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1

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

SciTech Connect

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.

Finger, Paul T., E-mail: pfinger@eyecancer.com [New York Eye Cancer Center, New York, NY (United States); New York Eye and Ear Infirmary, New York, NY (United States); Chin, Kimberly J. [New York Eye Cancer Center, New York, NY (United States); Yu Guopei [New York Eye and Ear Infirmary, New York, NY (United States); Patel, Neil S. [New York Eye Cancer Center, New York, NY (United States); New York Eye and Ear Infirmary, New York, NY (United States)

2011-07-01

2

Multifocal iris melanoma treated with total anterior segment palladium-103 plaque radiation therapy  

Microsoft Academic Search

Background  A 73-year-old patient presented in our clinic with multiple pigmented iris nodules in the left eye. Though asymptomatic, there\\u000a was a reported increase in size and number of the nodules during the past year.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Interventional case report describing a biopsy-proven multifocal iris melanoma treated with a palladium-103 plaque to include\\u000a the entire anterior chamber within the targeted zone. Biopsy was

Vasileois Petousis; Paul T. Finger; Tatyana Milman

2011-01-01

3

[{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

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.

Finger, Paul T., E-mail: pfinger@eyecancer.co [New York Eye Cancer Center, New York City, New York (United States); Chin, Kimberly J. [New York Eye Cancer Center, New York City, New York (United States)

2011-01-01

4

Radiation therapy  

MedlinePLUS

... Because radiation is most harmful to quickly growing cells, radiation therapy damages cancer cells more than normal cells. This ... cells from growing and dividing, and leads to cell death. Radiation therapy is used to fight many types of cancer . ...

5

Dosimetric Benefit of a New Ophthalmic Radiation Plaque  

SciTech Connect

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.

Marwaha, Gaurav, E-mail: marwahg2@ccf.org [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Wilkinson, Allan [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Bena, James [Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Macklis, Roger [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Singh, Arun D. [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States) [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States)

2012-12-01

6

Radiation Therapy  

MedlinePLUS

... the radiation treatment, he or she marks it with ink. This "tattoo" should not be wiped off because these spots ... throat can get sore, which can be treated with a type of mouthwash prescribed ... wear off. For a kid getting radiation therapy, it's normal to feel a ...

7

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

SciTech Connect

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.

Murakami, Naoya, E-mail: namuraka@ncc.go.jp [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)] [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Suzuki, Shigenobu [Department of Ophthalmic Oncology, National Cancer Center Hospital, Tokyo (Japan)] [Department of Ophthalmic Oncology, National Cancer Center Hospital, Tokyo (Japan); Ito, Yoshinori [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)] [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Yoshimura, Ryoichi [Department of Diagnostic Radiology and Oncology, Head and Neck Reconstruction Division, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan)] [Department of Diagnostic Radiology and Oncology, Head and Neck Reconstruction Division, Graduate School, Tokyo Medical and Dental University, Tokyo (Japan); Inaba, Koji; Kuroda, Yuki; Morota, Madoka; Mayahara, Hiroshi; Sakudo, Mototake; Wakita, Akihisa; Okamoto, Hiroyuki; Sumi, Minako; Kagami, Yoshikazu [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)] [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan); Nakagawa, Keiichi; Ohtomo, Kuni [Department of Radiology, University of Tokyo Hospital, Tokyo (Japan)] [Department of Radiology, University of Tokyo Hospital, Tokyo (Japan); Itami, Jun [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)] [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)

2012-09-01

8

Identifying Vulnerable Plaques with Acoustic Radiation Force Impulse Imaging  

NASA Astrophysics Data System (ADS)

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.

Doherty, Joshua Ryan

9

Detection and photodynamic therapy of inflamed atherosclerotic plaques in the carotid artery of rabbits  

E-print Network

Detection and photodynamic therapy of inflamed atherosclerotic plaques in the carotid artery Keywords: Atherosclerosis Vulnerable plaque Macrophage Fluorescence intensity Photodynamic therapy a b s t r a c t Photodynamic therapy (PDT) has been applied in the treatment of artery restenosis following

Cao, Wenwu

10

Radiation Therapy  

MedlinePLUS

... therapy. A machine referred to as a linear accelerator is used to direct high-energy rays at the cancer delivered through the skin. The linear accelerator is located outside body and does not touch ...

11

Radiation related complications after ruthenium plaque radiotherapy of uveal melanoma.  

PubMed Central

AIMS/BACKGROUND: To analyse radiation related complications and secondary enucleation after irradiation of malignant uveal melanoma with ruthenium-106 plaques. METHODS: A series of 100 consecutive eyes irradiated in 1981-91 was analysed using the life table method and the Cox proportional hazards model. The median apical and scleral tumour dose was 100 Gy (range 15-200 Gy) and 1000 Gy (range 200-1200 Gy), respectively. The median follow up time was 2.8 and 2.0 years (range 1 month to 10 years) for anterior and posterior segment complications, respectively. RESULTS: The 3 and 5 year probabilities of being without radiation cataract were 73% and 63%, without neovascular glaucoma 91% and 81%, without vitreous haemorrhage 83% and 74%, without radiation maculopathy 85% and 70%, and without radiation optic neuropathy 90% and 88%, respectively. The risk of radiation cataract was highest with large tumour size (T1 + T2 v T3, p = 0.0027; height < or = 5 v > 5 mm, p = 0.029; largest basal diameter (LBD) < or = 15 v > 15 mm, p < 0.0001) and location of anterior tumour margin anterior v posterior to the equator (p = 0.0003); the risk of neovascular glaucoma with large size (T1 + T2 v T3, p = 0.039; LBD < or = 15 mm v 15 mm, p = 0.021); and the risk of maculopathy and optic neuropathy with proximity of the posterior tumour margin to the fovea and the optic disc (< or = 1.5 v > 1.5 mm; p = 0.030 and p = 0.0004, respectively). In Cox's multivariate analysis the strongest risk indicator for radiation cataract (RR 1.5, 95% CI 1.4-1.6) and vitreous haemorrhage (RR 1.6, 95% CI 1.4-1.8) was the height of the tumour; for neovascular glaucoma the TNM class (RR 6.2, 95% CI 2.7-13.8); for radiation maculopathy location of posterior tumour margin within 2 mm from the fovea (RR 3.4, 95% CI 2.0-6.0); and for radiation optic neuropathy location of tumour margin within 1 DD of the optic disc (RR 6.1, 95% CI 3.0-12.4). The 3 and 5 year probabilities of avoiding enucleation were 92% and 85%, respectively. Ten eyes were enucleated--six because of recurrent tumour growth, three because of treatment complications, and one because of mistakenly suspected extraocular growth. CONCLUSION: The results suggest that the frequency of radiation related complications after ruthenium brachytherapy of uveal melanoma is acceptable, in particular as regard irradiation of small and medium sized tumours for which ruthenium therapy generally is recommended. PMID:8949719

Summanen, P; Immonen, I; Kivela, T; Tommila, P; Heikkonen, J; Tarkkanen, A

1996-01-01

12

Radiation Therapy  

MedlinePLUS

Donate Donate One Time Monthly Event Tribute For brain tumor information and support Call: 800-886-ABTA (2282) ... Donate Now Menu Treatment & Care Continuum of Care Brain Tumor Treatments Steroids Surgery Chemotherapy Radiation Stereotactic Radiosurgery Proton ...

13

Association of statin therapy with reduced coronary plaque rupture: an optical coherence tomography study  

PubMed Central

Objective Statin therapy induces plaque regression and may stabilize atheromatous plaques. Optical coherence tomography (OCT) is a high-resolution in-vivo imaging modality that allows characterization of atherosclerotic plaques. We aimed to demonstrate the potential utility of OCT in evaluating coronary plaques in patients with or without statin therapy. Methods Patients undergoing cardiac catheterization were enrolled. We identified culprit lesions and performed intracoronary OCT imaging. Plaque lipid pool, fibrous cap thickness, and frequency of thin-cap fibroatheroma were evaluated using previously validated criteria. Macrophage density was determined from optical signals within fibrous caps. Presence of calcification, thrombosis, and rupture was assessed. Results Forty-eight patients were included (26 on statins, 22 without statins). Baseline characteristics were similar apart from lipid profile. Patients on statin therapy had lower total and low-density lipoprotein cholesterol concentrations (4.45± 1.35 vs. 5.26 ± 0.83 mmol/l, P = 0.02; 2.23 ± 0.78 vs. 3.26 ±0.62 mmol/l, P < 0.001, respectively). Frequencies of lipid-rich plaque (69 vs. 82%), thin-cap fibroatheroma (31 vs. 50%), plaque calcification (15 vs. 5%) and thrombosis (15 vs. 32%), and fibrous cap macrophage density were comparable between statin and nonstatin groups (5.9 vs. 6.3%; all P =NS). Ruptured plaques were, however, significantly less frequent in patients on established statin therapy (8 vs. 36%; P = 0.03) with a trend toward increased minimum fibrous cap thickness (78 vs. 49 ?m; P = 0.07). Conclusion We demonstrated the use of OCT in plaque characterization and found that patients on prior statin therapy have reduced incidence of ruptured plaques and a trend toward thicker fibrous caps. This suggests that statins may stabilize coronary plaques. PMID:18480667

Chia, Stanley; Raffel, Owen Christopher; Takano, Masamichi; Tearney, Guillermo J.; Bouma, Brett E.; Jang, Ik-Kyung

2009-01-01

14

Gallbladder Cancer: Radiation Therapy  

MedlinePLUS

... reducing side effects. Three-dimensional conformal radiation therapy (3D-CRT): 3D-CRT is a type of external beam radiation ... therapy (IMRT) : IMRT is an advanced form of 3D therapy. It uses a computer-driven machine that ...

15

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

SciTech Connect

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.

Jensen, Ashley W. [Department of Radiation Oncology, Mayo Medical School, Mayo Clinic College of Medicine, Rochester, MN (United States); Petersen, Ivy A. [Division of Radiation Oncology, Mayo Clinic, Rochester, MN (United States)]. E-mail: petersen.ivy@mayo.edu; Kline, Robert W. [Division of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Stafford, Scott L. [Division of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Schomberg, Paula J. [Division of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Robertson, Dennis M. [Department of Ophthalmology, Mayo Clinic, Rochester, MN (United States)

2005-09-01

16

Rhabdomyosarcoma: Radiation Therapy  

MedlinePLUS

... they are available. Three-dimensional conformal radiation therapy (3D-CRT): 3D-CRT uses special computers to precisely map the ... therapy (IMRT): IMRT is an advanced form of 3D therapy. Along with shaping the beams and aiming ...

17

Microenvironment and Radiation Therapy  

PubMed Central

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

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

2013-01-01

18

Radiation therapy simulation workbook  

SciTech Connect

This book presents format simulation procedures for all major areas. For each site it discusses clinical setting, technique, procedure and dosimetry, and provides measurement worksheets and set-up diagram sheets. Of interest to radiation oncologists, radiation therapy technologists, residents, and students.

Mizer, S.; Scheller, R.R.; Deye, J.A.

1986-01-01

19

Stereotactic Body Radiation Therapy  

Microsoft Academic Search

\\u000a Technological advancements in imaging and radiation planning and delivery have made it possible for cranial stereotactic radiosurgery\\u000a techniques to be applied to tumors outside of the brain. Although high-dose radiation therapy may be delivered in a single\\u000a fraction, referred to as extracranial stereotactic radiosurgery (SRS), more often, high-precision radiation is delivered in\\u000a more than one fraction, leading to the field

Laura A. Dawson

20

Frequency-domain optical coherence tomographic analysis of plaque microstructures at nonculprit narrowings in patients receiving potent statin therapy.  

PubMed

Potent statin therapy has been demonstrated to reduce cardiovascular events. Although statins have been considered to stabilize atherosclerotic plaque, this effect has not been well characterized in vivo. We investigated the relation between potent statin therapy and plaque microstructures imaged by frequency-domain optical coherence tomography. Two hundred ninety nonculprit lipid plaques in 275 patients with stable coronary artery disease receiving atorvastatin or rosuvastatin were analyzed. Patients were stratified into no statin, low-, and high-dose statin groups. Plaques in the high-dose statin group demonstrated a smaller lipid arc (p = 0.02) and a greater fibrous cap thickness (p = 0.01). In patients receiving statin therapy, high-dose statin therapy was associated with a greater fibrous cap thickness in patients with smaller (148.2 ± 30.5 vs 105.3 ± 41.1 ?m, p = 0.004) but not larger lipid index (91.1 ± 32.6 vs 78.1 ± 43.3 ?m, p = 0.21). In conclusion, potent statin therapy is associated with less vulnerable plaque features on frequency-domain optical coherence tomography imaging. This finding varies according to the size of plaque lipid content, being less effective in lipid-loaded plaques. PMID:24996554

Kataoka, Yu; Puri, Rishi; Hammadah, Muhammad; Duggal, Bhanu; Uno, Kiyoko; Kapadia, Samir R; Tuzcu, E Murat; Nissen, Steven E; Nicholls, Stephen J

2014-08-15

21

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

SciTech Connect

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.

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

2003-03-01

22

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

PubMed Central

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

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

2012-01-01

23

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

PubMed

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 imaging 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 imaging are orders of magnitude lower than the stresses associated with blood pressure. PMID:23122224

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

2013-01-01

24

Manifestation of palmoplantar pustulosis during or after infliximab therapy for plaque-type psoriasis: report on five cases.  

PubMed

Infliximab is a monoclonal antibody directed against TNF-alpha. It has been approved for use in rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, psoriatic arthritis and plaque-type psoriasis. In case reports, positive effects on pustular variants of psoriasis have also been reported. However, paradoxically, manifestation of pustular psoriasis and plaque-type psoriasis has been reported in patients treated with TNF antagonists including infliximab for other indications. Here, we report on 5 patients with chronic plaque-type psoriasis who developed palmoplantar pustulosis during or after discontinuation of infliximab therapy. In two of the five cases, manifestation of palmoplantar pustulosis was not accompanied by worsening of plaque-type psoriasis. Possibly, site-specific factors or a differential contribution of immunological processes modulated by TNF inhibitors to palmoplantar pustulosis and plaque-type psoriasis may have played a role. PMID:18239925

Mössner, Rotraut; Thaci, Diamant; Mohr, Johannes; Pätzold, Sylvie; Bertsch, Hans Peter; Krüger, Ullrich; Reich, Kristian

2008-03-01

25

Manifestation of palmoplantar pustulosis during or after infliximab therapy for plaque-type psoriasis: report on five cases  

PubMed Central

Infliximab is a monoclonal antibody directed against TNF-?. It has been approved for use in rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, psoriatic arthritis and plaque-type psoriasis. In case reports, positive effects on pustular variants of psoriasis have also been reported. However, paradoxically, manifestation of pustular psoriasis and plaque-type psoriasis has been reported in patients treated with TNF antagonists including infliximab for other indications. Here, we report on 5 patients with chronic plaque-type psoriasis who developed palmoplantar pustulosis during or after discontinuation of infliximab therapy. In two of the five cases, manifestation of palmoplantar pustulosis was not accompanied by worsening of plaque-type psoriasis. Possibly, site-specific factors or a differential contribution of immunological processes modulated by TNF inhibitors to palmoplantar pustulosis and plaque-type psoriasis may have played a role. PMID:18239925

Thaci, Diamant; Mohr, Johannes; Pätzold, Sylvie; Bertsch, Hans Peter; Krüger, Ullrich; Reich, Kristian

2008-01-01

26

[Problems after radiation therapy].  

PubMed

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

Karasawa, Kumiko

2014-01-01

27

Radiation Therapy Technology Professional Curriculum  

E-print Network

Radiation Therapy Technology Professional Curriculum Fall Semester RT 3000 Concepts of Clinical Care RT 3010 Introductory Radiation Physics RT 3310 Clinical Practicum I RT 3110 Clinical Aspects of Radiation Therapy Semester Total Credits 12 Winter Semester RT 5650 Pathophysiology for Health Sciences RT

Berdichevsky, Victor

28

Radiation Therapy: Preventing and Managing Side Effects  

MedlinePLUS

... effects of radiation therapy Preventing and managing side effects of radiation therapy When the radiation damages nearby ... radiation therapy ” section for more on this. Side effects can vary. Your doctor and nurse are the ...

29

Radiation Therapy for Testicular Cancer  

MedlinePLUS

... testicular cancer Next Topic Chemotherapy for testicular cancer Radiation therapy for testicular cancer This treatment uses high- ... cells or slow their growth. In testicular cancer, radiation is mainly used to kill cancer cells that ...

30

Supportive therapy in radiation oncology.  

PubMed

Measures for supportive care of the radiation therapy patient are presented. These include emotional support prior to and during the course of therapy facilitated by a written interview that allows the radiation oncologist to be a supportive communicator of realistic information. A discussion is made of the support of body tissues affected by combination radiation and chemotherapy. These tissues usually include skin, oral, esophageal and intestinal mucosa, and teeth. Means of maintaining nutritional support following weight loss of patients during therapy are described. PMID:402193

Rotman, M; Rogow, L; DeLeon, G; Heskel, N

1977-02-01

31

Radiation Therapy Side Effects Sheets  

Cancer.gov

Radiation therapy fact sheets that help patients understand their treatment and manage side effects. The fact sheets (also available in audio) have tips from patients and healthcare providers, and questions to ask providers.

32

[Guidelines for high-quality use of biologic therapies in adults with plaque psoriasis].  

PubMed

Psoriasis is an inflammatory dermatosis, affecting approximately 2% of the population, with predominantly skin and joint involvement but also associated with considerable comorbidities. Approximately 20% to 30% of patients have moderate to severe disease uncontrollable with topical therapy. Traditional systemic therapy – oral PUVA, retinoids, cyclosporin and methotrexate – may induce organ specific toxicity and a significant number of patients are unresponsive, intolerant or have specific contraindications to its use. With the increased understanding of the pathogenesis of psoriasis, multiple biologic agents have been introduced. In the last years there has been an increased utilization of these agents and several studies were designed to evaluate their efficacy and safety. Currently, four biologics have been already approved by EMEA (European Medicines Agency) for the treatment of plaque psoriasis, 3 anti-TNF? (adalimumab, etanercept and infliximab) and one anti-IL12/23p40 (ustecinumab). In the present article we update the prior published guidelines (Trabalhos da SPDV 2010;68(1):47-68 and 2011;69(4):531-553) due to the recent progress in the knowledge and therapeutic options in these area. These recommendations should be used with caution and treatment should be tailored to meet individual patient's needs and each specific clinical situation. PMID:22985925

Marques Pinto, Gabriela; Filipe, Paulo

2012-01-01

33

Advances in radiation therapy dosimetry  

PubMed Central

During the last decade, there has been an explosion of new radiation therapy planning and delivery tools. We went through a rapid transition from conventional three-dimensional (3D) conformal radiation therapy to intensity-modulated radiation therapy (IMRT) treatments, and additional new techniques for motion-adaptive radiation therapy are being introduced. These advances push the frontiers in our effort to provide better patient care; and with the addition of IMRT, temporal dimensions are major challenges for the radiotherapy patient dosimetry and delivery verification. Advanced techniques are less tolerant to poor implementation than are standard techniques. Mis-administrations are more difficult to detect and can possibly lead to poor outcomes for some patients. Instead of presenting a manual on quality assurance for radiation therapy, this manuscript provides an overview of dosimetry verification tools and a focused discussion on breath holding, respiratory gating and the applications of four-dimensional computed tomography in motion management. Some of the major challenges in the above areas are discussed. PMID:20098555

Paliwal, Bhudatt; Tewatia, Dinesh

2009-01-01

34

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

SciTech Connect

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.

Yousef, Yacoub A. [New York Eye Cancer Center, New York Eye and Ear Infirmary, and New York University School of Medicine, New York, NY (United States); Finger, Paul T., E-mail: pfinger@eyecancer.com [New York Eye Cancer Center, New York Eye and Ear Infirmary, and New York University School of Medicine, New York, NY (United States)

2012-07-15

35

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. ...

36

Radiation therapy - skin care  

MedlinePLUS

... not swim in pools, salt water, lakes, or ponds. Keep the treatment area out of direct sun ... Czito BG, Willett CG. Radiation injury. In: Feldman M, Friedman LS, ... Liver Disease . 9th ed. Philadelphia, PA: Saunders Elsevier; 2010: ...

37

Conformal Radiation Therapy for Childhood CNS Tumors  

Microsoft Academic Search

Radiation therapy plays a central role in the man- agement of many childhood brain tumors. By combin- ing advances in brain tumor imaging with technology to plan and deliver radiation therapy, pediatric brain tumors can be treated with conformal radiation ther- apy. Through conformal radiation therapy, the radia- tion dose is targeted to the tumor, which can minimize the dose

DAVID G. KIRSCH; NANCY J. TARBELL

38

Oral complications in radiation therapy.  

PubMed

The dentist is integral to managing care for patients with head and neck cancer. Oral complications may manifest during and/or following radiation therapy and can last for the lifetime of the individual. This article reviews a number of these complications as well as the resources available to dentists for managing care of radiation oncology patients and improving their quality of life. PMID:15055655

Harrison, Jody S; Dale, Robert A; Haveman, Carl W; Redding, Spencer W

2003-01-01

39

Radiation Therapy (For Parents)  

MedlinePLUS

... may have some restrictions. The radiation in the implant may send high-energy rays outside the patient's body, so visitors must be protected from exposure. The child will be in a private room, and nurses and visitors can enter only for short periods of time. The child will have all ...

40

Radiation Therapy for Skin Cancer  

MedlinePLUS

... Other common treatments include surgery, chemotherapy and cryosurgery. Squamous cell carcinoma:This is the second most common type of skin cancer. These cancers also begin in the epidermis. Radiation therapy can be used to treat squamous cell cancers that start on the skin and ...

41

Radiation Therapy for Breast Cancer  

MedlinePLUS

RADIATION THERAPY FOR BREAST CANCER © ASTRO 2011 Printed on Recycled Paper CARING FOR YOURSELF NOTES/QUESTIONS FOR YOUR DOCTOR Facts to Help Patients Make ... Oncology Group www.rtog.org HELPFUL WEBSITES ON BREAST CANCER Breast Cancer Network of Strength www.networkofstrength.org ...

42

Cancer Treatment with Gene Therapy and Radiation Therapy  

PubMed Central

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

Kaliberov, Sergey A.; Buchsbaum, Donald J.

2013-01-01

43

Carotid plaque regression following 6-month statin therapy assessed by 3T cardiovascular magnetic resonance: comparison with ultrasound intima media thickness  

PubMed Central

Background Cardiovascular magnetic resonance (CMR) allows volumetric carotid plaque measurement that has advantage over 2-dimensional ultrasound (US) intima-media thickness (IMT) in evaluating treatment response. We tested the hypothesis that 6-month statin treatment in patients with carotid plaque will lead to plaque regression when measured by 3 Tesla CMR but not by IMT. Methods Twenty-six subjects (67 ± 2 years, 7 females) with known carotid plaque (> 1.1 mm) and coronary or cerebrovascular atherosclerotic disease underwent 3T CMR (T1, T2, proton density and time of flight sequences) and US at baseline and following 6 months of statin therapy (6 had initiation, 7 had increase and 13 had maintenance of statin dosing). CMR plaque volume (PV) was measured in the region 12 mm below and up to 12 mm above carotid flow divider using software. Mean posterior IMT in the same region was measured. Baseline and 6-month CMR PV and US IMT were compared. Change in lipid rich/necrotic core (LR/NC) and calcification plaque components from CMR were related to change in PV. Results Low-density lipoprotein cholesterol decreased (86 ± 6 to 74 ± 4 mg/dL, p = 0.046). CMR PV decreased 5.8 ± 2% (1036 ± 59 to 976 ± 65 mm3, p = 0.018). Mean IMT was unchanged (1.12 ± 0.06 vs. 1.14 ± 0.06 mm, p = NS). Patients with initiation or increase of statins had -8.8 ± 2.8% PV change (p = 0.001) while patients with maintenance of statin dosing had -2.7 ± 3% change in PV (p = NS). There was circumferential heterogeneity in CMR plaque thickness with greatest thickness in the posterior carotid artery, in the region opposite the flow divider. Similarly there was circumferential regional difference in change of plaque thickness with significant plaque regression in the anterior carotid region in region of the flow divider. Change in LR/NC (R = 0.62, p = 0.006) and calcification (R = 0.45, p = 0.03) correlated with PV change. Conclusions Six month statin therapy in patients with carotid plaque led to reduced plaque volume by 3T CMR, but ultrasound posterior IMT did not show any change. The heterogeneous spatial distribution of plaque and regional differences in magnitude of plaque regression may explain the difference in findings and support volumetric measurement of plaque. 3T CMR has potential advantage over ultrasound IMT to assess treatment response in individuals and may allow reduced sample size, duration and cost of clinical trials of plaque regression. PMID:21812992

2011-01-01

44

Pulp innervation after radiation therapy  

SciTech Connect

Decreased sensitivity was observed in teeth within and adjacent to an irradiated field. Mandibular teeth outside the field and distal to the irradiated mandibular nerve trunk showed an immediate decrease in sensitivity, Maxillary teeth outside the field showed a delayed decrease in sensitivity. Blood flow rates and nutrition were also related to time. Neurons are though to be relatively radio-resistant and few changes were seen histologically after radiation therapy. However, functional impairment was observed in histologically normal tissue.

Knowles, J.C.; Chalian, V.A.; Shidnia, H.

1986-12-01

45

Radiation Therapy in Prostate Cancer  

Microsoft Academic Search

Adenocarcinoma of the prostate is one of the most frequently diagnosed cancers of men in the Western hemisphere and is second\\u000a only to lung cancer for male cancer mortality. Most patients are diagnosed in the early\\/clinically localized stage, which\\u000a can be treated curatively with radiation therapy alone. Innovative methods such as brachytherapy, three-dimensional conformal\\u000a radiotherapy (3D-CRT), and IMRT (intensity modulated

Moshe E. Stein; Dirk Boehmer; Abraham Kuten

46

Proton beams in radiation therapy.  

PubMed

The rationale for study of proton radiation therapy is that, for some anatomic sites and tumors, the treatment volume is smaller; i.e., there is less irradiation of nontarget tissue while the target is included in three dimensions at each treatment session. As a result, the dose to the target can be raised. The consequence is that the tumor control probability improves and the frequency and severity of treatment-related morbidity decrease. These results come about from the physical fact that the proton range in tissue is finite; in comparison, absorption of photons is an exponential function and, hence, some dose is received for the full-beam path through the body. Accordingly, the dose deep to the target for proton treatments can be zero for each beam path. This situation provides a virtually certain means of improving the treatment outcome for selected categories of patients. Experience to date with proton radiation therapy has been quite limited. As of June 1991, the total number of proton radiation-treated patients was 11,763 from the various centers. Of that number, approximately 46% and 32% have been treated for small benign intracranial lesions (principally pituitary adenomas and arteriovenous malformations) and for tumors of the eye, respectively. Thus, only some 2500 patients have been treated for all other tumor types. The results from three centers and approximately 2800 patients with uveal melanoma are that the local control rate was 96% (for failures in-field, marginal, and in other parts of the eye). The local control results for chondrosarcomas and chordomas of the skull base are 91% and 65%, respectively. These percentages compare with some 35% achieved with conventional treatment. Experience with arteriovenous malformations indicates that control of bleeding and disappearance of the lesion are comparable to those achieved by other procedures. The developments from the proton therapy programs have contributed greatly to radiation treatment planning, e.g., the first three-dimensional treatment planning system put into regular clinical use (uveal melanoma), beam's eye view, digital-reconstructed radiograph, dose-volume histograms, and definitions of the uncertainty in dose around any defined point. The potential for clinical gains is high. In May 1991, the Proton Radiation Oncology Group was formed to design, supervise, and coordinate clinical trials and to assist in data analysis. The efficacy of proton radiation therapy will be compared with that of photon therapy of the very highest technology. PMID:1311773

Suit, H; Urie, M

1992-02-01

47

Clinical and Capillaroscopic Modifications of the Psoriatic Plaque during Therapy: Observations with Oral Acitretin  

PubMed Central

Psoriasis is considered to be an inflammatory autoimmune disease, where angiogenesis plays an undefined pathogenetic role. The well-known changes of the superficial microvasculature in the psoriatic plaque can be easily assessed in vivo by videocapillaroscopy. In the last years, several studies reported the clinical and capillaroscopic response of the psoriatic plaque during different topical and systemic treatments. In the present work we evaluated the effects of acitretin (0.8?mg/kg/day) on videocapillaroscopic alterations and the clinical response in 11 patients affected by plaque psoriasis at the baseline (T0) and after 4 (T1), 8 (T2), and 12 (T3) weeks. A clinical improvement during the treatment with a complete clinical healing of the plaque in 7 of the 11 patients was observed. The typical “basket-weave” capillaries of the psoriatic lesions showed a reduction of 65.4% in diameter at the end of the study; only 3 patients returned to a normal capillaroscopic pattern. As observed during previous our studies, we found a discrepancy between clinical and capillaroscopic results, with a far greater improvement in the first than in the second. This finding could be in agreement with a secondary role of blood vessels in the pathogenesis and persistence of psoriatic lesions. PMID:24174931

Buligan, Cinzia; Errichetti, Enzo; Valent, Francesca

2013-01-01

48

Complications of intraoperative radiation therapy  

SciTech Connect

The authors have studied the severe complications occurring after treatment with intraoperative radiation therapy (IORT) in patients with locally advanced carcinoma of the rectum. Four groups of patients were compared: Group 1 (80 patients) had treatment with surgery alone for mobile and resectable tumors; Group 2 (23 patients) had treatment with high dose preoperative irradiation followed by surgical resection for tumors which were fixed to adjacent structures and initially unresectable for cure; Group 3 (24 patients, primary disease) and Group 4 (17 patients, locally recurrent disease) had locally advance tumors as in Group 2 but were treated with IORT after preoperative irradiation and attempted surgical resection. All but 3 complications occurred within one year of therapy. Severe complications were seen in 16% of patients in Group 1, 35% in Group 2, 21% in Group 3 and 47% in Group 4 (32% in Groups 3 and 4 combined).

Tepper, J.E.; Gunderson, L.L.; Orlow, E.; Cohen, A.M.; Hedberg, S.E.; Shipley, W.U.; Blitzer, P.H.; Rich, T.

1984-10-01

49

Quality assurance in radiation therapy: physics efforts  

Microsoft Academic Search

During the last two years, several important documents on quality assurance in radiation therapy have been published. In l981 the Committee on Radiation Oncology Studies, in a report to the Director of the National Cancer Institute, outlined criteria for multidisciplinary cancer management, including technical standards in radiation therapy. In March 1983, a task group of the American Association of Physicists

Göran K. Svensson

1984-01-01

50

Intensity modulated radiation therapy treatment plan optimization  

Microsoft Academic Search

In this paper, we provide an overview of the state-of-the-art of optimization models for static radiation therapy treatment\\u000a planning, focusing in particular on intensity modulated radiation therapy (IMRT) by (i) establishing a novel connection between\\u000a risk management and radiation therapy treatment planning, and (ii) unifying and contrasting two different modeling approaches.\\u000a In addition, we discussion recent and ongoing technological developments

H. Edwin Romeijn; James F. Dempsey

2008-01-01

51

Bile Duct (Cholangiocarcinoma) Cancer: Radiation Therapy  

MedlinePLUS

... reducing side effects. Three-dimensional conformal radiation therapy (3D-CRT) uses special computers to precisely map the ... Most doctors now recommend using some form of 3D-CRT when it is available. Intensity-modulated radiation ...

52

A Radiation Therapy Venipuncture Certification Education Program  

Microsoft Academic Search

The Tom Baker Cancer Center (TBCC) is located in Calgary, Alberta, and employs 80 radiation therapists. The province of Alberta currently has two facilities that offer radiation therapy services. In 2006–2007, approximately 2,800 new and repeat patients received care at the TBCC. The Radiation Treatment Program (RTP) annually performs between 220 and 240 intravenous procedures using contrast media. Radiation therapists

Katherine Jensen; Yvette Bayliss

2008-01-01

53

Characterization of a soft x-ray source for intravascular radiation therapy  

Microsoft Academic Search

Purpose: A soft X-ray device for intravascular radiation therapy of restenosis is characterized in terms of dose delivery for several artery configurations, including arteries with implanted stents, calcified plaque, and noncentered sources.Methods and Materials: The Monte Carlo code MCNP4B was used to determine the X-ray fluence and energy spectra for 15, 20, and 30-kV X-ray source generating voltages. Dose as

David P Gierga; Ruth E Shefer

2001-01-01

54

Reproducibility of coronary plaque detection and characterization using low radiation dose coronary computed tomographic angiography in patients with intermediate likelihood of coronary artery disease (ReSCAN study).  

PubMed

The purpose of this study is to evaluate the interscan, interobserver and intraobserver agreement for coronary plaque detection, and characterization using low radiation dose high-pitch spiral acquisition coronary CT angiography (CTA). Two experienced observers independently evaluated coronary CTA datasets from 50 consecutive patients undergoing two 128-slice dual source CT scans within 12 days. Mean (±SD) estimated radiation exposure was 1.5 ± 0.2 mSv per scan. Observers recorded the presence and characterization of coronary plaques as non-calcified or calcified. A "segment involvement score" (SIS) was computed by summing the numbers of segments with any coronary plaque per patient. Reproducibility was assessed using kappa (?) statistics, paired t test and Bland-Altman analyses. Interscan, interobserver, and intraobserver agreement (?-values) for detection of any or calcified plaques were 83-94% (?-values 0.57-0.85), and 67-84% (0.31-0.67) for non-calcified plaques on a patient level. No significant difference was observed in mean interscan or interobserver SIS. Mean (95% CI) intraobserver SIS difference was -0.88 (-1.25; -0.51), P < 0.001, with limits of agreement from -4.7 to 2.9. Low radiation dose high-pitch coronary CTA permits detection of any or calcified plaques with high interscan, interobserver, intraobserver agreement. However, variability for the detection of non-calcified plaque is substantial. PMID:21626043

Øvrehus, Kristian Altern; Marwan, Mohamed; Bøtker, Hans Erik; Achenbach, Stephan; Nørgaard, Bjarne Linde

2012-04-01

55

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

SciTech Connect

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.

Finger, Paul T., E-mail: pfinger@eyecancer.com [New York Eye Cancer Center, New York, NY (United States); Chin, Kimberly J. [New York Eye Cancer Center, New York, NY (United States)

2012-02-01

56

Discipline of Radiation Therapy Trinity College Dublin  

E-print Network

.10-13.40: Spoken word: Lia Mills, Author Demonstrations on thermoplastic mask production for head and neckDiscipline of Radiation Therapy Trinity College Dublin Presents: A Patient-Centred exhibition and public outreach event about radiation therapy treatment for cancer Venue: Science Gallery Trinity College

O'Mahony, Donal E.

57

Cutaneous lymphoid hyperplasia: results of radiation therapy  

SciTech Connect

Four cases of cutaneous lymphoid hyperplasia (CLH) were treated with radiation therapy. Sixteen separate areas of the skin were irradiated. Only two received more than 18 Gy (1800 rad). Follow-up ranged from eight months to seven years. No infield recurrences were observed, and cosmetic results were excellent. The authors suggest that radiation therapy can be highly effective in the treatment of CLH.

Olson, L.E.; Wilson, J.F.; Cox, J.D.

1985-05-01

58

Recent advances in light ion radiation therapy  

Microsoft Academic Search

BackgroundThe fast development of energy- and intensity-modulated radiation therapy during the last two decades using photon and electron beams has when implemented resulted in a considerable improvement of radiation therapy, particularly if combined with radiobiologically based treatment optimization techniques. This has made intensity-modulated electron and photon beams as powerful as today's uniform dose proton therapy. To be able to cure

Anders Brahme

2004-01-01

59

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Radiation therapy simulation system. 892.5840 Section 892... § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic...

2010-04-01

60

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Radiation therapy simulation system. 892.5840 Section 892... § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic...

2013-04-01

61

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Radiation therapy simulation system. 892.5840 Section 892... § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic...

2011-04-01

62

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Radiation therapy simulation system. 892.5840 Section 892... § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic...

2012-04-01

63

Radiation therapy among A-bomb survivors.  

PubMed Central

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

Russell, W J; Antoku, S

1976-01-01

64

Radiation therapy for arteriovenous malformations: a review.  

