This paper presents a review of the experience with VR and Immersive visualization in 3D perspective for planning and delivery of external radiotherapy. Planning and delivering radiation therapy is a complex process involving physicians, physicists, radiographers and radiation therapists/nurses (RTT's). The specialists must be able to understand spatial relationships in the patient anatomy. Although still in its infancy, VR tools have become available for radiotherapy training, enabling students to simulate and train clinical situations without interfering with the clinical workflow, and without the risk of making errors. Immersive tools like a 3D linear accelerator and 3D display of dose distributions have been integrated into training, together with IT-labs with clinical software. Training in a VR environment seems to be cost-effective for the clinic. Initial reports suggest that 3D display of dose distributions may improve treatment planning and decision making. Whether VR training qualifies the students better than conventional training is still unsettled, but the first results are encouraging. PMID:20724144

  18. intraoperative radiation therapy part 2. Clinical results.

    PubMed

    Calvo, Felipe A; Meirino, Rosa M; Orecchia, Roberto

    2006-08-01

    Intraoperative radiation therapy (IORT) has been used for over 30 years in Asia, Europe and America as a supplementary activity in the treatment of cancer patients with promising results. Modern IORT is carried out with electron beams (IOERT) produced by a linear accelerator generally used for external beam irradiation (EBRT) or a specialized mobile electron accelerator. HDR brachytherapy (HDR-IORT) has also been applied on selected locations. Retrospective analysis of clinical experiences in cancer sites such as operable pancreatic tumour, locally advanced/recurrent rectal cancer, head and neck carcinomas, sarcomas and cervical cancer are consistent with local tumour control promotion compared to similar clinical experiences without IORT. New emerging indications such as the treatment of breast cancer are presented. The IORT component of the therapeutical approach allows intensification of the total radiation dose without additional exposure of healthy tissues and improves dose-deposit homogeneity and precision. Results of the application of IORT on selected disease sites are presented with an analysis on future possibilities. To improve the methodology, clinical trials are required with multivariate analysis including patient, tumour and treatment characteristics, prospective evaluation of early and late toxicity, patterns of tumour recurrence and overall patient outcome. PMID:16859922

  19. Ultraviolet radiation therapy and UVR dose models

    SciTech Connect

    Grimes, David Robert

    2015-01-15

    Ultraviolet radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to ultraviolet (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative ultraviolet dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for ultraviolet phototherapy are also examined, and the need for an accurate computational dose estimation method in ultraviolet phototherapy is discussed.

  20. Coronary artery disease following mediastinal radiation therapy

    SciTech Connect

    Annest, L.S.; Anderson, R.P.; Li, W.; Hafermann, M.D.

    1983-02-01

    Coronary artery disease occurred in four young men (mean age 41 years) who had received curative irradiation therapy for mediastinal malignancies 12 to 18 (mean 15) years previously. None was at high risk for developing coronary artery disease by Framingham criteria. Angiography demonstrated proximal coronary artery disease with normal distal vessels. Distribution of the lesions correlated with radiation dosimetry in that vessels exposed to higher radiation intensity were more frequently diseased. Three patients had coronary bypass grafting for intractable angina and are asymptomatic at 10 to 43 months. A total of 163 patients underwent mediastinal irradiation for lymphoma or thymoma between 1959 and 1980. Among the 29 who survived 10 or more years, five (18%) developed severe coronary artery disease, implicating thoracic radiotherapy as an important risk factor. Because of the importance of mantle irradiation in the treatment of lymphomas, the prevalence of these neoplasms, and the survival patterns following treatment, many long-term survivors may be at increased risk for the development of coronary artery disease. Recognition of the relationship between radiotherapy and coronary artery disease may lead to earlier diagnosis and more timely intervention. Standard surgical treatment may be particularly beneficial because of the relative youth of most of these patients and because the proximal distribution of typical lesions increases the likelihood of complete revascularization.

  1. Rationale of mechanical plaque control.

    PubMed

    Westfelt, E

    1996-03-01

    Patients who have received extensive periodontal treatment also demonstrate a high susceptibility to periodontal disease. Maintenance of periodontal health following therapy includes a lifelong supportive care consisting of daily removal of the microbial plaque by the patient, supplemented by professional care in an individually designed programme. Mechanical supragingival plaque control by self care is of utmost importance. The goal is to create a positive attitude by information and motivation to give the patient knowledge and confidence. The patient should be advised to use appropriate aids and technique. A soft brush, an interspace brush, interdental tooth brushes or tooth picks are recommended in periodontal patients. Professional tooth cleaning involves removal of supragingival plaque from all tooth surfaces using mechanically driven instruments and fluoride prophy paste and, when indicated, removal of calculus and subgingival plaque. Disclosing solution is used to visualize the plaque to the patient and to the clinician in order to reinforce instruction in oral hygiene. Oral hygiene measures alone seem to have limited effect on subgingival microflora in cases of severe disease. In shallow and moderately deep pockets a good plaque control can change the subgingival flora towards a more "healthy" composition. Subgingival plaque removal is performed with hand- and/or ultrasonic instruments. Cracks within the cementum, grooves, fissures, resorption lacunae, furcations may create difficulties in cleaning the root surface. Ultrasonic instrumentation has a beneficial effect in creating a smooth surface without extensive removal of cementum. Besides, the cavitational activity contributes to plaque removal which makes the instrument further suitable during maintenance therapy. The result of the debridement is assessed on the healing response in the tissues. The frequency of maintenance visits must be given on an individual basis according to the needs of every special patient. The visit includes plaque evaluation (disclosion), oral hygiene instruction, probing depth measurements, registration of bleeding on probing, scaling (plaque removal) if indicated, tooth polishing, fluoride application and radiographs if indicated. The goal is to identify and treat signs of recurrence of periodontal disease in order to prevent further loss of attachment. PMID:8707987

  2. Study design and rationale of "Synergistic Effect of Combination Therapy with Cilostazol and ProbUcol on Plaque Stabilization and Lesion REgression (SECURE)" study: a double-blind randomised controlled multicenter clinical trial

    PubMed Central

    2011-01-01

    Background Probucol, a cholesterol-lowering agent that paradoxically also lowers high-density lipoprotein cholesterol has been shown to prevent progression of atherosclerosis. The antiplatelet agent cilostazol, which has diverse antiatherogenic properties, has also been shown to reduce restenosis in previous clinical trials. Recent experimental studies have suggested potential synergy between probucol and cilostazol in preventing atherosclerosis, possibly by suppressing inflammatory reactions and promoting cholesterol efflux. Methods/design The Synergistic Effect of combination therapy with Cilostazol and probUcol on plaque stabilization and lesion REgression (SECURE) study is designed as a double-blind, randomised, controlled, multicenter clinical trial to investigate the effect of cilostazol and probucol combination therapy on plaque volume and composition in comparison with cilostazol monotherapy using intravascular ultrasound and Virtual Histology. The primary end point is the change in the plaque volume of index intermediate lesions between baseline and 9-month follow-up. Secondary endpoints include change in plaque composition, neointimal growth after implantation of stents at percutaneous coronary intervention target lesions, and serum levels of lipid components and biomarkers related to atherosclerosis and inflammation. A total of 118 patients will be included in the study. Discussion The SECURE study will deliver important information on the effects of combination therapy on lipid composition and biomarkers related to atherosclerosis, thereby providing insight into the mechanisms underlying the prevention of atherosclerosis progression by cilostazol and probucol. Trial registration number ClinicalTrials (NCT): NCT01031667 PMID:21226953

  3. Radiation Therapy in the Management of Malignant Melanoma.

    PubMed

    Mahadevan, Anand; Patel, Vivek L; Dagoglu, Nergiz

    2015-10-01

    The initial treatment for primary and locoregional melanoma is surgery. Systemic therapy, and more recently immune therapy, has been the mainstay in the adjuvant and particularly the metastatic setting. Aside from palliation, there is a limited role for definitive radiation therapy for melanoma. However, in the adjuvant setting, postoperative radiation can improve locoregional disease control, albeit with potential toxicity and limited survival benefit. Stereotactic radiosurgery plays a vital role in the treatment of limited brain and extracranial metastasis. PMID:26470898

  4. Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study.

    PubMed

    Lee, Katrina; Lenards, Nishele; Holson, Janice

    2016-01-01

    The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient׳s neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to the hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient׳s data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain. PMID:26235550

  5. High-dose-rate remote afterloaders for intraoperative radiation therapy.

    PubMed

    Gao, Song; Delclos, Marc E; Tomas, Lyvia C; Crane, Christopher H; Beddar, Sam

    2007-11-01

    Intraoperative radiation therapy (IORT) is a treatment option that directly irradiates a surgically exposed tumor or tumor bed while preventing radiation exposure of normal tissues. This article discusses the high-dose-rate intraoperative radiation therapy (HDR-IORT) technique by reviewing the roles of IORT team members, discussing needed equipment and supplies, describing quality assurance processes, explaining the HDR-IORT treatment delivery procedure, and reviewing the post-treatment phase. PMID:18050890

  6. Cancer and Radiation Therapy: Current Advances and Future Directions

    PubMed Central

    Baskar, Rajamanickam; Lee, Kuo Ann; Yeo, Richard; Yeoh, Kheng-Wei

    2012-01-01

    In recent years remarkable progress has been made towards the understanding of proposed hallmarks of cancer development and treatment. However with its increasing incidence, the clinical management of cancer continues to be a challenge for the 21st century. Treatment modalities comprise of radiation therapy, surgery, chemotherapy, immunotherapy and hormonal therapy. Radiation therapy remains an important component of cancer treatment with approximately 50% of all cancer patients receiving radiation therapy during their course of illness; it contributes towards 40% of curative treatment for cancer. The main goal of radiation therapy is to deprive cancer cells of their multiplication (cell division) potential. Celebrating a century of advances since Marie Curie won her second Nobel Prize for her research into radium, 2011 has been designated the Year of Radiation therapy in the UK. Over the last 100 years, ongoing advances in the techniques of radiation treatment and progress made in understanding the biology of cancer cell responses to radiation will endeavor to increase the survival and reduce treatment side effects for cancer patients. In this review, principles, application and advances in radiation therapy with their biological end points are discussed. PMID:22408567

  7. Stereotactic Body Radiation Therapy Versus Intensity-Modulated Radiation Therapy for Prostate Cancer: Comparison of Toxicity

    PubMed Central

    Yu, James B.; Cramer, Laura D.; Herrin, Jeph; Soulos, Pamela R.; Potosky, Arnold L.; Gross, Cary P.

    2014-01-01

    Purpose Stereotactic body radiation therapy (SBRT) is a technically demanding prostate cancer treatment that may be less expensive than intensity-modulated radiation therapy (IMRT). Because SBRT may deliver a greater biologic dose of radiation than IMRT, toxicity could be increased. Studies comparing treatment cost to the Medicare program and toxicity are needed. Methods We performed a retrospective study by using a national sample of Medicare beneficiaries age ≥ 66 years who received SBRT or IMRT as primary treatment for prostate cancer from 2008 to 2011. Each SBRT patient was matched to two IMRT patients with similar follow-up (6, 12, or 24 months). We calculated the cost of radiation therapy treatment to the Medicare program and toxicity as measured by Medicare claims; we used a random effects model to compare genitourinary (GU), GI, and other toxicity between matched patients. Results The study sample consisted of 1,335 SBRT patients matched to 2,670 IMRT patients. The mean treatment cost was $13,645 for SBRT versus $21,023 for IMRT. In the 6 months after treatment initiation, 15.6% of SBRT versus 12.6% of IMRT patients experienced GU toxicity (odds ratio [OR], 1.29; 95% CI, 1.05 to 1.53; P = .009). At 24 months after treatment initiation, 43.9% of SBRT versus 36.3% of IMRT patients had GU toxicity (OR, 1.38; 95% CI, 1.12 to 1.63; P = .001). The increase in GU toxicity was due to claims indicative of urethritis, urinary incontinence, and/or obstruction. Conclusion Although SBRT was associated with lower treatment costs, there appears to be a greater rate of GU toxicity for patients undergoing SBRT compared with IMRT, and prospective correlation with randomized trials is needed. PMID:24616315

  8. Future directions in intraoperative radiation therapy.

    PubMed

    Merrick, Hollis W; Gunderson, Leonard L; Calvo, Felipe A

    2003-10-01

    It is difficult to establish the degree of effectiveness of IORT as a component of treatment in some of the malignancies currently being treated by IORT. Locally advanced pancreatic cancer is a typical example of a neoplasm for which it has been challenging to find effective advances in treatment. The survival time of patients who have this disease is limited to 9 to 12 months (median), with a 2-year survival rate of 10% to 20% following even the most effective chemoradiation. It is perhaps overly optimistic to expect that IORT will significantly enhance survival, because currently available systemic treatment options have not meaningfully affected either overall patient survival times or the rate of distant metastasis in either the adjuvant setting or for metastatic disease. It is encouraging, however, that Willett has reported five patients with 5-year survival times in the Massachusetts General Hospital IOERT series for unresectable pancreatic cancer (C.G. Willett, personal communication, 2002). Also encouraging is the report from the Medical College of Ohio of a 5-year rate of 33% in a small group of patients with resectable pancreatic cancers treated with single IORT doses (without EBRT or chemotherapy) as the sole adjuvant to surgical resection. At the same institution, during the same time period, the same group of surgeons observed that no patient with resectable pancreatic cancer survived longer than 13 months following surgical resection alone [7]. Exciting possibilities involve the use of IORT when treating early-stage malignant disease, as is detailed in the chapter on breast cancer. The use of [table: see text] IORT as adjuvant therapy seems to be associated with an extremely low incidence of in-breast local recurrence. Whether this is because of early stage of the disease or the adjuvant EBRT is not entirely clear at the time of this writing. (The results of ongoing randomized studies may not be powered sufficiently to resolve the question.) Because the local recurrence rate currently is extremely low (only one reported recurrence), however, this finding is promising. Also exciting is the use of IORT as the sole radiation [table: see text] treatment following limited excision of breast cancer. The results of the Lanciano and Milano trials (see chapter 12) are awaited with great interest. Equally exciting is the finding of meaningful survival of 20% to 40% of patients who have local or regionally recurrent cancers when IORT is used as a component of treatment together with EBRT, maximal resection, and chemotherapy, as indicated. Many of these patients still have excessive rates of both local and distant relapse, however, necessitating the rationale for well-controlled multi-institutional studies that involve alternate systemic therapies, radiation sensitizers, among other criteria. PMID:14989135

  9. Localized fibrous mesothelioma of pleura following external ionizing radiation therapy

    SciTech Connect

    Bilbey, J.H.; Mueller, N.L.M.; Miller, R.R.; Nelems, B.

    1988-12-01

    Carcinogenesis is a well-known complication of radiation exposure. Ionizing radiation also leads to an increased incidence of benign tumors. A 36-year-old woman had a localized fibrous mesothelioma of the pleura and an ipsilateral breast carcinoma 23 years after receiving external radiation therapy for treatment of a chest wall keloid.

  10. Scatter factors assessment in microbeam radiation therapy

    SciTech Connect

    Prezado, Y.; Martinez-Rovira, I.; Sanchez, M.

    2012-03-15

    Purpose: The success of the preclinical studies in Microbeam Radiation Therapy (MRT) paved the way to the clinical trials under preparation at the Biomedical Beamline of the European Synchrotron Radiation Facility. Within this framework, an accurate determination of the deposited dose is crucial. With that aim, the scatter factors, which translate the absolute dose measured in reference conditions (2 x 2 cm{sup 2} field size at 2 cm-depth in water) to peak doses, were assessed. Methods: Monte Carlo (MC) simulations were performed with two different widely used codes, PENELOPE and GEANT4, for the sake of safety. The scatter factors were obtained as the ratio of the doses that are deposited by a microbeam and by a field of reference size, at the reference depth. The calculated values were compared with the experimental data obtained by radiochromic (ISP HD-810) films and a PTW 34070 large area chamber. Results: The scatter factors for different microbeam field sizes assessed by the two MC codes were in agreement and reproduced the experimental data within uncertainty bars. Those correction factors were shown to be non-negligible for the future MRT clinical settings: an average 30% lower dose was deposited by a 50 {mu}m microbeam with respect to the reference conditions. Conclusions: For the first time, the scatter factors in MRT were systematically studied. They constitute an essential key to deposit accurate doses in the forthcoming clinical trials in MRT. The good agreement between the different calculations and the experimental data confirms the reliability of this challenging micrometric dose estimation.

  11. Radiation Therapy for Chloroma (Granulocytic Sarcoma)

    SciTech Connect

    Bakst, Richard; Wolden, Suzanne; Yahalom, Joachim

    2012-04-01

    Objectives: Chloroma (granulocytic sarcoma) is a rare, extramedullary tumor of immature myeloid cells related to acute nonlymphocytic leukemia or myelodysplastic syndrome. Radiation therapy (RT) is often used in the treatment of chloromas; however, modern studies of RT are lacking. We reviewed our experience to analyze treatment response, disease control, and toxicity associated with RT to develop treatment algorithm recommendations for patients with chloroma. Patients and Methods: Thirty-eight patients who underwent treatment for chloromas at our institution between February 1990 and June 2010 were identified and their medical records were reviewed and analyzed. Results: The majority of patients that presented with chloroma at the time of initial leukemia diagnosis (78%) have not received RT because it regressed after initial chemotherapy. Yet most patients that relapsed or remained with chloroma after chemotherapy are in the RT cohort (90%). Thirty-three courses of RT were administered to 22 patients. Radiation subsite breakdown was: 39% head and neck, 24% extremity, 9% spine, 9% brain, 6% genitourinary, 6% breast, 3% pelvis, and 3% genitourinary. Median dose was 20 (6-36) Gy. Kaplan-Meier estimates of progression-free survival and overall survival in the RT cohort were 39% and 43%, respectively, at 5 years. At a median follow-up of 11 months since RT, only 1 patient developed progressive disease at the irradiated site and 4 patients developed chloromas at other sites. RT was well tolerated without significant acute or late effects and provided symptom relief in 95% of cases. Conclusions: The majority of patients with chloromas were referred for RT when there was extramedullary progression, marrow relapse, or rapid symptom relief required. RT resulted in excellent local disease control and palliation of symptoms without significant toxicity. We recommend irradiating chloromas to at least 20 Gy, and propose 24 Gy in 12 fractions as an appropriate regimen.

  12. Compensating for heterogeneities in proton radiation therapy.

    PubMed

    Urie, M; Goitein, M; Wagner, M

    1984-05-01

    Our method for predicting, and compensating for, the effects of surface irregularities and tissue heterogeneities in proton radiation therapy was evaluated by comparing the predicted and measured dose distributions. Two heterogeneity configurations in a D-shaped water-filled phantom were handled in exactly the same way as patients. Target volumes were designated on thin-section CT scans, a single en face portal was defined, compensating boli were designed and made, and the dose distribution behind the phantom measured and compared with that intended. The compensation was accurate to within 1 mm for the phantom with a single air heterogeneity and to within 2.5 mm for the phantom with multiple bone and air heterogeneities. The bolus and phantom were misaligned by 3 mm and the dramatic change in the dose distribution demonstrated the need to address the problems of patient motion and imperfect immobilisation through compensator design. A philosophy of 'expanding' the bolus is described, and dose distributions measured with the 'expanded' boli indicate that target volume treatment can be assured within prespecified repositioning and motion uncertainties. The uncertainty in the alignment of bolus and heterogeneities leads to corresponding uncertainty in the penetration of the protons. Ranges within which they will stop are calculated and shown to encompass adequately the measured distributions in both the aligned and misaligned cases. PMID:6330772

  13. Geometric accuracy in radiation therapy: Dosimetric, imaging and economic considerations

    NASA Astrophysics Data System (ADS)

    Ploquin, Nicolas P.

    In 2007 in Canada, 159,900 men and women will be diagnosed with cancer. Radiation Therapy (RT) is the treatment of cancer by irradiating malignant tissue with ionizing radiation and it is used on up to 50% of all cancers. The objective of radiation therapy is to deliver a lethal dose of radiation to the tumour while sparing the surrounding healthy tissues and organs at risks (OARs). Thus, the accuracy with which the radiation therapy process must be carried out is critical. The presence of setup errors and uncertainties throughout the RT process impacts the dose received by the tumour and OARs and can compromise the outcome for the patient. This thesis focuses on the study of the limiting geometrical accuracy imposed by factors present in radiation therapy process (such as setup errors and uncertainties or the spatial resolution of the imaging systems that we use) and its consequences for the patient. The consequences are quantified through the use of a physical outcome surrogate, the Equivalent Uniform Dose (EUD), which numerically describes the dose distribution received by the target and normal structures surrounding it. A cost-outcome analysis is presented in which the incremental cost of radiation therapy is directly related to the patients outcome (using the EUD) for using various imaging modalities and correction protocols in Image Guided Adaptive Radiation Therapy (IGART).

  14. Dosimetric and Late Radiation Toxicity Comparison Between Iodine-125 Brachytherapy and Stereotactic Radiation Therapy for Juxtapapillary Choroidal Melanoma

    SciTech Connect

    Krema, Hatem

    2013-07-01

    Purpose: To compare the dose distributions and late radiation toxicities for {sup 125}I brachytherapy (IBT) and stereotactic radiation therapy (SRT) in the treatment of juxtapapillary choroidal melanoma. Methods: Ninety-four consecutive patients with juxtapapillary melanoma were reviewed: 30 have been treated with IBT and 64 with SRT. Iodine-125 brachytherapy cases were modeled with plaque simulator software for dosimetric analysis. The SRT dosimetric data were obtained from the Radionics XKnife RT3 software. Mean doses at predetermined intraocular points were calculated. Kaplan-Meier estimates determined the actuarial rates of late toxicities, and the log–rank test compared the estimates. Results: The median follow-up was 46 months in both cohorts. The 2 cohorts were balanced with respect to pretreatment clinical and tumor characteristics. Comparisons of radiation toxicity rates between the IBT and SRT cohorts yielded actuarial rates at 50 months for cataracts of 62% and 75% (P=.1), for neovascular glaucoma 8% and 47% (P=.002), for radiation retinopathy 59% and 89% (P=.0001), and for radiation papillopathy 39% and 74% (P=.003), respectively. Dosimetric comparisons between the IBT and SRT cohorts yielded mean doses of 12.8 and 14.1 Gy (P=.56) for the lens center, 17.6 and 19.7 Gy (P=.44) for the lens posterior pole, 13.9 and 10.8 Gy (P=.30) for the ciliary body, 61.9 and 69.7 Gy (P=.03) for optic disc center, and 48.9 and 60.1 Gy (P<.0001) for retina at 5-mm distance from tumor margin, respectively. Conclusions: Late radiation-induced toxicities were greater with SRT, which is secondary to the high-dose exposure inherent to the technique as compared with IBT. When technically feasible, IBT is preferred to treat juxtapapillary choroidal melanoma.

  15. [Lung cancer: Stereotactic body radiation therapy and surgery].

    PubMed

    Antoni, D; Srour, I; Mornex, F

    2015-10-01

    Stereotactic body radiation therapy for lung cancer is now well established for patients who are not eligible to surgery. These patients can benefit from a curative treatment, which is a new therapeutic indication. Protocols are effective and well tolerated even for the most fragile patients. Three randomized trials comparing stereotactic body radiation therapy and surgery failed due to poor accrual. However, taking into account the favourable available data, the choice of stereotactic body radiation therapy in first intention arises. The treatment decision has to be discussed in a multidisciplinary way, while considering the opinion of the patient, who must be clearly informed about the principle of both therapeutic options. PMID:26358983

  16. Proton minibeam radiation therapy: Experimental dosimetry evaluation

    SciTech Connect

    Peucelle, C.; Martínez-Rovira, I.; Prezado, Y.; Nauraye, C.; Patriarca, A.; Hierso, E.; Fournier-Bidoz, N.

    2015-12-15

    Purpose: Proton minibeam radiation therapy (pMBRT) is a new radiotherapy (RT) approach that allies the inherent physical advantages of protons with the normal tissue preservation observed when irradiated with submillimetric spatially fractionated beams. This dosimetry work aims at demonstrating the feasibility of the technical implementation of pMBRT. This has been performed at the Institut Curie - Proton Therapy Center in Orsay. Methods: Proton minibeams (400 and 700 μm-width) were generated by means of a brass multislit collimator. Center-to-center distances between consecutive beams of 3200 and 3500 μm, respectively, were employed. The (passive scattered) beam energy was 100 MeV corresponding to a range of 7.7 cm water equivalent. Absolute dosimetry was performed with a thimble ionization chamber (IBA CC13) in a water tank. Relative dosimetry was carried out irradiating radiochromic films interspersed in a IBA RW3 slab phantom. Depth dose curves and lateral profiles at different depths were evaluated. Peak-to-valley dose ratios (PVDR), beam widths, and output factors were also assessed as a function of depth. Results: A pattern of peaks and valleys was maintained in the transverse direction with PVDR values decreasing as a function of depth until 6.7 cm. From that depth, the transverse dose profiles became homogeneous due to multiple Coulomb scattering. Peak-to-valley dose ratio values extended from 8.2 ± 0.5 at the phantom surface to 1.08 ± 0.06 at the Bragg peak. This was the first time that dosimetry in such small proton field sizes was performed. Despite the challenge, a complete set of dosimetric data needed to guide the first biological experiments was achieved. Conclusions: pMBRT is a novel strategy in order to reduce the side effects of RT. This works provides the experimental proof of concept of this new RT method: clinical proton beams might allow depositing a (high) uniform dose in a brain tumor located in the center of the brain (7.5 cm depth, the worst scenario), while a spatial fractionation of the dose is retained in the normal tissues in the beam path, potentially leading to a gain in tissue sparing. This is the first complete experimental implementation of this promising technique. Biological experiments are needed in order to confirm the clinical potential of pMBRT.

  17. Advances in Radiation Therapy in Pediatric Neuro-oncology.

    PubMed

    Bindra, Ranjit S; Wolden, Suzanne L

    2016-03-01

    Radiation therapy remains a highly effective therapy for many pediatric central nervous system tumors. With more children achieving long-term survival after treatment for brain tumors, late-effects of radiation have become an important concern. In response to this problem, treatment protocols for a variety of pediatric central nervous system tumors have evolved to reduce radiation fields and doses when possible. Recent advances in radiation technology such as image guidance and proton therapy have led to a new era of precision treatment with significantly less exposure to healthy tissues. These developments along with the promise of molecular classification of tumors and targeted therapies point to an optimistic future for pediatric neuro-oncology. PMID:26271789

  18. Superficial Radiation Therapy for the Treatment of Nonmelanoma Skin Cancers.

    PubMed

    McGregor, Sean; Minni, John; Herold, David

    2015-12-01

    Superficial radiation therapy has become more widely available to dermatologists. With the advent of more portable machines, it has become more convenient for dermatology practices to employ in an office-based setting. The goal of this paper is to provide a deeper insight into the role of superficial radiation therapy in dermatology practice and to review the current literature surrounding its use in the treatment of both basal and squamous cell carcinomas. PMID:26705443

  19. Superficial Radiation Therapy for the Treatment of Nonmelanoma Skin Cancers

    PubMed Central

    Minni, John; Herold, David

    2015-01-01

    Superficial radiation therapy has become more widely available to dermatologists. With the advent of more portable machines, it has become more convenient for dermatology practices to employ in an office-based setting. The goal of this paper is to provide a deeper insight into the role of superficial radiation therapy in dermatology practice and to review the current literature surrounding its use in the treatment of both basal and squamous cell carcinomas. PMID:26705443

  20. Multidetector row computed tomography may accurately estimate plaque vulnerability: does MDCT accurately estimate plaque vulnerability? (Pro).

    PubMed

    Komatsu, Sei; Imai, Atsuko; Kodama, Kazuhisa

    2011-01-01

    Over the past decade, multidetector row computed tomography (MDCT) has become the most reliable and established of the noninvasive examination techniques for detecting coronary heart disease. Now MDCT is chasing intravascular ultrasound (IVUS) in terms of spatial resolution. Among the components of vulnerable plaque, MDCT may detect lipid-rich plaque, the lipid pool, and calcified spots using computed tomography number. Plaque components are detected by MDCT with high accuracy compared with IVUS and angioscopy when assessing vulnerable plaque. The TWINS study and TOGETHAR trial demonstrated that angioscopic loss of yellow color occurred independently of volumetric plaque change by statin therapy. These 2 studies showed that plaque stabilization and regression reflect independent processes mediated by different mechanisms and time course. Noncalcified plaque and/or low-density plaque was found to be the strongest predictor of cardiac events, regardless of lesion severity, and act as a potential marker of plaque vulnerability. MDCT may be an effective tool for early triage of patients with chest pain who have a normal ECG and cardiac enzymes in the emergency department. MDCT has the potential ability to analyze coronary plaque quantitatively and qualitatively if some problems are resolved. MDCT may become an essential tool for detecting and preventing coronary artery disease in the future. PMID:21532180

  1. Persistence of endometrial activity after radiation therapy for cervical carcinoma

    SciTech Connect

    Barnhill, D.; Heller, P.; Dames, J.; Hoskins, W.; Gallup, D.; Park, R.

    1985-12-01

    Radiation therapy is a proved treatment for cervical carcinoma; however, it destroys ovarian function and has been thought to ablate the endometrium. Estrogen replacement therapy is often prescribed for patients with cervical carcinoma after radiation therapy. A review of records of six teaching hospitals revealed 16 patients who had endometrial sampling for uterine bleeding after standard radiation therapy for cervical carcinoma. Fifteen patients underwent dilatation and curettage, and one patient underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy when a dilatation and curettage was unsuccessful. Six patients had fibrosis and inflammation of the endometrial cavity, seven had proliferative endometrium, one had cystic hyperplasia, one had atypical adenomatous hyperplasia, and one had adenocarcinoma. Although the number of patients who have an active endometrium after radiation therapy for cervical carcinoma is not known, this report demonstrates that proliferative endometrium may persist, and these patients may develop endometrial hyperplasia or adenocarcinoma. Studies have indicated that patients with normal endometrial glands have an increased risk of developing endometrial adenocarcinoma if they are treated with unopposed estrogen. Patients who have had radiation therapy for cervical carcinoma should be treated with estrogen and a progestational agent to avoid endometrial stimulation from unopposed estrogen therapy.

  2. Thyroid neoplasia following radiation therapy for Hodgkin's lymphoma

    SciTech Connect

    McHenry, C.; Jarosz, H.; Calandra, D.; McCall, A.; Lawrence, A.M.; Paloyan, E.

    1987-06-01

    The question of thyroid neoplasia following high-dose radiation treatment to the neck and mediastinum for malignant neoplasms such as Hodgkin's lymphoma in children and young adults has been raised recently. Five patients, 19 to 39 years old, were operated on for thyroid neoplasms that developed following cervical and mediastinal radiation therapy for Hodgkin's lymphoma. Three patients had papillary carcinomas and two had follicular adenomas. The latency period between radiation exposure and the diagnosis of thyroid neoplasm ranged from eight to 16 years. This limited series provided strong support for the recommendation that children and young adults who are to receive high-dose radiation therapy to the head, neck, and mediastinum should receive suppressive doses of thyroxine prior to radiation therapy in order to suppress thyrotropin (thyroid-stimulating hormone) and then be maintained on a regimen of suppression permanently.

  3. Can radiation therapy treatment planning system accurately predict surface doses in postmastectomy radiation therapy patients?

    SciTech Connect

    Wong, Sharon; Back, Michael; Tan, Poh Wee; Lee, Khai Mun; Baggarley, Shaun; Lu, Jaide Jay

    2012-07-01

    Skin doses have been an important factor in the dose prescription for breast radiotherapy. Recent advances in radiotherapy treatment techniques, such as intensity-modulated radiation therapy (IMRT) and new treatment schemes such as hypofractionated breast therapy have made the precise determination of the surface dose necessary. Detailed information of the dose at various depths of the skin is also critical in designing new treatment strategies. The purpose of this work was to assess the accuracy of surface dose calculation by a clinically used treatment planning system and those measured by thermoluminescence dosimeters (TLDs) in a customized chest wall phantom. This study involved the construction of a chest wall phantom for skin dose assessment. Seven TLDs were distributed throughout each right chest wall phantom to give adequate representation of measured radiation doses. Point doses from the CMS Xio Registered-Sign treatment planning system (TPS) were calculated for each relevant TLD positions and results correlated. There were no significant difference between measured absorbed dose by TLD and calculated doses by the TPS (p > 0.05 (1-tailed). Dose accuracy of up to 2.21% was found. The deviations from the calculated absorbed doses were overall larger (3.4%) when wedges and bolus were used. 3D radiotherapy TPS is a useful and accurate tool to assess the accuracy of surface dose. Our studies have shown that radiation treatment accuracy expressed as a comparison between calculated doses (by TPS) and measured doses (by TLD dosimetry) can be accurately predicted for tangential treatment of the chest wall after mastectomy.

  4. Pelvic Normal Tissue Contouring Guidelines for Radiation Therapy: A Radiation Therapy Oncology Group Consensus Panel Atlas

    SciTech Connect

    Gay, Hiram A.; Barthold, H. Joseph; O'Meara, Elizabeth; Bosch, Walter R.; El Naqa, Issam; Al-Lozi, Rawan; Rosenthal, Seth A.; Lawton, Colleen; Lee, W. Robert; Sandler, Howard; Zietman, Anthony; Myerson, Robert; Dawson, Laura A.; Willett, Christopher; Kachnic, Lisa A.; Jhingran, Anuja; Portelance, Lorraine; Ryu, Janice; and others

    2012-07-01

    Purpose: To define a male and female pelvic normal tissue contouring atlas for Radiation Therapy Oncology Group (RTOG) trials. Methods and Materials: One male pelvis computed tomography (CT) data set and one female pelvis CT data set were shared via the Image-Guided Therapy QA Center. A total of 16 radiation oncologists participated. The following organs at risk were contoured in both CT sets: anus, anorectum, rectum (gastrointestinal and genitourinary definitions), bowel NOS (not otherwise specified), small bowel, large bowel, and proximal femurs. The following were contoured in the male set only: bladder, prostate, seminal vesicles, and penile bulb. The following were contoured in the female set only: uterus, cervix, and ovaries. A computer program used the binomial distribution to generate 95% group consensus contours. These contours and definitions were then reviewed by the group and modified. Results: The panel achieved consensus definitions for pelvic normal tissue contouring in RTOG trials with these standardized names: Rectum, AnoRectum, SmallBowel, Colon, BowelBag, Bladder, UteroCervix, Adnexa{sub R}, Adnexa{sub L}, Prostate, SeminalVesc, PenileBulb, Femur{sub R}, and Femur{sub L}. Two additional normal structures whose purpose is to serve as targets in anal and rectal cancer were defined: AnoRectumSig and Mesorectum. Detailed target volume contouring guidelines and images are discussed. Conclusions: Consensus guidelines for pelvic normal tissue contouring were reached and are available as a CT image atlas on the RTOG Web site. This will allow uniformity in defining normal tissues for clinical trials delivering pelvic radiation and will facilitate future normal tissue complication research.

  5. Once-Daily Radiation Therapy for Inflammatory Breast Cancer

    SciTech Connect

    Brown, Lindsay; Harmsen, William; Blanchard, Miran; Goetz, Matthew; Jakub, James; Mutter, Robert; Petersen, Ivy; Rooney, Jessica; Stauder, Michael; Yan, Elizabeth; Laack, Nadia

    2014-08-01

    Purpose: Inflammatory breast cancer (IBC) is a rare and aggressive breast cancer variant treated with multimodality therapy. A variety of approaches intended to escalate the intensity and efficacy of radiation therapy have been reported, including twice-daily radiation therapy, dose escalation, and aggressive use of bolus. Herein, we examine our outcomes for patients treated with once-daily radiation therapy with aggressive bolus utilization, focusing on treatment technique. Methods and Materials: A retrospective review of patients with nonmetastatic IBC treated from January 1, 2000, through December 31, 2010, was performed. Locoregional control (LRC), disease-free survival (DFS), overall survival (OS) and predictors thereof were assessed. Results: Fifty-two women with IBC were identified, 49 (94%) of whom were treated with neoadjuvant chemotherapy. All underwent mastectomy followed by adjuvant radiation therapy. Radiation was delivered in once-daily fractions of 1.8 to 2.25 Gy (median, 2 Gy). Patients were typically treated with daily 1-cm bolus throughout treatment, and 33 (63%) received a subsequent boost to the mastectomy scar. Five-year Kaplan Meier survival estimates for LRC, DFS, and OS were 81%, 56%, and 64%, respectively. Locoregional recurrence was associated with poorer OS (P<.001; hazard ratio [HR], 4.1). Extracapsular extension was associated with worse LRC (P=.02), DFS (P=.007), and OS (P=.002). Age greater than 50 years was associated with better DFS (P=.03). Pathologic complete response was associated with a trend toward improved LRC (P=.06). Conclusions: Once-daily radiation therapy with aggressive use of bolus for IBC results in outcomes consistent with previous reports using various intensified radiation therapy regimens. LRC remains a challenge despite modern systemic therapy. Extracapsular extension, age ≤50 years, and lack of complete response to chemotherapy appear to be associated with worse outcomes. Novel strategies are needed in IBC, particularly among these subsets of patients.

  6. An Investigation of Vascular Strategies to Augment Radiation Therapy

    NASA Astrophysics Data System (ADS)

    El Kaffas, Ahmed Nagy

    Radiation therapy is administered to more than 50% of patients diagnosed with cancer. Mechanisms of interaction between radiation and tumour cells are relatively well understood on a molecular level, but much remains uncertain regarding how radiation interacts with the tumour as a whole. Recent studies have suggested that tumour response to radiation may in fact be regulated by endothelial cell response, consequently stressing the role of tumour blood vessels in radiation treatment response. As a result, various treatment regimens have been proposed to strategically combine radiation with vascular targeting agents. A great deal of effort has been aimed towards developing efficient vascular targeting agents. Nonetheless, no optimal method has yet been devised to strategically deliver such agents. Recent evidence suggesting that these drugs may "normalize" tumour blood vessels and enhance radiosensitivity, is supporting experiments where anti-angiogenic drugs are combined with cytotoxic therapies such as radiotherapy. In contrast, ultrasound-stimulated microbubbles have recently been demonstrated to enhance radiation therapy by biophysically interacting with endothelial cells. When combined with single radiation doses, these microbubbles are believed to cause localized vascular destruction followed by tumour cell death. Finally, a new form of 'pro-angiogenics' has also been demonstrated to induce a therapeutic tumour response. The overall aim of this thesis is to study the role of tumour blood vessels in treatment responses to single-dose radiation therapy and to investigate radiation-based vascular targeting strategies. Using pharmacological and biophysical agents, blood vessels were altered to determine how they influence tumour cell death, clonogenicity, and tumour growth, and to study how these may be optimally combined with radiation. Three-dimensional high-frequency power Doppler ultrasound was used throughout these studies to investigate vascular response to therapy.

  7. Cranial Radiation Therapy and Damage to Hippocampal Neurogenesis

    ERIC Educational Resources Information Center

    Monje, Michelle

    2008-01-01

    Cranial radiation therapy is associated with a progressive decline in cognitive function, prominently memory function. Impairment of hippocampal neurogenesis is thought to be an important mechanism underlying this cognitive decline. Recent work has elucidated the mechanisms of radiation-induced failure of neurogenesis. Potential therapeutic…

  8. Cranial Radiation Therapy and Damage to Hippocampal Neurogenesis

    ERIC Educational Resources Information Center

    Monje, Michelle

    2008-01-01

    Cranial radiation therapy is associated with a progressive decline in cognitive function, prominently memory function. Impairment of hippocampal neurogenesis is thought to be an important mechanism underlying this cognitive decline. Recent work has elucidated the mechanisms of radiation-induced failure of neurogenesis. Potential therapeutic

  9. 21 CFR 892.5050 - Medical charged-particle radiation therapy system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system...) intended for use in radiation therapy. This generic type of device may include signal analysis and...

  10. 21 CFR 892.5050 - Medical charged-particle radiation therapy system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system...) intended for use in radiation therapy. This generic type of device may include signal analysis and...

  11. 21 CFR 892.5050 - Medical charged-particle radiation therapy system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system...) intended for use in radiation therapy. This generic type of device may include signal analysis and...

  12. 21 CFR 892.5050 - Medical charged-particle radiation therapy system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) intended for use in radiation therapy. This generic type of device may include signal analysis and display... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy...

  13. A pharmacoeconomic analysis of topical therapies for patients with mild-to-moderate stable plaque psoriasis: a US study.

    PubMed

    Marchetti, A; LaPensee, K; An, P

    1998-01-01

    Psoriasis is a persistent skin disorder characterized by abnormal keratinocyte differentiation, keratinocyte hyperproliferation, and increased expression of inflammatory markers at the cellular level, leading to erythema, induration, and scaling of the skin. Depending on the severity of the disease, annual outpatient costs range from $1400 to $6600 per patient, totaling $3.2 billion each year in the United States. Because the disease is persistent and progressive, patients receiving a diagnosis of psoriasis early in life can expect to require lifelong care, which translates into lifelong expense. Treatments include topical formulations, systemic therapies, phototherapies, and combination therapies. Of these, topical agents are the first-line treatments, including fluocinonide and other steroids, calcipotriene, and tazarotene, a once-daily retinoid. To establish the relative cost-effectiveness of these drugs (fluocinonide, calcipotriene, and tazarotene), we conducted a pharmacoeconomic study from the perspective of a third-party payer, using a decision-analytic model validated by clinical experts. Data were drawn from a meta-analysis of the contemporary medical literature. Clinical success, clearing, and relapse rates determined the probabilities for therapeutic outcomes and the number of anticipated disease-free days for each study comparator. Costs for physician visits, drug acquisition, laboratory testing, and adverse-events management were added to each branch of the decision tree and multiplied by the appropriate probabilities to establish the expected cost of treatment, stratified by the primary treatment choice. Cost-effectiveness was expressed as the total expected cost of achieving a disease-free day. Tazarotene 0.1% was 16.74% more cost-effective than tazarotene 0.05%, 85.46% more cost-effective than fluocinonide, and 143.75% more cost-effective than calcipotriene. The expected cost of achieving a disease-free day was $49.46 for tazarotene 0.1%, $57.74 for tazarotene 0.05%, $91.73 for fluocinonide, and $120.56 for calcipotriene. Treatment with tazarotene offers an opportunity to reduce the cost of care for patients with mild-to-moderate psoriasis and enhance patient satisfaction by gaining more disease-free days. PMID:9737842

  14. Effects of UV radiation on plaque formation of Herpes Simplex Type 1 on C3H/10T/sub 1/2/ monolayers

    SciTech Connect

    Montes, J.G.

    1983-01-01

    HSV-1 plaque-forming ability and plaque sizes were assayed on C3H/10T/sub 1/2/ monolayers as a function of the following variables: (1) pretreatment dose with UV light at different times before inoculation; (2) pretreatment dose with cycloheximide 24 hours before inoculation; and (3) population density of monolayers at time of inoculation. Irradiated virus exhibited smaller plaques than in controls (small plaque effect, SPE). The capacity of the cells was found to increase substantially with pretreatment with UV light or cycloheximide (capacity enhancement effect, CE); these agents also produced larger plaques than on controls (the large plaque effect, LPE). No significant UV light-enhanced reactivation (ER) was observed; thus, UV light-induced ER and LPE were not correlated in this system. Pretreatment with cycloheximide, however, seemed to produce a moderate level of ER.

  15. Radiation Therapy for Neovascular Age-related Macular Degeneration

    SciTech Connect

    Kishan, Amar U.; Modjtahedi, Bobeck S.; Morse, Lawrence S.; Lee, Percy

    2013-03-01

    In the enormity of the public health burden imposed by age-related macular degeneration (ARMD), much effort has been directed toward identifying effective and efficient treatments. Currently, anti-vascular endothelial growth factor (VEGF) injections have demonstrated considerably efficacy in treating neovascular ARMD, but patients require frequent treatment to fully benefit. Here, we review the rationale and evidence for radiation therapy of ARMD. The results of early photon external beam radiation therapy are included to provide a framework for the sequential discussion of evidence for the usage of stereotactic radiation therapy, proton therapy, and brachytherapy. The evidence suggests that these 3 modern modalities can provide a dose-dependent benefit in the treatment of ARMD. Most importantly, preliminary data suggest that all 3 can be used in conjunction with anti-VEGF therapeutics, thereby reducing the frequency of anti-VEGF injections required to maintain visual acuity.

  16. The Role of Radiation Therapy in Pancreas Cancer

    PubMed Central

    2009-01-01

    The role of radiation therapy in pancreatic cancer continues to be investigated. Its use in the adjuvant setting remains controversial. Its use is more generally accepted in borderline resectable disease, but prospective data are sparse. Randomized trials have yielded conflicting data in locally advanced disease. Radiation techniques have improved over time, such that findings in older trials are not necessarily applicable in modern practice. This article reviews the role of radiation in resectable, borderline resectable, and unresectable pancreatic cancer. PMID:19343134

  17. Magnetic resonance imaging of juxtapapillary plaques in cadaver eyes.

    PubMed Central

    Williams, D F; Mieler, W F; Jaffe, G J; Robertson, D M; Hendrix, L

    1990-01-01

    Adequate treatment of juxtapapillary melanomas with episcleral plaque brachytherapy using lower energy radiation sources may be difficult because of uncertainties regarding the relationship of the plaque to the optic nerve and tumour base. We obtained magnetic resonance images of a dummy plaque placed in a juxtapapillary location in cadaver specimens. Although it is possible to place a plaque in close association with the optic nerve sheath, a tissue barrier exists which may prevent actual contact between the plaque and nerve. Posterior tilting of the plaque may also occur. Because of these uncertainties regarding plaque placement, juxtapapillary melanomas should be considered a distinct subgroup when evaluating the efficacy of radioactive plaque brachytherapy in the treatment of choroidal melanoma. Images PMID:2306444

  18. New technologies in radiation therapy: ensuring patient safety, radiation safety and regulatory issues in radiation oncology.

    PubMed

    Amols, Howard I

    2008-11-01

    New technologies such as intensity modulated and image guided radiation therapy, computer controlled linear accelerators, record and verify systems, electronic charts, and digital imaging have revolutionized radiation therapy over the past 10-15 y. Quality assurance (QA) as historically practiced and as recommended in reports such as American Association of Physicists in Medicine Task Groups 40 and 53 needs to be updated to address the increasing complexity and computerization of radiotherapy equipment, and the increased quantity of data defining a treatment plan and treatment delivery. While new technology has reduced the probability of many types of medical events, seeing new types of errors caused by improper use of new technology, communication failures between computers, corrupted or erroneous computer data files, and "software bugs" are now being seen. The increased use of computed tomography, magnetic resonance, and positron emission tomography imaging has become routine for many types of radiotherapy treatment planning, and QA for imaging modalities is beyond the expertise of most radiotherapy physicists. Errors in radiotherapy rarely result solely from hardware failures. More commonly they are a combination of computer and human errors. The increased use of radiosurgery, hypofractionation, more complex intensity modulated treatment plans, image guided radiation therapy, and increasing financial pressures to treat more patients in less time will continue to fuel this reliance on high technology and complex computer software. Clinical practitioners and regulatory agencies are beginning to realize that QA for new technologies is a major challenge and poses dangers different in nature than what are historically familiar. PMID:18849700

  19. Management of Dysphonia After Radiation Therapy.

    PubMed

    Villari, Craig R; Courey, Mark S

    2015-08-01

    Radiation-induced dysphonia can develop after radiation for primary laryngeal cancer or when the larynx is in the radiation field for nonlaryngeal malignancy. The effects are dose dependent and lead to variable degrees of dysphonia in both short- and long-term follow-up. Rehabilitation of the irradiated larynx can prove frustrating but can be facilitated through behavioral, pharmacologic, or surgical interventions. PMID:26092762

  20. Primary radiation therapy for early breast cancer: the experience at the joint center for radiation therapy

    SciTech Connect

    Harris, J.R.; Botnick, L.; Bloomer, W.D.; Chaffey, J.T.; Hellman, S.

    1981-11-01

    The results of primary radiation therapy in 176 consecutive patients with clinical State I and II carcinoma of the breast were reviewed. Median follow-up time was 47 months. The overall breast relapse rate was 7%. Patients undergoing interstitial implantation had a significantly lower breast relapse rate (1%) than patients not undergoing implantation (11%). Breast relapse was more common in patients undergoing incisional or needle biopsy (17%), compared to patients treated after excisional biopsy (5%). In patients undergoing excisional biopsy, but not interstitial implantation, breast relapse was related to external beam dose. Twelve percent of the patients who received less than 1600 ret dose relapsed in the breast, compared to none of the 19 patients who received more than 1700 ret dose. These results imply that supplemental irradiation to the primary tumor area is required following excisional biopsy of a primary breast cancer when 4500-5000 rad is delivered to the entire breast.

  1. Prototype demonstration of radiation therapy planning code system

    SciTech Connect

    Little, R.C.; Adams, K.J.; Estes, G.P.; Hughes, L.S. III; Waters, L.S.

    1996-09-01

    This is the final report of a one-year, Laboratory-Directed Research and Development project at the Los Alamos National Laboratory (LANL). Radiation therapy planning is the process by which a radiation oncologist plans a treatment protocol for a patient preparing to undergo radiation therapy. The objective is to develop a protocol that delivers sufficient radiation dose to the entire tumor volume, while minimizing dose to healthy tissue. Radiation therapy planning, as currently practiced in the field, suffers from inaccuracies made in modeling patient anatomy and radiation transport. This project investigated the ability to automatically model patient-specific, three-dimensional (3-D) geometries in advanced Los Alamos radiation transport codes (such as MCNP), and to efficiently generate accurate radiation dose profiles in these geometries via sophisticated physics modeling. Modem scientific visualization techniques were utilized. The long-term goal is that such a system could be used by a non-expert in a distributed computing environment to help plan the treatment protocol for any candidate radiation source. The improved accuracy offered by such a system promises increased efficacy and reduced costs for this important aspect of health care.

  2. Rationale for combining surgery and radiation therapy

    SciTech Connect

    Suit, H.D.; Todoroki, T.

    1985-05-01

    The combination of radiation and surgery is being employed increasingly in preference to radical surgery alone or high radiation dose alone in the treatment of malignant epithelial and mesenchymal neoplasms. The basis for this interest is that the scope of the surgery and/or the radiation dose level are less than if either were employed alone. A reduction in treatment related morbidity, improved cosmetic and functional status, and in some instances a lower local failure rate may be achieved by this approach. The rationale for combining radiation and surgery is that radiation at moderate dose levels is effective in the eradication of microscopic extensions of tumor beyond the clearly obvious mass while the surgery (usually more conservative) removes the principal mass.

  3. Radiation therapy of primary vaginal carcinoma

    SciTech Connect

    Nori, D.; Hilaris, B.S.; Stanimir, G.; Lewis, J.L. Jr.

    1983-10-01

    Primary carcinoma of the vagina is rare, constituting only 1 to 2% of all neoplasms arising in the female genital tract. From 1950-1974, 36 patients with carcinoma of the vagina were treated with radiation at Memorial Sloan-Kettering Cancer Center (MSKCC); 35 (96%) had epidermoid carcinoma and one patient (4%) had adenocarcinoma. These patients were staged according to FIGO. Fourteen patients (39%) were Stage I; six patients (17%) were Stage II; three patients (8%) were Stage III; and 13 patients (36%) were Stage IV. Nine patients (25%) were treated with external radiation and interstitial implant; seven patients (20%) were treated with interstitial implant alone; nine patients (25%) were treated with external radiation alone and 11 patients (30%) with external radiation and intracavitary radiation. The five year NED survival was 71% in Stage I, 66% in Stage II, 33% in Stage III and 0% in Stage IV. This paper discusses radiotherapy management of primary carcinoma of the vagina.

  4. Application of Histogram Analysis in Radiation Therapy (HART) in Intensity Modulation Radiation Therapy (IMRT) Treatments

    NASA Astrophysics Data System (ADS)

    Pyakuryal, Anil

    2009-03-01

    A carcinoma is a malignant cancer that emerges from epithelial cells in structures through out the body.It invades the critical organs, could metastasize or spread to lymph nodes.IMRT is an advanced mode of radiation therapy treatment for cancer. It delivers more conformal doses to malignant tumors sparing the critical organs by modulating the intensity of radiation beam.An automated software, HART (S. Jang et al.,2008,Med Phys 35,p.2812) was used for efficient analysis of dose volume histograms (DVH) for multiple targets and critical organs in four IMRT treatment plans for each patient. IMRT data for ten head and neck cancer patients were exported as AAPM/RTOG format files from a commercial treatment planning system at Northwestern Memorial Hospital (NMH).HART extracted DVH statistics were used to evaluate plan indices and to analyze dose tolerance of critical structures at prescription dose (PD) for each patient. Mean plan indices (n=10) were found to be in good agreement with published results for Linac based plans. The least irradiated volume at tolerance dose (TD50) was observed for brainstem and the highest volume for larynx in SIB treatment techniques. Thus HART, an open source platform, has extensive clinical implications in IMRT treatments.

