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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

Radiation Therapy  

MedlinePLUS

Radiation Therapy Radiation therapy (sometimes referred to as radiotherapy, x-ray therapy or irradiation) has been used to treat many types of cancer for more than 100 years. Radiation therapy refers to the careful use of various ...

3

Radiation Therapy  

MedlinePLUS

... weeks. New Techniques Newer radiation techniques such as proton beam radiotherapy, which uses a different form of ... requiring many more beams than conventional radiation therapy. Proton Beam Therapy compared to traditional photon beam radiation, ...

4

Radiation Therapy  

MedlinePLUS

... for e-updates Please leave this field empty Radiation Therapy SHARE Share on Facebook Preview your comments ... Treatment and Care > Treatments Listen The goal of radiation therapy is to destroy or stop brain tumor ...

5

Radiation Therapy  

MedlinePLUS

... treatment for kids or adults who have cancer . Radiation to Treat Cancer Cancer is a disease that ... don't get it very often. How Is Radiation Given? Cancer can be treated with radiation therapy ...

6

Radiation Therapy  

MedlinePLUS

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

7

Radiation therapy  

MedlinePLUS

Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells. ... most common form. This method carefully aims high-powered x-rays or particles directly at the tumor ...

8

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

9

Gallbladder Cancer: Radiation Therapy  

MedlinePLUS

... gallbladder cancer Next Topic Chemotherapy for gallbladder cancer Radiation therapy for gallbladder cancer Radiation therapy uses high- ... higher dose to the cancer areas. Uses of radiation therapy Radiation therapy can be used in several ...

10

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

11

Rhabdomyosarcoma: Radiation Therapy  

MedlinePLUS

... dose chemotherapy and stem cell transplants for rhabdomyosarcoma Radiation therapy for rhabdomyosarcoma Radiation therapy uses high-energy ... so they won’t move during treatment. Newer radiation techniques Some newer techniques can help doctors aim ...

12

Radiation related complications after ruthenium plaque radiotherapy of uveal melanoma  

Microsoft Academic Search

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),

P Summanen; I Immonen; T Kivelä; P Tommila; J Heikkonen; A Tarkkanen

1996-01-01

13

Synchrotron microbeam radiation therapy.  

E-print Network

??This thesis presents interdisciplinary, collaborative research in the field of synchrotron microbeam radiation therapy (MRT). Synchrotron MRT is an experimental radiotherapy technique under consideration for… (more)

Crosbie, Jeffrey

2008-01-01

14

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 is radiation therapy. Gunnar Zagars, M.D.: There are different forms of radiation for prostate ...

15

Prostate Cancer (Radiation Therapy)  

MedlinePLUS

... control the cancer. If I choose surgery, will radiation treatment still be required? If your surgery is ... option with your physician team. If I choose radiation therapy, will surgical treatment still be an option? ...

16

Vulnerable Plaque: From Bench to Bedside; Local Pacification Versus Systemic Therapy  

PubMed Central

Critical coronary stenoses accounts for a small proportion of acute coronary syndromes and sudden death. The majority are caused by coronary thromboses that arise from a nonangiographically obstructive atheroma. Recent developments in noninvasive imaging of so-called vulnerable plaques created opportunities to direct treatment to prevent morbidity and mortality associated with these high-risk lesions. This review covers therapy employed in the past, present, and potentially in the future as the natural history of plaque assessment unfolds. PMID:23439781

Kasim, Sazzli; Moran, Darragh; McFadden, Eugene

2012-01-01

17

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

18

Radiation Therapy: Additional Treatment Options  

MedlinePLUS

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

19

Bile Duct (Cholangiocarcinoma) Cancer: Radiation Therapy  

MedlinePLUS

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

20

Changes in height of choroidal melanomas after plaque therapy.  