PubMed

There have been numerous case reports and series of patients treated with partial brain irradiation, linear accelerator-based radiosurgery, gamma knife radiosurgery, and Bragg peak therapy for inoperable arteriovenous malformations (AVMs). These cases are summarized and compared. There is convincing evidence that radiation therapy does have a role in obliterating carefully chosen inoperable lesions. The changes that occur in vessel walls after radiation are reviewed. Data about x-ray and gamma radiation are mostly historical and difficult to evaluate because of the techniques of partial brain irradiation. There is a lack of data about the volume of AVM treated and the minimum dose delivered to the AVM nidus. For gamma knife, heavy particle, and linear accelerator therapy, more complete data are available. The incidence of hemorrhage during the first 2 years after treatment, when radiation-induced vascular changes are proposed to occur, is approximately 2.6% per year for gamma knife therapy, 2% per year for proton beam therapy, 2.3% per year for helium beam therapy, and 2.3% per year for linear accelerator therapy. These rates are similar to the recurrence rate for hemorrhage of 2.2 to 3% per year expected based on the natural history of untreated AVMs. If AVM obliteration after therapy is not achieved, the incidence of recurrent hemorrhage remains between 2% per year after treatment with gamma knife therapy. The incidence of hemorrhage for all patients treated was reported as 0.15% per year in one study and 20% over 8 years in a follow-up study using proton beam therapy. Mortality from hemorrhage after treatment was 0.6% after gamma knife therapy, 2.3% after helium beam therapy, and 2 to 5% after proton beam therapy. These figures for mortality are all lower than the 11% observed for the natural history of untreated AVMs. Permanent neurological deficits experienced as a complication of radiation occurred in 2 to 3% of patients treated with gamma knife therapy, 4% of patients treated with helium beam therapy, 1.7% of patients treated with proton beam therapy, and 3% of patients treated with stereotactic linear accelerator therapy. Proton beam therapy has been used for both small and large lesions. The majority of lesions in patients treated with gamma knife, helium beam, and linear accelerator therapy have been small (usually less than 3.0 cm average diameter) lesions. In these patients with small inoperable lesions treated with accurately directed fields of isocentric radiation, the greatest incidence of AVM obliteration has been observed on follow-up angiograms.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2191236

Ogilvy, C S

1990-05-01

65

[Image guided radiation therapy (IGRT)].  

PubMed

Image guided radiation therapy (IGRT) is a major technical innovation of radiotherapy. It allows locating the tumor under the linear accelerator just before the irradiation, by direct visualization (3D mode soft tissue) or indirect visualization (2D mode and radio-opaque markers). The technical implementation of IGRT is done by very different complex devices. The most common modality, because available in any new accelerator, is the cone beam CT. The main experiment of IGRT focuses on prostate cancer. Preliminary studies suggest the use of IGRT combined with IMRT should increase local control and decrease toxicity, especially rectal toxicity. In head and neck tumors, due to major deformation, a rigid registration is insufficient and replanning is necessary (adaptive radiotherapy). The onboard imaging delivers a specific dose, needed to be measured and taken into account, in order not to increase the risk of toxicity. Studies comparing different modalities of IGRT according to clinical and economic endpoints are ongoing; to better define the therapeutic indications. PMID:20581000

Lagrange, J-L; de Crevoisier, R

2010-07-01

66

Managing the adverse effects of radiation therapy.  

PubMed

Nearly two thirds of patients with cancer will undergo radiation therapy as part of their treatment plan. Given the increased use of radiation therapy and the growing number of cancer survivors, family physicians will increasingly care for patients experiencing adverse effects of radiation. Selective serotonin reuptake inhibitors have been shown to significantly improve symptoms of depression in patients undergoing chemotherapy, although they have little effect on cancer-related fatigue. Radiation dermatitis is treated with topical steroids and emollient creams. Skin washing with a mild, unscented soap is acceptable. Cardiovascular disease is a well-established adverse effect in patients receiving radiation therapy, although there are no consensus recommendations for cardiovascular screening in this population. Radiation pneumonitis is treated with oral prednisone and pentoxifylline. Radiation esophagitis is treated with dietary modification, proton pump inhibitors, promotility agents, and viscous lidocaine. Radiation-induced emesis is ameliorated with 5-hydroxytryptamine3 receptor antagonists and steroids. Symptomatic treatments for chronic radiation cystitis include anticholinergic agents and phenazopyridine. Sexual dysfunction from radiation therapy includes erectile dysfunction and vaginal stenosis, which are treated with phosphodiesterase type 5 inhibitors and vaginal dilators, respectively. PMID:20704169

Berkey, Franklin J

2010-08-15

67

Biomarkers of plaque instability.  

PubMed

Atherosclerosis is the proximate cause of arterial thrombosis, leading to acute occlusive cardiovascular syndromes. Thrombosis in atherosclerosis usually results from rupture of the fibrous cap of atherosclerotic plaques with a smaller proportion resulting from superficial endothelial erosion. Ruptured plaques are often associated with intimal and adventitial inflammation, increased size of lipid-rich necrotic core with thinned out collagen-depleted fibrous cap, outward remodeling, increased plaque neovascularity, intraplaque hemorrhage, and microcalcification. By inference, non-ruptured plaques with similar compositional features are considered to be at risk for rupture and hence are labeled vulnerable plaques or high-risk plaques. Identification of vulnerable plaques may help in predicting the risk of acute occlusive syndromes and may also allow targeting for aggressive systemic and possibly local therapies. Plaque rupture is believed to result from extracellular matrix (which comprises the protective fibrous cap) dysregulation due to excessive proteolysis in the context of diminished matrix synthesis. Inflammation is believed to play a key role by providing matrix-degrading metalloproteinases and also by inducing death of matrix-synthesizing smooth muscle cells. Systemic markers of inflammation are thus the most logical forms of potential biomarkers which may predict the presence of vulnerable or high-risk plaques. Several studies have suggested the potential prognostic value of a variety of systemic markers, but regrettably, their overall clinical predictive value is modestly incremental at best, especially for individual subjects compared to groups of patients. Nevertheless, continued investigation of reliable, cost-effective biomarkers that predict the presence of a high-risk plaque and future athero-thrombotic cardiovascular events with greater sensitivity and specificity is warranted. PMID:25326730

Shah, P K

2014-12-01

68

Hyperbaric oxygen therapy for radiation myelitis  

SciTech Connect

Radiation therapy may damage healthy tissues adjacent to tumor. Hyperbaric oxygen therapy (HBO) is useful in treating soft tissue and osteoradionecrosis. In addition, HBO has been recommended to treat radiation-induced myelitis. We used radiation to induce a predictable myelitis in the spinal cords of rats who were randomized into treatment (HBO) and control groups 8 wk after irradiation. Serial neurologic examination showed no benefit or harm as a result of HBO. This small pilot study did not demonstrate any clinically significant benefit of HBO for radiation myelitis in rats.

Poulton, T.J.; Witcofski, R.L.

1985-12-01

69

Hypofractionation in radiation therapy and its impact  

SciTech Connect

A brief history of the underlying principles of the conventional fractionation in radiation therapy is discussed, followed by the formulation of the hypothesis for hypofractionated stereotactic body radiation therapy (SBRT). Subsequently, consequences of the hypothesis for SBRT dose shaping and dose delivery techniques are sketched. A brief review of the advantages of SBRT therapy in light of the existing experience is then provided. Finally, the need for new technological developments is advocated to make SBRT therapies more practical, safer, and clinically more effective. It is finally concluded that hypofractionated SBRT treatment will develop into a new paradigm that will shape the future of radiation therapy by providing the means to suppress the growth of most carcinogen-induced carcinomas and by supporting the cure of the disease.

Papiez, Lech; Timmerman, Robert [University of Texas Southwestern Medical Center, Dallas, Texas 75390 (United States)

2008-01-15

70

Radiation Sensitization in Cancer Therapy.  

ERIC Educational Resources Information Center

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,…

Greenstock, Clive L.

1981-01-01

71

New visualizations for radiation therapy treatment planning  

NASA Astrophysics Data System (ADS)

Two new interactive visualizations, currently named 'computed fluoroscopy' and 'computed Polaroids' have been added to our 3D radiation therapy treatment planning system. Our preliminary experience with these visualizations suggests that they are of real clinical value.

Rosenman, Julian G.; Cullip, Tim; Soltys, Mitchell

1994-09-01

72

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

NASA Astrophysics Data System (ADS)

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.

Daudon, M.; Bazin, D.

2013-03-01

73

Radiologist, computed tomography, and radiation therapy  

SciTech Connect

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.

Goitein, M.; Meyer, J.

1982-06-01

74

New therapeutic strategies in radiation therapy  

SciTech Connect

Radiation therapy has been an integral part of curative cancer therapy for many decades. The tolerance of normal tissues traversed by radiation and resistant tumor cell populations traditionally have limited the radiocurability of certain tumors, especially with higher clinical stages. However, research in radiobiology and radiation physics is providing ways to increase cure while limiting morbidity. Computer-controlled dynamic treatment, radioprotector drugs, hyperbaric oxygen, carbogen breathing during irradiation, particle irradiation, and hypoxic cell sensitizing drugs are presently undergoing clinical evaluation with some encouraging preliminary results. We review the fundamental concepts underlying these clinical trials and analyze the results.

Kinsella, T.J. (National Cancer Inst., Bethesda, MD); Bloomer, W.D.

1981-04-24

75

A new approach to intraoperative radiation therapy.  

PubMed

Intraoperative radiation therapy (IORT) is an adjuvant treatment in which a large single dose of radiation is delivered during a surgical procedure to resected tumor beds or to an unresectable tumor. This article discusses the implementation of an IORT program and highlights the successful collaboration needed between the OR and radiation oncology departments. A better understanding of IORT in the OR setting will contribute to smooth program implementation. PMID:11665383

Beddar, A S; Kubu, M L; Domanovic, M A; Ellis, R J; Kinsella, T J; Sibata, C H

2001-10-01

76

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

PubMed Central

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

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

2014-01-01

77

Ocular neuromyotonia after radiation therapy  

SciTech Connect

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.

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

1986-12-15

78

Runaway atrioventricular sequential pacemaker after radiation therapy.  

PubMed

Pacemaker malfunction manifested as a runaway circuitry occurred in two patients after they received radiation therapy for treatment of carcinoma. Both pacemakers were programmable atrioventricular sequential units (DVI) with complementary metal oxide semiconductor circuitry. One pacemaker was directly in the radiation field, whereas the other was not directly within the radiation port. Thus, direct irradiation of an implanted pacemaker should be avoided. It is advisable that a pacemaker be shielded even when the pacemaker is not in the direct field of radiation. PMID:3776991

Lee, R W; Huang, S K; Mechling, E; Bazgan, I

1986-11-01

79

Sphenoid Wing en plaque meningiomas: Surgical results and recurrence rates  

PubMed Central

Background: Sphenoid wing en plaque meningiomas are a subgroup of meningiomas defined by its particular sheet-like dural involvement and its disproportionately large bone hyperostosis. En plaque meningiomas represent 2-9% of all meningiomas and they are mainly located in the sphenoid wing. Total surgical resection is difficult and therefore these tumors have high recurrence rates. Methods: Eighteen patients with sphenoid wing en plaque meningiomas surgically treated between January 1998 and December 2008 were included. Clinical, surgical, and follow-up data were retrospectively analyzed. Results: Mean age was 52.2 years and 83% were female. Five patients presented extension of dural component into the orbit and six patients presented cavernous sinus infiltration. Adjuvant radiation therapy was performed in three patients. After a mean follow-up of 4.6 years, five patients developed tumor recurrence - two patients were submitted to surgical treatment and the other three were submitted to radiation therapy. No patient presented recurrence after radiation therapy, whether performed immediately in the postoperative period or performed after recurrence. Patients without tumor extension to cavernous sinus or orbital cavity have the best prognosis treated with surgery alone. When tumor extension involves these locations the recurrence rate is high, especially in cases not submitted to adjuvant radiation therapy. Conclusion: Cavernous sinus and superior orbital fissure involvement are frequent and should be considered surgical limits. Postoperative radiation therapy is indicated in cases with residual tumor in these locations. PMID:23956929

Simas, Nuno M.; Farias, Joao Paulo

2013-01-01

80

Anesthesia for intraoperative radiation therapy in children  

SciTech Connect

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.

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

1987-06-01

81

Radiation Therapy for Pilocytic Astrocytomas of Childhood  

SciTech Connect

Purpose: Though radiation therapy is generally considered the most effective treatment for unresectable pilocytic astrocytomas in children, there are few data to support this claim. To examine the efficacy of radiation therapy for pediatric pilocytic astrocytomas, we retrospectively reviewed the experience at our institution. Methods and Materials: Thirty-five patients 18 years old or younger with unresectable tumors and without evidence of neurofibromatosis have been treated since 1982. Patients were treated with local radiation fields to a median dose of 54 Gy. Six patients were treated with radiosurgery to a median dose of 15.5 Gy. Five patients were treated with initial chemotherapy and irradiated after progression. Results: All patients were alive after a median follow-up of 5.0 years. However, progression-free survival was 68.7%. None of 11 infratentorial tumors progressed compared with 6 of 20 supratentorial tumors. A trend toward improved progression-free survival was seen with radiosurgery (80%) compared with external beam alone (66%), but this difference did not reach statistical significance. Eight of the 9 patients progressing after therapy did so within the irradiated volume. Conclusions: Although the survival of these children is excellent, almost one third of patients have progressive disease after definitive radiotherapy. Improvements in tumor control are needed in this patient population, and the optimal therapy has not been fully defined. Prospective trials comparing initial chemotherapy to radiation therapy are warranted.

Mansur, David B., E-mail: mansur@radonc.wustl.ed [Department of Radiation Oncology, Washington University School of Medicine and Saint Louis Children's Hospital, Saint Louis, MO (United States); Rubin, Joshua B. [Division of Pediatric Hematology and Oncology, Washington University School of Medicine and Saint Louis Children's Hospital, Saint Louis, MO (United States); Kidd, Elizabeth A. [Department of Radiation Oncology, Washington University School of Medicine and Saint Louis Children's Hospital, Saint Louis, MO (United States); King, Allison A. [Division of Pediatric Hematology and Oncology, Washington University School of Medicine and Saint Louis Children's Hospital, Saint Louis, MO (United States); Hollander, Abby S. [Endocrinology, Washington University School of Medicine and Saint Louis Children's Hospital, Saint Louis, MO (United States); Smyth, Matthew D.; Limbrick, David D.; Park, T.S.; Leonard, Jeffrey R. [Department of Neurological Surgery, Washington University School of Medicine and Saint Louis Children's Hospital, Saint Louis, MO (United States)

2011-03-01

82

Early cardiac changes related to radiation therapy  

SciTech Connect

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.

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

1985-12-01

83

Manifestation of palmoplantar pustulosis during or after infliximab therapy for plaque-type psoriasis: report on five cases  

Microsoft Academic Search

Infliximab is a monoclonal antibody directed against TNF-?. It has been approved for use in rheumatoid arthritis, ankylosing\\u000a spondylitis, inflammatory bowel disease, psoriatic arthritis and plaque-type psoriasis. In case reports, positive effects\\u000a on pustular variants of psoriasis have also been reported. However, paradoxically, manifestation of pustular psoriasis and\\u000a plaque-type psoriasis has been reported in patients treated with TNF antagonists including

Rotraut Mössner; Diamant Thaci; Johannes Mohr; Sylvie Pätzold; Hans Peter Bertsch; Ullrich Krüger; Kristian Reich

2008-01-01

84

Manifestation of palmoplantar pustulosis during or after inXiximab therapy for plaque-type psoriasis: report on Wve cases  

Microsoft Academic Search

InXiximab is a monoclonal antibody directed against TNF-. It has been approved for use in rheumatoid arthritis, ankylosing spondylitis, inXammatory bowel dis- ease, psoriatic arthritis and plaque-type psoriasis. In case reports, positive eVects on pustular variants of psoriasis have also been reported. However, paradoxically, manifes- tation of pustular psoriasis and plaque-type psoriasis has been reported in patients treated with TNF

Rotraut Mössner; Diamant Thaci; Johannes Mohr; Sylvie Pätzold; Hans Peter Bertsch; Ullrich Krüger; Kristian Reich

85

Response of feline eosinophilic plaques and lip ulcers to amoxicillin trihydrate-clavulanate potassium therapy: a randomized, double-blind placebo-controlled prospective study.  

PubMed

In this study, we evaluated the treatment of feline eosinophilic plaques and lip ulcers with amoxicillin trihydrate-potassium clavulanate (Clavamox(®); Pfizer Animal Health). Nineteen cats with clinical and cytological findings consistent with eosinophilic plaques and/or lip ulcers were enrolled. Lesions were photographed and their areas measured in square centimetres before and after 21 days of therapy with either flavoured amoxicillin-clavulanate suspension or flavoured placebo suspension. Sixteen cats completed the study, with nine plaque lesions (four treatment and five placebo) and eight lip ulcer lesions (four treatment and four placebo) included in the analysis. All lesions were shown to have infection, with bacterial phagocytosis present on cytological examination. Coagulase-positive staphylococci were the most commonly isolated bacteria. The amoxicillin-clavulanate-treated eosinophilic plaque group had a statistically significant 96.2% reduction in mean lesion size (-7.60 cm(2), P = 0.0078) and an 80% reduction in mean percentage of microscopic fields demonstrating evidence of bacterial infection (P < 0.0001), whereas the placebo group did not. The amoxicillin-clavulanate-treated lip ulcer group had a 42.6% decrease in mean lesion size (-0.25 cm(2), P = 0.4125) and the placebo group a 36.6% increase (+0.49 cm(2), P = 0.1575), although neither change was statistically significant. The amoxicillin-clavulanate-treated lip ulcer group had a statistically significant 65.0% reduction in mean percentage of microscopic fields demonstrating evidence of bacterial infection (P < 0.0001), while no significant reduction was observed in the placebo group. A suspension of amoxicillin trihydrate-potassium clavulanate is an effective monotherapy for the treatment of feline eosinophilic plaques. PMID:22132827

Wildermuth, Brett E; Griffin, Craig E; Rosenkrantz, Wayne S

2012-04-01

86

Process of Coping with Radiation Therapy.  

ERIC Educational Resources Information Center

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…

Johnson, Jean E.; And Others

1989-01-01

87

Precise positioning of patients for radiation therapy  

Microsoft Academic Search

A number of immobilization schemes which permit precise daily positioning of patients for radiation therapy are discussed. Pretreatment and post-treatment radiographs have been taken with the patient in the treatment position and analyzed to determine the amount of intratreatment movement. Studies of patients in the supine, seated and decubitus positions indicate mean movements of less than 1 mm with a

Lynn J. Verhey; Michael Goitein; Patricia McNulty; John E. Munzenrider; Herman D. Suit

1982-01-01

88

Comparing Radiation Therapies for Prostate Cancer  

Cancer.gov

In this trial, men with favorable-risk, localized prostate cancer will be randomly assigned to receive conventionally fractionated radiation therapy over the course of about eight weeks (41 daily treatments) or hypofractionated radiotherapy over a five-and-a-half week period (28 daily treatments).

89

DISCIPLINE OF RADIATION THERAPY SAFETY DOCUMENT  

E-print Network

of Staff 10 6.6 Students 10 6.7 Fire Wardens 10 7. Electrical safety 11 8. Security in College 12 8DISCIPLINE OF RADIATION THERAPY SAFETY DOCUMENT Contents Page 1. Health & Safety arrangements 1.1 Information, Instruction, Training & Supervision 1.2 Accident / Incident Reporting & Investigation 1.3 Safety

O'Mahony, Donal E.

90

Glossodynia after radiation therapy and chemotherapy  

SciTech Connect

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.

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

1989-10-01

91

Low-Dose Pretreatment for Radiation Therapy  

PubMed Central

In radiotherapy, a large radiation dose must be applied to both cancer and neighboring healthy cells. Recent experiments have shown that a low dose of ionizing radiation turns on certain protective mechanisms that allow a cell to better survive a subsequent high dose of radiation. This adaptive response can have important and positive consequences for radiotherapy. This paper describes a simple change in treatment procedures to make use of these beneficial effects. A low dose applied only to the healthy cells will probably produce some damage. However, it will also start the adaptive response which will yield increased protection when the large therapeutic dose is applied. The resultant immediate damage will be thereby reduced as well as the probability that the high dose therapy itself will induce a subsequent secondary cancer. After a brief historical review, the effects of a low radiation dose on a canine cancer cell line will be discussed as well as trials of the suggested pre-dose therapy on canine cancer patients undergoing standard radiation therapy. PMID:21191490

Blankenbecler, Richard

2010-01-01

92

Stereotactic body radiation therapy for liver tumors.  

PubMed

Recent improvements in radiation therapy delivery techniques provide new tools to treat patients with liver-confined disease, either with hepatocellular carcinoma or liver metastases. An appropriate selection of the patients made during a multidisciplinary specialized tumour board is mandatory. It should be based on the disease extension, an accurate evaluation of the comorbidities and the liver functions. The added value of this approach has to be evaluated in well-designed trials, alone or in combination with other treatments such as surgery, local treatments, chemoembolization and/or chemotherapy with or without targeted agents. Stereotactic body radiation therapy should be applied under strict conditions of expertise of the radiation oncology departments, including equipment and educational training programmes. However under these conditions, preliminary results seems highly encouraging in terms of local control and tolerance but should be confirmed in large controlled prospective trials. PMID:24958684

Maingon, P; Nouhaud, É; Mornex, F; Créhange, G

2014-01-01

93

[Radiation therapy in France in 2010].  

PubMed

Radiation therapy contributes, with others therapeutic means, to cure many cancers without mutilation and sparing conservative functions. In France, in 2010, about 180,000 patients underwent external radiation therapy in 177 centers assumed by 660 radiation oncologists. Many progress and changes have been made during the past years with the implementation of new techniques as conformal and intensity modulated techniques. Renewal of innovative treatment machines is rapidly ongoing. Since 2007, after medical accidents, quality and security policies have been improved and coordinated to a national level with the active cooperation of the main institutional and professional partners. The new national "Plan Cancer 2009-2013" leads to improvement for patients to access to innovative and safe treatments and to clinical research. PMID:21452548

Kantor, Guy; Chauvet, Bruno; Lartigau, Eric

2011-01-01

94

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 ...

95

automated improvement of radiation therapy treatment plans by ...  

E-print Network

Automated improvement of radiation therapy treatment plans. Consequently ...... The research was supported by the Swedish Research Council. (VR). ... [13] J. Löf. Development of a general framework for optimization of radiation therapy.

2012-11-06

96

Comparison of particle-radiation-therapy modalities  

SciTech Connect

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.

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

1981-01-01

97

Radiation therapy for orbital lymphoma  

SciTech Connect

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.

Zhou Ping [Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA (United States)]. E-mail: pzhou@partners.org; Ng, Andrea K. [Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA (United States); Silver, Barbara [Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA (United States); Li Sigui [Department of Biostatistical Sciences, Dana-Farber Cancer Institute, Boston, MA (United States); Hua Ling [Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA (United States); Mauch, Peter M. [Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA (United States)

2005-11-01

98

Gastrointestinal toxicity associated to radiation therapy.  

PubMed

Radiation therapy in combination with other treatments, such as surgery and chemotherapy, increases locoregional control and survival in patients with thoracic, abdominal and pelvic malignancies. Nevertheless, significant clinical toxicity with combined treatments may be seen in these patients. With the advent of tridimensional conformal radiotherapy (3D-CRT), dose-volume histograms (DVH) can be generated to assess the dose received by the organs at risk. The possible relationship between these parameters and clinical, anatomical and, more recently, genetic factors has to be considered. Treatment options include initial conservative medical therapies, endoscopic procedures, hyperbaric oxygen and surgery. Some pharmacological agents to prevent gastrointestinal toxicity are under investigation. PMID:20709653

Rodríguez, Mario López; Martín, Margarita Martín; Padellano, Laura Cerezo; Palomo, Alicia Marín; Puebla, Yamile Ibáñez

2010-08-01

99

Exclusive plaque psoriasis of the lips: efficacy of combination therapy of topical tacrolimus, calcipotriol, and betamethasone dipropionate.  

PubMed

A 16-year-old unmarried woman presented with recurrent cracking of the lips indicated by the appearance of grayish white flakes since October 2004, which, in due course, shed off leaving behind an apparently normal mucous membrane. Chewing roasted corn treated with salt and lemon (bhutta) initially caused the lesions. Ever since, it has been a cause of its exacerbation. She never had any relief with either systemic or topical treatment. In fact, an obsession had overtaken her, resulting in a psychological setback. She denied regular drug use for any other ailment. Her menstrual cycle was normal. There was a positive history of psoriasis in her mother. Examination of the lips was conspicuous. It was marked by the presence of a well-circumscribed, moist, raised plaque (Figure 1). Its surface was irregular, with elevation and depression. It was made up of thick, grayish white scales, which were arranged in layers; however, Grattage/Auspitz sign could not be elicited. Fissuring was prominent but the buccal mucosa, surface of the tongue, gingiva, and palate were normal. The clinical examination did not reveal any evidence of skin and/or nail psoriasis/psoriatic arthropathy or any other systemic abnormality. Blood examination including total and differential leukocyte count, complete hemogram, and liver and renal function tests were normal. Biopsy of the representative lesion was subjected to serial sections. They were stained with hematoxylin-eosin to work up microscopic pathology. It revealed the presence of mounds of parakeratosis with numerous neutrophilic Munro microabscesses (Figure 2). Submucosal vessels were dilated and congested. Periodic-acid-Schiff (PAS) stain revealed fungal hyphae and spores within the parakeratotic layer. Colonies of Gram-positive cocci were also demonstrated on the surface of the mucosa. She was administered combination therapy, comprising topical tacrolimus (0.1%) ointment and calcipotirol hydrate (50 microg/g) plus betmethasone dipropionate (0.5 mg/g) twice a day for 7 days. A single bolus dose of fluconazole 450 mg orally was also administered. The response to treatment was favorable and the lesions showed regression (Figure 3). PMID:22779103

Sehgal, Virendra N; Sehgal, Shruti; Verma, Prashant; Singh, Navjeevan; Rasool, Farhan

2012-01-01

100

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

SciTech Connect

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.

Khan, Niloufer [Case Western Reserve University School of Medicine, Cleveland, OH (United States); Khan, Mohammad K., E-mail: drkhurram2000@gmail.com [Taussig Cancer Institute, Lerner College of Medicine and Cole Eye Institute, Cleveland Clinic, Cleveland, OH (United States); Almasan, Alex; Singh, Arun D.; Macklis, Roger [Taussig Cancer Institute, Lerner College of Medicine and Cole Eye Institute, Cleveland Clinic, Cleveland, OH (United States)

2011-07-01

101

Mobile linear accelerators for intraoperative radiation therapy.  

PubMed

Intraoperative radiation therapy (IORT) is becoming an increasingly common procedure for treating gross tumors or tumor beds after resection. Traditionally, IORT delivery required either heavily shielded ORs or transporting anesthetized patients to the department of radiation oncology. The availability of a self-shielded mobile electron linear accelerator has made this treatment modality accessible to institutions that otherwise would not consider performing IORT. This article describes IORT equipment and supplies and addresses perioperative nursing issues, as well as the roles of other team members involved in the delivery of IORT. PMID:11725448

Beddar, A S; Domanovic, M A; Kubu, M L; Ellis, R J; Sibata, C H; Kinsella, T J

2001-11-01

102

Curative radiation therapy in prostate cancer.  

PubMed

Radiotherapy has experienced an extremely rapid development in recent years. Important improvements such as the introduction of multileaf collimators and computed tomography (CT)-based treatment planning software have enabled three dimensional conformal external beam radiation therapy (3DCRT). The development of treatment planning systems and technology for brachytherapy has been very rapid as well. Development of accelerators with integrated on-board imaging equipment and technology, for example image-guided radiation therapy (IGRT) has further improved the precision with reduced margins to adjacent normal tissues. This has, in turn, led to the possibility to administer even higher doses to the prostate than previously. Although radiotherapy and radical prostatectomy have been used for the last decades as curative treatment modalities, still there are no randomized trials published comparing these two options. Outcome data show that the two treatment modalities are highly comparable when used for low- and intermediate-risk prostate cancer. PMID:21604948

Harmenberg, Ulrika; Hamdy, Freddie C; Widmark, Anders; Lennernäs, Bo; Nilsson, Sten

2011-06-01

103

Vulnerable Plaque  

MedlinePLUS

... within an artery leading to the heart or brain. With time, the plaque buildup would narrow the artery so much that the artery would either close off or become clogged by a blood clot (much like a clogged drain). The lack of oxygen-rich blood to the ...

104

Fishbowl Plaques.  

ERIC Educational Resources Information Center

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)

Lambert, Phyllis Gilchrist

1998-01-01

105

Magnetic tracking system for radiation therapy.  

PubMed

Intensity-modulated radiation therapy (IMRT) requires precise delivery of the prescribed dose of radiation to the target and surrounding tissue. Irradiation of moving body anatomy is possible only if stable, accurate, and reliable information about the moving body structures are provided in real time. This paper presents a magnetic position tracking system for radiation therapy. The proposed system uses only four transmitting coils and an implantable transponder. The four transmitting coils generate a magnetic field which is sensed and measured by a biaxial magnetoresistive sensor in the transponder in the tumor. The transponder transmits the information back to a computer to determine the position of the transponder allowing it to track the tumor in real time. The transmission of the information from the transponder to the computer can be wired or wireless. Measurements using a biaxial sensor agree well with the field strength calculated from the ideal equations. The translation from the measurement data to the 3-D location and orientation requires a numerical technique because the equations are in nonclosed forms. The algorithm of tracking is implemented using MATLAB. Each calculation of the position along the target trajectory takes 30 ms, which makes the proposed system suitable for real-time tracking of the transponder for radiation assessment and delivery. An error of less than 2 mm is achieved in the demonstration. PMID:23853368

Wing-Fai Loke; Tae-Young Choi; Maleki, Teimour; Papiez, Lech; Ziaie, Babak; Byunghoo Jung

2010-08-01

106

Automatic field shaping for conformal radiation therapy.  

PubMed

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

Ayyangar, K

1994-04-01

107

Generalized Morphea after Breast Cancer Radiation Therapy  

PubMed Central

We present a case of a 69-year-old woman who received external beam radiation for the treatment of breast cancer. Seven months later, she developed generalized morphea involving the area of irradiated skin of the breast as well as distant sites of the groin and distal lower extremity. Postirradiation morphea is an uncommon yet well-documented phenomenon, usually confined to the radiated site and the immediate surrounding tissue. To our knowledge, this is only the fourth reported case of morphea occurring distant from the radiation field. While most cases of postirradiation morphea have been shown to either resolve spontaneously or respond to topical corticosteroids, our patient required systemic therapy with methotrexate, which resulted in clinical improvement. With this paper, we hope to bring further awareness to this phenomenon and demonstrate a successful treatment response with the use of methotrexate in postirradiation generalized morphea. PMID:22937449

Kushi, Jonathan; Csuka, M. E.

2011-01-01

108

Image-guided radiation therapy: Physician's perspectives  

PubMed Central

The evolution of radiotherapy has been ontogenetically linked to medical imaging. Over the years, major technological innovations have resulted in substantial improvements in radiotherapy planning, delivery, and verification. The increasing use of computed tomography imaging for target volume delineation coupled with availability of computer-controlled treatment planning and delivery systems have progressively led to conformation of radiation dose to the target tissues while sparing surrounding normal tissues. Recent advances in imaging technology coupled with improved treatment delivery allow near-simultaneous soft-tissue localization of tumor and repositioning of patient. The integration of various imaging modalities within the treatment room for guiding radiation delivery has vastly improved the management of geometric uncertainties in contemporary radiotherapy practice ushering in the paradigm of image-guided radiation therapy (IGRT). Image-guidance should be considered a necessary and natural corollary to high-precision radiotherapy that was long overdue. Image-guided radiation therapy not only provides accurate information on patient and tumor position on a quantitative scale, it also gives an opportunity to verify consistency of planned and actual treatment geometry including adaptation to daily variations resulting in improved dose delivery. The two main concerns with IGRT are resource-intensive nature of delivery and increasing dose from additional imaging. However, increasing the precision and accuracy of radiation delivery through IGRT is likely to reduce toxicity with potential for dose escalation and improved tumor control resulting in favourable therapeutic index. The radiation oncology community needs to leverage this technology to generate high-quality evidence to support widespread adoption of IGRT in contemporary radiotherapy practice. PMID:23293448

Gupta, T.; Narayan, C. Anand

2012-01-01

109

[Therapy options in relapsing prostate cancer after external radiation therapy].  

PubMed

In the near future, the number of young patients suffering from locoregional recurrence of their prostate cancer after external beam radiation will increase. For these patients, androgen deprivation is the most widely used therapy, but it is only palliative. Salvage radical prostatectomy, cryoablation, interstitial brachytherapy, and high-intensity focused ultrasound (HIFU) are treatment options with the potential of curing the patient. Currently, salvage radical prostatectomy offers the best chance for cure. Although a significant reduction in peri- and postoperative complication rates has been reported, surgery remains technically challenging, with a high rate of urinary incontinence. We believe that salvage prostatectomy should be considered only for patients in good general health whose life expectancy is more than 10 years and whose cancer was initially organ-confined before radiation therapy. Salvage cryotherapy might be an alternative to surgery. Complication rates have decreased as technical application has improved considerably within the last years. A major drawback of cryoablation is its lack of reliable and complete ablation of all prostate cells. HIFU and interstitial brachytherapy are minimally invasive salvage options that have been investigated in small clinical studies. PMID:17356831

Häcker, A; Alken, P

2007-04-01

110

Recall radiation dermatitis by sorafenib following stereotactic body radiation therapy  

PubMed Central

We report on a 63-year-old man with a history of hepatitis B virus–related hepatocellular carcinoma with a thrombus extending into the inferior vena cava, who received image-guided stereotactic body radiation therapy (SBRT) with helical tomotherapy, followed by sorafenib. A total tumor dose of 48 Gy was delivered by 6 fractions within 2 weeks. The tumor responded dramatically, and the patient tolerated the courses well. Ten days after SBRT, sorafenib (200 mg), at 1.5 tablets twice a day, was prescribed. One week later, grade 2 recall radiation dermatitis subsequently developed in the previous SBRT off-target area. SBRT followed by sorafenib for the treatment of a portal vein thrombosis provided effective results, but the potential risk of enhanced adverse effects between radiation and sorafenib should be considered with caution, especially under a SBRT scheme. PMID:24971021

Hsieh, Chen-Hsi; Lin, Shih-Chiang; Shueng, Pei-Wei; Kuo, Deng-Yu

2014-01-01

111

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

PubMed

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

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

2013-09-01

112

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

PubMed Central

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

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

2014-01-01

113

Radiation and chemoradiation therapy for esophageal adenocarcinoma.  