  5. SYSTEMATIC REVIEW OF HYPOFRACTIONATED RADIATION THERAPY FOR PROSTATE CANCER

    PubMed Central

    Zaorsky, Nicholas G; Ohri, Nitin; Showalter, Timothy N; Dicker, Adam P; Den, Robert B

    2013-01-01

    Prostate cancer is the second most prevalent solid tumor diagnosed in men in the United States and Western Europe. Conventionally fractionated external beam radiation therapy (1.8-2.0 Gy/fraction) is an established treatment modality for men in all disease risk groups. Emerging evidence from experimental and clinical studies suggests that the α/β ratio for prostate cancer may be as low as 1.5 Gy, which has prompted investigators around the world to explore moderately hypofractionated radiation therapy (2.1-3.5 Gy/fraction). We review the impetus behind moderate hypofractionation and the current clinical evidence supporting moderate hypofractionated radiation therapy for prostate cancer. Although hypofractionated radiation therapy has many theoretical advantages, there is no clear evidence from prospective, randomized, controlled trials showing that hypofractionated schedules have improved outcomes or lower toxicity than conventionally fractionated regimens. Currently, hypofractionated schedules should only be used in the context of clinical trials. High dose rate brachytherapy and stereotactic body radiation therapy (fraction size 3.5 Gy and greater) are alternative approaches to hypofractionation, but are beyond the scope of this report. PMID:23453861

  6. Three-dimensional conformal radiation therapy in the liver: MRI findings along a time continuum.

    PubMed

    Lall, Chandana; Bhargava, Puneet; Sandrasegaran, Kumaresan; Shanbhogue, Alampady K; Ramsinghani, Nilam; Koh, Young Whan; Choi, Jin Young; Choi, Joon-Il

    2015-01-01

    Recent development of 3-dimensional conformal radiation therapies provides a concentrated radiation dose to the tumor. To achieve this goal, a complex design of multiple narrow beamlets is used to shape the radiation exposure to conform to the shape of the tumor. Imaging findings after novel radiation therapy techniques differ from those of conventional radiation therapy. This article discusses changes in the liver parenchyma and tumor after conformal radiation therapy focusing on magnetic resonance imaging. PMID:25700224

  7. Quantitative analysis of tomotherapy, linear-accelerator-based 3D conformal radiation therapy, intensity-modulated radiation therapy, and 4D conformal radiation therapy

    NASA Astrophysics Data System (ADS)

    Cho, Jae-Hwan; Lee, Hae-Kag; Dong, Kyung-Rae; Chung, Woon-Kwan; Lee, Jong-Woong; Park, Hoon-Hee

    2012-04-01

    This study quantified, evaluated and analyzed the radiation dose to which tumors and normal tissues were exposed in 3D conformal radiation therapy (CRT), intensity-modulated radiation therapy (IMRT) and tomotherapy by using a dose volume histogram (DVH) that represented the volume dose and the dose distribution of anatomical structures in the evaluation of treatment planning. Furthermore, a comparison was made for the dose to the gross tumor volume (GTV) and the planning target volume (PTV) of organ to be treated based on the change in field size for three- and four-dimensional computed tomography (3D-CT and 4D-CT) (gating based) and in the histogram with a view to proving the usefulness of 4D-CT therapy, which corresponds to respiration-gated radiation therapy. According to the study results, a comparison of 3D CRT, IMRT with a linear accelerator (LINAC), and tomotherapy demonstrated that the GTV of the cranium was higher for tomotherapy than for 3D CRT and IMRT with a LINAC by 5.2% and 4.6%, respectively. The GTV of the neck was higher for tomotherapy than for 3D CRT and IMRT with a LINAC by 6.5% and 2.0%, respectively. The GTV of the pelvis was higher for tomotherapy than for 3D CRT and IMRT with a LINAC by 8.6% and 3.7%, respectively. When the comparison was made for the 3D-CT and the 4D-CT (gating based) treatment equipment, the GTV and the PTV became smaller for 4D-CT treatment planning than for 3D-CT, which could reduce the area in which normal tissues in the surroundings are exposed to an unnecessary radiation dose. In addition, when 4D-CT treatment planning (gating based) was used, the radiation dose could be concentrated on the GTV, CTV or PTV, which meant that the treatment area exceeded that when 3D-CT's treatment planning was used. Moreover, the radiation dose on nearby normal tissues could be reduced. When 4D-CT treatment planning (gating based) was utilized, unnecessary areas that were exposed to a radiation dose could be reduced more than they could when 3D-CT treatment planning was utilized. This helped concentrate the radiation dose on the treatment area and, at the same time, reduce the radiation dose to which nearby normal tissues were exposed.

  8. Complications following radiation therapy to the head

    SciTech Connect

    Helpin, M.L.; Krejmas, N.L.; Krolls, S.O.

    1986-03-01

    A case is presented in which a child who received therapeutic radiation as part of his treatment regimen for rhabdomyosarcoma of the infratemporal and parapharyngeal region demonstrated undesirable sequelae in the dentition and the mandible.

  9. Intensity-Modulated Radiation Therapy (IMRT)

    MedlinePlus

    ... collaboration with the physician. top of page What equipment is used? A medical linear accelerator (LINAC) generates ... more information. top of page Who operates the equipment? The radiation therapist operates the equipment from a ...

  10. Influence of radiation therapy on oral Candida albicans colonization: a quantitative assessment

    SciTech Connect

    Rossie, K.M.; Taylor, J.; Beck, F.M.; Hodgson, S.E.; Blozis, G.G.

    1987-12-01

    An increase in quantity of oral Candida albicans was documented in patients receiving head and neck radiation therapy during and after therapy, as assessed by an oral-rinse culturing technique. The amount of the increase was greater in denture wearers and directly related to increasing radiation dose and increasing volume of parotid gland included in the radiation portal. A significant number of patients who did not carry C. albicans prior to radiation therapy developed positive cultures by 1 month after radiation therapy. The percentage of patients receiving head and neck radiation therapy who carried C. albicans prior to radiation therapy did not differ significantly from matched dental patient controls.

  11. Considering the role of radiation therapy for gastrointestinal stromal tumor

    PubMed Central

    Corbin, Kimberly S; Kindler, Hedy L; Liauw, Stanley L

    2014-01-01

    Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors arising in the gastrointestinal tract. Over the last decade, the management and prognosis of GISTs has changed dramatically with molecular characterization of the c-kit mutation and the adoption of targeted systemic therapy. Currently, the standard of care for resectable tumors is surgery, followed by adjuvant imatinib for tumors at high risk for recurrence. Inoperable or metastatic tumors are treated primarily with imatinib. Despite excellent initial response rates, resistance to targeted therapy has emerged as a common clinical problem, with relatively few therapeutic solutions. While the treatment of GISTs does not commonly include radiotherapy, radiation therapy could be a valuable contributing modality. Several case reports indicate that radiation can control locally progressive, drug-resistant disease. Further study is necessary to define whether radiation could potentially prevent or delay the onset of drug resistance, or improve outcomes when given in combination with imatinib. PMID:24872712

  12. Determinants of job satisfaction among radiation therapy faculty.

    PubMed

    Swafford, Larry G; Legg, Jeffrey S

    2009-01-01

    Job satisfaction is one of the most significant predictors of employee retention in a variety of occupational settings, including health care and education. A national survey of radiation therapy educators (n = 90) has indicated that respondents are not satisfied with their jobs based on data collected using the Minnesota Satisfaction Questionnaire (MSQ). To predict the factors associated with job satisfaction or dissatisfaction, the authors used a nine-item questionnaire derived from the MSQ. Educators were grouped according to their job satisfaction scores, and multiple discriminant analysis was used to determine which factors were predictive of satisfaction among groups of educators. Statistical results indicate that ability utilization, institutional support, compensation, personnel, and job characteristics were key determinants of job satisfaction among radiation therapy educators. These results may better inform faculty and administration of important factors that can promote job satisfaction and retain faculty in radiation therapy education programs. PMID:19753428

  13. Enhanced radiation therapy with multilayer microdisks containing radiosensitizing gold nanoparticles.

    PubMed

    Zhang, Peipei; Qiao, Yong; Xia, Junfei; Guan, Jingjiao; Ma, Liyuan; Su, Ming

    2015-03-01

    A challenge of X-ray radiation therapy is that high dose X-rays at therapeutic conditions damage normal cells. This paper describes the use of gold nanoparticle-loaded multilayer microdisks to enhance X-ray radiation therapy, where each microdisk contains over 10(5) radiosensitizing nanoparticles. The microdisks are attached on cell membranes through electrostatic interaction. Upon X-ray irradiation, more photoelectrons and Auger electrons are generated in the vicinity of the nanoparticles, which cause water ionization and lead to the formation of free radicals that damage the DNA of adjacent cancer cells. By attaching a large amount of gold nanoparticles on cancer cells, the total X-ray dose required for DNA damage and cell killing can be reduced. Due to their controllable structure and composition, multilayer microdisks can be a viable choice for enhanced radiation therapy with nanoparticles. PMID:25679345

  14. Imaging and Data Acquisition in Clinical Trials for Radiation Therapy.

    PubMed

    FitzGerald, Thomas J; Bishop-Jodoin, Maryann; Followill, David S; Galvin, James; Knopp, Michael V; Michalski, Jeff M; Rosen, Mark A; Bradley, Jeffrey D; Shankar, Lalitha K; Laurie, Fran; Cicchetti, M Giulia; Moni, Janaki; Coleman, C Norman; Deye, James A; Capala, Jacek; Vikram, Bhadrasain

    2016-02-01

    Cancer treatment evolves through oncology clinical trials. Cancer trials are multimodal and complex. Assuring high-quality data are available to answer not only study objectives but also questions not anticipated at study initiation is the role of quality assurance. The National Cancer Institute reorganized its cancer clinical trials program in 2014. The National Clinical Trials Network (NCTN) was formed and within it was established a Diagnostic Imaging and Radiation Therapy Quality Assurance Organization. This organization is Imaging and Radiation Oncology Core, the Imaging and Radiation Oncology Core Group, consisting of 6 quality assurance centers that provide imaging and radiation therapy quality assurance for the NCTN. Sophisticated imaging is used for cancer diagnosis, treatment, and management as well as for image-driven technologies to plan and execute radiation treatment. Integration of imaging and radiation oncology data acquisition, review, management, and archive strategies are essential for trial compliance and future research. Lessons learned from previous trials are and provide evidence to support diagnostic imaging and radiation therapy data acquisition in NCTN trials. PMID:26853346

  15. The physical basis and future of radiation therapy

    PubMed Central

    Bortfeld, T; Jeraj, R

    2011-01-01

    The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more compact and cheaper technologies. Bigger challenges lie ahead of physicists in radiation therapy beyond the dose localisation problem, for example in the areas of biological target definition, improved modelling for normal tissues and tumours, advanced multicriteria and robust optimisation, and continuous incorporation of advanced technologies such as molecular imaging. The success of physics in radiation therapy has been based on the continued “fuelling” of the field with new discoveries and inventions from physics research. A key to the success has been the application of the rigorous scientific method. In spite of the importance of physics research for radiation therapy, too few physicists are currently involved in cutting-edge research. The increased emphasis on more “professionalism” in medical physics will tip the situation even more off balance. To prevent this from happening, we argue that medical physics needs more research positions, and more and better academic programmes. Only with more emphasis on medical physics research will the future of radiation therapy and other physics-related medical specialties look as bright as the past, and medical physics will maintain a status as one of the most exciting fields of applied physics. PMID:21606068

  16. Radiation beam therapy evolution: From X-rays to hadrons

    SciTech Connect

    Khoroshkov, V. S.

    2006-10-15

    The history of external radiation beam therapy (radiotherapy)-in particular, proton therapy (PT)-is brietly outlined. Two possible strategies in increasing the efficacy of radiotherapy are considered. The radiotherapy methods and techniques are brietly described. The possibilities of PT in providing effective treatment and the main achievements are demonstrated. The state of the art in the PT development involving the active creation of large clinical PT centers since 1990 is analyzed.

  17. Pioneer F Plaque Location

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Pioneer F spacecraft, destined to be the first man made object to escape from the solar system into interstellar space, carries this pictorial plaque. It is designed to show scientifically educated inhabitants of some other star system, who might intercept it millions of years from now, when Pioneer was launched, from where, and by what kind of beings. (Hopefully, any aliens reading the plaque will not use this knowledge to immediately invade Earth.) The design is etched into a 6 inch by 9 inch gold-anodized aluminum plate, attached to the spacecraft's attenna support struts in a position to help shield it from erosion by interstellar dust. The radiating lines at left represents the positions of 14 pulsars, a cosmic source of radio energy, arranged to indicate our sun as the home star of our civilization. The '1-' symbols at the ends of the lines are binary numbers that represent the frequencies of these pulsars at the time of launch of Pioneer F relative of that to the hydrogen atom shown at the upper left with a '1' unity symbol. The hydrogen atom is thus used as a 'universal clock,' and the regular decrease in the frequencies of the pulsars will enable another civilization to determine the time that has elapsed since Pioneer F was launched. The hydrogen is also used as a 'universal yardstick' for sizing the human figures and outline of the spacecraft shown on the right. The hydrogen wavelength, about 8 inches, multiplied by the binary number representing '8' shown next to the woman gives her height, 64 inches. The figures represent the type of creature that created Pioneer. The man's hand is raised in a gesture of good will. Across the bottom are the planets, ranging outward from the Sun, with the spacecraft trajectory arching away from Earth, passing Mars, and swinging by Jupiter.

  18. Modern supragingival plaque control.

    TOXLINE Toxicology Bibliographic Information

    Iacono VJ; Aldredge WA; Lucks H; Schwartzstein S

    1998-06-01

    Supragingival plaque control is essential for the maintenance of oral health. Despite the many chemotherapeutic agents available as mouthrinses and toothpastes, mechanical plaque removal is still the best method to achieve effective plaque control. This is due, in part, to the lack of development of oral antimicrobials with the effectiveness and substantivity of chlorhexidine gluconate but without its adverse effects of dental staining and calculus formation. The use of the numerous mechanical (manual and electric) oral hygiene devices extant and their effectiveness, however, are dependent upon patient dexterity and compliance and concomitant active professional treatment for the monitoring of home care, oral hygiene instruction and patient motivation. This paper evaluates the current methods available to reduce plaque and gingivitis with emphasis on their effectiveness at both supragingival plaque control and disease prevention. In addition, recent studies on the newer oscillating/rotating electric plaque removers and interdental cleaning devices will be discussed as related to their efficacy and compliance.

  19. First Reported Case of Postirradiation Pseudosclerodermatous Panniculitis After Stereotactic Body Radiation Therapy for the Treatment of Non-Small Cell Lung Cancer.

    PubMed

    Sachsman, Suzanne Michelle; Haydel, Dana Montrell; Kim, Christina Nam-Soo

    2016-02-01

    Postirradiation pseudosclerodermatous panniculitis is a rare complication of radiation therapy that presents as an indurated plaque and/or subcutaneous nodule in an area of previously irradiated tissue. The histopathologic pattern is of mixed lobular and septal panniculitis with necrotic adipocytes and thickened sclerotic septa as well as dense inflammatory infiltrates consisting mainly of histiocytes. The typical time interval is 1 month to several years after treatment with radiation therapy. This is a case of an 86-year-old man with a medical history significant for diffuse large B-cell lymphoma who was given 3 fractions of stereotactic body radiation therapy for treatment of stage IA non-small cell lung adenocarcinoma of the right upper lobe. Two years later, he presented with several small palpable subcutaneous right axillary nodules, which coalesced into a 6-cm firm multilobulated right axillary mass over several weeks. Histopathology showed sclerosing panniculitis with lipomembranous changes and septal fibrosis. This is the first reported case describing postirradiation pseudosclerodermatous panniculitis in a patient with lung cancer treated with stereotactic body radiation therapy. This diagnosis must be differentiated from other subtypes of panniculitis and complications of radiation therapy. PMID:26825159

  20. Enhanced radiation therapy with internalized polyelectrolyte modified nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhang, Peipei; Qiao, Yong; Wang, Chaoming; Ma, Liyuan; Su, Ming

    2014-08-01

    A challenge of X-ray radiation therapy is that high dose X-ray under therapeutic conditions damages normal cells. This paper describes a nanoparticle-based method to enhance X-ray radiation therapy by delivering radio-sensitizing gold nanoparticles into cancer cells. The nanoparticles have been modified with cationic polyelectrolytes to allow internalization. Upon X-ray irradiation of nanoparticles, more photoelectrons and Auger electrons are generated to cause water ionization, leading to formation of free radicals that damage DNA of cancer cells. The X-ray dose required for DNA damage and cell killing is reduced by delivering gold nanoparticles inside cancer cells.

  1. Complications of head and neck radiation therapy and their management

    SciTech Connect

    Engelmeier, R.L.; King, G.E.

    1983-04-01

    Patients who receive radiation therapy to the head and neck suffer potential complications and undesirable side-effects of this therapy. The extent of undesirable responses is dependent on the source of irradiation, the fields of irradiation, and the dose. The radiotherapist determines these factors by the extent, location, and radiosensitivity of the tumor. The potential undesirable side-effects are xerostomia, mucositis, fibrosis, trismus, dermatitis, photosensitivity, radiation caries, soft tissue necrosis, and osteoradionecrosis. Each of these clinical entities and their proposed management have been discussed.

  2. Phenytoin Induced Erythema Multiforme after Cranial Radiation Therapy.

    PubMed

    Kazanci, Atilla; Tekkök, İsmail Hakkı

    2015-08-01

    The prophylactic use of phenytoin during and after brain surgery and cranial irradiation is a common measure in brain tumor therapy. Phenytoin has been associated with variety of adverse skin reactions including urticaria, erythroderma, erythema multiforme (EM), Stevens-Johnson syndrome, and toxic epidermal necrolysis. EM associated with phenytoin and cranial radiation therapy (EMPACT) is a rare specific entity among patients with brain tumors receiving radiation therapy while on prophylactic anti-convulsive therapy. Herein we report a 41-year-old female patient with left temporal glial tumor who underwent surgery and then received whole brain radiation therapy and chemotherapy. After 24 days of continous prophylactic phenytoin therapy the patient developed minor skin reactions and 2 days later the patient returned with generalized erythamatous and itchy maculopapuler rash involving neck, chest, face, trunk, extremities. There was significant periorbital and perioral edema. Painful mucosal lesions consisting of oral and platal erosions also occurred and prevented oral intake significantly. Phenytoin was discontinued gradually. Systemic admistration of corticosteroids combined with topical usage of steroids for oral lesions resulted in complete resolution of eruptions in 3 weeks. All cutaneous lesions in patients with phenytoin usage with the radiotherapy must be evoluated with suspicion for EM. PMID:26361537

  3. Phenytoin Induced Erythema Multiforme after Cranial Radiation Therapy

    PubMed Central

    Tekkök, İsmail Hakkı

    2015-01-01

    The prophylactic use of phenytoin during and after brain surgery and cranial irradiation is a common measure in brain tumor therapy. Phenytoin has been associated with variety of adverse skin reactions including urticaria, erythroderma, erythema multiforme (EM), Stevens-Johnson syndrome, and toxic epidermal necrolysis. EM associated with phenytoin and cranial radiation therapy (EMPACT) is a rare specific entity among patients with brain tumors receiving radiation therapy while on prophylactic anti-convulsive therapy. Herein we report a 41-year-old female patient with left temporal glial tumor who underwent surgery and then received whole brain radiation therapy and chemotherapy. After 24 days of continous prophylactic phenytoin therapy the patient developed minor skin reactions and 2 days later the patient returned with generalized erythamatous and itchy maculopapuler rash involving neck, chest, face, trunk, extremities. There was significant periorbital and perioral edema. Painful mucosal lesions consisting of oral and platal erosions also occurred and prevented oral intake significantly. Phenytoin was discontinued gradually. Systemic admistration of corticosteroids combined with topical usage of steroids for oral lesions resulted in complete resolution of eruptions in 3 weeks. All cutaneous lesions in patients with phenytoin usage with the radiotherapy must be evoluated with suspicion for EM. PMID:26361537

  4. Synchrotron Radiation Therapy from a Medical Physics point of view

    NASA Astrophysics Data System (ADS)

    Prezado, Y.; Adam, J. F.; Berkvens, P.; Martinez-Rovira, I.; Fois, G.; Thengumpallil, S.; Edouard, M.; Vautrin, M.; Deman, P.; Bräuer-Krisch, E.; Renier, M.; Elleaume, H.; Estève, F.; Bravin, A.

    2010-07-01

    Synchrotron radiation (SR) therapy is a promising alternative to treat brain tumors, whose management is limited due to the high morbidity of the surrounding healthy tissues. Several approaches are being explored by using SR at the European Synchrotron Radiation Facility (ESRF), where three techniques are under development Synchrotron Stereotactic Radiation Therapy (SSRT), Microbeam Radiation Therapy (MRT) and Minibeam Radiation Therapy (MBRT). The sucess of the preclinical studies on SSRT and MRT has paved the way to clinical trials currently in preparation at the ESRF. With this aim, different dosimetric aspects from both theoretical and experimental points of view have been assessed. In particular, the definition of safe irradiation protocols, the beam energy providing the best balance between tumor treatment and healthy tissue sparing in MRT and MBRT, the special dosimetric considerations for small field dosimetry, etc will be described. In addition, for the clinical trials, the definition of appropiate dosimetry protocols for patients according to the well established European Medical Physics recommendations will be discussed. Finally, the state of the art of the MBRT technical developments at the ESRF will be presented. In 2006 A. Dilmanian and collaborators proposed the use of thicker microbeams (0.36-0.68 mm). This new type of radiotherapy is the most recently implemented technique at the ESRF and it has been called MBRT. The main advantage of MBRT with respect to MRT is that it does not require high dose rates. Therefore it can be more easily applied and extended outside synchrotron sources in the future.

  5. Synchrotron Radiation Therapy from a Medical Physics point of view

    SciTech Connect

    Prezado, Y.; Berkvens, P.; Braeuer-Krisch, E.; Renier, M.; Bravin, A.; Adam, J. F.; Martinez-Rovira, I.; Fois, G.; Thengumpallil, S.; Edouard, M.; Deman, P.; Vautrin, M.

    2010-07-23

    Synchrotron radiation (SR) therapy is a promising alternative to treat brain tumors, whose management is limited due to the high morbidity of the surrounding healthy tissues. Several approaches are being explored by using SR at the European Synchrotron Radiation Facility (ESRF), where three techniques are under development Synchrotron Stereotactic Radiation Therapy (SSRT), Microbeam Radiation Therapy (MRT) and Minibeam Radiation Therapy (MBRT).The sucess of the preclinical studies on SSRT and MRT has paved the way to clinical trials currently in preparation at the ESRF. With this aim, different dosimetric aspects from both theoretical and experimental points of view have been assessed. In particular, the definition of safe irradiation protocols, the beam energy providing the best balance between tumor treatment and healthy tissue sparing in MRT and MBRT, the special dosimetric considerations for small field dosimetry, etc will be described. In addition, for the clinical trials, the definition of appropiate dosimetry protocols for patients according to the well established European Medical Physics recommendations will be discussed. Finally, the state of the art of the MBRT technical developments at the ESRF will be presented. In 2006 A. Dilmanian and collaborators proposed the use of thicker microbeams (0.36-0.68 mm). This new type of radiotherapy is the most recently implemented technique at the ESRF and it has been called MBRT. The main advantage of MBRT with respect to MRT is that it does not require high dose rates. Therefore it can be more easily applied and extended outside synchrotron sources in the future.

  6. Radiation Therapy for Primary Central Nervous System Lymphoma

    PubMed Central

    Shibamoto, Yuta

    2013-01-01

    Up until the late 1970s, radiation therapy played an important role in the treatment of primary central nervous system lymphoma (PCNSL) but more recently its role has changed due to the increased use of systemic chemotherapy. In this article, the current status of radiotherapy for PCNSL and optimal forms of radiotherapy, including the treatment volume and radiation dose, are discussed. Data from nationwide Japanese surveys of PCNSL patients treated with radiation therapy suggest that the prognosis of PCNSL patients improved during the 1990s, in part due to the use of high-dose methotrexate-containing chemotherapy. The prognosis of patients treated with radiation alone also improved. Radiotherapy still seems to play an important role in the attempt to cure this disease. PMID:25992225

  7. Maxillary sinus carcinoma: result of radiation therapy

    SciTech Connect

    Shibuya, H.; Horiuchi, J.; Suzuki, S.; Shioda, S.; Enomoto, S.

    1984-07-01

    This hundred and sixteen patients with carcinoma of the maxillary sinus received primary therapy consisting of external beam irradiation alone or in combination with surgery and/or chemotherapy at the Department of Radiology, Tokyo Medical and Dental University Hospital, between 1953 and 1982. In our institution, methods of treating cancer of the maxillary sinus have been changed from time to time and showed different control rates and clinical courses. An actuarial 10-year survival rate of 21% has been obtained by the megavoltage irradiation alone as well as 34% actuarial 10-year survival rate by megavoltage irradiation with surgery. After the introduction of conservative surgery followed by conventional trimodal combination therapy, the local control rate has been improved. The amount of functional, cosmetic, and brain damages have been remarkably decreased by this mode of therapy. The actuarial five year survival rate was 67%. In addition, along with the improvement of the local control rate, the control of nodal and distant organ metastases have been emerging as one of the important contributions to the prognosis of this disease.

  8. [Cisplatin and derivatives with radiation therapy: for what clinical use?].

    PubMed

    Durdux, C

    2004-11-01

    Since its discovery by Rosenberg in 1965, cisplatin and its derivatives have appeared as the most important chemotherapeutic agents, particularly for their radiosensitizing properties and their clinical use with radiation. In spite of numerous preclinical and clinical studies, optimal schedules of platin and radiotherapy combination have to be defined. The first part of this overview will describe biological mechanisms of interaction between radiation therapy and platinum derivatives. The second part will report the major clinical impact of their association. PMID:15679253

  9. Hypofractionated radiation therapy for prostate cancer: biologic and technical considerations

    PubMed Central

    Sanfilippo, Nicholas J; Cooper, Benjamin T

    2014-01-01

    The optimal radiation schedule for the curative treatment of prostate cancer is not known. The dose-response of tumors and normal tissues to fractionated irradiation can be described according to a parameter called the alpha-beta ratio (?/?). In the past several years numerous reports have been published that suggest that the alpha-beta ratio for prostate cancer may be quite low; between 1 and 3. If this hypothesis is true, then a radiation therapy schedule that employs less frequent and larger fractions, termed hypofractionation, may be more efficacious. Multiple randomized trials have been conducted comparing moderate (less than 5 Gy/day) hypofractionated radiation therapy and standard radiation therapy in men with prostate cancer. In the majority of these studies the moderate hypofractionated arm had equivalent efficacy with a similar or improved side effect profile. One area to use caution may be in patients with compromised (IPSS > 12) urinary function at baseline due to an increase in urinary toxicity observed in patients treated with hypofractionated radiation in one study. Extreme hypofractionation (greater than or equal to 5 Gy/day), is currently being compared in a randomized trial. Early prospectively collected data from multiple institutions demonstrates efficacy and toxicity that compares favorably with historical controls. The cost savings from hypofractionation could be profound on a national level and only increases the necessity of testing hypofractionated treatment schedules. Long term data and future trials will help radiation oncologists determine the ideal fractionation scheme based on cost, efficacy, and toxicity. PMID:25606574

  10. Symptomatic and asymptomatic carotid artery plaque

    PubMed Central

    Mughal, Majid M; Khan, Mohsin K; DeMarco, J Kevin; Majid, Arshad; Shamoun, Fadi; Abela, George S

    2011-01-01

    Carotid atherosclerotic plaques represent both stable and unstable atheromatous lesions. Atherosclerotic plaques that are prone to rupture owing to their intrinsic composition such as a large lipid core, thin fibrous cap and intraplaque hemorrhage are associated with subsequent thromboembolic ischemic events. At least 15–20% of all ischemic strokes are attributable to carotid artery atherosclerosis. Characterization of plaques may enhance the understanding of natural history and ultimately the treatment of atherosclerotic disease. MRI of carotid plaque and embolic signals during transcranial Doppler have identified features beyond luminal stenosis that are predictive of future transient ischemic attacks and stroke. The value of specific therapies to prevent stroke in symptomatic and asymptomatic patients with severe carotid artery stenosis are the subject of current research and analysis of recently published clinical trials that are discussed in this article. PMID:21985544

  11. Comparison of three dimensional conformal radiation therapy, intensity modulated radiation therapy and volumetric modulated arc therapy for low radiation exposure of normal tissue in patients with prostate cancer.

    PubMed

    Cakir, Aydin; Akgun, Zuleyha; Fayda, Merdan; Agaoglu, Fulya

    2015-01-01

    Radiotherapy has an important role in the treatment of prostate cancer. Three-dimensional conformal radiation therapy (3D-CRT), intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) techniques are all applied for this purpose. However, the risk of secondary radiation-induced bladder cancer is significantly elevated in irradiated patients compared surgery-only or watchful waiting groups. There are also reports of risk of secondary cancer with low doses to normal tissues. This study was designed to compare received volumes of low doses among 3D-CRT, IMRT and VMAT techniques for prostate patients. Ten prostate cancer patients were selected retrospectively for this planning study. Treatment plans were generated using 3D-CRT, IMRT and VMAT techniques. Conformity index (CI), homogenity index (HI), receiving 5 Gy of the volume (V5%), receiving 2 Gy of the volume (V2%), receiving 1 Gy of the volume (V1%) and monitor units (MUs) were compared. This study confirms that VMAT has slightly better CI while thev olume of low doses was higher. VMAT had lower MUs than IMRT. 3D-CRT had the lowest MU, CI and HI. If target coverage and normal tissue sparing are comparable between different treatment techniques, the risk of second malignancy should be a important factor in the selection of treatment. PMID:25921146

  12. Pelvic radiation therapy: Between delight and disaster

    PubMed Central

    Morris, Kirsten AL; Haboubi, Najib Y

    2015-01-01

    In the last few decades radiotherapy was established as one of the best and most widely used treatment modalities for certain tumours. Unfortunately that came with a price. As more people with cancer survive longer an ever increasing number of patients are living with the complications of radiotherapy and have become, in certain cases, difficult to manage. Pelvic radiation disease (PRD) can result from ionising radiation-induced damage to surrounding non-cancerous tissues resulting in disruption of normal physiological functions and symptoms such as diarrhoea, tenesmus, incontinence and rectal bleeding. The burden of PRD-related symptoms, which impact on a patient’s quality of life, has been under appreciated and sub-optimally managed. This article serves to promote awareness of PRD and the vast potential there is to improve current service provision and research activities. PMID:26649150

  13. Phototherapy cabinet for ultraviolet radiation therapy

    SciTech Connect

    Horwitz, S.N.; Frost, P.

    1981-08-01

    A newly designed cabinet can be used for the treatment of psoriasis with fluorescent ultraviolet (UV) lamps. the new design provides more uniform distribution of UV radiation in both the horizontal and vertical axes, and several safety features have been added. The distribution and uniformity of UV output in this and in a previously described cabinet are compared. The UV output at the vertical center of the older UV light cabinet was six times greater than that at either the top or bottom, while the design of the present cabinet provides uniform UV radiation except for a slight increase at head height and at the level of the lower legs compared with the middle third of the cabinet. The variation in output of the older cabinet may, in part, explain the commonly encountered difficulty in the phototherapy of psoriasis of the scalp and lower extremities.

  14. Radiation therapy for primary optic nerve meningiomas

    SciTech Connect

    Smith, J.L.; Vuksanovic, M.M.; Yates, B.M.; Bienfang, D.C.

    1981-06-01

    Optic nerve sheath meningiomas, formerly thought to be rare, have been encountered with surprising frequency since the widespread use of computed tomography. Early diagnosis led to an enthusiastic surgical approach to these lesions, but this has been tempered by the realization that even in the best of hands, blindness followed such surgery with distressing frequency. Optic nerve sheath meningiomas may be divided into primary, secondary, and multiple meningioma groups. Five patients with primary optic nerve sheath meningiomas treated with irradiation therapy are presented in this report. Improvement in visual acuity, stabilization to increase in the visual field, and decrease in size to total regression of optociliary veins, have been documented following irradiation therapy of the posterior orbital and intracanalicular portions of the optic nerve in some of these cases. Although each patient must be carefully individualized, there is no question that visual palliation can be achieved in some cases of optic nerve sheath meningioma. Further investigation of this therapeutic modality in selected cases in advised.

  15. Acute parotitis and hyperamylasemia following whole-brain radiation therapy

    SciTech Connect

    Cairncross, J.G.; Salmon, J.; Kim, J.H.; Posner, J.B.

    1980-04-01

    Parotitis, an infrequent, previously unreported complication of whole-brain radiation therapy, was observed in 4 patients. The acute symptoms, which include fever, dry mouth, pain, swelling, and tenderness, are accompanied by hyperamylasemia. Among 10 patients receiving whole-brain irradiation, 8 had serum amylase elevations without symptoms. Both acute parotitis and asymptomatic hyperamylasemia result from irradiation of the parotid glands.

  16. Factors influencing radiation therapy student clinical placement satisfaction

    PubMed Central

    Bridge, Pete; Carmichael, Mary-Ann

    2014-01-01

    Introduction: Radiation therapy students at Queensland University of Technology (QUT) attend clinical placements at five different clinical departments with varying resources and support strategies. This study aimed to determine the relative availability and perceived importance of different factors affecting student support while on clinical placement. The purpose of the research was to inform development of future support mechanisms to enhance radiation therapy students’ experience on clinical placement. Methods: This study used anonymous Likert-style surveys to gather data from years 1 and 2 radiation therapy students from QUT and clinical educators from Queensland relating to availability and importance of support mechanisms during clinical placements in a semester. Results: The study findings demonstrated student satisfaction with clinical support and suggested that level of support on placement influenced student employment choices. Staff support was perceived as more important than physical resources; particularly access to a named mentor, a clinical educator and weekly formative feedback. Both students and educators highlighted the impact of time pressures. Conclusions: The support offered to radiation therapy students by clinical staff is more highly valued than physical resources or models of placement support. Protected time and acknowledgement of the importance of clinical education roles are both invaluable. Joint investment in mentor support by both universities and clinical departments is crucial for facilitation of effective clinical learning. PMID:26229635

  17. 21 CFR 892.5750 - Radionuclide radiation therapy system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radionuclide radiation therapy system. 892.5750 Section 892.5750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... patient's body. This generic type of device may include signal analysis and display equipment, patient...

  18. 21 CFR 892.5750 - Radionuclide radiation therapy system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radionuclide radiation therapy system. 892.5750 Section 892.5750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... patient's body. This generic type of device may include signal analysis and display equipment, patient...

  19. 21 CFR 892.5750 - Radionuclide radiation therapy system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radionuclide radiation therapy system. 892.5750 Section 892.5750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... patient's body. This generic type of device may include signal analysis and display equipment, patient...

  20. 21 CFR 892.5750 - Radionuclide radiation therapy system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radionuclide radiation therapy system. 892.5750 Section 892.5750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... patient's body. This generic type of device may include signal analysis and display equipment, patient...

  1. Radiation therapy in the management of patients with mesothelioma

    SciTech Connect

    Gordon, W. Jr.; Antman, K.H.; Greenberger, J.S.; Weichselbaum, R.R.; Chaffey, J.T.

    1982-01-01

    The results of radiation therapy in the management of 27 patients with malignant mesothelioma were reviewed. Eight patients were treated with a curative intent combining attempted surgical excision of tumor (thoracic in 6 and peritoneal in 2), aggressive radiation therapy, and combination chemotherapy using an adriamycin-containing regimen. One patient achieved a 2-year disease-free inteval followed by recurrence of tumor above the thoracic irradiation field. This patient was retreated with localized irradiation and is disease-free after 5 years of initial diagnosis. One patient has persistent abdominal disease at 18 months; the other 6 patients suffered local recurrence within 8-13 months of initiation of treatment. Radiation therapy was used in 19 other patients who received 29 courses for palliation of dyspnea, superior vena cava syndrome, dysphagia, or neurological symptoms of brain metastasis. A palliation index was used to determine the effectiveness of irradiation and revealed that relief of symptoms was complete or substantial in 5 treatment courses, moderately effective in 6 courses and inadequate in 18 treatment courses. Adequate palliation strongly correlated with a dose at or above 4,000 rad in 4 weeks. The management of patients with mesothelioma requires new and innovative approaches to increase the effectiveness of radiation therapy and minimize the significant potential combined toxicity of pulmonary irradiation and adriamycin.

  2. Factors influencing radiation therapy student clinical placement satisfaction

    SciTech Connect

    Bridge, Pete; Carmichael, Mary-Ann

    2014-02-15

    Introduction: Radiation therapy students at Queensland University of Technology (QUT) attend clinical placements at five different clinical departments with varying resources and support strategies. This study aimed to determine the relative availability and perceived importance of different factors affecting student support while on clinical placement. The purpose of the research was to inform development of future support mechanisms to enhance radiation therapy students’ experience on clinical placement. Methods: This study used anonymous Likert-style surveys to gather data from years 1 and 2 radiation therapy students from QUT and clinical educators from Queensland relating to availability and importance of support mechanisms during clinical placements in a semester. Results: The study findings demonstrated student satisfaction with clinical support and suggested that level of support on placement influenced student employment choices. Staff support was perceived as more important than physical resources; particularly access to a named mentor, a clinical educator and weekly formative feedback. Both students and educators highlighted the impact of time pressures. Conclusions: The support offered to radiation therapy students by clinical staff is more highly valued than physical resources or models of placement support. Protected time and acknowledgement of the importance of clinical education roles are both invaluable. Joint investment in mentor support by both universities and clinical departments is crucial for facilitation of effective clinical learning.

  3. Orbital leiomyosarcoma after radiation therapy for bilateral retinoblastoma

    SciTech Connect

    Folberg, R.; Cleasby, G.; Flanagan, J.A.; Spencer, W.H.; Zimmerman, L.E.

    1983-10-01

    Leiomyosarcoma rarely occurs in the orbit and is seldom encountered as a postirradiation sarcoma in any anatomic location. Three patients with bilateral retinoblastoma who had received radiation therapy are known to have orbital leiomyosarcoma develop in their third decade of life. The clinical and pathological data pertaining to two of these patients are given and discussed herein.

  4. Optimization of sup 125 I ophthalmic plaque brachytherapy

    SciTech Connect

    Astrahan, M.A.; Luxton, G.; Jozsef, G.; Liggett, P.E.; Petrovich, Z. )

    1990-11-01

    Episcleral plaques containing {sup 125}I sources are often used in the treatment of ocular melanoma. Within four years post-treatment, however, the majority of patients experience some visual loss due to radiation retinopathy. The high incidence of late complications suggests that careful treatment optimization may lead to improved outcome. The goal of optimization would be to reduce the magnitude of vision-limiting complications without compromising tumor control. We have developed a three-dimensional computer model for ophthalmic plaque therapy which permits us to explore the potential of various optimization strategies. One simple strategy which shows promise is to maximize the ratio of dose to the tumor apex (T) compared to dose to the macula (M). By modifying the parameters of source location, activity distribution, source orientation, and shielding we find that the calculated T:M ratio can be varied by a factor of 2 for a common plaque design and posterior tumor location. Margins and dose to the tumor volume remain essentially unchanged.

  5. The Application of FLUKA to Dosimetry and Radiation Therapy

    NASA Technical Reports Server (NTRS)

    Wilson, Thomas L.; Andersen, Victor; Pinsky, Lawrence; Ferrari, Alfredo; Battistoni, Giusenni

    2005-01-01

    Monte Carlo transport codes like FLUKA are useful for many purposes, and one of those is the simulation of the effects of radiation traversing the human body. In particular, radiation has been used in cancer therapy for a long time, and recently this has been extended to include heavy ion particle beams. The advent of this particular type of therapy has led to the need for increased capabilities in the transport codes used to simulate the detailed nature of the treatment doses to the Y O U S tissues that are encountered. This capability is also of interest to NASA because of the nature of the radiation environment in space.[l] While in space, the crew members bodies are continually being traversed by virtually all forms of radiation. In assessing the risk that this exposure causes, heavy ions are of primary importance. These arise both from the primary external space radiation itself, as well as fragments that result from interactions during the traversal of that radiation through any intervening material including intervening body tissue itself. Thus the capability to characterize the details of the radiation field accurately within a human body subjected to such external 'beams" is of critical importance.

  6. Evaluation of neutron radiation field in carbon ion therapy

    NASA Astrophysics Data System (ADS)

    Jun-Kui, Xu; You-Wu, Su; Wu-Yuan, Li; Wei-Wei, Yan; Xi-Meng, Chen; Wang, Mao; Cheng-Guo, Pang

    2016-01-01

    Carbon ions have significant advantages in tumor therapy because of their physical and biological properties. In view of the radiation protection, the safety of patients is the most important issue in therapy processes. Therefore, the effects of the secondary particles produced by the carbon ions in the tumor therapy should be carefully considered, especially for the neutrons. In the present work, the neutron radiation field induced by carbon ions was evaluated by using the FLUKA code. The simulated results of neutron energy spectra and neutron dose was found to be in good agreement with the experiment data. In addition, energy deposition of carbon ions and neutrons in tissue-like media was studied, it is found that the secondary neutron energy deposition is not expected to exceed 1% of the carbon ion energy deposition in a typical treatment.

  7. Thyroid cancer radioiodine therapy: health service performance and radiation safety.

    PubMed

    Vogiatzi, S; Liossis, A; Lamprinakou, M

    2015-07-01

    Greek Atomic Energy Commission collected data related to radioiodine I-131 therapy (RAIT) delivery to differentiated thyroid carcinoma patients, for the period 2003-13, corresponding to 100 % of hospitals at national level. Radiation safety and health service performance outcome indicators were assessed. The numbers of hospitals and nuclear medicine (NM) therapy wards, as well as RAIT annual frequencies, have increased. Geographical inhomogeneous distribution of existing infrastructure is recorded. In some cases, the observed inefficient use of NM therapy wards seems to be due to lack of human resources (e.g. nurses). Regular assessment of appropriate key indicators could serve as a useful tool for radiation safety monitoring and health service performance improvement. PMID:25809109

  8. Radiation Therapy for Liver Tumors: Ready for Inclusion in Guidelines?

    PubMed Central

    Tanguturi, Shyam K.; Wo, Jennifer Y.; Zhu, Andrew X.; Dawson, Laura A.

    2014-01-01

    Despite the historically limited role of radiotherapy in the management of primary hepatic malignancies, modern advances in treatment design and delivery have renewed enthusiasm for radiation as a potentially curative treatment modality. Surgical resection and/or liver transplantation are traditionally regarded as the most effective forms of therapy, although the majority of patients with hepatocellular carcinoma and intrahepatic cholangiocarcinoma present with locally advanced or unresectable disease on the basis of local vascular invasion or inadequate baseline hepatobiliary function. In this context, many efforts have focused on nonoperative treatment approaches including novel systemic therapies, transarterial chemoembolization, ethanol ablation, radiofrequency ablation, and stereotactic body radiation therapy (SBRT). This review aims to summarize modern advances in radiotherapy, particularly SBRT, in the treatment of primary hepatic malignancies. PMID:25001265

  9. QA in Radiation Therapy: The RPC Perspective

    NASA Astrophysics Data System (ADS)

    Ibbott, G. S.

    2010-11-01

    The Radiological Physics Center (RPC) is charged with assuring the consistent delivery of radiation doses to patients on NCI-sponsored clinical trials. To accomplish this, the RPC conducts annual mailed audits of machine calibration, dosimetry audit visits to institutions, reviews of treatment records, and credentialing procedures requiring the irradiation of anthropomorphic phantoms. Through these measurements, the RPC has gained an understanding of the level of quality assurance practiced in this cohort of institutions, and a database of measurements of beam characteristics of a large number of treatment machines. The results of irradiations of phantoms have yielded insight into the delivery of advanced technology treatment procedures.

  10. Complementary strategies for the management of radiation therapy side effects.

    PubMed

    Stubbe, Christine E; Valero, Meighan

    2013-07-01

    Patients with cancer utilize complementary and alternative medicine (CAM) for a variety of purposes, one of which is the reduction of side effects of conventional treatment. With a large number of their patients using CAM, it is important for advanced practitioners in oncology to have an understanding of these therapies to better guide their patients. Side effects of radiation therapy that may have dose-limiting poten-tial include diarrhea, mucositis, skin toxicity, and xerostomia. A com-mon side effect that is not necessarily dose-limiting but considerably troublesome to patients is cancer- and treatment-related fatigue. The CAM therapies that may alleviate some of the side effects of radiation therapy include probiotics, psyllium, exercise, melatonin, honey, acu-puncture, and calendula. Therapies that require more research or have been shown to be ineffective include aloe vera, glutamine, and deglyc-yrrhizinated licorice. This article provides an overview of these thera-pies as well as related research and analysis. PMID:25032003

  11. BRCA1 Mutation: A Predictive Marker for Radiation Therapy?

    SciTech Connect

    Kan, Charlene; Zhang, Junran

    2015-10-01

    DNA repair, in particular, DNA double-strand break (DSB) repair, is essential for the survival of both normal and cancer cells. An elaborate repair mechanism has been developed in cells to efficiently repair the damaged DNA. The pathways predominately involved in DSB repair are homologous recombination and classic nonhomologous end-joining, although the alternative NHEJ pathway, a third DSB repair pathway, could also be important in certain contexts. The protein of BRCA1 encoded by the tumor suppressor gene BRCA1 regulates all DSB repair pathways. Given that DSBs represent the most biologically significant lesions induced by ionizing radiation and that impaired DSB repair leads to radiation sensitivity, it has been expected that cancer patients with BRCA1 mutations should benefit from radiation therapy. However, the clinical data have been conflicting and inconclusive. We provide an overview about the current status of the data regarding BRCA1 deficiency and radiation therapy sensitivity in both experimental models and clinical investigations. In addition, we discuss a strategy to potentiate the effects of radiation therapy by poly(ADP-ribose) polymerase inhibitors, the pharmacologic drugs being investigated as monotherapy for the treatment of patients with BRCA1/2 mutations.

  12. BRCA1 Mutation: A Predictive Marker for Radiation Therapy?

    PubMed

    Kan, Charlene; Zhang, Junran

    2015-10-01

    DNA repair, in particular, DNA double-strand break (DSB) repair, is essential for the survival of both normal and cancer cells. An elaborate repair mechanism has been developed in cells to efficiently repair the damaged DNA. The pathways predominately involved in DSB repair are homologous recombination and classic nonhomologous end-joining, although the alternative NHEJ pathway, a third DSB repair pathway, could also be important in certain contexts. The protein of BRCA1 encoded by the tumor suppressor gene BRCA1 regulates all DSB repair pathways. Given that DSBs represent the most biologically significant lesions induced by ionizing radiation and that impaired DSB repair leads to radiation sensitivity, it has been expected that cancer patients with BRCA1 mutations should benefit from radiation therapy. However, the clinical data have been conflicting and inconclusive. We provide an overview about the current status of the data regarding BRCA1 deficiency and radiation therapy sensitivity in both experimental models and clinical investigations. In addition, we discuss a strategy to potentiate the effects of radiation therapy by poly(ADP-ribose) polymerase inhibitors, the pharmacologic drugs being investigated as monotherapy for the treatment of patients with BRCA1/2 mutations. PMID:26383678

  13. Immunomodulatory effects of radiation: what is next for cancer therapy?

    PubMed

    Kumari, Anita; Simon, Samantha S; Moody, Tomika D; Garnett-Benson, Charlie

    2016-01-01

    Despite its former reputation as being immunosuppressive, it has become evident that radiation therapy can enhance antitumor immune responses. This quality can be harnessed by utilizing radiation as an adjuvant to cancer immunotherapies. Most studies combine the standard radiation dose and regimens indicated for the given disease state, with novel cancer immunotherapies. It has become apparent that low-dose radiation, as well as doses within the hypofractionated range, can modulate tumor cells making them better targets for immune cell reactivity. Herein, we describe the range of phenotypic changes induced in tumor cells by radiation, and explore the diverse mechanisms of immunogenic modulation reported at these doses. We also review the impact of these doses on the immune cell function of cytotoxic cells in vivo and in vitro. PMID:26621553

  14. Gastrointestinal Toxicities With Combined Antiangiogenic and Stereotactic Body Radiation Therapy

    PubMed Central

    Pollom, Erqi L.; Deng, Lei; Pai, Reetesh K.; Brown, J. Martin; Giaccia, Amato; Loo, Billy W.; Shultz, David B.; Le, Quynh Thu; Koong, Albert C.; Chang, Daniel T.

    2016-01-01

    Combining the latest targeted biologic agents with the most advanced radiation technologies has been an exciting development in the treatment of cancer patients. Stereotactic body radiation therapy (SBRT) is an ablative radiation approach that has become established for the treatment of a variety of malignancies, and it has been increasingly used in combination with biologic agents, including those targeting angiogenesis-specific pathways. Multiple reports have emerged describing unanticipated toxicities arising from the combination of SBRT and angiogenesis-targeting agents, particularly of late luminal gastrointestinal toxicities. In this review, we summarize the literature describing these toxicities, explore the biological mechanism of action of toxicity with the combined use of antiangiogenic therapies, and discuss areas of future research, so that this combination of treatment modalities can continue to be used in broader clinical contexts. PMID:26068491

  15. Research Findings on Radiation Hormesis and Radon Therapy

    SciTech Connect

    Hattori, Sadao

    1999-06-06

    Radiation hormesis research in Japan to determine the validity of Luckey's claims has revealed information on the health effects of low-level radiation. The scientific data of animal tests we obtained and successful results actually brought by radon therapy on human patients show us a clearer understanding of the health effects of low-level radiation. We obtained many animal test results and epidemiological survey data through our research activities cooperating with more than ten universities in Japan, categorized as follows: 1. suppression of cancer by enhancement of the immune system based on gene activation; 2. rejuvenation and suppression of aging by increasing cell membrane permeability and enzyme syntheses; 3. adaptive response by activation of gene expression on DNA repair and cell apoptosis; 4. pain relief and stress moderation by hormone formation in the brain and central nervous system; 5. avoidance and therapy of obstinate diseases by enhancing damage control systems and form one formation.

  16. Gastrointestinal Toxicities With Combined Antiangiogenic and Stereotactic Body Radiation Therapy

    SciTech Connect

    Pollom, Erqi L.; Deng, Lei; Pai, Reetesh K.; Brown, J. Martin; Giaccia, Amato; Loo, Billy W.; Shultz, David B.; Le, Quynh Thu; Koong, Albert C.; Chang, Daniel T.

    2015-07-01

    Combining the latest targeted biologic agents with the most advanced radiation technologies has been an exciting development in the treatment of cancer patients. Stereotactic body radiation therapy (SBRT) is an ablative radiation approach that has become established for the treatment of a variety of malignancies, and it has been increasingly used in combination with biologic agents, including those targeting angiogenesis-specific pathways. Multiple reports have emerged describing unanticipated toxicities arising from the combination of SBRT and angiogenesis-targeting agents, particularly of late luminal gastrointestinal toxicities. In this review, we summarize the literature describing these toxicities, explore the biological mechanism of action of toxicity with the combined use of antiangiogenic therapies, and discuss areas of future research, so that this combination of treatment modalities can continue to be used in broader clinical contexts.