PubMed Central

Serial ultrasonic measurements of 82 uveal melanomas treated with brachytherapy plaques (cobalt-60 and iodine-125) and followed up for up to 141 months revealed that no two patients had identical patterns of change. The mean absolute change in tumour height after treatment was 1.8 mm at six months, 5.6 mm at 48 months for large tumours, and 0.9 and 1.9 mm for medium sized tumours. Eighty of the 82 patients fell into one of three patterns of response: 57 patients had a decrease in height after treatment (type D), 13 patients had the same height after treatment (type S), and 10 patients had a progressive increase in height (type I). Life table comparison showed no correlation between survival and location of tumour, sex of patient, size of tumour when treated, or laterality. There was a slight correlation between age and survival. Patients older than 60 died more frequently from metastatic melanoma than those under 60 (p = 0.06). Life table analysis showed a significant correlation between tumour regression type and survival. At 48 months the best cumulative probability of survival was in patients with type D (88% alive) compared with those of type I (34% alive, p = 0.0004). PMID:2378844

Abramson, D H; Servodidio, C A; McCormick, B; Fass, D; Zang, E

1990-01-01

21

Microdialysis documents changes in the micromilieu of psoriatic plaques under continuous systemic therapy.  

PubMed

Microdialysis is a novel technique suitable to analyse soluble mediators in the skin compartment. We applied this methodical approach to monitor changes in the micromilieu of psoriatic plaques under therapy. Tissue fluid was collected from lesional and non-lesional skin of three patients with severe plaque-type psoriasis prior to as well as after 12?weeks of continuous oral therapy with fumaric acid esters. Concentrations of a spectrum of cytokines and adipokines were measured using a commercial fluorescent bead immunoassay. The procedure was well tolerated even without local anaesthesia. Prior to initiation of therapy, we found elevated levels for IL-2, IL-6, IL-18, IL-23, and resistin in lesional versus non-lesional skin, whereas adiponectin levels were higher in non-lesional skin. All patients showed significant clinical improvement under treatment, paralleled by reduced concentrations of IL-6, IL-18, IL-23, and resistin, but not IL-2 and adiponectin in lesional skin. Thus, we were able to demonstrate through microdialysis a shift in the micromilieu of psoriatic plaques, characterized by reduced levels of pro-inflammatory mediators in three patients under effective systemic anti-inflammatory therapy with fumaric acid esters. Our observations need to be confirmed by larger studies. This approach is limited by practical aspects as it is very time-consuming, but suitable to directly explore pathomechanisms causing the psoriatic phenotype in general and insulin resistance in the skin compartment in particular. PMID:21255092

Salgo, Rebekka; Thaçi, Diamant; Boehncke, Sandra; Diehl, Sandra; Hofmann, Matthias; Boehncke, Wolf-Henning

2011-02-01

22

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

23

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

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

Radiation Therapy for Lung Cancer  

MedlinePLUS

... visit: National Cancer Institute www.cancer.gov/clinicaltrials Radiation Therapy Answers www.rtanswers.org STRO AMERICAN SOCIETY ... astro.org for more information. AMERICAN SOCIETY FOR RADIATION ONCOLOGY 8280 Willow Oaks Corporate Drive, Suite 500, ...

27

Radiation therapy of glioblastoma.  

PubMed

Glioblastoma multiforme (GBM) is the most common malignant brain tumor that affects approximately 17,000 patients annually. Clear survival advantages have been demonstrated with postoperative radiation therapy (RT) to doses of 5,000-6,000 cGy but dose-escalation attempts beyond 6,000 cGy have resulted in increased toxicity but no additional survival benefit. To improve local control and limit toxicity to normal brain tissue with these infiltrating tumors, novel imaging techniques are actively being explored to better define tumor extent and associated RT treatment fields. Hyperfractionated RT has been associated with a survival detriment. Current standard-of-care treatment involves concurrent use of temozolomide and RT to 6,000 cGy over 30 days followed by adjuvant temozolomide treatment for 6 months. Brachytherapy and stereotactic radiosurgery are effective therapies for relapsed GBM but tend to be associated with notable toxicity. More recently, re-irradiation strategies employ concurrent use of bevacizumab to limit treatment-related injury while still permitting delivery of meaningful doses. These clinical trials are ongoing and merits of these strategies are not yet clear but appear promising. PMID:25468225

Barani, Igor J; Larson, David A

2015-01-01

28

Radiation Therapy for Gynecologic Cancers  

MedlinePLUS

... is a doctor who specializes in surgically removing gynecologic cancers. While radiation therapy is eff ective enough to eliminate the need for surgery in some diseases, such as many cervical cancers, surgical removal of the tumor is often still an ...

29

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

PubMed

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

Allaker, Robert P; Douglas, C W Ian

2009-01-01

30

Radiation Therapy: Preventing and Managing Side Effects  

MedlinePLUS

... radiation therapy Preventing and managing side effects of radiation therapy When the radiation damages nearby healthy tissue, ... to reduce side effects is by using radioprotective ( ray -dee-o pro- TEK -tiv) drugs. These are ...