PubMed

The aims of preoperative chemoradiation therapy (preop-CRT) for esophageal adenocarcinoma are to reduce incomplete local resection (R1,R2), local and systemic recurrences that are reported in up to 30% of patients who undergo surgery alone. Phase II studies of preop-CRT, with radiation doses in the 40-50 Gy range, and concurrent chemotherapy with 5-fluorouracil (5-FU)-cisplatin +/- paclitaxel, or cisplatin-paclitaxel, have reported subsequent RO resection rates of 80%-100%, with tumor sterilization achieved in 8%-49% of cases, and consequently improved local control. New chemotherapy regimens omitting 5-FU have reduced the incidence of severe esophagitis, unplanned hospitalization, with comparable efficacy. Among three randomised trials that compared preop-CRT to surgery alone, one shown a debatable survival advantage. Reducing local recurrence rates lead to a switch to more distant failures, and increasing the radiation dose beyond 45 Gy appears to be of little value. However, it should be remembered that preop-CRT has associated toxicity, and may increase postoperative mortality. Novel strategies, which include induction with chemotherapy followed by preop-CRT, and for radiation therapy, three dimensional conformation techniques, image fusioning, and improved definition of treatment volumes, are still considered experimental and should be tested in specialized centers. PMID:16299784

Bosset, Jean-François; Lorchel, F; Mantion, G; Buffet, J; Créhange, G; Bosset, M; Chaigneau, L; Servagi, S

2005-12-01

114

Molecular Pathways: Targeted ?-Particle Radiation Therapy  

PubMed Central

An ?-particle, a 4He nucleus, is exquisitely cytotoxic, and indifferent to many limitations associated with conventional chemo- and radiotherapy. The exquisite cytotoxicity of ? 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 ?-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 ?-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 ?-emitters such as 225Ac, 211At, 213Bi, 212Pb and 223Ra. PMID:23230321

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

2012-01-01

115

Ionizing radiation: a genetic switch for cancer therapy  

Microsoft Academic Search

Gene therapy of cancer represents a promising but challenging area of therapeutic research. The discovery of radiation-inducible genes led to the concept and development of radiation-targeted gene therapy. In this approach, promoters of radiation-inducible genes are used to drive transcription of transgenes in the response to radiation. Constructs in which the radiation-inducible promoter elements activate a transgene encoding a cytotoxic

J J Mezhir; K D Smith; M C Posner; N Senzer; B Yamini; D W Kufe; R R Weichselbaum

2006-01-01

116

HYPERBARIC OXYGEN THERAPY FOR RADIATION INDUCED HEMORRHAGIC CYSTITIS  

Microsoft Academic Search

PurposeRadiation therapy has been used successfully to treat pelvic malignancy but morbidity from hemorrhagic cystitis remains a major long-term sequela in 1 to 2% of patients. Obliterative endarteritis secondary to ionizing radiation leads to tissue hypoxia and poor healing. Hyperbaric oxygen therapy has been demonstrated to improve angiogenesis and promote healing in radiation injured tissue, including the bladder. We describe

RANJIV MATHEWS; NATARAJAN RAJAN; LAURA JOSEFSON; ENRICO CAMPORESI; ZAHI MAKHULI

1999-01-01

117

Intraoperative Radiation Therapy in Gastric Cancer  

PubMed Central

Abstract Gastric cancer is one of the most common malignancies worldwide. Although surgery is the only potential curative treatment, the overall survival results remain poor due to the high risks of recurrence, so scientists developed new aggressive adjuvant therapies. That is how the IORT appeared. IORT is a technique designed to provide a large radiation dose to a target tissue considered of being "at risk" to develop recurrence. In this review we resume recent publications which debate the use, efficacy and the overall survival after IORT.

Bacalba?a, N; B?lescu, I; Calin, M; Balalau, C

2014-01-01

118

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

Microsoft Academic Search

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

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

2010-01-01

119

Mapping the literature of radiation therapy  

PubMed Central

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

Delwiche, Frances A.

2013-01-01

120

How Should I Care for Myself During Radiation Therapy?  

MedlinePLUS

... Prostate Skin Upper GI Latest Research 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 ...

121

Film Dosimetry for Intensity Modulated Radiation Therapy  

NASA Astrophysics Data System (ADS)

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.

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

2004-09-01

122

[Stereotactic body radiation therapy: uncertainties and margins].  

PubMed

The principles governing stereotactic body radiation therapy are tight margins and large dose gradients around targets. Every step of treatment preparation and delivery must be evaluated before applying this technique in the clinic. Uncertainties remain in each of these steps: delineation, prescription with the biological equivalent dose, treatment planning, patient set-up taking into account movements, the machine accuracy. The calculation of margins to take into account uncertainties differs from conventional radiotherapy because of the delivery of few fractions and large dose gradients around the target. The quest of high accuracy is complicated by the difficulty to reach it and the lack of consensus regarding the prescription. Many schemes dose/number of fractions are described in clinical studies and there are differences in the way describing the delivered doses. While waiting for the ICRU report dedicated to this technique, it seems desirable to use the quantities proposed in ICRU Report 83 (IMRT) to report the dose distribution. PMID:25023588

Lacornerie, T; Marchesi, V; Reynaert, N

2014-01-01

123

Radiation therapy for primary vaginal carcinoma.  

PubMed

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

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

2013-09-01

124

Conformal Proton Radiation Therapy for Pediatric Low-Grade Astrocytomas  

Microsoft Academic Search

Background: To evaluate the safety and efficacy of proton radiation therapy (PRT) for intracranial low-grade astrocytomas, the authors analyzed the first 27 pediatric patients treated at Loma Linda University Medical Center (LLUMC). Patients and Method: Between September 1991 and August 1997, 27 patients (13 female, 14 male) underwent fractionated proton radiation therapy for progressive or recurrent low-grade astrocytoma. Age at

Eugen B. Hug; Marc W. Muenter; John O. Archambeau; Alexander DeVries; Boleslaw Liwnicz; Lilia N. Loredo; Roger I. Grove; Jerry D. Slater

2002-01-01

125

Radiation Therapy and the Management of Intramedullary Spinal Cord Tumors  

Microsoft Academic Search

The use of radiation therapy in the management of intramedullary spinal cord tumors remains controversial. Several studies indicate that the use of postoperative radiation therapy modestly improves both local control and survival in spinal cord ependymomas and astrocytomas. Modern treatment planning and imaging allow more accurate target definition and respect for related normal tissue tolerances.

Steven R. Isaacson

2000-01-01

126

Hyperbaric Oxygen Therapy for Radiation-induced Optic Neuropathy  

Microsoft Academic Search

Introduction: Radiation-induced optic neuropathy (RON) is an infrequent but devastating consequence of radiation exposure to the visual pathways, usually following months to years after the treatment of paranasal or intracranial tumours. Hyperbaric oxygen (HBO) therapy is one of several therapies that have been tried for this condition. The purpose of this review is to describe the clinical characteristics of RON,

Richard L Levy; Neil R Miller

127

Precise positioning of patients for radiation therapy  

SciTech Connect

A number of immobilization schemes which permit precise daily positioning of patients for radiation therapy are discussed. Pretreatment and post-treatment radiographs have been taken with the patient in the treatment position and analyzed to determine the amount of intratreatment movement. Studies of patients in the supine, seated and decubitus positions indicate mean movements of less than 1 mm with a standard deviation of less than 1 mm. Patients immobilized in the seated position with a bite block and a mask have a mean movement of about 0.5 mm +/- 0.3 mm (s.d.), and patients immobilized in the supine position with their necks hyperextended for submental therapy evidence a mean movement of about 1.4 mm +/- 0.9 mm (s.d.). With the exception of those used for the decubitus position, the immobilization devices are simply fabricated out of thermoplastic casting materials readily available from orthopedic supply houses. A study of day-to-day reproducibility of patient position using laser alignment and pretreatment radiographs for final verification of position indicates that the initial laser alignment can be used to position a patient within 2.2 mm +/- 1.4 mm (s.d.) of the intended position. These results indicate that rigid immobilization devices can improve the precision of radiotherapy, which would be advantageous with respect to both tumor and normal tissue coverage in certain situations.

Verhey, L.J.; Goitein, M.; McNulty, P.; Munzenrider, J.E.; Suit, H.D.

1982-02-01

128

Advances in Radiation Therapy for Cancer: NCI Science Writers Seminar  

Cancer.gov

A science writers' seminar to discuss new treatments, technologies and research advances in radiation therapy for cancer. The opening of the new Roberts Proton Therapy Center at Penn Medicine, the world's largest proton therapy facility, highlights these growing trends in cancer care.

129

Stereotactic body radiation therapy for liver metastases  

PubMed Central

Over the years, early diagnosis of metastatic disease has improved and the prevalence of oligometastatic patients is increasing. Liver is a most common site of progression from gastrointestinal, lung and breast cancer and in the setting of oligometastatic patients, surgical resection is associated with increased survival. Approximately 70-90% of liver metastases, however, are unresectable and an effective and safe alternative therapeutic option is necessary for these patients. The role of stereotactic body radiation therapy (SBRT) was investigated in the treatment of oligometastatic patients with promising results, thanks to the ability of this procedure to deliver a conformal high dose of radiation to the target lesion and a minimal dose to surrounding critical tissues. This paper was performed to review the current literature and to provide the practice guidelines on the use of stereotactic body radiotherapy in the treatment of liver metastases. We performed a literature search using Medical Subject Heading terms “SBRT” and “liver metastases”, considering a period of ten years. PMID:24982767

Clerici, Elena; Comito, Tiziana

2014-01-01

130

Stereotactic body radiation therapy for liver metastases.  

PubMed

Over the years, early diagnosis of metastatic disease has improved and the prevalence of oligometastatic patients is increasing. Liver is a most common site of progression from gastrointestinal, lung and breast cancer and in the setting of oligometastatic patients, surgical resection is associated with increased survival. Approximately 70-90% of liver metastases, however, are unresectable and an effective and safe alternative therapeutic option is necessary for these patients. The role of stereotactic body radiation therapy (SBRT) was investigated in the treatment of oligometastatic patients with promising results, thanks to the ability of this procedure to deliver a conformal high dose of radiation to the target lesion and a minimal dose to surrounding critical tissues. This paper was performed to review the current literature and to provide the practice guidelines on the use of stereotactic body radiotherapy in the treatment of liver metastases. We performed a literature search using Medical Subject Heading terms "SBRT" and "liver metastases", considering a period of ten years. PMID:24982767

Scorsetti, Marta; Clerici, Elena; Comito, Tiziana

2014-06-01

131

Laboratory Investigation Synergy of gene-mediated immunoprophylaxis and microbeam radiation therapy  

E-print Network

Laboratory Investigation Synergy of gene-mediated immunoprophylaxis and microbeam radiation therapy radiation therapy, rats Summary Purpose: Microbeam radiation therapy (MRT), a novel experimental animals and palliates advanced 9LGS tumors. This report, to our knowledge, is the first demonstration

Terasaki, Mark

132

Cancer and Radiation Therapy: Current Advances and Future Directions  

PubMed Central

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

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

2012-01-01

133

The Ethics of Disclosure - Perspectives of Radiation Therapists and Patients Regarding Disclosure of Radiation Therapy Errors  

Microsoft Academic Search

The ethical principles of veracity and patient autonomy suggestthat patients should be informed of any errors that occur during their care. A survey of Radiation Therapists (RT's) and patients undergoing radiation therapy was used to obtain data regarding attitudes toward disclosure of errors that may occur during a course of radiation therapy treatment. Both RT's and patients agreed that potentially

John French

2004-01-01

134

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

PubMed

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

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

2007-11-01

135

Intensity-modulated radiation therapy: emerging cancer treatment technology  

Microsoft Academic Search

The use of intensity-modulated radiation therapy (IMRT) is rapidly advancing in the field of radiation oncology. Intensity-modulated radiation therapy allows for improved dose conformality, thereby affording the potential to decrease the spectrum of normal tissue toxicities associated with IMRT. Preliminary results with IMRT are quite promising; however, the clinical data is relatively immature and overall patient numbers remain small. High-quality

T S Hong; M A Ritter; W A Tomé; P M Harari

2005-01-01

136

Radiation pneumonitis after stereotactic radiation therapy for lung cancer.  

PubMed

Stereotactic body radiation therapy (SBRT) has a local control rate of 95% at 2 years for non-small cell lung cancer (NSCLC) and should improve the prognosis of inoperable patients, elderly patients, and patients with significant comorbidities who have early-stage NSCLC. The safety of SBRT is being confirmed in international, multi-institutional Phase II trials for peripheral lung cancer in both inoperable and operable patients, but reports so far have found that SBRT is a safe and effective treatment for early-stage NSCLC and early metastatic lung cancer. Radiation pneumonitis (RP) is one of the most common toxicities of SBRT. Although most post-treatment RP is Grade 1 or 2 and either asymptomatic or manageable, a few cases are severe, symptomatic, and there is a risk for mortality. The reported rates of symptomatic RP after SBRT range from 9% to 28%. Being able to predict the risk of RP after SBRT is extremely useful in treatment planning. A dose-effect relationship has been demonstrated, but suggested dose-volume factors like mean lung dose, lung V20, and/or lung V2.5 differed among the reports. We found that patients who present with an interstitial pneumonitis shadow on computed tomography scan and high levels of serum Krebs von den Lungen-6 and surfactant protein D have a high rate of severe radiation pneumonitis after SBRT. At our institution, lung cancer patients with these risk factors have not received SBRT since 2006, and our rate of severe RP after SBRT has decreased significantly since then. PMID:25276313

Yamashita, Hideomi; Takahashi, Wataru; Haga, Akihiro; Nakagawa, Keiichi

2014-09-28

137

Radiation pneumonitis after stereotactic radiation therapy for lung cancer  

PubMed Central

Stereotactic body radiation therapy (SBRT) has a local control rate of 95% at 2 years for non-small cell lung cancer (NSCLC) and should improve the prognosis of inoperable patients, elderly patients, and patients with significant comorbidities who have early-stage NSCLC. The safety of SBRT is being confirmed in international, multi-institutional Phase II trials for peripheral lung cancer in both inoperable and operable patients, but reports so far have found that SBRT is a safe and effective treatment for early-stage NSCLC and early metastatic lung cancer. Radiation pneumonitis (RP) is one of the most common toxicities of SBRT. Although most post-treatment RP is Grade 1 or 2 and either asymptomatic or manageable, a few cases are severe, symptomatic, and there is a risk for mortality. The reported rates of symptomatic RP after SBRT range from 9% to 28%. Being able to predict the risk of RP after SBRT is extremely useful in treatment planning. A dose-effect relationship has been demonstrated, but suggested dose-volume factors like mean lung dose, lung V20, and/or lung V2.5 differed among the reports. We found that patients who present with an interstitial pneumonitis shadow on computed tomography scan and high levels of serum Krebs von den Lungen-6 and surfactant protein D have a high rate of severe radiation pneumonitis after SBRT. At our institution, lung cancer patients with these risk factors have not received SBRT since 2006, and our rate of severe RP after SBRT has decreased significantly since then.

Yamashita, Hideomi; Takahashi, Wataru; Haga, Akihiro; Nakagawa, Keiichi

2014-01-01

138

Radiation Therapy for Chloroma (Granulocytic Sarcoma)  

SciTech Connect

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.

Bakst, Richard; Wolden, Suzanne [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Yahalom, Joachim, E-mail: yahalomj@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2012-04-01

139

Scatter factors assessment in microbeam radiation therapy  

SciTech Connect

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.

Prezado, Y.; Martinez-Rovira, I.; Sanchez, M. [Laboratoire Imagerie et Modelisation en Neurobiologie et Cancerologie IMNC-UMR 8165, Centre National de la Recherche Scientifique (CNRS), Campus Universitaire, Bat. 440, 15 rue Georges Clemenceau, 91406 Orsay Cedex (France); Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, E-08028 Barcelona (Spain) and ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz, B.P. 220, 38043 Grenoble Cedex (France); Servicio de Radiofisica, Complejo Hospitalario de Santiago de Compostela, Rua Choupana S/N, 15706 Santiago de Compostela (Spain)

2012-03-15

140

On probabilistically defined margins in radiation therapy.  

PubMed

Margins about a target volume subject to external beam radiation therapy are designed to assure that the target volume of tissue to be sterilized by treatment is adequately covered by a lethal dose. Thus, margins are meant to guarantee that all potential variation in tumour position relative to beams allows the tumour to stay within the margin. Variation in tumour position can be broken into two types of dislocations, reducible and irreducible. Reducible variations in tumour position are those that can be accommodated with the use of modern image-guided techniques that derive parameters for compensating motions of patient bodies and/or motions of beams relative to patient bodies. Irreducible variations in tumour position are those random dislocations of a target that are related to errors intrinsic in the design and performance limitations of the software and hardware, as well as limitations of human perception and decision making. Thus, margins in the era of image-guided treatments will need to accommodate only random errors residual in patient setup accuracy (after image-guided setup corrections) and in the accuracy of systems designed to track moving and deforming tissues of the targeted regions of the patient's body. Therefore, construction of these margins will have to be based on purely statistical data. The characteristics of these data have to be determined through the central limit theorem and Gaussian properties of limiting error distributions. In this paper, we show how statistically determined margins are to be designed in the general case of correlated distributions of position errors in three-dimensional space. In particular, we show how the minimal margins for a given level of statistical confidence are found. Then, how they are to be used to determine geometrically minimal PTV that provides coverage of GTV at the assumed level of statistical confidence. Our results generalize earlier recommendations for statistical, central limit theorem-based recommendations for margin construction that were derived for uncorrelated distributions of errors (van Herk, Remeijer, Rasch and Lebesque 2000 Int. J. Radiat. Oncol. Biol. Phys. 47 1121-35; Stroom, De Boer, Huizenga and Visser 1999 Int. J. Radiat. Oncol. Biol. Phys. 43 905-19). PMID:16885615

Papiez, Lech; Langer, Mark

2006-08-21

141

On probabilistically defined margins in radiation therapy  

NASA Astrophysics Data System (ADS)

Margins about a target volume subject to external beam radiation therapy are designed to assure that the target volume of tissue to be sterilized by treatment is adequately covered by a lethal dose. Thus, margins are meant to guarantee that all potential variation in tumour position relative to beams allows the tumour to stay within the margin. Variation in tumour position can be broken into two types of dislocations, reducible and irreducible. Reducible variations in tumour position are those that can be accommodated with the use of modern image-guided techniques that derive parameters for compensating motions of patient bodies and/or motions of beams relative to patient bodies. Irreducible variations in tumour position are those random dislocations of a target that are related to errors intrinsic in the design and performance limitations of the software and hardware, as well as limitations of human perception and decision making. Thus, margins in the era of image-guided treatments will need to accommodate only random errors residual in patient setup accuracy (after image-guided setup corrections) and in the accuracy of systems designed to track moving and deforming tissues of the targeted regions of the patient's body. Therefore, construction of these margins will have to be based on purely statistical data. The characteristics of these data have to be determined through the central limit theorem and Gaussian properties of limiting error distributions. In this paper, we show how statistically determined margins are to be designed in the general case of correlated distributions of position errors in three-dimensional space. In particular, we show how the minimal margins for a given level of statistical confidence are found. Then, how they are to be used to determine geometrically minimal PTV that provides coverage of GTV at the assumed level of statistical confidence. Our results generalize earlier recommendations for statistical, central limit theorem-based recommendations for margin construction that were derived for uncorrelated distributions of errors (van Herk, Remeijer, Rasch and Lebesque 2000 Int. J. Radiat. Oncol. Biol. Phys. 47 1121-35 Stroom, De Boer, Huizenga and Visser 1999 Int. J. Radiat. Oncol. Biol. Phys. 43 905-19).

Papiez, Lech; Langer, Mark

2006-08-01

142

Music therapy CD creation for initial pediatric radiation therapy: a mixed methods analysis.  

PubMed

A mixed methods research design was used to investigate the effects of a music therapy CD (MTCD) creation intervention on pediatric oncology patients' distress and coping during their first radiation therapy treatment. The music therapy method involved children creating a music CD using interactive computer-based music software, which was "remixed" by the music therapist-researcher to extend the musical material. Eleven pediatric radiation therapy outpatients aged 6 to 13 years were randomly assigned to either an experimental group, in which they could create a music CD prior to their initial treatment to listen to during radiation therapy, or to a standard care group. Quantitative and qualitative analyses generated multiple perceptions from the pediatric patients, parents, radiation therapy staff, and music therapist-researcher. Ratings of distress during initial radiation therapy treatment were low for all children. The comparison between the two groups found that 67% of the children in the standard care group used social withdrawal as a coping strategy, compared to 0% of the children in the music therapy group; this trend approached significance (p = 0.076). MTCD creation was a fun, engaging, and developmentally appropriate intervention for pediatric patients, which offered a positive experience and aided their use of effective coping strategies to meet the demands of their initial radiation therapy treatment. PMID:21275334

Barry, Philippa; O'Callaghan, Clare; Wheeler, Greg; Grocke, Denise

2010-01-01

143

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

SciTech Connect

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.

Krema, Hatem, E-mail: htmkrm19@yahoo.com [Department of Ocular Oncology, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada)] [Department of Ocular Oncology, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada); Heydarian, Mostafa [Department of Radiation Medicine, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada)] [Department of Radiation Medicine, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada); Beiki-Ardakani, Akbar [Department of Radiation Oncology, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada)] [Department of Radiation Oncology, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada); Weisbrod, Daniel [Department of Ocular Oncology, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada)] [Department of Ocular Oncology, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada); Xu, Wei [Department of Biostatistics, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada)] [Department of Biostatistics, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada); Laperriere, Normand J.; Sahgal, Arjun [Department of Radiation Oncology, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada)] [Department of Radiation Oncology, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario (Canada)

2013-07-01

144

Mixed messages? A comparison between the perceptions of radiation therapy patients and radiation therapists regarding patients' educational needs  

Microsoft Academic Search

ObjectivesThe purpose of this study was to discover and compare radiation therapy patients' and radiation therapists' perceptions of patients' educational topics of interest and methods of information delivery during a course of radiation therapy.

Amanda Bolderston

2008-01-01

145

Optimal selection of beam orientations in intensity-modulated radiation therapy  

Microsoft Academic Search

Radiation therapy is a common and important treatment for some specific tumors in the treatment of cancer. In recent years, there has been a new development in radiation therapy, intensity-modulated radiation therapy (IMRT). IMRT modulates the intensity of the radiation beam to focus a higher radiation dose on the tumor while minimizing radiation exposure to surrounding normal tissues. This study

Ue-Pyng Wen; Ru-Siou Yu; Che-Wei Tsui

2011-01-01

146

OPTIMIZING THE SCENARIO POSITIONS FOR ROBUST RADIATION THERAPY TREATMENT PLANNING  

E-print Network

OPTIMIZING THE SCENARIO POSITIONS FOR ROBUST RADIATION THERAPY TREATMENT PLANNING Albin FREDRIKSSON Stockholm, Sweden. E-mail: albfre@kth.se and albin.fredriksson@raysearchlabs.com. Optimization and Systems

Forsgren, Anders

147

Intensity Modulated Beam Radiation Therapy Dose Optimization with Multiobjective  

E-print Network

Intensity Modulated Beam Radiation Therapy Dose Optimization with Multiobjective Evolutionary of Medical Physics and Engineering, Strahlenklinik, Klinikum Offenbach, 63069 Offenbach, Germany. 2 Medical Physics Department, Medical School, Patras University, 3 Institute of Communication and Computer Systems

Coello, Carlos A. Coello

148

Dynamic optimization of fractionation schedules in radiation therapy  

E-print Network

In this thesis, we investigate the improvement in treatment effectiveness when dynamically optimizing the fractionation scheme in radiation therapy. In the first part of the thesis, we consider delivering a different dose ...

Ramakrishnan, Jagdish

2013-01-01

149

Influence of Sampling in Radiation Therapy Treatment Design  

Microsoft Academic Search

\\u000a Computer-based optimization simulations have made significant contributions to the improvement of intensity modulated radiation\\u000a therapy (IMRT) treatment planning. Large amounts of data are typically involved in radiation therapy optimization problems.\\u000a Regardless the formulation used, the problem size is always the biggest challenge to overcome. The most common strategy to\\u000a address this problem is sampling which may have a significant impact

Humberto Rocha; Joana Dias; Brigida C. Ferreira; Maria do Carmo Lopes

150

Persistence of endometrial activity after radiation therapy for cervical carcinoma  

SciTech Connect

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.

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

1985-12-01

151

Results of conservative surgery and radiation therapy for breast cancer  

Microsoft Academic Search

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

R. T. Osteen; B. L. Smith

1990-01-01

152

A Shape Relationship Descriptor for Radiation Therapy Planning  

E-print Network

A Shape Relationship Descriptor for Radiation Therapy Planning Michael Kazhdan1 , Patricio Simari1 the design of patient treatment plans in radio- therapy. To this end we propose a novel shape descriptor for such tasks by outperform- ing state of the art shape descriptors in the retrieval of patients with similar

Kazhdan, Michael

153

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

SciTech Connect

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.

Wong, Sharon [National University of Singapore, Yong Loo Lin School of Medicine (Singapore); Back, Michael [Northern Sydney Cancer Centre, Royal North Shore Hospital, St Leonards, New South Wales (Australia); Tan, Poh Wee; Lee, Khai Mun; Baggarley, Shaun [National University, Cancer Institute, Department of Radiation Oncology, National University, Hospital, Tower Block (Singapore); Lu, Jaide Jay, E-mail: mdcljj@nus.edu.sg [National University of Singapore, Yong Loo Lin School of Medicine (Singapore); National University, Cancer Institute, Department of Radiation Oncology, National University, Hospital, Tower Block (Singapore)

2012-07-01

154

Radiation therapy among atomic bomb survivors, Hiroshima and Nagasaki.  

PubMed

As a follow-up to the two previous surveys of radiation therapy among the atomic bomb survivors, a large-scale survey was performed to document (1) the number of radiation therapy treatments received by the atomic bomb survivors and (2) the types of radiation treatments conducted in Hiroshima and Nagasaki. The previous two surveys covered the radiation treatments among the Radiation Effects Research Foundation Adult Health Study (AHS) population, which is composed of 20,000 persons. In the present survey, the population was expanded to include the Life Span Study (LSS), including 93,611 atomic bomb survivors and 26,517 Hiroshima and Nagasaki citizens who were not in the cities at the times of the bombings. The LSS population includes the AHS population. The survey was conducted from 1981 to 1984. The survey teams reviewed all the medical records for radiation treatments of 24,266 patients at 11 large hospitals in Hiroshima and Nagasaki. Among them, the medical records for radiation treatments of 1556 LSS members were reviewed in detail. By analyzing the data obtained in the present and previous surveys, the number of patients receiving radiation therapy was estimated to be 4501 (3.7%) in the LSS population and 1026 (5.1%) in the AHS population between 1945-1980. During 1945-1965, 98% of radiation treatments used medium-voltage X rays, and 66% of the treatments were for benign diseases. During 1966-1980, 94% of the radiation treatments were for malignant neoplasms. During this period, 60Co gamma-ray exposure apparatus and high-energy electron accelerators were the prevalent mode of treatment in Hiroshima and in Nagasaki, respectively. The mean frequency of radiation therapy among the LSS population was estimated to have been 158 courses/year during 1945-1965 and 110 courses/year during 1966-1980. The present survey revealed that 377 AHS members received radiation therapy. The number was approximately twice the total number of cases found in the previous two surveys. Thus the data on radiation therapy in the AHS members have been updated well by this survey, and will provide information for more precise dose-response analyses of radiation effects in the AHS population. The information extracted from the medical records of the hospitals consisted of hospital names, treatment periods, body sites treated, diagnoses, treatment doses, radiation sources, the field sizes of the exposures and the data for identification of the patients. These data will be essential in estimating the organ doses from scattered radiation and in evaluating the effects of therapeutic radiation. PMID:9611100

Kato, K; Antoku, S; Russell, W J; Fujita, S; Pinkston, J A; Hayabuchi, N; Hoshi, M; Kodama, K

1998-06-01

155

Large deformation 3D image registration in image-guided radiation therapy  

E-print Network

Large deformation 3D image registration in image-guided radiation therapy Mark Foskey, Brad Davis processing of serial 3D CT images used in image- guided radiation therapy. A major assumption in deformable-guided radiation therapy 2 1. Introduction In radiation cancer therapy, the problem of organ motion over the course

Utah, University of

156

Radiation therapy of pediatric brain tumors : comparison of long-term health effects and costs between proton therapy and IMRT  

E-print Network

Radiation therapy is an important component of pediatric brain tumor treatment. However, radiation-induced damage can lead to adverse long-term health effects. Proton therapy has the ability to reduce the dose delivered ...

Vu, An T. (An Thien)

2011-01-01

157

Cranial Radiation Therapy and Damage to Hippocampal Neurogenesis  

ERIC Educational Resources Information Center

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…

Monje, Michelle

2008-01-01

158

Late effects of radiation therapy on the gastrointestinal tract  

Microsoft Academic Search

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

Lawrence R. Coia; Robert J. Myerson; Joel E. Tepper

1995-01-01

159

Image-Guidance for Stereotactic Body Radiation Therapy  

SciTech Connect

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

Fuss, Martin [Department of Radiation Medicine, Oregon Health and Science University, Portland, OR (United States) and Department of Radiation Oncology, University of Texas Health Science Center at San Antonio, San Antonio, TX (United States) and Cancer Therapy and Research Center, San Antonio, TX (United States)]. E-mail: fussm@ohsu.edu; Boda-Heggemann, Judit [Department of Radiation Oncology, Mannheim Medical Center, University of Heidelberg, Mannheim (Germany); Papanikolau, Nikos [Department of Radiation Oncology, University of Texas Health Science Center at San Antonio, San Antonio, TX (United States); Cancer Therapy and Research Center, San Antonio, TX (United States); Salter, Bill J. [Department of Radiation Oncology, University of Utah, Salt Lake City, UT (United States); Huntsman Cancer Institute, Salt Lake City, UT (United States)

2007-07-01

160

Guidelines for respiratory motion management in radiation therapy  

PubMed Central

Respiratory motion management (RMM) systems in external and stereotactic radiotherapies have been developed in the past two decades. Japanese medical service fee regulations introduced reimbursement for RMM from April 2012. Based on thorough discussions among the four academic societies concerned, these Guidelines have been developed to enable staff (radiation oncologists, radiological technologists, medical physicists, radiotherapy quality managers, radiation oncology nurses, and others) to apply RMM to radiation therapy for tumors subject to respiratory motion, safely and appropriately. PMID:23239175

Matsuo, Yukinori; Onishi, Hiroshi; Nakagawa, Keiichi; Nakamura, Mitsuhiro; Ariji, Takaki; Kumazaki, Yu; Shimbo, Munefumi; Tohyama, Naoki; Nishio, Teiji; Okumura, Masahiko; Shirato, Hiroki; Hiraoka, Masahiro

2013-01-01

161

Cancer Pain Emergencies: Is There a Role for Radiation Therapy?  

Microsoft Academic Search

Emergent cancer pain is a difficult entity to manage. Radiation therapy potentially may be used for its treatment. Several\\u000a key issues must be addressed in patients with emergent cancer pain before initiating radiation. These issues include whether\\u000a the necessary diagnostic information is available, whether the tumor will respond rapidly to radiation, and whether there\\u000a are additional patient factors that will

Lindsay Sales; Jason K. Rockhill

2010-01-01

162

A Column Generation Approach to Radiation Therapy Treatment Planning Using Aperture Modulation  

Microsoft Academic Search

This paper considers the problem of radiation therapy treatment planning for cancer patients. During radiation therapy, beams of radiation pass through a patient. This radiation kills both cancerous and normal cells, so the radiation therapy must be carefully planned to deliver a clinically prescribed dose to certain targets while sparing nearby organs and tissues. Currently, a technique called intensity modulated

H. Edwin Romeijn; Ravindra K. Ahuja; James F. Dempsey; Arvind Kumar

2005-01-01

163

Prototype demonstration of radiation therapy planning code system  

SciTech Connect

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.

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

1996-09-01

164

Planning and delivery of intensity-modulated radiation therapy  

SciTech Connect

Intensity modulated radiation therapy (IMRT) is an advanced form of external beam radiation therapy. IMRT offers an additional dimension of freedom as compared with field shaping in three-dimensional conformal radiation therapy because the radiation intensities within a radiation field can be varied according to the preferences of locations within a given beam direction from which the radiation is directed to the tumor. This added freedom allows the treatment planning system to better shape the radiation doses to conform to the target volume while sparing surrounding normal structures. The resulting dosimetric advantage has shown to translate into clinical advantages of improving local and regional tumor control. It also offers a valuable mechanism for dose escalation to tumors while simultaneously reducing radiation toxicities to the surrounding normal tissue and sensitive structures. In less than a decade, IMRT has become common practice in radiation oncology. Looking forward, the authors wonder if IMRT has matured to such a point that the room for further improvement has diminished and so it is pertinent to ask what the future will hold for IMRT. This article attempts to look from the perspective of the current state of the technology to predict the immediate trends and the future directions. This article will (1) review the clinical experience of IMRT; (2) review what we learned in IMRT planning; (3) review different treatment delivery techniques; and finally, (4) predict the areas of advancements in the years to come.

Yu, Cedric X.; Amies, Christopher J.; Svatos, Michelle [Department of Radiation Oncology, University of Maryland School of Medicine, 22 South Greene Street, Baltimore, Maryland 21201 (United States); Siemens Medical Solutions USA, Inc., Oncology Care Systems Group, 4040 Nelson Avenue, Concord, California 94520 (United States); Translational Research, Varian Medical Systems, 3100 Hansen Way M/S E263 Palo Alto, California 94304-1038 (United States)

2008-12-15

165

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

MedlinePLUS

... back of this sheet to order the Radiation Therapy Side Effects Sheets that can help you the most. Revised ... livehelp NCI has a series of 9 Radiation Therapy Side Effects Sheets at: www.cancer.gov/radiation-side-effects ...

166

[The development of radiation necrosis of the brain after radiation therapy].  

PubMed

Examination by questionnaire of 102 institutions utilizing radiation therapy throughout the country revealed 97 cases of radiation necrosis of the brain, 41 cases of which have received only one course of radiation therapy with either high energy x-rays or 60Co gamma-rays and that have been histologically confirmed for necrosis. The dose fractionation relationship causing necrosis presumed by Strandquvist's diagram proved to be located along the line with the slope of 0.44 from the interception of 9.9 Gy with a single irradiation. Our own experience of brain tumor and cancer of the paranasal sinus told 2 with developed necrosis (incidence, 0.6%) of 325 cases on radiation therapy at a dose of 50-60 Gy and 5 (incidence, 2.0%) of 253 cases on radiation therapy at a dose of more than 60 Gy. PMID:3669308

Miyauchi, T; Ono, Y; Jingu, K; Morita, K

1987-08-01

167

Wayne State University Radiation Therapy Technology  

E-print Network

Standards Required of Professional Students Purpose of This Document Radiation Therapists are highly skilled the activities radiation therapists are expected to perform on a daily basis. Additionally, the Program wishes requirement that a therapist may encounter. If you have any questions or concerns about the required abilities/skills

Cinabro, David

168

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)

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.

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

2012-04-01

169

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

SciTech Connect

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.

Montes, J.G.

1983-01-01

170

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

SciTech Connect

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.

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

1987-12-01

171

Postmastectomy radiation therapy: an overview for the practicing surgeon.  

PubMed

Locoregional control of breast cancer is the shared domain and responsibility of surgeons and radiation oncologists. Because surgeons are often the first providers to discuss locoregional control and recurrence risks with patients and because they serve in a key gatekeeping role as referring providers for radiation therapy, a sophisticated understanding of the evidence regarding radiotherapy in breast cancer management is essential for the practicing surgeon. This paper synthesizes the complex and evolving evidence regarding the role of radiation therapy after mastectomy. Although substantial evidence indicates that radiation therapy can reduce the risk of locoregional failure after mastectomy (with a relative reduction of risk of approximately two-thirds), debate persists regarding the specific subgroups who have sufficient risks of residual microscopic locoregional disease after mastectomy to warrant treatment with radiation. This paper reviews the evidence available to guide appropriate referral and patient decision making, with special attention to areas of controversy, including patients with limited nodal disease, those with large tumors but negative nodes, node-negative patients with high risk features, patients who have received systemic chemotherapy in the neoadjuvant setting, and patients who may wish to integrate radiation therapy with breast reconstruction surgery. PMID:24109522

Jagsi, Reshma

2013-01-01

172

Optimization under uncertainty in radiation therapy  

E-print Network

In the context of patient care for life-threatening illnesses, the presence of uncertainty may compromise the quality of a treatment. In this thesis, we investigate robust approaches to managing uncertainty in radiation ...

Chan, Timothy Ching-Yee

2007-01-01

173

Progress and controversies: Radiation therapy for prostate cancer.  

PubMed

Answer questions and earn CME/CNE Radiation therapy remains a standard treatment option for men with localized prostate cancer. Alone or in combination with androgen-deprivation therapy, it represents a curative treatment and has been shown to prolong survival in selected populations. In this article, the authors review recent advances in prostate radiation-treatment techniques, photon versus proton radiation, modification of treatment fractionation, and brachytherapy-all focusing on disease control and the impact on morbidity. Also discussed are refinements in the risk stratification of men with prostate cancer and how these are better for matching patients to appropriate treatment, particularly around combined androgen-deprivation therapy. Many of these advances have cost and treatment burden implications, which have significant repercussions given the prevalence of prostate cancer. The discussion includes approaches to improve value and future directions for research. CA Cancer J Clin 2014;64:389-407. © 2014 American Cancer Society. PMID:25234700

Martin, Neil E; D'Amico, Anthony V

2014-11-01

174

Stereotactic Body Radiation Therapy: Brachytherapy Perspective  

Microsoft Academic Search

\\u000a Brachytherapy was conceptualized in the early 1900s when Pierre Curie suggested that a small radium tube could be inserted\\u000a directly into cancer. Experiments carried out at that time showed tumor shrinkage in response to the directed radiation. The\\u000a first therapeutic brachytherapy treatments used surface molds to deliver low dose rate (LDR) radiation to skin cancers, and\\u000a by 1903 the first

Caroline L. Holloway; Desmond O’Farrell; Phillip M. Devlin

175

Advances in veterinary radiation therapy: targeting tumors and improving patient comfort.  