  17. Review and Uses of Stereotactic Body Radiation Therapy for Oligometastases

    PubMed Central

    Alongi, Filippo; Filippi, Andrea Riccardo; Ricardi, Umberto; Scorsetti, Marta

    2012-01-01

    In patients with proven distant metastases from solid tumors, it has been a notion that the condition is incurable, warranting palliative care only. The term “oligometastases” was coined to refer to isolated sites of metastasis, whereby the entire burden of disease can be recognized as a finite number of discrete lesions that can be potentially cured with local therapies. Stereotactic body radiation therapy (SBRT) is a novel treatment modality in radiation oncology that delivers a very high dose of radiation to the tumor target with high precision using single or a small number of fractions. SBRT is the result of technological advances in patient and tumor immobilization, image guidance, and treatment planning and delivery. A number of studies, both retrospective and prospective, showed promising results in terms of local tumor control and, in a limited subset of patients, of survival. This article reviews the radiobiologic, technical, and clinical aspects of SBRT for various anatomical sites. PMID:22723509

  18. Gastrointestinal Toxicities With Combined Antiangiogenic and Stereotactic Body Radiation Therapy.

    PubMed

    Pollom, Erqi L; Deng, Lei; Pai, Reetesh K; Brown, J Martin; Giaccia, Amato; Loo, Billy W; Shultz, David B; Le, Quynh Thu; Koong, Albert C; Chang, Daniel T

    2015-07-01

    Combining the latest targeted biologic agents with the most advanced radiation technologies has been an exciting development in the treatment of cancer patients. Stereotactic body radiation therapy (SBRT) is an ablative radiation approach that has become established for the treatment of a variety of malignancies, and it has been increasingly used in combination with biologic agents, including those targeting angiogenesis-specific pathways. Multiple reports have emerged describing unanticipated toxicities arising from the combination of SBRT and angiogenesis-targeting agents, particularly of late luminal gastrointestinal toxicities. In this review, we summarize the literature describing these toxicities, explore the biological mechanism of action of toxicity with the combined use of antiangiogenic therapies, and discuss areas of future research, so that this combination of treatment modalities can continue to be used in broader clinical contexts. PMID:26068491

  19. High dose bystander effects in spatially fractionated radiation therapy.

    PubMed

    Asur, Rajalakshmi; Butterworth, Karl T; Penagaricano, Jose A; Prise, Kevin M; Griffin, Robert J

    2015-01-01

    Traditional radiotherapy of bulky tumors has certain limitations. Spatially fractionated radiation therapy (GRID) and intensity modulated radiotherapy (IMRT) are examples of advanced modulated beam therapies that help in significant reductions in normal tissue damage. GRID refers to the delivery of a single high dose of radiation to a large treatment area that is divided into several smaller fields, while IMRT allows improved dose conformity to the tumor target compared to conventional three-dimensional conformal radiotherapy. In this review, we consider spatially fractionated radiotherapy approaches focusing on GRID and IMRT, and present complementary evidence from different studies which support the role of radiation induced signaling effects in the overall radiobiological rationale for these treatments. PMID:24246848

  20. Inflammation and plaque vulnerability.

    PubMed

    Hansson, G K; Libby, P; Tabas, I

    2015-11-01

    Atherosclerosis is a maladaptive, nonresolving chronic inflammatory disease that occurs at sites of blood flow disturbance. The disease usually remains silent until a breakdown of integrity at the arterial surface triggers the formation of a thrombus. By occluding the lumen, the thrombus or emboli detaching from it elicits ischaemic symptoms that may be life-threatening. Two types of surface damage can cause atherothrombosis: plaque rupture and endothelial erosion. Plaque rupture is thought to be caused by loss of mechanical stability, often due to reduced tensile strength of the collagen cap surrounding the plaque. Therefore, plaques with reduced collagen content are thought to be more vulnerable than those with a thick collagen cap. Endothelial erosion, on the other hand, may occur after injurious insults to the endothelium instigated by metabolic disturbance or immune insults. This review discusses the molecular mechanisms involved in plaque vulnerability and the development of atherothrombosis. PMID:26260307

  1. Stem Cell Therapy Remediates Reconstruction of the Craniofacial Skeleton After Radiation Therapy

    PubMed Central

    Deshpande, Sagar S.; Gallagher, Kathleen K.; Donneys, Alexis; Tchanque-Fossuo, Catherine N.; Sarhaddi, Deniz; Sun, Hongli; Krebsbach, Paul H.

    2013-01-01

    This study utilized transplanted bone marrow stromal cells (BMSCs) as a cellular replacement therapy to remedy radiation-induced injury and restore impaired new bone formation during distraction osteogenesis (DO). BMSC therapy brought about the successful generation of new bone and significantly improved both the rate and quality of a bony union of irradiated, distracted [X-ray radiation therapy (XRT)/DO] murine mandibles to the level of nonirradiated DO animals. The bone mineral density and bone volume fraction were also significantly improved by the BMSC replacement therapy showing no difference when compared to nonirradiated animals. Finally, a biomechanical analysis examining the yield, failure load, and ultimate load also demonstrated a significantly improved structural integrity in BMSC-treated XRT/DO mandibles over XRT/DO alone. These results indicate that administration of BMSCs intraoperatively to a radiated distraction gap can function as an adequate stimulant to rescue the ability for irradiated bone to undergo DO and produce a healed regenerate of a vastly superior quality and strength. We believe that the fundamental information on the optimization of bone regeneration in the irradiated mandible provided by this work has immense potential to be translated from the bench to the bedside to lead to improved therapeutic options for patients suffering from the disastrous sequelae of radiation therapy. PMID:23282102

  2. Radiation therapy (RT) after breast-conserving surgery (BCS) in 2015 - The year of radiation therapy advances.

    PubMed

    Kirova, Y M

    2016-04-01

    Surgery associated with radiation therapy is the standard treatment for early breast cancer. This paper reviews the new evidence on local control and survival, the indications of lymph-node irradiation, and the long-term results of large prospective trials. New shorter fractionation schemes allow a reduction in the constraints of daily treatment courses over several weeks, and recent technical improvements in treatment delivery will improve cancer outcomes in terms of local control, decreased toxicity and long-term sequelae. Research should focus on identifying molecular markers for radiation sensitivity while designing specific, targeted modulators of the radiation response in early breast cancer. PMID:26874656

  3. Hepatocellular Carcinoma Radiation Therapy: Review of Evidence and Future Opportunities

    SciTech Connect

    Klein, Jonathan

    2013-09-01

    Hepatocellular carcinoma (HCC) is a leading cause of global cancer death. Curative therapy is not an option for most patients, often because of underlying liver disease. Experience in radiation therapy (RT) for HCC is rapidly increasing. Conformal RT can deliver tumoricidal doses to focal HCC with low rates of toxicity and sustained local control in HCC unsuitable for other locoregional treatments. Stereotactic body RT and particle therapy have been used with long-term control in early HCC or as a bridge to liver transplant. RT has also been effective in treating HCC with portal venous thrombosis. Patients with impaired liver function and extensive disease are at increased risk of toxicity and recurrence. More research on how to combine RT with other standard and novel therapies is warranted. Randomized trials are also needed before RT will be generally accepted as a treatment option for HCC. This review discusses the current state of the literature and opportunities for future research.

  4. Stereotactic Body Radiation Therapy in Spinal Metastases

    SciTech Connect

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

    2012-04-01

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

  5. Some computer graphical user interfaces in radiation therapy

    PubMed Central

    Chow, James C L

    2016-01-01

    In this review, five graphical user interfaces (GUIs) used in radiation therapy practices and researches are introduced. They are: (1) the treatment time calculator, superficial X-ray treatment time calculator (SUPCALC) used in the superficial X-ray radiation therapy; (2) the monitor unit calculator, electron monitor unit calculator (EMUC) used in the electron radiation therapy; (3) the multileaf collimator machine file creator, sliding window intensity modulated radiotherapy (SWIMRT) used in generating fluence map for research and quality assurance in intensity modulated radiation therapy; (4) the treatment planning system, DOSCTP used in the calculation of 3D dose distribution using Monte Carlo simulation; and (5) the monitor unit calculator, photon beam monitor unit calculator (PMUC) used in photon beam radiation therapy. One common issue of these GUIs is that all user-friendly interfaces are linked to complex formulas and algorithms based on various theories, which do not have to be understood and noted by the user. In that case, user only needs to input the required information with help from graphical elements in order to produce desired results. SUPCALC is a superficial radiation treatment time calculator using the GUI technique to provide a convenient way for radiation therapist to calculate the treatment time, and keep a record for the skin cancer patient. EMUC is an electron monitor unit calculator for electron radiation therapy. Instead of doing hand calculation according to pre-determined dosimetric tables, clinical user needs only to input the required drawing of electron field in computer graphical file format, prescription dose, and beam parameters to EMUC to calculate the required monitor unit for the electron beam treatment. EMUC is based on a semi-experimental theory of sector-integration algorithm. SWIMRT is a multileaf collimator machine file creator to generate a fluence map produced by a medical linear accelerator. This machine file controls the multileaf collimator to deliver intensity modulated beams for a specific fluence map used in quality assurance or research. DOSCTP is a treatment planning system using the computed tomography images. Radiation beams (photon or electron) with different energies and field sizes produced by a linear accelerator can be placed in different positions to irradiate the tumour in the patient. DOSCTP is linked to a Monte Carlo simulation engine using the EGSnrc-based code, so that 3D dose distribution can be determined accurately for radiation therapy. Moreover, DOSCTP can be used for treatment planning of patient or small animal. PMUC is a GUI for calculation of the monitor unit based on the prescription dose of patient in photon beam radiation therapy. The calculation is based on dose corrections in changes of photon beam energy, treatment depth, field size, jaw position, beam axis, treatment distance and beam modifiers. All GUIs mentioned in this review were written either by the Microsoft Visual Basic.net or a MATLAB GUI development tool called GUIDE. In addition, all GUIs were verified and tested using measurements to ensure their accuracies were up to clinical acceptable levels for implementations. PMID:27027225

  6. Some computer graphical user interfaces in radiation therapy.

    PubMed

    Chow, James C L

    2016-03-28

    In this review, five graphical user interfaces (GUIs) used in radiation therapy practices and researches are introduced. They are: (1) the treatment time calculator, superficial X-ray treatment time calculator (SUPCALC) used in the superficial X-ray radiation therapy; (2) the monitor unit calculator, electron monitor unit calculator (EMUC) used in the electron radiation therapy; (3) the multileaf collimator machine file creator, sliding window intensity modulated radiotherapy (SWIMRT) used in generating fluence map for research and quality assurance in intensity modulated radiation therapy; (4) the treatment planning system, DOSCTP used in the calculation of 3D dose distribution using Monte Carlo simulation; and (5) the monitor unit calculator, photon beam monitor unit calculator (PMUC) used in photon beam radiation therapy. One common issue of these GUIs is that all user-friendly interfaces are linked to complex formulas and algorithms based on various theories, which do not have to be understood and noted by the user. In that case, user only needs to input the required information with help from graphical elements in order to produce desired results. SUPCALC is a superficial radiation treatment time calculator using the GUI technique to provide a convenient way for radiation therapist to calculate the treatment time, and keep a record for the skin cancer patient. EMUC is an electron monitor unit calculator for electron radiation therapy. Instead of doing hand calculation according to pre-determined dosimetric tables, clinical user needs only to input the required drawing of electron field in computer graphical file format, prescription dose, and beam parameters to EMUC to calculate the required monitor unit for the electron beam treatment. EMUC is based on a semi-experimental theory of sector-integration algorithm. SWIMRT is a multileaf collimator machine file creator to generate a fluence map produced by a medical linear accelerator. This machine file controls the multileaf collimator to deliver intensity modulated beams for a specific fluence map used in quality assurance or research. DOSCTP is a treatment planning system using the computed tomography images. Radiation beams (photon or electron) with different energies and field sizes produced by a linear accelerator can be placed in different positions to irradiate the tumour in the patient. DOSCTP is linked to a Monte Carlo simulation engine using the EGSnrc-based code, so that 3D dose distribution can be determined accurately for radiation therapy. Moreover, DOSCTP can be used for treatment planning of patient or small animal. PMUC is a GUI for calculation of the monitor unit based on the prescription dose of patient in photon beam radiation therapy. The calculation is based on dose corrections in changes of photon beam energy, treatment depth, field size, jaw position, beam axis, treatment distance and beam modifiers. All GUIs mentioned in this review were written either by the Microsoft Visual Basic.net or a MATLAB GUI development tool called GUIDE. In addition, all GUIs were verified and tested using measurements to ensure their accuracies were up to clinical acceptable levels for implementations. PMID:27027225

  7. Managing Radiation Therapy Side Effects: What to Do about Changes When You Urinate

    MedlinePlus

    ... ational C ancer I nstitute Managing Radiation Therapy Side Effects What to do about changes when you urinate “ ... are drinking enough each day. Managing Radiation Therapy Side Effects: Changes when you urinate Ask about drinks or ...

  8. What to Know about Brachytherapy (A Type of Internal Radiation Therapy)

    MedlinePlus

    N ational C ancer I nstitute Understanding Radiation Therapy What To Know About Brachytherapy (A Type of Internal Radiation Therapy) “I asked questions. My doctor took the time to help my family ...

  9. 42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Medicine Technologists, and Radiation Therapy Technologists F Appendix F to Part 75 Public Health PUBLIC..., and Radiation Therapy Technologists The following section describes basic elements to be incorporated... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2....

  10. 42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Medicine Technologists, and Radiation Therapy Technologists F Appendix F to Part 75 Public Health PUBLIC..., and Radiation Therapy Technologists The following section describes basic elements to be incorporated... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2....

  11. 42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Medicine Technologists, and Radiation Therapy Technologists F Appendix F to Part 75 Public Health PUBLIC..., and Radiation Therapy Technologists The following section describes basic elements to be incorporated... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2....

  12. [Evaluation of compensator used in radiation therapy].

    PubMed

    Lin, F J; Cheng, N T; Chen, H H; Chen, C S; Hsien, W L; Leung, W M

    1990-06-20

    A radiation beam incident on an irregular or sloping surface produces skewing of isodose curves and may give rise to unacceptable nonuniformity of the dose distribution within the target volume or cause excessive irradiation of sensitive tissues. The concept of using a compensator, first introduced by Ellis, to circumvent the skewness of isodose curves was elegant. Other workers followed suit elaborating further and extending the procedures. The treatment of chest wall tumors is of special interest and compensators were frequently used in their management. The compensators of aluminum and copper were systematically examined for 6 and 10 MV X-rays. Compensating thickness ratios was determined from equivalent dose measurement at compensating depth by placing compensator at the regular blocking tray for maintaining the skin sparing feature of high energy photon beams. The compensator must compensate not only for the reduction of the primary beam attenuation due to tissue deficit, but also for the loss of scattering by the missing tissues. It was found that the compensating thickness ratios (CTR) was not a constant value and was dependent on the tissue deficit, field size, compensating depth and the material of compensator, but was independent of the energy. As the tissue deficit is increased, the CTR decreases, since the loss of scattering for the deficit volume can be compensated by the lowered attenuation of the compensator. As the field size is increased, the CTR decreases. From the study of central axis depth dose for various deficit thickness, normalized at the median plane of no tissue deficit, it was found that compensator can compensate the dose accurately to one depth only and the compensation to other depth is approximate, and that the compensating error is increased with greater tissue deficit and further depth. The effectiveness of the compensating system with a stair-step polystyrene phantom representative of varying tissue deficits over a small treatment field (20 cm x 20 cm) was also studied with film dosimetry and the error was within 3%. The compensator thickness ratios must be measured in different radiation beams from different treatment machines and in different irradiation conditions because there are major difference between the CTR data obtained directly from experiments and the data besed on calculation from attenuation coefficient mu, physical density rho or electronic density, rho e. The specific CTR reported for aluminum and copper in the literature should only be used as a guideline. PMID:2224603

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

    SciTech Connect

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

    2010-12-01

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

  14. Internal dosimetry for systemic radiation therapy

    SciTech Connect

    Fisher, Darrell R. )

    1999-12-01

    The key to effective use of the medical internal radiation dose (MIRD) schema in radioimmunotherapy (RIT) is to understand how it works and what the essential data input requirements are. The fundamental data are acquired from medical imaging. Image interpretation involves (1) collecting data to determine the source-organ activities, (2) plotting the source-organ time-activity curves, (3) integrating the time-activity curves for an estimate of the residence time, and (4) applying the residence time values (for each important source organ) within the MIRD schema to calculate the tissue absorbed dose to target organs and tumors of interest. This article reviews methods for calculating internal dose. It also describes methods for selecting sampling times, integrating the area under the data curves, and customizing a dose assessment for a patient who does not resemble the MIRD phantom. A sample dose assessment is given, together with common mistakes to avoid. Three approaches to red marrow dosimetry are described. With the increased use of RIT agents for cancer treatment, a solid understanding of internal dose methods is essential for treatment planning and follow-up evaluations.

  15. Complementary Strategies for the Management of Radiation Therapy Side Effects

    PubMed Central

    Stubbe, Christine E.; Valero, Meighan

    2013-01-01

    Patients with cancer utilize complementary and alternative medicine (CAM) for a variety of purposes, one of which is the reduction of side effects of conventional treatment. With a large number of their patients using CAM, it is important for advanced practitioners in oncology to have an understanding of these therapies to better guide their patients. Side effects of radiation therapy that may have dose-limiting poten­tial include diarrhea, mucositis, skin toxicity, and xerostomia. A com­mon side effect that is not necessarily dose-limiting but considerably troublesome to patients is cancer- and treatment-related fatigue. The CAM therapies that may alleviate some of the side effects of radiation therapy include probiotics, psyllium, exercise, melatonin, honey, acu­puncture, and calendula. Therapies that require more research or have been shown to be ineffective include aloe vera, glutamine, and deglyc­yrrhizinated licorice. This article provides an overview of these thera­pies as well as related research and analysis. PMID:25032003

  16. Clinical opportunities in combining immunotherapy with radiation therapy.

    PubMed

    Finkelstein, Steven E; Fishman, Mayer

    2012-01-01

    Preclinical work in murine models suggests that local radiotherapy plus intratumoral syngeneic dendritic cells (DC) injection can mediate immunologic tumor eradication. Radiotherapy affects the immune response to cancer, besides the direct impact on the tumor cells, and other ways to coordinate immune modulation with radiotherapy have been explored. We review here the potential for immune-mediated anticancer activity of radiation on tumors. This can be mediated by differential antigen acquisition and presentation by DC, through changes of lymphocytes' activation, and changes of tumor susceptibility to immune clearance. Recent work has implemented the combination of external beam radiation therapy (EBRT) with intratumoral injection of DC. This included a pilot study of coordinated intraprostatic, autologous DC injection together with radiation therapy with five HLA-A2(+) subjects with high-risk, localized prostate cancer; the protocol used androgen suppression, EBRT (25 fractions, 45 Gy), DC injections after fractions 5, 15, and 25, and then interstitial radioactive implant. Another was a phase II trial using neo-adjuvant apoptosis-inducing EBRT plus intra-tumoral DC in soft tissue sarcoma, to test if this would increase immune activity toward soft tissue sarcoma associated antigens. In the future, radiation therapy approaches designed to optimize immune stimulation at the level of DC, lymphocytes, tumor and stroma effects could be evaluated specifically in clinical trials. PMID:23233905

  17. Endobronchial radiation therapy (EBRT) in the management of lung cancer

    SciTech Connect

    Roach, M. III; Leidholdt, E.M. Jr.; Tatera, B.S.; Joseph, J. )

    1990-06-01

    Between October 1987 and November 1988, 19 endobronchial Iridium-192 line source placements were attempted in 17 patients with advanced incurable lung cancer. Approximately 30 Gy was delivered to the endobronchus using a low dose rate (LDR) afterloading technique delivering a mean dose of 70 cGy/hr at 5 mm. Improvement in subjective symptoms was noted in 67% of evaluable patients whereas objective responses defined by chest X ray and bronchoscopy were noted in 26% and 60%, respectively. No significant morbidity was observed. The radiation exposure to health care workers was low ranging from 10 to 40 mRem per treatment course with most of the staff receiving less than 10 mRem per treatment course (minimal detectable level 10 mRem). The results of this series are compared with selected series using low dose rate as well as intermediate dose rate (IDR) and high dose rate (HDR) endobronchial radiation therapy (EBRT). Based on bronchoscopic responses from the selected series reviewed, both HDR low total dose per treatment (range 7.5-10 Gy) and LDR high total dose per treatment (range 30-50 Gy) are effective in palliating the vast majority of patients with endobronchial lesions. Intermediate dose rate is also effective using fractions similar to high dose rate but total dose similar to low dose rate. The efficacy of endobronchial radiation therapy in the palliative setting suggest a possible role for endobronchial radiation therapy combined with external beam irradiation with or without chemotherapy in the initial management of localized lung cancer. Defining the optimal total dose, dose rate, and the exact role of endobronchial radiation therapy in the management of lung cancer will require large cooperative trials with standardization of techniques and definitions.

  18. Stereotactic radiation therapy for progressive residual pilocytic astrocytomas.

    PubMed

    Lizarraga, Karlo J; Gorgulho, Alessandra; Lee, Steve P; Rauscher, Glenn; Selch, Michael T; DeSalles, Antonio A F

    2012-08-01

    This report shows the results of stereotactic radiation therapy for progressive residual pilocytic astrocytomas. Medical records of patients who had undergone stereotactic radiation therapy for a progressive residual pilocytic astrocytoma were reviewed. Between 1995 and 2010, 12 patients with progression of a residual pilocytic astrocytoma underwent stereotactic radiation therapy at UCLA. Presentation was headache (4), visual defects (3), hormonal disturbances (2), gelastic seizures (2) and ataxia (1). MRI showed a cystic (9), mixed solid/cystic (2) or solid tumor (1); located in the hypothalamus (5), midbrain (3), thalamus (2), optic chiasm (1) or deep cerebellum (1). Median age was 21 years (range 5-41). Nine tumors received stereotactic radiotherapy (SRT). Three tumors received stereotactic radiosurgery (SRS), two of them to their choline positive regions. SRT median total dose was 50.4 Gy (40-50.4 Gy) in a median of 28 fractions (20-28), using a median fraction dose of 1.8 Gy (1.8-2 Gy) to a median target volume of 6.5 cm(3). (2.4-33.57 cm(3)) SRS median dose was 18.75 Gy (16.66-20 Gy) to a median target volume of 1.69 cm(3) (0.74-2.22 cm(3)). Median follow-up time was 37.5 months. Actuarial long-term progression-free and disease-specific survival probabilities were 73.3 and 91.7 %, respectively. No radiation-induced complications were observed. Stereotactic radiation therapy is a safe and effective modality to control progressive residual pilocytic astrocytomas. Better outcomes are obtained with SRT to entire tumor volumes than with SRS targeting choline positive tumor regions. PMID:22644536

  19. Favre-Racouchot syndrome associated with radiation therapy

    SciTech Connect

    Friedman, S.J.; Su, W.P.

    1983-03-01

    A 56-year-old woman developed Favre-Racouchot syndrome involving her face and scalp primarily at the sites of x-ray irradiation for therapy of an astrocytoma. The patient had not had comedones prior to radiotherapy and did not have a history of excessive sun exposure. The patient showed an excellent response to topical retinoic acid gel. To the best of our knowledge, this is the first case of Favre-Racouchot syndrome developing after radiation therapy to be reported in the literature; its pathogenesis is discussed in this paper.

  20. 21 CFR 892.5710 - Radiation therapy beam-shaping block.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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  1. 21 CFR 892.5710 - Radiation therapy beam-shaping block.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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  2. 21 CFR 892.5770 - Powered radiation therapy patient support assembly.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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  3. 21 CFR 892.5710 - Radiation therapy beam-shaping block.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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  4. 21 CFR 892.5770 - Powered radiation therapy patient support assembly.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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  5. 21 CFR 892.5770 - Powered radiation therapy patient support assembly.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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  6. 21 CFR 892.5710 - Radiation therapy beam-shaping block.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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  7. 21 CFR 892.5900 - X-ray radiation therapy system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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  8. 21 CFR 892.5900 - X-ray radiation therapy system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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  9. 21 CFR 892.5900 - X-ray radiation therapy system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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  10. 21 CFR 892.5770 - Powered radiation therapy patient support assembly.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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  11. 21 CFR 892.5710 - Radiation therapy beam-shaping block.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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  12. 21 CFR 892.5770 - Powered radiation therapy patient support assembly.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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  13. 21 CFR 892.5900 - X-ray radiation therapy system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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  14. 21 CFR 892.5900 - X-ray radiation therapy system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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  15. Radiation therapy for advanced gastric cancer

    SciTech Connect

    Tsukiyama, I.; Akine, Y.; Kajiura, Y.; Ogino, T.; Yamashita, K.; Egawa, S.; Hijikata, J.; Kitagawa, T.

    1988-07-01

    A retrospective study of 75 patients with advanced inoperable gastric cancers, referred to the National Cancer Center Hospital between 1962 and 1982, was performed. According to the Borrmann classification based on X ray findings, Type 1 was found in 3 patients, Type 2 in 5, Type 3 in 40, and Type 4 in 15. Twelve patients could not be classified. The histological type was papillary adenocarcinoma in 7 patients, tubular adenocarcinoma in 23, mucinous carcinoma in 6, poorly differentiated adenocarcinoma in 14, signet ring cell carcinoma in 12 and others in 13. The site of remote metastasis in 19 patients was Virchow's lymph node in 8 patients, Douglas pouch in 3, liver and lung in 2 each and others in 4. All patients were treated by a either telecobalt 60 unit or a linear accelerator using 6 Mv photon and the total dose to primary lesion was 4000 cGy in 5 weeks to 7000 cGy in 8-9 weeks. Complete response (CR) was achieved in 6 patients or 8.0%, partial response (PR) in 46 or 61.3%, and no change (NC) in 23 or 30.7%. The response rate based on the sum of CR and PR was about 70%. The 50% survival period in months was 26.5, 7.3, and 3.2, respectively for patients with CR, PR, and NC. For the response of advanced gastric cancer to chemotherapy in the National Cancer Center Hospital, the combined use of UFT and Mitomycin C gave the highest rate, 46%. As for as local response is concerned, the response rate to radiation was 70%, a better result than that of chemotherapy alone.

  16. Strategies for combining immunotherapy with radiation for anticancer therapy.

    PubMed

    Seyedin, Steven N; Schoenhals, Jonathan E; Lee, Dean A; Cortez, Maria A; Wang, Xiaohong; Niknam, Sharareh; Tang, Chad; Hong, David S; Naing, Aung; Sharma, Padmanee; Allison, James P; Chang, Joe Y; Gomez, Daniel R; Heymach, John V; Komaki, Ritsuko U; Cooper, Laurence J; Welsh, James W

    2015-01-01

    Radiation therapy controls local disease but also prompts the release of tumor-associated antigens and stress-related danger signals that primes T cells to promote tumor regression at unirradiated sites known as the abscopal effect. This may be enhanced by blocking inhibitory immune signals that modulate immune activity through a variety of mechanisms. Indeed, abscopal responses have occurred in patients with lung cancer or melanoma when given anti-CTLA4 antibody and radiation. Other approaches involve expanding and reinfusing T or NK cells or engineered T cells to express receptors that target specific tumor peptides. These approaches may be useful for immunocompromised patients receiving radiation. Preclinical and clinical studies are testing both immune checkpoint-based strategies and adoptive immunotherapies with radiation. PMID:26310908

  17. Detection of High-Risk Atherosclerotic Plaque

    PubMed Central

    Fleg, Jerome L.; Stone, Gregg W.; Fayad, Zahi A.; Granada, Juan F.; Hatsukami, Thomas S.; Kolodgie, Frank D.; Ohayon, Jacques; Pettigrew, Roderic; Sabatine, Marc S.; Tearney, Guillermo; Waxman, Sergio; Domanski, Michael J.; Srinivas, Pothur R.; Narula, Jagat

    2013-01-01

    The leading cause of major morbidity and mortality in most countries around the world is atherosclerotic cardiovascular disease, most commonly caused by thrombotic occlusion of a high-risk coronary plaque resulting in myocardial infarction or cardiac death, or embolization from a high-risk carotid plaque resulting in stroke. The lesions prone to result in such clinical events are termed vulnerable or high-risk plaques, and their identification may lead to the development of pharmacological and mechanical intervention strategies to prevent such events. Autopsy studies from patients dying of acute myocardial infarction or sudden death have shown that such events typically arise from specific types of atherosclerotic plaques, most commonly the thin-cap fibroatheroma. However, the search in human beings for vulnerable plaques before their becoming symptomatic has been elusive. Recently, the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study demonstrated that coronary plaques that are likely to cause future cardiac events, regardless of angiographic severity, are characterized by large plaque burden and small lumen area and/or are thin-cap fibroatheromas verified by radiofrequency intravascular ultrasound imaging. This study opened the door to identifying additional invasive and noninvasive imaging modalities that may improve detection of high-risk atherosclerotic lesions and patients. Beyond classic risk factors, novel biomarkers and genetic profiling may identify those patients in whom noninvasive imaging for vulnerable plaque screening, followed by invasive imaging for risk confirmation is warranted, and in whom future pharmacological and/or device-based focal or regional therapies may be applied to improve long-term prognosis. PMID:22974808

  18. Predictive factors for acute radiation pneumonitis in postoperative intensity modulated radiation therapy and volumetric modulated arc therapy of esophageal cancer

    PubMed Central

    Zhao, Yaqin; Chen, Lu; Zhang, Shu; Wu, Qiang; Jiang, Xiaoqin; Zhu, Hong; Wang, Jin; Li, Zhiping; Xu, Yong; Zhang, Ying Jie; Bai, Sen; Xu, Feng

    2015-01-01

    Background Radiation pneumonitis (RP) is a common side reaction in radiotherapy for esophageal cancer. There are few reports about RP in esophageal cancer patients receiving postoperative intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). This study aims to analyze clinical or dosimetric factors associated with RP, and provides data for radiotherapy planning. Methods We reviewed 68 postoperative esophageal cancer patients who were treated with radiotherapy at the West China Hospital from October 2010 to November 2012 to identify any correlation between the clinical or dosimetric parameters and acute radiation pneumonitis (ARP) or severe acute radiation pneumonitis (SARP) by t-test, chi-square test, and logistic regression analysis. Results Of the 68 patients, 33 patients (48.5%) developed ARP, 13 of which (19.1%) developed SARP. Of these 33 patients, 8 (11.8%), 12 (17.6%), 11 (16.2%), and 2 (2.9%) patients were grade 1, 2, 3, and 4 ARP, respectively. Univariate analysis showed that lung infection during radiotherapy, use of VMAT, mean lung dose (MLD), and dosimetric parameters (e.g. V20, V30) are significantly correlated with RP. Multivariate analysis found that lung infection during radiotherapy, MLD ≥ 12 Gy, and V30 ≥ 13% are significantly correlated with an increased risk of RP. Conclusion Lung infection during radiotherapy and low radiation dose volume distribution were predictive factors associated with RP and should be accounted for during radiation planning. PMID:26273335

  19. Gold nanoparticles and their alternatives for radiation therapy enhancement

    PubMed Central

    Cooper, Daniel R.; Bekah, Devesh; Nadeau, Jay L.

    2014-01-01

    Radiation therapy is one of the most commonly used treatments for cancer. The dose of delivered ionizing radiation can be amplified by the presence of high-Z materials via an enhancement of the photoelectric effect; the most widely studied material is gold (atomic number 79). However, a large amount is needed to obtain a significant dose enhancement, presenting a challenge for delivery. In order to make this technique of broader applicability, the gold must be targeted, or alternative formulations developed that do not rely solely on the photoelectric effect. One possible approach is to excite scintillating nanoparticles with ionizing radiation, and then exploit energy transfer between these particles and attached dyes in a manner analogous to photodynamic therapy (PDT). Doped rare-earth halides and semiconductor quantum dots have been investigated for this purpose. However, although the spectrum of emitted light after radiation excitation is usually similar to that seen with light excitation, the yield is not. Measurement of scintillation yields is challenging, and in many cases has been done only for bulk materials, with little understanding of how the principles translate to the nanoscale. Another alternative is to use local heating using gold or iron, followed by application of ionizing radiation. Hyperthermia pre-sensitizes the tumors, leading to an improved response. Another approach is to use chemotherapeutic drugs that can radiosensitize tumors. Drugs may be attached to high-Z nanoparticles or encapsulated. This article discusses each of these techniques, giving an overview of the current state of nanoparticle-assisted radiation therapy and future directions. PMID:25353018

  20. Immune effects of targeted radiation therapy for cancer.

    PubMed

    Sridharan, Vishwajith; Schoenfeld, Jonathan D

    2015-03-01

    Radiation therapy plays an important role in the treatment of the majority of cancers, and is commonly used to treat both localized and metastatic disease. Immunotherapy has recently been firmly integrated into the treatment of metastatic melanoma, and holds significant promise in treating a variety of other cancers. Although large field radiation has historically been appreciated for its immunosuppressive ability, targeted radiation can induce substantial changes in the tumor microenvironment beyond cellular cytotoxicity that evoke innate and adaptive immune responses. Previous studies have highlighted radiation-induced changes in proinflammatory cytokines, chemokines, effector, and immunosuppressive T cell subsets, as well as in immune receptors on tumor cells. Some of these changes in localized and systemic immune mediators have been linked to expansion of tumor-reactive T cells, improved clinical responses, and increased overall survival in preclinical and clinical models. Taken together, this evidence suggests that targeted radiation therapy can impact anti-tumor immune responses, and may potentially be combined with immunotherapy for synergistic effect. PMID:25828526

  1. Radiation therapy in the treatment of metastatic renal cell carcinoma

    SciTech Connect

    Onufrey, V.; Mohiuddin, M.

    1985-11-01

    Adenocarcinoma of the kidney is an unusual tumor, both in its biological behavior and in its response to radiation treatment. Historically, these tumors have been considered to be radioresistant, and the role of radiation therapy remains questionable in the primary management of this disease. However, radiation treatment is routinely used in the palliation of metastatic lesions for relief of symptoms. Therefore, we have undertaken a review of our experience in the treatment of this disease to determine the effectiveness of radiation in its palliation. From 1956 to 1981, 125 patients with metastatic lesions from hypernephroma have been treated in the Department of Radiation Therapy at Thomas Jefferson University Hospital. Most patients were referred for relief of bone pain (86), brain metastasis (12), spinal cord compression (9), and soft tissue masses (18). Total doses varied from 2000 rad to a maximum of 6000 rad. Response to treatment was evaluated on the basis of relief of symptoms, either complete, partial or no change. Our results indicate a significantly higher response rate of 65% for total doses equal to or greater than a TDF of 70, as compared to 25% for doses lower than a TDF of 70. No difference in response was observed either for bone or soft tissue metastasis or visceral disease. This leads us to believe that metastatic lesions from adenocarcinomas of the kidney should be treated to higher doses to obtain maximum response rates. Analysis of these results are presented in detail.

  2. Role of radiation therapy in the treatment of olfactory neuroblastoma

    SciTech Connect

    Ahmad, K.; Fayos, J.V.

    1980-03-01

    Nine patients with olfactory neuroblastoma were treated at the Radiation Therapy Service of the University of Michigan Medical Center (UMMC); their case histories are presented. There was a slight female predominance and the peak age distribution was between 60 to 69 years (4 patients). One patient developed sudden visual loss in one eye and partial loss in the other resulting from a hematoma at the optic chiasmal region. We have ascribed it to radiation damage. Our results show that this tumor is radiocontrollable; control at primary site occurs in 66.6% of patients. We recommend postoperative irradiation in all tumors that are extensive initially.

  3. Adeno-associated Virus Gene Therapy With Cholesterol 24-Hydroxylase Reduces the Amyloid Pathology Before or After the Onset of Amyloid Plaques in Mouse Models of Alzheimer's Disease

    PubMed Central

    Hudry, Eloise; Van Dam, Debby; Kulik, Wim; De Deyn, Peter P; Stet, Femke S; Ahouansou, Ornella; Benraiss, Abdellatif; Delacourte, André; Bougnères, Pierre; Aubourg, Patrick; Cartier, Nathalie

    2009-01-01

    The development of Alzheimer's disease (AD) is closely connected with cholesterol metabolism. Cholesterol increases the production and deposition of amyloid-β (Aβ) peptides that result in the formation of amyloid plaques, a hallmark of the pathology. In the brain, cholesterol is synthesized in situ but cannot be degraded nor cross the blood–brain barrier. The major exportable form of brain cholesterol is 24S-hydroxycholesterol, an oxysterol generated by the neuronal cholesterol 24-hydroxylase encoded by the CYP46A1 gene. We report that the injection of adeno-associated vector (AAV) encoding CYP46A1 in the cortex and hippocampus of APP23 mice before the onset of amyloid deposits markedly reduces Aβ peptides, amyloid deposits and trimeric oligomers at 12 months of age. The Morris water maze (MWM) procedure also demonstrated improvement of spatial memory at 6 months, before the onset of amyloid deposits. AAV5-wtCYP46A1 vector injection in the cortex and hippocampus of amyloid precursor protein/presenilin 1 (APP/PS) mice after the onset of amyloid deposits also reduced markedly the number of amyloid plaques in the hippocampus, and to a less extent in the cortex, 3 months after the injection. Our data demonstrate that neuronal overexpression of CYP46A1 before or after the onset of amyloid plaques significantly reduces Aβ pathology in mouse models of AD. PMID:19654569

  4. [Efficacy of Radiation Therapy for Esophageal Cancer with Bone Metastases].

    PubMed

    Katayanagi, So; Watanabe, Takafumi; Makuuchi, Yosuke; Shigoka, Masatoshi; Sumi, Tetsuo; Takagaki, Shinichi; Okubo, Mitsuru; Tachibana, Shingo; Oosaka, Yoshiaki; Tsuchida, Akihiko; Kawachi, Shigeyuki

    2015-11-01

    We retrospectively considered the validity of radiotherapy for patients with bone metastases from esophageal cancer. Eight patients have received radiotherapy in our hospital since 2007. The median age of the patients was 63 years, with 5 men and 3 women. Bone metastatic sites were 4 to the vertebrae, 3 to the ribs, 3 to the femur and 1 each to the humerus, ulna, and radius, respectively. All of the patients had other unresectable sites of metastasis. Radiotherapy reduced pain of 3 patients of PS 1 clearly. Median survival time from the start of radiation therapy was 50 days. When PS was relatively good, the possibility of easing pain and improving QOL was suggested by our data. There is a possibility that radiation therapy for patients with bone metastases from esophageal cancer can improve the QOL and alleviate pain. PMID:26805091

  5. Adaptive and robust radiation therapy in the presence of drift

    NASA Astrophysics Data System (ADS)

    Mar, Philip Allen; Chan, Timothy C. Y.

    2015-05-01

    Combining adaptive and robust optimization in radiation therapy has the potential to mitigate the negative effects of both intrafraction and interfraction uncertainty over a fractionated treatment course. A previously developed adaptive and robust radiation therapy (ARRT) method for lung cancer was demonstrated to be effective when the sequence of breathing patterns was well-behaved. In this paper, we examine the applicability of the ARRT method to less well-behaved breathing patterns. We develop a novel method to generate sequences of probability mass functions that represent different types of drift in the underlying breathing pattern. Computational results derived from applying the ARRT method to these sequences demonstrate that the ARRT method is effective for a much broader class of breathing patterns than previously demonstrated.

  6. Impact of dose calculation algorithm on radiation therapy

    PubMed Central

    Chen, Wen-Zhou; Xiao, Ying; Li, Jun

    2014-01-01

    The quality of radiation therapy depends on the ability to maximize the tumor control probability while minimize the normal tissue complication probability. Both of these two quantities are directly related to the accuracy of dose distributions calculated by treatment planning systems. The commonly used dose calculation algorithms in the treatment planning systems are reviewed in this work. The accuracy comparisons among these algorithms are illustrated by summarizing the highly cited research papers on this topic. Further, the correlation between the algorithms and tumor control probability/normal tissue complication probability values are manifested by several recent studies from different groups. All the cases demonstrate that dose calculation algorithms play a vital role in radiation therapy. PMID:25431642

  7. Orbital lymphomas and pseudolymphomas: Treatment with radiation therapy

    SciTech Connect

    Gordon, P.S.; Juillard, G.J.F.; Selch, M.T.; Parker, R.G.; Fu, Y.

    1986-06-01

    A retrospective analysis of 16 patients with orbital lymphoma or pseudolymphoma from 1961-1984 was undertaken to evaluate the use of radiation therapy. Pathologic assessment confirmed that four patients had benign pseudolymphoma, and 12 patients had true malignant lymphoma, including two with advanced disease at presentation. With a median follow-up of 4 years, the local control rate with radiation therapy was 100%, although the two patients with advanced disease died of lymphoma 26-33 months after irradiation. While doses of 1,600-2,000 cGy appear adequate for pseudolymphoma, for lymphoma a dose of 3,000-4,000 cGy is necessary. Subconjunctival lesions can be treated in a single anteroposterior field; retroorbital lesions require an additional lateral field.

  8. The effects of a weekly radiation therapy newsletter on patients.

    PubMed

    Hagopian, G A

    1991-01-01

    The purpose of this study was to investigate the effects that structured patient educational information in the form of a weekly newsletter has on the knowledge, side effects, and self-care behaviors of patients with cancer who are undergoing radiation therapy. It was hypothesized that subjects reading the newsletter would know more about radiation therapy and its side effects than subjects not reading the newsletter and, therefore, would employ more self-care behaviors, resulting in less severe side effects. A post-test-only control group design was used. Although the subjects who read the newsletter scored significantly higher on the knowledge test, there were no significant differences in the helpfulness or number of self-care behaviors or in the severity of side effects. Patient education in the form of a newsletter may provide benefits to patients other than knowledge (e.g., reduced anxiety) that may be just as important as side effects relief. PMID:1945966

  9. Sick sinus syndrome as a complication of mediastinal radiation therapy

    SciTech Connect

    Pohjola-Sintonen, S.; Toetterman, K.J.K.; Kupari, M. )

    1990-06-01

    A 33-year-old man who had received mediastinal radiation therapy for Hodgkin's disease 12 years earlier developed a symptomatic sick sinus syndrome requiring the implantation of a permanent pacemaker. The sick sinus syndrome and a finding of an occult constrictive pericarditis were considered to be due to the previous mediastinal irradiation. A ventricular pacemaker was chosen because mediastinal radiotherapy also increases the risk of developing atrioventricular conduction defects.

  10. Successful Treatment of Occipital Radiating Headache Using Pulsed Radiofrequency Therapy

    PubMed Central

    Lee, Sun Yeul; Jang, Dae Il; Noh, Chan

    2015-01-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease involving multiple joints. The cervical spine is often affected, and cases involving atlantoaxial joint can lead to instability. Anterior atlantoaxial subluxation in RA patients can lead to posterior neck pain or occipital headache because of compression of the C2 ganglion or nerve. Here, we report the successful treatment of a RA patient with occipital radiating headache using pulsed radiofrequency therapy at the C2 dorsal root ganglion. PMID:26279821

  11. Massive osteolysis of the right clavicle developing after radiation therapy

    SciTech Connect

    Skinner, W.L.; Buzdar, A.U.; Libshitz, H.I.

    1988-07-15

    This report describes an unusual case of clavicular osteolysis, a late complication of radiation therapy for breast cancer, and demonstrates the diagnostic implications that radiotherapy changes can pose. Radiotherapy to the chest wall produces a spectrum of alterations in bone over time, ranging from early roentgenographic findings of osteoporosis and trabecular thickening to spontaneous fractures and changes that may be confused with metastatic disease or postirradiation sarcoma.

  12. Stereotactic Body Radiation Therapy for Treatment of Spinal Bone Metastasis.

    PubMed

    Cihan, Yasemin Benderli

    2016-01-01

    Stereotactic body radiation therapy (SBRT) appears an effective and safe treatment modality for spinal bone metastasis, which can enhance local control and improve quality of life. Life expectation, predicted fracture risk, localization, quality, size and number of metastasis and presence or absence of nerve compression seem to be important factors in decision-making for treatment. Further studies are needed to identify subsets of patient which will most benefit from treatment. PMID:27039816

  13. ReVOLT: radiation-enhanced viral oncolytic therapy

    SciTech Connect

    Advani, Sunil J.; Mezhir, James J.; Roizman, Bernard; Weichselbaum, Ralph R. . E-mail: rrw@rover.uchicago.edu

    2006-11-01

    Viral oncolytic therapy has been pursued with renewed interest as the molecular basis of carcinogenesis and viral replication has been elucidated. Genetically engineered, attenuated viruses have been rationally constructed to achieve a therapeutic index in tumor cells compared with surrounding normal tissue. Many of these attenuated mutant viruses have entered clinical trials. Here we review the preclinical literature demonstrating the interaction of oncolytic viruses with ionizing radiation and provides a basis for future clinical trials.

  14. Adaptive radiation therapy of prostate cancer

    NASA Astrophysics Data System (ADS)

    Wen, Ning

    ART is a close-loop feedback algorithm which evaluates the organ deformation and motion right before the treatment and takes into account dose delivery variation daily to compensate for the difference between planned and delivered dose. It also has potential to allow further dose escalation and margin reduction to improve the clinical outcome. This retrospective study evaluated ART for prostate cancer treatment and radiobiological consequences. An IRB approved protocol has been used to evaluate actual dose delivery of patients with prostate cancer undergoing treatment with daily CBCT. The dose from CBCT was measured in phantom using TLD and ion chamber techniques in the pelvic scan setting. There were two major findings from the measurements of CBCT dose: (1) the lateral dose distribution was not symmetrical, with Lt Lat being ˜40% higher than Rt Lat and (2) AP skin dose varies with patient size, ranging 3.2--6.1 cGy for patient's AP separation of 20--33 cm (the larger the separation, the less the skin dose) but lateral skin doses depend little on separations. Dose was recalculated on each CBCT set under the same treatment plan. DIR was performed between SIM-CT and evaluated for each CT sets. Dose was reconstructed and accumulated to reflect the actual dose delivered to the patient. Then the adaptive plans were compared to the original plan to evaluate tumor control and normal tissue complication using radiobiological model. Different PTV margins were also studied to access margin reduction techniques. If the actual dose delivered to the PTV deviated significantly from the prescription dose for the given fractions or the OAR received higher dose than expected, the treatment plan would be re-optimized based on the previously delivered dose. The optimal schedule was compared based on the balance of PTV dose coverage and inhomogeneity, OAR dose constraints and labor involved. DIR was validated using fiducial marker position, visual comparison and UE. The mean and standard deviation of markers after rigid registration in L-R direction was 0 and 1 mm. But the mean was 2--4 mm in the A-P and S-I direction and standard deviation was about 2 mm. After DIR, the mean in all three directions became 0 and standard deviation was within sub millimeter. UE images were generated for each CT set and carefully reviewed in the prostate region. DIR provided accurate transformation matrix to be used for dose reconstruction. The delivered dose was evaluated with radiobiological models. TCP for the CTV was calculated to evaluate tumor control in different margin settings. TCP calculated from the reconstructed dose agreed within 5% of the value in the plan for all patients with three different margins. EUD and NTCP were calculated to evaluate reaction of rectum to radiation. Similar biological evaluation was performed for bladder. EUD of actual dose was 3%--9% higher than that of planned dose of patient 1--3, 11%--20% higher of patient 4--5. Smaller margins could not reduce late GU toxicity effectively since bladder complication was directly related to Dmax which was at the same magnitude in the bladder no matter which margin was applied. Re-optimization was performed at the 10th, 20th , 30th, and 40th fraction to evaluate the effectiveness to limit OAR dose while maintaining the target coverage. Reconstructed dose was added to dose from remaining fractions after optimization to show the total dose patient would receive. It showed that if the plan was re-optimized at 10th or 20th fraction, total dose to rectum and bladder were very similar to planned dose with minor deviations. If the plan was re-optimized at the 30th fraction, since there was a large deviation between reconstructed dose and planned dose to OAR, optimization could not limit the OAR dose to the original plan with only 12 fractions left. If the re-optimization was done at the 40th fraction, it was impossible to compensate in the last 2 fractions. Large deviations of total dose to bladder and rectum still existed while dose inhomogeneity to PTV was significantly increased due to hard constraints set in the optimization to reduce OAR dose. In summary, ART did not show improvements in TCP if the patient was setup with CBCT. However, EUD of rectum and bladder was increased significantly due to tissue deformation which varied daily. With the power of ART, margins added to the CTV could be further reduced to preserve critical organs surrounding the target. (Abstract shortened by UMI.)

  15. Boron neutron capture therapy (BNCT): A radiation oncology perspective

    SciTech Connect

    Dorn, R.V. III Idaho National Engineering Lab., Idaho Falls, ID )

    1994-03-30

    Boron neutron capture therapy (BNCT) offers considerable promise in the search for the ideal cancer therapy, a therapy which selectively and maximally damages malignant cells while sparing normal tissue. This bimodal treatment modality selectivity concentrates a boron compound in malignant cells, and then [open quotes]activates[close quotes] this compound with slow neutrons resulting in a highly lethal event within the cancer cell. This article reviews this treatment modality from a radiation oncology, biology, and physics perspective. The remainder of the articles in this special issue provide a survey of the current [open quotes]state-of-the-art[close quotes] in this rapidly expanding field, including information with regard to boron compounds and their localization. 118 refs., 3 figs.

  16. Approaching oxygen-guided intensity-modulated radiation therapy

    PubMed Central

    Epel, Boris; Redler, Gage; Pelizzari, Charles; Tormyshev, Victor M.; Halpern, Howard J.

    2016-01-01

    The outcome of cancer radiation treatment is strongly correlated with tumor oxygenation. The aim of this study is to use oxygen tension distributions in tumors obtained using Electron Paramagnetic Resonance (EPR) imaging to devise better tumor radiation treatment. The proposed radiation plan is delivered in two steps. In the first step, a uniform 50% tumor control dose (TCD50) is delivered to the whole tumor. For the second step an additional dose boost is delivered to radioresistant, hypoxic tumor regions. FSa fibrosarcomas grown in the gastrocnemius of the legs of C3H mice were used. Oxygen tension images were obtained using a 250 MHz pulse imager and injectable partially deuterated trityl OX63 (OX71) spin probe. Radiation was delivered with a novel animal intensity modulated radiation therapy (IMRT) XRAD225Cx microCT/radiation therapy delivery system. In a simplified scheme for boost dose delivery, the boost area is approximated by a sphere, whose radius and position are determined using an EPR O2 image. The sphere that irradiates the largest fraction of hypoxic voxels in the tumor was chosen using an algorithm based on Receiver Operator Characteristic (ROC) analysis. We used the fraction of irradiated hypoxic volume as the true positive determinant and the fraction of irradiated normoxic volume as the false positive determinant in the terms of that analysis. The most efficient treatment is the one that demonstrates the shortest distance from the ROC curve to the upper left corner of the ROC plot. The boost dose corresponds to the difference between TCD90 and TCD50 values. For the control experiment an identical radiation dose to the normoxic tumor area is delivered. PMID:26782211

  17. Ultrasound Imaging in Radiation Therapy: From Interfractional to Intrafractional Guidance

    PubMed Central

    Western, Craig; Hristov, Dimitre

    2015-01-01

    External beam radiation therapy (EBRT) is included in the treatment regimen of the majority of cancer patients. With the proliferation of hypofractionated radiotherapy treatment regimens, such as stereotactic body radiation therapy (SBRT), interfractional and intrafractional imaging technologies are becoming increasingly critical to ensure safe and effective treatment delivery. Ultrasound (US)-based image guidance systems offer real-time, markerless, volumetric imaging with excellent soft tissue contrast, overcoming the limitations of traditional X-ray or computed tomography (CT)-based guidance for abdominal and pelvic cancer sites, such as the liver and prostate. Interfractional US guidance systems have been commercially adopted for patient positioning but suffer from systematic positioning errors induced by probe pressure. More recently, several research groups have introduced concepts for intrafractional US guidance systems leveraging robotic probe placement technology and real-time soft tissue tracking software. This paper reviews various commercial and research-level US guidance systems used in radiation therapy, with an emphasis on hardware and software technologies that enable the deployment of US imaging within the radiotherapy environment and workflow. Previously unpublished material on tissue tracking systems and robotic probe manipulators under development by our group is also included. PMID:26180704

  18. Ultrasound Imaging in Radiation Therapy: From Interfractional to Intrafractional Guidance.

    PubMed

    Western, Craig; Hristov, Dimitre; Schlosser, Jeffrey

    2015-06-01

    External beam radiation therapy (EBRT) is included in the treatment regimen of the majority of cancer patients. With the proliferation of hypofractionated radiotherapy treatment regimens, such as stereotactic body radiation therapy (SBRT), interfractional and intrafractional imaging technologies are becoming increasingly critical to ensure safe and effective treatment delivery. Ultrasound (US)-based image guidance systems offer real-time, markerless, volumetric imaging with excellent soft tissue contrast, overcoming the limitations of traditional X-ray or computed tomography (CT)-based guidance for abdominal and pelvic cancer sites, such as the liver and prostate. Interfractional US guidance systems have been commercially adopted for patient positioning but suffer from systematic positioning errors induced by probe pressure. More recently, several research groups have introduced concepts for intrafractional US guidance systems leveraging robotic probe placement technology and real-time soft tissue tracking software. This paper reviews various commercial and research-level US guidance systems used in radiation therapy, with an emphasis on hardware and software technologies that enable the deployment of US imaging within the radiotherapy environment and workflow. Previously unpublished material on tissue tracking systems and robotic probe manipulators under development by our group is also included. PMID:26180704

  19. Analytical probabilistic modeling for radiation therapy treatment planning.

    PubMed

    Bangert, Mark; Hennig, Philipp; Oelfke, Uwe

    2013-08-21

    This paper introduces the concept of analytical probabilistic modeling (APM) to quantify uncertainties in quality indicators of radiation therapy treatment plans. Assuming Gaussian probability densities over the input parameters of the treatment plan quality indicators, APM enables the calculation of the moments of the induced probability density over the treatment plan quality indicators by analytical integration. This paper focuses on analytical probabilistic dose calculation algorithms and the implications of APM regarding treatment planning. We derive closed-form expressions for the expectation value and the (co)variance of (1) intensity-modulated photon and proton dose distributions based on a pencil beam algorithm and (2) the standard quadratic objective function used in inverse planning. Complex correlation models of high dimensional uncertain input parameters and the different nature of random and systematic uncertainties in fractionated radiation therapy are explicitly incorporated into APM. APM variance calculations on phantom data sets show that the correlation assumptions and the difference of random and systematic uncertainties of the input parameters have a crucial impact on the uncertainty of the resulting dose. The derivations regarding the quadratic objective function show that APM has the potential to enable robust planning at almost the same computational cost like conventional inverse planning after a single probabilistic dose calculation. Beneficial applications of APM in the context of radiation therapy treatment planning are feasible. PMID:23877218

  20. Analytical probabilistic modeling for radiation therapy treatment planning

    NASA Astrophysics Data System (ADS)

    Bangert, Mark; Hennig, Philipp; Oelfke, Uwe

    2013-08-01

    This paper introduces the concept of analytical probabilistic modeling (APM) to quantify uncertainties in quality indicators of radiation therapy treatment plans. Assuming Gaussian probability densities over the input parameters of the treatment plan quality indicators, APM enables the calculation of the moments of the induced probability density over the treatment plan quality indicators by analytical integration. This paper focuses on analytical probabilistic dose calculation algorithms and the implications of APM regarding treatment planning. We derive closed-form expressions for the expectation value and the (co)variance of (1) intensity-modulated photon and proton dose distributions based on a pencil beam algorithm and (2) the standard quadratic objective function used in inverse planning. Complex correlation models of high dimensional uncertain input parameters and the different nature of random and systematic uncertainties in fractionated radiation therapy are explicitly incorporated into APM. APM variance calculations on phantom data sets show that the correlation assumptions and the difference of random and systematic uncertainties of the input parameters have a crucial impact on the uncertainty of the resulting dose. The derivations regarding the quadratic objective function show that APM has the potential to enable robust planning at almost the same computational cost like conventional inverse planning after a single probabilistic dose calculation. Beneficial applications of APM in the context of radiation therapy treatment planning are feasible.