31

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

32

Method for microbeam radiation therapy  

DOEpatents

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

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

1994-08-16

33

RADIATION SAFETY CONSIDERATION DURING INTRAOPERATIVE RADIATION THERAPY.  

PubMed

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

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

2014-09-28

34

[Radiation therapy for malignant lymphoma].  

PubMed

Malignant lymphoma is usually radiosensitive and radiation therapy is an effective modality for local control of lymphoma. However, lymphoma is a typical systemic disease, and chemotherapy is performed for many cases. Recently, the late adverse events associated with radiotherapy (especially extended field radiation therapy), such as cardiovascular disease and secondary cancers, become a serious problem for long-term lymphoma survivors. In combination with chemotherapy, it is possible to reduce both the treatment volume and the overall treatment dose to minimise the risks of late adverse events. PMID:24724405

Asakawa, Isao; Tamamoto, Tetsuro; Hasegawa, Masatoshi

2014-03-01

35

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 ...

36

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

37

Radiation therapy for skin cancer  

SciTech Connect

Local control, cosmesis and functional results were evaluated in 315 cases of skin cancer in 247 patients treated with radiation therapy. The initial recurrence rate for basal cell carcinoma was 7.8% and for squamous cell carcinoma was 14.9%. Ultimate local control was achieved in 98.7% of the cases of basal cell carcinoma and in 94.0% of the cases of squamous cell carcinoma with use of further irradiation or other therapeutic modalities. Ultimate local control rates were comparable to other therapeutic modalities. Cosmetic and functional results were excellent. Cartilage necrosis was not a significant problem. Radiation therapy may offer advantages in certain clinical situations and should be considered as a mode of therapy in the treatment of skin cancer.

Fischbach, A.J.; Sause, W.T.; Plenk, H.P.

1980-11-01

38

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

39

Discipline of Radiation Therapy Trinity College Dublin  

E-print Network

Professor, followed by Patient 14.10-14.40: Radiation Therapy for Breast Cancer: Professional and Patient and public outreach event about radiation therapy treatment for cancer Venue: Science Gallery Trinity College Therapist, Zagreb, Croatia 17.00-17.30: Radiation Therapy for Prostate Cancer: Professional and Patient

O'Mahony, Donal E.

40

Radiation therapy of esophageal cancer  

SciTech Connect

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

Hancock, S.L.; Glatstein, E.

1984-06-01

41

En plaque intradural extramedullary spinal tuberculoma and concurrent intracranial tuberculomas: paradoxical response to antituberculous therapy. Case report.  

PubMed

Spinal intradural extramedullary tuberculoma is a rare entity. Rarer still are extensive en plaque intradural extramedullary tuberculomas occurring concurrently with multiple intracranial tuberculomas as a paradoxical response to chemotherapy for tuberculosis (TB). The authors describe the case of a 21-year-old man who was treated for tuberculous meningitis. Three months after the episode of meningitis, while undergoing chemotherapy for TB, he developed features of thoracic myelopathy. Investigations revealed an extensive en plaque intradural extramedullary lesion spanning seven segments in the lower thoracic spine. Magnetic resonance imaging of the brain revealed multiple asymptomatic intracranial tuberculomas. Even after further treatment with antituberculous chemotherapy was initiated, the lesion failed to respond. The authors performed a laminectomy and excised the en plaque intradural extramedullary lesion. The patient's condition responded well to this treatment. Although the appearance of intracranial tuberculoma as a paradoxical response to chemotherapy has been previously reported, no authors have reported on the development of an extensive en plaque intradural extramedullary tuberculoma in conjunction with asymptomatic multiple intracranial tuberculomas as a paradoxical response. In cases in which patients present with compressive myelopathy following therapy for tuberculous meningitis, it is important to consider in the differential diagnosis that intradural extramedullary tuberculoma may be a paradoxical response to chemotherapy. The authors' experience and their review of the literature indicate that surgery has a definitive role to play in the management of spinal intradural extramedullary tuberculoma. PMID:17330587

Muthukumar, Natarajan; Sureshkumar, Venkatachalam; Ramesh, Vengalathur Ganesan

2007-02-01

42

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

43

Multiple lentigines in areas of resolving psoriatic plaques after ustekinumab therapy.  