PubMed

Newer technology, such as intensity-modulated radiation therapy, can dramatically decrease acute radiation side effects, making patients more comfortable during and after treatment. Stereotactic radiation therapy for definitive treatment can be delivered in 1 to 5 fractions, with minimal radiation-associated effects. Image-guided radiation therapy can be used to direct treatment in locations previously not amenable to radiation therapy. Traditional fractionated radiation therapy remains the most commonly available type in veterinary medicine and is the standard of care for many tumors. This article discusses the role of advancements in the treatment of veterinary cancer patients and reviews more traditional radiation treatment. PMID:25174907

LaRue, Susan M; Custis, James T

2014-09-01

176

Brain Abscess Formation in Radiation Necrosis of the Temporal Lobe Following Radiation Therapy for Nasopharyngeal Carcinoma  

Microsoft Academic Search

Summary  ¶?Background. Radiation necrosis is a known complication following radiation therapy for extracranial as well as intracranial tumours.\\u000a However, brain abscess formation in radiation necrosis has not been reported in the literature. We report the clinical data\\u000a of 6 patients suffering from this condition.\\u000a \\u000a ?Method. Twenty-eight patients with radiation necrosis of the temporal lobe following radiotherapy for nasopharyngeal carcinoma were\\u000a treated

K.-M. Cheng; C.-M. Chan; Y.-T. Fu; L.-C. Ho; Y.-W. Tsang; M.-K. Lee; Y.-L. Cheung; C.-K. Law

2000-01-01

177

Predicting Radiation Pneumonitis After Stereotactic Ablative Radiation Therapy in Patients Previously Treated With Conventional Thoracic Radiation Therapy  

SciTech Connect

Purpose: To determine the incidence of and risk factors for radiation pneumonitis (RP) after stereotactic ablative radiation therapy (SABR) to the lung in patients who had previously undergone conventional thoracic radiation therapy. Methods and Materials: Seventy-two patients who had previously received conventionally fractionated radiation therapy to the thorax were treated with SABR (50 Gy in 4 fractions) for recurrent disease or secondary parenchymal lung cancer (T <4 cm, N0, M0, or Mx). Severe (grade {>=}3) RP and potential predictive factors were analyzed by univariate and multivariate logistic regression analyses. A scoring system was established to predict the risk of RP. Results: At a median follow-up time of 16 months after SABR (range, 4-56 months), 15 patients had severe RP (14 [18.9%] grade 3 and 1 [1.4%] grade 5) and 1 patient (1.4%) had a local recurrence. In univariate analyses, Eastern Cooperative Oncology Group performance status (ECOG PS) before SABR, forced expiratory volume in 1 second (FEV1), and previous planning target volume (PTV) location were associated with the incidence of severe RP. The V{sub 10} and mean lung dose (MLD) of the previous plan and the V{sub 10}-V{sub 40} and MLD of the composite plan were also related to RP. Multivariate analysis revealed that ECOG PS scores of 2-3 before SABR (P=.009), FEV1 {<=}65% before SABR (P=.012), V{sub 20} {>=}30% of the composite plan (P=.021), and an initial PTV in the bilateral mediastinum (P=.025) were all associated with RP. Conclusions: We found that severe RP was relatively common, occurring in 20.8% of patients, and could be predicted by an ECOG PS score of 2-3, an FEV1 {<=}65%, a previous PTV spanning the bilateral mediastinum, and V{sub 20} {>=}30% on composite (previous RT+SABR) plans. Prospective studies are needed to validate these predictors and the scoring system on which they are based.

Liu Hui; Zhang Xu [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Vinogradskiy, Yevgeniy Y. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Swisher, Stephen G. [Department of Thoracic and Cardiovascular Surgery, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Thoracic and Cardiovascular Surgery, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Komaki, Ritsuko [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chang, Joe Y., E-mail: jychang@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2012-11-15

178

Enhanced radiation therapy with internalized polyelectrolyte modified nanoparticles.  

PubMed

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. PMID:25032891

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

2014-09-01

179

Enhanced radiation therapy with internalized polyelectrolyte modified nanoparticles  

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

180

The Use of Medical Images in Planning and Delivery of Radiation Therapy  

Microsoft Academic Search

The authors provide a survey of how images are used in radiation therapy to improve the precision of radiation therapy plans, and delivery of radiation treatment. In contrast to diagnostic radiology, where the focus is on interpretation of the images to decide if disease is present, radiation therapy quantifies the extent of the region to be treated, and relates it

Ira J Kalet; Mary M Austin-Seymour

1997-01-01

181

Using intraoperative radiation therapy--a case study.  

PubMed

The introduction of a mobile linear accelerator in the OR has made intraoperative radiation therapy (IORT) more plausible. An IORT treatment can deliver a single high dose of radiation to a tumor or tumor bed after surgical resection or surgical exposure of high risk areas. This article details a case study in which IORT was used on a patient with sigmoid carcinoma and the procedure outcomes. PMID:12619854

Domanovic, Mary Ann; Ouzidane, Malika; Ellis, Rod J; Kinsella, Timothy J; Beddar, A Sam

2003-02-01

182

Department of Medical Imaging and Radiation Sciences Short Course in Imaging for Advanced Radiation Therapy Practice  

E-print Network

Therapy Practice · Academic units must be studied concurrently or as a pre-requisite to studying clinical) Principles of Imaging for Advanced Radiation Therapy Practice 1 (Academic Unit) Duration 13 weeks Delivery as relevant to the role of the imaging advanced practitioner, such as CT, MRI, PET and Ultrasound, and more

Albrecht, David

183

Quality assurance in radiation therapy: physical aspects  

Microsoft Academic Search

The present status of the quality assurance work regarding the physical aspects in radiation treatment is discussed. In particular, the situation in Europe is surveyed. An analysis of the errors in the delivered absorbed dose to a specified point in the irradiated patient shows that the uncertainty, to approximately the same degree, depends on the dose distribution determination, the dose

Hans Svensson

1984-01-01

184

Radiation therapy for soft tissue sarcoma.  

PubMed

Sarcomas are relatively uncommon tumors of mesenchymal origin. They may arise anywhere within the musculoskeletal system and are typically classified by clinical behavior into benign, borderline, or malignant. This article focuses primarily on the role of radiation for malignant soft tissue sarcoma and selected borderline tumors. PMID:12916463

Ballo, Matthew T; Zagars, Gunar K

2003-04-01

185

CHRONIC LYMPHOCYTIC LEUKEMIA AND RADIATION THERAPY  

Microsoft Academic Search

One hundred and fifty cases of chronic lymphocytic leukemia seen from ; 1922 through 1960 were analyzed. The average age of the males was 56 years and ; of the females 58.4 years, giving a general age of 56.7 years. The amount of ; roentgen radiation delivered and the various survival times were studied, and it ; is definitely shown

J. C. Cook; W. Romano

1962-01-01

186

Late Gastrointestinal Toxicities Following Radiation Therapy for Prostate Cancer  

PubMed Central

Background Radiation therapy is commonly used to treat localized prostate cancer; however, representative data regarding treatment-related toxicities compared with conservative management are sparse. Objective To evaluate gastrointestinal (GI) toxicities in men treated with either primary radiation or conservative management for T1–T2 prostate cancer. Design, setting, and participants We performed a population-based cohort study, using Medicare claims data linked to the Surveillance Epidemiology and End Results data. Competing risk models were used to evaluate the risks. Measurements GI toxicities requiring interventional procedures occurring at least 6 mo after cancer diagnosis. Results and limitations Among 41 737 patients in this study, 28 088 patients received radiation therapy. The most common GI toxicity was GI bleeding or ulceration. GI toxicity rates were 9.3 per 1000 person-years after three-dimensional conformal radiotherapy, 8.9 per 1000 person-years after intensity-modulated radiotherapy, 5.3 per 1000 person-years after brachytherapy alone, 20.1 per 1000 person-years after proton therapy, and 2.1 per 1000 person-years for conservative management patients. Radiation therapy is the most significant factor associated with an increased risk of GI toxicities (hazard ratio [HR]: 4.74; 95% confidence interval [CI], 3.97–5.66). Even after 5 yr, the radiation group continued to experience significantly higher rates of new GI toxicities than the conservative management group (HR: 3.01; 95% CI, 2.06–4.39). Because our cohort of patients were between 66 and 85 yr of age, these results may not be applicable to younger patients. Conclusions Patients treated with radiation therapy are more likely to have procedural interventions for GI toxicities than patients with conservative management, and the elevated risk persists beyond 5 yr. PMID:21684064

Kim, Sung; Shen, Shunhua; Moore, Dirk F.; Shih, Weichung; Lin, Yong; Li, Hui; Dolan, Matthew; Shao, Yu-Hsuan; Lu-Yao, Grace L.

2011-01-01

187

The effects of sequence and type of chemotherapy and radiation therapy on cosmesis and complications after breast conservation therapy  

Microsoft Academic Search

Purpose|: Chemotherapy plays an increasingly important role in the treatment of both node-negative and node-positive positive breast cancer partients, but the optimal sequencing of chemotherapy and radiation therapy is not well established. The purpose of this study is to evaluate the interaction of sequence and type of chemotherapy and hormonal therapy given with radiation therapy on the cosmetic outcome and

Deborah A. Markiewicz; Delray J. Schultz; Jonathan A. Haas; Eleanor E. R. Harris; Kevin R. Fox; John H. Glick; Lawrence J. Solin

1996-01-01

188

Phototherapy cabinet for ultraviolet radiation therapy  

SciTech Connect

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.

Horwitz, S.N.; Frost, P.

1981-08-01

189

A guide to design of radiation therapy facilities.  

PubMed

The design technique outline provides the information needed to develop a layout for a new or renovated radiation therapy department. The department described is a medium-sized facility with two megavoltage linear accelerators and a single simulator. The plans for an expansion to include another linear accelerator and a neutron generator also are presented. PMID:10270908

Galvin, J M; Claytor, N; Cedrone, B; Graff, R L

1985-01-01

190

Roadmap: Radiologic Imaging Sciences -Radiation Therapy (with AAS Radiologic Technology)  

E-print Network

and Physiology II for Allied Health (3) or BSCI 20020 Biological Structure and Function (5) 5-6 Fulfills KentRoadmap: Radiologic Imaging Sciences - Radiation Therapy (with AAS Radiologic Technology) ­ Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-RTAA] Regional College Catalog Year

Sheridan, Scott

191

Massive osteolysis of the right clavicle developing after radiation therapy  

Microsoft Academic Search

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

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

1988-01-01

192

Factors influencing radiation therapy student clinical placement satisfaction  

PubMed Central

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.

Bridge, Pete; Carmichael, Mary-Ann

2014-01-01

193

MRI in Radiation Therapy Planning: The Use of Ultrashort  

E-print Network

of a number of cancers. The radiation therapy planning process is currently based on a CT- scan of the patient at risk more accurate. It requires that the information from CT can be estimated from MRI. Conventional into CT images. Visualisation of compact bone is however made possible with a newly installed MRI sequence

194

Acute parotitis and hyperamylasemia following whole-brain radiation therapy  

SciTech Connect

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.

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

1980-04-01

195

Pediatric urological complications with intraoperative radiation therapy  

SciTech Connect

Intraoperative radiotherapy with variable energy electrons has been used as a supplemental boost to treat 6 children with locally advanced retroperitoneal malignancies. Of the patients 4 had treatment-related injuries to portions of the urinary tract within the intraoperative and external radiation fields. Three patients had significant renal impairment requiring surgical correction. The pathogenesis and management of treatment-induced injury to the urinary tract are discussed.

Ritchey, M.L.; Gunderson, L.L.; Smithson, W.A.; Kelalis, P.P.; Kaufman, B.H.; Telander, R.L.; Evans, R.G.; Kramer, S.A. (Mayo Clinic, Rochester, MN (USA))

1990-01-01

196

Inflammation and Plaque Vulnerability  

Microsoft Academic Search

Development of a thrombus at the site of an atherosclerotic plaque initiates abrupt arterial occlusion and is the proximate\\u000a event responsible for the vast majority of acute ischemic syndromes. In nearly 75% of cases thrombus overlies a disrupted\\u000a or ruptured plaque whereas the remainder of the thrombi overly an intact plaque with superficial endothelial erosion. Over\\u000a the past several years,

Prediman K. Shah

2009-01-01

197

Radiation therapy for liver tumors: ready for inclusion in guidelines?  

PubMed

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

Tanguturi, Shyam K; Wo, Jennifer Y; Zhu, Andrew X; Dawson, Laura A; Hong, Theodore S

2014-08-01

198

Complementary strategies for the management of radiation therapy side effects.  

PubMed

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

Stubbe, Christine E; Valero, Meighan

2013-07-01

199

Complementary Strategies for the Management of Radiation Therapy Side Effects  

PubMed Central

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

Stubbe, Christine E.; Valero, Meighan

2013-01-01

200

The Application of FLUKA to Dosimetry and Radiation Therapy  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

201

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

PubMed Central

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

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

2013-01-01

202

Selective internal radiation therapy: validation of intraoperative dosimetry.  

PubMed

In selective internal radiation (SIR) therapy of hepatic metastases, tumor vasculature is preferentially embolized with high-energy beta-emitting yttrium-90-labeled microspheres. To enable accurate estimation of the resultant absorbed radiation doses to tissues, an intraoperative beta detection probe is used to scan the liver surface. The validity of the response of this probe to Y-90 and its clinical application were assessed with a phantom containing varying activities and with biopsy samples obtained from patients being treated with SIR therapy. A linear relationship was found between the probe counts taken from the biopsy samples and the calculated tissue radiation doses from the specific activities of each sample. This relationship was repeated with probe counts determined against a water phantom containing various activities of Y-90. The probe was shown to respond minimally to bremsstrahlung. The use of the probe in measuring tissue radiation doses at laparotomy provides the opportunity to control dose administration during SIR therapy. In this way, subtherapeutic exposure of normal tissue can be assured while tumor tissue receives maximal radiation levels. PMID:2315490

Burton, M A; Gray, B N; Kelleher, D K; Klemp, P F

1990-04-01

203

Review and uses of stereotactic body radiation therapy for oligometastases.  

PubMed

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

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

2012-01-01

204

QA in Radiation Therapy: The RPC Perspective  

NASA Astrophysics Data System (ADS)

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.

Ibbott, G. S.

2010-11-01

205

Managing Radiation Therapy Side Effects: What to Do When Your Mouth or Throat Hurts  

MedlinePLUS

... National Institutes of Health Managing Radiation Therapy Side Effects What To Do When Your Mouth or Throat ... help stop the pain? Managing Radiation Therapy Side Effects:What To Do When Your Mouth or Throat ...

206

Managing Radiation Therapy Side Effects: What Women Can Do about Changes in Sexuality and Fertility  

MedlinePLUS

Managing Radiation Therapy Side Effects U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Wh at Women ... my doctor before treatment.” Questions from women getting radiation therapy: What if I think I may be ...

207

Managing Radiation Therapy Side Effects: What Men Can Do about Changes in Sexuality and Fertility  

MedlinePLUS

... Cancer Institute Managing Radiation Therapy Side Effects What Men Can Do About Changes in Sexuality and Fertility “ ... back to talk with your doctor. Questions from men getting radiation therapy to the pelvic area: Will ...

208

Hepatocellular carcinoma radiation therapy: review of evidence and future opportunities.  

PubMed

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. PMID:23219567

Klein, Jonathan; Dawson, Laura A

2013-09-01

209

Hepatocellular Carcinoma Radiation Therapy: Review of Evidence and Future Opportunities  

SciTech Connect

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.

Klein, Jonathan [Department of Radiation Oncology, Princess Margaret Hospital/University of Toronto, Toronto, Ontario (Canada); Dawson, Laura A., E-mail: laura.dawson@rmp.uhn.on.ca [Department of Radiation Oncology, Princess Margaret Hospital/University of Toronto, Toronto, Ontario (Canada)

2013-09-01

210

NCI: SBIR & STTR - Find Funding - Contracts - 258 Innovative Devices to Protect Radiosensitive Organs and Structures During Radiation Therapy  

Cancer.gov

Radiation therapy is an important tool in the cancer treatment arsenal. More than one million patients undergo radiation therapy in the US each year. Recent improvements in radiation therapy instrumentation increased the clinical utility of this treatment modality.

211

Natural cytotoxicity in patients undergoing radiation therapy  

SciTech Connect

Natural cytotoxicity against K562 target cells was measured in 51 adults with solid epithelial malignant tumors who were untreated, in 42 patients who were studied within 6 weeks following completion of radiotherapy (4,000-7,000 rads), and in 27 normal subjects. In both the radiated and the nonirradiated groups, mean cytotoxicity for patients with localized cancers was not significantly different from that of the normal controls, whereas mean cytotoxicity for patients with advanced cancers was significantly lower than that for normal controls and patients with localized disease. Twelve percent of nonirradiated patients and 13% of radiated patients with localized tumors, but 46% of nonirradiated patients and 44% of irradiated patients with advanced cancers, failed to exhibit normal NK activity. Mean cytotoxicity for irradiated patients was not significantly different from that of untreated patients. PBL from most patients showed enhanced cytotoxicity after preincubation of PBL with interferon (IFN alpha). Mean cytotoxicities for nonirradiated and irradiated patients after IFN alpha pretreatment of PBL were not significantly different. In both patient groups, IFN alpha-boosted killing was significantly less in patients with advanced disease than in patients with local tumors or normals. These results indicated that radiotherapy has no significant effect on spontaneous or IFN alpha-boosted natural cytotoxicity.

Kadish, A.S.; Ghossein, N.A.

1983-02-01

212

Optimization of radiation therapy treatment planning  

SciTech Connect

Radiation oncology is a medical specialty which uses ionizing radiation to treat disease, usually cancer, with the goal being to produce the highest probability of tumor control with the least likelihood of causing complications in the surrounding organs. The process of choosing suitable combinations of treatment beams, each with appropriate shape, intensity, energy, and direction, has come to be called {open_quotes}treatment planning,{close_quotes} and it is an exercise in computer modeling. Recent advances in computer and treatment technology have made it possible to consider evaluate novel arrangements of beams and compute the pattern of dose which would result throughout the three dimensional volume of the patient. Evaluating the resulting mass of data is daunting, and so algorithms for optimizing beam selection are urgently needed. This presentation reviews the optimization techniques which have been applied to the problem, starting from the earliest effort in the late 1960`s. Linear programming, quadratic programming, and random search methods such as simulated annealing have all been developed by different research groups. This presentation reviews the most promising efforts reported and suggests possible areas for additional research.

Ezzell, G.

1994-12-31

213

Dose to normal tissues outside the radiation therapy patient's treated volume: a review of different radiation therapy techniques.  

PubMed

Radiation therapy treatment planning and delivery capabilities have changed dramatically since the introduction of three-dimensional treatment planning and are continuing to change relatively rapidly in response to the implementation of new advanced technologies. Three-dimensional conformal radiation therapy (3DCRT) is now firmly in place as the standard of practice in clinics around the world. Medical accelerator manufacturers have employed advanced computer technology to produce treatment planning/delivery systems capable of precise shaping of dose distributions via computer-controlled multileaf collimator (MLC) systems, by which the beam fluence is varied optimally to achieve the desired dose distribution. This mode of conformal therapy is referred to as intensity modulated radiation therapy (IMRT), and is capable of generating dose distributions (including concave isodose volumes) that closely conform the prescription dose to the target volume and/or avoid specific sensitive normal structures. The increasing use of IMRT has focused attention on the need to better account for the intra- and inter-fraction spatial uncertainties in the dose delivery process. This has helped spur the development of treatment machines with integrated planar and volumetric advanced imaging capabilities, providing a new treatment modality referred to as image-guided IMRT (IG-IMRT), or simply image-guided radiation therapy (IGRT). In addition, there is a growing interest in replacing x rays with protons because of the physical characteristics of the depth dose curve, which peaks at the end of particle range, and eventually with even heavier charged particles to take advantage of the greater density of energy deposition close to the Bragg peak and hence larger relative biological effectiveness (RBE). Three-dimensional CRT, IMRT and proton beam therapy all provide improved target coverage and lower doses to surrounding normal tissues as compared to the previously used two-dimensional radiation therapy techniques. However, this is achieved at the expense of a greater volume of normal tissue in the irradiated volume receiving some dose and a higher whole body dose (or peripheral dose) to distant normal tissues. The higher whole body dose is a result of the increased x-ray leakage radiation to the patient due to the longer beam-on times associated with IMRT, and also from neutron leakage radiation associated with high energy x-ray beams (>10 MV) and proton beams. Dose distributions for the various CRT techniques and the current status of available data for normal tissues, and whole body dose are reviewed. PMID:18849701

Purdy, James A

2008-11-01

214

Ionizing Radiation Response Effects On Optical Fibers In Radiation Therapy Dosimetry Applications  

NASA Astrophysics Data System (ADS)

Radiation effects on optical fibers result in two different bffects: accumulated radiation damage resulting in a substantial loss of transmission and transient radiation response in which light is generated in the fiber material itself during exposure .too radiation. In various medical applications, optical fibers are often exposed to radiation during certain clinical procedures which makes their radiation response an effect of concern to the medical community. Thus, this effect needs to be studied and quantified in that kind of environment. This study involves radiation-resistant fibers and the quantification of their light emission response as a function of dose rate and irradiation field size for photon and electron beams at the various energises used in radiation therapy.

Beddar, Abdou-Samad; Higgins, Patrick D.

1989-04-01

215

Stereotactic Body Radiation Therapy in Spinal Metastases  

SciTech Connect

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.

Ahmed, Kamran A. [Mayo Medical School, College of Medicine, Mayo Clinic, Rochester, MN (United States); Stauder, Michael C.; Miller, Robert C.; Bauer, Heather J. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Rose, Peter S. [Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN (United States); Olivier, Kenneth R. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Brown, Paul D. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Brinkmann, Debra H. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Laack, Nadia N., E-mail: laack.nadia@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States)

2012-04-01

216

Radiation therapy: state of the art and the future.  

PubMed

Technical innovation in radiation therapy (RT) such as stereotactic irradiation, intensity modulated RT, image-guided RT, and brachytherapy using remote controlled after-loading system have made it possible to deliver ideally distributed radiation dose to the target with great accuracy, while sparing the adjacent organs at risk. As a result, tumor control rate by RT improved markedly and became excellent alternative to surgery for asymptomatic or mildly symptomatic brain tumors, early stage lung cancer, and low-risk prostate cancer. In locally advanced stage of cancer, randomized controlled trials established the chemoradiation therapy as a standard treatment option for patients with head and neck cancer, lung cancer, esophageal cancer, and cervical cancer. RT is also a valuable treatment for palliation of local symptoms caused by cancer with consistently high response rates. Minimally invasive therapy has come to be emphasized its needs in the background of increased tendency of elderly patients with cancer, and advances in conformal dose delivery technique raise the RT at a more important position in cancer therapy. However, adequate number of RT profession is indispensable to utilize highly-sophisticated RT technology. Substantiality of an education system for radiation oncologist, RT technologist, and medical physicists is our current most important issue. PMID:20299738

Ikushima, Hitoshi

2010-02-01

217

Initiation of multileaf collimator conformal radiation therapy  

SciTech Connect

Clinical studies have been initiated in conformal radiotherapy using computer controlled multileaf collimator. Quantitative dosimetry and treatment planning studies comparing field shaping by lead alloy blocks and the multileaf collimator demonstrate the clinical acceptability of the multileaf collimator. Sixteen patients with tumors in multiple sites have received some part of their treatments with both blocking systems. Studies of dosimetry and field shaping show that the multileaf collimator produces clinically acceptable blocking for most field shapes and disease sites. The 80-20% penumbra was characterized for a wide range of shaped beams. For straight edges perpendicular to the leaf travel, the penumbra of measured dose distributions from the multileaf collimator is equal to conventional divergent blocking. When the multileaf collimator leaves approach a contour at an angle, the penumbra increases. At forty-five degrees, the maximum angle of approach, the penumbra is approximately 4 mm wider than that for divergent blocks. Three-dimensional treatment planning demonstrates that equivalent dose distributions can be obtained from the two field shaping systems. The multileaf collimator can be used effectively and efficiently to treat a variety of disease sites. Its optimal utility may be in treating complex fields - five or more shaped coplanar or non-coplanar beams. It is well suited for conformal therapy applications. 17 refs., 7 figs., 2 tabs.

Powlis, W.D.; Smith, A.R.; Cheng, E.; Galvin, J.M.; Villari, F.; Bloch, P.; Kligerman, M.M. (Hospital of the Univ. of Pennsylvania, Philadelphia (United States))

1993-01-15

218

Dose Escalation, Not "New Biology," Can Account for the Efficacy of Stereotactic Body Radiation Therapy With  

E-print Network

conformal radiation therapy (3D-CRT) for stage I non-small cell lung cancer (NSCLC), sheds light on the "new Radiation Therapy With Non-Small Cell Lung Cancer J. Martin Brown, PhD,* David J. Brenner, PhD,y and David J 14, 2012. Accepted for publication Nov 1, 2012 Stereotactic body radiation therapy (SBRT), also known

Brenner, David Jonathan

219

Clinical opportunities in combining immunotherapy with radiation therapy  

PubMed Central

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

Finkelstein, Steven E.; Fishman, Mayer

2012-01-01

220

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

SciTech Connect

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.

Kelly, Patrick [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Balter, Peter A. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Rebueno, Neal; Sharp, Hadley J.; Liao Zhongxing; Komaki, Ritsuko [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Chang, Joe Y., E-mail: jychang@mdanderson.or [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

2010-12-01

221

Gold nanoparticles and their alternatives for radiation therapy enhancement  

PubMed Central

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

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

2014-01-01

222

Radiation therapy in the treatment of metastatic renal cell carcinoma  

SciTech Connect

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.

Onufrey, V.; Mohiuddin, M.

1985-11-01

223

Shielding and Radiation Protection in Ion Beam Therapy Facilities  

NASA Astrophysics Data System (ADS)

Radiation protection is a key aspect of any radiotherapy (RT) department and is made even more complex in ion beam therapy (IBT) by the large facility size, secondary particle spectra and intricate installation of these centers. In IBT, large and complex radiation producing devices are used and made available to the public for treatment. It is thus the responsibility of the facility to put in place measures to protect not only the patient but also the general public, occupationally and nonoccupationally exposed personnel working within the facility, and electronics installed within the department to ensure maximum safety while delivering maximum up-time.

Wroe, Andrew J.; Rightnar, Steven

224

Impact of dose calculation algorithm on radiation therapy  

PubMed Central

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.

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

2014-01-01

225

Radiation therapy in the management of childhood brain tumors  

Microsoft Academic Search

Radiation therapy (RT) still plays a major role in the management of intracranial malignancies, together with surgical resection\\u000a and, more recently, chemotherapy. This is a review of the experience with fractionated external beam RT. In medulloblastomas,\\u000a combined modalities currently achieve a 5-year survival in excess of 70% in low-risk subgroups and 40% in the subgroups considered\\u000a to be high risk.

Jean-Louis Habrand; Renaud De Crevoisier

2001-01-01

226

Managing the cognitive effects of brain tumor radiation therapy  

Microsoft Academic Search

Opinion statement  Postoperative radiation therapy (RT), either alone or in combination with chemotherapy, is the mainstay of treatment for primary\\u000a and\\/or metastatic brain tumors. The majority of patients with brain tumors will have significant symptoms of their disease\\u000a and of RT that will have a negative impact on their quality of life and neurocognitive function. The symptoms of brain tumors\\u000a depend

Jerome M. Butler; Stephen R. Rapp; Edward G. Shaw

2006-01-01

227

Combination of vascular targeting agents with thermal or radiation therapy  

Microsoft Academic Search

Purpose: The most likely clinical application of vascular targeting agents (VTAs) is in combination with more conventional therapies. In this study, we report on preclinical studies in which VTAs were combined with hyperthermia and\\/or radiation.Methods and Materials: A C3H mammary carcinoma grown in the right rear foot of female CDF1 mice was treated when at 200 mm3 in size. The

Michael R Horsman; Rumi Murata

2002-01-01

228

ReVOLT: radiation-enhanced viral oncolytic therapy  

SciTech Connect

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.

Advani, Sunil J. [Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL (United States); Mezhir, James J. [Department of Surgery, University of Chicago, Chicago, IL (United States); Roizman, Bernard [Marjorie B. Kovler Viral Oncology Laboratories, University of Chicago, Chicago, IL (United States); Weichselbaum, Ralph R. [Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL (United States)]. E-mail: rrw@rover.uchicago.edu

2006-11-01

229

Carcinoma of the nasal vestibule treated with radiation therapy  

Microsoft Academic Search

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

NANCY P. MENDENHALL; JAMES T. PARSONS; NICHOLAS J. CASSISI; RODNEY R. MILLION

1987-01-01

230

The Tumor-Immune Microenvironment and Response to Radiation Therapy  

Microsoft Academic Search

Chemotherapy and radiation therapy (RT) are standard therapeutic modalities for patients with cancer, including breast cancer.\\u000a Historic studies examining tissue and cellular responses to RT have predominantly focused on damage caused to proliferating\\u000a malignant cells leading to their death. However, there is increasing evidence that RT also leads to significant alterations\\u000a in the tumor microenvironment, particularly with respect to effects

Stephen L. Shiao; Lisa M. Coussens

2010-01-01

231

Massive osteolysis of the right clavicle developing after radiation therapy  

SciTech Connect

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.

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

1988-07-15

232

A collaboratory for radiation therapy treatment planning optimization research  

Microsoft Academic Search

Intensity modulated radiation therapy treatment planning (IMRTP) is a challenging application of optimization technology.\\u000a We present software tools to facilitate IMRTP research by computational scientists who may not have convenient access to radiotherapy\\u000a treatment planning systems. The tools, developed within Matlab and CERR (computational environment for radiotherapy research),\\u000a allow convenient access, visualization, programmable manipulation, and sharing of patient treatment planning

Joseph Deasy; Eva K. Lee; T. Bortfeld; Mark P. Langer; K. Zakarian; J. Alaly; Y. Zhang; H. Liu; R. Mohan; R. Ahuja; A. Pollack; J. Purdy; Ronald L. Rardin

2006-01-01

233

Detection of High-Risk Atherosclerotic Plaque  

PubMed Central

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

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

234

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

The development of Alzheimer's disease (AD) is closely connected with cholesterol metabolism. Cholesterol increases the production and deposition of amyloid-? (A?) 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 A? 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 A? pathology in mouse models of AD. PMID:19654569

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

2009-01-01

235

CT evaluation of effects of cranial radiation therapy in children  

SciTech Connect

A retrospective evaluation was completed of 49 children who received conventional cranial radiation therapy for primary central nervous system and/or skull-base neoplasia and who had follow-up CT studies. In these children, abnormalities in normal parenchyma away from the tumor itself were surprisingly frequent, with or without chemotherapy. Generalized volume loss or atrophy was the most frequent abnormality (51%), but in this population it may have resulted from a variety of causes. Calcification in nontumorous parenchyma was common (28%) with or without chemotherapy. The most frequent site of calcification was subcortical at the gray-white junction. Calcification was progressive over 1-2 years and correlated pathologically with mineralizing microangiopathy and dystrophic calcification with demyelination. White-matter abnormalities other than those associated with shunt malfunction and tumor edema occurred in 26% of the patients. Both white-matter abnormalities and calcification occurred predominantly in younger children, particularly those under 3 years old at the time of radiation therapy. Of the 21 children who received chemotherapy in this series, only two received methotrexate. White-matter abnormalities and calcifications occurred with similar frequency in children with and without chemotherapy; thus, radiation therapy is the most likely cause of these findings.

Davis, P.C.; Hoffman, J.C. Jr.; Pearl, G.S.; Braun, I.F.

1986-09-01

236

Radiation therapy oncology group gynecologic oncology working group: comprehensive results.  

PubMed

The purpose of this report was to comprehensively describe the activities of the Gynecologic Oncology Working Group within the Radiation Therapy Oncology Group (RTOG). Clinical trials will be reviewed as well as translational science and ancillary activities. During the past 40 years, a myriad of clinical trials have been performed within the RTOG with the aim of improving overall survival (OS) and decreasing morbidity in women with cervical or endometrial cancer. Major study questions have included hyperbaric oxygen, neutron radiotherapy, altered fractionation, hypoxic cell sensitization, chemosensitization, and volume-directed radiotherapy.RTOG 7920 demonstrated improvement in OS in patients with stages IB through IIB cervical carcinoma receiving prophylactic para-aortic irradiation compared to pelvic radiation alone. RTOG 9001 demonstrated that cisplatin and 5-FU chemoradiotherapy to the pelvis for advanced cervix cancer markedly improved OS compared to extended field radiotherapy alone. More recent trials have used radioprotectors, molecular-targeted therapy, and intensity-modulated radiation therapy. Ancillary studies have developed clinical target volume atlases for research protocols and routine clinical use. Worldwide practice patterns have been investigated in cervix, endometrial, and vulvar cancer through the Gynecologic Cancer Intergroup. Translational studies have focused on immunohistochemical markers, changes in gene expression, and miRNA patterns impacting prognosis.The RTOG gynecologic working group has performed clinical trials that have defined the standard of care, improved survival, and added to our understanding of the biology of cervical and endometrial cancers. PMID:24819663

Gaffney, David K; Jhingran, Anuja; Portelance, Lorraine; Viswanathan, Akila; Schefter, Tracey; Weidhaas, Joanne; Small, William

2014-06-01

237

Adaptive radiation therapy of prostate cancer  

NASA Astrophysics Data System (ADS)

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

Wen, Ning

238

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

PubMed Central

Introduction 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. Methods 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. Results 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. Conclusion 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.

Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham

2013-01-01

239

Medical factors influencing decision making regarding radiation therapy for breast cancer  

PubMed Central

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

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

240

Aesthetic results following partial mastectomy and radiation therapy  

SciTech Connect

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.

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

1990-05-01

241

Brachytherapy with an improved MammoSite Radiation Therapy System  

NASA Astrophysics Data System (ADS)

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.

Karthik, Nanda; Keppel, Cynthia; Nazaryan, Vahagn

2007-03-01

242

Androgen Deprivation Therapy Toxicity and Management for Men Receiving Radiation Therapy  

PubMed Central

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

Johnson, Matthew E.; Buyyounouski, Mark K.

2012-01-01

243

Water equivalent plastic scintillation detectors in radiation therapy.  

PubMed

A review of the dosimetric characteristics and properties of plastic scintillation detectors for use in radiation therapy is presented. The detectors show many desirable qualities when exposed to megavoltage photon and electron beams, including water equivalence, energy independence, reproducibility, dose linearity, resistance to radiation damage and near temperature independence. These detectors do not require the usual conversion and/or correction factors used to convert the readings from common dosemeters to absorbed dose. Due to their small detecting volume, plastic scintillation detectors exhibit excellent spatial resolution. Detector performance, in certain specific cases, can be affected by radiation-induced light arising in the optical fibres that carry the scintillator signal to a photodetector. While this effect is negligible for photon beams, it may not be ignored for electron beams and needs to be accounted for. PMID:16882685

Beddar, A S

2006-01-01

244

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

SciTech Connect

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.