  1. Biological predictors of cervical cancer response to radiation therapy.

    PubMed

    Klopp, Ann H; Eifel, Patricia J

    2012-04-01

    The addition of cisplatin-based chemotherapy to standard radiation therapy reduces the risk of recurrence and disease-related death rates from locally advanced cervical cancers by as much as 50%. However, the absolute gains are relatively small for patients with early tumors, many of whom would have been cured with radiation alone, and recurrence rates are still high for patients who have very large or advanced-stage tumors. As a result, there is a pressing need for more accurate predictors of radiocurability. A variety of types of biomarkers have been shown to correlate with cervical cancer response to radiation therapy. These include traditional clinical and morphologic predictors, non-molecular biomarkers, including hypoxia and fluorodeoxyglucose-positron emission tomography (FDG-PET) avidity, as well as molecular biomarkers, which include single-gene markers or array-based multigene predictors. Multi-gene predictors of response remain immature in cervical cancer, but studies thus far have paved the way for future studies to validate these findings. Methods will need to be standardized and markers will need to be validated on homogeneous patient populations and treatment approaches before they can become useful tools for clinical decision making. In addition, new biomarkers will be of major value only if they add to the predictive value of traditional clinical and morphologic predictors. Ultimately, the most useful biomarkers will identify patients who will benefit from specific molecularly targeted agents in addition to radiation therapy or perhaps identify patient who are at low risk for recurrence, for whom the dose of radiation or chemotherapy can be reduced. PMID:22385921

  2. The radiation techniques of tomotherapy & intensity-modulated radiation therapy applied to lung cancer

    PubMed Central

    Zhu, Zhengfei

    2015-01-01

    Radiotherapy (RT) plays an important role in the management of lung cancer. Development of radiation techniques is a possible way to improve the effect of RT by reducing toxicities through better sparing the surrounding normal tissues. This article will review the application of two forms of intensity-modulated radiation therapy (IMRT), fixed-field IMRT and helical tomotherapy (HT) in lung cancer, including dosimetric and clinical studies. The advantages and potential disadvantages of these two techniques are also discussed. PMID:26207214

  3. NEW DEVELOPMENTS IN RADIATION THERAPY FOR HEAD AND NECK CANCER: INTENSITY MODULATED RADIATION THERAPY AND HYPOXIA TARGETING

    PubMed Central

    Lee, Nancy Y.; Le, Quynh-Thu

    2008-01-01

    Intensity modulated radiation therapy (IMRT) has revolutionized radiation treatment for head and neck cancers (HNC). When compared to the traditional techniques, IMRT has the unique ability to minimize the dose delivered to normal tissues without compromising tumor coverage. As a result, side effects from high dose radiation have decreased and patient quality of life has improved. In addition to toxicity reduction, excellent clinical outcomes have been reported for IMRT. The first part of this review will focus on clinical results of IMRT for HNC. Tumor hypoxia or the condition of low oxygen is a key factor for tumor progression and treatment resistance. Hypoxia develops in solid tumors due to aberrant blood vessel formation, fluctuation in blood flow and increasing oxygen demands for tumor growth. Because hypoxic tumor cells are more resistant to ionizing radiation, hypoxia has been a focus of clinical research in radiation therapy for half a decade. Interest for targeting tumor hypoxia have waxed and waned as promising treatments emerged from the laboratory, only to fail in the clinics. However, with the development of new technologies, the prospect of targeting tumor hypoxia is more tangible. The second half of the review will focus on approaches for assessing tumor hypoxia and on the strategies for targeting this important microenvironmental factor in HNC. PMID:18544439

  4. Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT)

    SciTech Connect

    Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham

    2013-12-15

    Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147–53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation to surrounding healthy tissue. A same-subject repeated measures design was used for this study, where five anal carcinoma cases at the Andrew Love Cancer Centre were selected. Conformal and IMRT plans were generated and dosimetric evaluations were performed. Each plan was prescribed a total of 54 Gray (Gy) over a course of 30 fractions to the primary site. The IMRT plans resulted in improved dosimetry to the planning target volume (PTV) and reduction in radiation to the critical structures (bladder, external genitalia and femoral heads). Statistically there was no difference between the IMRT and conformal plans in the dose to the small and large bowel; however, the bowel IMRT dose–volume histogram (DVH) doses were consistently lower. The IMRT plans were superior to the conformal plans with improved dose conformity and reduced radiation to the surrounding healthy tissue. Anecdotally it was found that patients tolerated the IMRT treatment better than the three-dimensional (3D) conformal radiation therapy. This study describes and compares the planning techniques.

  5. Biological plaque control: novel therapeutic approach to periodontal disease.

    PubMed

    Sugano, Naoyuki

    2012-03-01

    Despite its important role in the control of periodontal disease, mechanical plaque control is not properly practiced by most individuals. Therefore, adjunctive chemical plaque control using chlorhexidine and antibiotics has also been suggested as an additional therapeutic strategy to augment mechanical plaque control. However, the additional effects of adjunctive antibiotic therapy are small, and topical chlorhexidine therapy is not without side effects. Given current limitations, new approaches for the control of biofilm are required. The new therapeutic approaches discussed in this review are divided into two categories: probiotics and vaccines. Probiotics is an interesting new field of periodontology research that aims to achieve biological plaque control by eliminating pathogenic bacteria. In addition, passive immunization using egg yolk antibody raised against periodontal pathogens may be an effective approach for the treatment of periodontitis. Further study to evaluate the possible effects of these biological plaque control methods against periodontal disease is warranted. PMID:22466880

  6. Radiation therapy for retinoblastoma: comparison of results with lens-sparing versus lateral beam techniques

    SciTech Connect

    McCormick, B.; Ellsworth, R.; Abramson, D.; Haik, B.; Tome, M.; Grabowski, E.; LoSasso, T.

    1988-09-01

    From 1979 through 1986, 170 children were seen at our institution diagnosed with retinoblastoma. Sixty-six of the children with involvement of 121 eyes, were referred for definitive external beam radiation to one or both eyes. During the study period, two distinct radiation techniques were used. From 1980 through mid-1984, a lens-sparing technique included an anterior electron beam with a contact lens mounted lead shield, combined with a lateral field, was used. Since mid-1984, a modified lateral beam technique has been used, mixing lateral electrons and superior and inferior lateral oblique split beam wedged photons. Doses prescribed were similar for both techniques, ranging from 3,850 to 5,000 cGy in 4 to 5 weeks. The lens-sparing and the modified lateral techniques are compared for local control. For eyes with Group I through III disease, the lens-sparing technique resulted in local control in 33% of the eyes treated, where the modified lateral technique controlled 83% of the eyes treated (p = .006). Mean time to relapse was identical in both groups, that is 24 and 26 months respectively. Most relapses were successfully treated with further local therapy, including laser or cryosurgery, or 60Co plaques. Five eyes required enucleation following initial treatment with the lens-sparing technique, but none thus far with the lateral beam technique. For eyes with Group IV and V disease, no significant differences were found between the two techniques in terms of local control or eventual need for enucleation. With a mean follow-up time of 33 months for the entire group, the 4-year survival is 93%. Two of the 4 deaths are due to second primary tumor, and all 4 have occurred in the lens-sparing group. Because follow-up time is more limited in the lateral beam group, this is not statistically significant and direct survival comparisons are premature.

  7. Scientists Reduce Alzheimer's-Linked Brain Plaques in Mice

    MedlinePlus

    ... html Scientists Reduce Alzheimer's-Linked Brain Plaques in Mice Team used gene therapy, but there's no guarantee ... March 31, 2016 (HealthDay News) -- Scientists working with mice report preliminary progress in efforts to eliminate brain- ...

  8. Improved treatment planning for COMS eye plaques

    SciTech Connect

    Astrahan, Melvin A. . E-mail: astrahan@usc.edu

    2005-03-15

    Purpose: A recent reanalysis of the Collaborative Ocular Melanoma Study (COMS) medium tumor trial concluded that incorporating factors to account for anisotropy, line source approximation, the gold plaque, and attenuation in the Silastic seed carrier into the dose calculations resulted in a significant and consistent reduction of calculated doses to structures of interest within the eye. The authors concluded that future eye plaque dosimetry should be 'performed using the most up-to-date parameters available.' The reason these factors are important is attributable to the low energy {sup 125}I radiation (approximately 28 keV) that is primarily absorbed by the photoelectric process. Photoelectric absorption is quite dependent on the atomic composition of the absorbing material. Being 40% silicon by weight, the effective atomic number of Silastic is significantly greater than that of water. Although the AAPM TG43 brachytherapy formalism inherently addresses the issues of source anisotropy and geometry, its parameter that accounts for scatter and attenuation, the radial dose function g(r), assumes that the source is immersed in infinite homogeneous water. In this work, factors are proposed for {sup 125}I that correct for attenuation in the Silastic carrier and scatter deficits resulting from the gold plaque and nearby air. The implications of using {sup 103}Pd seeds in COMS plaques are also discussed. Methods and materials: An existing TG43-based ophthalmic plaque planning system was modified to incorporate additional scatter and attenuation correction factors that better account for the path length of primary radiation in the Silastic seed carrier and the distance between the dose calculation point and the eye-air interface. Results: Compared with homogeneous water, the dose-modifying effects of the Silastic and gold are greatest near the plaque surface and immediately adjacent to the plaque, while being least near the center of the eye. The calculated dose distribution surrounding a single {sup 125}I seed centered in a COMS 20 mm plaque was found to be consistent with previously published examples that used thermoluminescent dosimetry measurements and Monte Carlo methods. For fully loaded 12 and 20 mm plaques, calculated dose to critical ocular structures ranged from 16%-50% less than would have been reported using the standard COMS dose calculation protocol. Conclusions: Treatment planning for COMS eye plaques that accurately accounts for the presence of the gold, Silastic and extraocular air is both possible and practical.

  9. Varicella zoster virus rhombencephalomyelitis following radiation therapy for oropharyngeal carcinoma.

    PubMed

    Prelack, Marisa S; Patterson, Kristina R; Berger, Joseph R

    2016-03-01

    We report a 64-year-old man with a history of stage IV oropharyngeal squamous cell carcinoma treated with cisplatin and cetuximab followed by radiation therapy who developed a rapidly advancing rhombencephalomyelitis 11months after the completion of radiation to the base of his tongue. His initial symptoms were left ear paresthesias, dysphagia, and progressive descending weakness. Routine cerebrospinal fluid (CSF) analysis was unremarkable. Initial MRI of the brain and cervical spinal cord revealed a demarcated symmetrical heterogeneously enhancing intramedullary lesion involving the cervicomedullary spinal cord. Progressive neurological worsening included increasing weakness of his limbs, facial weakness and ocular motility disorders and MRI revealed that the lesion was advancing into his pons and cervical spinal cord. Empiric treatment for radiation myelitis was initiated. Although CSF polymerase chain reaction was negative for varicella zoster virus (VZV), antibody studies revealed intrathecal synthesis of antibody to VZV and treatment for VZV was started as well. Improvement was slow and incomplete with subsequent worsening resulting in death in 5.5weeks. The diagnosis of rhombencephalitis and myelitis following radiation therapy may be exquisitely challenging. The possibility of VZV, a treatable disorder, should be included in the differential diagnosis. PMID:26602800

  10. Aesthetic results following partial mastectomy and radiation therapy

    SciTech Connect

    Matory, W.E. Jr.; Wertheimer, M.; Fitzgerald, T.J.; Walton, R.L.; Love, S.; Matory, W.E.

    1990-05-01

    This study was undertaken to determine the aesthetic changes inherent in partial mastectomy followed by radiation therapy in the treatment of stage I and stage II breast cancer. A retrospective analysis of breast cancer patients treated according to the National Surgical Adjuvant Breast Project Protocol B-06 was undertaken in 57 patients from 1984 to the present. The size of mastectomy varied between 2 x 1 cm and 15 x 8 cm. Objective aesthetic outcome, as determined by physical and photographic examination, was influenced primarily by surgical technique as opposed to the effects of radiation. These technical factors included orientation of resections, breast size relative to size of resection, location of tumor, and extent and orientation of axillary dissection. Regarding cosmesis, 80 percent of patients treated in this study judged their result to be excellent or good, in comparison to 50 percent excellent or good as judged by the plastic surgeon. Only 10 percent would consider mastectomy with reconstruction for contralateral disease. Asymmetry and contour abnormalities are far more common than noted in the radiation therapy literature. Patients satisfaction with lumpectomy and radiation, however, is very high. This satisfaction is not necessarily based on objective criteria defining aesthetic parameters, but is strongly influenced by retainment of the breast as an original body part.

  11. Brachytherapy with an improved MammoSite Radiation Therapy System

    NASA Astrophysics Data System (ADS)

    Karthik, Nanda; Keppel, Cynthia; Nazaryan, Vahagn

    2007-03-01

    Accelerated partial breast irradiation treatment utilizing the MammoSite Radiation Therapy System (MRTS) is becoming increasingly popular. Clinical studies show excellent results for disease control and localization, as well as for cosmesis. Several Phase I, II, and III clinical trials have found significant association between skin spacing and cosmetic results after treatment with MRTS. As a result, patients with skin spacing less then 7 mm are not recommended to undergo this treatment. We have developed a practical innovation to the MammoSite brachytherapy methodology that is directed to overcome the skin spacing problem. The idea is to partially shield the radiation dose to the skin where the skin spacing is less then 7 mm, thereby protecting the skin from radiation damage. Our innovation to the MRTS will allow better cosmetic outcome in breast conserving therapy (BCT), and will furthermore allow more women to take advantage of BCT. Reduction in skin radiation exposure is particularly important for patients also undergoing adjuvant chemotherapy. We will present the method and preliminary laboratory and Monte Carlo simulation results.

  12. Prone Breast Intensity Modulated Radiation Therapy: 5-Year Results

    SciTech Connect

    Osa, Etin-Osa O.; DeWyngaert, Keith; Roses, Daniel; Speyer, James; Guth, Amber; Axelrod, Deborah; Fenton Kerimian, Maria; Goldberg, Judith D.; Formenti, Silvia C.

    2014-07-15

    Purpose: To report the 5-year results of a technique of prone breast radiation therapy delivered by a regimen of accelerated intensity modulated radiation therapy with a concurrent boost to the tumor bed. Methods and Materials: Between 2003 and 2006, 404 patients with stage I-II breast cancer were prospectively enrolled into 2 consecutive protocols, institutional trials 03-30 and 05-181, that used the same regimen of 40.5 Gy/15 fractions delivered to the index breast over 3 weeks, with a concomitant daily boost to the tumor bed of 0.5 Gy (total dose 48 Gy). All patients were treated after segmental mastectomy and had negative margins and nodal assessment. Patients were set up prone: only if lung or heart volumes were in the field was a supine setup attempted and chosen if found to better spare these organs. Results: Ninety-two percent of patients were treated prone, 8% supine. Seventy-two percent had stage I, 28% stage II invasive breast cancer. In-field lung volume ranged from 0 to 228.27 cm{sup 3}, mean 19.65 cm{sup 3}. In-field heart volume for left breast cancer patients ranged from 0 to 21.24 cm{sup 3}, mean 1.59 cm{sup 3}. There was no heart in the field for right breast cancer patients. At a median follow-up of 5 years, the 5-year cumulative incidence of isolated ipsilateral breast tumor recurrence was 0.82% (95% confidence interval [CI] 0.65%-1.04%). The 5-year cumulative incidence of regional recurrence was 0.53% (95% CI 0.41%-0.69%), and the 5-year overall cumulative death rate was 1.28% (95% CI 0.48%-3.38%). Eighty-two percent (95% CI 77%-85%) of patients judged their final cosmetic result as excellent/good. Conclusions: Prone accelerated intensity modulated radiation therapy with a concomitant boost results in excellent local control and optimal sparing of heart and lung, with good cosmesis. Radiation Therapy Oncology Group protocol 1005, a phase 3, multi-institutional, randomized trial is ongoing and is evaluating the equivalence of a similar dose and fractionation approach to standard 6-week radiation therapy with a sequential boost.

  13. Definitive radiation therapy for squamous cell carcinoma of the vagina

    SciTech Connect

    Frank, Steven J.; Jhingran, Anuja; Levenback, Charles; Eifel, Patricia J. . E-mail: peifel@mdanderson.org

    2005-05-01

    Purpose: To evaluate outcome and describe clinical treatment guidelines for patients with primary squamous cell carcinoma of the vagina treated with definitive radiation therapy. Methods and Materials: Between 1970 and 2000, a total of 193 patients were treated with definitive radiation therapy for squamous cell carcinoma of the vagina at The University of Texas M. D. Anderson Cancer Center. The patients' medical records were reviewed to obtain information about patient, tumor, and treatment characteristics, as well as outcome and patterns of recurrence. Surviving patients were followed for a median of 137 months. Survival rates were calculated using the Kaplan-Meier method, with differences assessed using log-rank tests. Results: Disease-specific survival (DSS) and pelvic disease control rates correlated with International Federation of Gynecology and Obstetrics (FIGO) stage and tumor size. At 5 years, DSS rates were 85% for the 50 patients with Stage I, 78% for the 97 patients with Stage II, and 58% for the 46 patients with Stage III-IVA disease (p = 0.0013). Five-year DSS rates were 82% and 60% for patients with tumors {<=}4 cm or >4 cm, respectively (p = 0.0001). At 5 years, pelvic disease control rates were 86% for Stage I, 84% for Stage II, and 71% for Stage III-IVA (p = 0.027). The predominant mode of relapse after definitive radiation therapy was local-regional (68% and 83%, respectively, for patients with stages I-II or III-IVA disease). The incidence of major complications was correlated with FIGO stage; at 5 years, the rates of major complications were 4% for Stage I, 9% for Stage II, and 21% for Stage III-IVA (p < 0.01). Conclusions: Excellent outcomes can be achieved with definitive radiation therapy for invasive squamous cell carcinoma of the vagina. However, to achieve these results, treatment must be individualized according to the site and size of the tumor at presentation and the response to initial external-beam radiation therapy. Brachytherapy plays an important role in the treatment of many vaginal cancers but should be carefully selected and applied to obtain optimal coverage of the target volume.

  14. Radiation pneumonitis in breast cancer patients treated with conservative surgery and radiation therapy

    SciTech Connect

    Lingos, T.I.; Recht, A.; Vicini, F.; Abner, A.; Silver, B.; Harris, J.R. )

    1991-07-01

    The likelihood of radiation pneumonitis and factors associated with its development in breast cancer patients treated with conservative surgery and radiation therapy have not been well established. To assess these, the authors retrospectively reviewed 1624 patients treated between 1968 and 1985. Median follow-up for patients without local or distant failure was 77 months. Patients were treated with either tangential fields alone (n = 508) or tangents with a third field to the supraclavicular (SC) or SC-axillary (AX) region (n = 1116). Lung volume treated in the tangential fields was generally limited by keeping the perpendicular distance (demagnified) at the isocenter from the deep field edges to the posterior chest wall (CLD) to 3 cm or less. Seventeen patients with radiation pneumonitis were identified (1.0%). Radiation pneumonitis was diagnosed when patients presented with cough (15/17, 88%), fever (9/17, 53%), and/or dyspnea (6/17, 35%) and radiographic changes (17/17) following completion of RT. Radiographic infiltrates corresponded to treatment portals in all patients, and in 12 of the 17 patients, returned to baseline within 1-12 months. Five patients had permanent scarring on chest X ray. No patient had late or persistent pulmonary symptoms. The incidence of radiation pneumonitis was correlated with the combined use of chemotherapy (CT) and a third field. Three percent (11/328) of patients treated with a 3-field technique who received chemotherapy developed radiation pneumonitis compared to 0.5% (6 of 1296) for all other patients (p = 0.0001). When patients treated with a 3-field technique received chemotherapy concurrently with radiation therapy, the incidence of radiation pneumonitis was 8.8% (8/92) compared with 1.3% (3/236) for those who received sequential chemotherapy and radiation therapy (p = 0.002).

  15. Adjuvant and Salvage Radiation Therapy After Prostatectomy: American Society for Radiation Oncology/American Urological Association Guidelines

    SciTech Connect

    Valicenti, Richard K.; Thompson, Ian; Albertsen, Peter; Davis, Brian J.; Goldenberg, S. Larry; Wolf, J. Stuart; Sartor, Oliver; Klein, Eric; Hahn, Carol; Michalski, Jeff; Roach, Mack; Faraday, Martha M.

    2013-08-01

    Purpose: The purpose of this guideline was to provide a clinical framework for the use of radiation therapy after radical prostatectomy as adjuvant or salvage therapy. Methods and Materials: A systematic literature review using PubMed, Embase, and Cochrane database was conducted to identify peer-reviewed publications relevant to the use of radiation therapy after prostatectomy. The review yielded 294 articles; these publications were used to create the evidence-based guideline statements. Additional guidance is provided as Clinical Principles when insufficient evidence existed. Results: Guideline statements are provided for patient counseling, use of radiation therapy in the adjuvant and salvage contexts, defining biochemical recurrence, and conducting a restaging evaluation. Conclusions: Physicians should offer adjuvant radiation therapy to patients with adverse pathologic findings at prostatectomy (ie, seminal vesicle invastion, positive surgical margins, extraprostatic extension) and salvage radiation therapy to patients with prostate-specific antigen (PSA) or local recurrence after prostatectomy in whom there is no evidence of distant metastatic disease. The offer of radiation therapy should be made in the context of a thoughtful discussion of possible short- and long-term side effects of radiation therapy as well as the potential benefits of preventing recurrence. The decision to administer radiation therapy should be made by the patient and the multidisciplinary treatment team with full consideration of the patient's history, values, preferences, quality of life, and functional status. The American Society for Radiation Oncology and American Urological Association websites show this guideline in its entirety, including the full literature review.

  16. Medical factors influencing decision making regarding radiation therapy for breast cancer

    PubMed Central

    Dilaveri, Christina A; Sandhu, Nicole P; Neal, Lonzetta; Neben-Wittich, Michelle A; Hieken, Tina J; Mac Bride, Maire Brid; Wahner-Roedler, Dietlind L; Ghosh, Karthik

    2014-01-01

    Radiation therapy is an important and effective adjuvant therapy for breast cancer. Numerous health conditions may affect medical decisions regarding tolerance of breast radiation therapy. These factors must be considered during the decision-making process after breast-conserving surgery or mastectomy for breast cancer. Here, we review currently available evidence focusing on medical conditions that may affect the patient–provider decision-making process regarding the use of radiation therapy. PMID:25429241

  17. Androgen Deprivation Therapy Toxicity and Management for Men Receiving Radiation Therapy

    PubMed Central

    Johnson, Matthew E.; Buyyounouski, Mark K.

    2012-01-01

    Androgen deprivation therapy is commonly used in combination with radiotherapy as part of the definitive treatment for men with clinically localized and locally advanced prostate cancer. Androgen deprivation has been associated with a wide range of iatrogenic effects impacting a variety of body systems including metabolic, musculoskeletal, cardiovascular, neurocognitive, and sexual. This review aims to provide the radiation oncology community with the knowledge to monitor and manage androgen deprivation therapy toxicity in an effort to provide the highest level of care for patients and to minimize the iatrogenic effects of androgen deprivation as much as possible. PMID:23326671

  18. Imaging Changes in Pediatric Intracranial Ependymoma Patients Treated With Proton Beam Radiation Therapy Compared to Intensity Modulated Radiation Therapy

    SciTech Connect

    Gunther, Jillian R.; Sato, Mariko; Chintagumpala, Murali; Ketonen, Leena; Jones, Jeremy Y.; Allen, Pamela K.; Paulino, Arnold C.; Okcu, M. Fatih; Su, Jack M.; Weinberg, Jeffrey; Boehling, Nicholas S.; Khatua, Soumen; Adesina, Adekunle; Dauser, Robert; Whitehead, William E.; Mahajan, Anita

    2015-09-01

    Purpose: The clinical significance of magnetic resonance imaging (MRI) changes after radiation therapy (RT) in children with ependymoma is not well defined. We compared imaging changes following proton beam radiation therapy (PBRT) to those after photon-based intensity modulated RT (IMRT). Methods and Materials: Seventy-two patients with nonmetastatic intracranial ependymoma who received postoperative RT (37 PBRT, 35 IMRT) were analyzed retrospectively. MRI images were reviewed by 2 neuroradiologists. Results: Sixteen PBRT patients (43%) developed postradiation MRI changes at 3.8 months (median) with resolution by 6.1 months. Six IMRT patients (17%) developed changes at 5.3 months (median) with 8.3 months to resolution. Mean age at radiation was 4.4 and 6.9 years for PBRT and IMRT, respectively (P=.06). Age at diagnosis (>3 years) and time of radiation (≥3 years) was associated with fewer imaging changes on univariate analysis (odds ratio [OR]: 0.35, P=.048; OR: 0.36, P=.05). PBRT (compared to IMRT) was associated with more frequent imaging changes, both on univariate (OR: 3.68, P=.019) and multivariate (OR: 3.89, P=.024) analyses. Seven (3 IMRT, 4 PBRT) of 22 patients with changes had symptoms requiring intervention. Most patients were treated with steroids; some PBRT patients also received bevacizumab and hyperbaric oxygen therapy. None of the IMRT patients had lasting deficits, but 2 patients died from recurrent disease. Three PBRT patients had persistent neurological deficits, and 1 child died secondarily to complications from radiation necrosis. Conclusions: Postradiation MRI changes are more common with PBRT and in patients less than 3 years of age at diagnosis and treatment. It is difficult to predict causes for development of imaging changes that progress to clinical significance. These changes are usually self-limiting, but some require medical intervention, especially those involving the brainstem.

  19. Anonymization of DICOM electronic medical records for radiation therapy.

    PubMed

    Newhauser, Wayne; Jones, Timothy; Swerdloff, Stuart; Newhauser, Warren; Cilia, Mark; Carver, Robert; Halloran, Andy; Zhang, Rui

    2014-10-01

    Electronic medical records (EMR) and treatment plans are used in research on patient outcomes and radiation effects. In many situations researchers must remove protected health information (PHI) from EMRs. The literature contains several studies describing the anonymization of generic Digital Imaging and Communication in Medicine (DICOM) files and DICOM image sets but no publications were found that discuss the anonymization of DICOM radiation therapy plans, a key component of an EMR in a cancer clinic. In addition to this we were unable to find a commercial software tool that met the minimum requirements for anonymization and preservation of data integrity for radiation therapy research. The purpose of this study was to develop a prototype software code to meet the requirements for the anonymization of radiation therapy treatment plans and to develop a way to validate that code and demonstrate that it properly anonymized treatment plans and preserved data integrity. We extended an open-source code to process all relevant PHI and to allow for the automatic anonymization of multiple EMRs. The prototype code successfully anonymized multiple treatment plans in less than 1min/patient. We also tested commercial optical character recognition (OCR) algorithms for the detection of burned-in text on the images, but they were unable to reliably recognize text. In addition, we developed and tested an image filtering algorithm that allowed us to isolate and redact alpha-numeric text from a test radiograph. Validation tests verified that PHI was anonymized and data integrity, such as the relationship between DICOM unique identifiers (UID) was preserved. PMID:25147130

  20. Effects of radiation therapy and chemotherapy on testicular function

    SciTech Connect

    Kinsella, T.J. )

    1989-01-01

    Chemotherapy and radiation therapy are commonly used alone or in combination in the curative management of many malignancies in adolescent and adult males. Over the last 15-20 years, the striking success in the treatment of some common cancers in reproductive males has led to increasing concern for damage to normal tissues, such as the testes, resulting from curative cancer treatment. Indeed, a major future goal for cancer treatment will be to improve on the complication-free cure rate. Inherent in achieving this goal is to understand the pathophysiology and clinical expression of testicular injury. Both chemotherapy and radiation therapy result in germ cell depletion with the development of oligo- to azoospermia and testicular atrophy. The type of drug (particularly the alkylating agents), duration of treatment, intensity of treatment, and drug combination are major variables in determining the extent and duration of testicular injury. Testicular injury with chemotherapy also appears to vary with the age of the patient at the time of treatment. Newer drug combinations are now being used which appear to have curative potential in tumors such as Hodgkin's disease and germ cell testicular cancer with less potential for testicular injury. The most accurate and complete information on radiation injury to the testes is derived from two studies of normal volunteers who received graded single doses directly to the testes. A clear dose-response relationship of clinical and histological testicular damage was found with gradual recovery occurring following doses of up to 600 cGy. While these two studies provide an important clinical data base, radiation therapy used in treating cancers involves multiple daily treatments, usually 25-35 delivered over several weeks. Additionally, direct testicular irradiation is seldom used clinically. 37 references.

  1. Melanoma Therapy via Peptide-Targeted a-Radiation

    SciTech Connect

    Miao, Yubin; Hylarides, Mark; Fisher, Darrell R.; Shelton, Tiffani; Moore, Herbert A.; Wester, Dennis W.; Fritzberg, Alan R.; Winkelmann, Christopher T.; Hoffman, Timothy J.; Quinn, Thomas P.

    2005-08-01

    Malignant melanoma is the most lethal form of skin cancer. Current chemotherapy and external beam radiation therapy regimens are ineffective agents against melanoma, as shown by a 10-year survival rate for patients with disseminated disease of approximately 5% (reference?). In this study, the unique combination of a melanoma targeting peptide and an in vivo generated a-particle emitting radioisotope was investigated for its melanoma therapy potential. Alpha-radiation is densely ionizing and energy is locally absorbed, resulting in high concentrations of destructive free radicals and irreparable DNA double strand breaks. This high linear-energy-transfer overcomes radiation resistant tumor cells and oxygen-enhancement effects. The melanoma targeting peptide DOTA-Re(Arg11)CCMSH was radiolabeled with 212Pb, the parent of 212Bi, which decays via alpha and beta decay. Biodistribution and therapy studies were performed in the B16/F1 melanoma bearing C57 mouse flank tumor model. 212Pb[DOTA]-R e(Arg11)CCMSH exhibited rapid tumor uptake and extended retention coupled with rapid whole body disappearance. Radiation dose delivered to the tumor was estimated to be 61 cGy/uCi 212Pb administered. Treatment of melanoma-bearing mice with 50, 100 and 200 uCi of 212Pb[DOTA]-Re(Arg11)CCMSH extended mean survival of mice to 22, 28, and 49.8 days, respectively, compared to the 14.6 day mean survival of the placebo control group. Forty-five percent of the mice receiving 200 uCi survived the study disease-free.

  2. Influential Factors and Synergies for Radiation-Gene Therapy on Cancer

    PubMed Central

    Lin, Mei; Huang, Junxing; Shi, Yujuan; Xiao, Yanhong; Guo, Ting

    2015-01-01

    Radiation-gene therapy, a dual anticancer strategy of radiation therapy and gene therapy through connecting radiation-inducible regulatory sequence to therapeutic gene, leading to the gene being induced to express by radiation while radiotherapy is performed and finally resulting in a double synergistic antitumor effect of radiation and gene, has become one of hotspots in the field of cancer treatment in recent years. But under routine dose of radiation, especially in the hypoxia environment of solid tumor, it is difficult for this therapy to achieve desired effect because of low activity of radiation-inducible regulatory elements, low level and transient expression of target gene induced by radiation, inferior target specificity and poor biosecurity, and so on. Based on the problems existing in radiation-gene therapy, many efforts have been devoted to the curative effect improvement of radiation-gene therapy by various means to increase radiation sensitivity or enhance target gene expression and the expression's controllability. Among these synergistic techniques, gene circuit, hypoxic sensitization, and optimization of radiation-induced sequence exhibit a good application potential. This review provides the main influential factors to radiation-gene therapy on cancer and the synergistic techniques to improve the anticancer effect of radiation-gene therapy. PMID:26783511

  3. Spanish Society of Radiation Oncology clinical guidelines for stereotactic body radiation therapy in lymph node oligometastases.

    PubMed

    Conde-Moreno, A J; Lopez-Guerra, J L; Macias, V A; Vázquez de la Torre, M L; Samper Ots, P; San José-Maderuelo, S; Pastor Peidro, J; López-Torrecilla, J; Expósito-Hernández, J

    2016-04-01

    Data in the literature support the existence of a state of limited metastases or oligometastases. Favorable outcomes have been observed in selected patients with such oligometastases that are treated with local ablative therapies, which include surgical extirpation, stereotactic body radiation therapy (SBRT), and radiofrequency ablation. The role of SBRT in the setting of lymph node oligometastases is still emerging but the early results for local control are promising. However, the biggest challenge is to identify patients who will benefit from treatment of their oligometastatic disease with local aggressive therapy. Patients are initially categorized based upon examination of the initial biopsy, location, stage, and previous treatments received. Appropriate patient management with SBRT requires an understanding of several clinicopathological features that help to identify several subsets of patients with more responsive tumors and a good tolerance to SBRT. In an effort to incorporate the most recent evidence, here the Spanish Society of Radiation Oncology presents guidelines for using SBRT in lymph node oligometastases. PMID:26329294

  4. Hypofractionated Whole-Breast Radiation Therapy: Does Breast Size Matter?

    SciTech Connect

    Hannan, Raquibul; Thompson, Reid F.; Chen Yu; Bernstein, Karen; Kabarriti, Rafi; Skinner, William; Chen, Chin C.; Landau, Evan; Miller, Ekeni; Spierer, Marnee; Hong, Linda; Kalnicki, Shalom

    2012-11-15

    Purpose: To evaluate the effects of breast size on dose-volume histogram parameters and clinical toxicity in whole-breast hypofractionated radiation therapy using intensity modulated radiation therapy (IMRT). Materials and Methods: In this retrospective study, all patients undergoing breast-conserving therapy between 2005 and 2009 were screened, and qualifying consecutive patients were included in 1 of 2 cohorts: large-breasted patients (chest wall separation >25 cm or planning target volume [PTV] >1500 cm{sub 3}) (n=97) and small-breasted patients (chest wall separation <25 cm and PTV <1500 cm{sub 3}) (n=32). All patients were treated prone or supine with hypofractionated IMRT to the whole breast (42.4 Gy in 16 fractions) followed by a boost dose (9.6 Gy in 4 fractions). Dosimetric and clinical toxicity data were collected and analyzed using the R statistical package (version 2.12). Results: The mean PTV V95 (percentage of volume receiving >= 95% of prescribed dose) was 90.18% and the mean V105 percentage of volume receiving >= 105% of prescribed dose was 3.55% with no dose greater than 107%. PTV dose was independent of breast size, whereas heart dose and maximum point dose to skin correlated with increasing breast size. Lung dose was markedly decreased in prone compared with supine treatments. Radiation Therapy Oncology Group grade 0, 1, and 2 skin toxicities were noted acutely in 6%, 69%, and 25% of patients, respectively, and at later follow-up (>3 months) in 43%, 57%, and 0% of patients, respectively. Large breast size contributed to increased acute grade 2 toxicity (28% vs 12%, P=.008). Conclusions: Adequate PTV coverage with acceptable hot spots and excellent sparing of organs at risk was achieved by use of IMRT regardless of treatment position and breast size. Although increasing breast size leads to increased heart dose and maximum skin dose, heart dose remained within our institutional constraints and the incidence of overall skin toxicity was comparable to that reported in the literature. Taken together, these data suggest that hypofractionated radiation therapy using IMRT is a viable and appropriate therapeutic modality in large-breasted patients.

  5. Overview of Radiation Therapy for Treating Rectal Cancer

    PubMed Central

    Kye, Bong-Hyeon

    2014-01-01

    A major outcome of importance for rectal cancer is local control. Parallel to improvements in surgical technique, adjuvant therapy regimens have been tested in clinical trials in an effort to reduce the local recurrence rate. Nowadays, the local recurrence rate has been reduced because of both good surgical techniques and the addition of radiotherapy. Based on recent reports in the literature, preoperative chemoradiotherapy is now considered the standard of care for patients with stages II and III rectal cancer. Also, short-course radiotherapy appears to provide effective local control and the same overall survival as more long-course chemoradiotherapy schedules and, therefore, may be an appropriate choice in some situations. Capecitabine is an acceptable alternative to infusion fluorouracil in those patients who are able to manage the responsibilities inherent in self-administered, oral chemotherapy. However, concurrent administration of oxaliplatin and radiotherapy is not recommended at this time. Radiation therapy has long been considered an important adjunct in the treatment of rectal cancer. Although no prospective data exist for several issues, we hope that in the near future, patients with rectal cancer can be treated by using the best combination of surgery, radiation therapy, and chemotherapy in near future. PMID:25210685

  6. Breast Cancer After Chest Radiation Therapy for Childhood Cancer

    PubMed Central

    Moskowitz, Chaya S.; Chou, Joanne F.; Wolden, Suzanne L.; Bernstein, Jonine L.; Malhotra, Jyoti; Friedman, Danielle Novetsky; Mubdi, Nidha Z.; Leisenring, Wendy M.; Stovall, Marilyn; Hammond, Sue; Smith, Susan A.; Henderson, Tara O.; Boice, John D.; Hudson, Melissa M.; Diller, Lisa R.; Bhatia, Smita; Kenney, Lisa B.; Neglia, Joseph P.; Begg, Colin B.; Robison, Leslie L.; Oeffinger, Kevin C.

    2014-01-01

    Purpose The risk of breast cancer is high in women treated for a childhood cancer with chest irradiation. We sought to examine variations in risk resulting from irradiation field and radiation dose. Patients and Methods We evaluated cumulative breast cancer risk in 1,230 female childhood cancer survivors treated with chest irradiation who were participants in the CCSS (Childhood Cancer Survivor Study). Results Childhood cancer survivors treated with lower delivered doses of radiation (median, 14 Gy; range, 2 to 20 Gy) to a large volume (whole-lung field) had a high risk of breast cancer (standardized incidence ratio [SIR], 43.6; 95% CI, 27.2 to 70.3), as did survivors treated with high doses of delivered radiation (median, 40 Gy) to the mantle field (SIR, 24.2; 95% CI, 20.7 to 28.3). The cumulative incidence of breast cancer by age 50 years was 30% (95% CI, 25 to 34), with a 35% incidence among Hodgkin lymphoma survivors (95% CI, 29 to 40). Breast cancer–specific mortality at 5 and 10 years was 12% (95% CI, 8 to 18) and 19% (95% CI, 13 to 25), respectively. Conclusion Among women treated for childhood cancer with chest radiation therapy, those treated with whole-lung irradiation have a greater risk of breast cancer than previously recognized, demonstrating the importance of radiation volume. Importantly, mortality associated with breast cancer after childhood cancer is substantial. PMID:24752044

  7. Late effects of radiation therapy on the gastrointestinal tract

    SciTech Connect

    Coia, L.R.; Myerson, R.J.; Tepper, J.E.

    1995-03-30

    Late gastrointestinal complications of radiation therapy have been recognized but not extensively studied. In this paper, the late effects of radiation on three gastrointestinal sites, the esophagus, the stomach, and the bowel, are described. Esophageal dysmotility and benign stricture following esophageal irradiation are predominantly a result of damage to the esophageal wall, although mucosal ulcerations also may persist following high-dose radiation. The major late morbidity following gastric irradiation is gastric ulceration caused by mucosal destruction. Late radiation injury to the bowel, which may result in bleeding, frequency, fistula formation, and, particularly in small bowel, obstruction, is caused by damage to the entire thickness of the bowel wall, and predisposing factors have been identified. For each site a description of the pathogenesis, clinical findings, and present management is offered. Simple and reproducible endpoint scales for late toxicity measurement were developed and are presented for each of the three gastrointestinal organs. Factors important in analyzing late complications and future considerations in evaluation and management of radiation-related gastrointestinal injury are discussed.

  8. Accuracy of Marketing Claims by Providers of Stereotactic Radiation Therapy

    PubMed Central

    Narang, Amol K.; Lam, Edwin; Makary, Martin A.; DeWeese, Theodore L.; Pawlik, Timothy M.; Pronovost, Peter J.; Herman, Joseph M.

    2013-01-01

    Purpose: Direct-to-consumer advertising by industry has been criticized for encouraging overuse of unproven therapies, but advertising by health care providers has not been as carefully scrutinized. Stereotactic radiation therapy is an emerging technology that has sparked controversy regarding the marketing campaigns of some manufacturers. Given that this technology is also being heavily advertised on the Web sites of health care providers, the accuracy of providers' marketing claims should be rigorously evaluated. Methods: We reviewed the Web sites of all US hospitals and private practices that provide stereotactic radiation using two leading brands of stereotactic radiosurgery technology. Centers were identified by using data from the manufacturers. Centers without Web sites were excluded. The final study population consisted of 212 centers with online advertisements for stereotactic radiation. Web sites were evaluated for advertisements that were inconsistent with advertising guidelines provided by the American Medical Association. Results: Most centers (76%) had individual pages dedicated to the marketing of their brand of stereotactic technology that frequently contained manufacturer-authored images (50%) or text (55%). Advertising for the treatment of tumors that have not been endorsed by professional societies was present on 66% of Web sites. Centers commonly claimed improved survival (22%), disease control (20%), quality of life (17%), and toxicity (43%) with stereotactic radiation. Although 40% of Web sites championed the center's regional expertise in delivering stereotactic treatments, only 15% of Web sites provided data to support their claims. Conclusion: Provider advertisements for stereotactic radiation were prominent and aggressive. Further investigation of provider advertising, its effects on quality of care, and potential oversight mechanisms is needed. PMID:23633973

  9. The Arginine/ADMA Ratio Is Related to the Prevention of Atherosclerotic Plaques in Hypercholesterolemic Rabbits When Giving a Combined Therapy with Atorvastatine and Arginine

    PubMed Central

    Brinkmann, Saskia J. H.; Wörner, Elisabeth A.; Buijs, Nikki; Richir, Milan; Cynober, Luc; van Leeuwen, Paul A. M.; Couderc, Rémy

    2015-01-01

    Supplementation with arginine in combination with atorvastatin is more efficient in reducing the size of an atherosclerotic plaque than treatment with a statin or arginine alone in homozygous Watanabe heritable hyperlipidemic (WHHL) rabbits. We evaluated the mechanism behind this feature by exploring the role of the arginine/asymmetric dimethylarginine (ADMA) ratio, which is the substrate and inhibitor of nitric oxide synthase (NOS) and thereby nitric oxide (NO), respectively. Methods: Rabbits were fed either an arginine diet (group A, n = 9), standard rabbit chow plus atorvastatin (group S, n = 8), standard rabbit chow plus an arginine diet with atorvastatin (group SA, n = 8) or standard rabbit chow (group C, n = 9) as control. Blood was sampled and the aorta was harvested for topographic and histological analysis. Plasma levels of arginine, ADMA, cholesterol and nitric oxide were determined and the arginine/ADMA ratio was calculated. Results: The decrease in ADMA levels over time was significantly correlated to fewer aortic lesions in the distal aorta and total aorta. The arginine/ADMA ratio was correlated to cholesterol levels and decrease in cholesterol levels over time in the SA group. A lower arginine/ADMA ratio was significantly correlated to lower NO levels in the S and C group. Discussion: A balance between arginine and ADMA is an important indicator in the prevention of the development of atherosclerotic plaques. PMID:26035753

  10. MR Imaging of Coronary Arteries and Plaques.

    PubMed

    Dweck, Marc R; Puntman, Valentina; Vesey, Alex T; Fayad, Zahi A; Nagel, Eike

    2016-03-01

    Cardiac magnetic resonance offers the promise of radiation-free imaging of the coronary arteries, providing information with respect to luminal stenosis, plaque burden, high-risk plaque characteristics, and disease activity. In combination, this would provide a comprehensive, individualized assessment of coronary atherosclerosis that could be used to improve patient risk stratification and to guide treatment. However, the technical challenges involved with delivering upon this promise are considerable, requiring sophisticated approaches to both data acquisition and post-processing. In this review, we describe the current status of this technology, its capabilities, its limitations, and what will be required in the future to translate this technology into routine clinical practice. PMID:26965732

  11. Regorafenib-induced transverse myelopathy after stereotactic body radiation therapy.

    PubMed

    Tian, Sibo; Nissenblatt, Michael; Goyal, Sharad

    2014-12-01

    Stereotactic body radiation therapy (SBRT) delivers large doses of radiation with great accuracy, but is known to have deleterious effects on the vascular compartment of irradiated tissues. Combining SBRT with targeted anti-angiogenesis agents, while able to increase therapeutic efficacy, may unexpectedly precipitate vascular-based toxicities. In this report, we describe a patient with colon cancer who developed transverse myelopathy from regorafenib 2 years after receiving SBRT for three metastatic liver lesions. Regorafenib (Stivarga), formerly BAY 73-4506, (Bayer HealthCare Pharmaceuticals, Montville, NJ) is a multiple receptor tyrosine kinase inhibitor with anti-angiogenic effects used in metastatic colon cancer. Its most common side effects are fatigue, diarrhea and hypertension. However, severe neurologic toxicity has not been previously recognized. Here, we illustrate a case in which the patient developed hyperalgesia and radicular pain 2 weeks after starting regorafenib. Several studies report an increased neurological toxicity when angiogenesis inhibitors are given after radiation therapy, and we postulate that the angioinhibitory effects of regorafenib accelerated subclinical microvascular injury from SBRT. This unexpected toxicity may be clinically relevant when giving targeted angiogenesis inhibitors after SBRT. PMID:25436137

  12. Regorafenib-induced transverse myelopathy after stereotactic body radiation therapy

    PubMed Central

    Tian, Sibo; Nissenblatt, Michael

    2014-01-01

    Stereotactic body radiation therapy (SBRT) delivers large doses of radiation with great accuracy, but is known to have deleterious effects on the vascular compartment of irradiated tissues. Combining SBRT with targeted anti-angiogenesis agents, while able to increase therapeutic efficacy, may unexpectedly precipitate vascular-based toxicities. In this report, we describe a patient with colon cancer who developed transverse myelopathy from regorafenib 2 years after receiving SBRT for three metastatic liver lesions. Regorafenib (Stivarga), formerly BAY 73-4506, (Bayer HealthCare Pharmaceuticals, Montville, NJ) is a multiple receptor tyrosine kinase inhibitor with anti-angiogenic effects used in metastatic colon cancer. Its most common side effects are fatigue, diarrhea and hypertension. However, severe neurologic toxicity has not been previously recognized. Here, we illustrate a case in which the patient developed hyperalgesia and radicular pain 2 weeks after starting regorafenib. Several studies report an increased neurological toxicity when angiogenesis inhibitors are given after radiation therapy, and we postulate that the angioinhibitory effects of regorafenib accelerated subclinical microvascular injury from SBRT. This unexpected toxicity may be clinically relevant when giving targeted angiogenesis inhibitors after SBRT. PMID:25436137

  13. Stereotactic body radiation therapy for prostate cancer: Rational and reasonable.

    PubMed

    Kupelian, Patrick; Mehta, Niraj H; King, Chris; Steinberg, Michael; Finkelstein, Steven E; Fernandez, Eduardo

    2015-01-01

    Stereotactic body radiation therapy (SBRT), a treatment procedure that uses large doses per fraction, is currently being used to treat prostate cancer with external radiation therapy in 4 to 5 treatments. Published series in the clinical use of SBRT in patients with localized prostate cancer demonstrate high efficacy within the available follow-up time periods. Rectal and sexual toxicity profiles have been favorable compared with other radiation techniques and surgery. Urinary toxicity profiles might be more comparable to those observed with brachytherapy, more pronounced in the acute setting. SBRT is technically more challenging, requiring precise geometric targeting with in-room image guidance. The use of large doses per fraction potentially provides unique biological effects on both tumor and normal tissues. Immunologic responses in normal tissues, local stromal microenvironment, and specific antigen-presenting cells induced by such high doses likely contribute to effective tumor kill. Ultimately, SBRT for prostate cancer offers significant logistical advantages, with increased convenience to patients and decreased overall cost to the health care delivery system. PMID:25413392

  14. Third generation gold nanoplatform optimized for radiation therapy

    PubMed Central

    Kumar, Rajiv; Korideck, Houari; Ngwa, Wilfred; Berbeco, Ross I.; Makrigiorgos, G. Mike; Sridhar, Srinivas

    2013-01-01

    We report the design and fabrication of third generation ultrasmall PEGylated gold nanoparticles based platform (AuRad™) optimized for applications in radiation therapy. The AuRad™ nanoplatform has the following key features: (I) surface coating of hetero-bifunctional-PEG with amine, carboxyl, methoxy functional groups, which make this a versatile nanoplatform to conjugate various moieties like fluorophores, peptides, drugs, radiolabels; (II) size that is optimized for longer circulation, higher tumor uptake and modulated clearance; (III) high radiation enhancement. We have synthesized ultrasmall 2–3 nm gold nanoparticles, followed by attachment of hetero-bifunctional PEG and further conjugation of fluorophore AlexaFlour 647 for optical imaging, with a stability of more than 6 months. Confocal bioimaging with HeLa cells showed robust uptake of biocompatible nanoparticles in cells. Irradiation experiments X-rays showed greater than 2.8-fold cell kill enhancement as demonstrated by clonogenic survival assays. The results indicate that AuRad nanoplatform can act as potential theranostic agent in radiation therapy. PMID:24392307

  15. Strategies for quality assurance of intensity modulated radiation therapy

    NASA Astrophysics Data System (ADS)

    Benedek, Hunor; Isacsson, Ulf; Olevik-Dunder, Maria; Westermark, Mathias; Hållström, Per; Olofsson, Jörgen; Gustafsson, Magnus

    2015-01-01

    In late 2011 The Swedish Society of Radiation Physics formed a working group to concentrate on the Quality Assurance of modern radiation therapy techniques. The given task was to identify and summarise the different QA strategies in Sweden and also the international recommendations. This was used to formulate recommendations for practical guidelines within Sweden. In this paper a brief summery of the group's work is presented. All the Swedish radiation therapy centres do a pre treatment verification measurement as QA for every new IMRT and VMAT plan. Physicists do it and they believe it to be time consuming. A general standpoint from all the centres was that new guidelines and legislation is needed to allow QA that does not require a measurement. Based on various international publications and recommendations the working group has presented two strategies, one where all new plans are checked through measurement and one where no measurement is needed. The measurement- based strategy is basically the same as the one used today with an extended machine QA part. The other presented strategy is process oriented where all the different parts of the treatment chain are checked separately. The final report can be found in Swedish on http://www.radiofysik.org.

  16. Implementation of Remote 3-Dimensional Image Guided Radiation Therapy Quality Assurance for Radiation Therapy Oncology Group Clinical Trials

    SciTech Connect

    Cui Yunfeng; Galvin, James M.; Radiation Therapy Oncology Group, American College of Radiology, Philadelphia, Pennsylvania ; Parker, William; Breen, Stephen; Yin Fangfang; Cai Jing; Papiez, Lech S.; Li, X. Allen; Bednarz, Greg; Chen Wenzhou; Xiao Ying

    2013-01-01

    Purpose: To report the process and initial experience of remote credentialing of three-dimensional (3D) image guided radiation therapy (IGRT) as part of the quality assurance (QA) of submitted data for Radiation Therapy Oncology Group (RTOG) clinical trials; and to identify major issues resulting from this process and analyze the review results on patient positioning shifts. Methods and Materials: Image guided radiation therapy datasets including in-room positioning CT scans and daily shifts applied were submitted through the Image Guided Therapy QA Center from institutions for the IGRT credentialing process, as required by various RTOG trials. A centralized virtual environment is established at the RTOG Core Laboratory, containing analysis tools and database infrastructure for remote review by the Physics Principal Investigators of each protocol. The appropriateness of IGRT technique and volumetric image registration accuracy were evaluated. Registration accuracy was verified by repeat registration with a third-party registration software system. With the accumulated review results, registration differences between those obtained by the Physics Principal Investigators and from the institutions were analyzed for different imaging sites, shift directions, and imaging modalities. Results: The remote review process was successfully carried out for 87 3D cases (out of 137 total cases, including 2-dimensional and 3D) during 2010. Frequent errors in submitted IGRT data and challenges in the review of image registration for some special cases were identified. Workarounds for these issues were developed. The average differences of registration results between reviewers and institutions ranged between 2 mm and 3 mm. Large discrepancies in the superior-inferior direction were found for megavoltage CT cases, owing to low spatial resolution in this direction for most megavoltage CT cases. Conclusion: This first experience indicated that remote review for 3D IGRT as part of QA for RTOG clinical trials is feasible and effective. The magnitude of registration discrepancy between institution and reviewer was presented, and the major issues were investigated to further improve this remote evaluation process.