PubMed

The development of lentigines in areas previously involved by psoriasis has been reported in the literature, classically related to phototherapy but also to topical products. More recently, some authors have described several cases of lentigines appearing in resolving psoriatic plaques during or after treatment with anti-tumour necrosis factor (TNF) drugs used to treat severe plaque psoriasis, including adalimumab, etanercept, and infliximab. We report the case of a patient that developed multiple lentigines after clearance of the plaques of psoriasis receiving treatment with ustekinumab for his psoriasis. PMID:24746301

Guttierez-Gonzalez, E; Batalla, A; de la Mano, D

2014-01-01

44

Understanding Radiation Therapy: A Guide for Patients and Families  

MedlinePLUS

... Therapy + - Text Size Download Printable Version [PDF] » TOPICS Document Topics GO » SEE A LIST » What is radiation therapy? When is it used? How does radiation therapy work? Do the benefits of radiation therapy outweigh the ...

45

Intensity-Modulated Radiation Therapy (IMRT)  

MedlinePLUS

Intensity-Modulated Radiation Therapy (IMRT) • Overview Intensity-modulated radiation therapy (IMRT) is an advanced mode of high-precision radiotherapy that uses computer-controlled linear accelerators to deliver precise radiation doses to a malignant tumor or specific areas ...

46

Insufficiency fracture after radiation therapy  

PubMed Central

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

Oh, Dongryul

2014-01-01

47

Radiation Therapy and You: Support for People with Cancer  

MedlinePLUS

Español Radiation Therapy and You Radiation Therapy and You is for people who are about to receive or are ... ePub This booklet covers: Questions and Answers About Radiation Therapy. Answers common questions, such as what radiation ...

48

Radiation complications and tumor control after plaque radiotherapy of choroidal melanoma with macular involvement 1 1 Biostatistical consultation was provided by J. Cater, PhD  

Microsoft Academic Search

PURPOSE: To determine the outcome of plaque radiotherapy in the treatment of macular choroidal melanoma and to identify the risk factors associated with the development of radiation complications, tumor recurrence, and metastasis.METHODS: Chart analysis of 630 consecutive patients (630 eyes) with macular choroidal melanoma managed by plaque radiotherapy between July 1976 and June 1992.RESULTS: The median largest basal tumor diameter

Kaan Gündüz; Carol L Shields; Jerry A Shields; Jacqueline Cater; Jorge E Freire; Luther W Brady

1999-01-01

49

THE RADIATION THERAPY PLANNING PROBLEM CHRISTOPH BORGERS  

E-print Network

, but beams of electrons, protons, neutrons, and other particles are used as well. The planning be used. A radiation therapy plan speci es beam positions, directions, energies, etc., as well as whenTHE RADIATION THERAPY PLANNING PROBLEM CHRISTOPH BORGERS 1. Introduction. The purpose of this paper

Börgers, Christoph

50

Advanced Semiconductor Dosimetry in Radiation Therapy  

NASA Astrophysics Data System (ADS)

Modern radiation therapy is very conformal, resulting in a complexity of delivery that leads to many small radiation fields with steep dose gradients, increasing error probability. Quality assurance in delivery of such radiation fields is paramount and requires real time and high spatial resolution dosimetry. Semiconductor radiation detectors due to their small size, ability to operate in passive and active modes and easy real time multichannel readout satisfy many aspects of in vivo and in a phantom quality assurance in modern radiation therapy. Update on the recent developments and improvements in semiconductor radiation detectors and their application for quality assurance in radiation therapy, based mostly on the developments at the Centre for Medical Radiation Physics (CMRP), University of Wollongong, is presented.

Rosenfeld, Anatoly B.

2011-05-01

51

21 CFR 892.5300 - Medical neutron radiation therapy system.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Medical neutron radiation therapy system. 892.5300...Therapeutic Devices § 892.5300 Medical neutron radiation therapy system. (a) Identification. A medical neutron radiation therapy system is a...

2011-04-01

52

21 CFR 892.5300 - Medical neutron radiation therapy system.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Medical neutron radiation therapy system. 892.5300...Therapeutic Devices § 892.5300 Medical neutron radiation therapy system. (a) Identification. A medical neutron radiation therapy system is a...

2010-04-01

53

Plaque regression and plaque stabilisation in cardiovascular diseases  

PubMed Central

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

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

2013-01-01

54

Intraoperative radiation therapy following pancreaticoduodenectomy.  