Valicenti, Richard K., E-mail: Richard.valicenti@ucdmc.ucdavis.edu [Department of Radiation Oncology, University of California, Davis School of Medicine, Davis, California (United States); Thompson, Ian [Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, Texas (United States); Albertsen, Peter [Division of Urology, University of Connecticut Health Center, Farmington, Connecticut (United States); Davis, Brian J. [Department of Radiation Oncology, Mayo Medical School, Rochester, Minnesota (United States); Goldenberg, S. Larry [Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia (Canada); Wolf, J. Stuart [Department of Urology, University of Michigan, Ann Arbor, Michigan (United States); Sartor, Oliver [Department of Medicine and Urology, Tulane Medical School, New Orleans, Louisiana (United States); Klein, Eric [Glickman Urological Kidney Institute, Cleveland Clinic, Cleveland, Ohio (United States); Hahn, Carol [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Michalski, Jeff [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States); Roach, Mack [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Faraday, Martha M. [Four Oaks, Inc (United States)

2013-08-01

245

Docetaxel and radiation as combined-modality therapy.  

PubMed

Combined-modality approaches for the treatment of non-small-cell lung cancer (NSCLC), head and neck cancer, and esophageal cancer offer survival benefits by improving locoregional control and treating micrometastatic disease. The taxanes are active, tolerable drugs in these solid tumors and have radiation-sensitizing activity. Docetaxel (Taxotere) has been studied in combination with radiation with favorable results. In phase II trials, docetaxel combined with radiation therapy resulted in response rates of up to 80%, with the most commonly used schedule being docetaxel at 20 to 30 mg/m2 per week with concomitant radiation administered at fractions of 1.8 to 2.0 Gy, 5 days a week over 5 to 6 weeks. Studies of docetaxel and platinum combinations have been conducted predominantly in patients with NSCLC. Early results show good activity and acceptable toxicity, with esophagitis or mucositis being dose-limiting. Doses of docetaxel at 20 mg/m2 per week combined with cisplatin at 25 mg/m2 or carboplatin (Paraplatin) at an area under the concentration-time curve (AUC) of 2 with concomitant radiation appear to be well tolerated and active. Future investigations, including phase III trials in patients with locally advanced NSCLC, are encouraged. Current trials are studying various design schedules, including induction chemotherapy with radiation followed by consolidation chemotherapy. PMID:12108904

Kim, Edward S; Khuri, Fadlo R

2002-06-01

246

Intraoperative phosphorus-32 brachytherapy plaque for multiply recurrent high-risk epidural neuroblastoma.  

PubMed

Achieving local control is a crucial component in the management of neuroblastoma, but this may be complicated in the setting of prior radiation treatment, especially when the therapeutic target is in proximity to critical structures such as the spinal cord. The authors describe a pediatric patient with multiply recurrent neuroblastoma and prior high-dose radiation therapy to the spine who presented with progressive epidural disease. The patient was managed with resection and intraoperative high-dose-rate brachytherapy using a phosphorus-32 ((32)P) plaque previously developed for the treatment of brain and spine lesions. PMID:24483253

Tong, William Y; Folkert, Michael R; Greenfield, Jeffrey P; Yamada, Yoshiya; Wolden, Suzanne L

2014-04-01

247

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

SciTech Connect

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).

Lingos, T.I.; Recht, A.; Vicini, F.; Abner, A.; Silver, B.; Harris, J.R. (Joint Center for Radiation Therapy, Harvard Medical School, Boston, MA (USA))

1991-07-01

248

Anonymization of DICOM electronic medical records for radiation therapy.  

PubMed

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

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

2014-10-01

249

High Field Atherosclerotic Plaque MRI  

PubMed Central

Manifestations of atherosclerotic plaque in different arterial beds range from perfusion deficits to overt ischemia such as stroke and myocardial infarction. Atherosclerotic plaque composition is known to be associated with its propensity to rupture and cause vascular events. MRI of atherosclerotic plaque using clinical 1.5T scanners can detect plaque composition. Plaque MRI at higher field strengths offers both opportunities and challenges to improving the high spatial-resolution and contrast required for this type of imaging. This article summarizes the technological requirements required for high field plaque MRI and its application in detecting plaque components. PMID:22548932

Yuan, Chun; Wang, Jinnan; Balu, Niranjan

2012-01-01

250

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

SciTech Connect

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.

Hannan, Raquibul, E-mail: Raquibul.Hannan@gmail.com [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States)] [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Thompson, Reid F.; Chen Yu; Bernstein, Karen; Kabarriti, Rafi; Skinner, William [Department of Radiation Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York (United States)] [Department of Radiation Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York (United States); Chen, Chin C. [Department of Radiation Oncology, Columbia University Medical Center, New York, New York (United States)] [Department of Radiation Oncology, Columbia University Medical Center, New York, New York (United States); Landau, Evan; Miller, Ekeni; Spierer, Marnee; Hong, Linda; Kalnicki, Shalom [Department of Radiation Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York (United States)] [Department of Radiation Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York (United States)

2012-11-15

251

Overview of Radiation Therapy for Treating Rectal Cancer  

PubMed Central

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.

Kye, Bong-Hyeon

2014-01-01

252

A macropencil beam model: clinical implementation for conformal and intensity modulated radiation therapy  

E-print Network

-centre fields in advanced treatment techniques, particularly intensity modulated radiation therapy, has strained therapy This article has been downloaded from IOPscience. Please scroll down to see the full text article for conformal and intensity modulated radiation therapy Mark H Phillips, Karen M Singer and Alan R Hounsell

Yetisgen-Yildiz, Meliha

253

The New Radiation Therapy Clinical Practice: The Emerging Role of Clinical Peer Review for Radiation Therapists and Medical Dosimetrists  

Microsoft Academic Search

The concept of peer review for radiation therapists and medical dosimetrists has been studied very little in radiation oncology practice. The purpose of this manuscript is to analyze the concept of peer review in the clinical setting for both radiation therapists and medical dosimetrists. The literature reviewed both the percentages and causes of radiation therapy deviations. The results indicate that

Robert D. Adams; Lawrence B. Marks; Todd Pawlicki; James Hayman; Jessica Church

2010-01-01

254

Accuracy of Marketing Claims by Providers of Stereotactic Radiation Therapy  

PubMed Central

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

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

2013-01-01

255

Evaluation of selection criteria for graduate students in radiation therapy.  

PubMed

Selection of suitable students into graduate medical and specialist health professional courses can be difficult. Historically, selection of students was primarily based on prior academic performance. Recently, however, more emphasis has been placed on considering broader academic backgrounds and personal characteristics and attitudes of students, but no reliable measurement tool is available to predict student success and satisfaction with their choice of profession. The aim of this study was to survey practising radiation therapists in Australia to seek their opinions regarding suitable selection criteria for graduate entry radiation therapy (RT) students in order to optimize selection procedures for future applicants. Four hundred questionnaires were sent to nine RT centres in three states within Australia. All nine clinics participated in the survey and 189 questionnaires were returned. Results show that the majority of radiation therapists place a high level of importance upon a sound knowledge of physics and mathematics, as well as life experience, and agree that a visit to an RT clinic plus an interview comprise important components of the selection process. Humanities, psychology and a psychometric test were not viewed as essential entry requirements. Experienced radiation therapists placed less value on academic performance in the primary degree and were more likely to include an interview as a selection criterion than junior practitioners. Empathy for patients was identified as the most important personal attribute. It is thus recommended that not only cognitive but also personal skills be evaluated during the selection of prospective radiation therapists. PMID:17594574

Schneider-Kolsky, Michal; Wright, Caroline; Baird, Marilyn

2006-12-01

256

Regorafenib-induced transverse myelopathy after stereotactic body radiation therapy  

PubMed Central

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.

Tian, Sibo; Nissenblatt, Michael

2014-01-01

257

Peripheral Doses from Noncoplanar IMRT for Pediatric Radiation Therapy  

SciTech Connect

The use of noncoplanar intensity-modulated radiation therapy (IMRT) might result in better sparing of some critical organs because of a higher degree of freedom in beam angle optimization. However, this can lead to a potential increase in peripheral dose compared with coplanar IMRT. The peripheral dose from noncoplanar IMRT has not been previously quantified. This study examines the peripheral dose from noncoplanar IMRT compared with coplanar IMRT for pediatric radiation therapy. Five cases with different pediatric malignancies in head and neck were planned with both coplanar and noncoplanar IMRT techniques. The plans were performed such that the tumor coverage, conformality, and dose uniformity were comparable for both techniques. To measure the peripheral doses of the 2 techniques, thermoluminescent dosimeters (TLD) were placed in 10 different organs of a 5-year-old pediatric anthropomorphic phantom. With the use of noncoplanar beams, the peripheral doses to the spinal cord, bone marrow, lung, and breast were found to be 1.8-2.5 times of those using the coplanar technique. This is mainly because of the additional internal scatter dose from the noncoplanar beams. Although the use of noncoplanar technique can result in better sparing of certain organs such as the optic nerves, lens, or inner ears depending on how the beam angles were optimized on each patient, oncologists should be alert of the possibility of significantly increasing the peripheral doses to certain radiation-sensitive organs such as bone marrow and breast. This might increase the secondary cancer risk to patients at young age.

Kan, Monica W.K., E-mail: kanwkm@ha.org.h [Department of Oncology, Princess Margaret Hospital, University of Hong Kong (Hong Kong); Leung, Lucullus H.T. [Department of Oncology, Princess Margaret Hospital, University of Hong Kong (Hong Kong); Kwong, Dora L.W. [Department of Clinical Oncology, Queen Mary Hospital, University of Hong Kong (Hong Kong); Wong, Wicger; Lam, Nelson [Department of Oncology, Princess Margaret Hospital, University of Hong Kong (Hong Kong)

2010-01-01

258

A Method for Evaluating Quality Assurance Needs in Radiation Therapy  

SciTech Connect

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.

Huq, M. Saiful [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA (United States)], E-mail: huqs@upmc.edu; Fraass, Benedick A. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI (United States); Dunscombe, Peter B. [Department of Medical Physics, Tom Baker Cancer Center, Calgary, AB (Canada); Gibbons, John P. [Department of Medical Physics, Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Ibbott, Geoffrey S. [Radiological Physics Center, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Medin, Paul M. [Department of Radiation Oncology, Nebraska Medical Center, Omaha, NE (United States); Mundt, Arno [Department of Radiation Oncology, University of California-San Diego, San Diego, CA (United States); Mutic, Sassa [Department of Radiation Oncology, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Palta, Jatinder R. [Department of Radiation Oncology, University of Florida, Gainesville, FL (United States); Thomadsen, Bruce R. [Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Williamson, Jeffrey F. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA (United States); Yorke, Ellen D. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2008-05-01

259

Change in Seroma Volume During Whole-Breast Radiation Therapy  

SciTech Connect

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.

Sharma, Rajiv [Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY (United States); Spierer, Marnee [Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY (United States)], E-mail: mspierer@montefiore.org; Mutyala, Subhakar; Thawani, Nitika [Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY (United States); Cohen, Hillel W. [Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY (United States); Hong, Linda; Garg, Madhur K.; Kalnicki, Shalom [Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY (United States)

2009-09-01

260

Radiation Therapy Planning: an Uncommon Application of Lisp Ira J. Kalet, Robert S. Giansiracusa, Craig Wilcox, and Matthew Lease  

E-print Network

Radiation Therapy Planning: an Uncommon Application of Lisp Ira J. Kalet, Robert S. Giansiracusa, Craig Wilcox, and Matthew Lease Department of Radiation Oncology and Department of Computer Science interactive graphics simulation system called \\Prism", for planning radiation therapy. Special features

Yetisgen-Yildiz, Meliha

261

Optimization of radiation therapy. II. The critical-voxel model  

SciTech Connect

The Complication Factor (CF) is an objective function recently introduced for use in the optimization of radiation therapy treatment planning. Unlike earlier objective functions based upon physical/geometrical criteria, such as tumor dose uniformity, minimal integral-dose, etc., the CF stems from a simple biological/probabilistic model of radiation damage in living organisms. The CF defines the integral-response of an organ as that fraction of it rendered non-functional by irradiation. This approach does not work, however, if complications in any one individual volume-element are critical, as with spinal cord or tumor recurrence. Several authors have addressed the later problem, and we find that the probabilistic argument common to their methods fits comfortably within the CF framework. Drawing attention to the distinct differences between the integral-response and critical-voxel cases hopefully will be of value in the further development of biological modelling, for application in radiotherapy and elsewhere.

Wolbarst, A.B.

1984-05-01

262

Fast Monte Carlo for radiation therapy: the PEREGRINE Project  

SciTech Connect

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.

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

263

Radiation Plus Hormone Therapy for Locally Advanced Prostate Cancer Improves Survival  

Cancer.gov

Clinical trial results published online December 15, 2009, in The Lancet, affirms earlier studies showing that adding radiation therapy to hormone therapy (HT) is more effective than HT alone for locally advanced prostate cancer.

264

Potency preservation following stereotactic body radiation therapy for prostate cancer  

PubMed Central

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

2013-01-01

265

Mechanisms Involved in Radiation Enhancement of Intratumoral Dendritic Cell Therapy  

PubMed Central

We have previously reported that local tumor irradiation, without inducing cell death, can augment the therapeutic efficacy of intratumoral (i.t.) dendritic cell (DC) vaccination. This study examined potential mechanisms underlying radiation enhancement of i.t. DC therapy in this setting. Even though ionizing radiation did not mediate tumor cell kill, bone marrow-derived DCs acquired in vitro tumor antigens from irradiated D5 murine melanoma cells more efficiently than from untreated cells. This radiation-enhanced loading of DCs did not induce DC maturation, but was associated with improved cross-priming of T cells both in vitro and in vivo. Furthermore, in vivo pulsing of DCs with irradiated versus untreated tumor cells resulted in superior presentation of tumor antigens to T cells. In addition, tumor irradiation facilitated homing of i.t. administered DCs to the draining lymph node, possibly by down-regulating CCL21 expression within the tumor mass. Studies of the tumor microenvironment in irradiated versus untreated tumors did not reveal significant inflammatory changes. Moreover, radiation did not promote accumulation of CD4+ or CD8+ effector T cells within solid tumors. Our results indicate that, without inducing cytotoxicity, tumor irradiation can enhance the ability of DCs to capture tumor antigens, migrate to the draining lymph node, and present processed antigens to T cells. These findings may prove useful in designing future strategies for human cancer immunotherapy. PMID:18391761

Teitz-Tennenbaum, Seagal; Li, Qiao; Okuyama, Ryuji; Davis, Mary A.; Sun, Rong; Whitfield, Joel; Knibbs, Randall N.; Stoolman, Lloyd M.; Chang, Alfred E.

2011-01-01

266

Internal dosimetry for radiation therapy in coronary arteries.  

PubMed

Acute myocardial infarction, which occurs because of the occlusion of one or more coronary arteries, is the most common form of cardiovascular disease. Balloon angioplasty is often used to treat coronary artery occlusion and is less invasive than surgery involving revascularisation of the myocardium, thus promising a better quality of life for patients. Unfortunately, the rate of re-stenosis after balloon angioplasty is high (approximately 30-50% within the first year after treatment). Intravascular radiation therapy has been used with several types of radiation source, and researchers have observed some success in decreasing the rate of re-stenosis. In this paper theoretical radiation dose distributions for monoenergetic electrons (with discrete energies) and photons are calculated for blood vessels of diameter 1.5, 3.0 and 4.5 mm with balloon and wire sources using the radiation transport code MCNP4B. Stent sources employing 32P are also simulated. Advantages and disadvantages of the radionuclides and source geometries are discussed, as well as issues regarding possible benefits to the patients. PMID:12382782

Compos, L; Stabin, M

2002-01-01

267

Intensity-modulated radiation therapy and image-guided radiation therapy: small clinic implementation.  

PubMed

In a small clinic with a small patient base, the implementation of IMRT/IGRT should be slow, measured, and meticulous. Most radiation oncologists in the United States have had no formal training in IMRT/IGRT because the modalities are so new. Proper patient selection and a team effort among the clinician, physicist, dosimetrist, and therapist are thus all the more critical. The clinician in the small clinic can take comfort in remembering that the technologies are new, but the principles of good radiation medicine are not. With patient selection, a team approach, and publication of data and maturation of the literature, IMRT/IGRT will become the new standard of care in academic centers, large private clinics, and small clinics alike. PMID:16580557

Ting, Joseph Y; Scarbrough, Todd J

2006-02-01

268

Limited-Field Radiation Therapy in the Management of Early-Stage Breast Cancer  

Microsoft Academic Search

Background: Several phase III trials have demonstrated equivalent long-term survival between breast conserving surgery plus radiation therapy and mastectomy in patients with early-stage breast cancer but have not provided infor- mation on the optimal volume of breast tissue requiring post-lumpectomy radiation therapy. Therefore, we exam- ined the 5-year results of a single institution's experience with radiation therapy limited to the

Frank A. Vicini; Larry Kestin; Peter Chen; Pamela Benitez; Neal S. Goldstein; Alvaro Martinez

2003-01-01

269

Quality Assurance Procedures for Stereotactic Body Radiation Therapy  

SciTech Connect

Cranial stereotactic radiosurgery (SRS) and radiotherapy (SRT) are established treatment modalities. Initial implementations of these techniques rigidly attached frames to the patient's head for single-fraction treatments. The head frame accommodates an external fiducial marker system that is a reliable reference for targets within the cranium and accurately links the imaging equipment used for treatment planning to the treatment device. Fractionated SRT treatments use noninvasive 'relocatable'-type head immobilization that fixes to the patient's head and face features. Clearly defined quality assurance (QA) procedures exist for both cranial SRS and SRT but are not as well developed for extracranial SRT. Procedures for demonstrating the geometric relationship between the planning imaging and treatment have to some degree copied the techniques used for intracranial stereotactic irradiation. However, there are some unique QA issues that are specific to extracranial irradiation. One major consideration is the large number of methodologies available for stereotactic body radiation therapy. In addition to the variety of integrated image-guided frameless systems, there are immobilization devices (called body frame systems) that use a fiducial reference system similar to the cranial devices. This article describes generic QA approaches that can be adapted to the various stereotactic body radiation therapy methodologies.

Galvin, James M. [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania (United States)], E-mail: james.galvin@jeffersonhospital.org; Bednarz, Greg [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania (United States)

2008-05-01

270

Intraluminal radiation therapy in the management of malignant biliary obstruction  

SciTech Connect

Fifteen patients with malignant biliary obstruction from carcinoma of the bile ducts, gallbladder, and pancreas (Group I) or metastatic disease (Group II) were treated with intraluminal radiation therapy (ILRT) at Memorial Sloan-Kettering Cancer Center. In 11 cases ILRT was used as a central boost in combination with 3000 cGy external beam radiation therapy (ERT). No significant treatment toxicity was observed. Cholangiographic response was observed in 2 of 12 evaluable patients. In no patient was long-term relief of jaundice without indwelling biliary stent achieved. Survival from treatment in eight Group I patients treated with ILRT +/- ERT was 3 to 13 months (median, 4.5). Survival in seven similarly treated Group II patients was 0.5 to 8 months (median, 4.0). Additional data for ten similar patients referred for ILRT but treated with ERT alone are presented. Analysis of this and other reports indicate the need for prospective controlled trials of the role of this regimen in the management of malignant biliary obstruction before wider application can be recommended.

Molt, P.; Hopfan, S.; Watson, R.C.; Botet, J.F.; Brennan, M.F.

1986-02-01

271

Quality assurance procedures for stereotactic body radiation therapy.  

PubMed

Cranial stereotactic radiosurgery (SRS) and radiotherapy (SRT) are established treatment modalities. Initial implementations of these techniques rigidly attached frames to the patient's head for single-fraction treatments. The head frame accommodates an external fiducial marker system that is a reliable reference for targets within the cranium and accurately links the imaging equipment used for treatment planning to the treatment device. Fractionated SRT treatments use noninvasive "relocatable"-type head immobilization that fixes to the patient's head and face features. Clearly defined quality assurance (QA) procedures exist for both cranial SRS and SRT but are not as well developed for extracranial SRT. Procedures for demonstrating the geometric relationship between the planning imaging and treatment have to some degree copied the techniques used for intracranial stereotactic irradiation. However, there are some unique QA issues that are specific to extracranial irradiation. One major consideration is the large number of methodologies available for stereotactic body radiation therapy. In addition to the variety of integrated image-guided frameless systems, there are immobilization devices (called body frame systems) that use a fiducial reference system similar to the cranial devices. This article describes generic QA approaches that can be adapted to the various stereotactic body radiation therapy methodologies. PMID:18406909

Galvin, James M; Bednarz, Greg

2008-01-01

272

Outcome and Prognostic Factors of Radiation Therapy for Medulloblastoma  

SciTech Connect

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.

Rieken, Stefan, E-mail: Stefan.Rieken@med.uni-heidelberg.de [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Mohr, Angela; Habermehl, Daniel; Welzel, Thomas; Lindel, Katja [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Witt, Olaf; Kulozik, Andreas E. [Department of Pediatric Oncology, Hematology, Immunology, and Pneumatology, University of Heidelberg, Heidelberg (Germany); Wick, Wolfgang [Department of Neurooncology, University of Heidelberg, Heidelberg (Germany); Debus, Juergen; Combs, Stephanie E. [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany)

2011-11-01

273

Protons to replace photons in external beam radiation therapy?  

PubMed

Protons provide the basis for superior distribution of radiation dose due to the physical characteristics of protons. Proton beams used in radiation therapy can be designed to yield a uniform dose across the target and then virtually zero deep to the target and lower dose proximal to the target (for non-superficial lesions). Such beams can be employed in comparable number, direction, weighting, angulation, intensity modulation as is feasible for photon beams. The result is a smaller treatment volume, and hence a lower incidence and frequency of treatment-related morbidity. Importantly, the reduction in treatment volume permits a higher dose to the tumour. This means an improved tumour control probability and lower normal tissue complication probability. Clinical gains appear to have been realized in the treatment of patient with uveal melanoma, skull-base sarcoma, para-nasal sinus carcinomas, selected stages of lung carcinoma and hepatocellular carcinoma. There are now three proton therapy centres with gantry systems with seven more being built. Further, there are seven additional centres in active planning. At present, prospective clinical evaluations are in progress for tumours at many anatomical sites. PMID:12602561

Suit, H D

2003-02-01

274

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

SciTech Connect

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.

Driewer, Joseph P.; Chen, Haijian; Osvet, Andres; Low, Daniel A.; Li, H. Harold [Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, Missouri 63110 and Nuclear Science and Engineering Institute, University of Missouri, E4431 Lafferre Hall, Columbia, Missouri 65211 (United States); Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, Missouri 63110 (United States); Department of Materials Science and Engineering, Friedrich-Alexander-University Erlangen-Nuremberg, Martensstrasse 7, Erlangen 91058 (Germany); Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, Missouri 63110 (United States)

2011-08-15

275

Hyperbaric Oxygen Therapy for Radiation-Induced Cystitis and Proctitis  

SciTech Connect

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.

Oliai, Caspian; Fisher, Brandon; Jani, Ashish; Wong, Michael; Poli, Jaganmohan; Brady, Luther W. [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States); Komarnicky, Lydia T., E-mail: lydia.komarnicky-kocher@drexelmed.edu [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)

2012-11-01

276

Surgical and radiation therapy management of recurrent anal melanoma  

PubMed Central

Background Melanoma of the anorectal mucosa is a rare but highly aggressive tumor. Its presenting symptoms are frequently confused with hemorrhoids, thereby causing a delay in diagnosis. Anorectal melanoma carries with it a very poor prognosis. There is a paucity of data investigating management options for anorectal melanoma, and even fewer data reporting recurrent or refractory cases. Case presentation This case documents a 41-year-old female with a long history of hemorrhoids presenting with anorectal discharge. She was incidentally found have anorectal melanoma following surgical resection. Systemic diagnostic work-up demonstrated PET-avid lymphadenopathy in her right groin. She underwent right groin dissection. However, seven months later she recurred in her right groin and a new recurrent mass was found in her pelvis. She underwent a second groin dissection and resection of the pelvic recurrence. This was followed by a course of hypofractionated radiation therapy then systemic immunotherapy. Discussion Surgery has been the mainstay of treatment. However, the extent of surgery has been the topic of investigation. Historically, radical resections have been performed but they result in high rates of post-operative morbidity. Newer studies have compared radical resection with wide local excisions and found comparable outcomes. Anorectal melanoma is frequently a systemic disease. The ideal systemic therapy regimen has not yet been determined but numerous studies show a benefit to multi-agent treatments. Radiation therapy is typically given in the post-operative or palliative setting. Conclusions Anorectal mucosal melanoma is a very rare but aggressive disease with a poor prognosis. The overall treatment goal should strive to optimize quality of life and tumor control while minimizing treatment-related morbidities. PMID:24490051

Ling, Ted C.; Slater, Jason M.; Senthil, Maheswari; Kazanjian, Kevork; Howard, Frank; Garberoglio, Carlos A.; Slater, Jerry D.

2014-01-01

277

The New Radiation Therapy Clinical Practice: The Emerging Role of Clinical Peer Review for Radiation Therapists and Medical Dosimetrists  

SciTech Connect

The concept of peer review for radiation therapists and medical dosimetrists has been studied very little in radiation oncology practice. The purpose of this manuscript is to analyze the concept of peer review in the clinical setting for both radiation therapists and medical dosimetrists. The literature reviewed both the percentages and causes of radiation therapy deviations. The results indicate that peer review can be both implemented and evaluated into both the radiation therapist and medical dosimetrist clinical practice patterns.

Adams, Robert D.; Marks, Lawrence B. [UNC Department of Radiation Oncology, Chapel Hill, NC (United States); Pawlicki, Todd [Department of Radiation Oncology, University of California, San Diego, CA (United States); Hayman, James [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Church, Jessica, E-mail: jachurch@email.unc.ed [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States)

2010-01-01

278

The new radiation therapy clinical practice: the emerging role of clinical peer review for radiation therapists and medical dosimetrists.  

PubMed

The concept of peer review for radiation therapists and medical dosimetrists has been studied very little in radiation oncology practice. The purpose of this manuscript is to analyze the concept of peer review in the clinical setting for both radiation therapists and medical dosimetrists. The literature reviewed both the percentages and causes of radiation therapy deviations. The results indicate that peer review can be both implemented and evaluated into both the radiation therapist and medical dosimetrist clinical practice patterns. PMID:21055612

Adams, Robert D; Marks, Lawrence B; Pawlicki, Todd; Hayman, James; Church, Jessica

2010-01-01

279

Results of a Radiation Therapist Opinion Survey Identifying, Measuring and Addressing Radiation Therapy Patient Supportive Care Needs  

Microsoft Academic Search

Background: At Sunnybrook's Odette Cancer Centre, a multidisciplinary research team with expertise in radiation therapy and supportive care embarked on a comprehensive, evidence-based three-phase study, “Identifying, Measuring and Addressing Radiation Therapy Patient Supportive Care Needs at the Odette Cancer Centre.” The subject of this paper, a radiation therapist opinion survey, constitutes Phase I of that study.Purpose: The goal of Phase

John Maamoun; Margaret Fitch; Ruth Barker; Sheila Robson; Carol Gillies; Angela Turner; Irene Lange-Mechlen; Sandra Gardner; Alex Kiss

2009-01-01

280

A Survivin-Associated Adaptive Response in Radiation Therapy  

PubMed Central

Adaptive responses can be induced in cells by very low doses of ionizing radiation resulting in an enhanced resistance to much larger exposures. The inhibitor of apoptosis (IAP) protein, survivin, has been implicated in many adaptive responses to cellular stress. Computerized axial tomography (CAT) used in image guided radiotherapy to position and monitor tumor response utilizes very low radiation doses ranging from 0.5 to 100 mGy. We investigated the ability of these very low radiation doses administered along with two 2 Gy doses separated by 24 h, a standard conventional radiotherapy dosing schedule, to initiate adaptive responses resulting in the elevation of radiation resistance in exposed cells. Human colon carcinoma (RKO36), mouse sarcoma (SA-NH), along with transformed mouse embryo fibroblasts (MEF), wild type (WT) or cells lacking functional tumor necrosis factor receptors 1 and 2 (TNFR1?R2?) were used to assess their relative ability to express an adaptive response when grown either to confluence in vitro or as tumors in the flank of C57BL/6 mice. The survival of each of these cells was elevated from 5 to 20% (P ? 0.05) as compared to cells not receiving a 100 mGy or lesser dose. Additionally, the cells exposed to 100 mGy exhibited elevations in survivin levels, reductions in apoptosis frequencies, and loss of an adaptive response if transfected with survivin siRNA. This survivin-mediated adaptive response has the potential for affecting outcomes if regularly induced throughout a course of image guided radiation therapy. PMID:23651635

Grdina, David J.; Murley, Jeffrey S.; Miller, Richard C.; Mauceri, Helena J.; Sutton, Harold G.; Li, Jian Jian; Woloschak, Gayle E.; Weichselbaum, Ralph R.

2013-01-01

281

Hyperbaric Oxygen Therapy in Treating Long-Term Gastrointestinal Adverse Effects Caused by Radiation Therapy in Patients With Pelvic Cancer  

ClinicalTrials.gov

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

2011-07-14

282

Plastic scintillation dosimetry for radiation therapy: minimizing capture of Cerenkov radiation noise  

NASA Astrophysics Data System (ADS)

Over the last decade, there has been an increased interest in scintillation dosimetry using small water-equivalent plastic scintillators, because of their favourable characteristics when compared with other more commonly used detector systems. Although plastic scintillators have been shown to have many desirable dosimetric properties, as yet there is no successful commercial detector system of this type available for routine clinical use in radiation oncology. The main factor preventing this new technology from realizing its full potential in commercial applications is the maximization of signal coupling efficiency and the minimization of noise capture. A principal constituent of noise is Cerenkov radiation. This study reports the calculated capture of Cerenkov radiation by an optical fibre in the special case where the radiation is generated by a relativistic particle on the fibre axis and the fibre axis is parallel to the Cerenkov cone. The fraction of radiation captured is calculated as a function of the fibre core refractive index and the refractive index difference between the core and the cladding of the fibre for relativistic particles. This is then used to deduce the relative intensity captured for a range of fibre core refractive indices and fibre core-cladding refractive index differences. It is shown that the core refractive index has little effect on the amount of radiation captured compared to the refractive index difference. The implications of this result for the design of radiation therapy plastic scintillation dosimeters are considered.

Beddar, A. Sam; Suchowerska, Natalka; Law, Susan H.

2004-03-01

283

Plastic scintillation dosimetry for radiation therapy: minimizing capture of Cerenkov radiation noise.  

PubMed

Over the last decade, there has been an increased interest in scintillation dosimetry using small water-equivalent plastic scintillators, because of their favourable characteristics when compared with other more commonly used detector systems. Although plastic scintillators have been shown to have many desirable dosimetric properties, as yet there is no successful commercial detector system of this type available for routine clinical use in radiation oncology. The main factor preventing this new technology from realizing its full potential in commercial applications is the maximization of signal coupling efficiency and the minimization of noise capture. A principal constituent of noise is Cerenkov radiation. This study reports the calculated capture of Cerenkov radiation by an optical fibre in the special case where the radiation is generated by a relativistic particle on the fibre axis and the fibre axis is parallel to the Cerenkov cone. The fraction of radiation captured is calculated as a function of the fibre core refractive index and the refractive index difference between the core and the cladding of the fibre for relativistic particles. This is then used to deduce the relative intensity captured for a range of fibre core refractive indices and fibre core-cladding refractive index differences. It is shown that the core refractive index has little effect on the amount of radiation captured compared to the refractive index difference. The implications of this result for the design of radiation therapy plastic scintillation dosimeters are considered. PMID:15070202

Beddar, A Sam; Suchowerska, Natalka; Law, Susan H

2004-03-01

284

Treatment-related complications of radiation therapy after radical prostatectomy: comparative effectiveness of intensity-modulated versus conformal radiation therapy  

PubMed Central

Intensity-modulated radiation therapy (IMRT) is frequently utilized after prostatectomy without strong evidence for an improvement in outcomes compared to conformal radiation therapy (RT). We analyzed a large group of patients treated with RT after radical prostatectomy (RP) to compare complications after IMRT and CRT. The Surveillance, Epidemiology and End Results (SEER)-Medicare database was queried to identify male Medicare beneficiaries aged 66 years or older who underwent prostatectomy with 1+ adverse pathologic features and received postprostatectomy RT between 1995 and 2007. Chi-square test was used to compare baseline characteristics between the treatment groups. First complication events, based upon administrative procedure or diagnosis codes occurring >1 year after start of RT, were compared for IMRT versus CRT groups. Propensity score adjustment was performed to adjust for potential confounders. Multivariable Cox proportional hazards models of time to first complication were performed. A total of 1686 patients were identified who received RT after RP (IMRT = 634, CRT = 1052). Patients treated with IMRT were more likely to be diagnosed after 2004 (P < 0.001), have minimally invasive prostatectomy (P < 0.001) and have positive margins (P = 0.019). IMRT use increased over time. After propensity score adjustment, IMRT was associated with lower rate of gastrointestinal (GI) complications, and higher rate of genitourinary-incontinence complications, compared to CRT. The observed outcomes after IMRT must be considered when determining the optimal approach for postprostatectomy RT and warrant additional study. PMID:24519910

Crandley, Edwin F; Hegarty, Sarah E; Hyslop, Terry; Wilson, David D; Dicker, Adam P; Showalter, Timothy N

2014-01-01

285

Beneficial effect of combination hormonal therapy administered prior and following external beam radiation therapy in localized prostate cancer  

Microsoft Academic Search

Purpose: The aim of the present study isto investigate whether combined androgen blockade associated with radiation therapy for localized prostate cancer decreases at 12 and 24 months the rate of ppsitive follow-up biopsies and serum PSA compared to radiation therapy alone. This is the report of an interim analysis.Methods and Materials: One hundred and twenty patients with clinical Stage B1-T2a,

Jacques Laverdière; José L. Gomez; Leonelo Cusan; Elbio Raul Suburu; Pierre Diamond; Martin Lemay; Bernard Candas; André Fortin; Fernand Labrie

1997-01-01

286

Skeletal sequelae of radiation therapy for malignant childhood tumors  

SciTech Connect

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.

Butler, M.S.; Robertson, W.W. Jr.; Rate, W.; D'Angio, G.J.; Drummond, D.S. (UMDNJ Robert Wood Johnson Medical School, New Brunswick (USA))

1990-02-01

287

Compliance with Therapeutic Guidelines in Radiation Therapy Oncology Group Prospective Gastrointestinal Clinical Trials  

PubMed Central

Background This report analyzes the adherence to radiation therapy protocol guidelines in contemporary Radiation Therapy Oncology Group (RTOG) gastrointestinal trials. We aim to provide insight into current standards and compliance of radiation therapy field design and administration. Methods From 1994 to 2006, the Gastrointestinal Cancer Committee of the RTOG initiated and completed 15 phase I-III clinical trials utilizing radiation therapy in the multimodality treatment of gastrointestinal cancers. In each protocol, details for planning and executing radiation therapy were outlined and each protocol contained scoring criteria for these components of radiation therapy, characterized according to per-protocol, variation acceptable and deviation unacceptable. Review of treatment planning and implementation was performed in all studies following therapy completion. Results Radiation therapy planning and implementation was reviewed in 2,309 of 2,312 (99.9%) patients. The mean rate of compliance over all for the 15 protocols was 65% (total of the 2,309 analyzed patients). The mean variation acceptable rate was 21% whereas the mean deviation unacceptable rate was 5%. The mean “other” rate (no RT given or incomplete RT due to death, progression or refusal) was 8%. Two of the 15 trials (13%) had deviation unacceptable rates > 10%. In four studies incorporating pre-treatment review of radiation therapy planning and treatment, compliance with protocol therapy was enhanced. Conclusion The fidelity of radiation planning and execution detailed in protocol to actual therapy is heterogeneous, with a mean per-protocol rate of 65%. As clinical trials evolve, available technology should permit efficient pre-treatment review processes, thus facilitating compliance to protocol therapy. These analyses should also permit prospective analysis of outcome measures by compliance to therapy. PMID:23084596

Willett, Christopher G.; Moughan, Jennifer; O'Meara, Elizabeth; Galvin, James M.; Crane, Christopher H.; Winter, Kathryn; Manfredi, Denise; Rich, Tyvin A.; Rabinovitch, Rachel; Lustig, Robert; Machtay, Mitchell; Curran, Walter J

2014-01-01

288

Irradiated Esophageal Cells are Protected from Radiation-Induced Recombination by MnSOD Gene Therapy  

E-print Network

Irradiated Esophageal Cells are Protected from Radiation-Induced Recombination by MnSOD Gene. Irradiated Esophageal Cells are Protected from Radiation- Induced Recombination by MnSOD Gene Therapy. Radiat in esophageal cells. These results demonstrate the efficacy of MnSOD-PL for suppressing radiation-induced HR

Engelward, Bevin

289

Association between Randall's Plaque and Calcifying Nanoparticles  

NASA Technical Reports Server (NTRS)

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.