  17. Surgery and radiation therapy for extramedullary plasmacytoma of the penile mucosa in a dog

    PubMed Central

    Wypij, Jackie M.; de Lorimier, Louis-Philippe

    2012-01-01

    A 10-year-old neutered male Italian greyhound dog was presented because it had a penile plasmacytoma. Surgery followed by radiation therapy resulted in local control and survival for 1688 days. This is the first report of surgery and definitive radiation therapy for curative intent therapy of extramedullary penile plasmacytoma in a dog. PMID:23450865

  18. On coupled Boltzmann transport equation related to radiation therapy

    NASA Astrophysics Data System (ADS)

    Tervo, J.

    2007-11-01

    We consider a system of Boltzmann transport equations which models the charged particle evolution in media. The system is related to the dose calculation in radiation therapy. Although only one species of particles, say photons is invasing these particles mobilize other type of particles (electrons and positrons). Hence in realistic modelling of particle transport one needs a coupled system of three Boltzmann transport equations. The solution of this system must satisfy the inflow boundary condition. We show existence and uniqueness result of the solution applying generalized Lax-Milgram Theorem. In addition, we verify that (in the case of external therapy) under certain assumptions the "incoming flux to dose operator" D1 is compact. Also the adjoint is analyzed. Finally we consider the inverse planning problem as an optimal control problem. Its solution can be used as an initial solution of the actual inverse planning problem.

  19. A Method for Evaluating Quality Assurance Needs in Radiation Therapy

    SciTech Connect

    Huq, M. Saiful Fraass, Benedick A.; Dunscombe, Peter B.; Gibbons, John P.; Ibbott, Geoffrey S.; Medin, Paul M.; Mundt, Arno; Mutic, Sassa; Palta, Jatinder R.; Thomadsen, Bruce R.; Williamson, Jeffrey F.; Yorke, Ellen D.

    2008-05-01

    The increasing complexity of modern radiation therapy planning and delivery techniques challenges traditional prescriptive quality control and quality assurance programs that ensure safety and reliability of treatment planning and delivery systems under all clinical scenarios. Until now quality management (QM) guidelines published by concerned organizations (e.g., American Association of Physicists in Medicine [AAPM], European Society for Therapeutic Radiology and Oncology [ESTRO], International Atomic Energy Agency [IAEA]) have focused on monitoring functional performance of radiotherapy equipment by measurable parameters, with tolerances set at strict but achievable values. In the modern environment, however, the number and sophistication of possible tests and measurements have increased dramatically. There is a need to prioritize QM activities in a way that will strike a balance between being reasonably achievable and optimally beneficial to patients. A systematic understanding of possible errors over the course of a radiation therapy treatment and the potential clinical impact of each is needed to direct limited resources in such a way to produce maximal benefit to the quality of patient care. Task Group 100 of the AAPM has taken a broad view of these issues and is developing a framework for designing QM activities, and hence allocating resources, based on estimates of clinical outcome, risk assessment, and failure modes. The report will provide guidelines on risk assessment approaches with emphasis on failure mode and effect analysis (FMEA) and an achievable QM program based on risk analysis. Examples of FMEA to intensity-modulated radiation therapy and high-dose-rate brachytherapy are presented. Recommendations on how to apply this new approach to individual clinics and further research and development will also be discussed.

  20. A method for evaluating quality assurance needs in radiation therapy.

    PubMed

    Huq, M Saiful; Fraass, Benedick A; Dunscombe, Peter B; Gibbons, John P; Ibbott, Geoffrey S; Medin, Paul M; Mundt, Arno; Mutic, Sassa; Palta, Jatinder R; Thomadsen, Bruce R; Williamson, Jeffrey F; Yorke, Ellen D

    2008-01-01

    The increasing complexity of modern radiation therapy planning and delivery techniques challenges traditional prescriptive quality control and quality assurance programs that ensure safety and reliability of treatment planning and delivery systems under all clinical scenarios. Until now quality management (QM) guidelines published by concerned organizations (e.g., American Association of Physicists in Medicine [AAPM], European Society for Therapeutic Radiology and Oncology [ESTRO], International Atomic Energy Agency [IAEA]) have focused on monitoring functional performance of radiotherapy equipment by measurable parameters, with tolerances set at strict but achievable values. In the modern environment, however, the number and sophistication of possible tests and measurements have increased dramatically. There is a need to prioritize QM activities in a way that will strike a balance between being reasonably achievable and optimally beneficial to patients. A systematic understanding of possible errors over the course of a radiation therapy treatment and the potential clinical impact of each is needed to direct limited resources in such a way to produce maximal benefit to the quality of patient care. Task Group 100 of the AAPM has taken a broad view of these issues and is developing a framework for designing QM activities, and hence allocating resources, based on estimates of clinical outcome, risk assessment, and failure modes. The report will provide guidelines on risk assessment approaches with emphasis on failure mode and effect analysis (FMEA) and an achievable QM program based on risk analysis. Examples of FMEA to intensity-modulated radiation therapy and high-dose-rate brachytherapy are presented. Recommendations on how to apply this new approach to individual clinics and further research and development will also be discussed. PMID:18406920

  1. Change in Seroma Volume During Whole-Breast Radiation Therapy

    SciTech Connect

    Sharma, Rajiv; Spierer, Marnee Mutyala, Subhakar; Thawani, Nitika; Cohen, Hillel W.; Hong, Linda; Garg, Madhur K.; Kalnicki, Shalom

    2009-09-01

    Purpose: After breast-conserving surgery, a seroma often forms in the surgical cavity. If not drained, it may affect the volume of tumor bed requiring a boost after whole-breast radiation therapy (WBRT). Our objective was to evaluate the change in seroma volume that occurs during WBRT, before boost planning. Methods and Materials: A retrospective review was performed of women receiving breast-conserving therapy with evidence of seroma at the time of WBRT planning. Computed tomography (CT) simulation was performed before WBRT and before the tumor bed boost. All patients received either a hypofractionated (42.4 Gy/16 fraction + 9.6 Gy/4 fraction boost) or standard fractionated (50.4 Gy/28 fraction + 10 Gy/5 fraction boost) regimen. Seroma volumes were contoured and compared on CT at the time of WBRT simulation and tumor bed boost planning. Results: Twenty-four patients with evidence of seroma were identified and all patients received WBRT without drainage of the seroma. Mean seroma volume before WBRT and at boost planning were significantly different at 65.7 cm{sup 3} (SD, 50.5 cm{sup 3}) and 35.6 cm{sup 3} (SD, 24.8 cm{sup 3}), respectively (p < 0.001). Mean and median reduction in seroma volume during radiation were 39.6% (SD, 23.8%) and 46.2% (range, 10.7-76.7%), respectively. Fractionation schedule was not correlated with change in seroma volume. Length of time from surgery to start of radiation therapy showed an inverse correlation with change in seroma volume (Pearson correlation r = -0.53, p < 0.01). Conclusions: The volume of seroma changes significantly during WBRT. Consequently, the accuracy of breast boost planning is likely affected, as is the volume of normal breast tissue irradiated. CT-based boost planning before boost irradiation is suggested to ensure appropriate coverage.

  2. Lineal energy and radiation quality in radiation therapy: model calculations and comparison with experiment

    NASA Astrophysics Data System (ADS)

    Lindborg, L.; Hultqvist, M.; Carlsson Tedgren, Å.; Nikjoo, H.

    2013-05-01

    Microdosimetry is a recommended method for characterizing radiation quality in situations when the biological effectiveness under test is not well known. In such situations, the radiation beams are described by their lineal energy probability distributions. Results from radiobiological investigations in the beams are then used to establish response functions that relate the lineal energy to the relative biological effectiveness (RBE). In this paper we present the influence of the size of the simulated volume on the relation to the clinical RBE values (or weighting factors). A single event probability distribution of the lineal energy is approximated by its dose average lineal energy (\\bar y_D) which can be measured or calculated for volumes from a few micrometres down to a few nanometres. The clinical RBE values were approximated as the ratio of the α-values derived from the LQ-relation. Model calculations are presented and discussed for the SOBP of a 12C ion (290 MeV u-1) and the reference 60Co γ therapy beam. Results were compared with those for a conventional x-ray therapy beam, a 290 MeV proton beam and a neutron therapy beam. It is concluded that for a simulated volume of about 10 nm, the α-ratio increases approximately linearly with the \\bar y_D-ratio for all the investigated beams. The correlation between y and α provides the evidence to characterize a radiation therapy beam by the lineal energy when, for instance, weighting factors are to be estimated.

  3. Linear algebraic methods applied to intensity modulated radiation therapy.

    PubMed

    Crooks, S M; Xing, L

    2001-10-01

    Methods of linear algebra are applied to the choice of beam weights for intensity modulated radiation therapy (IMRT). It is shown that the physical interpretation of the beam weights, target homogeneity and ratios of deposited energy can be given in terms of matrix equations and quadratic forms. The methodology of fitting using linear algebra as applied to IMRT is examined. Results are compared with IMRT plans that had been prepared using a commercially available IMRT treatment planning system and previously delivered to cancer patients. PMID:11686277

  4. 3D Monte Carlo radiation transfer modelling of photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Campbell, C. Louise; Christison, Craig; Brown, C. Tom A.; Wood, Kenneth; Valentine, Ronan M.; Moseley, Harry

    2015-06-01

    The effects of ageing and skin type on Photodynamic Therapy (PDT) for different treatment methods have been theoretically investigated. A multilayered Monte Carlo Radiation Transfer model is presented where both daylight activated PDT and conventional PDT are compared. It was found that light penetrates deeper through older skin with a lighter complexion, which translates into a deeper effective treatment depth. The effect of ageing was found to be larger for darker skin types. The investigation further strengthens the usage of daylight as a potential light source for PDT where effective treatment depths of about 2 mm can be achieved.

  5. TH-A-BRD-01: Radiation Biology for Radiation Therapy Physicists

    SciTech Connect

    Orton, C; Borras, C; Carlson, D

    2014-06-15

    Mechanisms by which radiation kills cells and ways cell damage can be repaired will be reviewed. The radiobiological parameters of dose, fractionation, delivery time, dose rate, and LET will be discussed. The linear-quadratic model for cell survival for high and low dose rate treatments and the effect of repopulation will be presented and discussed. The rationale for various radiotherapy techniques such as conventional fractionation, hyperfractionation, hypofractionation, and low and high dose rate brachytherapy, including permanent implants, will be presented. The radiobiological principles underlying radiation protection guidelines and the different radiation dosimetry terms used in radiation biology and in radiation protection will be reviewed. Human data on radiation induced cancer, including increases in the risk of second cancers following radiation therapy, as well as data on radiation induced tissue reactions, such as cardiovascular effects, for follow up times up to 20–40 years, published by ICRP, NCRP and BEIR Committees, will be examined. The latest risk estimates per unit dose will be presented. Their adoption in recent radiation protection standards and guidelines and their impact on patient and workers safety in radiotherapy will be discussed. Biologically-guided radiotherapy (BGRT) provides a systematic method to derive prescription doses that integrate patient-specific information about tumor and normal tissue biology. Treatment individualization based on patient-specific biology requires the identification of biological objective functions to facilitate the design and comparison of competing treatment modalities. Biological objectives provide a more direct approach to plan optimization instead of relying solely on dose-based surrogates and can incorporate factors that alter radiation response, such as DNA repair, tumor hypoxia, and relative biological effectiveness. We review concepts motivating biological objectives and provide examples of how they might be used to address clinically relevant problems. Underlying assumptions and limitations of existing models and their proper application will be discussed. This multidisciplinary educational session combines the fundamentals of radiobiology for radiation therapy and radiation protection with the practical application of biophysical models for treatment planning and evaluation. Learning Objectives: To understand fractionation in teletherapy and dose rate techniques in brachytherapy. To understand how the linear-quadratic models the effect of radiobiological parameters for radiotherapy. To understand the radiobiological basis of radiation protection standards applied to radiotherapy. To distinguish between stochastic effects and tissue reactions. To learn how to apply concepts of biological effective dose and RBE-weighted dose and to incorporate biological factors that alter radiation response. To discuss clinical strategies to increase therapeutic ratio, i.e., maximize local control while minimizing the risk of acute and late normal tissue effects.

  6. Whole-brain radiation therapy for brain metastases: detrimental or beneficial?

    PubMed

    Gemici, Cengiz; Yaprak, Gokhan

    2015-01-01

    Stereotactic radiosurgery is frequently used, either alone or together with whole-brain radiation therapy to treat brain metastases from solid tumors. Certain experts and radiation oncology groups have proposed replacing whole-brain radiation therapy with stereotactic radiosurgery alone for the management of brain metastases. Although randomized trials have favored adding whole-brain radiation therapy to stereotactic radiosurgery for most end points, a recent meta-analysis demonstrated a survival disadvantage for patients treated with whole-brain radiation therapy and stereotactic radiosurgery compared with patients treated with stereotactic radiosurgery alone. However the apparent detrimental effect of adding whole-brain radiation therapy to stereotactic radiosurgery reported in this meta-analysis may be the result of inhomogeneous distribution of the patients with respect to tumor histologies, molecular histologic subtypes, and extracranial tumor stages between the groups rather than a real effect. Unfortunately, soon after this meta-analysis was published, even as an abstract, use of whole-brain radiation therapy in managing brain metastases has become controversial among radiation oncologists. The American Society of Radiation Oncology recently recommended, in their "Choose Wisely" campaign, against routinely adding whole-brain radiation therapy to stereotactic radiosurgery to treat brain metastases. However, this situation creates conflict for radiation oncologists who believe that there are enough high level of evidence for the effectiveness of whole-brain radiation therapy in the treatment of brain metastases. PMID:26215106

  7. The Vulnerable Plaque: the Real Villain in Acute Coronary Syndromes

    PubMed Central

    Liang, Michael; Puri, Aniket; Devlin, Gerard

    2011-01-01

    The term "vulnerable plaque" refers to a vascular lesion that is prone to rupture and may result in life-threatening events which include myocardial infarction. It consists of thin-cap fibroatheroma and a large lipid core which is highly thrombogenic. Acute coronary syndromes often result from rupture of vulnerable plaques which frequently are only moderately stenosed and not visible by conventional angiography. Several invasive and non-invasive strategies have been developed to assess the burden of vulnerable plaques. Intravascular ultrasound provides a two-dimensional cross-sectional image of the arterial wall and can help assess the plaque burden and composition. Optical coherent tomography offers superior resolution over intravascular ultrasound. High-resolution magnetic resonance imaging provides non-invasive imaging for visualizing fibrous cap thickness and rupture in plaques. In addition, it may be of value in assessing the effects of treatments, such as lipid-lowering therapy. Technical issues however limit its clinical applicability. The role of multi-slice computed tomography, a well established screening tool for coronary artery disease, remains to be determined. Fractional flow reserve (FFR) may provide physiological functional assessment of plaque vulnerability; however, its role in the management of vulnerable plaque requires further studies. Treatment of the vulnerable patient may involve systemic therapy which currently include statins, ACE inhibitors, beta-blockers, aspirin, and calcium-channel blockers and in the future local therapeutic options such as drug-eluting stents or photodynamic therapy. PMID:21673834

  8. Technical aspects of radiation therapy for anal cancer

    PubMed Central

    Scher, Eli D.; Ahmed, Inaya; Yue, Ning J.

    2014-01-01

    Historically treated with surgery, current practice recommends anal carcinoma to be treated with a combination of chemotherapy and radiation. This review will examine the anatomy, modes of disease spread and recurrence, and evaluate the existing evidence for treatment options for these tumors. An in-depth examination of specific radiation therapy (RT) techniques—such as conventional 3D-conformal RT and intensity-modulated RT—will be discussed along with modern dose constraints. RT field arrangement, patient setup, and recommended gross and clinical target volume (CTV) contours will be considered. Areas in need of further investigation, such as the role in treatment for positron emission tomography (PET) will be explored. PMID:24982768

  9. Cherenkov imaging and biochemical sensing in vivo during radiation therapy

    NASA Astrophysics Data System (ADS)

    Zhang, Rongxiao

    While Cherenkov emission was discovered more than eighty years ago, the potential applications of imaging this during radiation therapy have just recently been explored. With approximately half of all cancer patients being treated by radiation at some point during their cancer management, there is a constant challenge to ensure optimal treatment efficiency is achieved with maximal tumor to normal tissue therapeutic ratio. To achieve this, the treatment process as well as biological information affecting the treatment should ideally be effective and directly derived from the delivery of radiation to the patient. The value of Cherenkov emission imaging was examined here, primarily for visualization of treatment monitoring and then secondarily for Cherenkov-excited luminescence for tissue biochemical sensing within tissue. Through synchronized gating to the short radiation pulses of a linear accelerator (200Hz & 3 micros pulses), and applying a gated intensified camera for imaging, the Cherenkov radiation can be captured near video frame rates (30 frame per sec) with dim ambient room lighting. This procedure, sometimes termed Cherenkoscopy, is readily visualized without affecting the normal process of external beam radiation therapy. With simulation, phantoms and clinical trial data, each application of Cherenkoscopy was examined: i) for treatment monitoring, ii) for patient position monitoring and motion tracking, and iii) for superficial dose imaging. The temporal dynamics of delivered radiation fields can easily be directly imaged on the patient's surface. Image registration and edge detection of Cherenkov images were used to verify patient positioning during treatment. Inter-fraction setup accuracy and intra-fraction patient motion was detectable to better than 1 mm accuracy. Cherenkov emission in tissue opens up a new field of biochemical sensing within the tissue environment, using luminescent agents which can be activated by this light. In the first study of its kind with external beam irradiation, a dendritic platinum-based phosphor (PtG4) was used at micro-molar concentrations (~5 microM) to generate Cherenkov-induced luminescent signals, which are sensitive to the partial pressure of oxygen. Both tomographic reconstruction methods and linear scanned imaging were investigated here to examine the limits of detection. Recovery of optical molecular distributions was shown in tissue phantoms and small animals, with high accuracy (~1 microM), high spatial resolution (~0.2 mm) and deep-tissue detectability (~2 cm for Cherenkov luminescence scanned imaging (CELSI)), indicating potentials for in vivo and clinical use. In summary, many of the physical and technological details of Cherenkov imaging and Cherenkov-excited emission imaging were specified in this study.

  10. Preoperative Intensity Modulated Radiation Therapy for Retroperitoneal Sarcoma

    PubMed Central

    El-Bared, Nancy; Taussky, Daniel; Mehiri, Selma; Patocskai, Erika; Roberge, David; Donath, David

    2014-01-01

    The use of intensity modulated radiation therapy (IMRT) has allowed for the administration of high doses to retroperitoneal sarcomas (RSTS) while limiting toxicity to adjacent organs. The purpose of our study is to assess the outcome and toxicities of patients with RSTS treated with neo-adjuvant external beam radiation (EBRT) therapy using IMRT. This is a retrospective study of 21 patients treated with preoperative IMRT for primary or recurrent RSTS between 2005 and 2011. Overall survival (OS) and local recurrence free survival (LRFS) were computed using the Kaplan-Meier method (log-rank test). Acute and chronic toxicities were assessed using the CTCAE v. 3 criteria. The actuarial 2 and 3-year OS was 66% for both and the 5-year OS was 51%. As for LRFS it was 57% at 2 and 3-year and 51% for the 5-year LRFS. Factors predictive for local control were microscopically negative margins (p = 0.022), a median tumor diameter <5 cm (p = 0.007) and pathology of liposarcoma (p = 0.021). Furthermore, patients treated for recurrent disease fared worse (p = 0.04) in local control than patients treated for primary disease. As for OS, patients treated for Grade 1 histology had a better outcome (p = 0.05). EBRT was generally well tolerated. Acute gastrointestinal (GI) Grade 1 or 2 toxicities occurred in 33% of patients and one patient had unexplained post-radiation Grade 2 fever that resolved after tumor resection. As for chronic toxicities 24% of our patients presented Grade 1 GI toxicity and one patient presented Grade 3 small bowel stenosis not clearly due to radiation toxicity. Despite the location and volume of the tumors treated, preoperative IMRT was very well tolerated in our patients with retroperitoneal sarcoma. Unfortunately local recurrences remain common and dose escalation is to be considered. PMID:23919397

  11. Preoperative intensity modulated radiation therapy for retroperitoneal sarcoma.

    PubMed

    El-Bared, Nancy; Taussky, Daniel; Mehiri, Selma; Patocskai, Erika; Roberge, David; Donath, David

    2014-06-01

    The use of intensity modulated radiation therapy (IMRT) has allowed for the administration of high doses to retroperitoneal sarcomas (RSTS) while limiting toxicity to adjacent organs. The purpose of our study is to assess the outcome and toxicities of patients with RSTS treated with neo-adjuvant external beam radiation (EBRT) therapy using IMRT. This is a retrospective study of 21 patients treated with preoperative IMRT for primary or recurrent RSTS between 2005 and 2011. Overall survival (OS) and local recurrence free survival (LRFS) were computed using the Kaplan-Meier method (log-rank test). Acute and chronic toxicities were assessed using the CTCAE v. 3 criteria. The actuarial 2 and 3-year OS was 66% for both and the 5-year OS was 51%. As for LRFS it was 57% at 2 and 3-year and 51% for the 5-year LRFS. Factors predictive for local control were microscopically negative margins (p = 0.022), a median tumor diameter <15 cm (p = 0.007) and pathology of liposarcoma (p = 0.021). Furthermore, patients treated for recurrent disease fared worse (p = 0.04) in local control than patients treated for primary disease. As for OS, patients treated for Grade 1 histology had a better outcome (p 5 0.05). EBRT was generally well tolerated. Acute gastrointestinal (GI) Grade 1 or 2 toxicities occurred in 33% of patients and one patient had unexplained post-radiation Grade 2 fever that resolved after tumor resection. As for chronic toxicities 24% of our patients presented Grade 1 GI toxicity and one patient presented Grade 3 small bowel stenosis not clearly due to radiation toxicity. Despite the location and volume of the tumors treated, preoperative IMRT was very well tolerated in our patients with retroperitoneal sarcoma. Unfortunately local recurrences remain common and dose escalation is to be considered. PMID:23919397

  12. Fast Monte Carlo for radiation therapy: the PEREGRINE Project

    SciTech Connect

    Hartmann Siantar, C.L.; Bergstrom, P.M.; Chandler, W.P.; Cox, L.J.; Daly, T.P.; Garrett, D.; House, R.K.; Moses, E.I.; Powell, C.L.; Patterson, R.W.; Schach von Wittenau, A.E.

    1997-11-11

    The purpose of the PEREGRINE program is to bring high-speed, high- accuracy, high-resolution Monte Carlo dose calculations to the desktop in the radiation therapy clinic. PEREGRINE is a three- dimensional Monte Carlo dose calculation system designed specifically for radiation therapy planning. It provides dose distributions from external beams of photons, electrons, neutrons, and protons as well as from brachytherapy sources. Each external radiation source particle passes through collimator jaws and beam modifiers such as blocks, compensators, and wedges that are used to customize the treatment to maximize the dose to the tumor. Absorbed dose is tallied in the patient or phantom as Monte Carlo simulation particles are followed through a Cartesian transport mesh that has been manually specified or determined from a CT scan of the patient. This paper describes PEREGRINE capabilities, results of benchmark comparisons, calculation times and performance, and the significance of Monte Carlo calculations for photon teletherapy. PEREGRINE results show excellent agreement with a comprehensive set of measurements for a wide variety of clinical photon beam geometries, on both homogeneous and heterogeneous test samples or phantoms. PEREGRINE is capable of calculating >350 million histories per hour for a standard clinical treatment plan. This results in a dose distribution with voxel standard deviations of <2% of the maximum dose on 4 million voxels with 1 mm resolution in the CT-slice plane in under 20 minutes. Calculation times include tracking particles through all patient specific beam delivery components as well as the patient. Most importantly, comparison of Monte Carlo dose calculations with currently-used algorithms reveal significantly different dose distributions for a wide variety of treatment sites, due to the complex 3-D effects of missing tissue, tissue heterogeneities, and accurate modeling of the radiation source.

  13. Delineation of Supraclavicular Target Volumes in Breast Cancer Radiation Therapy

    SciTech Connect

    Brown, Lindsay C.; Diehn, Felix E.; Boughey, Judy C.; Childs, Stephanie K.; Park, Sean S.; Yan, Elizabeth S.; Petersen, Ivy A.; Mutter, Robert W.

    2015-07-01

    Purpose: To map the location of gross supraclavicular metastases in patients with breast cancer, in order to determine areas at highest risk of harboring subclinical disease. Methods and Materials: Patients with axial imaging of gross supraclavicular disease were identified from an institutional breast cancer registry. Locations of the metastatic lymph nodes were transferred onto representative axial computed tomography images of the supraclavicular region and compared with the Radiation Therapy Oncology Group (RTOG) breast cancer atlas for radiation therapy planning. Results: Sixty-two patients with 161 supraclavicular nodal metastases were eligible for study inclusion. At the time of diagnosis, 117 nodal metastases were present in 44 patients. Forty-four nodal metastases in 18 patients were detected at disease recurrence, 4 of whom had received prior radiation to the supraclavicular fossa. Of the 161 nodal metastases, 95 (59%) were within the RTOG consensus volume, 4 nodal metastases (2%) in 3 patients were marginally within the volume, and 62 nodal metastases (39%) in 30 patients were outside the volume. Supraclavicular disease outside the RTOG consensus volume was located in 3 regions: at the level of the cricoid and thyroid cartilage (superior to the RTOG volume), in the posterolateral supraclavicular fossa (posterolateral to the RTOG volume), and in the lateral low supraclavicular fossa (lateral to the RTOG volume). Only women with multiple supraclavicular metastases had nodal disease that extended superiorly to the level of the thyroid cartilage. Conclusions: For women with risk of harboring subclinical supraclavicular disease warranting the addition of supraclavicular radiation, coverage of the posterior triangle and the lateral low supraclavicular region should be considered. For women with known supraclavicular disease, extension of neck coverage superior to the cricoid cartilage may be warranted.

  14. Monte Carlo dose enhancement studies in microbeam radiation therapy

    SciTech Connect

    Martinez-Rovira, I.; Prezado, Y.

    2011-07-15

    Purpose: A radical radiation therapy treatment for gliomas requires extremely high absorbed doses resulting in subsequent deleterious side effects in healthy tissue. Microbeam radiation therapy (MRT) is an innovative technique based on the fact that normal tissue can withstand high radiation doses in small volumes without any significant damage. The synchrotron-generated x-ray beam is collimated and delivered to an array of narrow micrometer-sized planar rectangular fields. Several preclinical experiments performed at the Brookhaven National Laboratory (BNL) and at the European Synchrotron Radiation Facility (ESRF) confirmed that MRT yields a higher therapeutic index than nonsegmented beams of the same characteristics. This index can be greatly improved by loading the tumor with high atomic number (Z) contrast agents. The aim of this work is to find the high-Z element that provides optimum dose enhancement. Methods: Monte Carlo simulations (PENELOPE/penEasy) were performed to assess the peak and valley doses as well as their ratio (PVDR) in healthy tissue and in the tumor, loaded with different contrast agents. The optimization criteria used were maximization of the ratio between the PVDR values in healthy tissue respect to the PVDR in the tumor and minimization of bone and brain valley doses. Results: Dose enhancement factors, PVDR, and valley doses were calculated for different high-Z elements. A significant decrease of PVDR values in the tumor, accompanied by a gain in the valley doses, was found in the presence of high-Z elements. This enables the deposited dose in the healthy tissue to be reduced. The optimum high-Z element depends on the irradiation configuration. As a general trend, the best outcome is provided by the highest Z contrast agents considered, i.e., gold and thallium. However, lanthanides (especially Lu) and hafnium also offer a satisfactory performance. Conclusions: The remarkable therapeutic index in microbeam radiation therapy can be further improved by loading the tumor with a high-Z element. This study reports quantitative data on several dosimetric magnitudes in order to find the optimum contrast agent. Although the final choice of the element will also depend on possible cytotoxicity, three elements were found to be worthy of mention: gold, thallium, and lutetium.

  15. Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy.

    PubMed

    Kunos, Charles A; Fabien, Jeffrey M; Shanahan, John P; Collen, Christine; Gevaert, Thierry; Poels, Kenneth; Van den Begin, Robbe; Engels, Benedikt; De Ridder, Mark

    2015-01-01

    Physicians considering stereotactic ablative body radiation therapy (SBRT) for the treatment of extracranial cancer targets must be aware of the sizeable risks for normal tissue injury and the hazards of physical tumor miss. A first-of-its-kind SBRT platform achieves high-precision ablative radiation treatment through a combination of versatile real-time imaging solutions and sophisticated tumor tracking capabilities. It uses dual-diagnostic kV x-ray units for stereoscopic open-loop feedback of cancer target intrafraction movement occurring as a consequence of respiratory motions and heartbeat. Image-guided feedback drives a gimbaled radiation accelerator (maximum 15 x 15 cm field size) capable of real-time ±4 cm pan-and-tilt action. Robot-driven ±60° pivots of an integrated ±185° rotational gantry allow for coplanar and non-coplanar accelerator beam set-up angles, ultimately permitting unique treatment degrees of freedom. State-of-the-art software aids real-time six dimensional positioning, ensuring irradiation of cancer targets with sub-millimeter accuracy (0.4 mm at isocenter). Use of these features enables treating physicians to steer radiation dose to cancer tumor targets while simultaneously reducing radiation dose to normal tissues. By adding respiration correlated computed tomography (CT) and 2-[(18)F] fluoro-2-deoxy-ᴅ-glucose ((18)F-FDG) positron emission tomography (PET) images into the planning system for enhanced tumor target contouring, the likelihood of physical tumor miss becomes substantially less. In this article, we describe new radiation plans for the treatment of moving lung tumors. PMID:26131774

  16. Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy

    PubMed Central

    Kunos, Charles A.; Fabien, Jeffrey M.; Shanahan, John P.; Collen, Christine; Gevaert, Thierry; Poels, Kenneth; Van den Begin, Robbe; Engels, Benedikt; De Ridder, Mark

    2015-01-01

    Physicians considering stereotactic ablative body radiation therapy (SBRT) for the treatment of extracranial cancer targets must be aware of the sizeable risks for normal tissue injury and the hazards of physical tumor miss. A first-of-its-kind SBRT platform achieves high-precision ablative radiation treatment through a combination of versatile real-time imaging solutions and sophisticated tumor tracking capabilities. It uses dual-diagnostic kV x-ray units for stereoscopic open-loop feedback of cancer target intrafraction movement occurring as a consequence of respiratory motions and heartbeat. Image-guided feedback drives a gimbaled radiation accelerator (maximum 15 x 15 cm field size) capable of real-time ±4 cm pan-and-tilt action. Robot-driven ±60° pivots of an integrated ±185° rotational gantry allow for coplanar and non-coplanar accelerator beam set-up angles, ultimately permitting unique treatment degrees of freedom. State-of-the-art software aids real-time six dimensional positioning, ensuring irradiation of cancer targets with sub-millimeter accuracy (0.4 mm at isocenter). Use of these features enables treating physicians to steer radiation dose to cancer tumor targets while simultaneously reducing radiation dose to normal tissues. By adding respiration correlated computed tomography (CT) and 2-[18F] fluoro-2-deoxy-ᴅ-glucose (18F-FDG) positron emission tomography (PET) images into the planning system for enhanced tumor target contouring, the likelihood of physical tumor miss becomes substantially less1. In this article, we describe new radiation plans for the treatment of moving lung tumors. PMID:26131774

  17. Potency preservation following stereotactic body radiation therapy for prostate cancer

    PubMed Central

    2013-01-01

    Background Erectile dysfunction after prostate radiation therapy remains an ongoing challenge and critical quality of life issue. Given the higher dose of radiation per fraction using stereotactic body radiation therapy (SBRT) there is concern that post-SBRT impotency would be higher than conventional radiation therapy approaches. This study sought to evaluate potency preservation and sexual function following SBRT for prostate cancer. Methods Between February 2008 and March 2011, 216 men with clinically localized prostate cancer were treated definitively with SBRT monotherapy at Georgetown University Hospital. Potency was defined as the ability to have an erection firm enough for intercourse with or without sexual aids while sexual activity was defined as the ability to have an erection firm enough for masturbation and foreplay. Patients who received androgen deprivation therapy (ADT) were excluded from this study. Ninety-seven hormone-naïve men were identified as being potent at the initiation of therapy and were included in this review. All patients were treated to 35–36.25 Gy in 5 fractions delivered with the CyberKnife Radiosurgical System (Accuray). Prostate specific antigen (PSA) and total testosterone levels were obtained pre-treatment, every 3 months for the first year and every 6 months for the subsequent year. Sexual function was assessed with the Sexual Health Inventory for Men (SHIM), the Expanded Prostate Index Composite (EPIC)-26 and Utilization of Sexual Medication/Device questionnaires at baseline and all follow-up visits. Results Ninety-seven men (43 low-, 50 intermediate- and 4 high-risk) at a median age of 68 years (range, 48–82 years) received SBRT. The median pre-treatment PSA was 5.9 ng/ml and the minimum follow-up was 24 months. The median pre-treatment total serum testosterone level was 11.4 nmol/L (range, 4.4-27.9 nmol/L). The median baseline SHIM was 22 and 36% of patients utilized sexual aids prior to treatment. Although potency rates declined following treatment: 100% (baseline); 68% (6 months); 62% (12 months); 57% (18 months) and 54.4% (24 months), 78% of previously potent patients had erections sufficient for sexual activity at 24 months post-treatment. Overall sexual aid utilization increased from 36% at baseline to 49% at 24 months. Average EPIC sexual scores showed a slow decline over the first two years following treatment: 77.6 (baseline); 68.7 (6 months); 63.2 (12 months); 61.9 (18 months); 59.3 (24 months). All sexual functions including orgasm declined with time. Prior to treatment, 13.4% of men felt their sexual function was a moderate to big problem which increased to 26.7% two years post treatment. Post-treatment testosterone levels gradually decreased with a median value at two year follow-up of 10.7 nmol/L. However, the average EPIC hormonal scores did not illustrate a statistically significant difference two years post-treatment. Review of the radiation doses to the penile bulb in this study, a potential marker of post-treatment sexual function, revealed that the dose was relatively low and at these low doses the percentage of the penile bulb receiving 29.5 Gy did not correlate with the development of ED. Conclusions Men undergoing SBRT monotherapy for prostate cancer report sexual outcomes comparable to those reported for conventional radiation modalities within the first 24 months after treatment. Longer follow-up is required to confirm the durability of these findings. PMID:24180317

  18. Molecular chemotherapy combined with radiation therapy enhances killing of cholangiocarcinoma cells in vitro and in vivo.

    PubMed

    Pederson, L C; Buchsbaum, D J; Vickers, S M; Kancharla, S R; Mayo, M S; Curiel, D T; Stackhouse, M A

    1997-10-01

    Cholangiocarcinoma is a virtually incurable tumor, resistant to current surgical, chemotherapy, and radiotherapy interventions. We applied the gene therapy strategy of toxin gene conversion of nontoxic prodrug to chemotherapeutic drug in combination with radiation therapy to the treatment of cholangiocarcinoma. In this regard, 5-fluorouracil (5-FU) is an accepted radiosensitizing and chemotherapeutic agent presently used in cancer therapy. The Escherichia coli enzyme cytosine deaminase (CD) converts the prodrug 5-fluorocytosine (5-FC) to 5-FU. Therefore, our goal was to express the CD gene in the human cholangiocarcinoma cell line, SK-ChA-1, assess the cytotoxicity of intracellular production of 5-FU, and determine any enhanced cell killing by the addition of external beam radiation. The susceptibility of SK-ChA-1 cells to recombinant adenoviral infection was determined by fluorescence-activated cell sorting analysis. We used the recombinant adenoviral vector AdCMVLacZ, encoding the E. coli beta-galactosidase reporter gene under control of the human cytomegalovirus (CMV) promoter, to infect SK-ChA-1 and HeLa cells at 10 and 100 plaque forming units (pfu)/cell, followed by FACS analysis. To evaluate CD-mediated conversion of 5-FC to 5-FU and subsequent cytotoxicity, SK-ChA-1 cells were infected with the recombinant adenovirus AdCMVCD, which encodes CD. Cells were then plated in 96-well microtiter plates and exposed to varying concentrations of 5-FC. Cell proliferation assays (tetrazolium salt conversion to formazan colorimetric assay) were performed beginning 2-8 days after plating. We evaluated the effects of external beam radiation using a single 8 Gy 60Co dose to AdCMVCD infected cells, with prior exposure to 5-FC for 2-3 days. MTS assays were performed following radiation treatment. Radiation dose-response analysis, via clonogenic assay, was used as a more sensitive assay to confirm the interaction of the treatment conditions. s.c. SK-ChA-1 tumors in athymic nude mice were established, which then received three intratumoral injections of 1 x 10(9) pfu AdCMVCD. Mice received i.p. injections of 400 mg/kg of 5-FC twice daily for 7 days beginning the day of initial AdCMVCD injection (day -2). The radiation treatment group received 10 Gy of 60Co exposure to their tumor on day 0. SK-ChA-1 cells were efficiently transduced (48.7 and 99.2%) by 10 and 100 pfu/cell of AdCMVLacZ, respectively. From 37.9 to 84.4% of SK-ChA-1 cells were killed following infection with 10 pfu/cell AdCMVCD and 8 days of exposure to various concentrations of 5-FC (5, 10, 30, 50, and 100 microg/ml). Higher 5-FC concentrations and longer duration of exposure resulted in greater cell killing. Radiation treatment (8 Gy) enhanced cell killing by greater than 70% when combined with 10 or 20 microg/ml of 5-FC. Radiation dose-response analysis with clonogenic assay confirmed enhanced SK-ChA-1 cell cytotoxicity as a result of radiation treatment following AdCMVCD infection and 5-FC exposure, with radiobiological parameters alpha = 0.44 and D0 = 0.96. Combined treatment of SK-ChA-1 tumors with AdCMVCD, 5-FC, and radiation in animals resulted in significantly greater survival, time to tumor regrowth, and doubling time compared to the nonradiation treatment group (P = 0.03, 0.015, and 0.002, respectively). Significantly greater change in tumor size, smaller ratio of final tumor size to original tumor size, and smaller final tumor size were observed in the radiation treatment group compared to the no radiation treatment group (P = 0.02, 0.03, and 0.03, respectively). Human cholangiocarcinoma cells were transduced with a recombinant adenovirus in vitro at high efficiency and were susceptible to CD-mediated intracellular 5-FU production. Radiobiological survival curve parameters confirmed an interactive cytotoxic effect when viral infection and prodrug therapy were combined with external beam radiation exposure. (ABSTRACT TRUNCATED) PMID:9331094

  19. Radiation hardness of the storage phosphor europium doped potassium chloride for radiation therapy dosimetry

    PubMed Central

    Driewer, Joseph P.; Chen, Haijian; Osvet, Andres; Low, Daniel A.; Li, H. Harold

    2011-01-01

    Purpose: An important property of a reusable dosimeter is its radiation hardness, that is, its ability to retain its dosimetric merits after irradiation. The radiation hardness of europium doped potassium chloride (KCl:Eu2+), a storage phosphor material recently proposed for radiation therapy dosimetry, is examined in this study. Methods: Pellet-style KCl:Eu2+ dosimeters, 6 mm in diameter, and 1 mm thick, were fabricated in-house for this study. The pellets were exposed by a 6 MV photon beam or in a high dose rate 137Cs irradiator. Macroscopic properties, such as radiation sensitivity, dose response linearity, and signal stability, were studied with a laboratory photostimulated luminescence (PSL) readout system. Since phosphor performance is related to the state of the storage centers and the activator, Eu2+, in the host lattice, spectroscopic and temporal measurements were carried out in order to explore radiation-induced changes at the microscopic level. Results: KCl:Eu2+ dosimeters retained approximately 90% of their initial signal strength after a 5000 Gy dose history. Dose response was initially supralinear over the dose range of 100–700 cGy but became linear after 60 Gy. Linearity did not change significantly in the 0–5000 Gy dose history spanned in this study. Annealing high dose history chips resulted in a return of supralinearity and a recovery of sensitivity. There were no significant changes in the PSL stimulation spectra, PSL emission spectra, photoluminescence spectra, or luminescence lifetime, indicating that the PSL signal process remains intact after irradiation but at a reduced efficiency due to reparable radiation-induced perturbations in the crystal lattice. Conclusions: Systematic studies of KCl:Eu2+ material are important for understanding how the material can be optimized for radiation therapy dosimetry purposes. The data presented here indicate that KCl:Eu2+ exhibits strong radiation hardness and lends support for further investigations of this novel material. PMID:21928642

  20. Radiation hardness of the storage phosphor europium doped potassium chloride for radiation therapy dosimetry

    SciTech Connect

    Driewer, Joseph P.; Chen, Haijian; Osvet, Andres; Low, Daniel A.; Li, H. Harold

    2011-08-15

    Purpose: An important property of a reusable dosimeter is its radiation hardness, that is, its ability to retain its dosimetric merits after irradiation. The radiation hardness of europium doped potassium chloride (KCl:Eu{sup 2+}), a storage phosphor material recently proposed for radiation therapy dosimetry, is examined in this study. Methods: Pellet-style KCl:Eu{sup 2+} dosimeters, 6 mm in diameter, and 1 mm thick, were fabricated in-house for this study. The pellets were exposed by a 6 MV photon beam or in a high dose rate {sup 137}Cs irradiator. Macroscopic properties, such as radiation sensitivity, dose response linearity, and signal stability, were studied with a laboratory photostimulated luminescence (PSL) readout system. Since phosphor performance is related to the state of the storage centers and the activator, Eu{sup 2+}, in the host lattice, spectroscopic and temporal measurements were carried out in order to explore radiation-induced changes at the microscopic level. Results: KCl:Eu{sup 2+} dosimeters retained approximately 90% of their initial signal strength after a 5000 Gy dose history. Dose response was initially supralinear over the dose range of 100-700 cGy but became linear after 60 Gy. Linearity did not change significantly in the 0-5000 Gy dose history spanned in this study. Annealing high dose history chips resulted in a return of supralinearity and a recovery of sensitivity. There were no significant changes in the PSL stimulation spectra, PSL emission spectra, photoluminescence spectra, or luminescence lifetime, indicating that the PSL signal process remains intact after irradiation but at a reduced efficiency due to reparable radiation-induced perturbations in the crystal lattice. Conclusions: Systematic studies of KCl:Eu{sup 2+} material are important for understanding how the material can be optimized for radiation therapy dosimetry purposes. The data presented here indicate that KCl:Eu{sup 2+} exhibits strong radiation hardness and lends support for further investigations of this novel material.

  1. Image-guided radiation therapy in lymphoma management

    PubMed Central

    Eng, Tony

    2015-01-01

    Image-guided radiation therapy (IGRT) is a process of incorporating imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), Positron emission tomography (PET), and ultrasound (US) during radiation therapy (RT) to improve treatment accuracy. It allows real-time or near real-time visualization of anatomical information to ensure that the target is in its position as planned. In addition, changes in tumor volume and location due to organ motion during treatment can be also compensated. IGRT has been gaining popularity and acceptance rapidly in RT over the past 10 years, and many published data have been reported on prostate, bladder, head and neck, and gastrointestinal cancers. However, the role of IGRT in lymphoma management is not well defined as there are only very limited published data currently available. The scope of this paper is to review the current use of IGRT in the management of lymphoma. The technical and clinical aspects of IGRT, lymphoma imaging studies, the current role of IGRT in lymphoma management and future directions will be discussed. PMID:26484299

  2. Radiation therapy plan checks in a paperless clinic.

    PubMed

    Siochi, R Alfredo; Pennington, Edward C; Waldron, Timothy J; Bayouth, John E

    2009-01-01

    Traditional quality assurance checks of a patient's radiation therapy plan involve printing out treatment parameters from the treatment planning system and the "record and verify" (R&V) system and visually checking the information for one-to-one correspondence. In a paperless environment, one can automate this process through independent software that can read the treatment planning data directly and compare it against the parameters in the R&V system's database. In addition to verifying the data integrity, it is necessary to check the logical consistency of the data and the accuracy of various calculations. The results are then imported into the patient's electronic medical record. Appropriate workflows must be developed to ensure that no steps of the QA process are missed. This paper describes our electronic QA system (EQS), consisting of in-house software and workflows. The EQS covers 3D conformal and intensity modulated radiation therapy, electrons, stereotactic radiosurgery, total body irradiation, and clinical set ups with and without virtual simulation. The planning systems handled by our EQS are ADAC Pinnacle and Varian FASTPLAN, while the R&V systems are LANTIS and VARIS. The improvement in our plan check process over the paperless system is described in terms of the types of detected errors. The potential problems with the implementation and use of the EQS, as well as workarounds for data that are not easily accessible through electronic means, are described. PMID:19223840

  3. Subacute brain atrophy after radiation therapy for malignant brain tumor

    SciTech Connect

    Asai, A.; Matsutani, M.; Kohno, T.; Nakamura, O.; Tanaka, H.; Fujimaki, T.; Funada, N.; Matsuda, T.; Nagata, K.; Takakura, K.

    1989-05-15

    Brain atrophy with mental and neurologic deterioration developing a few months after radiation therapy in patients without residual or recurrent brain tumors has been recognized. Two illustrative case reports of this pathologic entity are presented. Six autopsy cases with this entity including the two cases were reviewed neurologically, radiographically, and histopathologically. All patients presented progressive disturbances of mental status and consciousness, akinesia, and tremor-like involuntary movement. Computerized tomography (CT) demonstrated marked enlargement of the ventricles, moderate widening of the cortical sulci, and a moderately attenuated CT number for the white matter in all six patients. Four of the six patients had CSF drainage (ventriculoperitoneal shunt or continuous lumbar drainage), however, none of them improved. Histologic examination demonstrated swelling and loss of the myelin sheath in the white matter in all patients, and reactive astrocytosis in three of the six patients. Neither prominent neuronal loss in the cerebral cortex or basal ganglia, nor axonal loss in the white matter was generally identified. The blood vessels of the cerebral cortex and white matter were normal. Ependymal layer and the surrounding brain tissue were normal in all patients. These findings suggested that this pathologic condition results from demyelination secondary to direct neurotoxic effect of irradiation. The authors' previous report was reviewed and the differential diagnoses, the risk factors for this pathologic entity, and the indication for radiation therapy in aged patients with a malignant brain tumor are discussed.

  4. Outcome and Prognostic Factors of Radiation Therapy for Medulloblastoma

    SciTech Connect

    Rieken, Stefan; Mohr, Angela; Habermehl, Daniel; Welzel, Thomas; Lindel, Katja; Witt, Olaf; Kulozik, Andreas E.; Wick, Wolfgang; Debus, Juergen; Combs, Stephanie E.

    2011-11-01

    Purpose: To investigate treatment outcome and prognostic factors after radiation therapy in patients with medulloblastomas (MB). Methods and Materials: Sixty-six patients with histologically confirmed MB were treated at University Hospital of Heidelberg between 1985 and 2009. Forty-two patients (64%) were pediatric ({<=}18 years), and 24 patients (36%) were adults. Tumor resection was performed in all patients and was complete in 47%. All patients underwent postoperative craniospinal irradiation (CSI) delivering a median craniospinal dose of 35.5 Gy with additional boosts to the posterior fossa up to 54.0 Gy. Forty-seven patients received chemotherapy, including 21 in whom chemotherapy was administered before CSI. Statistical analysis was performed using the log-rank test and the Kaplan-Meier method. Results: Median follow-up was 93 months. Overall survival (OS) and local and distant progression-free survival (LPFS and DPFS) were 73%, 62%, and 77% at 60 months. Both local and distant recurrence predisposed for significantly reduced OS. Macroscopic complete tumor resection, desmoplastic histology and early initiation of postoperative radiation therapy within 28 days were associated with improved outcome. The addition of chemotherapy did not improve survival rates. Toxicity was moderate. Conclusions: Complete resection of MB followed by CSI yields long survival rates in both children and adults. Delayed initiation of CSI is associated with poor outcome. Desmoplastic histology is associated with improved survival. The role of chemotherapy, especially in the adult population, must be further investigated in clinical studies.

  5. Sexual function after surgical and radiation therapy for cervical carcinoma

    SciTech Connect

    Seibel, M.; Freeman, M.G.; Graves, W.L.

    1982-10-01

    One hundred women treated for carcinoma of the cervix were interviewed more than one year later to establish the effects of radiation or surgical therapy on sexual function. Forty-three had received irradiation, 44 nonradical surgery, six combined surgery and irradiation, and seven radical surgery. The irradiation and nonradical surgery groups were each further subdivided into subgroups of patients aged 30 to 49 for age-controlled comparison. Patients in the irradiation group had statistically significant decreases in sexual enjoyment, ability to attain orgasm, coital opportunity, frequency of intercourse, and coital desire. The group who had nonradical surgical procedures had no significant change in sexual function after treatment. Similar results were found in both age-controlled subgroups, eliminating age as a major etiologic factor. Marked vaginal alterations were recorded in the majority of irradiated patients, but were not present among the groups treated with nonradical surgery. The vaginal changes alone could not be held accountable for the significant decrease in sexual function among women who received pelvic irradiation. The origin of decreased sexual desire after radiation therapy is complex, and not yet completely understood. We propose therapeutic programs to help women deal with the emotional and physical consequences of pelvic irradiation.

  6. Hyperbaric Oxygen Therapy for Radiation-Induced Cystitis and Proctitis

    SciTech Connect

    Oliai, Caspian; Fisher, Brandon; Jani, Ashish; Wong, Michael; Poli, Jaganmohan; Brady, Luther W.; Komarnicky, Lydia T.

    2012-11-01

    Purpose: To provide a retrospective analysis of the efficacy of hyperbaric oxygen therapy (HBOT) for treating hemorrhagic cystitis (HC) and proctitis secondary to pelvic- and prostate-only radiotherapy. Methods and Materials: Nineteen patients were treated with HBOT for radiation-induced HC and proctitis. The median age at treatment was 66 years (range, 15-84 years). The range of external-beam radiation delivered was 50.0-75.6 Gy. Bleeding must have been refractory to other therapies. Patients received 100% oxygen at 2.0 atmospheres absolute pressure for 90-120 min per treatment in a monoplace chamber. Symptoms were retrospectively scored according to the Late Effects of Normal Tissues-Subjective, Objective, Management, Analytic (LENT-SOMA) scale to evaluate short-term efficacy. Recurrence of hematuria/hematochezia was used to assess long-term efficacy. Results: Four of the 19 patients were lost to follow-up. Fifteen patients were evaluated and received a mean of 29.8 dives: 11 developed HC and 4 proctitis. All patients experienced a reduction in their LENT-SOMA score. After completion of HBOT, the mean LENT-SOMA score was reduced from 0.78 to 0.20 in patients with HC and from 0.66 to 0.26 in patients with proctitis. Median follow-up was 39 months (range, 7-70 months). No cases of hematuria were refractory to HBOT. Complete resolution of hematuria was seen in 81% (n = 9) and partial response in 18% (n = 2). Recurrence of hematuria occurred in 36% (n = 4) after a median of 10 months. Complete resolution of hematochezia was seen in 50% (n = 2), partial response in 25% (n = 1), and refractory bleeding in 25% (n = 1). Conclusions: Hyperbaric oxygen therapy is appropriate for radiation-induced HC once less time-consuming therapies have failed to resolve the bleeding. In these conditions, HBOT is efficacious in the short and long term, with minimal side effects.

  7. Focused radiation hepatitis after Bragg-peak proton therapy for hepatocellular carcinoma: CT findings

    SciTech Connect

    Okumura, Toshiyuki; Itai, Yuji; Tsuji, Hiroshi

    1994-09-01

    Radiation hepatitis is clearly demonstrated by noncontrast and contrast enhanced CT following radiotherapy for liver diseases. Radiation hepatitis is dependent on dose distribution and is usually demonstrated as nonsegmental bandlike lesion after photon therapy. We report a case of focused, oval-shaped radiation hepatitis that was induced by photon therapy. The attenuation difference was localized in a high-dose area caused by Bragg-peak proton therapy. 17 refs., 2 figs.

  8. Monitoring the radiation dose to a multiprogrammable pacemaker during radical radiation therapy: A case report

    SciTech Connect

    Muller-Runkel, R.; Orsolini, G.; Kalokhe, U.P. )

    1990-11-01

    Multiprogrammable pacemakers, using complimentary metaloxide semiconductor (CMOS) circuitry, may fail during radiation therapy. We report about a patient who received 6,400 cGy for unresectable carcinoma of the left lung. In supine treatment position, arms raised above the head, the pacemaker was outside the treated area by a margin of at least 1 cm, shielded by cerrobend blocking mounted on a tray. From thermoluminescent dosimeter (TLD) measurements, we estimate that the pacemaker received 620 cGy in scatter doses. Its function was monitored before, during, and after completion of radiation therapy. The pacemaker was functioning normally until the patient's death 5 months after completion of treatment. The relevant electrocardiograms (ECGs) are presented.