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

290

Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks  

NASA Technical Reports Server (NTRS)

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.

Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

2006-01-01

291

Intraoperative radiation therapy using mobile electron linear accelerators: report of AAPM Radiation Therapy Committee Task Group No. 72.  

PubMed

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

Beddar, A Sam; Biggs, Peter J; Chang, Sha; Ezzell, Gary A; Faddegon, Bruce A; Hensley, Frank W; Mills, Michael D

2006-05-01

292

[Equipment and positioning technologies in stereotactic body radiation therapy].  

PubMed

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

Marchesi, V; Dedieu, V; Lacornerie, T; Buchheit, I

2014-01-01

293

Low Level Laser Therapy: laser radiation absorption in biological tissues  

NASA Astrophysics Data System (ADS)

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.

Di Giacomo, Paola; Orlando, Stefano; Dell'Ariccia, Marco; Brandimarte, Bruno

2013-07-01

294

Radiation Therapy Oncology Group clinical trials with misonidazole  

SciTech Connect

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.

Wasserman, T.H. (Washington Univ., St. Louis, MO); Stetz, J.; Phillips, T.L.

1981-05-15

295

Implementation of Image-Guidance Techniques in Radiation Therapy  

NASA Astrophysics Data System (ADS)

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.

Thomas, Michael; Clark, Brenda; MacPherson, Miller; Montgomery, Lynn; Gerig, Lee

2008-06-01

296

Stereotactic body radiation therapy in pancreatic cancer: the new frontier.  

PubMed

Pancreatic cancer (PCA) remains a disease with a poor prognosis. The majority of PCA patients are unable to undergo surgical resection, which is the only potentially curative option at this time. A combination of chemotherapy and chemoradiation (CRT) are standard options for patients with locally advanced, unresectable disease, however, local control and patient outcomes remains poor. Stereotactic body radiation therapy (SBRT) is an emerging treatment option for PCA. SBRT delivers potentially ablative doses to the pancreatic tumor plus a small margin over a short period of time. Early studies with single-fraction SBRT demonstrated excellent tumor control with high rates of toxicity. The implementation of SBRT (3-5 doses) has demonstrated promising outcomes with favorable tumor control and toxicity rates. Herein we discuss the evolving role of SBRT in PCA treatment. PMID:25183386

Moningi, Shalini; Marciscano, Ariel E; Rosati, Lauren M; Ng, Sook Kien; Teboh Forbang, Roland; Jackson, Juan; Chang, Daniel T; Koong, Albert C; Herman, Joseph M

2014-12-01

297

Carcinoma of the nasal vestibule treated with radiation therapy  

SciTech Connect

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.

Mendenhall, N.P.; Parsons, J.T.; Cassisi, N.J.; Million, R.R.

1987-05-01

298

Stereotactic body radiation therapy for centrally-located lung tumors  

PubMed Central

The application of high-dose irradiation to centrally-located lung tumors is generally considered to be of high risk in causing bronchial injury. The aim of the present retrospective study was to investigate the safety and efficacy of stereotactic body radiation therapy (SBRT) for patients with centrally-located lung tumors. In total, 28 patients who underwent SBRT for lung tumors within 2 cm of a major bronchus were retrospectively analyzed. The median total dose prescribed was 45 Gy (range, 36.3–52.5 Gy), the median fraction was 12 (range, 10–15) and the median dose per fraction was 3.6 Gy (range, 3–5 Gy). The median follow-up period for the surviving patients was 14 months (range, 10–41 months). The local control rate of SBRT was 100%, with a complete response (CR) rate of 32.1% (9/28); a partial response (PR) rate of 50% (14/28) and a stable disease (SD) rate of 17.9% (5/28). In total, 15 patients survived and 13 patients succumbed; 11 patients succumbed to tumor progression, one to congestive heart failure and one to a brain hemorrhage. The main side-effects included grade 2 esophagitis (17.9%; 5/28) atelectasis (10.7%; 3/28) and grade 2 late radiation pneumonitis (7.1%; 2/28). Severe late toxicity (? grade 3) was not observed in any patient. SBRT is an effective and safe therapy for centrally-located lung tumors. PMID:24944711

SHEN, GE; WANG, YING-JIE; SHEN, WEN-JIANG; ZHOU, ZHEN-SHAN; WANG, JUN-LIANG; SHENG, HONG-GUO; DONG, DA-PENG; ZHOU, MING; YANG, GANG; WANG, QIN-WEN; ZENG, YANJUN

2014-01-01

299

Proton-minibeam radiation therapy: A proof of concept  

SciTech Connect

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.

Prezado, Y. [IMNC-UMR 8165, CNRS, Paris 7 and Paris 11 Universities, 15 rue Georges Clemenceau, 91406 Orsay Cedex (France); Fois, G. R. [Dipartimento di Fisica, Universita degli Studi di Cagliari, Strada provinciale Monserrato Sestu km 0.700, Monserrato, Cagliari 09042 (Italy)

2013-03-15

300

Dynamic optical modulation of the electron beam for the high performance intensity modulated radiation therapy  

Microsoft Academic Search

The radiation therapy of cancer is developing to non-uniform irradiation as intensity modulated radiation therapy (IMRT), reducing the dose to normal tissue and concentrating the dose to cancer tissue. A photocathode RF gun is able to generate a low emittance electron beam pulse using laser light. We thought that a photocathode RF gun can generate an intensity-modulated electron beam by

T. Kondoh; H. Kashima; J. Yang; Y. Yoshida

2007-01-01

301

Evaluating geometrical accuracy of image registration methods in SPECT guided radiation therapy  

E-print Network

) plays an important role in the treatment of patients with lung cancer. The goal of radiation therapyEvaluating geometrical accuracy of image registration methods in SPECT guided radiation therapy John Powe 7 Daniel Worsley 7 Vitali Moiseenko 1,2 (1) Physics and Astronomy, University of British

Hamarneh, Ghassan

302

CLARET: A Fast Deformable Registration Method Applied to Lung Radiation Therapy  

E-print Network

-Guided Radiation Therapy (IGRT) emphasize the capability of fast treatment-time tumor localization while using lowCLARET: A Fast Deformable Registration Method Applied to Lung Radiation Therapy Chen-Rui Chou1 Hill, NC 4 Kitware, Inc., Clifton Park, NY 5 Dept. of Medical Physics, Memorial Sloan-Kettering Cancer

303

Hyperfractionated craniospinal radiation therapy for primitive neuroectodermal tumors: results of a phase II study  

Microsoft Academic Search

Purpose: To report the results of a Phase II study of hyperfractionated craniospinal radiation therapy, with and without adjuvant chemotherapy for primitive neuroectodermal brain tumors (PNETs) and malignant ependymomas.Methods and Materials: Newly diagnosed PNET or malignant ependymomas were treated with hyperfractionated craniospinal radiation therapy. The primary tumor site was treated to a dose of 72 Gy, with 30 Gy given

Michael D Prados; Michael S. B Edwards; Susan M Chang; Carolyn Russo; Richard Davis; Jane Rabbitt; Margaretta Page; Kathleen Lamborn; William M Wara

1999-01-01

304

Early hyperbaric oxygen therapy improves outcome for radiation-induced hemorrhagic cystitis  

Microsoft Academic Search

ObjectivesTo assess the clinical factors that affect the efficacy of hyperbaric oxygen (HBO2) therapy in treating radiation-induced hemorrhagic cystitis. HBO2 therapy is an effective treatment for radiation-induced hemorrhagic cystitis, with reported response rates ranging from 76% to 100%.

Kian Tai Chong; Neil B. Hampson; John M. Corman

2005-01-01

305

Role of stereotactic body radiation therapy for hepatocellular carcinoma.  

PubMed

The integration of new technologies has raised an interest in liver tumor radiotherapy, with literature evolving to support its efficacy. These advances, particularly stereotactic body radiation therapy (SBRT), have been critical in improving local control or potential cure in liver lesions not amenable to first-line surgical resection or radiofrequency ablation. Active investigation of SBRT, particularly for hepatocellular carcinoma (HCC), has recently started, yielding promising local control rates. In addition, data suggest a possibility that SBRT can be an alternative option for HCC unfit for other local therapies. However, information on optimal treatment indications, doses, and methods remains limited. In HCC, significant differences in patient characteristics and treatment availability exist by country. In addition, the prognosis of HCC is greatly influenced by underlying liver dysfunction and treatment itself in addition to tumor stage. Since they are closely linked to treatment approach, it is important to understand these differences in interpreting outcomes from various reports. Further studies are required to validate and maximize the efficacy of SBRT by a large, multi-institutional setting. PMID:24696597

Sanuki, Naoko; Takeda, Atsuya; Kunieda, Etsuo

2014-03-28

306

On bolus for megavoltage photon and electron radiation therapy  

SciTech Connect

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.

Vyas, Vedang [University of Waterloo, Waterloo, Ontario (Canada); Grand River Regional Cancer Centre, Kitchener, Ontario (Canada); Palmer, Lisa; Mudge, Ray [Grand River Regional Cancer Centre, Kitchener, Ontario (Canada); Jiang, Runqing [University of Waterloo, Waterloo, Ontario (Canada); Grand River Regional Cancer Centre, Kitchener, Ontario (Canada); Fleck, Andre [Grand River Regional Cancer Centre, Kitchener, Ontario (Canada); Schaly, Bryan [London Regional Cancer Program, London, Ontario (Canada); Osei, Ernest [University of Waterloo, Waterloo, Ontario (Canada); Grand River Regional Cancer Centre, Kitchener, Ontario (Canada); Charland, Paule, E-mail: paule.charland@grhosp.on.ca [Grand River Regional Cancer Centre, Kitchener, Ontario (Canada)

2013-10-01

307

Automated fiducial marker planning for thoracic stereotactic body radiation therapy  

NASA Astrophysics Data System (ADS)

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.

Gibbs, Jason D.; Rai, Lav; Wibowo, Henky; Tsalyuk, Serge; Anderson, Eric D.

2012-02-01

308

Role of stereotactic body radiation therapy for hepatocellular carcinoma  

PubMed Central

The integration of new technologies has raised an interest in liver tumor radiotherapy, with literature evolving to support its efficacy. These advances, particularly stereotactic body radiation therapy (SBRT), have been critical in improving local control or potential cure in liver lesions not amenable to first-line surgical resection or radiofrequency ablation. Active investigation of SBRT, particularly for hepatocellular carcinoma (HCC), has recently started, yielding promising local control rates. In addition, data suggest a possibility that SBRT can be an alternative option for HCC unfit for other local therapies. However, information on optimal treatment indications, doses, and methods remains limited. In HCC, significant differences in patient characteristics and treatment availability exist by country. In addition, the prognosis of HCC is greatly influenced by underlying liver dysfunction and treatment itself in addition to tumor stage. Since they are closely linked to treatment approach, it is important to understand these differences in interpreting outcomes from various reports. Further studies are required to validate and maximize the efficacy of SBRT by a large, multi-institutional setting. PMID:24696597

Sanuki, Naoko; Takeda, Atsuya; Kunieda, Etsuo

2014-01-01

309

Impact of CT CORRELATE ScoutView images on radiation therapy planning  

SciTech Connect

CORRELATE is a new computer software program for CT that enables a radiologist to mark tumor margins on traditional CT cross-sectional images and then display the outline of that same tumor on CT ScoutView images. This function is particularly useful for radiation therapy planning because CORRELATE ScoutView images are in the same longitudinal plane as simulation radiographs used for tumor localization in radiation therapy. The impact of CORRELATE on the radiation therapy planning process was measured in 83 patients with various tumors. Therapy planning was performed before and after CORRELATE information was made available to the radiation therapist. CORRELATE information caused a change in the therapy plan in 77% of the cases and increased confidence in the therapy plan in an additional 22%. CORRELATE provides a useful and accurate tool for tumor localization.

Shuman, W.P.; Griffin, B.R.; Yoshy, C.S.; Listerud, J.A.; Mack, L.A.; Rowberg, A.H.; Moss, A.A.

1985-09-01

310

Very High Energy Electrons (VHEE) have the potential to be an alternative or complementary radiation therapy  

E-print Network

Techniques designed for you Laser-plasma driven VHEE cancer therapy Using this technology, a higher number radiation therapy to x-ray and ions for cancer treatment. Background Despite numerous studies showing discouraged further investigation of using VHEE in radiotherapy. The electron energy required for VHEE therapy

Strathclyde, University of

311

Surgical treatment and radiation therapy of frontal lobe meningiomas in 7 dogs  

PubMed Central

The cases of 7 adult dogs with generalized seizures managed by surgical excision and radiation therapy for frontal lobe meningiomas were reviewed. The neurological examination was unremarkable in 6 of the 7 dogs. Five dogs were operated on using a bilateral transfrontal sinus approach and 2 using a unilateral sinotemporal approach to the frontal lobe. One dog was euthanized 14 d after surgery; radiation therapy was initiated 3 wk after surgery in the remaining 6 dogs. Long-term follow-up consisted of neurological examination and magnetic resonance imaging (MRI) and/or computed tomography (CT) scan after radiation therapy. The mean survival time for dogs that had surgery and radiation therapy was 18 mo after surgery. Frontal lobe meningiomas have been associated with poor prognosis. However, the surgical approaches used in these cases, combined with radiation therapy, allow a survival rate for frontal lobe meningiomas similar to that for meningiomas located over the cerebral convexities. PMID:22210938

Uriarte, Ane; Moissonnier, Pierre; Thibaud, Jean-Laurent; Reyes-Gomez, Edouard; Devauchelle, Patrick; Blot, Stéphane

2011-01-01

312

Radiation Therapy Failure in Prostate Cancer Patients: Risk Factors and Methods of Detection  

PubMed Central

Radiation therapy for clinically localized prostatic carcinoma remains one of the mainstays among therapeutic approaches; however, patients continue to fail radiation therapy at too high a rate. This article reviews the risk factors and methods of detection for prostate cancer recurrence. The relative merits of the three major pre-therapy prognostic indicators—TNM staging, Gleason score, and serum prostate-specific antigen (PSA) levels—are discussed. The use of staging and Gleason score, as well as digital rectal examination, transrectal ultrasound, and post-radiation prostate biopsies in detecting failure of radiation therapy is reviewed. Challenges relating to the use of serum PSA levels as an indicator of recurrence are examined. Finally, this article makes recommendations as to procedure for evaluating patients suspected of failing radiation therapy. PMID:16986008

Brawer, Michael K

2002-01-01

313

Stereotactic Body Radiation Therapy Boost in Locally Advanced Pancreatic Cancer  

SciTech Connect

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.

Seo, Young Seok [Department of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Mi-Sook, E-mail: mskim@kcch.re.k [Department of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Yoo, Sung Yul; Cho, Chul Koo; Yang, Kwang Mo; Yoo, Hyung Jun; Choi, Chul Won [Department of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Lee, Dong Han [CyberKnife Center, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Jin [Department of Internal Medicine, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Min Suk [Department of Pathology, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kang, Hye Jin [Department of Hemato-Oncology, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, YoungHan [Department of Radiology, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2009-12-01

314

Local control after fractionated stereotactic radiation therapy for brain metastases.  

PubMed

Stereotactic radiosurgery (SRS) is frequently used in the management of brain metastases, but concerns over potential toxicity limit applications for larger lesions or those in eloquent areas. Fractionated stereotactic radiation therapy (SRT) is often substituted for SRS in these cases. We retrospectively analyzed the efficacy and toxicity outcomes of patients who received SRT at our institution. Seventy patients with brain metastases treated with SRT from 2006-2012 were analyzed. The rates of local and distant intracranial progression, overall survival, acute toxicity, and radionecrosis were determined. The SRT regimen was 25 Gy in 5 fractions among 87 % of patients. The most common tumor histologies were non-small cell lung cancer (37 %), breast cancer (20 %) and melanoma (20 %), and the median tumor diameter was 1.7 cm (range 0.4-6.4 cm). Median survival after SRT was 10.7 months. Median time to local progression was 17 months, with a local control rate of 68 % at 6 months and 56 % at 1 year. Acute toxicity was seen in 11 patients (16 %), mostly grade 1 or 2 with the most common symptom being mild headache. Symptomatic radiation-induced treatment change was seen on follow-up MRIs in three patients (4.3 %). SRT appears to be a safe and reasonably effective technique to treat brain metastases deemed less suitable for SRS, though dose intensification strategies may further improve local control. PMID:25059451

Rajakesari, Selvan; Arvold, Nils D; Jimenez, Rachel B; Christianson, Laura W; Horvath, Margaret C; Claus, Elizabeth B; Golby, Alexandra J; Johnson, Mark D; Dunn, Ian F; Lee, Eudocia Q; Lin, Nancy U; Friesen, Scott; Mannarino, Edward G; Wagar, Matthew; Hacker, Fred L; Weiss, Stephanie E; Alexander, Brian M

2014-11-01

315

Radiation therapy of conjunctival and orbital lymphoid tumors  

SciTech Connect

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.

Jereb, B.; Lee, H.; Jakobiec, F.A.; Kutcher, J.

1984-07-01

316

A review on photoneutrons characteristics in radiation therapy with high-energy photon beams  

PubMed Central

In radiation therapy with high-energy photon beams (E > 10 MeV) neutrons are generated mainly in linacs head thorough (?,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

Naseri, Alireza; Mesbahi, Asghar

2010-01-01

317

An emerging role for radiation therapy in the treatment of hepatocellular carcinoma and intrahepatic cholangiocarcinoma.  

PubMed

Radiation therapy is emerging as a potentially effective treatment of locally advanced, unresectable hepatocellular carcinoma (HCC). Outcomes from early prospective studies seem promising, with improved survival compared with historical controls. Cure of early stage and unresectable HCC may be possible with high-quality radiation therapy. Many questions remain, including determination of the ideal radiation dose and fractionation schema, optimal patient selection criteria based on tumor size, tumor location, extent of vascular invasion, and baseline liver function, and the role of radiation therapy compared with other localized standard treatments including radiofrequency ablation or transarterial chemoembolization. PMID:24560114

Wo, Jennifer Y; Dawson, Laura A; Zhu, Andrew X; Hong, Theodore S

2014-04-01

318

UNC study find Intensity Modulated Radiation Therapy optimal for localized prostate cancer  

Cancer.gov

A treatment for localized prostate cancer known as Intensity Modulated Radiation Therapy (IMRT) is better than conventional conformal radiation therapy (CRT) for reducing certain side effects and preventing cancer recurrence, according to a study published in the April 18, 2012 issue of the Journal of the American Medical Association... The study also showed IMRT to be as effective as proton therapy, a newer technique that has grown in popularity in recent years.

319

Fewer weeks of hormone therapy before radiation reduces side effects in intermediate risk prostate cancer  

Cancer.gov

A shorter course of androgen suppression therapy prior to radiation therapy, when compared to a longer course of androgen suppression therapy, yields favorable outcomes and fewer adverse effects for intermediate-risk prostate cancer patients, according to research presented at the American Society for Radiation Oncology's (ASTRO) 55th Annual Meeting by researchers from the Mayo Clinic. The study confirmed a disease-specific-survival (DSS) rate of 95 percent when patients received fewer weeks of neoadjuvant (NEO) total androgen suppression (TAS).

320

Direct aperture optimization for online adaptive radiation therapy  

SciTech Connect

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.

Mestrovic, Ante; Milette, Marie-Pierre; Nichol, Alan; Clark, Brenda G.; Otto, Karl [Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada and Medical Physics, BC Cancer Agency-Vancouver Centre, Vancouver, British Columbia (Canada); Physics and Astronomy, University of British Columbia, Vancouver, British Columbia (Canada) and Medical Physics, BC Cancer Agency-Centre for the Southern Interior, Kelowna, British Columbia (Canada); Department of Radiation Oncology, BC Cancer Agency-Vancouver Centre, Vancouver, British Columbia (Canada); Medical Physics, Ottawa Hospital Regional Cancer Centre, Ottawa, Ontario (Canada); Medical Physics, BC Cancer Agency-Vancouver Centre, Vancouver, British Columbia (Canada)

2007-05-15

321

The importance of hemorrhage in the relationship between gross morphologic characteristics and cerebral symptoms in 376 carotid artery plaques.  

PubMed Central

In a prospective study 376 carotid artery plaques (275 symptomatic, 101 asymptomatic) were obtained from endarterectomies (184 unilateral and 96 bilateral) in 280 patients. The gross morphologic features of each plaque were noted at surgery and, together with the patient's clinical history, stored in computer memory. These data were analyzed in order to investigate the relationship of gross morphologic plaque characteristics with both the presence of cerebral symptoms and the degree of stenosis associated with the plaque. Ulceration was the most frequently observed of the five major gross plaque morphologic characteristics (46.0% of all plaques), but only intramural hemorrhage (30.6% of all plaques) was significantly more common in all symptomatic compared with all asymptomatic plaques (p less than 0.02). Hemorrhage was also the only gross characteristic significantly more common in focal symptomatic plaques when compared with either asymptomatic plaques (p less than 0.05) or nonfocal symptomatic plaques (p less than 0.01). When all the plaques were divided into three broad degrees of stenosis groups (0-39%, 40-69%, 70-99%) on the basis of angiographic data, only hemorrhage showed a significant correlation in incidence with increased degree of plaque stenosis, both when all plaques were considered (p less than 0.001) and when only symptomatic plaques were examined (p less than 0.001). The results indicate that intramural hemorrhage is the only carotid plaque gross morphologic characteristic significantly more frequent in symptomatic compared with asymptomatic plaques and the only characteristic significantly correlated with increased plaque size. These findings indicate that factors other than plaque ulceration and intraluminal thrombus play an important role in carotid plaque related cerebral symptoms. The data also raise questions concerning the unequivocal value of anticoagulant therapy in carotid artery disease, especially in highly stenotic lesions. Images Fig. 1. Fig. 1. PMID:6824372

Imparato, A M; Riles, T S; Mintzer, R; Baumann, F G

1983-01-01

322

A Case of Bladder Cancer after Radiation Therapy for Prostate Cancer  

PubMed Central

An 86-year-old male who presented with the chief complaint of clot retention and had a history of prostate cancer treated with external beam radiation therapy 11 years previously is described. Cystoscopy revealed radiation cystitis in coexistence with bladder cancer. Since bladder cancer may be present in patients with macroscopic hematuria who have a history of radiation therapy, referral to an urologist is recommended. PMID:24803918

Kaburaki, Naoto; Kosaka, Takeo; Yazawa, Satoshi; Oya, Mototsugu

2014-01-01

323

Clinical experience with intensity modulated radiation therapy (IMRT) in prostate cancer  

Microsoft Academic Search

Purpose: To compare acute and late toxicities of high-dose radiation for prostate cancer delivered by either conventional three-dimensional conformal radiation therapy (3D-CRT) or intensity modulated radiation therapy (IMRT).Materials and methods: Between September 1992 and February 1998, 61 patients with clinical stage T1c- T3 prostate cancer were treated with 3D-CRT and 171 with IMRT to a prescribed dose of 81 Gy.

Michael J Zelefsky; Zvi Fuks; Laura Happersett; Henry J Lee; C. Clifton Ling; Chandra M Burman; Margie Hunt; Theresa Wolfe; E. S Venkatraman; Andrew Jackson; Mark Skwarchuk; Steven A Leibel

2000-01-01

324

Acute myelogenous leukemia following radiation therapy and chemotherapy for osteogenic sarcoma  

SciTech Connect

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.

Jacobs, A.D.; Gale, R.P.

1984-06-01

325

Neutron, Proton, and Photonuclear Cross Sections for Radiation Therapy and Radiation Protection  

SciTech Connect

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.

Chadwick, M.B.

1998-09-10

326

Identification of amyloid plaques in retinas from Alzheimer's patients and noninvasive in vivo optical imaging of retinal plaques in a mouse model.  

PubMed

Noninvasive monitoring of ?-amyloid (A?) plaques, the neuropathological hallmarks of Alzheimer's disease (AD), is critical for AD diagnosis and prognosis. Current visualization of A? plaques in brains of live patients and animal models is limited in specificity and resolution. The retina as an extension of the brain presents an appealing target for a live, noninvasive optical imaging of AD if disease pathology is manifested there. We identified retinal A? 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 APP(SWE)/PS1(?E9) transgenic mice (AD-Tg; n=18) but not in non-Tg wt mice (n=10), retinal A? 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 A? 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 A? plaques in vivo with high resolution and specificity; plaques were undetectable in non-Tg wt mice (n=11). Our discovery of A? 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

Koronyo-Hamaoui, Maya; Koronyo, Yosef; Ljubimov, Alexander V; Miller, Carol A; Ko, Minhee K; Black, Keith L; Schwartz, Michal; Farkas, Daniel L

2011-01-01

327

Stereotactic Body Radiation Therapy in Recurrent Hepatocellular Carcinoma  

SciTech Connect

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.

Huang, Wen-Yen [Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (China)] [Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (China); Jen, Yee-Min, E-mail: yeeminjen@yahoo.com.tw [Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (China)] [Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (China); Lee, Meei-Shyuan [School of Public Health, National Defense Medical Center, Taipei, Taiwan (China)] [School of Public Health, National Defense Medical Center, Taipei, Taiwan (China); Chang, Li-Ping [Department of Radiation Oncology, Cardinal Tien Hospital, Taipei, Taiwan (China)] [Department of Radiation Oncology, Cardinal Tien Hospital, Taipei, Taiwan (China); Chen, Chang-Ming [Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (China)] [Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (China); Ko, Kai-Hsiung [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (China)] [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (China); Lin, Kuen-Tze; Lin, Jang-Chun; Chao, Hsing-Lung; Lin, Chun-Shu; Su, Yu-Fu; Fan, Chao-Yueh; Chang, Yao-Wen [Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (China)] [Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (China)

2012-10-01

328

Hypofractionated Radiation Therapy for Breast Ductal Carcinoma In Situ  

SciTech Connect

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.

Hathout, Lara [Department of Radiation Oncology, Hôpital Maisonneuve-Rosemont, Centre affilié à l'Université de Montréal, Montreal, Quebec (Canada); Hijal, Tarek [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Théberge, Valérie [Department of Radiation Oncology, Centre hospitalier universitaire de Québec, L'Hôtel-Dieu de Québec, Quebec (Canada); Centre des maladies du sein Deschênes-Fabia, Quebec (Canada); Fortin, Bernard [Department of Radiation Oncology, Hôpital Maisonneuve-Rosemont, Centre affilié à l'Université de Montréal, Montreal, Quebec (Canada); Vulpe, Horia [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Hogue, Jean-Charles [Centre des maladies du sein Deschênes-Fabia, Quebec (Canada); Centre hospitalier universitaire de Québec, Hôpital St-Sacrement, Quebec (Canada); Lambert, Christine [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Bahig, Houda [Department of Radiation Oncology, Hôpital Maisonneuve-Rosemont, Centre affilié à l'Université de Montréal, Montreal, Quebec (Canada); and others

2013-12-01

329

Research on a correlation between Cox2 protein expression and the resistance of radiation therapy in esophageal squamous cell carcinoma  

Microsoft Academic Search

Objective To study a correlation between the resistance of radiation therapy in esophageal squamous cell carcinoma and Cox-2 protein expression for cancer organization before radiation therapy. Methods 76 cases were treated by pathology and confirmed the diagnosis of patients with esophageal squamous cell carcinoma, and all by radical radiation therapy for 6MV X-ray, illuminated the dose of 60 Gy. According

Hui Wu; Qing-xia Fan

2011-01-01

330

Analysis of preoperative combined bleomycin and radiation therapy for esophageal carcinoma  

Microsoft Academic Search

Evaluation of the preoperative combined bleomycin (BLM) and radiation therapy for esophageal carcinoma was undertaken. Of 206 patients with esophageal carcinomas resected and histologically examined, 109 were treated with BLM and radiation (BR group) and compared with the other groups consisting of group R which was treated with radiation alone, group B with BLM alone, and group N with no

Jun Soga; Masao Fujimaki; Otsuo Tanaka; Koichi Sasaki; Masaki Kawaguchi; Terukazu Muto

1983-01-01

331

Radiation therapy after breast augmentation or reconstruction in early or recurrent breast cancer  

Microsoft Academic Search

Fourteen patients whose augmented or reconstructed breasts were treated with radiation therapy were analyzed. Silicone gel implants were used in 13 patients and free-injected silicone in one patient. The total radiation dose ranged from 4400 to 6200 cGy using tangential photon fields or an en face electron field by megavoltage equipment. In several cases, electron boost radiation was added to

Janice Ryu; Joachim Yahalom; Brenda Shank; Ted A. Chaglassian; Beryl McCormick

1990-01-01

332

A practical three-dimensional dosimetry system for radiation therapy  

SciTech Connect

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.

Guo Pengyi; Adamovics, John; Oldham, Mark [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Department of Chemistry and Biology, Rider University, Lawrenceville, New Jersey 08648 (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

2006-10-15

333

Radiation therapy for children: evolving technologies in the era of ALARA.  

PubMed

The evolution of ever more sophisticated oncologic imaging and technologies providing far more precise radiation therapy have combined to increase the utilization of sophisticated radiation therapy in childhood cancer. For a majority of children with common central nervous system, soft tissue, bone, and dysontogenic neoplasms, local irradiation is fundamental to successful multi-disciplinary management. Along with more precise target volume definition and radiation delivery, new technologies provide added certainty of patient positioning (electronic portal imaging, cone beam CT) and conformality of dose delivery (3-D conformal irradiation, intensity modulated radiation therapy, proton beam therapy). Each of the major areas of technology development are able to better confine the high-dose region to the intended target, but they are also associated with the potential for larger volumes of uninvolved tissues being exposed to low radiation doses. The latter issue plays a role in documented levels of secondary carcinogenesis, sometimes with greater anticipated incidence than that seen in conventional radiation therapy. Parameters related to carcinogenesis, such as dose-volume relationships and neutron contamination that accompanies high-energy photon irradiation and proton therapy, can be identified, sometimes modulated, and accepted as part of the clinical decision process in fine tuning radiation therapy in this more vulnerable age group. PMID:19083214

Kun, Larry E; Beltran, Chris

2009-02-01

334

Organizing pneumonia after radiation therapy for breast cancer.  

PubMed

We report a case of organizing pneumonia (OP) that developed after radiation therapy (RT) for breast cancer. A 54-year-old woman presented with malaise and fever within a month after the completion of RT for breast cancer. Chest radiographs and computed tomography (CT) demonstrated consolidation in the left upper lobe consistent with radiation pneumonia. The patient was given 60 mg/day IV cortisone for 15 days after which her complaints and consolidation in the left upper lobe disappeared. The daily dose of her corticosteroid was tapered down to 20 mg/day. Two weeks later, the patient again had fever and malaise. Chest X-ray and CT revealed bilateral pulmonary opacities located outside the irradiated fields, predominantly in the middle and lower lung zones. The patient's laboratory tests were normal except for her erythrocyte sedimentation rate, which was elevated. Bronchial lavage revealed moderate elevation of the total cell number with lymphocyte predominance. Open lung biopsy was performed and histopathological examination demonstrated findings consistent with OP. High dose (60 mg/day) prednisolone treatment resulted in rapid clinical and radiological improvement. When the prednisolone dose was gradually tapered down to 20 mg/day during follow-up, new pulmonary opacities developed in both lungs, as well as the recurrence of the patient's symptoms. Increased dose of prednisolone resulted in the rapid improvement of the clinical symptoms and radiological abnormalities. OP rarely presents after RT for breast and lung cancer. One should always consider OP in the clinical setting of a patient who has a history of RT completed 3-6 months prior to fever, multiple areas of consolidation, and ground glass opacities outside the RT field. PMID:16972215

Erdo?an, Erhan; Demirkazik, Figen Ba?aran; Emri, Salih; Firat, Pinar

2006-09-01

335

Biochemical Response to Androgen Deprivation Therapy Before External Beam Radiation Therapy Predicts Long-term Prostate Cancer Survival Outcomes  

SciTech Connect

Purpose: To determine whether the response to neoadjuvant androgen deprivation therapy (ADT) defined by a decline in prostate-specific antigen (PSA) to nadir values is associated with improved survival outcomes after external beam radiation therapy (EBRT) for prostate cancer. Methods and Materials: One thousand forty-five patients with localized prostate cancer were treated with definitive EBRT in conjunction with neoadjuvant and concurrent ADT. A 6-month course of ADT was used (3 months during the neoadjuvant phase and 2 to 3 months concurrently with EBRT). The median EBRT prescription dose was 81 Gy using a conformal-based technique. The median follow-up time was 8.5 years. Results: The 10-year PSA relapse-free survival outcome among patients with pre-radiation therapy PSA nadirs of ?0.3 ng/mL was 74.3%, compared with 57.7% for patients with higher PSA nadir values (P<.001). The 10-year distant metastases-free survival outcome among patients with pre-radiation therapy PSA nadirs of ?0.3 ng/mL was 86.1%, compared with 78.6% for patients with higher PSA nadir values (P=.004). In a competing-risk analysis, prostate cancer-related deaths were also significantly reduced among patients with pre-radiation therapy PSA nadirs of <0.3 ng/mL compared with higher values (7.8% compared with 13.7%; P=.009). Multivariable analysis demonstrated that the pre-EBRT PSA nadir value was a significant predictor of long-term biochemical tumor control, distant metastases-free survival, and cause-specific survival outcomes. Conclusions: Pre-radiation therapy nadir PSA values of ?0.3 ng/mL after neoadjuvant ADT were associated with improved long-term biochemical tumor control, reduction in distant metastases, and prostate cancer-related death. Patients with higher nadir values may require alternative adjuvant therapies to improve outcomes.

Zelefsky, Michael J., E-mail: zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Gomez, Daniel R.; Polkinghorn, William R.; Pei, Xin; Kollmeier, Marisa [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

2013-07-01

336

Does Hormone Therapy Reduce Disease Recurrence in Prostate Cancer Patients Receiving Dose-Escalated Radiation Therapy? An Analysis of Radiation Therapy Oncology Group 94-06  

SciTech Connect

Purpose: The purpose of this study was to evaluate the effect on freedom from biochemical failure (bNED) or disease-free survival (DFS) by adding hormone therapy (HT) to dose-escalated radiation therapy (HDRT). Methods and Materials: We used 883 analyzable prostate cancer patients who enrolled on Radiation Therapy Oncology Group (RTOG) 94-06, a Phase I/II dose escalation trial, and whose mean planning target volume dose exceeded 73.8 Gy (mean, 78.5 Gy; maximum, 84.3 Gy). We defined biochemical failure according to the Phoenix definition. Results: A total of 259 men started HT 2 to 3 months before HDRT, but not longer than 6 months, and 66 men with high-risk prostate cancer received HT for a longer duration. At 5 years, the biochemical failure rates after HDRT alone were 12%, 18%, and 29% for low-, intermediate-, and high-risk patients, respectively (p < 0.0001). Cox proportional hazards regression analysis adjusted for covariates revealed that pretreatment PSA level was a significant factor, whereas risk group, Gleason score, T-stage, and age were not. When the patients were stratified by risk groups, the Cox proportion hazards regression model (after adjusting for pretreatment PSA, biopsy Gleason score, and T stage) did not reveal a significant effect on bNED or DFS by adding HT to HDRT Conclusion: The addition of HT did not significantly improve bNED survival or DFS in all prostate cancer patients receiving HDRT, but did approach significance in high-risk patient subgroup. The result of this study is hypothesis generating and requires testing in a prospective randomized trial.