  9. Results of conservative surgery and radiation therapy for breast cancer

    SciTech Connect

    Osteen, R.T.; Smith, B.L. )

    1990-10-01

    For stage I or II breast cancer, conservative surgery and radiation therapy are as effective as modified radical or radical mastectomy. In most cases, cosmetic considerations and the availability of therapy are the primary concerns. The extent of a surgical resection less than a mastectomy has not been a subject of a randomized trial and is controversial. It appears that removal of a quadrant of the breast for small lesions is safe but excessive. It may be possible to limit the breast resection to gross tumor removal for most patients while using wider resections for patients with an extensive intraductal component or for invasive lobular carcinoma. It also appears that excluding patients from breast conservation on the basis of positive margins on the first attempt at tumor excision may be unnecessarily restrictive. Although patients with an extensive intraductal component or invasive lobular carcinoma should have negative margins, it appears that a patient with predominantly invasive ductal carcinoma can be treated without re-excision if all gross tumor has been resected and there is no reason to suspect extensive microscopic disease. Patients with indeterminate margins should have a re-excision. Axillary dissection provides prognostic information and prevents progression of the disease within the axilla. Axillary dissections limited to level I will accurately identify a substantial number of patients who have pathologically positive but clinically negative nodes. When combined with radiation therapy to the axilla, a level I dissection results in a limited number of patients with progressive axillary disease. Patients with pathologically positive axillas and patients at particularly high risk for systemic disease because of the extent of axillary node involvement can be identified by dissections of levels I and II. 60 references.

  10. Radiation Therapy Alone for Imaging-Defined Meningiomas

    SciTech Connect

    Korah, Mariam P.; Nowlan, Adam W.; Johnstone, Peter A.S.; Crocker, Ian R.

    2010-01-15

    Purpose: To assess local control and treatment-related toxicity of single-modality radiation therapy (RT) in the treatment of imaging-defined meningiomas. Methods and Materials: The records of Emory University School of Medicine, Atlanta, GA, were reviewed between 1985 and 2003. We identified 41 patients with 42 meningiomas treated with RT alone for lesions diagnosed on imaging alone. No patients received a histologic diagnosis. Patients in whom there was uniform agreement that the tumor represented a meningioma were accepted for therapy. Of the patients, 22 were treated with stereotactic radiosurgery (SRS), 11 with fractionated stereotactic radiotherapy (FSR), and 9 with three-dimensional conformal therapy (3DCRT). The median doses of SRS, FSR, and 3DCRT were 14 Gy, 50.4 Gy, and 52.2 Gy, respectively. Results: Median follow-up was 60 months. Of 42 meningiomas, 39 were locally controlled. The 8-year actuarial local control rate by Kaplan-Meier methods was 94%. One failure occurred 6 months after 3DCRT, a second at 34 months after FSR, and a third at 125 months after SRS. A temporary symptomatic radiation-related neurologic sequela developed in 1 patient treated with SRS. No fatal treatment complications occurred. The 8-year rate for actuarial freedom from complication survival by Kaplan-Meier methods was 97%. Conclusions: RT alone is an attractive alternative to surgery for imaging-defined meningiomas without significant mass effect. It offers local control comparable to surgical resection with minimal morbidity. RT should be considered as a viable alternative to surgery for tumors in various locations.

  11. Aetiology of pleural plaques

    PubMed Central

    Rous, V.; Studeny, J.

    1970-01-01

    Pleural plaques were found in 644 (6·6%) of 9,760 photofluorograms taken in 1965 in a region of Pelhřimov district; the incidence was highest in the age group 66-70 years. The advanced age of those affected may be explained by the greater frequency of the causative agent in the past. The disorder was known in Pelhřimov district as early as 1930; it was then thought to be posttuberculous. The past history of the cases was uninformative; as a rule, the only common previous disease was pleurisy with effusion, occurring in 9·7%. The general condition of those affected was excellent; only 8% were aware of the fact that pleural lesions were present. The disorder was found mainly in farmers, familial incidence was common, and if two generations of one family suffered from the condition, the older generation was affected in 100%. Pleural plaques consist morphologically of limited areas of hyalinized collagenous connective tissue with calcium salt deposits. Tubercle bacilli could not be cultivated from the lesions. Mineralological analysis showed no evidence of silicates in the pleural plaques and a normal content in the lungs. The aetiological factor responsible for the development of pleural plaques in Pelhřimov district is not known, but asbestos cannot be implicated. The unknown noxious agent is carried to the pleura by the lymph and blood stream. Pleural plaques are an endemic disorder. The traditional view that lesions are post-tuberculous appears, in the region submitted to this study, to be a possible explanation. Images PMID:5465601

  12. Association between Randall's Plaque and Calcifying Nanoparticles

    NASA Technical Reports Server (NTRS)

    Ciftcioglu, Neva; Vejdani, Kaveh; Lee, Olivia; Mathew, Grace; Aho, Katja M.; Kajander, Olavi; McKay, David S.; Jones, Jeff A.; Hayat, Matthew; Stoller, Marshall L.

    2007-01-01

    Randall's plaques, first described by Alexander Randall in the 1930s, are small subepithelial calcifications in the renal papillae (RP) that also extend deeply into the renal medulla. Despite the strong correlation between the presence of these plaques and the formation of renal stones, the precise origin and pathogenesis of Randall s plaque formation remain elusive. The discovery of calcifying nanoparticles (CNP) and their detection in many calcifying processes of human tissues has raised hypotheses about their possible involvement in renal stone formation. We collected RP and blood samples from 17 human patients who had undergone laparoscopic nephrectomy due to neoplasia. Homogenized RP tissues and serum samples were cultured for CNP. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis were performed on fixed RP samples. Immunohistochemical staining (IHS) was applied on the tissue samples using CNP-specific monoclonal antibody (mAb). Randall s plaques were visible on gross inspection in 11 out of 17 collected samples. Cultures of all serum samples and 13 tissue homogenates had CNP growth within 4 weeks. SEM revealed spherical apatite formations in 14 samples, with calcium and phosphate peaks detected by EDS analysis. IHS was positive in 9 out of 17 samples. A strong link was found between the presence of Randall s plaques and the detection of CNP, also referred to as nanobacteria. These results suggest new insights into the etiology of Randall's plaque formation, and will help us understand the pathogenesis of stone formation. Further studies on this topic may lead us to new approaches on early diagnosis and novel medical therapies of kidney stone formation.

  13. Predictors of overall satisfaction of cancer patients undergoing radiation therapy

    PubMed Central

    Becker-Schiebe, Martina; Pinkert, Uwe; Ahmad, Tahera; Schäfer, Christof; Hoffmann, Wolfgang; Franz, Heiko

    2015-01-01

    Background Reporting the experiences and satisfaction of patients, as well as their quality of care scores is an emerging recommendation in health care systems. Many aspects of patients’ experience determine their overall satisfaction. The aim of this evaluation was to define the main factors contributing to the satisfaction of patients undergoing radiotherapy in an outpatient setting. Patients and methods A total of 1,710 patients with a histologically proven cancer, who were treated in our department between 2012 and 2014, were recruited for this prospective evaluation. At the end of therapy, each patient was asked to grade the skills and the care provided by radiation therapists, physicians, and physician’s assistants, as well as the overall satisfaction during therapy. Statistical analysis was performed to determine which parameters had the greatest influence on overall satisfaction. Results Overall satisfaction with the provided care was high with a mean satisfaction score of 1.4. Significant correlations were found between overall satisfaction and each of the following survey items: courtesy, protection of privacy, professional skills and care provided by the radiation therapists and physicians, accuracy of provided information, and cleanliness. Linear regression analysis demonstrated that courteous behavior and the protection of privacy were the strongest predictors for overall satisfaction (P<0.001), followed by care and skills of physicians and radiation therapists. Patients suffering from head and neck cancer expressed lower overall satisfaction. Conclusion Based on our prospectively acquired data, we were able to identify and confirm key factors for patient satisfaction in an outpatient radiooncological cancer center. From these results, we conclude that patients want most importantly to be treated with courtesy, protection of privacy and care. PMID:26491266

  14. Molecular Pathways: Targeted α-Particle Radiation Therapy

    PubMed Central

    Baidoo, Kwamena E.; Yong, Kwon; Brechbiel, Martin W.

    2012-01-01

    An α-particle, a 4He nucleus, is exquisitely cytotoxic, and indifferent to many limitations associated with conventional chemo- and radiotherapy. The exquisite cytotoxicity of α radiation, the result of its high mean energy deposition (high linear energy transfer, LET) and limited range in tissue, provides for a highly controlled therapeutic modality that can be targeted to selected malignant cells (targeted α-therapy (TAT)) with minimal normal tissue effects. There is a burgeoning interest in the development of TAT that is buoyed by the increasing number of ongoing clinical trials worldwide. The short path length renders α-emitters suitable for treatment and management of minimal disease such as micrometastases or residual tumor after surgical debulking, hematological cancers, infections, and compartmental cancers such as ovarian cancer or neoplastic meningitis. Yet, despite decades of study of high-LET radiation, the mechanistic pathways of the effects of this modality remain not well defined. The modality is effectively presumed to follow a simple therapeutic mechanism centered on catastrophic double strand (ds) DNA breaks without full examination of the actual molecular pathways and targets that are activated that directly impact cell survival or death. This Molecular Pathways article provides an overview of the mechanisms and pathways that are involved in the response to and repair of TAT induced DNA damage as currently understood. Finally, this article highlights the current state of clinical translation of TAT as well as other high-LET radionuclide radiation therapy using α-emitters such as 225Ac, 211At, 213Bi, 212Pb and 223Ra. PMID:23230321

  15. Novel Multicompartment 3-Dimensional Radiochromic Radiation Dosimeters for Nanoparticle-Enhanced Radiation Therapy Dosimetry

    SciTech Connect

    Alqathami, Mamdooh; Blencowe, Anton; Yeo, Un Jin; Doran, Simon J.; Qiao, Greg; Geso, Moshi

    2012-11-15

    Purpose: Gold nanoparticles (AuNps), because of their high atomic number (Z), have been demonstrated to absorb low-energy X-rays preferentially, compared with tissue, and may be used to achieve localized radiation dose enhancement in tumors. The purpose of this study is to introduce the first example of a novel multicompartment radiochromic radiation dosimeter and to demonstrate its applicability for 3-dimensional (3D) dosimetry of nanoparticle-enhanced radiation therapy. Methods and Materials: A novel multicompartment phantom radiochromic dosimeter was developed. It was designed and formulated to mimic a tumor loaded with AuNps (50 nm in diameter) at a concentration of 0.5 mM, surrounded by normal tissues. The novel dosimeter is referred to as the Sensitivity Modulated Advanced Radiation Therapy (SMART) dosimeter. The dosimeters were irradiated with 100-kV and 6-MV X-ray energies. Dose enhancement produced from the interaction of X-rays with AuNps was calculated using spectrophotometric and cone-beam optical computed tomography scanning by quantitatively comparing the change in optical density and 3D datasets of the dosimetric measurements between the tissue-equivalent (TE) and TE/AuNps compartments. The interbatch and intrabatch variability and the postresponse stability of the dosimeters with AuNps were also assessed. Results: Radiation dose enhancement factors of 1.77 and 1.11 were obtained using 100-kV and 6-MV X-ray energies, respectively. The results of this study are in good agreement with previous observations; however, for the first time we provide direct experimental confirmation and 3D visualization of the radiosensitization effect of AuNps. The dosimeters with AuNps showed small (<3.5%) interbatch variability and negligible (<0.5%) intrabatch variability. Conclusions: The SMART dosimeter yields experimental insights concerning the spatial distributions and elevated dose in nanoparticle-enhanced radiation therapy, which cannot be performed using any of the current methods. The authors concluded that it can be used as a novel independent method for nanoparticle-enhanced radiation therapy dosimetry.

  16. Skeletal sequelae of radiation therapy for malignant childhood tumors

    SciTech Connect

    Butler, M.S.; Robertson, W.W. Jr.; Rate, W.; D'Angio, G.J.; Drummond, D.S. )

    1990-02-01

    One hundred forty-three patients who received radiation therapy for childhood tumors, and survived to the age of skeletal maturity, were studied by retrospective review of oncology records and roentgenograms. Diagnoses for the patients were the following: Hodgkin's lymphoma (44), Wilms's tumor (30), acute lymphocytic leukemia (26), non-Hodgkin's lymphoma (18), Ewing's sarcoma (nine), rhabdomyosarcoma (six), neuroblastoma (six), and others (four). Age at the follow-up examination averaged 18 years (range, 14-28 years). Average length of follow-up study was 9.9 years (range, two to 18 years). Asymmetry of the chest and ribs was seen in 51 (36%) of these children. Fifty (35%) had scoliosis; 14 had kyphosis. In two children, the scoliosis was treated with a brace, while one developed significant kyphosing scoliosis after laminectomy and had spinal fusion. Twenty-three (16%) patients complained of significant pain at the radiation sites. Twelve of the patients developed leg-length inequality; eight of those were symptomatic. Three patients developed second primary tumors. Currently, the incidence of significant skeletal sequelae is lower and the manifestations are less severe than reported in the years from 1940 to 1970. The reduction in skeletal complications may be attributed to shielding of growth centers, symmetric field selection, decreased total radiation doses, and sequence changes in chemotherapy.

  17. Therapeutic Implications for Overcoming Radiation Resistance in Cancer Therapy

    PubMed Central

    Kim, Byeong Mo; Hong, Yunkyung; Lee, Seunghoon; Liu, Pengda; Lim, Ji Hong; Lee, Yong Heon; Lee, Tae Ho; Chang, Kyu Tae; Hong, Yonggeun

    2015-01-01

    Ionizing radiation (IR), such as X-rays and gamma (γ)-rays, mediates various forms of cancer cell death such as apoptosis, necrosis, autophagy, mitotic catastrophe, and senescence. Among them, apoptosis and mitotic catastrophe are the main mechanisms of IR action. DNA damage and genomic instability contribute to IR-induced cancer cell death. Although IR therapy may be curative in a number of cancer types, the resistance of cancer cells to radiation remains a major therapeutic problem. In this review, we describe the morphological and molecular aspects of various IR-induced types of cell death. We also discuss cytogenetic variations representative of IR-induced DNA damage and genomic instability. Most importantly, we focus on several pathways and their associated marker proteins responsible for cancer resistance and its therapeutic implications in terms of cancer cell death of various types and characteristics. Finally, we propose radiation-sensitization strategies, such as the modification of fractionation, inflammation, and hypoxia and the combined treatment, that can counteract the resistance of tumors to IR. PMID:26569225

  18. Ultrasound Thermometry for Therapy-level Radiation Dosimetry

    NASA Astrophysics Data System (ADS)

    Taylor, Courtney

    2010-03-01

    Radiation oncology is the process of administering a specified dose of radiation to a patient currently receiving treatment for a form of cancer. In this process, it is vital to know the delivered dose for a given radiation beam to correctly treat a patient. The primary reference standard for absorbed dose is established using water calorimetry. The absorbed dose, typically of order 1 Gy (J/kg) at therapy levels, is realized by measuring sub-millikelvin temperature changes using a thermistor in a sensitive Wheatstone bridge. Ultrasound technology has been investigated as an alternative to thermistor measurements since the speed of sound propagation in water varies with temperature. With ultrasonic time-of-flight and highly sensitive phase detection techniques, temperature sensitivity comparable to that of the thermistor bridge has been achieved without introducing non-water materials into the test area. A single ultrasound transducer transmitting and receiving at 5.0 MHz throughout the length of the water phantom, and the phase change of the sound wave was used to determine temperature increase from an irradiative source at specified depths of the phantom. In this experiment, the exposure period was varied from 15s to 160s cyclically by modulating a heat lamp, and a profile of the measured temperature response as a function of the period was obtained using Fourier analysis. Due to the large temperature gradient in the water phantom, measurements are prone to convection which was indeed observed and will be discussed.

  19. Combination Regimens of Radiation Therapy and Therapeutic Cancer Vaccines: Mechanisms and Opportunities

    PubMed Central

    Garnett-Benson, Charlie; Hodge, James W.; Gameiro, Sofia R.

    2014-01-01

    Radiation therapy is widely used with curative or palliative intent in the clinical management of multiple cancers. Although mainly aimed at direct tumor cell killing, mounting evidence suggests that radiation can alter the tumor to become an immunostimulatory milieu. Data suggest that the immunogenic effects of radiation can be exploited to promote synergistic antitumor effects in combination with immunotherapeutic agents. Here we review concepts associated with the immunogenic consequences of radiation therapy, and highlight how preclinical findings are translating into clinical benefit for patients receiving combination regimens of radiation therapy and therapeutic cancer vaccines. PMID:25481266

  20. Hyperbaric Oxygen Therapy in Treating Long-Term Gastrointestinal Adverse Effects Caused by Radiation Therapy in Patients With Pelvic Cancer

    ClinicalTrials.gov

    2011-07-14

    Bladder Cancer; Cervical Cancer; Colorectal Cancer; Endometrial Cancer; Gastrointestinal Complications; Long-term Effects Secondary to Cancer Therapy in Adults; Ovarian Cancer; Prostate Cancer; Radiation Toxicity; Sarcoma; Testicular Germ Cell Tumor; Vaginal Cancer

  1. Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

    NASA Technical Reports Server (NTRS)

    Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

    2006-01-01

    Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low-dose-rate dose to the bone marrow (mean = 2.5 Gy) was consistent with the measured ERR (0.62, 95% Cl =-0.2 to 1.9). Conclusions: An extended, biologically based model for leukemia that includes HSC initiation, inactivation, proliferation, and, uniquely for leukemia, long-range HSC migration predicts, %Kith reasonable accuracy, risks for radiationinduced leukemia associated with exposure to therapeutic doses of radiation.

  2. American Society of Radiation Oncology Recommendations for Documenting Intensity-Modulated Radiation Therapy Treatments

    SciTech Connect

    Holmes, Timothy Das, Rupak; Low, Daniel; Yin Fangfang; Balter, James; Palta, Jatinder; Eifel, Patricia

    2009-08-01

    Despite the widespread use of intensity-modulated radiation therapy (IMRT) for approximately a decade, a lack of adequate guidelines for documenting these treatments persists. Proper IMRT treatment documentation is necessary for accurate reconstruction of prior treatments when a patient presents with a marginal recurrence. This is especially crucial when the follow-up care is managed at a second treatment facility not involved in the initial IMRT treatment. To address this issue, an American Society for Radiation Oncology (ASTRO) workgroup within the American ASTRO Radiation Physics Committee was formed at the request of the ASTRO Research Council to develop a set of recommendations for documenting IMRT treatments. This document provides a set of comprehensive recommendations for documenting IMRT treatments, as well as image-guidance procedures, with example forms provided.

  3. American Society of Radiation Oncology recommendations for documenting intensity-modulated radiation therapy treatments.

    PubMed

    Holmes, Timothy; Das, Rupak; Low, Daniel; Yin, Fang-Fang; Balter, James; Palta, Jatinder; Eifel, Patricia

    2009-08-01

    Despite the widespread use of intensity-modulated radiation therapy (IMRT) for approximately a decade, a lack of adequate guidelines for documenting these treatments persists. Proper IMRT treatment documentation is necessary for accurate reconstruction of prior treatments when a patient presents with a marginal recurrence. This is especially crucial when the follow-up care is managed at a second treatment facility not involved in the initial IMRT treatment. To address this issue, an American Society for Radiation Oncology (ASTRO) workgroup within the American ASTRO Radiation Physics Committee was formed at the request of the ASTRO Research Council to develop a set of recommendations for documenting IMRT treatments. This document provides a set of comprehensive recommendations for documenting IMRT treatments, as well as image-guidance procedures, with example forms provided. PMID:19616738

  4. Scatter correction for cone-beam CT in radiation therapy

    SciTech Connect

    Zhu Lei; Xie Yaoqin; Wang Jing; Xing Lei

    2009-06-15

    Cone-beam CT (CBCT) is being increasingly used in modern radiation therapy for patient setup and adaptive replanning. However, due to the large volume of x-ray illumination, scatter becomes a rather serious problem and is considered as one of the fundamental limitations of CBCT image quality. Many scatter correction algorithms have been proposed in literature, while a standard practical solution still remains elusive. In radiation therapy, the same patient is scanned repetitively during a course of treatment, a natural question to ask is whether one can obtain the scatter distribution on the first day of treatment and then use the data for scatter correction in the subsequent scans on different days. To realize this scatter removal scheme, two technical pieces must be in place: (i) A strategy to obtain the scatter distribution in on-board CBCT imaging and (ii) a method to spatially match a prior scatter distribution with the on-treatment CBCT projection data for scatter subtraction. In this work, simple solutions to the two problems are provided. A partially blocked CBCT is used to extract the scatter distribution. The x-ray beam blocker has a strip pattern, such that partial volume can still be accurately reconstructed and the whole-field scatter distribution can be estimated from the detected signals in the shadow regions using interpolation/extrapolation. In the subsequent scans, the patient transformation is determined using a rigid registration of the conventional CBCT and the prior partial CBCT. From the derived patient transformation, the measured scatter is then modified to adapt the new on-treatment patient geometry for scatter correction. The proposed method is evaluated using physical experiments on a clinical CBCT system. On the Catphan(c)600 phantom, the errors in Hounsfield unit (HU) in the selected regions of interest are reduced from about 350 to below 50 HU; on an anthropomorphic phantom, the error is reduced from 15.7% to 5.4%. The proposed method is attractive in applications where a high CBCT image quality is critical, for example, dose calculation in adaptive radiation therapy.

  5. Combinations of radiation therapy and immunotherapy for melanoma: a review of clinical outcomes.

    PubMed

    Barker, Christopher A; Postow, Michael A

    2014-04-01

    Radiation therapy has long played a role in the management of melanoma. Recent advances have also demonstrated the efficacy of immunotherapy in the treatment of melanoma. Preclinical data suggest a biologic interaction between radiation therapy and immunotherapy. Several clinical studies corroborate these findings. This review will summarize the outcomes of studies reporting on patients with melanoma treated with a combination of radiation therapy and immunotherapy. Vaccine therapies often use irradiated melanoma cells, and may be enhanced by radiation therapy. The cytokines interferon-α and interleukin-2 have been combined with radiation therapy in several small studies, with some evidence suggesting increased toxicity and/or efficacy. Ipilimumab, a monoclonal antibody which blocks cytotoxic T-lymphocyte antigen-4, has been combined with radiation therapy in several notable case studies and series. Finally, pilot studies of adoptive cell transfer have suggested that radiation therapy may improve the efficacy of treatment. The review will demonstrate that the combination of radiation therapy and immunotherapy has been reported in several notable case studies, series and clinical trials. These clinical results suggest interaction and the need for further study. PMID:24661650

  6. Combinations of Radiation Therapy and Immunotherapy for Melanoma: A Review of Clinical Outcomes

    SciTech Connect

    Barker, Christopher A.; Postow, Michael A.

    2014-04-01

    Radiation therapy has long played a role in the management of melanoma. Recent advances have also demonstrated the efficacy of immunotherapy in the treatment of melanoma. Preclinical data suggest a biologic interaction between radiation therapy and immunotherapy. Several clinical studies corroborate these findings. This review will summarize the outcomes of studies reporting on patients with melanoma treated with a combination of radiation therapy and immunotherapy. Vaccine therapies often use irradiated melanoma cells, and may be enhanced by radiation therapy. The cytokines interferon-α and interleukin-2 have been combined with radiation therapy in several small studies, with some evidence suggesting increased toxicity and/or efficacy. Ipilimumab, a monoclonal antibody which blocks cytotoxic T-lymphocyte antigen-4, has been combined with radiation therapy in several notable case studies and series. Finally, pilot studies of adoptive cell transfer have suggested that radiation therapy may improve the efficacy of treatment. The review will demonstrate that the combination of radiation therapy and immunotherapy has been reported in several notable case studies, series and clinical trials. These clinical results suggest interaction and the need for further study.

  7. Clinical studies on the use of radiation therapy as primary treatment of early breast cancer

    SciTech Connect

    Harris, J.R.; Beadle, G.F.; Hellman, S.

    1984-02-01

    The treatment of operable breast cancer by primary radiation therapy instead of mastectomy is undergoing evaluation in the United States and Europe. Retrospective studies of patients treated by primary radiation therapy show that local control and survival rates are comparable to those obtained by mastectomy. Detailed analysis of local failure following primary radiation therapy indicates the importance of excisional biopsy of the primary tumor, moderate doses of radiation to the breast and draining lymph node areas, and the use of a boost to the primary tumor area in maximizing local control. Further, the judicious use of local excision combined with meticulous radiotherapy technique yields highly satisfactory results for the majority of treated patients. Preliminary results from prospective trials also indicate that primary radiation therapy provides both local control and survival rates equivalent to mastectomy. Primary radiation therapy is becoming an increasingly important alternative to mastectomy where surgical and radiotherapeutic expertise are available to optimize both local tumor control and the final cosmetic outcome.

  8. Has the use of computers in radiation therapy improved the accuracy in radiation dose delivery?

    NASA Astrophysics Data System (ADS)

    Van Dyk, J.; Battista, J.

    2014-03-01

    Purpose: It is well recognized that computer technology has had a major impact on the practice of radiation oncology. This paper addresses the question as to how these computer advances have specifically impacted the accuracy of radiation dose delivery to the patient. Methods: A review was undertaken of all the key steps in the radiation treatment process ranging from machine calibration to patient treatment verification and irradiation. Using a semi-quantitative scale, each stage in the process was analysed from the point of view of gains in treatment accuracy. Results: Our critical review indicated that computerization related to digital medical imaging (ranging from target volume localization, to treatment planning, to image-guided treatment) has had the most significant impact on the accuracy of radiation treatment. Conversely, the premature adoption of intensity-modulated radiation therapy has actually degraded the accuracy of dose delivery compared to 3-D conformal radiation therapy. While computational power has improved dose calibration accuracy through Monte Carlo simulations of dosimeter response parameters, the overall impact in terms of percent improvement is relatively small compared to the improvements accrued from 3-D/4-D imaging. Conclusions: As a result of computer applications, we are better able to see and track the internal anatomy of the patient before, during and after treatment. This has yielded the most significant enhancement to the knowledge of "in vivo" dose distributions in the patient. Furthermore, a much richer set of 3-D/4-D co-registered dose-image data is thus becoming available for retrospective analysis of radiobiological and clinical responses.

  9. Application of infrared fiber optic imaging in atherosclerotic plaques

    NASA Astrophysics Data System (ADS)

    Guo, Bujin; Casscells, S. W.; Bearman, Gregory H.; McNatt, Janice; Naghevi, Morteza; Malik, Basit A.; Gul, Khawar; Willerson, James T.

    1999-07-01

    Rupture of atherosclerotic plaques - the main cause of heart attach and stokes - is not predictable. Hence even treadmill stress tests fail to detect many persons at risk. Fatal plaques are found at autopsies to be associated with active inflammatory cells. Classically, inflammation is detected by its swelling, red color, pain and heat. We have found that heat accurately locates the dangerous plaques that are significantly warmer then atherosclerotic plaques without the same inflammation. In order to develop a non-surgical method of locating these plaques, an IR fiber optic imaging system has been developed in our laboratory to evalute the causes and effect of heat in atherosclerotic plaques. The fiber optical imagin bundle consists of 900 individual As2S3 chalcogenide glass fibers which transmit IR radiation from 0.7 micrometers 7 micrometers with little energy loss. By combining that with a highly sensitive Indium Antimonide IR focal plane array detector, we are able to obtain thermal graphic images in situ. The temperature heterogeneity of atherosclerotic plaques developed in the arteral of the experimental animal models is under study with the new device. The preliminary experimental results from the animal model are encouraging. The potential of using this new technology in diagnostic evaluation of the vulnerable atherosclerotic plaques is considerable.

  10. Intraoperative radiation therapy using mobile electron linear accelerators: report of AAPM Radiation Therapy Committee Task Group No. 72.

    PubMed

    Beddar, A Sam; Biggs, Peter J; Chang, Sha; Ezzell, Gary A; Faddegon, Bruce A; Hensley, Frank W; Mills, Michael D

    2006-05-01

    Intraoperative radiation therapy (IORT) has been customarily performed either in a shielded operating suite located in the operating room (OR) or in a shielded treatment room located within the Department of Radiation Oncology. In both cases, this cancer treatment modality uses stationary linear accelerators. With the development of new technology, mobile linear accelerators have recently become available for IORT. Mobility offers flexibility in treatment location and is leading to a renewed interest in IORT. These mobile accelerator units, which can be transported any day of use to almost any location within a hospital setting, are assembled in a nondedicated environment and used to deliver IORT. Numerous aspects of the design of these new units differ from that of conventional linear accelerators. The scope of this Task Group (TG-72) will focus on items that particularly apply to mobile IORT electron systems. More specifically, the charges to this Task Group are to (i) identify the key differences between stationary and mobile electron linear accelerators used for IORT, (ii) describe and recommend the implementation of an IORT program within the OR environment, (iii) present and discuss radiation protection issues and consequences of working within a nondedicated radiotherapy environment, (iv) describe and recommend the acceptance and machine commissioning of items that are specific to mobile electron linear accelerators, and (v) design and recommend an efficient quality assurance program for mobile systems. PMID:16752582

  11. Cancer of the glottis: prognostic factors in radiation therapy

    SciTech Connect

    Mantravadi, R.V.; Liebner, E.J.; Haas, R.E.; Skolnik, E.M.; Applebaum, E.L.

    1983-10-01

    The authors conducted a multivariate analysis of the prognostic factors in 96 patients with early glottic cancer treated by radiation therapy. Of these, 73 had T1 and 23 had T2 tumor. The primary tumor was controlled in 82% of T1 and 74% of T2 lesions. Actuarial five-year survival rates were 87% for T1 and 74% for T2. Carcinoma of the anterior commissure associated with bilateral vocal cord involvement, subglottic tumor extension, persistent or recurrent laryngeal edema, and impaired cord mobility was found to adversely influence the prognosis. The data suggest that irradiation is the treatment of choice for glottic cancer limited to the vocal cords or with minimal extension to the anterior commissure or supraglottic larynx.

  12. Cancer of the glottis: prognostic factors in radiation therapy

    SciTech Connect

    Mantravadi, R.V.P.; Liebner, E.J.; Haas, R.E.; Skolnik, E.M.; Applebaum, E.L.

    1983-10-01

    The authors conducted a multivariate analysis of the prognostic factors in 96 patients with early glottic cancer treated by radiation therapy. Of these, 73 had T/sub 1/ and 23 had T/sub 2/ tumor. The primary tumor was controlled in 82% of T/sub 1/ amd 74% for T/sub 2/. Carcinoma of the anterior commissure associated with bilateral vocal cord involvement, subglottic tumor extension, persistent or recurrent laryngeal edema, and impaired cord mobility was found to adversely influence the prognosis. The data suggest that irradiation is the treatment of choice for glottic cancer limited to the vocal cords or with minimal extension to the anterior commissure or gupraglottic larynx.

  13. Role of external radiation therapy in urinary cancers.

    PubMed

    Parisi, S; Troiano, M; Corsa, P; Raguso, A; Cossa, S; Piazzolla, E E; Munafò, T; Sanpaolo, G; Natuno, A; Maiello, E

    2007-06-01

    Invasive urinary tumors are relatively rare and their treatment may cause important changes in urinary, sexual, and social functions. A systematic review of external radiation therapy studies in urinary cancers has been carried out. This synthesis of the literature is based on data from meta-analysis, randomized and prospective trials, and retrospective studies. There are few controlled clinical trials using adjuvant or radical radiotherapy +/- chemotherapy in kidney, ureter, and urethra cancers; there are several reports of muscle-invasive bladder cancer using multimodality treatment: intravesical surgery and neo-adjuvant chemotherapy to radiotherapy or concomitant radiochemotherapy with organ preservation. The conclusions reached for renal cancer are controversial; urethra and ureter cancers data are few and inconclusive; sufficient data now exist in literature to demonstrate that conservative management with organ preservation, for muscle-invasive bladder cancer, is a valid alternative to radical cystectomy, viewed as the gold standard. PMID:17591812

  14. Effects of radiation therapy on skeletal growth in childhood

    SciTech Connect

    Goldwein, J.W. )

    1991-01-01

    Ionizing radiation was used to treat childhood cancer long before the advent of chemotherapy, and it took little time for physicians to appreciate the deleterious effects it had on skeletal growth. The cause of this complication results predominantly from alteration of chondroblastic activity. This may stem directly from irradiation at the epiphyseal plate or indirectly from irradiation of glands that secrete growth-mediating hormones. The complication can go far beyond the obvious physical afflictions and extend into the psychologic domain, rendering deeper, more permanent scars. Presently, many of these effects are predictable, reducible, and treatable without compromising the cure that so often depends on the use of irradiation. Because of the complexities of childhood cancer therapy, strategies aimed at diminishing these effects are challenging. It is imperative that these effects be understood so that they can be reduced in current patients and prevented in future patients.33 references.

  15. Radiation Therapy Oncology Group clinical trials with misonidazole

    SciTech Connect

    Wasserman, T.H.; Stetz, J.; Phillips, T.L.

    1981-05-15

    This paper presents a review of the progressive clinical trials of the hypoxic cell radiosensitizer, misonidazole, in the Radiation Therapy Oncology Group (RTOG). Presentation is made of all the schemas of the recently completed and currently active RTOG Phase II and Phase III studies. Detailed information is provided on the clinical toxicity of the Phase II trials, specifically regarding neurotoxicity. With limitations in drug total dose, a variety of dose schedules have proven to be tolerable, with a moderate incidence of nausea and vomiting and mild peripheral neuropathy or central neuropathy. No other organ toxicity has been seen, specifically no liver, renal or bone marrow toxicities. An additional Phase III malignant glioma trial in the Brain Tumor Study Group is described.

  16. Carcinoma of the nasal vestibule treated with radiation therapy

    SciTech Connect

    Mendenhall, N.P.; Parsons, J.T.; Cassisi, N.J.; Million, R.R.

    1987-05-01

    Twenty-two patients with squamous carcinoma of the nasal vestibule were treated at the University of Florida Division of Radiation Therapy with curative intent. Fifteen lesions were de novo and seven recurrent after surgery. By AJCC classification, 7 lesions were Tx or T1, 2 were T2, 2 were T3, and 11 were T4. Management of the primary tumor and regional lymphatic drainage was highly individualized. Local control was achieved in 19 out of 22 lesions. The ultimate regional lymph node control rate was 22 out of 22, although two patients required radical neck dissection after development of lymph node disease in untreated regional lymphatics. Two patients have died of cancer and three of intercurrent disease. Cosmetic results are generally excellent but may be compromised by previous surgery in recurrent lesions or tumor destruction of normal tissues in advanced lesions. Complications of treatment are minimal.

  17. Nanoparticles for Radiation Therapy Enhancement: the Key Parameters

    PubMed Central

    Retif, Paul; Pinel, Sophie; Toussaint, Magali; Frochot, Céline; Chouikrat, Rima; Bastogne, Thierry; Barberi-Heyob, Muriel

    2015-01-01

    This review focuses on the radiosensitization strategies that use high-Z nanoparticles. It does not establish an exhaustive list of the works in this field but rather propose constructive criticisms pointing out critical factors that could improve the nano-radiation therapy. Whereas most reviews show the chemists and/or biologists points of view, the present analysis is also seen through the prism of the medical physicist. In particular, we described and evaluated the influence of X-rays energy spectra using a numerical analysis. We observed a lack of standardization in preclinical studies that could partially explain the low number of translation to clinical applications for this innovative therapeutic strategy. Pointing out the critical parameters of high-Z nanoparticles radiosensitization, this review is expected to contribute to a larger preclinical and clinical development. PMID:26155318

  18. Implementation of Image-Guidance Techniques in Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Thomas, Michael; Clark, Brenda; MacPherson, Miller; Montgomery, Lynn; Gerig, Lee

    2008-06-01

    For more than 100 years, physicists have been a vital part of the medical team required to deliver radiation therapy. Their role encompasses the verification of dose accuracy to the development and implementation of new techniques, the most recent of which is the incorporation of daily image guidance to account for inter- and intra-fraction target changes. For example, computed tomography (CT) integrated into radiotherapy treatment units allows the image-guided treatment of the prostate where the target location depends on the degree of rectal filling--a parameter that changes on timescales from minutes to weeks. Different technology is required for the adequate treatment of small lung tumours since respiration occurs on timescales of seconds. This presentation will review current image-guided techniques.

  19. X-ray energy optimization in minibeam radiation therapy

    SciTech Connect

    Prezado, Y.; Thengumpallil, S.; Renier, M.; Bravin, A.

    2009-11-15

    Purpose: The purpose of this work is to assess which energy in minibeam radiation therapy provides the best compromise between the deposited dose in the tumor and the sparing of the healthy tissues. Methods: Monte Carlo simulations (PENELOPE 2006) have been used as a method to calculate the ratio of the peak-to-valley doses (PVDR) in the healthy tissues and in the tumor for different beam energies. The maximization of the ratio of PVDR in the healthy tissues and in the tumor has been used as a criterion. Results: The main result of this work is that, for the parameters being used in preclinical trials (minibeam sizes of 600 {mu}m and 1200 {mu}m center-to-center separation), the optimum beam energy is 375 keV. Conclusions: The conclusion is that this is the energy of minibeams that should be used in the preclinical studies.

  20. [Equipment and positioning technologies in stereotactic body radiation therapy].

    PubMed

    Marchesi, V; Dedieu, V; Lacornerie, T; Buchheit, I

    2014-01-01

    Strereotactic body radiation therapy needs adapted or dedicated equipment to allow fulfilling the particular conditions of the stereotactic treatments: submillimetric accuracy during the treatment delivery, high doses for a reduced number of sessions. This kind of treatment can be either performed using delivery equipment conceived and dedicated to the technique, or performed on conventional machines adapted to meet the criteria. Contrary to intracranial treatments, the positioning of the target volume raises new difficulties, mainly due to the diversity of localization to treat and also due to inter- and intrafraction movements that can occur. To reduce these effects that could affect the irradiation accuracy, positioning or movement compensation, mostly due to respiration, tools have been developed. PMID:24837350

  1. Low Level Laser Therapy: laser radiation absorption in biological tissues

    NASA Astrophysics Data System (ADS)

    Di Giacomo, Paola; Orlando, Stefano; Dell'Ariccia, Marco; Brandimarte, Bruno

    2013-07-01

    In this paper we report the results of an experimental study in which we have measured the transmitted laser radiation through dead biological tissues of various animals (chicken, adult and young bovine, pig) in order to evaluate the maximum thickness through which the power density could still produce a reparative cellular effect. In our experiments we have utilized a pulsed laser IRL1 ISO model (based on an infrared diode GaAs, ?=904 nm) produced by BIOMEDICA s.r.l. commonly used in Low Level Laser Therapy. Some of the laser characteristics have been accurately studied and reported in this paper. The transmission results suggest that even with tissue thicknesses of several centimeters the power density is still sufficient to produce a cell reparative effect.

  2. Automatic CT simulation optimization for radiation therapy: A general strategy

    SciTech Connect

    Li, Hua Chen, Hsin-Chen; Tan, Jun; Gay, Hiram; Michalski, Jeff M.; Mutic, Sasa; Yu, Lifeng; Anastasio, Mark A.; Low, Daniel A.

    2014-03-15

    Purpose: In radiation therapy, x-ray computed tomography (CT) simulation protocol specifications should be driven by the treatment planning requirements in lieu of duplicating diagnostic CT screening protocols. The purpose of this study was to develop a general strategy that allows for automatically, prospectively, and objectively determining the optimal patient-specific CT simulation protocols based on radiation-therapy goals, namely, maintenance of contouring quality and integrity while minimizing patient CT simulation dose. Methods: The authors proposed a general prediction strategy that provides automatic optimal CT simulation protocol selection as a function of patient size and treatment planning task. The optimal protocol is the one that delivers the minimum dose required to provide a CT simulation scan that yields accurate contours. Accurate treatment plans depend on accurate contours in order to conform the dose to actual tumor and normal organ positions. An image quality index, defined to characterize how simulation scan quality affects contour delineation, was developed and used to benchmark the contouring accuracy and treatment plan quality within the predication strategy. A clinical workflow was developed to select the optimal CT simulation protocols incorporating patient size, target delineation, and radiation dose efficiency. An experimental study using an anthropomorphic pelvis phantom with added-bolus layers was used to demonstrate how the proposed prediction strategy could be implemented and how the optimal CT simulation protocols could be selected for prostate cancer patients based on patient size and treatment planning task. Clinical IMRT prostate treatment plans for seven CT scans with varied image quality indices were separately optimized and compared to verify the trace of target and organ dosimetry coverage. Results: Based on the phantom study, the optimal image quality index for accurate manual prostate contouring was 4.4. The optimal tube potentials for patient sizes of 38, 43, 48, 53, and 58 cm were 120, 140, 140, 140, and 140 kVp, respectively, and the corresponding minimum CTDIvol for achieving the optimal image quality index 4.4 were 9.8, 32.2, 100.9, 241.4, and 274.1 mGy, respectively. For patients with lateral sizes of 43–58 cm, 120-kVp scan protocols yielded up to 165% greater radiation dose relative to 140-kVp protocols, and 140-kVp protocols always yielded a greater image quality index compared to the same dose-level 120-kVp protocols. The trace of target and organ dosimetry coverage and the γ passing rates of seven IMRT dose distribution pairs indicated the feasibility of the proposed image quality index for the predication strategy. Conclusions: A general strategy to predict the optimal CT simulation protocols in a flexible and quantitative way was developed that takes into account patient size, treatment planning task, and radiation dose. The experimental study indicated that the optimal CT simulation protocol and the corresponding radiation dose varied significantly for different patient sizes, contouring accuracy, and radiation treatment planning tasks.

  3. Ultrasound-based guidance of intensity-modulated radiation therapy

    SciTech Connect

    Fung, Albert Y.C. . E-mail: afung@unmc.edu; Ayyangar, Komanduri M.; Djajaputra, David; Nehru, Ramasamy M.; Enke, Charles A.

    2006-04-01

    In ultrasound-guided intensity-modulated radiation therapy (IMRT) of prostate cancer, ultrasound imaging ascertains the anatomical position of patients during x-ray therapy delivery. The ultrasound transducers are made of piezoelectric ceramics. The same crystal is used for both ultrasound production and reception. Three-dimensional (3D) ultrasound devices capture and correlate series of 2-dimensional (2D) B-mode images. The transducers are often arranged in a convex array for focusing. Lower frequency reaches greater depth, but results in low resolution. For clear image, some gel is usually applied between the probe and the skin contact surface. For prostate positioning, axial and sagittal scans are performed, and the volume contours from computed tomography (CT) planning are superimposed on the ultrasound images obtained before radiation delivery at the linear accelerator. The planning volumes are then overlaid on the ultrasound images and adjusted until they match. The computer automatically deduces the offset necessary to move the patient so that the treatment area is in the correct location. The couch is translated as needed. The currently available commercial equipment can attain a positional accuracy of 1-2 mm. Commercial manufacturer designs differ in the detection of probe coordinates relative to the isocenter. Some use a position-sensing robotic arm, while others have infrared light-emitting diodes or pattern-recognition software with charge-couple-device cameras. Commissioning includes testing of image quality and positional accuracy. Ultrasound is mainly used in prostate positioning. Data for 7825 daily fractions of 234 prostate patients indicated average 3D inter-fractional displacement of about 7.8 mm. There was no perceivable trend of shift over time. Scatter plots showed slight prevalence toward superior-posterior directions. Uncertainties of ultrasound guidance included tissue inhomogeneities, speckle noise, probe pressure, and inter-observer variation. Some published studies detected improvement in treatment based on gastrointestinal toxicity and the reduction of prostate movement.

  4. Hypofractionated stereotactic radiation therapy in skull base meningiomas.

    PubMed

    Navarria, Pierina; Pessina, Federico; Cozzi, Luca; Clerici, Elena; Villa, Elisa; Ascolese, Anna Maria; De Rose, Fiorenza; Comito, Tiziana; Franzese, Ciro; D'Agostino, Giuseppe; Lobefalo, Francesca; Fogliata, Antonella; Reggiori, Giacomo; Fornari, Maurizio; Tomatis, Stefano; Bello, Lorenzo; Scorsetti, Marta

    2015-09-01

    To investigate the role of hypo-fractionated stereotactic radiation treatment (HSRT) in the management of skull base meningioma. Twenty-six patients were included in the study and treated with a dose of 30 Gy in 5 fractions with volumetric modulated arc therapy (RapidArc). Eighteen patients were symptomatic before treatment. Endpoints were local toxicity and relief from symptoms. Tumors were located in anterior skull base in 4/27 cases, in middle skull base in 12/27 and in posterior skull base in 11/27. HSRT was performed as first treatment in 17 (65 %) patients, in 9 (35 %) patients it followed a previous partial resection. Median follow up was 24.5 months (range 5-57 months). clinical remission of symptoms, complete or partial, was obtained in the vast majority of patients after treatment. Out of the 18 symptomatic patients, partial remission occurred in 9 (50 %) patients and complete remission in 9 (50 %). All asymptomatic patients retained their status after treatment. No severe neurologic toxicity grade III-IV was recorded. No increase of meningioma in the same site of treatment occurred; 16 (62 %) patients had stable disease and 9 (38 %) patients had tumor reduction. The mean tumor volume after treatment was 10.8 ± 17.8 cm(3) compared with 13.0 ± 19.1 cm(3) before treatment (p = 0.02). The mean actuarial OS was 54.4 ± 2.8 months. The 1- and 2-years OS was 92.9 ± 0.7 %. HSRT proved to be feasible for these patients not eligible to full surgery or to ablative radiation therapy. Local control and durability of results suggest for a routine application of this approach in properly selected cases. PMID:26040487

  5. Proton-minibeam radiation therapy: A proof of concept

    SciTech Connect

    Prezado, Y.; Fois, G. R.

    2013-03-15

    Purpose: This Monte Carlo simulation work aims at studying a new radiotherapy approach called proton-minibeam radiation therapy (pMBRT). The main objective of this proof of concept was the evaluation of the possible gain in tissue sparing, thanks to the spatial fractionation of the dose, which could be used to deposit higher and potentially curative doses in clinical cases where tissue tolerances are a limit for conventional methods. Methods: Monte Carlo simulations (GATE v.6) have been used as a method to calculate the ratio of the peak-to-valley doses (PVDR) for arrays of proton minibeams of 0.7 mm width and several center-to-center distances, at different depths in a water phantom. The beam penumbras were also evaluated as an important parameter for tissue sparing, for example, in the treatment of non-cancer diseases like epilepsy. Two proton energies were considered in this study: a clinically relevant energy (105 MeV) and a very high energy (1 GeV), to benefit from a reduced lateral scattering. For the latter case, an interlaced geometry was also evaluated. Results: Higher or similar PVDR than the ones obtained in x-rays minibeam radiation therapy were achieved in several pMBRT configurations. In addition, for the two energies studied, the beam penumbras are smaller than in the case of Gamma Knife radiosurgery. Conclusions: The high PVDR obtained for some configurations and the small penumbras in comparison with existing radiosurgery techniques, suggest a potential gain in healthy tissue sparing in this new technique. Biological studies are warranted to assess the effects of pMBRT on both normal and tumoral tissues.

  6. Dosimetrically Triggered Adaptive Intensity Modulated Radiation Therapy for Cervical Cancer

    SciTech Connect

    Lim, Karen; Stewart, James; Kelly, Valerie; Xie, Jason; Brock, Kristy K.; Moseley, Joanne; Cho, Young-Bin; Fyles, Anthony; Lundin, Anna; Rehbinder, Henrik; Löf, Johan; Jaffray, David A.; Milosevic, Michael

    2014-09-01

    Purpose: The widespread use of intensity modulated radiation therapy (IMRT) for cervical cancer has been limited by internal target and normal tissue motion. Such motion increases the risk of underdosing the target, especially as planning margins are reduced in an effort to reduce toxicity. This study explored 2 adaptive strategies to mitigate this risk and proposes a new, automated method that minimizes replanning workload. Methods and Materials: Thirty patients with cervical cancer participated in a prospective clinical study and underwent pretreatment and weekly magnetic resonance (MR) scans over a 5-week course of daily external beam radiation therapy. Target volumes and organs at risk (OARs) were contoured on each of the scans. Deformable image registration was used to model the accumulated dose (the real dose delivered to the target and OARs) for 2 adaptive replanning scenarios that assumed a very small PTV margin of only 3 mm to account for setup and internal interfractional motion: (1) a preprogrammed, anatomy-driven midtreatment replan (A-IMRT); and (2) a dosimetry-triggered replan driven by target dose accumulation over time (D-IMRT). Results: Across all 30 patients, clinically relevant target dose thresholds failed for 8 patients (27%) if 3-mm margins were used without replanning. A-IMRT failed in only 3 patients and also yielded an additional small reduction in OAR doses at the cost of 30 replans. D-IMRT assured adequate target coverage in all patients, with only 23 replans in 16 patients. Conclusions: A novel, dosimetry-triggered adaptive IMRT strategy for patients with cervical cancer can minimize the risk of target underdosing in the setting of very small margins and substantial interfractional motion while minimizing programmatic workload and cost.

  7. The nature of iron deposits differs between symptomatic and asymptomatic carotid atherosclerotic plaques

    SciTech Connect

    Kopriva, David; Kisheev, Anastasye; Meena, Deiter; Pelle, Shaneen; Karnitsky, Max; Lavoie, Andrea; Buttigieg, Josef; Hagemeyer, Christoph E.

    2015-11-25

    Iron within atherosclerotic plaque has been implicated as a catalyst of oxidative stress that causes progression of plaque, and plaque rupture. Iron is believed to accumulate within plaque by incorporation of erythrocytes following plaque rupture and hemorrhage. There is only indirect evidence to support this hypothesis. Plaque specimens were obtained from ten symptomatic and fifteen asymptomatic patients undergoing carotid endarterectomy at a single institution. Plaques were sectioned for study using synchrotron radiation induced X-ray fluorescence the study the distribution of zinc, calcium and iron. Histologic staining was carried out with Prussian Blue, and immunohistochemical staining was done to localize macrophages with CD68. Data were compared against patient clinical variables. Ten symptomatic (15 ± 10 days between index symptoms and surgery) and fifteen asymptomatic carotid plaques were studied. Zinc and calcium co-localized in mineralized areas of symptomatic and asymptomatic plaque. Iron was identified away from zinc and calcium in both symptomatic and asymptomatic plaques. Within the symptomatic plaques, iron was found within the thrombus associated with plaque rupture and hemorrhage. It did not stain with Prussian Blue, but was found in association with CD68 positive macrophages. In symptomatic plaques, the abundance of iron showed an association with the source patient’s LDL cholesterol (R2 = 0.39, Significance F = 0.05). Iron in asymptomatic plaque was present as hemosiderin/ferritin that stained positive with Prussian Blue, and was observed in association with CD68 positive macrophages. Iron in acutely symptomatic plaques is found within thrombus, in the presence of macrophages. Moreover, the abundance of iron in symptomatic plaques is associated with the source patient’s LDL cholesterol. Within asymptomatic plaques, iron is found in association with macrophages, as hemosiderin/ferritin.

  8. The nature of iron deposits differs between symptomatic and asymptomatic carotid atherosclerotic plaques

    DOE PAGESBeta

    Kopriva, David; Kisheev, Anastasye; Meena, Deiter; Pelle, Shaneen; Karnitsky, Max; Lavoie, Andrea; Buttigieg, Josef; Hagemeyer, Christoph E.

    2015-11-25

    Iron within atherosclerotic plaque has been implicated as a catalyst of oxidative stress that causes progression of plaque, and plaque rupture. Iron is believed to accumulate within plaque by incorporation of erythrocytes following plaque rupture and hemorrhage. There is only indirect evidence to support this hypothesis. Plaque specimens were obtained from ten symptomatic and fifteen asymptomatic patients undergoing carotid endarterectomy at a single institution. Plaques were sectioned for study using synchrotron radiation induced X-ray fluorescence the study the distribution of zinc, calcium and iron. Histologic staining was carried out with Prussian Blue, and immunohistochemical staining was done to localize macrophagesmore » with CD68. Data were compared against patient clinical variables. Ten symptomatic (15 ± 10 days between index symptoms and surgery) and fifteen asymptomatic carotid plaques were studied. Zinc and calcium co-localized in mineralized areas of symptomatic and asymptomatic plaque. Iron was identified away from zinc and calcium in both symptomatic and asymptomatic plaques. Within the symptomatic plaques, iron was found within the thrombus associated with plaque rupture and hemorrhage. It did not stain with Prussian Blue, but was found in association with CD68 positive macrophages. In symptomatic plaques, the abundance of iron showed an association with the source patient’s LDL cholesterol (R2 = 0.39, Significance F = 0.05). Iron in asymptomatic plaque was present as hemosiderin/ferritin that stained positive with Prussian Blue, and was observed in association with CD68 positive macrophages. Iron in acutely symptomatic plaques is found within thrombus, in the presence of macrophages. Moreover, the abundance of iron in symptomatic plaques is associated with the source patient’s LDL cholesterol. Within asymptomatic plaques, iron is found in association with macrophages, as hemosiderin/ferritin.« less

  9. The Nature of Iron Deposits Differs between Symptomatic and Asymptomatic Carotid Atherosclerotic Plaques

    PubMed Central

    Kopriva, David; Kisheev, Anastasye; Meena, Deiter; Pelle, Shaneen; Karnitsky, Max; Lavoie, Andrea; Buttigieg, Josef

    2015-01-01

    Iron within atherosclerotic plaque has been implicated as a catalyst of oxidative stress that causes progression of plaque, and plaque rupture. Iron is believed to accumulate within plaque by incorporation of erythrocytes following plaque rupture and hemorrhage. There is only indirect evidence to support this hypothesis. Plaque specimens were obtained from ten symptomatic and fifteen asymptomatic patients undergoing carotid endarterectomy at a single institution. Plaques were sectioned for study using synchrotron radiation induced X-ray fluorescence the study the distribution of zinc, calcium and iron. Histologic staining was carried out with Prussian Blue, and immunohistochemical staining was done to localize macrophages with CD68. Data were compared against patient clinical variables. Ten symptomatic (15 ± 10 days between index symptoms and surgery) and fifteen asymptomatic carotid plaques were studied. Zinc and calcium co-localized in mineralized areas of symptomatic and asymptomatic plaque. Iron was identified away from zinc and calcium in both symptomatic and asymptomatic plaques. Within the symptomatic plaques, iron was found within the thrombus associated with plaque rupture and hemorrhage. It did not stain with Prussian Blue, but was found in association with CD68 positive macrophages. In symptomatic plaques, the abundance of iron showed an association with the source patient’s LDL cholesterol (R2 = 0.39, Significance F = 0.05). Iron in asymptomatic plaque was present as hemosiderin/ferritin that stained positive with Prussian Blue, and was observed in association with CD68 positive macrophages. Iron in acutely symptomatic plaques is found within thrombus, in the presence of macrophages. The abundance of iron in symptomatic plaques is associated with the source patient’s LDL cholesterol. Within asymptomatic plaques, iron is found in association with macrophages, as hemosiderin/ferritin. PMID:26606178

  10. Commissioning and implementation of an implantable dosimeter for radiation therapy.

    PubMed

    Buzurovic, Ivan; Showalter, Timothy N; Studenski, Matthew T; Den, Robert B; Dicker, Adam P; Cao, Junsheng; Xiao, Ying; Yu, Yan; Harrison, Amy

    2013-01-01

    In this article we describe commissioning and implementation procedures for the Dose Verification System (DVS) with permanently implanted in vivo wireless, telemetric radiation dosimeters for absolute dose measurements. The dosimeter uses a semiconductor device called a metal-oxide semiconductor field-effect transistor (MOSFET) to measure radiation dose. A MOSFET is a transistor that is generally used for amplifying or switching electronic signals. The implantable dosimeter was implemented with the goal of verifying the dose delivered to radiation therapy patients. For the purpose of acceptance testing, commissioning, and clinical implementation and to evaluate characteristics of the dosimeter, the following tests were performed: 1) temperature dependence, 2) reproducibility,3) field size dependence, 4) postirradiation signal drift, 5) dependence on average dose rate, 6) linearity test, 7) angular dependence (different gantry angle position), 8) angular dependence (different DVS angle position), 9) dose rate dependence,10) irradiation depth dependence, 11) effect of cone-beam exposure to the dosimeter, and 12) multiple reading effect. The dosimeter is not currently calibrated for use in the kV range; nonetheless, the effect of the cone-beam procedure on the MOSFET dosimeter was investigated. Phantom studies were performed in both air and water using an Elekta Synergy S Beam-Modulator linear accelerator. Commissioning and clinical implementation for prostate cancer patients receiving external-beam radiation therapy were performed in compliance with the general recommendations given for in vivo dosimetry devices. The reproducibility test in water at human body temperature (37°C) showed a 1.4% absolute difference, with a standard deviation of 5.72 cGy (i.e., SD = 2.9%). The constancy test shows that the average readings at room temperature were 3% lower compared to the readings at human body temperature, with a SD = 2%. Measurements were not dependent upon field size. Due to postirradiation signal drift, the following corrections are suggested: -2.8%, -2%, 0.5%, and 2.5% for the readings taken after 0.5, 1, 5, or 10 min, respectively. Different gantry angles did not influence the readings. The maximum error was less than 1% with a maximum SD = 3.61 cGy (1.8%) for the gantry angle of 45°. However, readings are dependent on the dosimeter orientation. The average dose reading was 7.89 cGy (SD = 1.46 cGy) when CBCT imaging was used for the pelvis protocol, and when postirradiation measurement was taken at 2.5 min (expected 2-3 cGy). The clinical implementation of the implantable MOSFET dosimeters for prostate cancer radiation therapy is described. Measurements performed for commissioning show that the dosimeter, if used within specifications, provides sufficient accuracy for its intended use in clinical procedures. The postradiation signal drift, temperature dependence, variation of reproducibility, and rotational isotropy could be encountered if the dosimeter is used outside the manufacturer's specifications. The dosimeter can be used as a tool for quantifying dose at depth, as well as to evaluate adherence between planned doses and the delivered doses. Currently, the system is clinically implemented with ± 7% tolerance. PMID:23470929

  11. Automated fiducial marker planning for thoracic stereotactic body radiation therapy

    NASA Astrophysics Data System (ADS)

    Gibbs, Jason D.; Rai, Lav; Wibowo, Henky; Tsalyuk, Serge; Anderson, Eric D.

    2012-02-01

    Stereotactic body-radiation therapy (SBRT) has gained acceptance in treating lung cancer. Localization of a thoracic lesion is challenging as tumors can move significantly with breathing. Some SBRT systems compensate for tumor motion with the intrafraction tracking of targets by two stereo fluoroscopy cameras. However, many lung tumors lack a fluoroscopic signature and cannot be directly tracked. Small radiopaque fiducial markers, acting as fluoroscopically visible surrogates, are instead implanted nearby. The spacing and configuration of the fiducial markers is important to the success of the therapy as SBRT systems impose constraints on the geometry of a fiducial-marker constellation. It is difficult even for experienced physicians mentally assess the validity of a constellation a priori. To address this challenge, we present the first automated planning system for bronchoscopic fiducial-marker placement. Fiducial-marker planning is posed as a constrained combinatoric optimization problem. Constraints include requiring access from a navigable airway, having sufficient separation in the fluoroscopic imaging planes to resolve each individual marker, and avoidance of major blood vessels. Automated fiducial-marker planning takes approximately fifteen seconds, fitting within the clinical workflow. The resulting locations are integrated into a virtual bronchoscopic planning system, which provides guidance to each location during the implantation procedure. To date, we have retrospectively planned over 50 targets for treatment, and have implanted markers according to the automated plan in one patient who then underwent SBRT treatment. To our knowledge, this approach is the first to address automated bronchoscopic fiducialmarker planning for SBRT.

  12. On bolus for megavoltage photon and electron radiation therapy

    SciTech Connect

    Vyas, Vedang; Palmer, Lisa; Mudge, Ray; Jiang, Runqing; Fleck, Andre; Schaly, Bryan; Osei, Ernest; Charland, Paule

    2013-10-01

    Frequently, in radiation therapy one must treat superficial lesions on cancer patients; these are at or adjacent to the skin. Megavoltage photon radiotherapy penetrates through the skin to irradiate deep-seated tumors, with skin-sparing property. Hence, to treat superficial lesions, one must use a layer of scattering material to feign as the skin surface. Although megavoltage electron beams are used for superficial treatments, one occasionally needs to enhance the dose near the surface. Such is the function of a “bolus,” a natural or synthetically developed material that acts as a layer of tissue to provide a more effective treatment to the superficial lesions. Other uses of boluses are to correct for varying surface contours and to add scattering material around the patient's surface. Materials used as bolus vary from simple water to metal and include various mixtures and compounds. Even with the modernization of the technology for external-beam therapy and the emergence of various commercial boluses, the preparation and utilization of a bolus in clinical radiotherapy remains an art. Considering the varying experiences and practices, this paper briefly summarizes available boluses that have been proposed and are employed in clinical radiotherapy. Although this review is not exhaustive, it provides some initial guidance and answers questions that may arise in clinical practice.

  13. The retina dose-area histogram: a metric for quantitatively comparing rival eye plaque treatment options

    PubMed Central

    2013-01-01

    Purpose Episcleral plaques have a history of over a half century in the delivery of radiation therapy to intraocular tumors such as choroidal melanoma. Although the tumor control rate is high, vision-impairing complications subsequent to treatment remain an issue. Notable, late complications are radiation retinopathy and maculopathy. The obvious way to reduce the risk of radiation damage to the retina is to conform the prescribed isodose surface to the tumor base and to reduce the dose delivered to the surrounding healthy retina, especially the macula. Using a fusion of fundus photography, ultrasound and CT images, tumor size, shape and location within the eye can be accurately simulated as part of the radiation planning process. In this work an adaptation of the dose-volume histogram (DVH), the retina dose-area histogram (RDAH) is introduced as a metric to help compare rival plaque designs and conformal treatment planning options with the goal of reducing radiation retinopathy. Material and methods The RDAH is calculated by transforming a digitized fundus-photo collage of the tumor into a rasterized polar map of the retinal surface known as a retinal diagram (RD). The perimeter of the tumor base is digitized on the RD and its area computed. Area and radiation dose are calculated for every pixel in the RD. Results The areal resolution of the RDAH is a function of the pixel resolution of the raster image used to display the RD and the number of polygon edges used to digitize the perimeter of the tumor base. A practical demonstration is presented. Conclusions The RDAH provides a quantitative metric by which episcleral plaque treatment plan options may be evaluated and compared in order to confirm adequate dosimetric coverage of the tumor and margin, and to help minimize dose to the macula and retina. PMID:23634152

  14. IMRT (intensity modulated radiation therapy): progress in technology and reimbursement.

    PubMed

    Young, R; Snyder, B

    2001-01-01

    For a new treatment technology to become widely accepted in today's healthcare environment, the technology must not only be effective but also financially viable. Intensity modulated radiation therapy (IMRT), a technology that enables radiation oncologists to precisely target and attack cancerous tumors with higher doses of radiation using strategically positioned beams while minimizing collateral damage to healthy cells, now meets both criteria. With IMRT, radiation oncologists for the first time have obtained the ability to divide the treatment field covered by each beam angle into hundreds of segments as small as 2.5 mm by 5 mm. Using the adjustable leaves of an MLC to shape the beam and by controlling exposure times, physicians can deliver a different dose to each segment and therefore modulate dose intensity across the entire treatment field. Development of optimal IMRT plans using conventional manual treatment planning methods would take days. To be clinically practical, IMRT required the development of "inverse treatment planning" software. With this software, a radiation oncologist can prescribe the ideal radiation dose for a specific tumor as well as maximum dose limits for surrounding healthy tissue. These numbers are entered into the treatment planning program which then calculates the optimal delivery approach that will best fit the oncologist's requirements. The radiation oncologist then reviews and approves the proposed treatment plan before it is initiated. The most recent advance in IMRT technology offers a "dynamic" mode or "sliding window" technique. In this more rapid delivery method, the beam remains on while the leaves of the collimator continually re-shape and move the beam aperture over the planned treatment area. This creates a moving beam that saturates the tumor volume with the desired radiation dose while leaving the surrounding healthy tissue in a protective shadow created by the leaves of the collimator. In the dynamic mode, an IMRT treatment session generally can be initiated and completed within the traditional 15-minute appointment window for radiation oncology clinics. In addition to being comforting for the patient, this rapid treatment delivery mode satisfies a key financial issue for hospitals and clinics by giving them the ability to handle high patient loads and achieve a more rapid return on their investment in an IMRT system. New IMRT reimbursement codes have been issued under the pass-through provisions of Medicare's Outpatient Prospective Payment System (OPPS), which authorize special or increased reimbursement levels for promising new developments in healthcare technology that previous reimbursement procedures did not address. These pass-through payments are generally applicable for defined periods during a promising new technology's early stage of adoption. In the case of codes G0174 and G0178, the effective period has been left open-ended. While the CMS adoption of these new IMRT reimbursement codes certainly paves the economic road for the diffusion of this technology by flattening out some of the economic obstacles, there are still bumps to overcome. The most obvious one is the investment in hardware and software that may be required. However, the added demands on staff and the cost of training cannot be ignored. IMRT is a treatment process involving FDA-approved medical devices, offering the hope of improved treatment outcomes with fewer complications for patients and higher reimbursement rates for hospital providers. By the end of the year 2001, there will probably be more than 75 hospitals with IMRT capabilities in place. PMID:11793560

  15. Stent deployment for peripheral venous stenosis as a result of radiation therapy.

    PubMed

    Franklin, Wayne J; Strickman, Neil E; Hall, Robert J

    2003-05-01

    Arterial occlusive disease is a well-known complication of radiation therapy, but venous thrombosis and occlusion after radiotherapy may also occur. We report the use of an endovascular stent to treat a patient who developed peripheral venous stenosis 4 years after radiation therapy for malignant melanoma. PMID:12720242

  16. Calcified basal ganglionic mass 12 years after radiation therapy for medulloblastoma

    SciTech Connect

    Lichtor, T.; Wollmann, R.L.; Brown, F.D.

    1984-04-01

    A patient treated 12 years previously with an operation and radiation therapy for a medulloblastoma developed weakness of the left hand and perivascular calcification involving the right internal capsule and caudate nucleus. These findings are considered possible long-term complications of the radiation therapy.

  17. Aortic Arch Plaques and Risk of Recurrent Stroke and Death

    PubMed Central

    Di Tullio, Marco R.; Russo, Cesare; Jin, Zhezhen; Sacco, Ralph L.; Mohr, J.P.; Homma, Shunichi

    2010-01-01

    Background Aortic arch plaques are a risk factor for ischemic stroke. Although the stroke mechanism is conceivably thromboembolic, no randomized studies have evaluated the efficacy of antithrombotic therapies in preventing recurrent events. Methods and Results The relationship between arch plaques and recurrent events was studied in 516 patients with ischemic stroke, double–blindly randomized to treatment with warfarin or aspirin as part of the Patent Foramen Ovale in Cryptogenic Stroke Study (PICSS), based on the Warfarin-Aspirin Recurrent Stroke Study (WARSS). Plaque thickness and morphology was evaluated by transesophageal echocardiography. End-points were recurrent ischemic stroke or death over a 2-year follow-up. Large plaques (≥4mm) were present in 19.6% of patients, large complex plaques (those with ulcerations or mobile components) in 8.5 %. During follow-up, large plaques were associated with a significantly increased risk of events (adjusted Hazard Ratio 2.12, 95% Confidence Interval 1.04-4.32), especially those with complex morphology (HR 2.55, CI 1.10-5.89). The risk was highest among cryptogenic stroke patients, both for large plaques (HR 6.42, CI 1.62-25.46) and large-complex plaques (HR 9.50, CI 1.92-47.10). Event rates were similar in the warfarin and aspirin groups in the overall study population (16.4% vs. 15.8%; p=0.43). Conclusions In patients with stroke, and especially cryptogenic stroke, large aortic plaques remain associated with an increased risk of recurrent stroke and death at two years despite treatment with warfarin or aspirin. Complex plaque morphology confers a slight additional increase in risk. PMID:19380621

  18. La pelade par plaques

    PubMed Central

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre les schémas thérapeutiques et les résultats des traitements pour la pelade par plaques, de même que les aider à identifier les patients pour qui une demande de consultation en dermatologie pourrait s’imposer. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant le traitement de la pelade par plaques. Message principal La pelade par plaques est une forme auto-immune de perte pileuse qui touche à la fois les enfants et les adultes. Même s’il n’y a pas de mortalité associée à la maladie, la morbidité découlant des effets psychologiques de la perte des cheveux peut être dévastatrice. Lorsque la pelade par plaques et le sous-type de la maladie sont identifiés, un schéma thérapeutique approprié peut être amorcé pour aider à arrêter la chute des cheveux et possiblement faire commencer la repousse. Les traitements de première intention sont la triamcinolone intralésionnelle avec des corticostéroïdes topiques ou du minoxidil ou les 2. Les médecins de famille peuvent prescrire ces traitements en toute sécurité et amorcer ces thérapies. Les cas plus avancés ou réfractaires pourraient avoir besoin de diphénylcyclopropénone topique ou d’anthraline topique. On peut traiter la perte de cils avec des analogues de la prostaglandine. Les personnes ayant subi une perte de cheveux abondante peuvent recourir à des options de camouflage ou à des prothèses capillaires. Il est important de surveiller les troubles psychiatriques en raison des effets psychologiques profonds de la perte de cheveux. Conclusion Les médecins de famille verront de nombreux patients qui perdent leurs cheveux. La reconnaissance de la pelade par plaques et la compréhension du processus pathologique sous-jacent permettent d’amorcer un schéma thérapeutique approprié. Les cas plus graves ou réfractaires doivent être identifiés pour qu’une demande de consultation en dermatologie soit demandée au besoin.

  19. La pelade par plaques

    PubMed Central

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre l’épidémiologie, la pathogenèse, l’histologie et l’approche clinique au diagnostic de la pelade par plaques. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant la pathogenèse, le diagnostic et le pronostic de la pelade par plaques. Message principal La pelade par plaques est une forme de perte pileuse auto-immune dont la prévalence durant une vie est d’environ 2 %. Des antécédents personnels ou familiaux de troubles auto-immuns concomitants, comme le vitiligo ou une maladie de la thyroïde, peuvent être observés dans un petit sous-groupe de patients. Le diagnostic peut souvent être posé de manière clinique en se fondant sur la perte de cheveux non cicatricielle et circulaire caractéristique, accompagnée de cheveux en « point d’exclamation » en périphérie chez ceux dont le problème en est aux premiers stades. Le diagnostic des cas plus complexes ou des présentations inhabituelles peut être facilité par une biopsie et un examen histologique. Le pronostic varie largement et de mauvais résultats sont associés à une apparition à un âge précoce, une perte importante, la variante ophiasis, des changements aux ongles, des antécédents familiaux ou des troubles auto-immuns concomitants. Conclusion La pelade par plaques est une forme auto-immune de perte de cheveux périodiquement observée en soins primaires. Les médecins de famille sont bien placés pour identifier la pelade par plaques, déterminer la gravité de la maladie et poser le diagnostic différentiel approprié. De plus, ils sont en mesure de renseigner leurs patients à propos de l’évolution clinique de la maladie ainsi que du pronostic général selon le sous-type de patients.

  20. Academic Career Selection and Retention in Radiation Oncology: The Joint Center for Radiation Therapy Experience

    SciTech Connect

    Balboni, Tracy A. . E-mail: tbalboni@partners.org; Chen, M.-H.; Harris, Jay R.; Recht, Abram; Stevenson, Mary Ann; D'Amico, Anthony V.

    2007-05-01

    Purpose: The United States healthcare system has witnessed declining reimbursement and increasing documentation requirements for longer than 10 years. These have decreased the time available to academic faculty for teaching and mentorship. The impact of these changes on the career choices of residents is unknown. The purpose of this report was to determine whether changes have occurred during the past decade in the proportion of radiation oncology trainees from a single institution entering and staying in academic medicine. Methods and Materials: We performed a review of the resident employment experience of Harvard Joint Center for Radiation Therapy residents graduating during 13 recent consecutive years (n = 48 residents). The outcomes analyzed were the initial selection of an academic vs. nonacademic career and career changes during the first 3 years after graduation. Results: Of the 48 residents, 65% pursued an academic career immediately after graduation, and 44% remained in academics at the last follow-up, after a median of 6 years. A later graduation year was associated with a decrease in the proportion of graduates immediately entering academic medicine (odds ratio, 0.78; 95% confidence interval, 0.65-0.94). However, the retention rate at 3 years of those who did immediately enter academics increased with a later graduation year (p = 0.03). Conclusion: During a period marked by notable changes in the academic healthcare environment, the proportion of graduating Harvard Joint Center for Radiation Therapy residents pursuing academic careers has been declining; however, despite this decline, the retention rates in academia have increased.

  1. Radiation therapy of conjunctival and orbital lymphoid tumors

    SciTech Connect

    Jereb, B.; Lee, H.; Jakobiec, F.A.; Kutcher, J.

    1984-07-01

    Lymphoid tumors of the conjuctiva and orbit are rare and remain localized in the majority of cases. Sometimes it is not possible either clinically or histologically to differentiate between a non-Hodgkin's lymphoma (NHL) and benign lymphoid hyperplasia. A series of 24 patients is reported. Nineteen were classified as having malignant NHL and 5 benign hyperplasia; 1 of these 5 later developed metastases, however. All patients had systemic work-up: 18 had Stage I, 1 had Stage II, and 5 had Stage IV disease. All patients received local radiation therapy with doses of 2400 to 2750 rad in 2-3 weeks for lesions of the eyelid and conjunctiva, and between 3000 and 3750 rad in 3-4 weeks for retrobulbar lesions. A method of shielding the lens with a lead block mounted on a low vac lens is described, and the dose distribution within the eye and orbit is presented. Patients who were treated with doses higher than 3000 rad experienced conjunctivitis and skin erythema that resolved completely. No other effects of radiation on normal structures of the ocular adnexa were observed in the 20 patients who are alive and without signs of tumor 10-46 months with a median follow-up time of 22 months.

  2. A generalized pencil beam algorithm for optimization of radiation therapy.

    PubMed

    Gustafsson, A; Lind, B K; Brahme, A

    1994-03-01

    An iterative pencil beam algorithm for optimization of multidimensional radiation therapy dose plans has been developed. The algorithm allows the use of both physical and radiobiological treatment objective functions and allows arbitrary sampling such as straight Cartesian grids with linear or nonlinear sampling functions or random sampling. The algorithm can account for and optimally combine almost all the degrees of freedom at an advanced radiotherapy clinic, such as different beam modalities and spectra, beam directions, beam fluence distributions, and time-dose fractionations. The algorithm allows for external charged and neutral beams as well as intracavitary and interstitial sources to be optimally combined. A quantity termed the generalized fluence vector is introduced, combining fluences and energy fluences from external beams as well as the radiation source densities of intracavitary and interstitial sources or external source distributions. The positivity constraint on the generalized fluence can therefore be applied directly during the optimization procedure. The convergence properties and the required iteration time of the algorithm are discussed. Several examples with combinations of photon and electron beams of different energies and directions of incidence are presented. The optimization has been made with the treatment objective to maximize the probability of achieving tumor control without causing severe complications in healthy normal tissues. PMID:8208209

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

    SciTech Connect

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

    2009-12-01

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

  4. Direct aperture optimization for online adaptive radiation therapy

    SciTech Connect

    Mestrovic, Ante; Milette, Marie-Pierre; Nichol, Alan; Clark, Brenda G.; Otto, Karl

    2007-05-15

    This paper is the first investigation of using direct aperture optimization (DAO) for online adaptive radiation therapy (ART). A geometrical model representing the anatomy of a typical prostate case was created. To simulate interfractional deformations, four different anatomical deformations were created by systematically deforming the original anatomy by various amounts (0.25, 0.50, 0.75, and 1.00 cm). We describe a series of techniques where the original treatment plan was adapted in order to correct for the deterioration of dose distribution quality caused by the anatomical deformations. We found that the average time needed to adapt the original plan to arrive at a clinically acceptable plan is roughly half of the time needed for a complete plan regeneration, for all four anatomical deformations. Furthermore, through modification of the DAO algorithm the optimization search space was reduced and the plan adaptation was significantly accelerated. For the first anatomical deformation (0.25 cm), the plan adaptation was six times more efficient than the complete plan regeneration. For the 0.50 and 0.75 cm deformations, the optimization efficiency was increased by a factor of roughly 3 compared to the complete plan regeneration. However, for the anatomical deformation of 1.00 cm, the reduction of the optimization search space during plan adaptation did not result in any efficiency improvement over the original (nonmodified) plan adaptation. The anatomical deformation of 1.00 cm demonstrates the limit of this approach. We propose an innovative approach to online ART in which the plan adaptation and radiation delivery are merged together and performed concurrently--adaptive radiation delivery (ARD). A fundamental advantage of ARD is the fact that radiation delivery can start almost immediately after image acquisition and evaluation. Most of the original plan adaptation is done during the radiation delivery, so the time spent adapting the original plan does not increase the overall time the patient has to spend on the treatment couch. As a consequence, the effective time allotted for plan adaptation is drastically reduced. For the 0.25, 0.5, and 0.75 cm anatomical deformations, the treatment time was increased by only 2, 4, and 6 s, respectively, as compared to no plan adaptation. For the anatomical deformation of 1.0 cm the time increase was substantially larger. The anatomical deformation of 1.0 cm represents an extreme case, which is rarely observed for the prostate, and again demonstrates the limit of this approach. ARD shows great potential for an online adaptive method with minimal extension of treatment time.

  5. Radiation therapy for the palliation of multiple myeloma

    SciTech Connect

    Leigh, B.R.; Kurtts, T.A.; Mack, C.F.; Matzner, M.B.; Shimm, D.S. )

    1993-04-02

    This study reviews the experience at the University of Arizona in an effort to define the minimum effective radiation dose for durable pain relief in the majority of patients with symptomatic multiple myeloma. The records of 101 patients with multiple myeloma irradiated for palliation at the University of Arizona between 1975 and 1990 were reviewed. Three hundred sixteen sites were treated. Ten sites were asymptomatic, including six hemibody fields with advanced disease unresponsive to chemotherapy and four local fields with impending pathological fractures. Three hundred six evaluable symptomatic sites remained. The most common symptom was bone pain. Other symptoms included neurological impairment with a palpable mass. Total tumor dose ranged from 3.0 to 60 Gy, with a mean of 25 Gy. Symptom relief was obtained in 297 of 306 evaluable symptomatic sites (97%). Complete relief of symptoms was obtained in 26% and partial relief in 71%. Symptom relief was obtained in 92% of sites receiving a total dose less than 10 Gy (n = 13) and 98% of sites receiving 10 Gy or more (n = 293). No dose-response could be demonstrated. The likelihood of symptom relief was not influenced by the location of the lesion or the use of concurrent chemotherapy. Of the 297 responding sites, 6% (n = 19) relapsed after a median symptom-free interval of 16 months. Neither the probability of relapse nor the time to relapse was related to the radiation dose. Retreatment of relapsing sites provided effective palliation in all cases. Radiation therapy is effective in palliating local symptoms in multiple myeloma. A total dose of 10 Gy should provide durable symptom relief in the majority of patients. 16 refs., 3 figs., 4 tabs.

  6. Stroke-like Migraine Attacks after Radiation Therapy Syndrome

    PubMed Central

    Zheng, Qian; Yang, Li; Tan, Li-Ming; Qin, Li-Xia; Wang, Chun-Yu; Zhang, Hai-Nan

    2015-01-01

    Objective: To summarize the clinical presentation, pathogenesis, neuroimaging, treatment, and outcome of stroke-like migraine attacks after radiation therapy (SMART) syndrome, and to propose diagnostic criteria for this disorder. Data Sources: We searched the PubMed database for articles in English published from 1995 to 2015 using the terms of “stroke-like AND migraine AND radiation.” Reference lists of the identified articles and reviews were used to retrieve additional articles. Study Selection: Data and articles related to late-onset effects of cerebral radiation were selected and reviewed. Results: SMART is a rare condition that involves complex migraines with focal neurologic deficits following cranial irradiation for central nervous system malignancies. The recovery, which ranges from hours to days to weeks, can be partial or complete. We propose the following diagnostic criteria for SMART: (1) Remote history of therapeutic external beam cranial irradiation for malignancy; (2) prolonged, reversible clinical manifestations mostly years after irradiation, which may include migraine, seizures, hemiparesis, hemisensory deficits, visuospatial defect, aphasia, confusion and so on; (3) reversible, transient, unilateral cortical gadolinium enhancement correlative abnormal T2 and fluid-attenuated inversion recovery signal of the affected cerebral region; (4) eventual complete or partial recovery, the length of duration of recovery ranging from hours to days to weeks; (5) no evidence of residual or recurrent tumor; (6) not attributable to another disease. To date, no specific treatment has been identified for this syndrome. Conclusions: SMART is an extremely rare delayed complication of brain irradiation. However, improvements in cancer survival rates have resulted in a rise in its frequency. Hence, awareness and recognition of the syndrome is important to make a rapid diagnosis and avoid aggressive interventions such as brain biopsy and cerebral angiography. PMID:26228225

  7. Assessment of secondary radiation and radiation protection in laser-driven proton therapy.

    PubMed

    Faby, Sebastian; Wilkens, Jan J

    2015-06-01

    This work is a feasibility study of a radiation treatment unit with laser-driven protons based on a state-of-the-art energy selection system employing four dipole magnets in a compact shielded beamline. The secondary radiation emitted from the beamline and its energy selection system and the resulting effective dose to the patient are assessed. Further, it is evaluated whether or not such a compact system could be operated in a conventional treatment vault for clinical linear accelerators under the constraint of not exceeding the effective dose limit of 1 mSv per year to the general public outside the treatment room. The Monte Carlo code Geant4 is employed to simulate the secondary radiation generated while irradiating a hypothetical tumor. The secondary radiation inevitably generated inside the patient is taken into account as well, serving as a lower limit. The results show that the secondary radiation emanating from the shielded compact therapy system would pose a serious secondary dose contamination to the patient. This is due to the broad energy spectrum and in particular the angular distribution of the laser-driven protons, which make the investigated beamline together with the employed energy selection system quite inefficient. The secondary radiation also cannot be sufficiently absorbed in a conventional linear accelerator treatment vault to enable a clinical operation. A promising result, however, is the fact that the secondary radiation generated in the patient alone could be very well shielded by a regular treatment vault, allowing the application of more than 100 fractions of 2 Gy per day with protons. It is thus theoretically possible to treat patients with protons in such treatment vaults. Nevertheless, the results show that there is a clear need for alternative more efficient energy selection solutions for laser-driven protons. PMID:25267383

  8. The efficacy of sucralfate suspension in the prevention of oral mucositis due to radiation therapy

    SciTech Connect

    Epstein, J.B.; Wong, F.L.W. )

    1994-02-01

    The purpose of this study was to assess the value of sucralfate suspension in prevention of oral mucositis and for reduction of oral pain in patients who develop mucositis during radiation therapy. The study was a double-blind, placebo-controlled, randomized prospective trial of a sucralfate suspension in the prevention and management of oral mucositis during radiation therapy. Oral mucositis was assessed using a quantitative scale and symptoms were assessed using visual analogue scales. The statistical model was developed to detect a 40% reduction in mucositis. No statistically significant reduction in mucositis was seen. Early during radiation therapy less oral pain was reported in the sucralfate group, but as treatment progressed all patients experienced pain. Patients in the sucralfate group were prescribed topical and systemic analgesics later in the course of radiation therapy. Prophylactic oral rinsing with sucralfate did not prevent oral ulcerative mucositis. Sucralfate may reduce the experience of pain during radiation therapy. 32 refs., 3 tabs.

  9. Patient Specification Quality Assurance for Glioblastoma Multiforme Brain Tumors Treated with Intensity Modulated Radiation Therapy

    PubMed Central

    Al-Mohammed, H. I.

    2011-01-01

    The aim of this study was to evaluate the significance of performing patient specification quality assurance for patients diagnosed with glioblastoma multiforme treated with intensity modulated radiation therapy. The study evaluated ten intensity modulated radiation therapy treatment plans using 10 MV beams, a total dose of 60 Gy (2 Gy/fraction, five fractions a week for a total of six weeks treatment). For the quality assurance protocol we used a two-dimensional ionization-chamber array (2D-ARRAY). The results showed a very good agreement between the measured dose and the pretreatment planned dose. All the plans passed >95% gamma criterion with pixels within 5% dose difference and 3 mm distance to agreement. We concluded that using the 2D-ARRAY ion chamber for intensity modulated radiation therapy is an important step for intensity modulated radiation therapy treatment plans, and this study has shown that our treatment planning for intensity modulated radiation therapy is accurately done. PMID:21850196

  10. [Two Cases of Bleeding Advanced Gastric Cancer Treated with Palliative Radiation Therapy].

    PubMed

    Shimizu, Katsushu; Kimura, Yutaka; Hamakawa, Takuya; Mikami, Jota; Makari, Yoichi; Kawase, Tomono; Hoshino, Hiromitsu; Nakata, Ken; Yamamura, Jun; Kamigaki, Shunji; Ikeda, Naoki; Yamamoto, Tameyoshi; Tsujie, Masaki; Ikeda, Hiroshi; Ohzato, Hiroki

    2015-11-01

    Case 1: A man in his 70's was being treated with chemotherapy for unresectable advanced gastric cancer. Blood transfusion, endoscopic intervention including argon plasma coagulation, and transcatheter arterial embolization (TAE) were all used to treat repeated tumor bleeding causing anemia, but controlling the bleeding was difficult. In order to control the hemorrhage, radiation therapy of 31 Gy/10 Fr to the cancer was administered. After receiving radiation therapy, the anemia stopped. Case 2: A man in his 70's considered an operation for advanced gastric cancer, but his cardiac performance was poor and it was impossible to perform an operation. We conducted radiation therapy of 39 Gy/13 Fr for the purpose of preventing bleeding from gastric cancer. After receiving radiation therapy, the anemia stopped. We believe that radiation therapy is effective to stop bleeding from gastric cancer. PMID:26805144

  11. A comprehensive dosimetric study of pancreatic cancer treatment using three-dimensional conformal radiation therapy (3DCRT), intensity-modulated radiation therapy (IMRT), volumetric-modulated radiation therapy (VMAT), and passive-scattering and modulated-scanning proton therapy (PT)

    SciTech Connect

    Ding, Xuanfeng; Dionisi, Francesco; Tang, Shikui; Ingram, Mark; Hung, Chun-Yu; Prionas, Evangelos; Lichtenwalner, Phil; Butterwick, Ian; Zhai, Huifang; Yin, Lingshu; Lin, Haibo; Kassaee, Alireza; Avery, Stephen

    2014-07-01

    With traditional photon therapy to treat large postoperative pancreatic target volume, it often leads to poor tolerance of the therapy delivered and may contribute to interrupted treatment course. This study was performed to evaluate the potential advantage of using passive-scattering (PS) and modulated-scanning (MS) proton therapy (PT) to reduce normal tissue exposure in postoperative pancreatic cancer treatment. A total of 11 patients with postoperative pancreatic cancer who had been previously treated with PS PT in University of Pennsylvania Roberts Proton Therapy Center from 2010 to 2013 were identified. The clinical target volume (CTV) includes the pancreatic tumor bed as well as the adjacent high-risk nodal areas. Internal (iCTV) was generated from 4-dimensional (4D) computed tomography (CT), taking into account target motion from breathing cycle. Three-field and 4-field 3D conformal radiation therapy (3DCRT), 5-field intensity-modulated radiation therapy, 2-arc volumetric-modulated radiation therapy, and 2-field PS and MS PT were created on the patients’ average CT. All the plans delivered 50.4 Gy to the planning target volume (PTV). Overall, 98% of PTV was covered by 95% of the prescription dose and 99% of iCTV received 98% prescription dose. The results show that all the proton plans offer significant lower doses to the left kidney (mean and V{sub 18} {sub Gy}), stomach (mean and V{sub 20} {sub Gy}), and cord (maximum dose) compared with all the photon plans, except 3-field 3DCRT in cord maximum dose. In addition, MS PT also provides lower doses to the right kidney (mean and V{sub 18} {sub Gy}), liver (mean dose), total bowel (V{sub 20} {sub Gy} and mean dose), and small bowel (V{sub 15} {sub Gy} absolute volume ratio) compared with all the photon plans and PS PT. The dosimetric advantage of PT points to the possibility of treating tumor bed and comprehensive nodal areas while providing a more tolerable treatment course that could be used for dose escalation and combining with radiosensitizing chemotherapy.

  12. Fluence field modulated CT on a clinical TomoTherapy radiation therapy machine

    NASA Astrophysics Data System (ADS)

    Szczykutowicz, Timothy P.; Hermus, James

    2015-03-01

    Purpose: The multi-leaf collimator (MLC) assembly present on TomoTherapy (Accuray, Madison WI) radiation therapy (RT) and mega voltage CT machines is well suited to perform fluence field modulated CT (FFMCT). In addition, there is a demand in the RT environment for FFMCT imaging techniques, specifically volume of interest (VOI) imaging. Methods: A clinical TomoTherapy machine was programmed to deliver 30% imaging dose outside predefined VOIs. Four different size ROIs were placed at varying distances from isocenter. Projections intersecting the VOI received "full dose" while those not intersecting the VOI received 30% of the dose (i.e. the incident fluence for non VOI projections was 30% of the incident fluence for projections intersecting the VOI). Additional scans without fluence field modulation were acquired at "full" and 30% dose. The noise (pixel standard deviation) was measured inside the VOI region and compared between the three scans. Results: The VOI-FFMCT technique produced an image noise 1.09, 1.05, 1.05, and 1.21 times higher than the "full dose" scan for ROI sizes of 10 cm, 13 cm, 10 cm, and 6 cm respectively within the VOI region. Conclusions: Noise levels can be almost unchanged within clinically relevant VOIs sizes for RT applications while the integral imaging dose to the patient can be decreased, and/or the image quality in RT can be dramatically increased with no change in dose relative to non-FFMCT RT imaging. The ability to shift dose away from regions unimportant for clinical evaluation in order to improve image quality or reduce imaging dose has been demonstrated. This paper demonstrates that FFMCT can be performed using the MLC on a clinical TomoTherapy machine for the first time.

  13. Adaptive Radiation Therapy for Postprostatectomy Patients Using Real-Time Electromagnetic Target Motion Tracking During External Beam Radiation Therapy

    SciTech Connect

    Zhu, Mingyao; Bharat, Shyam; Michalski, Jeff M.; Gay, Hiram A.; Hou, Wei-Hsien; Parikh, Parag J.

    2013-03-15

    Purpose: Using real-time electromagnetic (EM) transponder tracking data recorded by the Calypso 4D Localization System, we report inter- and intrafractional target motion of the prostate bed, describe a strategy to evaluate treatment adequacy in postprostatectomy patients receiving intensity modulated radiation therapy (IMRT), and propose an adaptive workflow. Methods and Materials: Tracking data recorded by Calypso EM transponders was analyzed for postprostatectomy patients that underwent step-and-shoot IMRT. Rigid target motion parameters during beam delivery were calculated from recorded transponder positions in 16 patients with rigid transponder geometry. The delivered doses to the clinical target volume (CTV) were estimated from the planned dose matrix and the target motion for the first 3, 5, 10, and all fractions. Treatment adequacy was determined by comparing the delivered minimum dose (D{sub min}) with the planned D{sub min} to the CTV. Treatments were considered adequate if the delivered CTV D{sub min} is at least 95% of the planned CTV D{sub min}. Results: Translational target motion was minimal for all 16 patients (mean: 0.02 cm; range: −0.12 cm to 0.07 cm). Rotational motion was patient-specific, and maximum pitch, yaw, and roll were 12.2, 4.1, and 10.5°, respectively. We observed inadequate treatments in 5 patients. In these treatments, we observed greater target rotations along with large distances between the CTV centroid and transponder centroid. The treatment adequacy from the initial 10 fractions successfully predicted the overall adequacy in 4 of 5 inadequate treatments and 10 of 11 adequate treatments. Conclusion: Target rotational motion could cause underdosage to partial volume of the postprostatectomy targets. Our adaptive treatment strategy is applicable to post-prostatectomy patients receiving IMRT to evaluate and improve radiation therapy delivery.

  14. Cost-Effectiveness Analysis of Intensity Modulated Radiation Therapy Versus 3-Dimensional Conformal Radiation Therapy for Anal Cancer

    SciTech Connect

    Hodges, Joseph C.; Beg, Muhammad S.; Das, Prajnan; Meyer, Jeffrey

    2014-07-15

    Purpose: To compare the cost-effectiveness of intensity modulated radiation therapy (IMRT) and 3-dimensional conformal radiation therapy (3D-CRT) for anal cancer and determine disease, patient, and treatment parameters that influence the result. Methods and Materials: A Markov decision model was designed with the various disease states for the base case of a 65-year-old patient with anal cancer treated with either IMRT or 3D-CRT and concurrent chemotherapy. Health states accounting for rates of local failure, colostomy failure, treatment breaks, patient prognosis, acute and late toxicities, and the utility of toxicities were informed by existing literature and analyzed with deterministic and probabilistic sensitivity analysis. Results: In the base case, mean costs and quality-adjusted life expectancy in years (QALY) for IMRT and 3D-CRT were $32,291 (4.81) and $28,444 (4.78), respectively, resulting in an incremental cost-effectiveness ratio of $128,233/QALY for IMRT compared with 3D-CRT. Probabilistic sensitivity analysis found that IMRT was cost-effective in 22%, 47%, and 65% of iterations at willingness-to-pay thresholds of $50,000, $100,000, and $150,000 per QALY, respectively. Conclusions: In our base model, IMRT was a cost-ineffective strategy despite the reduced acute treatment toxicities and their associated costs of management. The model outcome was sensitive to variations in local and colostomy failure rates, as well as patient-reported utilities relating to acute toxicities.

  15. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a {sup 60}Co Magnetic Resonance Image Guidance Radiation Therapy System

    SciTech Connect

    Wooten, H. Omar Green, Olga; Yang, Min; DeWees, Todd; Kashani, Rojano; Olsen, Jeff; Michalski, Jeff; Yang, Deshan; Tanderup, Kari; Hu, Yanle; Li, H. Harold; Mutic, Sasa

    2015-07-15

    Purpose: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating {sup 60}Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. Methods and Materials: The ViewRay treatment planning system (Oakwood Village, OH) was used to create {sup 60}Co IMRT treatment plans for 33 cancer patients with disease in the abdominal, pelvic, thorax, and head and neck regions using physician-specified patient-specific target coverage and organ at risk (OAR) objectives. Backup plans using a third-party linear accelerator (linac)-based planning system were also created. Plans were evaluated by attending physicians and approved for treatment. The {sup 60}Co and linac plans were compared by evaluating conformity numbers (CN) with 100% and 95% of prescription reference doses and heterogeneity indices (HI) for planning target volumes (PTVs) and maximum, mean, and dose-volume histogram (DVH) values for OARs. Results: All {sup 60}Co IMRT plans achieved PTV coverage and OAR sparing that were similar to linac plans. PTV conformity for {sup 60}Co was within <1% and 3% of linac plans for 100% and 95% prescription reference isodoses, respectively, and heterogeneity was on average 4% greater. Comparisons of OAR mean dose showed generally better sparing with linac plans in the low-dose range <20 Gy, but comparable sparing for organs with mean doses >20 Gy. The mean doses for all {sup 60}Co plan OARs were within clinical tolerances. Conclusions: A commercial {sup 60}Co MR-IGRT device can produce highly conformal IMRT treatment plans similar in quality to linac IMRT for a variety of disease sites. Additional work is in progress to evaluate the clinical benefit of other novel features of this MR-IGRT system.

  16. A Phase III Study of Conventional Radiation Therapy Plus Thalidomide Versus Conventional Radiation Therapy for Multiple Brain Metastases (RTOG 0118)

    SciTech Connect

    Knisely, Jonathan P.S. Berkey, Brian; Chakravarti, Arnab; Yung, Al W.K.; Curran, Walter J.; Robins, H. Ian; Movsas, Benjamin; Brachman, David G.; Henderson, Randall H.; Mehta, Minesh P.

    2008-05-01

    Purpose: To compare whole-brain radiation therapy (WBRT) with WBRT combined with thalidomide for patients with brain metastases not amenable to resection or radiosurgery. Patients and Methods: Patients with Zubrod performance status 0-1, MRI-documented multiple (>3), large (>4 cm), or midbrain brain metastases arising from a histopathologically confirmed extracranial primary tumor, and an anticipated survival of >8 weeks were randomized to receive WBRT to a dose of 37.5 Gy in 15 fractions with or without thalidomide during and after WBRT. Prerandomization stratification used Radiation Therapy Oncology Group (RTOG) Recursive Partitioning Analysis (RPA) Class and whether post-WBRT chemotherapy was planned. Endpoints included overall survival, progression-free survival, time to neurocognitive progression, the cause of death, toxicities, and quality of life. A protocol-planned interim analysis documented that the trial had an extremely low probability of ever showing a significant difference favoring the thalidomide arm given the results at the time of the analysis, and it was therefore closed on the basis of predefined statistical guidelines. Results: Enrolled in the study were 332 patients. Of 183 accrued patients, 93 were randomized to receive WBRT alone and 90 to WBRT and thalidomide. Median survival was 3.9 months for both arms. No novel toxicities were seen, but thalidomide was not well tolerated in this population. Forty-eight percent of patients discontinued thalidomide because of side effects. Conclusion: Thalidomide provided no survival benefit for patients with multiple, large, or midbrain metastases when combined with WBRT; nearly half the patients discontinued thalidomide due to side effects.

  17. A review on photoneutrons characteristics in radiation therapy with high-energy photon beams

    PubMed Central

    Naseri, Alireza; Mesbahi, Asghar

    2010-01-01

    In radiation therapy with high-energy photon beams (E > 10 MeV) neutrons are generated mainly in linacs head thorough (γ,n) interactions of photons with nuclei of high atomic number materials that constitute the linac head and the beam collimation system. These neutrons affect the shielding requirements in radiation therapy rooms and also increase the out-of-field radiation dose of patients undergoing radiation therapy with high-energy photon beams. In the current review, the authors describe the factors influencing the neutron production for different medical linacs based on the performed measurements and Monte Carlo studies in the literature. PMID:24376940

  18. The Role of Hypofractionated Radiation Therapy with Photons, Protons, and Heavy Ions for Treating Extracranial Lesions

    PubMed Central

    Laine, Aaron Michael; Pompos, Arnold; Timmerman, Robert; Jiang, Steve; Story, Michael D.; Pistenmaa, David; Choy, Hak

    2016-01-01

    Traditionally, the ability to deliver large doses of ionizing radiation to a tumor has been limited by radiation-induced toxicity to normal surrounding tissues. This was the initial impetus for the development of conventionally fractionated radiation therapy, where large volumes of healthy tissue received radiation and were allowed the time to repair the radiation damage. However, advances in radiation delivery techniques and image guidance have allowed for more ablative doses of radiation to be delivered in a very accurate, conformal, and safe manner with shortened fractionation schemes. Hypofractionated regimens with photons have already transformed how certain tumor types are treated with radiation therapy. Additionally, hypofractionation is able to deliver a complete course of ablative radiation therapy over a shorter period of time compared to conventional fractionation regimens making treatment more convenient to the patient and potentially more cost-effective. Recently, there has been an increased interest in proton therapy because of the potential further improvement in dose distributions achievable due to their unique physical characteristics. Furthermore, with heavier ions the dose conformality is increased and, in addition, there is potentially a higher biological effectiveness compared to protons and photons. Due to the properties mentioned above, charged particle therapy has already become an attractive modality to further investigate the role of hypofractionation in the treatment of various tumors. This review will discuss the rationale and evolution of hypofractionated radiation therapy, the reported clinical success with initially photon and then charged particle modalities, and further potential implementation into treatment regimens going forward. PMID:26793619

  19. 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.

  20. Role of Definitive Radiation Therapy in Carcinoma of Unknown Primary in the Abdomen and Pelvis

    SciTech Connect

    Kelly, Patrick; Das, Prajnan; Varadhachary, Gauri R.; Fontanilla, Hiral P.; Krishnan, Sunil; Delclos, Marc E.; Jhingran, Anuja; Eifel, Patricia J.; Crane, Christopher H.

    2012-04-01

    Objectives: Carcinoma of unknown primary (CUP) in the abdomen and pelvis is a heterogeneous group of cancers with no standard treatment. Considered by many to be incurable, these patients are often treated with chemotherapy alone. In this study, we determined the effectiveness of radiation therapy in combination with chemotherapy in patients with CUP in the abdomen and pelvis. Patients and Methods: Medical records were reviewed for 37 patients with CUP treated with radiation therapy for disease located in the soft tissues and/or nodal basins of the abdomen and pelvis at University of Texas M.D. Anderson Cancer between 2002 and 2009. All patients underwent chemotherapy, either before or concurrent with radiation therapy. Patients were selected for radiation therapy on the basis of histologic type, disease extent, and prior therapy response. Twenty patients underwent definitive radiation therapy (defined as radiation therapy targeting all known disease sites with at least 45 Gy) and 17 patients underwent palliative radiation therapy. Only 6 patients had surgical resection of their disease. Patient and treatment characteristics were extracted and the endpoints of local disease control, progression-free survival (PFS), overall survival (OS), and treatment-related toxicity incidence were analyzed. Results: The 2-year PFS and OS rates for the entire cohort were 32% and 57%, respectively. However, in patients treated with definitive radiation therapy, the rates were 48% and 76%, and 7 patients lived more than 3 years after treatment with no evidence of disease progression. Nevertheless, radiation-associated toxicity was significant in this cohort, as 40% experienced Grade 2 or higher late toxicities. Conclusions: The use of definitive radiation therapy should be considered in selected patients with CUP in the soft tissues or nodal basins of the abdomen and pelvis.

  1. Identification of Amyloid Plaques in Retinas from Alzheimer’s Patients and Noninvasive In Vivo Optical Imaging of Retinal Plaques in a Mouse Model

    PubMed Central

    Koronyo-Hamaoui, Maya; Koronyo, Yosef; Ljubimov, Alexander V.; Miller, Carol A.; Ko, MinHee K.; Black, Keith L.; Schwartz, Michal; Farkas, Daniel L.

    2010-01-01

    Noninvasive monitoring of β-amyloid (Aβ) plaques, the neuropathological hallmarks of Alzheimer's disease (AD), is critical for AD diagnosis and prognosis. Current visualization of Aβ plaques in brains of live patients and animal models is limited in specificity and resolution. The retina as an extension of the brain portrays an appealing target for a live, noninvasive optical imaging of AD if disease pathology is manifested there. We identified retinal Aβ plaques in postmortem eyes from AD patients (n=8) and in suspected early stage cases (n=5), consistent with brain pathology and clinical reports; plaques were undetectable in age-matched non-AD individuals (n=5). In APPSWE/PS1ΔE9 transgenic mice (AD-Tg; n=18) and not in non-Tg wt mice (n=10), retinal Aβ plaques were detected following systemic administration of curcumin, a safe plaque-labeling fluorochrome. Moreover, retinal plaques were detectable earlier than in the brain and accumulated with disease progression. An immune-based therapy effective in reducing brain plaques, significantly reduced retinal Aβ plaque burden in immunized versus non-immunized AD mice (n=4 mice per group). In live AD-Tg mice (n=24), systemic administration of curcumin allowed noninvasive optical imaging of retinal Aβ plaques in vivo with high resolution and specificity; plaques were undetectable in non-Tg wt mice (n=11). Our discovery of Aβ specific plaques in retinas from AD patients, and the ability to noninvasively detect individual retinal plaques in live AD mice establish the basis for developing high resolution optical imaging for early AD diagnosis, prognosis assessment and response to therapies. PMID:20550967

  2. Rat liver tolerance for partial resection and intraoperative radiation therapy: Regeneration is radiation dose dependent

    SciTech Connect

    Bossola, M.; Merrick, H.W.; Eltaki, A.; Bellantone, R.; Milligan, A.J.; Doglietto, G.B.; Conran, P.; Dobelbower, R.R. Jr.; Crucitti, F. )

    1990-11-01

    We studied the feasibility of delivering a large single dose of intraoperative radiation as an adjuvant to partial hepatic resection. Intraoperative radiation therapy (IORT) was delivered to the remaining liver of 84 rats after partial hepatectomy to determine the acute and chronic effects of treatment on blood chemistry values, histology, survival, hepatic regeneration, and cellular appearance of the normal liver. Transient elevations in SGOT, SGPT, and alkaline phosphatase were attributed both to hepatectomy and to liver parenchymal damage induced by IORT. Microscopic examination upon necropsy, performed at frequent intervals post-treatment revealed hepatic capsular thickening with some alteration of liver architecture mainly underneath the capsule, with localized inflammation and some areas of necrosis. Survival in all groups was 100% at 45 days. Liver weight increase proved to be dose-dependent and displayed a bisphasic pattern. This study demonstrated that IORT is a feasible adjunct to surgical resection of the liver in the rat model.

  3. Neutron, Proton, and Photonuclear Cross Sections for Radiation Therapy and Radiation Protection

    SciTech Connect

    Chadwick, M.B.