Valicenti, Richard K., E-mail: richard.valicenti@ucdmc.ucdavis.ed [Department of Radiation Oncology, University of California-Davis School of Medicine, Davis, CA (United States); Bae, Kwounghwa [Department of Statistics, Radiation Therapy Oncology Group, Philadelphia, PA (United States); Michalski, Jeff [Department of Radiation Oncology, Washington University, St. Louis, MO (United States); Sandler, Howard [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Shipley, William [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Lin, Alex [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Cox, James [Division of Radiation Oncology, MD Anderson Cancer Center, Houston, TX (United States)

2011-04-01

337

Intensity-Modulated Radiation Therapy in Childhood Ependymoma  

SciTech Connect

Purpose: To determine the patterns of failure after intensity-modulated radiation therapy (IMRT) for localized intracranial ependymoma. Methods and Materials: From 1994 to 2005, 22 children with pathologically proven, localized, intracranial ependymoma were treated with adjuvant IMRT. Of the patients, 12 (55%) had an infratentorial tumor and 14 (64%) had anaplastic histology. Five patients had a subtotal resection (STR), as evidenced by postoperative magnetic resonance imaging. The clinical target volume encompassed the tumor bed and any residual disease plus margin (median dose 54 Gy). Median follow-up for surviving patients was 39.8 months. Results: The 3-year overall survival rate was 87% {+-} 9%. The 3-year local control rate was 68% {+-} 12%. There were six local recurrences, all in the high-dose region of the treatment field. Median time to recurrence was 21.7 months. Of the 5 STR patients, 4 experienced recurrence and 3 died. Patients with a gross total resection had significantly better local control (p = 0.024) and overall survival (p = 0.008) than those with an STR. At last follow-up, no patient had developed visual loss, brain necrosis, myelitis, or a second malignancy. Conclusions: Treatment with IMRT provides local control and survival rates comparable with those in historic publications using larger treatment volumes. All failures were within the high-dose region, suggesting that IMRT does not diminish local control. The degree of surgical resection was shown to be significant for local control and survival.

Schroeder, Thomas M. [Department of Radiation Oncology, University of New Mexico Cancer Center, University of New Mexico, Albuquerque, NM (United States); Chintagumpala, Murali; Okcu, M. Fatih [Division of Pediatric Hematology-Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX (United States); Division of Pediatric Hematology-Oncology, Department of Pediatrics, Texas Children's Hospital, Houston, TX (United States); Chiu, J. Kam; Teh, Bin S. [Department of Radiation Oncology, Methodist Hospital, Houston, TX (United States); Division of Radiation Oncology, Department of Radiology, Baylor College of Medicine, Houston, TX (United States); Woo, Shiao Y. [Department of Radiation Oncology, M.D. Anderson Cancer Center, Houston, TX (United States); Paulino, Arnold C. [Department of Radiation Oncology, Methodist Hospital, Houston, TX (United States); Division of Radiation Oncology, Department of Radiology, Baylor College of Medicine, Houston, TX (United States)], E-mail: apaulino@tmhs.org

2008-07-15

338

Acid ceramidase in prostate cancer radiation therapy resistance and relapse  

NASA Astrophysics Data System (ADS)

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.

Cheng, Joseph C.

339

Fractionated proton radiation therapy of cranial and intracranial tumors.  

PubMed

Since 1973 fractionated proton radiation therapy has been used in the treatment of malignant disease. Protons have favorable physical characteristics that yield dose distributions superior to those of photons in certain clinical situations. As of December 31, 1987, 1,678 patients had been treated. Of these, 110 had chordomas or low-grade chondrosarcomas of the base of skull. The first 68 patients have a minimum follow-up of 17 months. The median dose was 69 Cobalt Gray Equivalent (CGE). (CGE is the dose in proton Gray multiplied by 1.1, which is the relative biological effectiveness for protons relative to 60Cobalt.) The actuarial 5-year local control rate is 82%, and the disease-free survival rate is 76%. Thirteen patients with meningiomas have been treated, following subtotal resection. The median dose was 59.4 CGE. With a median follow-up of 26 months, no patient has had tumor progression. In addition, nine patients with gliomas and 12 with craniopharyngiomas have been treated. PMID:2165739

Austin-Seymour, M; Munzenrider, J; Linggood, R; Goitein, M; Verhey, L; Urie, M; Gentry, R; Birnbaum, S; Ruotolo, D; Crowell, C

1990-08-01

340

[Stereotactic body radiation therapy in the management of liver tumours].  

PubMed

Stereotactic radiotherapy is a high-precision technique based on the administration of high doses to a limited target volume. This treatment constitutes a therapeutic progress in the management of many tumours, especially hepatic ones. If surgery remains the standard local therapy, stereotactic radiotherapy is first dedicated to inoperable patients or unresectable tumours. Patients with moderately altered general status, preserved liver function and tumour lesions limited in number as in size are eligible to this technique. Results in terms of local control are satisfying, regarding primary tumours (notably hepatocellular carcinomas) as metastases stemming from various origins. If treatment protocols and follow-up modalities are not standardized to this day, iconographic acquisition using four-dimensional computed tomography, target volumes delineation based on morphological and/or metabolic data, and image-guided radiotherapy contribute to an oncologic efficacy and an improved sparing of the functional liver. The purpose of this literature review is to report the results of the main works having assessed stereotactic radiotherapy in the management of primary and secondary liver tumours. Technical particularities of this radiation modality will also be described. PMID:25195113

Jacob, J; Nguyen, F; Deutsch, E; Mornex, F

2014-10-01

341

Deformation field validation and inversion applied to adaptive radiation therapy  

NASA Astrophysics Data System (ADS)

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.

Vercauteren, Tom; De Gersem, Werner; Olteanu, Luiza A. M.; Madani, Indira; Duprez, Fréderic; Berwouts, Dieter; Speleers, Bruno; De Neve, Wilfried

2013-08-01

342

An antiproton simulation study using MCNPX for radiation therapy.  

PubMed

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

Michael Handley, Stephen; Ahmad, Salahuddin

2011-01-01

343

Registration-based initialization during radiation therapy planning  

NASA Astrophysics Data System (ADS)

An established challenge in the field of image analysis has been the registration of images having a large initial misalignment. For example in chemo and Radiation Therapy Planning (RTP), there is often a need to register an image delineating a specific anatomy (usually in the surgery position) with that of a whole body image (obtained preoperatively). In such a scenario, there is room for a large misalignment between the two images that are required to be aligned. Large misalignments are traditionally handled in two ways: 1) Semi-automatically with a user initialization or 2) With the help of the origin fields in the image header. The first approach is user dependant and the second method can be used only if the two images are obtained from the same scanner with consistent origins. Our methodology extends a typical registration framework by selecting components that are capable of searching a large parameter space without settling on local optima. We have used an optimizer that is based on an Evolutionary Scheme along with an information theory based similarity metric that can address these needs. The attempt in this study is to convert a large misalignment problem to a small misalignment problem that can then be handled using application specific registration algorithms. Further improvements along local areas can be obtained by subjecting the image to a non-rigid transformation. We have successfully registered the following pairs of images without any user initialization: CTAC - simCT (neuro, lungs); MRPET/ CT (neuro, liver); T2-SPGR (neuro).

Gopalakrishnan, Girish; Mullick, Rakesh

2007-03-01

344

Radiant{trademark} Liquid Radioisotope Intravascular Radiation Therapy System  

SciTech Connect

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.

Eigler, N.; Whiting, J.; Chernomorsky, A.; Jackson, J.; Knapp, F.F., Jr.; Litvack, F.

1998-01-16

345

A Prospective Study of Conformal Radiation Therapy for Pediatric Ependymoma  

PubMed Central

Background Successful therapy for ependymoma includes aggressive surgical intervention and radiation therapy administered using methods which minimize the risk of side effects. We extended this treatment approach to include children under the age of 3 years. Methods Between July 1997 and 2007, 153 pediatric patients (median age 2·9 years, range 0·9–22·9 years) with localized ependymoma received conformal radiation therapy after definitive surgery. Doses of 59·4 (n=131) or 54·0 Gy (n=22) were prescribed to a 10mm clinical target volume margin surrounding the post-operative residual tumor and/or tumor bed. The patients had the following characteristics: anaplastic ependymoma (n=85), infratentorial location (n=122), prior chemotherapy (n=35) and extent of resection (gross-total=125, near-total=17, subtotal=11). Disease control, patterns of failure and complications were recorded for patients followed through 10 years. Findings With a median follow-up of 5·3 years (range 0·4 to 10·4 years), death was recorded in 23 patients and tumor progression in 36, including local (n=14), distant (n=15) and combined failure (n=7). Tumor grade predicted overall (OS) and event-free (EFS) survival and distant failure. Extent of resection predicted OS, EFS and local failure. Race predicted OS. The 7 year local control, event-free and overall survival were 83·7% (95% CI: 73·9–93·5%), 69·1% (95% CI: 56·9–81·3%) and 81·0% (95% CI: 71·0–91·0%), respectively. The cumulative incidence of local and distance failure were 16·3% (95% CI: 9·6–23·0%) and 11·48% (95% CI: 5·9–17·1%), respectively. Considering only those patients treated with immediate post-operative CRT (without delay or chemotherapy) the 7 year OS, EFS and CI of local and distant failure were 85·0% (95% CI: 74·2–95·8%), 76·9% (95% CI: 63·4–90·4%), 12·59% (95% CI: 5·1–20·1%)and 8·56% (95% CI: 2·8–14·3%), respectively. The incidence of secondary malignant brain tumor at 7 years was 2·3% (95% CI: 0–5·6%) and brainstem necrosis 1·6% (95% CI: 0–4·0%). Interpretation This study provides new disease control benchmarks and a unifying approach for the treatment of ependymoma that should include surgery with the aim of gross-total resection and conformal, high-dose, post-operative irradiation even for the youngest children. Future trials might consider treatment stratification based on gender and age as female patients are more likely to be long-term survivors and younger patients have higher rates of failure. PMID:19274783

Merchant, Thomas E.; Li, Chenghong; Xiong, Xiaoping; Kun, Larry E.; Boop, Frederic A.; Sanford, Robert A.

2013-01-01

346

Optimization and quality assurance of an image-guided radiation therapy system for intensity-modulated radiation therapy radiotherapy  

SciTech Connect

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.

Tsai, Jen-San, E-mail: jen-san.tsai@verizon.net [Department of Radiation Oncology, Temple University Hospital, Philadelphia, PA (United States); Micaily, Bizhan; Miyamoto, Curtis [Department of Radiation Oncology, Temple University Hospital, Philadelphia, PA (United States)

2012-10-01

347

Outcomes of pediatric low-grade gliomas treated with radiation therapy: a single-institution study.  

PubMed

Radiation therapy is often considered the treatment of choice for low-grade gliomas. However, given the long-term effects of radiation on the developing brain, the appropriate use of radiation therapy in pediatric patients remains controversial. The purpose of this study was to evaluate progression-free survival (PFS) of pediatric low-grade glioma patients treated with radiation therapy. Data were obtained through a retrospective chart review of patients treated between 1991 and 2008 from a single tertiary care center in the midwest. The study population consisted of 17 patients, of whom 8 (47%) had tumor recurrence after radiation therapy. The median follow-up time was 8.2 years, with a range of 2.3 to 17.2 years. The median age at diagnosis was 5.4 years, and the median age at radiation therapy was 9.4 years. The 3- and the 10-year PFS were 69%± 11.7% and 46%± 13.3%, respectively. A significant difference in PFS was seen when comparing brainstem tumors with hypothalamic/optic pathway tumors (P=0.019). Differences in PFS based on the age at diagnosis, the extent of initial surgery, and indication for radiation therapy were not significant. A larger multicenter study is needed to better assess PFS in these patients. PMID:24714505

Raikar, Sunil S; Halloran, Donna R; Elliot, Michael; McHugh, Michele; Patel, Shaun; Gauvain, Karen M

2014-08-01

348

Phase II Radiation Therapy Oncology Group trial of conventional radiation therapy followed by treatment with recombinant interferon-{beta} for supratentorial glioblastoma: Results of RTOG 9710  

SciTech Connect

Purpose: The aim of this study was to determine whether recombinant human interferon {beta}-1a (rhIFN-{beta}), when given after radiation therapy, improves survival in glioblastoma. Methods and Materials: After surgery, 109 patients with newly diagnosed supratentorial glioblastoma were enrolled and treated with radiation therapy (60 Gy). A total of 55 patients remained stable after radiation and were treated with rhIFN-{beta} (6 MU/day i.m., 3 times/week). Outcomes were compared with Radiation Therapy Oncology Group glioma historical database. Results: RhIFN-{beta} was well tolerated, with 1 Grade 4 toxicity and 8 other patients experiencing Grade 3 toxicity. Median survival time (MST) of the 55 rhIFN-{beta}-treated patients was 13.4 months. MST for the 34 rhIFN-{beta}-treated in RPA Classes III and IV was 16.9 vs. 12.4 months for historical controls (hazard ratio [HR] = 1.27, 95% confidence interval [CI] = 0.89-1.81). There was also a trend toward improved survival across all RPA Classes comparing the 55 rhIFN-{beta} treated patients and 1,658 historical controls (HR = 1.24, 95% CI = 0.94-1.63). The high rate of early failures (54/109) after radiation and before initiation of rhIFN-{beta} was likely caused by stricter interpretation of early radiographic changes in the current study. Matched-pair and intent-to-treat analyses performed to try to address this bias showed no difference in survival between study patients and controls. Conclusion: RhIFN-{beta} given after conventional radiation therapy was well tolerated, with a trend toward survival benefit in patients who remained stable after radiation therapy. These data suggest that rhIFN-{beta} warrants further evaluation in additional studies, possibly in combination with current temozolomide-based regimens.

Colman, Howard [Department of Neuro-Oncology, University of Texas-M.D. Anderson Cancer Center, Houston, TX (United States) and Department of Brain Tumor Center, University of Texas-M.D. Anderson Cancer Center, Houston, TX (United States)]. E-mail: hcolman@mdanderson.org; Berkey, Brian A. [Statistics Department, Radiation Therapy Oncology Group Headquarters, Philadelphia, PA (United States); Maor, Moshe H. [Department of Radiation Oncology, University of Texas-M.D. Anderson Cancer Center, Houston, TX (United States); Department of Brain Tumor Center, University of Texas-M.D. Anderson Cancer Center, Houston, TX (United States); Groves, Morris D. [Department of Neuro-Oncology, University of Texas-M.D. Anderson Cancer Center, Houston, TX (United States); Department of Brain Tumor Center, University of Texas-M.D. Anderson Cancer Center, Houston, TX (United States); Schultz, Christopher J. [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Vermeulen, Sandra [Swedish Cancer Institute-Department of Radiation Oncology/Northwest Hospital Gamma Knife Center, Seattle, WA (United States); Nelson, Diana F. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Mehta, Minesh P. [Department of Human Oncology, University of Wisconsin Medical School, Madison, WI (United States); Yung, W.K. Alfred [Department of Neuro-Oncology, University of Texas-M.D. Anderson Cancer Center, Houston, TX (United States); Department of Brain Tumor Center, University of Texas-M.D. Anderson Cancer Center, Houston, TX (United States)

2006-11-01

349

RADIOACTIVE RADIATION INJURY: ITS ORIGIN, SYMPTOMATOLOGY, PROPHYLAXIS, AND THERAPY  

Microsoft Academic Search

Drugs and techniques employed in the prevention and treatment of ; radiation injury are described, and there is a discussion on: the nature of ; ionizing radiations, both of the primary and secondary type; primary and ; secondary reactions of radiations with biological materials and systems; the ; interaction of radiations with sulfhydryl groups; the means by which human ;

Dolder

1963-01-01

350

Gold nanoparticles enhance the radiation therapy of a murine squamous cell carcinoma  

NASA Astrophysics Data System (ADS)

The purpose of this study is to test the hypothesis that gold nanoparticle (AuNP, nanogold)-enhanced radiation therapy (nanogold radiation therapy, NRT) is efficacious when treating the radiation resistant and highly aggressive mouse head and neck squamous cell carcinoma model, SCCVII, and to identify parameters influencing the efficacy of NRT. Subcutaneous (sc) SCCVII leg tumors in mice were irradiated with x-rays at the Brookhaven National Laboratory (BNL) National Synchrotron Light Source (NSLS) with and without prior intravenous (iv) administration of AuNPs. Variables studied included radiation dose, beam energy, temporal fractionation and hyperthermia. AuNP-mediated NRT was shown to be effective for the sc SCCVII model. AuNPs were more effective at 42 Gy than at 30 Gy (both at 68 keV median beam energy) compared to controls without gold. Similarly, at 157 keV median beam energy, 50.6 Gy NRT was more effective than 44 Gy NRT. At the same radiation dose (~42 Gy), 68 keV was more effective than 157 keV. Hyperthermia and radiation therapy (RT) were synergistic and AuNPs enhanced this synergy, thereby further reducing TCD50 s (tumor control dose 50%) and increasing long-term survivals. It is concluded that gold nanoparticles enhance the radiation therapy of a radioresistant mouse squamous cell carcinoma. The data show that radiation dose, energy and hyperthermia influence efficacy and better define the potential utility of gold nanoparticles for cancer x-ray therapy.

Hainfeld, James F.; Avraham Dilmanian, F.; Zhong, Zhong; Slatkin, Daniel N.; Kalef-Ezra, John A.; Smilowitz, Henry M.

2010-06-01

351

The tolerance of skin grafts to postoperative radiation therapy in patients with soft-tissue sarcoma  

SciTech Connect

During the last ten years at the National Cancer Institute, 11 patients have received 12 courses of postoperative adjuvant radiation therapy to skin grafts used for wound closure after the resection of soft-tissue sarcomas. The intervals between grafting and the initiation of radiation ranged between 3 and 20 weeks, and 4 patients received chemotherapy at the same time as their radiation. Ten of the 12 irradiated grafts remained intact after the completion of therapy. One graft had several small persistently ulcerated areas that required no further surgical treatment, and one graft required a musculocutaneous flap for reconstruction of a persistent large ulcer. Acute radiation effects on the grafted skin sometimes developed at slightly lower doses than usually seen with normal skin, but these acute effects necessitated a break in therapy on only five occasions. Concurrent chemotherapy and a relatively short interval between grafting and the initiation of radiation seemed to contribute to more severe radiation reactions. This experience indicates that postoperative adjuvant radiation therapy can be delivered to skin grafted areas without undue fear of complications, especially if the graft is allowed to heal adequately prior to initiating therapy and if chemotherapy is not given in conjunction with radiation.

Lawrence, W.T.; Zabell, A.; McDonald, H.D. (National Cancer Institute, Bethesda, MD (USA))

1986-03-01

352

Report from the Radiation Therapy Committee of the Southwest Oncology Group (SWOG): Research Objectives Workshop 2008  

PubMed Central

Strategic planning for the Radiation Therapy Committee of the Southwest Oncology Group (SWOG) is comprehensively evaluated every six years in an effort to maintain a current and relevant scientific focus, and to provide a standard platform for future development of protocol concepts. Participants in the 2008 Strategic Planning Workshop included clinical trial experts from multiple specialties, industry representatives from both pharmaceuticals and equipment manufacturers, and basic scientists. High priority research areas such as image-guided radiation therapy for control of limited metastatic disease, analysis of biomarkers for treatment response and late toxicity, assessment of novel agents in combination with radiation, standardization of radiation target delineation, and the assessment of new imaging techniques to individualize cancer therapy, were discussed. Research priorities included clinical study designs featuring translational endpoints that identify patients most likely to benefit from combined modality therapy; intervention including combination radiation with standard chemotherapy; radiation with radiosensitizing molecular-targeted therapies; and stereotactic radiation for treatment of patients with regard to asymptomatic metastasis and radiation-induced tumor autoimmunity. The Committee concluded that the future research opportunities are among the most exciting to have developed in the last decade, and work is in progress to embark on these plans. PMID:19723641

Okunieff, Paul; Kachnic, Lisa A; Constine, Louis S; Fuller, Clifton D; Gaspar, Laurie E; Hayes, Daniel F; Hooks, Jean; Ling, Clifton; Meyskens, Frank L; Philip, Philip A; Raben, David; Smalley, Stephen R; Swanson, Gregory P; Teicher, Beverly A; Thomas, Charles R; Vikram, Bhadrasain; Zelefsky, Michael J; Baker, Laurence H

2010-01-01

353

Clinical proton radiation therapy research at the Francis H. Burr Proton Therapy Center.  

PubMed

The Francis H. Burr Proton Therapy Center has a 230 MeV cyclotron from which proton beams are directed to two isocentric gantries, a stereotactic intracranial beam line, and an eye line. Because of improved physical dose distribution, proton radiotherapy allows dose escalation to improve local tumor control in anatomic sites and histologies where local control is suboptimal with photons. The improved dose localization also reduces normal-tissue doses with an anticipated reduction in acute and late toxicity. Clinical treatment protocols, developed to exploit the dosimetric advantages of protons over photons, have been grouped into two broad categories. In the first, dose is escalated for anatomic sites where local control with conventional radiation doses has been suboptimal. In the second, normal-tissue sparing with protons is designed to minimize acute and late toxicity. Treatment of patients on clinical research protocols has been encouraged. Patient treatments began on the first gantry in November 2001; on the eye line in April 2002; on the second gantry in May 2002; and on the stereotactic intracranial line in August 2006. The facility currently treats 60 patients per day, including up to six children daily under anesthesia. Dose-escalation studies have been completed for early stage prostate cancer (in conjunction with Loma Linda University) and sarcomas of the cervical spine/base of skull and thoracolumbosacral spine. Protocols are in progress or development for carcinoma of the nasopharynx, paranasal sinus carcinoma, non-small-cell lung carcinoma, locally advanced carcinoma of the prostate, hepatocellular carcinoma, and pancreatic cancer. Studies evaluating the use of protons for morbidity reduction include protocols for craniospinal irradiation in conjunction with systemic chemotherapy for medulloblastoma, retinoblastoma, pediatric rhabdomyosarcoma, other pediatric sarcomas, and accelerated, hypofractionated partial breast irradiation for T1N0 breast carcinomas. For pediatric patients, protons have also been accepted as an alternative to photons for children enrolled in Children's Oncology Group (COG) protocols. Treatment of patients on these studies has often required the development of new treatment techniques (i.e., matching abutting fields for craniospinal irradiation), respiratory gating, and development of appropriate clinical infrastructure support (i.e., increase in availability of pediatric anesthesia) to allow appropriate treatment. In addition, a clinical research infrastructure for protocol development and data management is required. Results to date indicate that proton radiation therapy offers several potential treatment advantages to patients that can be studied in the setting of clinical trials. Patients' willingness to enter these clinical trials seems to be quite high; accrual to selected studies has been favorable. PMID:17668954

DeLaney, Thomas F

2007-08-01

354

Comparative analysis of 60Co intensity-modulated radiation therapy.  

PubMed

In this study, we perform a scientific comparative analysis of using (60)Co beams in intensity-modulated radiation therapy (IMRT). In particular, we evaluate the treatment plan quality obtained with (i) 6 MV, 18 MV and (60)Co IMRT; (ii) different numbers of static multileaf collimator (MLC) delivered (60)Co beams and (iii) a helical tomotherapy (60)Co beam geometry. We employ a convex fluence map optimization (FMO) model, which allows for the comparison of plan quality between different beam energies and configurations for a given case. A total of 25 clinical patient cases that each contain volumetric CT studies, primary and secondary delineated targets, and contoured structures were studied: 5 head-and-neck (H&N), 5 prostate, 5 central nervous system (CNS), 5 breast and 5 lung cases. The DICOM plan data were anonymized and exported to the University of Florida optimized radiation therapy (UFORT) treatment planning system. The FMO problem was solved for each case for 5-71 equidistant beams as well as a helical geometry for H&N, prostate, CNS and lung cases, and for 3-7 equidistant beams in the upper hemisphere for breast cases, all with 6 MV, 18 MV and (60)Co dose models. In all cases, 95% of the target volumes received at least the prescribed dose with clinical sparing criteria for critical organs being met for all structures that were not wholly or partially contained within the target volume. Improvements in critical organ sparing were found with an increasing number of equidistant (60)Co beams, yet were marginal above 9 beams for H&N, prostate, CNS and lung. Breast cases produced similar plans for 3-7 beams. A helical (60)Co beam geometry achieved similar plan quality as static plans with 11 equidistant (60)Co beams. Furthermore, 18 MV plans were initially found not to provide the same target coverage as 6 MV and (60)Co plans; however, adjusting the trade-offs in the optimization model allowed equivalent target coverage for 18 MV. For plans with comparable target coverage, critical structure sparing was best achieved with 6 MV beams followed closely by (60)Co beams, with 18 MV beams requiring significantly increased dose to critical structures. In this paper, we report in detail on a representative set of results from these experiments. The results of the investigation demonstrate the potential for IMRT radiotherapy employing commercially available (60)Co sources and a double-focused MLC. Increasing the number of equidistant beams beyond 9 was not observed to significantly improve target coverage or critical organ sparing and static plans were found to produce comparable plans to those obtained using a helical tomotherapy treatment delivery when optimized using the same well-tuned convex FMO model. While previous studies have shown that 18 MV plans are equivalent to 6 MV for prostate IMRT, we found that the 18 MV beams actually required more fluence to provide similar quality target coverage. PMID:18506074

Fox, Christopher; Romeijn, H Edwin; Lynch, Bart; Men, Chunhua; Aleman, Dionne M; Dempsey, James F

2008-06-21

355

Sensitivity analysis for lexicographic ordering in radiation therapy treatment planning  

PubMed Central

Purpose: To introduce a method to efficiently identify and calculate meaningful tradeoffs between criteria in an interactive IMRT treatment planning procedure. The method provides a systematic approach to developing high-quality radiation therapy treatment plans. Methods: Treatment planners consider numerous dosimetric criteria of varying importance that, when optimized simultaneously through multicriteria optimization, yield a Pareto frontier which represents the set of Pareto-optimal treatment plans. However, generating and navigating this frontier is a time-consuming, nontrivial process. A lexicographic ordering (LO) approach to IMRT uses a physician’s criteria preferences to partition the treatment planning decisions into a multistage treatment planning model. Because the relative importance of criteria optimized in the different stages may not necessarily constitute a strict prioritization, the authors introduce an interactive process, sensitivity analysis in lexicographic ordering (SALO), to allow the treatment planner control over the relative sequential-stage tradeoffs. By allowing this flexibility within a structured process, SALO implicitly restricts attention to and allows exploration of a subset of the Pareto efficient frontier that the physicians have deemed most important. Results: Improvements to treatment plans over a LO approach were found by implementing the SALO procedure on a brain case and a prostate case. In each stage, a physician assessed the tradeoff between previous stage and current stage criteria. The SALO method provided critical tradeoff information through curves approximating the relationship between criteria, which allowed the physician to determine the most desirable treatment plan. Conclusions: The SALO procedure provides treatment planners with a directed, systematic process to treatment plan selection. By following a physician’s prioritization, the treatment planner can avoid wasting effort considering clinically inferior treatment plans. The planner is guided by criteria importance, but given the information necessary to accurately adjust the relative importance at each stage. Through these attributes, the SALO procedure delivers an approach well balanced between efficiency and flexibility. PMID:22755724

Long, T.; Matuszak, M.; Feng, M.; Fraass, B. A.; Ten Haken, R. K.; Romeijn, H. E.

2012-01-01

356

Intensity Modulated Radiation Therapy With Dose Painting to Treat Rhabdomyosarcoma  

SciTech Connect

Purpose: To examine local control and patterns of failure in rhabdomyosarcoma patients treated with intensity modulated radiation therapy (RT) with dose painting (DP-IMRT). Patients and Methods: A total of 41 patients underwent DP-IMRT with chemotherapy for definitive treatment. Nineteen also underwent surgery with or without intraoperative RT. Fifty-six percent had alveolar histologic features. The median interval from beginning chemotherapy to RT was 17 weeks (range, 4-25). Very young children who underwent second-look procedures with or without intraoperative RT received reduced doses of 24-36 Gy in 1.4-1.8-Gy fractions. Young adults received 50.4 Gy to the primary tumor and lower doses of 36 Gy in 1.8-Gy fractions to at-risk lymph node chains. Results: With 22 months of median follow-up, the actuarial local control rate was 90%. Patients aged {<=}7 years who received reduced overall and fractional doses had 100% local control, and young adults had 79% (P=.07) local control. Three local failures were identified in young adults whose primary target volumes had received 50.4 Gy in 1.8-Gy fractions. Conclusions: DP-IMRT with lower fractional and cumulative doses is feasible for very young children after second-look procedures with or without intraoperative RT. DP-IMRT is also feasible in adolescents and young adults with aggressive disease who would benefit from prophylactic RT to high-risk lymph node chains, although dose escalation might be warranted for improved local control. With limited follow-up, it appears that DP-IMRT produces local control rates comparable to those of sequential IMRT in patients with rhabdomyosarcoma.

Yang, Joanna C.; Dharmarajan, Kavita V. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wexler, Leonard H. [Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); La Quaglia, Michael P. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Happersett, Laura [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wolden, Suzanne L., E-mail: woldens@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

2012-11-01

357

Radiation therapy planning and simulation with magnetic resonance images  

NASA Astrophysics Data System (ADS)

We present a system which allows for use of magnetic resonance (MR) images as primary RT workflow modality alone and no longer limits the user to computed tomography data for radiation therapy (RT) planning, simulation and patient localization. The single steps for achieving this goal are explained in detail. For planning two MR data sets, MR1 and MR2 are acquired sequentially. For MR1 a standardized Ultrashort TE (UTE) sequence is used enhancing bony anatomy. The sequence for MR2 is chosen to get optimal contrast for the target and the organs at risk for each individual patient. Both images are naturally in registration, neglecting elastic soft tissue deformations. The planning software first automatically extracts skin and bony anatomy from MR1. The user can semi-automatically delineate target structures and organs at risk based on MR1 or MR2, associate all segmentations with MR1 and create a plan in the coordinate system of MR1. Projections similar to digitally reconstructed radiographs (DRR) enhancing bony anatomy are calculated from the MR1 directly and can be used for iso-center definition and setup verification. Furthermore we present a method for creating a Pseudo-CT data set which assigns electron densities to the voxels of MR1 based on the skin and bone segmentations. The Pseudo-CT is then used for dose calculation. Results from first tests under clinical conditions show the feasibility of the completely MR based workflow in RT for necessary clinical cases. It needs to be investigated in how far geometrical distortions influence accuracy of MR-based RT planning.

Boettger, Thomas; Nyholm, Tufve; Karlsson, Magnus; Nunna, Chandrasekhar; Celi, Juan Carlos

2008-03-01

358

Radiation therapy for children: evolving technologies in the era of ALARA  

Microsoft Academic Search

The evolution of ever more sophisticated oncologic imaging and technologies providing far more precise radiation therapy have\\u000a combined to increase the utilization of sophisticated radiation therapy in childhood cancer. For a majority of children with\\u000a common central nervous system, soft tissue, bone, and dysontogenic neoplasms, local irradiation is fundamental to successful\\u000a multi-disciplinary management. Along with more precise target volume definition

Larry E. Kun; Chris Beltran

2009-01-01

359

Promising survival with three-dimensional conformal radiation therapy for non-small cell lung cancer  

Microsoft Academic Search

Purpose: Local failure is a major obstacle to the cure of locally advanced non small-cell lung cancer. Three-dimensional conformal radiation therapy (3-DCRT) selects optimal treatment parameters to increase dose to tumor and reduce normal tissue dose, potentially representing an enhancement of the therapeutic ratio of radiation therapy for lung cancer. We performed this analysis of 45 non-small cell lung cancer

John Armstrong; Adam Raben; Michael Zelefsky; Michael Burt; Steve Leibel; Chandra Burman; Gerard Kutcher; Louis Harrison; Cathy Hahn; Robert Ginsberg; Valerie Rusch; Mark Kris; Zvi Fuks

1997-01-01

360

Estimation of isodose curves in radiation therapy and related response analysis  

E-print Network

ESTIMATION OF ISODOSE CURVES IN RADIATION THERAPY AND RELATED RESPONSE ANALYSIS A Thesis By JAMES CAMPBELL GOODLETT Submitted to the Graduate College oi' the Texas A@M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE May 1967 Major Subject: Statistic s ESTIMATION OF ISODOSE CURVES IN RADIATION THERAPY AND RELATED RESPONSE ANALYSIS A Thesis By JAMES CAMPBELL GOODLETT Approved as and content by: ( airm n of Committee) Ot~+ (Head...

Goodlett, James Campbell

2012-06-07

361

Progression and complications after external beam radiation therapy for carcinoma of prostate  

SciTech Connect

Sixty patients with prostatic carcinoma localized to the pelvis have been treated by external beam radiation therapy: 2 patients (2%) were Stage A, 12 (20%) Stage B, 14 (23%) Stage C, and 32 (53%) Stage D1. Twenty-two patients received adjuvant therapy (11 estramustine phosphate (Estracyt) and 11 cyclophosphamide (Cytoxan)) after radiation. Progression occurred in 22 patients (37%): 6 (10%) had local recurrence while 16 (27%) failed distally. The incidence of late major complications was 12 percent.

Brausi, M.; Soloway, M.S. (Univ. of Tennessee, Memphis (USA))

1989-09-01

362

Denitrification in human dental plaque  

Microsoft Academic Search

BACKGROUND: Microbial denitrification is not considered important in human-associated microbial communities. Accordingly, metabolic investigations of the microbial biofilm communities of human dental plaque have focused on aerobic respiration and acid fermentation of carbohydrates, even though it is known that the oral habitat is constantly exposed to nitrate (NO3-) concentrations in the millimolar range and that dental plaque houses bacteria that

Frank Schreiber; Peter Stief; Armin Gieseke; Ines M Heisterkamp; Willy Verstraete; Dirk de Beer; Paul Stoodley

2010-01-01

363

Multibeam tomotherapy: A new treatment unit devised for multileaf collimation, intensity-modulated radiation therapy  

Microsoft Academic Search

A fully integrated system for treatment planning, application, and verification for automated multileaf collimator (MLC) based, intensity-modulated, image-guided, and adaptive radiation therapy (IMRT, IGRT and ART, respectively) is proposed. Patient comfort, which was the major development goal, will be achieved through a new unit design and short treatment times. Our device for photon beam therapy will consist of a new

Nils Achterberg; Reinhold G. Mueller

2007-01-01

364

The role of autophagy in sensitizing malignant glioma cells to radiation therapy  

Microsoft Academic Search

Malignant gliomas represent the majority of primary brain tumors. The current standard treatments for malignant gliomas include surgical resection, radiation therapy, and chemotherapy. Radiotherapy, a standard adjuvant therapy, confers some survival advantages, but resistance of the glioma cells to the efficacy of radi- ation limits the success of the treatment. The mechan- isms underlying glioma cell radioresistance have remained elusive.

Wenzhuo Zhuang; Zhenghong Qin; Zhongqin Liang

2009-01-01

365

Treatment of Low-grade Diffuse Astrocytomas by Surgery and Human Fibroblast Interferon without Radiation Therapy  

Microsoft Academic Search

Low-grade diffuse astrocytomas are slowly growing tumors with a relatively long overall survival. However, a substantial proportion undergoes dedifferentiation to a more malignant phenotype. Considerable controversy exists as to the best therapeutic management for patients with such tumors. Over the past decade, we have applied human fibroblast interferon (HFIF) therapy without radiation therapy to low-grade astrocytomas. We investigated 28 patients

Takao Watanabe; Yoichi Katayama; Atsuo Yoshino; Chiaki Komine; Takakazu Yokoyama; Takao Fukushima

2003-01-01

366

Multiscale registration of planning CT and daily cone beam CT images for adaptive radiation therapy  

E-print Network

therapy ART is the incorporation of daily images in the radiotherapy treatment process soMultiscale registration of planning CT and daily cone beam CT images for adaptive radiation therapy images is thus an important component of ART. In this article, the authors report their research

Levy, Doron

367

Hypofractionated Stereotactic Radiation Therapy for Skull Base and Upper Cervical Chordoma and Chondrosarcoma: Preliminary Results  

Microsoft Academic Search

Introduction: Chordoma and chondrosarcoma are rare tumors of the base of the skull and are difficult candidates for surgical treatment. They are also usually resistant to conventional radiation therapy. We report preliminary results of hypofractionated stereotactic radia- tion therapy (SRT) using the Cyberknife system (Accuray Inc., Sunnyvale, Calif., USA) for primary and recurrent chordomas and chondrosarcomas of the skull base

Ho-Shin Gwak; Hyung-Jun Yoo; Sang-Min Youn; Ungkyu Chang; Dong Han Lee; Seong-Yul Yoo; Chang Hun Rhee

2005-01-01

368

Optimization Under Uncertainty: Methods and Applications in Radiation Therapy Weldon Lodwick *  

E-print Network

, the optic nerve, spinal cord, and liver. In the RTP literature there is no agreement on what the objective therapy of tumors and compare their results. Two themes are developed in this study: (1) the modeling The use of particle beams to treat tumors is called the radiation therapy problem (RTP). Beams

Neumaier, Arnold

369

Interstitial lung disease associated with vindesine and radiation therapy for carcinoma of the lung  

SciTech Connect

Diffuse interstitial lung disease and pulmonary fibrosis occurred after the use of vindesine and radiation therapy in a patient with squamous cell carcinoma of the lung. Clinical improvement occurred after the drug was discontinued and corticosteroid therapy was initiated. Review of the literature reveals no previously reported cases of pulmonary toxicity due to vindesine when used alone or in combination with other therapeutic modalities.