    1998-09-10

    The authors review recent work at Los Alamos to evaluate neutron, proton, and photonuclear cross section up to 150 MeV (to 250 MeV for protons), based on experimental data and nuclear model calculations. These data are represented in the ENDF format and can be used in computer codes to simulate radiation transport. They permit calculations of absorbed dose in the body from therapy beams, and through use of kerma coefficients allow absorbed dose to be estimated for a given neutron energy distribution. For radiation protection, these data can be used to determine shielding requirements in accelerator environments, and to calculate neutron, proton, gamma-ray, and radionuclide production. Illustrative comparisons of the evaluated cross section and kerma coefficient data with measurements are given.

  4. Modern Radiation Therapy for Primary Cutaneous Lymphomas: Field and Dose Guidelines From the International Lymphoma Radiation Oncology Group

    SciTech Connect

    Specht, Lena; Dabaja, Bouthaina; Illidge, Tim; Wilson, Lynn D.; Hoppe, Richard T.

    2015-05-01

    Primary cutaneous lymphomas are a heterogeneous group of diseases. They often remain localized, and they generally have a more indolent course and a better prognosis than lymphomas in other locations. They are highly radiosensitive, and radiation therapy is an important part of the treatment, either as the sole treatment or as part of a multimodality approach. Radiation therapy of primary cutaneous lymphomas requires the use of special techniques that form the focus of these guidelines. The International Lymphoma Radiation Oncology Group has developed these guidelines after multinational meetings and analysis of available evidence. The guidelines represent an agreed consensus view of the International Lymphoma Radiation Oncology Group steering committee on the use of radiation therapy in primary cutaneous lymphomas in the modern era.

  5. Radiation therapy of penile cancer: six to ten-year follow-up.

    PubMed

    Grabstald, H; Kelley, C D

    1980-06-01

    Ten patients with penile cancer were treated with radiation therapy between 1968 and 1973. Nine of ten remain free of disease though in 1 patient a new penile primary developed eight years after the radiation therapy and was treated by partial penectomy. One patient died following surgery for "bleeding ulcer." He was free of penile cancer five years after radiation. The most common complication is urethral stricture and skin telangiectasia. PMID:7394983

  6. Acute effects of radiation therapy on indium-111-labeled leukocyte uptake in bone marrow

    SciTech Connect

    Palestro, C.J.; Kim, C.K.; Vega, A.; Goldsmith, S.J. )

    1989-11-01

    We recently performed ({sup 99m}Tc)MDP bone and {sup 111}In-labeled leukocyte scintigraphy on a patient receiving radiation therapy to the lower cervical and upper thoracic spine. While the bone images revealed only minimally increased activity in the radiation port, leukocyte images revealed diffuse, intensely increased uptake in this same region. Radiation therapy should be included in the differential diagnosis of increased bone marrow activity on {sup 111}In leukocyte images.

  7. Benzydamine hydrochloride in prevention and management of pain in oral mucositis associated with radiation therapy

    SciTech Connect

    Epstein, J.B.; Stevenson-Moore, P.

    1986-08-01

    Benzydamine hydrochloride rinse reduced pain associated with radiation mucositis when it was used during the course of radiation therapy. Fewer patients using benzydamine rinse required systemic analgesics. All patients using benzydamine tolerated the rinse well and continued with regular rinsing throughout the course of radiation therapy. Benzydamine hydrochloride is currently undergoing clinical trials in the United States for application for approval from the Food and Drug Administration.

  8. Applications of Cherenkov Light Emission for Dosimetry in Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Glaser, Adam Kenneth

    Since its discovery in the 1930's, the Cherenkov effect has been paramount in the development of high-energy physics research. It results in light emission from charged particles traveling faster than the local speed of light in a dielectric medium. The ability of this emitted light to describe a charged particle's trajectory, energy, velocity, and mass has allowed scientists to study subatomic particles, detect neutrinos, and explore the properties of interstellar matter. However, only recently has the phenomenon been considered in the practical context of medical physics and radiation therapy dosimetry, where Cherenkov light is induced by clinical x-ray photon, electron, and proton beams. To investigate the relationship between this phenomenon and dose deposition, a Monte Carlo plug-in was developed within the Geant4 architecture for medically-oriented simulations (GAMOS) to simulate radiation-induced optical emission in biological media. Using this simulation framework, it was determined that Cherenkov light emission may be well suited for radiation dosimetry of clinically used x-ray photon beams. To advance this application, several novel techniques were implemented to realize the maximum potential of the signal, such as time-gating for maximizing the signal to noise ratio (SNR) and Cherenkov-excited fluorescence for generating isotropic light release in water. Proof of concept experiments were conducted in water tanks to demonstrate the feasibility of the proposed method for two-dimensional (2D) projection imaging, three-dimensional (3D) parallel beam tomography, large field of view 3D cone beam tomography, and video-rate dynamic imaging of treatment plans for a number of common radiotherapy applications. The proposed dosimetry method was found to have a number of unique advantages, including but not limited to its non-invasive nature, water-equivalence, speed, high-resolution, ability to provide full 3D data, and potential to yield data in-vivo. Based on these preliminary results, it is expected that Cherenkov light emission may prove to be a useful tool for radiation dosimetry with both research and clinical applications.

  9. Radiation-Induced Lymphocyte Apoptosis to Predict Radiation Therapy Late Toxicity in Prostate Cancer Patients

    SciTech Connect

    Schnarr, Kara; Boreham, Douglas; Sathya, Jinka; Julian, Jim; Dayes, Ian S.

    2009-08-01

    Purpose: To examine a potential correlation between the in vitro apoptotic response of lymphocytes to radiation and the risk of developing late gastrointestinal (GI)/genitourinary (GU) toxicity from radiotherapy for prostate cancer. Methods and Materials: Prostate cancer patients formerly enrolled in a randomized study were tested for radiosensitivity by using a radiation-induced lymphocyte apoptosis assay. Apoptosis was measured using flow cytometry-based Annexin-FITC/7AAD and DiOC{sub 6}/7AAD assays in subpopulations of lymphocytes (total lymphocytes, CD4+, CD8+ and CD4-/CD8-) after exposure to an in vitro dose of 0, 2, 4, or 8 Gy. Results: Patients with late toxicity after radiotherapy showed lower lymphocyte apoptotic responses to 8 Gy than patients who had not developed late toxicity (p = 0.01). All patients with late toxicity had apoptosis levels that were at or below the group mean. The negative predictive value in both apoptosis assays ranged from 95% to 100%, with sensitivity values of 83% to 100%. Apoptosis at lower dose points and in lymphocyte subpopulations had a weaker correlation with the occurrence of late toxicity. Conclusions: Lymphocyte apoptosis after 8 Gy of radiation has the potential to predict which patients will be spared late toxicity after radiation therapy. Further research should be performed to identify the specific subset of lymphocytes that correlates with late toxicity, followed by a corresponding prospective study.

  10. Managing Radiation Therapy Side Effects: What to Do about Feeling Sick to Your Stomach and Throwing Up (Nausea and ...

    MedlinePlus

    ... ational C ancer I nstitute Managing Radiation Therapy Side Effects What To Do About Feeling Sick to Your ... down before you eat it. Managing Radiation Therapy Side Effects: Feeling Sick to Your Stomach and Throwing Up ( ...

  11. Radiation therapy for Bowen's disease of the skin

    SciTech Connect

    Lukas VanderSpek, Lauren A. . E-mail: lauren.vanderspek@lrcc.on.ca; Pond, Gregory R.; Wells, Woodrow; Tsang, Richard W.

    2005-10-01

    Purpose: To assess the clinical outcome in the radiation therapy (RT) of squamous carcinoma in situ of the skin (Bowen's disease). We focused on the local control rate and the toxicity according to the biologically effective dose (BED). Methods and Materials: A retrospective review was performed on 44 patients with Bowen's disease treated at Princess Margaret Hospital from April 1985 to November 2000. RT was the primary treatment for 32 patients, whereas 12 received RT for residual disease after local ablative therapy. Lesions were located as follows: scalp, 9 patients (20%); face, 12 (27%); trunk, 6 (14%), extremity, 12 (27%), perianal, 3 (7%), and penis, 2 (5%). Orthovoltage X-rays were used in the majority (39 of 44, 89%). There was no standard fractionation regimen: some physicians prescribed high doses, as for invasive skin cancer, whereas others prescribed lower doses because of the noninvasive nature of the disease, a sensitive anatomic location (e.g., extremity), or large treatment area. Because of the variations in fractionation regimens, BED was used as a common metric for biologic effect in the comparison of different regimens and analyzed for correlation with recurrence and toxicity. Local control was defined as the lack of persistent or recurrent disease at the treated site for the follow-up period. Grade 4 toxicity was defined as necrosis (cartilage/bone damage) and/or ulceration for a duration of >3 months. Results: The mean patient age was 67.7 years, and the male/female ratio was 29:15. The median pretreatment lesion size was 2.65 cm{sup 2} (range, 0.07-34.56 cm{sup 2}). Complete remission was achieved in 42 patients, with follow-up unavailable for the remaining 2 patients. Subsequently, 3 patients experienced recurrences at 0.2, 1.1, and 1-1.5 years after complete remission. One recurrence was Bowen's disease (local); the others were squamous cell carcinoma (one local, one marginal). Four patients experienced a new squamous lesion at a distant cutaneous site. As of last follow-up, 32 patients (73%) were known to be alive. Median follow-up was 2.6 years (range, 0-11.8 years). All but 3 patients were disease-free at last follow-up, 1 of whom died with distant, but not local disease. The 5-year overall survival rate was 68%. Biologically effective dose was not associated with recurrence. The crude local control rate was 93%. There was a trend toward higher radiation doses for smaller pretreatment tumor and field sizes. The BED did not correlate with Grade 4 toxicity; however, the three cases of Grade 4 toxicity occurred in patients treated with hypofractionated regimens (dose per fraction >4 Gy) for extremity lesions. Conclusions: Radiation therapy is an effective treatment option for Bowen's disease of the skin. Local recurrences seem to be equally low in patients treated with high- and low-dose regimens. Avoiding hypofractionated regimens (dose per fraction >4 Gy) in extremity locations might reduce the risk of Grade 4 toxicity.

  12. Immunotherapy and radiation therapy: considerations for successfully combining radiation into the paradigm of immuno-oncology drug development.

    PubMed

    Sharon, Elad; Polley, Mei-Yin; Bernstein, Michael B; Ahmed, Mansoor

    2014-08-01

    As the immunotherapy of cancer comes of age, adding immunotherapeutic agents to radiation therapy has the potential to improve the outcomes for patients with a wide variety of malignancies. Despite the enormous potential of such combination therapy, laboratory data has been lacking and there is little guidance for pursuing novel treatment strategies. Animal models have significant limitation in combining radiation therapy with immunotherapy and some of the limitations of preclinical models are discussed in this article. In addition to the preclinical challenges, radiation therapy and immunotherapy combinations may have overlapping toxicities, and for both types of therapy, early and late manifestations of toxicity are possible. Given these risks, special attention should be given to the design of the specific Phase I clinical trial that is chosen. In this article, we describe several Phase I design possibilities that may be employed, including the 3 + 3 design (also known as the cohort of 3 design), the continual reassessment method (CRM), and the time-to-event continual reassessment method (TITE-CRM). Efficacy end points for further development of combination therapy must be based on multiple factors, including disease type, stage of disease, the setting of therapy and the goal of therapy. While the designs for future clinical trials will vary, it is clear that these two successful modalities of therapy can and should be combined for the benefit of cancer patients. PMID:25003314

  13. Real-time dosimetry in external beam radiation therapy

    PubMed Central

    Prabhakar, Ramachandran

    2013-01-01

    With growing complexity in radiotherapy treatment delivery, it has become mandatory to check each and every treatment plan before implementing clinically. This process is currently administered by an independent secondary check of all treatment parameters and as a pre-treatment quality assurance (QA) check for intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy treatment plans. Although pre-treatment IMRT QA is aimed to ensure the correct dose is delivered to the patient, it does not necessarily predict the clinically relevant patient dose errors. During radiotherapy, treatment uncertainties can affect tumor control and may increase complications to surrounding normal tissues. To combat this, image guided radiotherapy is employed to help ensure the plan conditions are mimicked on the treatment machine. However, it does not provide information on actual delivered dose to the tumor volume. Knowledge of actual dose delivered during treatment aid in confirming the prescribed dose and also to replan/reassess the treatment in situations where the planned dose is not delivered as expected by the treating physician. Major accidents in radiotherapy would have been averted if real time dosimetry is incorporated as part of the routine radiotherapy procedure. Of late real-time dosimetry is becoming popular with complex treatments in radiotherapy. Real-time dosimetry can be either in the form of point doses or planar doses or projected on to a 3D image dataset to obtain volumetric dose. They either provide entrance dose or exit dose or dose inside the natural cavities of a patient. In external beam radiotherapy, there are four different established platforms whereby the delivered dose information can be obtained: (1) Collimator; (2) Patient; (3) Couch; and (4) Electronic Portal Imaging Device. Current real-time dosimetric techniques available in radiotherapy have their own advantages and disadvantages and a combination of one or more of these methods provide vital information about the actual dose delivered to radiotherapy patients. PMID:24179630

  14. Hypofractionated Radiation Therapy for Breast Ductal Carcinoma In Situ

    SciTech Connect

    Hathout, Lara; Hijal, Tarek; Théberge, Valérie; Fortin, Bernard; Vulpe, Horia; Hogue, Jean-Charles; Lambert, Christine; Bahig, Houda; and others

    2013-12-01

    Purpose: Conventional radiation therapy (RT) administered in 25 fractions after breast-conserving surgery (BCS) is the standard treatment for ductal carcinoma in situ (DCIS) of the breast. Although accelerated hypofractionated regimens in 16 fractions have been shown to be equivalent to conventional RT for invasive breast cancer, few studies have reported results of using hypofractionated RT in DCIS. Methods and Materials: In this multicenter collaborative effort, we retrospectively reviewed the records of all women with DCIS at 3 institutions treated with BCS followed by hypofractionated whole-breast RT (WBRT) delivered in 16 fractions. Results: Between 2003 and 2010, 440 patients with DCIS underwent BCS followed by hypofractionated WBRT in 16 fractions for a total dose of 42.5 Gy (2.66 Gy per fraction). Boost RT to the surgical bed was given to 125 patients (28%) at a median dose of 10 Gy in 4 fractions (2.5 Gy per fraction). After a median follow-up time of 4.4 years, 14 patients had an ipsilateral local relapse, resulting in a local recurrence-free survival of 97% at 5 years. Positive surgical margins, high nuclear grade, age less than 50 years, and a premenopausal status were all statistically associated with an increased occurrence of local recurrence. Tumor hormone receptor status, use of adjuvant hormonal therapy, and administration of additional boost RT did not have an impact on local control in our cohort. On multivariate analysis, positive margins, premenopausal status, and nuclear grade 3 tumors had a statistically significant worse local control rate. Conclusions: Hypofractionated RT using 42.5 Gy in 16 fractions provides excellent local control for patients with DCIS undergoing BCS.

  15. Late radiation toxicity in Hodgkin lymphoma patients: proton therapy's potential.

    PubMed

    Toltz, Allison; Shin, Naomi; Mitrou, Ellis; Laude, Cecile; Freeman, Carolyn R; Seuntjens, Jan; Parker, William; Roberge, David

    2015-01-01

    In 2010, all young patients treated for intrathoracic Hodgkin lymphoma (HL) at one of 10 radiotherapy centers in the province of Quebec received 3D conformal photon therapy. These patients may now be at risk for late effects of their treatment, notably secondary malignancies and cardiac toxicity. We hypothesized that more complex radiotherapy, including intensity-modulated proton therapy (IMPT) and possibly IMRT (in the form of helical tomotherapy (HT)), could benefit these patients. With institutional review board approval at 10 institutions, all treatment plans for patients under the age of 30 treated for HL during a six-month consecutive period of 2010 were retrieved. Twenty-six patients were identified, and after excluding patients with extrathoracic radiation or treatment of recurrence, 20 patients were replanned for HT and IMPT. Neutron dose for IMPT plans was estimated from published measurements. The relative seriality model was used to predict excess risk of cardiac mortality. A modified linear quadratic model was used to predict the excess absolute risk for induction of lung cancer and, in female patients, breast cancer. Model parameters were derived from published data. Predicted risk for cardiac mortality was similar among the three treatment techniques (absolute excess risk of cardiac mortality was not reduced for HT or IMPT (p > 0.05, p > 0.05) as compared to 3D CRT). Predicted risks were increased for HT and reduced for IMPT for secondary lung cancer (p < 0.001, p < 0.001) and breast cancers (p< 0.001, p< 0.001) as compared to 3D CRT. PMID:26699298

  16. Projections onto the Pareto surface in multicriteria radiation therapy optimization

    SciTech Connect

    Bokrantz, Rasmus E-mail: rasmus.bokrantz@raysearchlabs.com; Miettinen, Kaisa

    2015-10-15

    Purpose: To eliminate or reduce the error to Pareto optimality that arises in Pareto surface navigation when the Pareto surface is approximated by a small number of plans. Methods: The authors propose to project the navigated plan onto the Pareto surface as a postprocessing step to the navigation. The projection attempts to find a Pareto optimal plan that is at least as good as or better than the initial navigated plan with respect to all objective functions. An augmented form of projection is also suggested where dose–volume histogram constraints are used to prevent that the projection causes a violation of some clinical goal. The projections were evaluated with respect to planning for intensity modulated radiation therapy delivered by step-and-shoot and sliding window and spot-scanned intensity modulated proton therapy. Retrospective plans were generated for a prostate and a head and neck case. Results: The projections led to improved dose conformity and better sparing of organs at risk (OARs) for all three delivery techniques and both patient cases. The mean dose to OARs decreased by 3.1 Gy on average for the unconstrained form of the projection and by 2.0 Gy on average when dose–volume histogram constraints were used. No consistent improvements in target homogeneity were observed. Conclusions: There are situations when Pareto navigation leaves room for improvement in OAR sparing and dose conformity, for example, if the approximation of the Pareto surface is coarse or the problem formulation has too permissive constraints. A projection onto the Pareto surface can identify an inaccurate Pareto surface representation and, if necessary, improve the quality of the navigated plan.

  17. Stereotactic Body Radiation Therapy in Recurrent Hepatocellular Carcinoma

    SciTech Connect

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

    2012-10-01

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

  18. Acute myelogenous leukemia following radiation therapy and chemotherapy for osteogenic sarcoma

    SciTech Connect

    Jacobs, A.D.; Gale, R.P.

    1984-06-01

    Patients receiving ionizing radiation therapy or cytotoxic chemotherapy are at increased risk of developing acute myelogenous leukemia. Ten cases of therapy-linked myelogenous leukemia have been reported in patients with sarcoma, and the authors report here the first case in a patient who received combined-modality therapy for treatment of an osteogenic sarcoma. As treatment for this disease becomes more intensive and survival improves, the incidence of leukemia following therapy for osteogenic sarcoma may increase.

  19. A practical three-dimensional dosimetry system for radiation therapy

    SciTech Connect

    Guo Pengyi; Adamovics, John; Oldham, Mark

    2006-10-15

    There is a pressing need for a practical three-dimensional (3D) dosimetry system, convenient for clinical use, and with the accuracy and resolution to enable comprehensive verification of the complex dose distributions typical of modern radiation therapy. Here we introduce a dosimetry system that can achieve this challenge, consisting of a radiochromic dosimeter (PRESAGE trade mark sign ) and a commercial optical computed tomography (CT) scanning system (OCTOPUS trade mark sign ). PRESAGE trade mark sign is a transparent material with compelling properties for dosimetry, including insensitivity of the dose response to atmospheric exposure, a solid texture negating the need for an external container (reducing edge effects), and amenability to accurate optical CT scanning due to radiochromic optical contrast as opposed to light-scattering contrast. An evaluation of the performance and viability of the PRESAGE trade mark sign /OCTOPUS, combination for routine clinical 3D dosimetry is presented. The performance of the two components (scanner and dosimeter) was investigated separately prior to full system test. The optical CT scanner has a spatial resolution of {<=}1 mm, geometric accuracy within 1 mm, and high reconstruction linearity (with a R{sup 2} value of 0.9979 and a standard error of estimation of {approx}1%) relative to independent measurement. The overall performance of the PRESAGE trade mark sign /OCTOPUS system was evaluated with respect to a simple known 3D dose distribution, by comparison with GAFCHROMIC[reg] EBT film and the calculated dose from a commissioned planning system. The 'measured' dose distribution in a cylindrical PRESAGE trade mark sign dosimeter (16 cm diameter and 11 cm height) was determined by optical-CT, using a filtered backprojection reconstruction algorithm. A three-way Gamma map comparison (4% dose difference and 4 mm distance to agreement), between the PRESAGE trade mark sign , EBT and calculated dose distributions, showed full agreement in measurable region of PRESAGE trade mark sign dosimeter ({approx}90% of radius). The EBT and PRESAGE trade mark sign distributions agreed more closely with each other than with the calculated plan, consistent with penumbral blurring in the planning data which was acquired with an ion chamber. In summary, our results support the conclusion that the PRESAGE trade mark sign optical-CT combination represents a significant step forward in 3D dosimetry, and provides a robust, clinically effective and viable high-resolution relative 3D dosimetry system for radiation therapy.

  20. Dosimetric comparison of volumetric modulated arc therapy with robotic stereotactic radiation therapy in hepatocellular carcinoma

    PubMed Central

    Paik, Eun Kyung; Choi, Chul Won; Jang, Won Il; Lee, Sung Hyun; Choi, Sang Hyoun; Kim, Kum Bae; Lee, Dong Han

    2015-01-01

    Purpose To compare volumetric modulated arc therapy of RapidArc with robotic stereotactic body radiation therapy (SBRT) of CyberKnife in the planning and delivery of SBRT for hepatocellular carcinoma (HCC) treatment by analyzing dosimetric parameters. Materials and Methods Two radiation treatment plans were generated for 29 HCC patients, one using Eclipse for the RapidArc plan and the other using Multiplan for the CyberKnife plan. The prescription dose was 60 Gy in 3 fractions. The dosimetric parameters of planning target volume (PTV) coverage and normal tissue sparing in the RapidArc and the CyberKnife plans were analyzed. Results The conformity index was 1.05 ± 0.02 for the CyberKnife plan, and 1.13 ± 0.10 for the RapidArc plan. The homogeneity index was 1.23 ± 0.01 for the CyberKnife plan, and 1.10 ± 0.03 for the RapidArc plan. For the normal liver, there were significant differences between the two plans in the low-dose regions of V1 and V3. The normalized volumes of V60 for the normal liver in the RapidArc plan were drastically increased when the mean dose of the PTVs in RapidArc plan is equivalent to the mean dose of the PTVs in the CyberKnife plan. Conclusion CyberKnife plans show greater dose conformity, especially in small-sized tumors, while RapidArc plans show good dosimetric distribution of low dose sparing in the normal liver and body. PMID:26484307

  1. Proton Radiation Therapy for the Treatment of Retinoblastoma

    SciTech Connect

    Mouw, Kent W.; Sethi, Roshan V.; Yeap, Beow Y.; MacDonald, Shannon M.; Chen, Yen-Lin E.; Tarbell, Nancy J.; Yock, Torunn I.; Munzenrider, John E.; Adams, Judith; Grabowski, Eric; Mukai, Shizuo; Shih, Helen A.

    2014-11-15

    Purpose: To investigate long-term disease and toxicity outcomes for pediatric retinoblastoma patients treated with proton radiation therapy (PRT). Methods and Materials: This is a retrospective analysis of 49 retinoblastoma patients (60 eyes) treated with PRT between 1986 and 2012. Results: The majority (84%) of patients had bilateral disease, and nearly half (45%) had received prior chemotherapy. At a median follow-up of 8 years (range, 1-24 years), no patients died of retinoblastoma or developed metastatic disease. The post-PRT enucleation rate was low (18%), especially in patients with early-stage disease (11% for patients with International Classification for Intraocular Retinoblastoma [ICIR] stage A-B disease vs 23% for patients with ICIR stage C-D disease). Post-PRT ophthalmologic follow-up was available for 61% of the preserved eyes (30 of 49): 14 of 30 eyes (47%) had 20/40 visual acuity or better, 7 of 30 (23%) had moderate visual acuity (20/40-20/600), and 9 of 30 (30%) had little or no useful vision (worse than 20/600). Twelve of 60 treated eyes (20%) experienced a post-PRT event requiring intervention, with cataracts the most common (4 eyes). No patients developed an in-field second malignancy. Conclusions: Long-term follow-up of retinoblastoma patients treated with PRT demonstrates that PRT can achieve high local control rates, even in advanced cases, and many patients retain useful vision in the treated eye. Treatment-related ocular side effects were uncommon, and no radiation-associated malignancies were observed.

  2. Adjuvant Radiation Therapy Treatment Time Impacts Overall Survival in Gastric Cancer

    SciTech Connect

    McMillan, Matthew T.; Ojerholm, Eric; Roses, Robert E.; Plastaras, John P.; Metz, James M.; Mamtani, Ronac; Stripp, Diana; Ben-Josef, Edgar; Datta, Jashodeep

    2015-10-01

    Purpose: Prolonged radiation therapy treatment time (RTT) is associated with worse survival in several tumor types. This study investigated whether delays during adjuvant radiation therapy impact overall survival (OS) in gastric cancer. Methods and Materials: The National Cancer Data Base was queried for patients with resected gastric cancer who received adjuvant radiation therapy with National Comprehensive Cancer Network–recommended doses (45 or 50.4 Gy) between 1998 and 2006. RTT was classified as standard (45 Gy: 33-36 days, 50.4 Gy: 38-41 days) or prolonged (45 Gy: >36 days, 50.4 Gy: >41 days). Cox proportional hazards models evaluated the association between the following factors and OS: RTT, interval from surgery to radiation therapy initiation, interval from surgery to radiation therapy completion, radiation therapy dose, demographic/pathologic and operative factors, and other elements of adjuvant multimodality therapy. Results: Of 1591 patients, RTT was delayed in 732 (46%). Factors associated with prolonged RTT were non-private health insurance (OR 1.3, P=.005) and treatment at non-academic facilities (OR 1.2, P=.045). Median OS and 5-year actuarial survival were significantly worse in patients with prolonged RTT compared with standard RTT (36 vs 51 months, P=.001; 39 vs 47%, P=.005); OS worsened with each cumulative week of delay (P<.0004). On multivariable analysis, prolonged RTT was associated with inferior OS (hazard ratio 1.2, P=.002); the intervals from surgery to radiation therapy initiation or completion were not. Prolonged RTT was particularly detrimental in patients with node positivity, inadequate nodal staging (<15 nodes examined), and those undergoing a cycle of chemotherapy before chemoradiation therapy. Conclusions: Delays during adjuvant radiation therapy appear to negatively impact survival in gastric cancer. Efforts to minimize cumulative interruptions to <7 days should be considered.

  3. Novel radiotherapy approaches for lung cancer: combining radiation therapy with targeted and immunotherapies

    PubMed Central

    Simone, Charles B.; Burri, Stuart H.

    2015-01-01

    Targeted therapies and immunotherapies have quickly become fixtures in the treatment armamentarium for metastatic non-small cell lung cancer (NSCLC). Targeted therapies directed against epidermal growth factor receptor (EGFR) mutations, anaplastic lymphoma kinase (ALK) translocations, and ROS-1 rearrangements have demonstrated improved progression free survival (PFS) and, in selected populations, improved overall survival (OS) compared with cytotoxic chemotherapy. Immunotherapies, including checkpoint inhibitor monoclonal antibodies against programmed death receptor 1 (PD-1) and programmed death ligand 1 (PD-L1), have now also demonstrated improved survival compared with chemotherapy. The use of these novel systemic agents in non-metastatic patient populations and in combination with radiation therapy is not well defined. As radiation therapy has become more effective and more conformal with fewer toxicities, it has increasingly been used in the oligometastatic or oligoprogression setting. This has allowed improvement in PFS and potentially OS, and in the oligoprogressive setting may overcome acquired drug resistance of a specific lesion(s) to allow patients to remain on their targeted therapies. Molecularly targeted therapies and immunotherapies for patients with metastatic NSCLC have demonstrated much success. Advances in radiation therapy and stereotactic body radiotherapy, radiation therapy have led to combination strategies with targeted therapies among patients with lung cancer. Radiation therapy has also been combined with immunotherapies predominantly in the metastatic setting. In the metastatic population, radiation therapy has the ability to provide durable local control and also augment the immune response of systemic agents, which may lead to an abscopal effect of immune-mediated tumor response in disease sites outside of the radiation field in select patients. PMID:26629423

  4. Paclitaxel Through the Ages of Anticancer Therapy: Exploring Its Role in Chemoresistance and Radiation Therapy

    PubMed Central

    Barbuti, Anna Maria; Chen, Zhe-Sheng

    2015-01-01

    Paclitaxel (Taxol®) is a member of the taxane class of anticancer drugs and one of the most common chemotherapeutic agents used against many forms of cancer. Paclitaxel is a microtubule-stabilizer that selectively arrests cells in the G2/M phase of the cell cycle, and found to induce cytotoxicity in a time and concentration-dependent manner. Paclitaxel has been embedded in novel drug formulations, including albumin and polymeric micelle nanoparticles, and applied to many anticancer treatment regimens due to its mechanism of action and radiation sensitizing effects. Though paclitaxel is a major anticancer drug which has been used for many years in clinical treatments, its therapeutic efficacy can be limited by common encumbrances faced by anticancer drugs. These encumbrances include toxicities, de novo refraction, and acquired multidrug resistance (MDR). This article will give a current and comprehensive review of paclitaxel, beginning with its unique history and pharmacology, explore its mechanisms of drug resistance and influence in combination with radiation therapy, while highlighting current treatment regimens, formulations, and new discoveries. PMID:26633515

  5. Malignant melanoma: analysis of dose fractionation in radiation therapy

    SciTech Connect

    Konefal, J.B.; Emami, B.; Pilepich, M.V.

    1987-09-01

    Thirty-five patients with 67 measureable cutaneous or lymph node metastases from malignant melanoma were treated with radiation therapy in a variety of total doses and dose fractions. There was no correlation between total dose and response rate. However, there was a strong correlation between fraction size and response rate. There were four (9%) complete responses in 43 lesions treated with fractions less than or equal to 500 rad (5 Gy) compared with 12 (50%) complete responses in 24 lesions treated with fractions greater than 500 rad (5 Gy) (P = .0006). Initial response rate was found to correlate strongly with local control at 1 year. The results were then analyzed with respect to lesion size, cutaneous versus nodal lesions, and site of cutaneous lesion (trunk, head and neck, or extremity). Correlation between fraction size and response rate was independent of lesion size, although there were fewer complete responses with increasing lesion size. Correlation was not seen in nodal lesions but was particularly striking in cutaneous lesions. This correlation was statistically significant only for cutaneous lesions of the extremities.

  6. An antiproton simulation study using MCNPX for radiation therapy.

    PubMed

    Michael Handley, Stephen; Ahmad, Salahuddin

    2011-01-01

    Radiation therapy using antiprotons is a potential interesting future modality. Energetic antiprotons penetrate matter with almost near identical stopping powers and radio biological effectiveness (RBE) as protons in the region well before the Bragg peak region. When the antiprotons come to rest at or near the Bragg peak, they annihilate releasing almost 2 GeV per annihilation. Most of the energy is carried away on the average by 4 to 5 energetic pi mesons. The annihilations lead to roughly a doubling of physical dose with additional increase due to RBE in the Bragg peak region. This study was undertaken in order to assess the effect of the products of antiproton annihilations on depth dose profiles through MCNPX simulations. Beams of protons and antiprotons with varying energies and field sizes were used in the simulations. In our study, for 126 MeV beam, the peak to entrance (P/E) dose ratios of 4.9 for protons and 8.9 for antiprotons were found which gave the antiproton/proton P/E dose ratio equals to 1.8. This is in excellent agreement with the previous result obtained with FLUKA simulations. PMID:21876284

  7. Deformation field validation and inversion applied to adaptive radiation therapy

    NASA Astrophysics Data System (ADS)

    Vercauteren, Tom; De Gersem, Werner; Olteanu, Luiza A. M.; Madani, Indira; Duprez, Fréderic; Berwouts, Dieter; Speleers, Bruno; De Neve, Wilfried

    2013-08-01

    Development and implementation of chronological and anti-chronological adaptive dose accumulation strategies in adaptive intensity-modulated radiation therapy (IMRT) for head-and-neck cancer. An algorithm based on Newton iterations was implemented to efficiently compute inverse deformation fields (DFs). Four verification steps were performed to ensure a valid dose propagation: intra-cell folding detection finds zero or negative Jacobian determinants in the input DF; inter-cell folding detection is implemented on the resolution of the output DF; a region growing algorithm detects undefined values in the output DF; DF domains can be composed and displayed on the CT data. In 2011, one patient with nonmetastatic head and neck cancer selected from a three phase adaptive DPBN study was used to illustrate the algorithms implemented for adaptive chronological and anti-chronological dose accumulation. The patient received three 18F-FDG-PET/CTs prior to each treatment phase and one CT after finalizing treatment. Contour propagation and DF generation between two consecutive CTs was performed in Atlas-based autosegmentation (ABAS). Deformable image registration based dose accumulations were performed on CT1 and CT4. Dose propagation was done using combinations of DFs or their inversions. We have implemented a chronological and anti-chronological dose accumulation algorithm based on DF inversion. Algorithms were designed and implemented to detect cell folding.

  8. Objective Assessment of Image Quality VI: Imaging in Radiation Therapy

    PubMed Central

    Barrett, Harrison H.; Kupinski, Matthew A.; Müeller, Stefan; Halpern, Howard J.; Morris, John C.; Dwyer, Roisin

    2015-01-01

    Earlier work on Objective Assessment of Image Quality (OAIQ) focused largely on estimation or classification tasks in which the desired outcome of imaging is accurate diagnosis. This paper develops a general framework for assessing imaging quality on the basis of therapeutic outcomes rather than diagnostic performance. By analogy to Receiver Operating Characteristic (ROC) curves and their variants as used in diagnostic OAIQ, the method proposed here utilizes the Therapy Operating Characteristic or TOC curves, which are plots of the probability of tumor control vs. the probability of normal-tissue complications as the overall dose level of a radiotherapy treatment is varied. The proposed figure of merit is the area under the TOC curve, denoted AUTOC. This paper reviews an earlier exposition of the theory of TOC and AUTOC, which was specific to the assessment of image-segmentation algorithms, and extends it to other applications of imaging in external-beam radiation treatment as well as in treatment with internal radioactive sources. For each application, a methodology for computing the TOC is presented. A key difference between ROC and TOC is that the latter can be defined for a single patient rather than a population of patients. PMID:24200954

  9. Nuclear data needs for radiation protection and therapy dosimetry

    SciTech Connect

    Chadwick, M.B.; DeLuca, P.M. Jr.; Haight, R.C.

    1995-12-31

    New nuclear data are required for improved neutron and proton radiotherapy treatment planning as well as future applications of high-energy particle accelerators. Modern neutron radiotherapy employs energies extending to 70 MeV, while industrial applications such as transmutation and tritium breeding may generate neutrons exceeding energies of 100 MeV. Secondary neutrons produced by advanced proton therapy facilities can have energies as high as 250 MeV. Each use requires nuclear data for transport calculations and analysis of radiation effects (dosimetry). We discuss the nuclear data needs supportive of these applications including the different information requirements. As data in this energy region are sparse and likely to remain so, advanced nuclear model calculations can provide some of the needed information. ln this context, we present new evaluated nuclear data for C, N, and O. Additional experimental information, including integral and differential data, are required to confirm these results and to bound further calculations. We indicate the required new data to be measured and the difficulties in carrying out such experiments.

  10. Radiant{trademark} Liquid Radioisotope Intravascular Radiation Therapy System

    SciTech Connect

    Eigler, N.; Whiting, J.; Chernomorsky, A.; Jackson, J.; Knapp, F.F., Jr.; Litvack, F.

    1998-01-16

    RADIANT{trademark} is manufactured by United States Surgical Corporation, Vascular Therapies Division, (formerly Progressive Angioplasty Systems). The system comprises a liquid {beta}-radiation source, a shielded isolation/transfer device (ISAT), modified over-the-wire or rapid exchange delivery balloons, and accessory kits. The liquid {beta}-source is Rhenium-188 in the form of sodium perrhenate (NaReO{sub 4}), Rhenium-188 is primarily a {beta}-emitter with a physical half-life of 17.0 hours. The maximum energy of the {beta}-particles is 2.1 MeV. The source is produced daily in the nuclear pharmacy hot lab by eluting a Tungsten-188/Rhenium-188 generator manufactured by Oak Ridge National Laboratory (ORNL). Using anion exchange columns and Millipore filters the effluent is concentrated to approximately 100 mCi/ml, calibrated, and loaded into the (ISAT) which is subsequently transported to the cardiac catheterization laboratory. The delivery catheters are modified Champion{trademark} over-the-wire, and TNT{trademark} rapid exchange stent delivery balloons. These balloons have thickened polyethylene walls to augment puncture resistance; dual radio-opaque markers and specially configured connectors.

  11. Acid ceramidase in prostate cancer radiation therapy resistance and relapse

    NASA Astrophysics Data System (ADS)

    Cheng, Joseph C.

    Prostate tumor cell escape from ionizing radiation (IR)-induced killing can lead to disease progression and relapse. Sphingolipids such as ceramide and sphingosine 1-phosphate influence signal transduction pathways that regulate stress response in cancer cells. In particular, metabolism of apoptotic ceramide constitutes an important survival adaptation. Assessments of enzyme activity, mRNA, and protein demonstrated preferential upregulation of the ceramide deacylating enzyme acid ceramidase (AC) in irradiated cancer cells. Promoter-reporter and ChIP-qPCR assays revealed AC transcription by activator protein 1 (AP-1) is sensitive to pharmacological inhibition of de novo ceramide biosynthesis, identifying a protective feedback mechanism that mitigates the effects of IR-induced ceramide. Deregulation of c-Jun, in particular, induced marked radiosensitization in vitro and in vivo, which was rescued by ectopic AC over-expression. AC over-expression in prostate cancer clonogens surviving 80 Gray fractionated irradiation was associated with increased radioresistance and proliferation, suggesting a role in radiotherapy failure and relapse. Indeed, immunohistochemical analysis of human prostate cancer tissues revealed higher levels of AC after radiotherapy failure than therapy-naive adenocarcinoma, PIN, or benign tissues. By genetically downregulating AC with small interfering RNA (siRNA), we observed radiosensitization of cells using clonogenic and cytotoxicity assays. Finally, treatment with lysosomotropic small molecule inhibitors of AC, LCL385 or LCL521, induced prostate cancer xenograft radiosensitization and long-term suppression, suggesting AC is a tractable target for adjuvant radiotherapy.

  12. High resolution optical calorimetry for synchrotron microbeam radiation therapy

    NASA Astrophysics Data System (ADS)

    Ackerly, T.; Crosbie, J. C.; Fouras, A.; Sheard, G. J.; Higgins, S.; Lewis, R. A.

    2011-03-01

    We propose the application of optical calorimetry to measure the peak to valley ratio for synchrotron microbeam radiation therapy (MRT). We use a modified Schlieren approach known as reference image topography (RIT) which enables one to obtain a map of the rate of change of the refractive index in a water bath from which the absorbed dose can be determined with sufficient spatial accuracy to determine the peak to valley ratio. We modelled the calorimetric properties of X-rays using a heated wire in a water bath. Our RIT system comprised a light source, a textured reference object and a camera and lens combination. We measured temperature contours and showed a plume rising from the heated wire. The total temperature change in water was 12 degrees C, 500 times greater than the calculated change from a 1 ms exposure on a synchrotron. At 1.0 ms, thermal diffusion will be the major cause of uncertainty in determining the peak to valley ratio, and we calculate thermal diffusion will reduce the measured peak to valley ratio to 76% of its initial value, but the individual microbeams will still resolve. We demonstrate proof of concept for measuring X-ray dose using a modified RIT method.

  13. Cherenkov Video Imaging Allows for the First Visualization of Radiation Therapy in Real Time

    SciTech Connect

    Jarvis, Lesley A.; Zhang, Rongxiao; Gladstone, David J.; Jiang, Shudong; Hitchcock, Whitney; Friedman, Oscar D.; Glaser, Adam K.; Jermyn, Michael; Pogue, Brian W.

    2014-07-01

    Purpose: To determine whether Cherenkov light imaging can visualize radiation therapy in real time during breast radiation therapy. Methods and Materials: An intensified charge-coupled device (CCD) camera was synchronized to the 3.25-μs radiation pulses of the clinical linear accelerator with the intensifier set × 100. Cherenkov images were acquired continuously (2.8 frames/s) during fractionated whole breast irradiation with each frame an accumulation of 100 radiation pulses (approximately 5 monitor units). Results: The first patient images ever created are used to illustrate that Cherenkov emission can be visualized as a video during conditions typical for breast radiation therapy, even with complex treatment plans, mixed energies, and modulated treatment fields. Images were generated correlating to the superficial dose received by the patient and potentially the location of the resulting skin reactions. Major blood vessels are visible in the image, providing the potential to use these as biological landmarks for improved geometric accuracy. The potential for this system to detect radiation therapy misadministrations, which can result from hardware malfunction or patient positioning setup errors during individual fractions, is shown. Conclusions: Cherenkoscopy is a unique method for visualizing surface dose resulting in real-time quality control. We propose that this system could detect radiation therapy errors in everyday clinical practice at a time when these errors can be corrected to result in improved safety and quality of radiation therapy.

  14. New and emerging biologic therapies for moderate-to-severe plaque psoriasis: mechanistic rationales and recent clinical data for IL-17 and IL-23 inhibitors

    PubMed Central

    Gaspari, Anthony A; Tyring, Stephen

    2015-01-01

    The development of effective and well-tolerated biologic therapies has advanced the management of psoriasis by enabling clinicians to treat underlying disease mechanisms. Biologics approved for the treatment of moderate-to-severe psoriasis include three tumor necrosis factor alpha inhibitors and an interleukin-12/interleukin-23 inhibitor. The establishment of the immunological basis of psoriasis has led to the development of biologic agents targeting specific downstream mediators in the psoriatic cascade. These drugs inhibit cytokines and cytokine signaling/transcription mediators like interleukin-17, which plays an important role in immunopathogenesis. Several interleukin-17 inhibitors are undergoing phase 3 clinical studies. In addition, biologics that selectively inhibit interleukin-23 have been assessed in phase 2 studies. This review describes how the dissection of pathways in the immunopathogenesis of psoriasis has led to the development of therapeutic agents and highlights the latest clinical efficacy, safety and tolerability data on new and emerging biologic therapies that selectively target interleukin-17 or interleukin-23. PMID:26201310

  15. Accuracy of Real-time Couch Tracking During 3-dimensional Conformal Radiation Therapy, Intensity Modulated Radiation Therapy, and Volumetric Modulated Arc Therapy for Prostate Cancer

    SciTech Connect

    Wilbert, Juergen; Baier, Kurt; Hermann, Christian; Flentje, Michael; Guckenberger, Matthias

    2013-01-01

    Purpose: To evaluate the accuracy of real-time couch tracking for prostate cancer. Methods and Materials: Intrafractional motion trajectories of 15 prostate cancer patients were the basis for this phantom study; prostate motion had been monitored with the Calypso System. An industrial robot moved a phantom along these trajectories, motion was detected via an infrared camera system, and the robotic HexaPOD couch was used for real-time counter-steering. Residual phantom motion during real-time tracking was measured with the infrared camera system. Film dosimetry was performed during delivery of 3-dimensional conformal radiation therapy (3D-CRT), step-and-shoot intensity modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT). Results: Motion of the prostate was largest in the anterior-posterior direction, with systematic ( N-Ary-Summation ) and random ({sigma}) errors of 2.3 mm and 2.9 mm, respectively; the prostate was outside a threshold of 5 mm (3D vector) for 25.0%{+-}19.8% of treatment time. Real-time tracking reduced prostate motion to N-Ary-Summation =0.01 mm and {sigma} = 0.55 mm in the anterior-posterior direction; the prostate remained within a 1-mm and 5-mm threshold for 93.9%{+-}4.6% and 99.7%{+-}0.4% of the time, respectively. Without real-time tracking, pass rates based on a {gamma} index of 2%/2 mm in film dosimetry ranged between 66% and 72% for 3D-CRT, IMRT, and VMAT, on average. Real-time tracking increased pass rates to minimum 98% on average for 3D-CRT, IMRT, and VMAT. Conclusions: Real-time couch tracking resulted in submillimeter accuracy for prostate cancer, which transferred into high dosimetric accuracy independently of whether 3D-CRT, IMRT, or VMAT was used.

  16. Optimization and quality assurance of an image-guided radiation therapy system for intensity-modulated radiation therapy radiotherapy

    SciTech Connect

    Tsai, Jen-San; Micaily, Bizhan; Miyamoto, Curtis

    2012-10-01

    To develop a quality assurance (QA) of XVI cone beam system (XVIcbs) for its optimal imaging-guided radiotherapy (IGRT) implementation, and to construe prostate tumor margin required for intensity-modulated radiation therapy (IMRT) if IGRT is unavailable. XVIcbs spatial accuracy was explored with a humanoid phantom; isodose conformity to lesion target with a rice phantom housing a soap as target; image resolution with a diagnostic phantom; and exposure validation with a Radcal ion chamber. To optimize XVIcbs, rotation flexmap on coincidency between gantry rotational axis and that of XVI cone beam scan was investigated. Theoretic correlation to image quality of XVIcbs rotational axis stability was elaborately studied. Comprehensive QA of IGRT using XVIcbs has initially been explored and then implemented on our general IMRT treatments, and on special IMRT radiotherapies such as head and neck (H and N), stereotactic radiation therapy (SRT), stereotactic radiosurgery (SRS), and stereotactic body radiotherapy (SBRT). Fifteen examples of prostate setup accounted for 350 IGRT cone beam system were analyzed. IGRT accuracy results were in agreement {+-} 1 mm. Flexmap 0.25 mm met the manufacturer's specification. Films confirmed isodose coincidence with target (soap) via XVIcbs, otherwise not. Superficial doses were measured from 7.2-2.5 cGy for anatomic diameters 15-33 cm, respectively. Image quality was susceptible to rotational stability or patient movement. IGRT using XVIcbs on general IMRT treatments such as prostate, SRT, SRS, and SBRT for setup accuracy were verified; and subsequently coordinate shifts corrections were recorded. The 350 prostate IGRT coordinate shifts modeled to Gaussian distributions show central peaks deviated off the isocenter by 0.6 {+-} 3.0 mm, 0.5 {+-} 4.5 mm in the X(RL)- and Z(SI)-coordinates, respectively; and 2.0 {+-} 3.0 mm in the Y(AP)-coordinate as a result of belly and bladder capacity variations. Sixty-eight percent of confidence was within {+-} 4.5 mm coordinates shifting. IGRT using XVIcbs is critical to IMRT for prostate and H and N, especially SRT, SRS, and SBRT. To optimize this modality of IGRT, a vigilant QA program is indispensable. Prostate IGRT reveals treatment accuracy as subject to coordinates' adjustments; otherwise a 4.5-mm margin is required to allow for full dose coverage of the clinical target volume, notwithstanding toxicity to normal tissues.

  17. Optimization and quality assurance of an image-guided radiation therapy system for intensity-modulated radiation therapy radiotherapy.

    PubMed

    Tsai, Jen-San; Micaily, Bizhan; Miyamoto, Curtis

    2012-01-01

    To develop a quality assurance (QA) of XVI cone beam system (XVIcbs) for its optimal imaging-guided radiotherapy (IGRT) implementation, and to construe prostate tumor margin required for intensity-modulated radiation therapy (IMRT) if IGRT is unavailable. XVIcbs spatial accuracy was explored with a humanoid phantom; isodose conformity to lesion target with a rice phantom housing a soap as target; image resolution with a diagnostic phantom; and exposure validation with a Radcal ion chamber. To optimize XVIcbs, rotation flexmap on coincidency between gantry rotational axis and that of XVI cone beam scan was investigated. Theoretic correlation to image quality of XVIcbs rotational axis stability was elaborately studied. Comprehensive QA of IGRT using XVIcbs has initially been explored and then implemented on our general IMRT treatments, and on special IMRT radiotherapies such as head and neck (H and N), stereotactic radiation therapy (SRT), stereotactic radiosurgery (SRS), and stereotactic body radiotherapy (SBRT). Fifteen examples of prostate setup accounted for 350 IGRT cone beam system were analyzed. IGRT accuracy results were in agreement ± 1 mm. Flexmap 0.25 mm met the manufacturer's specification. Films confirmed isodose coincidence with target (soap) via XVIcbs, otherwise not. Superficial doses were measured from 7.2-2.5 cGy for anatomic diameters 15-33 cm, respectively. Image quality was susceptible to rotational stability or patient movement. IGRT using XVIcbs on general IMRT treatments such as prostate, SRT, SRS, and SBRT for setup accuracy were verified; and subsequently coordinate shifts corrections were recorded. The 350 prostate IGRT coordinate shifts modeled to Gaussian distributions show central peaks deviated off the isocenter by 0.6 ± 3.0 mm, 0.5 ± 4.5 mm in the X(RL)- and Z(SI)-coordinates, respectively; and 2.0 ± 3.0 mm in the Y(AP)-coordinate as a result of belly and bladder capacity variations. Sixty-eight percent of confidence was within ± 4.5 mm coordinates shifting. IGRT using XVIcbs is critical to IMRT for prostate and H and N, especially SRT, SRS, and SBRT. To optimize this modality of IGRT, a vigilant QA program is indispensable. Prostate IGRT reveals treatment accuracy as subject to coordinates' adjustments; otherwise a 4.5-mm margin is required to allow for full dose coverage of the clinical target volume, notwithstanding toxicity to normal tissues. PMID:22417899

  18. Patterns of clinical care in radiation therapy in the United States

    SciTech Connect

    Kramer, S.

    1984-06-01

    Results of the first nationwide evaluation of radiation therapy in the United States with respect to its quality and accessibility are presented. The Patterns of Care Study (PCS) is financially supported by the National Cancer Institute and has served as a model for other oncology-related disciplines. The PCS has determined criteria by which to evaluate radiation therapy care in 10 disease sites in which curative radiation therapy plays a major role. The sampling design identified the institution to be surveyed and included all types of practice in the U.S. This paper examines results related to carcinomas of the cervix, larynx and prostate.

  19. Internal radiation therapy: a neglected aspect of nuclear medicine in the molecular era

    PubMed Central

    Lin, Yansong

    2015-01-01

    Abstract With increasing evidence, internal radiation therapy, also known as brachytherapy, has become a neglected aspect of nuclear medicine in the molecular era. In this paper, recent developments regarding internal radiation therapy, including developments in radioiodine-131 (131I) and thyroid, radioimmunotherapy (RIT) for non-Hodgkin lymphoma (NHL), and radiopharmaceuticals for bone metastases. Relevant differences and status of their applications in China were mentioned as well. These molecular mediated internal radiation therapies are gaining increasing importance by providing palliative and curative treatments for an increasing number of diseases and becoming one of the important parts of molecular nuclear medicine. PMID:26445567

  20. How do we prevent the vulnerable atherosclerotic plaque from rupturing? Insights from in vivo assessments of plaque, vascular remodeling, and local endothelial shear stress.

    PubMed

    Andreou, Ioannis; Antoniadis, Antonios P; Shishido, Koki; Papafaklis, Michail I; Koskinas, Konstantinos C; Chatzizisis, Yiannis S; Coskun, Ahmet U; Edelman, Elazer R; Feldman, Charles L; Stone, Peter H

    2015-05-01

    Coronary atherosclerosis progresses both as slow, gradual enlargement of focal plaque and also as a more dynamic process with periodic abrupt changes in plaque geometry, size, and morphology. Systemic vasculoprotective therapies such as statins, angiotensin-converting enzyme inhibitors, and antiplatelet agents are the cornerstone of prevention of plaque rupture and new adverse clinical outcomes, but such systemic therapies are insufficient to prevent the majority of new cardiac events. Invasive imaging methods have been able to identify both the anatomic features of high-risk plaque and the ongoing pathobiological stimuli responsible for progressive plaque inflammation and instability and may provide sufficient information to formulate preventive local mechanical strategies (eg, preemptive percutaneous coronary interventions) to avert cardiac events. Local endothelial shear stress (ESS) triggers vascular phenomena that synergistically exacerbate atherosclerosis toward an unstable phenotype. Specifically, low ESS augments lipid uptake and catabolism, induces plaque inflammation and oxidation, downregulates the production, upregulates the degradation of extracellular matrix, and increases cellular apoptosis ultimately leading to thin-cap fibroatheromas and/or endothelial erosions. Increases in blood thrombogenicity that result from either high or low ESS also contribute to plaque destabilization. An understanding of the actively evolving vascular phenomena, as well as the development of in vivo imaging methodologies to identify the presence and severity of the different processes, may enable early identification of a coronary plaque destined to acquire a high-risk state and allow for highly selective, focal preventive interventions to avert the adverse natural history of that particular plaque. In this review, we focus on the role of ESS in the pathobiologic processes responsible for plaque destabilization, leading either to accelerated plaque growth or to acute coronary events, and emphasize the potential to utilize in vivo risk stratification of individual coronary plaques to optimize prevention strategies to preclude new cardiac events. PMID:25336461