Bott, S.J.; Stewart, F.M.; Prince-Fiocco, M.A.

1986-07-01

370

Successful treatment of radiation-induced brain necrosis by hyperbaric oxygen therapy  

Microsoft Academic Search

We describe a 68-year-old man who underwent hyperbaric oxygen (HBO) therapy to manage radiation necrosis of the brain, which developed after two treatments with stereotactic radiosurgery (SRS) to the same lesion. The necrosis was subsequently treated with steroids alone for 2 months; however, he progressed clinically and radiographically. Improvement again was noted with the reinstitution of HBO therapy. This case

Kiyotaka Kohshi; Hajime Imada; Satoshi Nomoto; Raizoh Yamaguchi; Haruhiko Abe; Haruaki Yamamoto

2003-01-01

371

Indications for tomotherapy\\/intensity-modulated radiation therapy in paediatric radiotherapy: extracranial disease  

Microsoft Academic Search

The potential conformality advantages of intensity-modulated radiation therapy (IMRT; TomoTherapy Hi Art TM system) over conventional linear accelerator based therapy was assessed in six consecutive children referred for extracranial radiotherapy. IMRT\\/tomotherapy was considered advantageous for (i) small abdominal tumours, compared with parallel opposed or single portal technology using a conventional linear accelerator, and (ii) re-treatment of an ethmoidal sarcoma, but

P N PLOWMAN; K COOKE; N WALSH

2008-01-01

372

The role of Cobalt-60 in modern radiation therapy: Dose delivery and image guidance  

PubMed Central

The advances in modern radiation therapy with techniques such as intensity-modulated radiation therapy and image-guided radiation therapy (IMRT and IGRT) have been limited almost exclusively to linear accelerators. Investigations of modern Cobalt-60 (Co-60) radiation delivery in the context of IMRT and IGRT have been very sparse, and have been limited mainly to computer-modeling and treatment-planning exercises. In this paper, we report on the results of experiments using a tomotherapy benchtop apparatus attached to a conventional Co-60 unit. We show that conformal dose delivery is possible and also that Co-60 can be used as the radiation source in megavoltage computed tomography imaging. These results complement our modeling studies of Co-60 tomotherapy and provide a strong motivation for continuing development of modern Cobalt-60 treatment devices. PMID:20098559

Schreiner, L. John; Joshi, Chandra P.; Darko, Johnson; Kerr, Andrew; Salomons, Greg; Dhanesar, Sandeep

2009-01-01

373

Plaque Assay for Rickettsia rickettsii  

PubMed Central

A plaque technique for the assay of Rickettsia rickettsii is described. The method employs primary chick or green monkey kidney monolayer cell cultures with either an agarose or special Noble agar overlay. Plaques were counted in 6 days and resultant titers correlated well with ld50 end points obtained by a standard assay in embryonated eggs. Identification of the plaque-forming organisms was accomplished by direct observation of rickettsiae-like bodies in the monolayer lesions, inhibition of plaques by antibiotics, sensitivity of plaques to specific immune serum, and failure to cultivate other microorganisms from the infected cells. Versatility of the test was demonstrated by assaying samples of rickettsiae from several different sources commonly used in our laboratory. These included infected yolk sacs, various cell cultures, and infected guinea pig tissue. Sufficient numbers of viable rickettsiae were present in the cells of a single lesion to permit direct recovery. Images PMID:4977475

Weinberg, Edmund H.; Stakebake, Jack R.; Gerone, Peter J.

1969-01-01

374

Plaque assay for Rickettsia rickettsii.  

PubMed

A plaque technique for the assay of Rickettsia rickettsii is described. The method employs primary chick or green monkey kidney monolayer cell cultures with either an agarose or special Noble agar overlay. Plaques were counted in 6 days and resultant titers correlated well with ld(50) end points obtained by a standard assay in embryonated eggs. Identification of the plaque-forming organisms was accomplished by direct observation of rickettsiae-like bodies in the monolayer lesions, inhibition of plaques by antibiotics, sensitivity of plaques to specific immune serum, and failure to cultivate other microorganisms from the infected cells. Versatility of the test was demonstrated by assaying samples of rickettsiae from several different sources commonly used in our laboratory. These included infected yolk sacs, various cell cultures, and infected guinea pig tissue. Sufficient numbers of viable rickettsiae were present in the cells of a single lesion to permit direct recovery. PMID:4977475

Weinberg, E H; Stakebake, J R; Gerone, P J

1969-05-01

375

Stereotactic body radiation therapy planning with duodenal sparing using volumetric-modulated arc therapy vs intensity-modulated radiation therapy in locally advanced pancreatic cancer: a dosimetric analysis.  

PubMed

Stereotactic body radiation therapy (SBRT) achieves excellent local control for locally advanced pancreatic cancer (LAPC), but may increase late duodenal toxicity. Volumetric-modulated arc therapy (VMAT) delivers intensity-modulated radiation therapy (IMRT) with a rotating gantry rather than multiple fixed beams. This study dosimetrically evaluates the feasibility of implementing duodenal constraints for SBRT using VMAT vs IMRT. Non-duodenal sparing (NS) and duodenal-sparing (DS) VMAT and IMRT plans delivering 25Gy in 1 fraction were generated for 15 patients with LAPC. DS plans were constrained to duodenal Dmax of<30Gy at any point. VMAT used 1 360° coplanar arc with 4° spacing between control points, whereas IMRT used 9 coplanar beams with fixed gantry positions at 40° angles. Dosimetric parameters for target volumes and organs at risk were compared for DS planning vs NS planning and VMAT vs IMRT using paired-sample Wilcoxon signed rank tests. Both DS VMAT and DS IMRT achieved significantly reduced duodenal Dmean, Dmax, D1cc, D4%, and V20Gy compared with NS plans (all p?0.002). DS constraints compromised target coverage for IMRT as demonstrated by reduced V95% (p = 0.01) and Dmean (p = 0.02), but not for VMAT. DS constraints resulted in increased dose to right kidney, spinal cord, stomach, and liver for VMAT. Direct comparison of DS VMAT and DS IMRT revealed that VMAT was superior in sparing the left kidney (p<0.001) and the spinal cord (p<0.001), whereas IMRT was superior in sparing the stomach (p = 0.05) and the liver (p = 0.003). DS VMAT required 21% fewer monitor units (p<0.001) and delivered treatment 2.4 minutes faster (p<0.001) than DS IMRT. Implementing DS constraints during SBRT planning for LAPC can significantly reduce duodenal point or volumetric dose parameters for both VMAT and IMRT. The primary consequence of implementing DS constraints for VMAT is increased dose to other organs at risk, whereas for IMRT it is compromised target coverage. These findings suggest clinical situations where each technique may be most useful if DS constraints are to be employed. PMID:23540490

Kumar, Rachit; Wild, Aaron T; Ziegler, Mark A; Hooker, Ted K; Dah, Samson D; Tran, Phuoc T; Kang, Jun; Smith, Koren; Zeng, Jing; Pawlik, Timothy M; Tryggestad, Erik; Ford, Eric; Herman, Joseph M

2013-01-01

376

Stereotactic body radiation therapy planning with duodenal sparing using volumetric-modulated arc therapy vs intensity-modulated radiation therapy in locally advanced pancreatic cancer: A dosimetric analysis  

SciTech Connect

Stereotactic body radiation therapy (SBRT) achieves excellent local control for locally advanced pancreatic cancer (LAPC), but may increase late duodenal toxicity. Volumetric-modulated arc therapy (VMAT) delivers intensity-modulated radiation therapy (IMRT) with a rotating gantry rather than multiple fixed beams. This study dosimetrically evaluates the feasibility of implementing duodenal constraints for SBRT using VMAT vs IMRT. Non–duodenal sparing (NS) and duodenal-sparing (DS) VMAT and IMRT plans delivering 25 Gy in 1 fraction were generated for 15 patients with LAPC. DS plans were constrained to duodenal D{sub max} of<30 Gy at any point. VMAT used 1 360° coplanar arc with 4° spacing between control points, whereas IMRT used 9 coplanar beams with fixed gantry positions at 40° angles. Dosimetric parameters for target volumes and organs at risk were compared for DS planning vs NS planning and VMAT vs IMRT using paired-sample Wilcoxon signed rank tests. Both DS VMAT and DS IMRT achieved significantly reduced duodenal D{sub mean}, D{sub max}, D{sub 1cc}, D{sub 4%}, and V{sub 20} {sub Gy} compared with NS plans (all p?0.002). DS constraints compromised target coverage for IMRT as demonstrated by reduced V{sub 95%} (p = 0.01) and D{sub mean} (p = 0.02), but not for VMAT. DS constraints resulted in increased dose to right kidney, spinal cord, stomach, and liver for VMAT. Direct comparison of DS VMAT and DS IMRT revealed that VMAT was superior in sparing the left kidney (p<0.001) and the spinal cord (p<0.001), whereas IMRT was superior in sparing the stomach (p = 0.05) and the liver (p = 0.003). DS VMAT required 21% fewer monitor units (p<0.001) and delivered treatment 2.4 minutes faster (p<0.001) than DS IMRT. Implementing DS constraints during SBRT planning for LAPC can significantly reduce duodenal point or volumetric dose parameters for both VMAT and IMRT. The primary consequence of implementing DS constraints for VMAT is increased dose to other organs at risk, whereas for IMRT it is compromised target coverage. These findings suggest clinical situations where each technique may be most useful if DS constraints are to be employed.

Kumar, Rachit; Wild, Aaron T.; Ziegler, Mark A.; Hooker, Ted K.; Dah, Samson D.; Tran, Phuoc T.; Kang, Jun; Smith, Koren; Zeng, Jing [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States); Pawlik, Timothy M. [Department of Surgery, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Tryggestad, Erik [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States); Ford, Eric [Department of Radiation Oncology, Fred Hutchinson Cancer Center, University of Washington, Seattle, WA (United States); Herman, Joseph M., E-mail: jherma15@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States)

2013-10-01

377

Stereotactic body radiation therapy planning with duodenal sparing using volumetric-modulated arc therapy vs intensity-modulated radiation therapy in locally advanced pancreatic cancer: A dosimetric analysis  

PubMed Central

Stereotactic body radiation therapy (SBRT) achieves excellent local control for locally advanced pancreatic cancer (LAPC), but may increase late duodenal toxicity. Volumetric-modulated arc therapy (VMAT) delivers intensity-modulated radiation therapy (IMRT) with a rotating gantry rather than multiple fixed beams. This study dosimetrically evaluates the feasibility of implementing duodenal constraints for SBRT using VMAT vs IMRT. Non–duodenal sparing (NS) and duodenal-sparing (DS) VMAT and IMRT plans delivering 25 Gy in 1 fraction were generated for 15 patients with LAPC. DS plans were constrained to duodenal Dmax of <30 Gy at any point. VMAT used 1 360° coplanar arc with 4° spacing between control points, whereas IMRT used 9 coplanar beams with fixed gantry positions at 40° angles. Dosimetric parameters for target volumes and organs at risk were compared for DS planning vs NS planning and VMAT vs IMRT using paired-sample Wilcoxon signed rank tests. Both DS VMAT and DS IMRT achieved significantly reduced duodenal Dmean, Dmax, D1cc, D4%, and V20 Gy compared with NS plans (all p ? 0.002). DS constraints compromised target coverage for IMRT as demonstrated by reduced V95% (p = 0.01) and Dmean (p = 0.02), but not for VMAT. DS constraints resulted in increased dose to right kidney, spinal cord, stomach, and liver for VMAT. Direct comparison of DS VMAT and DS IMRT revealed that VMAT was superior in sparing the left kidney (p < 0.001) and the spinal cord (p < 0.001), whereas IMRT was superior in sparing the stomach (p = 0.05) and the liver (p = 0.003). DS VMAT required 21% fewer monitor units (p < 0.001) and delivered treatment 2.4 minutes faster (p < 0.001) than DS IMRT. Implementing DS constraints during SBRT planning for LAPC can significantly reduce duodenal point or volumetric dose parameters for both VMAT and IMRT. The primary consequence of implementing DS constraints for VMAT is increased dose to other organs at risk, whereas for IMRT it is compromised target coverage. These findings suggest clinical situations where each technique may be most useful if DS constraints are to be employed. PMID:23540490

Kumar, Rachit; Wild, Aaron T.; Ziegler, Mark A.; Hooker, Ted K.; Dah, Samson D.; Tran, Phuoc T.; Kang, Jun; Smith, Koren; Zeng, Jing; Pawlik, Timothy M.; Tryggestad, Erik; Ford, Eric; Herman, Joseph M.

2014-01-01

378

Fetal radiation monitoring and dose minimization during intensity modulated radiation therapy for glioblastoma in pregnancy.  

PubMed

We examined the fetal dose from irradiation of glioblastoma during pregnancy using intensity modulated radiation therapy (IMRT), and describe fetal dose minimization using mobile shielding devices. A case report is described of a pregnant woman with glioblastoma who was treated during the third trimester of gestation with 60 Gy of radiation delivered via a 6 MV photon IMRT plan. Fetal dose without shielding was estimated using an anthropomorphic phantom with ion chamber and diode measurements. Clinical fetal dose with shielding was determined with optically stimulated luminescent dosimeters and ion chamber. Clinical target volume (CTV) and planning target volume (PTV) coverage was 100 and 98 % receiving 95 % of the prescription dose, respectively. Normal tissue tolerances were kept below quantitative analysis of normal tissue effects in the clinic (QUANTEC) recommendations. Without shielding, anthropomorphic phantom measurements showed a cumulative fetal dose of 0.024 Gy. In vivo measurements with shielding in place demonstrated a cumulative fetal dose of 0.016 Gy. The fetal dose estimated without shielding was 0.04 % and with shielding was 0.026 % of the target dose. In vivo estimation of dose equivalent received by the fetus was 24.21 mSv. Using modern techniques, brain irradiation can be delivered to pregnant patients in the third trimester with very low measured doses to the fetus, without compromising target coverage or normal tissue dose constraints. Fetal dose can further be reduced with the use of shielding devices, in keeping with the principle of as low as reasonably achievable. PMID:25096798

Horowitz, David P; Wang, Tony J C; Wuu, Cheng-Shie; Feng, Wenzheng; Drassinower, Daphnie; Lasala, Anita; Pieniazek, Radoslaw; Cheng, Simon; Connolly, Eileen P; Lassman, Andrew B

2014-11-01

379

Tobacco Smoking During Radiation Therapy for Head-and-Neck Cancer Is Associated With Unfavorable Outcome  

SciTech Connect

Purpose: To evaluate the effect of continued cigarette smoking among patients undergoing radiation therapy for head-and-neck cancer by comparing the clinical outcomes among active smokers and quitters. Methods and Materials: A review of medical records identified 101 patients with newly diagnosed squamous cell carcinoma of the head and neck who continued to smoke during radiation therapy. Each active smoker was matched to a control patient who had quit smoking before initiation of radiation therapy. Matching was based on tobacco history (pack-years), primary site, age, sex, Karnofsky Performance Status, disease stage, radiation dose, chemotherapy use, year of treatment, and whether surgical resection was performed. Outcomes were compared by use of Kaplan-Meier analysis. Normal tissue effects were graded according to the Radiation Therapy Oncology Group/European Organization for the Treatment of Cancer toxicity criteria. Results: With a median follow-up of 49 months, active smokers had significantly inferior 5-year overall survival (23% vs. 55%), locoregional control (58% vs. 69%), and disease-free survival (42% vs. 65%) compared with the former smokers who had quit before radiation therapy (p < 0.05 for all). These differences remained statistically significant when patients treated by postoperative or definitive radiation therapy were analyzed separately. The incidence of Grade 3 or greater late complications was also significantly increased among active smokers compared with former smokers (49% vs. 31%, p = 0.01). Conclusions: Tobacco smoking during radiation therapy for head-and-neck cancer is associated with unfavorable outcomes. Further studies analyzing the biologic and molecular reasons underlying these differences are planned.

Chen, Allen M., E-mail: allen.chen@ucdmc.ucdavis.ed [Department of Radiation Oncology, University of California Davis Cancer Center, Sacramento, CA (United States); Chen, Leon M.; Vaughan, Andrew; Sreeraman, Radhika [Department of Radiation Oncology, University of California Davis Cancer Center, Sacramento, CA (United States); Farwell, D. Gregory; Luu, Quang [Department of Otolaryngology-Head and Neck Surgery, University of California Davis Cancer Center, Sacramento, CA (United States); Lau, Derick H. [Department of Medical Oncology, University of California Davis Cancer Center, Sacramento, CA (United States); Stuart, Kerri; Purdy, James A.; Vijayakumar, Srinivasan [Department of Radiation Oncology, University of California Davis Cancer Center, Sacramento, CA (United States)

2011-02-01

380

Ultrasound Thermometry for Therapy-level Radiation Dosimetry  

Microsoft Academic Search

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

Courtney Taylor

2010-01-01

381

Radiation therapy of tumors of the central nervous system in childhood.  

PubMed

The results of radiation therapy for CNS tumors of childhood are presented and discussed according to histologic type. In this material the 5-year recurrence-free survival rates were about 35% for medulloblastomas, 48% for the hypothalamic and brain stem tumors, 86% for lowgrade ependymomas, and 57% for germinomas. Complications or CNS injury from irradiation were rare and the quality of life in survivors was generally good. Current methods of radiation therapy may possibly improve these results. Tumors of the CNS in children do not necessarily carry a hopeless prognosis; aggressive therapy is indicated. PMID:163143

Sheline, G E

1975-03-01

382

Quantitative evaluation on the accuracy of image registration methods in SPECT guided radiation therapy for lung cancer patients  

E-print Network

therapy for lung cancer patients Lingshu Yin*1,2 ; Lisa Tang3 ; Ghassan Hamarneh3 ; Vitali Moiseenko1 in SPECT guided radiation therapy (RT) treatment planning. Methods and Materials: Five lung cancer patients perfusion SPECT into radiation therapy (RT) treatment planning for patients with lung cancer [1, 2]. SPECT

Hamarneh, Ghassan

383

Patterns of failure and results of preoperative irradiation vs radiation therapy alone in carcinoma of the pyriform sinus  

Microsoft Academic Search

From 1968 to 1977, 53 of 78 patients with carcinoma of the pyriform sinus completed planned therapy and were eligible for followup a minimum of two years. Of the 53, 35 (66%) were treated with high dose preoperative irradiation and surgery, while 18 (33%) were treated with radiation therapy alone. The radiation therapy fields for both groups were reviewed for

Roger W Byhardt; James D Cox

1980-01-01

384

Continuing Education Course Use of CT and PET in Radiation Therapy  

Microsoft Academic Search

The modern practice of radiation therapy relies on volumetric patient images. Computed tomography (CT) imaging has been the primary imaging modality used in radiation oncology for over two decades. However, magnetic resonance imaging (MRI) and positron emission tomography (PET) are increasingly becoming an important component of the treatment planning process. CT studies provide information not only about target volumes but

Sasa Mutic

385

The relationship between educational preparation and performance on the ARRT examination in radiation therapy  

Microsoft Academic Search

Purpose: To determine if graduates of different types of educational programs obtain similar scores on the Examination in Radiation Therapy administered by the American Registry of Radiologic Technologists. The results will help inform discussions regarding educational requirements for radiation therapists.Methods and Materials: Test scores were obtained for 531 candidates who had taken the examination for the first time in 1997,

Mark R Raymond; Charles M Washington

2002-01-01

386

Hyperbaric oxygen therapy for late sequelae in women receiving radiation after breast-conserving surgery  

Microsoft Academic Search

Purpose: Persisting symptomatology after breast-conserving surgery and radiation is frequently reported. In most cases, symptoms in the breast resolve without further treatment. In some instances, however, pain, erythema, and edema can persist for years and can impact the patient’s quality of life. Hyperbaric oxygen therapy was shown to be effective as treatment for late radiation sequelae. The objective of this

Ulrich M Carl; John J Feldmeier; Gerd Schmitt; K. Axel Hartmann

2001-01-01

387

Dana-Farber Cancer Institute and Children's Hospital Boston study identifies possible therapy for radiation sickness:  

Cancer.gov

A combination of two drugs may alleviate radiation sickness in people who have been exposed to high levels of radiation, even when the therapy is given a day after the exposure occurred, according to a study conducted in mice, led by scientists from Dana-Farber Cancer Institute and Children's Hospital Boston.

388

Dosimetric comparison of volumetric modulated arc therapy and intensity-modulated radiation therapy for pancreatic malignancies  

SciTech Connect

Volumetric-modulated arc therapy (VMAT) has been previously evaluated for several tumor sites and has been shown to provide significant dosimetric and delivery benefits when compared with intensity-modulated radiation therapy (IMRT). To date, there have been no published full reports on the benefits of VMAT use in pancreatic patients compared with IMRT. Ten patients with pancreatic malignancies treated with either IMRT or VMAT were retrospectively identified. Both a double-arc VMAT and a 7-field IMRT plan were generated for each of the 10 patients using the same defined tumor volumes, organs at risk (OAR) volumes, dose, fractionation, and optimization constraints. The planning tumor volume (PTV) maximum dose (55.8 Gy vs. 54.4 Gy), PTV mean dose (53.9 Gy vs. 52.1 Gy), and conformality index (1.11 vs. 0.99) were statistically similar between the IMRT and VMAT plans, respectively. The VMAT plans had a statistically significant reduction in monitor units compared with the IMRT plans (1109 vs. 498, p < 0.001). In addition, the doses to the liver, small bowel, and spinal cord were comparable between the IMRT and VMAT plans. However, the VMAT plans demonstrated a statistically significant reduction in the mean left kidney V{sub 25} (9.4 Gy vs. 2.3 Gy, p = 0.018), mean right kidney V{sub 15} (53.4 Gy vs. 45.9 Gy, p = 0.035), V{sub 20} (32.2 Gy vs. 25.5 Gy, p = 0.016), and V{sub 25} (21.7 Gy vs. 14.9 Gy, p = 0.001). VMAT was investigated in patients with pancreatic malignancies and compared with the current standard of IMRT. VMAT was found to have similar or improved dosimetric parameters for all endpoints considered. Specifically, VMAT provided reduced monitor units and improved bilateral kidney normal tissue dose. The clinical relevance of these benefits in the context of pancreatic cancer patients, however, is currently unclear and requires further investigation.

Ali, Arif N., E-mail: aali24@emory.edu [Department of Radiation Oncology, Emory University, Atlanta, GA (United States); Winship Cancer Institute, Emory University, Atlanta, GA (United States); Dhabaan, Anees H.; Jarrio, Christie S.; Siddiqi, Arsalan K.; Landry, Jerome C. [Department of Radiation Oncology, Emory University, Atlanta, GA (United States); Winship Cancer Institute, Emory University, Atlanta, GA (United States)

2012-10-01

389

Adaptive Stereotactic Body Radiation Therapy Planning for Lung Cancer  

SciTech Connect

Purpose: To investigate the dosimetric effects of adaptive planning on lung stereotactic body radiation therapy (SBRT). Methods and Materials: Forty of 66 consecutive lung SBRT patients were selected for a retrospective adaptive planning study. CBCT images acquired at each fraction were used for treatment planning. Adaptive plans were created using the same planning parameters as the original CT-based plan, with the goal to achieve comparable comformality index (CI). For each patient, 2 cumulative plans, nonadaptive plan (P{sub NON}) and adaptive plan (P{sub ADP}), were generated and compared for the following organs-at-risks (OARs): cord, esophagus, chest wall, and the lungs. Dosimetric comparison was performed between P{sub NON} and P{sub ADP} for all 40 patients. Correlations were evaluated between changes in dosimetric metrics induced by adaptive planning and potential impacting factors, including tumor-to-OAR distances (d{sub T-OAR}), initial internal target volume (ITV{sub 1}), ITV change (?ITV), and effective ITV diameter change (?d{sub ITV}). Results: 34 (85%) patients showed ITV decrease and 6 (15%) patients showed ITV increase throughout the course of lung SBRT. Percentage ITV change ranged from ?59.6% to 13.0%, with a mean (±SD) of ?21.0% (±21.4%). On average of all patients, P{sub ADP} resulted in significantly (P=0 to .045) lower values for all dosimetric metrics. ?d{sub ITV}/d{sub T-OAR} was found to correlate with changes in dose to 5 cc (?D5cc) of esophagus (r=0.61) and dose to 30 cc (?D30cc) of chest wall (r=0.81). Stronger correlations between ?d{sub ITV}/d{sub T-OAR} and ?D30cc of chest wall were discovered for peripheral (r=0.81) and central (r=0.84) tumors, respectively. Conclusions: Dosimetric effects of adaptive lung SBRT planning depend upon target volume changes and tumor-to-OAR distances. Adaptive lung SBRT can potentially reduce dose to adjacent OARs if patients present large tumor volume shrinkage during the treatment.

Qin, Yujiao [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Zhang, Fan [Occupational and Environmental Safety Office, Duke University Medical Center, Durham, North Carolina (United States); Yoo, David S.; Kelsey, Chris R. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Yin, Fang-Fang [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Cai, Jing, E-mail: jing.cai@duke.edu [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)

2013-09-01

390

[Evaluation of the therapeutic response after stereotactic body radiation therapy for liver tumors].  

PubMed

Stereotactic body radiation therapy takes more and more an important place in the therapeutic arsenal of primitive and secondary liver tumours. The administration of ablative radiation doses can result in specific changes to both the tumour and the healthy hepatic parenchyma, relative to conventional radiation therapy, making the assessment of local changes after stereotactic body radiation therapy, in terms of local control and reaction of healthy tissue, often difficult. It is mandatory to standardize and simplify our evaluation criteria to benefit from a better understanding of the effectiveness of this new treatment modality and allow better reproducibility of available imaging exams. This article presents a literature review of the various radiological changes observed after stereotactic body radiation therapy for liver tumours according to the multiple assessment methods used to determine local control. From the data available, we recommend using modified RECIST criteria proposed by the American Association for the Study of Liver Diseases (AASLD), as objective and relevant criteria of local control after stereotactic body radiation therapy for liver tumours. PMID:24811896

Janoray, G; Barillot, I; Calais, G

2014-01-01

391

Measurement of the dose equivalent of leakage radiation through an isocentric gantry used for neutron therapy.  

PubMed

The leakage radiation through the shielding on an isocentric gantry of a neutron therapy machine was measured with a Rossi-type proportional counter. The dose equivalent of the leakage radiation was determined at two positions: (1) in the plane of the patient and (2) in the plane of the target. The dose equivalent of the leakage radiation is approximately the same as the leakage of a high-energy x-ray linac. PMID:3211056

Horton, J L; Stafford, P M; Kliauga, P

1988-01-01

392

Dose escalation with three-dimensional conformal radiation therapy affects the outcome in prostate cancer  

Microsoft Academic Search

Purpose: Three-dimensional conformal radiation therapy (3D-CRT) is a technique designed to deliver prescribed radiation doses to localized tumors with high precision, while effectively excluding the surrounding normal tissues. It facilitates tumor dose escalation which should overcome the relative resistance of tumor clonogens to conventional radiation dose levels. The present study was undertaken to test this hypothesis in patients with clinically

MichaelJ Zelefsky; StevenA Leibel; PaulB Gaudin; GeraldJ Kutcher; NeilE Fleshner; E. S Venkatramen; VictorE Reuter; WilliamR Fair; C. Clifton Ling; Zvi Fuks

1998-01-01

393

Decision Regret in Men Undergoing Dose-Escalated Radiation Therapy for Prostate Cancer  

SciTech Connect

Purpose: Decision regret (DR) is a negative emotion associated with medical treatment decisions, and it is an important patient-centered outcome after therapy for localized prostate cancer. DR has been found to occur in up to 53% of patients treated for localized prostate cancer, and it may vary depending on treatment modality. DR after modern dose-escalated radiation therapy (DE-RT) has not been investigated previously, to our knowledge. Our primary aim was to evaluate DR in a cohort of patients treated with DE-RT. Methods and Materials: We surveyed 257 consecutive patients with localized prostate cancer who had previously received DE-RT, by means of a validated questionnaire. Results: There were 220 responses (85.6% response rate). Image-guided intensity modulated radiation therapy was given in 85.0% of patients and 3-dimensional conformal radiation therapy in 15.0%. Doses received included 73.8 Gy (34.5% patients), 74 Gy (53.6%), and 76 Gy (10.9%). Neoadjuvant androgen deprivation (AD) was given in 51.8% of patients and both neoadjuvant and adjuvant AD in 34.5%. The median follow-up time was 23 months (range, 12-67 months). In all, 3.8% of patients expressed DR for their choice of treatment. When asked whether they would choose DE-RT or AD again, only 0.5% probably or definitely would not choose DE-RT again, compared with 8.4% for AD (P<.01). Conclusion: Few patients treated with modern DE-RT express DR, with regret appearing to be lower than in previously published reports of patients treated with radical prostatectomy or older radiation therapy techniques. Patients experienced more regret with the AD component of treatment than with the radiation therapy component, with implications for informed consent. Further research should investigate regret associated with individual components of modern therapy, including AD, radiation therapy and surgery.

Steer, Anna N. [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia)] [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia); Aherne, Noel J., E-mail: noel.aherne@ncahs.health.nsw.gov.au [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia); Rural Clinical School Faculty of Medicine, University of New South Wales, Coffs Harbour (Australia); Gorzynska, Karen; Hoffman, Matthew; Last, Andrew; Hill, Jacques [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia)] [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia); Shakespeare, Thomas P. [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia) [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia); Rural Clinical School Faculty of Medicine, University of New South Wales, Coffs Harbour (Australia)

2013-07-15

394

[Occurrence of organizing pneumonia after radiation therapy for postoperative breast cancer].  

PubMed

Three cases of organizing pneumonia (OP) that occurred after planned radiation therapy for postoperative breast cancer are reported. All patients received tangential radiation therapy and adjuvant tamoxifen (TAM) for postoperative breast cancer. Two patients developed fever and cough; one was asymptomatic. Chest radiography and computed tomography demonstrated peripheral alveolar opacities outside the radiation field. Bronchoalveolar lavage showed an elevated total cell count with a high percentage of lymphocytes, as well as elevated eosinophil levels in two cases. Transbronchial lung biopsy revealed a histologic pattern consistent with organizing pneumonia. For the two symptomatic cases, treatment with corticosteroids reduced clinical symptoms promptly and improved imaging findings. The single asymptomatic case improved without treatment. The number of such reported cases has increased in recent years, but the etiology is unclear. In the three cases presented, TAM combined with radiation therapy may have been the cause of the OP. PMID:21735749

Kishikawa, Takayuki; Imadachi, Hiroko; Hirano, Katsuji; Nakashima, Shota; Sasaki, Eisuke; Kinoshita, Akitoshi

2011-06-01

395

Establishing a Palliative Care Team (PCT) in Radiation Therapy: The British Columbia Cancer Agency Vancouver Center Experience  

Microsoft Academic Search

The radiation therapy department at the Vancouver Cancer Center, British Columbia, Canada, has introduced a Palliative Care Team (PCT). The PCT consists of a group of radiation therapists dedicated to the care of patients undergoing palliative radiation therapy. The PCT is responsible for the simulation, education, dose calculations, verification system data entry and treatment of each palliative patient. Participation in

Craig Elith

2006-01-01

396

Hyperbaric oxygen therapy for carcinoma of the cervix - Stages IIB, IIIA, IIIB, and IVA: results of a randomized study by the radiation therapy oncology group  

Microsoft Academic Search

A total of 65 patients with Stage IIB, IIIA, IIIB or IVA carcinoma of the cervix were randomized to receive conventional radiation therapy in air or hyperbaric oxygen therapy with radiation at optimal schedules. Seven patients could not be evaluated. Of the 19 patients treated in oxygen, 14 (73%) were living or had died without evidence of disease. Of the

Luther W. Brady; Henry P. Plenk; James A. Hanley; John R. Glassburn; Simon Kramer; Robert G. Parker

1981-01-01

397

Bevacizumab as Therapy for Radiation Necrosis in Four Children With Pontine Gliomas  

SciTech Connect

Purpose: Diffuse pontine gliomas are a pediatric brain tumor that is fatal in nearly all patients. Given the poor prognosis for patients with this tumor, their quality of life is very important. Radiation therapy provides some palliation, but can result in radiation necrosis and associated neurologic decline. The typical treatment for this necrosis is steroid therapy. Although the steroids are effective, they have numerous side effects that can often significantly compromise quality of life. Bevacizumab, an antibody against vascular endothelial growth factor, has been suggested as a treatment for radiation necrosis. We report on our initial experience with bevacizumab therapy for radiation necrosis in pediatric pontine gliomas. Materials and Methods: Four children with pontine gliomas treated at the Children's Hospital in Denver and the University of Colorado Denver developed evidence of radiation necrosis both clinically and on imaging. Those 4 children then received bevacizumab as a treatment for the radiation necrosis. We reviewed the clinical outcome and imaging findings. Results: After bevacizumab therapy, 3 children had significant clinical improvement and were able to discontinue steroid use. One child continued to decline, and, in retrospect, had disease progression, not radiation necrosis. In all cases, bevacizumab was well tolerated. Conclusions: In children with pontine gliomas, bevacizumab may provide both therapeutic benefit and diagnostic information. More formal evaluation of bevacizumab in these children is needed.

Liu, Arthur K., E-mail: arthur.liu@ucdenver.ed [University of Colorado Denver, Department of Radiation Oncology, Aurora, CO (United States); Macy, Margaret E.; Foreman, Nicholas K. [Children's Hospital, Denver, Department of Neuro-Oncology, Aurora, CO (United States)

2009-11-15

398

Radiation Physics and Chemistry in Heavy-ion Cancer Therapy  

Microsoft Academic Search

Heavy ions, such as carbon and oxygen ions, are classified as high-LET radiations, and produce a characteristic dose-depth distribution different from that of low-LET radiations such as g-rays, x- rays and electrons. Heavy ions lose less energy at the entrance to an irradiated biological system up to some depth than the low-LET radiations, while they deposit a large amount of

I. Krajcar Broniæa; M. Kimura

399

Androgen ablation in addition to radiation therapy for prostate cancer: is there true benefit?  

PubMed

Prostate cancer patients may now be identified as having a high risk of failing single-modality treatment based on pretreatment prostate specific antigen (PSA), Gleason score, and palpable stage. In particular, a PSA greater than 20 ng/mL portends a biochemical failure rate of 50% to 80% when radiation therapy, surgery, or androgen ablation is administered individually. A number of randomized trials as well as retrospective data show that failure rates are significantly reduced by combining androgen ablation and radiation. The improved results, however, are complicated by the ability to salvage radiation alone-treated patients with androgen ablation and the possibility of less effective salvage (or no effective salvage in the case of permanent androgen ablation) for patients treated with androgen ablation plus radiation. Thus, survival, which is obscured by high rates of intercurrent deaths in this elderly population, is the most important end point in such studies. Two randomized trials, one from the Radiation Therapy Oncology Group (RTOG) and one from the European Organization for Research on Treatment for Cancer (EORTC), of radiation therapy plus adjuvant (as opposed to neoadjuvant) androgen ablation have reported survival gains over radiation therapy alone. In contrast, one neoadjuvant trial from the RTOG failed to show a survival benefit when androgen ablation was added to radiation therapy. In this study, however, androgen ablation was administered for only 4 to 5 months, which may be insufficient. The weight of the evidence to date indicates a true benefit with androgen ablation plus radiation therapy over radiation therapy alone. There are clearly many unanswered questions concerning the optimal timing of androgen ablation and radiation therapy (neoadjuvant versus adjuvant), length of time that androgen ablation should be administered (6 months versus 3 years versus permanent), type of androgen ablation (total androgen ablation or not), and appropriate patient population (definition of high risk). The planned future clinical trials will address many of these i