PubMed Central

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

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

1993-01-01

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

Radiation Therapy for Testicular Cancer  

MedlinePLUS

... cancer Clinical trials for testicular cancer Complementary and alternative therapies for ... therapy for testicular cancer This treatment uses high-energy rays to kill cancer cells or slow their ...

57

Emergence of stereotactic body radiation therapy.  

PubMed

Stereotactic body radiation therapy (SBRT) evolved from the application of stereotactic radiosurgery, which is focused intracranial radiation. SBRT offers high doses of specific radiation with oligofractions (five or less) to a specified target, providing local control to circumscribed tumors while sparing surrounding normal tissue. Commonly treated cancers include tumors of the lung and liver. The challenge with SBRT is to account for organ motion and the achievement of precise targeting. SBRT uses three-dimensional radiation therapy planning, intensity-modulated radiation therapy, as well as image-guided organ motion and gating. SBRT is based on the premise of geometric avoidance, targeting the tumor with the goal of complete avoidance of the surrounding normal tissues and critical organs. An SBRT course of treatment ranges from one to five treatments (hypofractionated) and, therefore, differs from conventional radiation, which is usually a prolonged course ranging from two to six weeks of daily treatment. PMID:25542328

Behrend, Susan Weiss

2015-01-01

58

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

59

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

Code of Federal Regulations, 2013 CFR

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

2013-10-01

60

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

61

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

Code of Federal Regulations, 2010 CFR

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

2010-10-01

62

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

Code of Federal Regulations, 2014 CFR

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

2014-10-01

63

Systemic therapy of plaque-type psoriasis ameliorates endothelial cell function: results of a prospective longitudinal pilot trial.  

PubMed

Severe psoriasis is associated with significant cardiovascular mortality. We therefore investigated the effects of systemic therapy on the cardiovascular risk of psoriasis patients. Thirteen consecutive patients receiving fumaric acid esters were included and followed for 24 weeks both clinically and by means of laboratory monitoring, 10 completed the study. Eight of ten patients showed a PASI-50 response. Two of three patients with clinical insulin resistance (Homeostasis Model Assessment of insulin resistance >2.5) showed normal insulin responsiveness at the end of the study. Clinical improvement was paralleled by a reduction of high-sensitive CRP serum levels (median -25%). There was a trend toward reduced serum levels for the vascular endothelial growth factor (median -10%) and resistin (median -4%), while the potentially cardio-protective adiponectin showed a trend toward increased serum levels under therapy (median +19%). Systemic endothelial function assessed by venous occlusion plethysmography revealed an improvement of endothelial vasodilator function after 24 weeks of treatment (p < 0.02). This is the first prospective study documenting an amelioration of endothelial cell function in patients with moderate-to-severe plaque-type psoriasis under effective continuous systemic therapy. Future studies need to compare the cardioprotective effects of different treatment modalities, based on hard end points such as the rate of myocardial infarction. PMID:21170539

Boehncke, Sandra; Fichtlscherer, Stephan; Salgo, Rebekka; Garbaraviciene, Jurate; Beschmann, Heike; Diehl, Sandra; Hardt, Katja; Thaçi, Diamant; Boehncke, Wolf-Henning

2011-08-01

64

Comparing Postoperative Radiation Therapies for Brain Metastases  

Cancer.gov

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

65

Palliative radiation therapy for primary gastric melanoma  

PubMed Central

Introduction Primary gastric melanoma is an exceedingly rare cause of upper gastrointestinal bleeding (GI bleeding). Prior reports of primary gastric melanoma have mostly been treated with surgery with utilization of radiation therapy being unreported. Radiation therapy has been used to palliate bleeding of other cancers including lung, bladder, cervix, and more recently primary gastric cancers. Case presentation This case documents an 87-year-old male who presented with fatigue and melena, and was found to have severe anemia. Endoscopy with biopsy revealed an isolated focus of melanoma. After discharge, he presented two days later and was found to have continued bleeding. Because he was deemed a poor surgical candidate he elected to undergo palliative radiation therapy for bleeding control. Discussion The diagnosis of primary verses metastatic melanoma is a topic of debate. Case reports of patients with no known extra-gastric primary have undergone surgical treatment with varying outcomes. Patients with metastatic gastric melanoma have relied on chemotherapy and radiation in addition to surgery, with radiation being used in the palliative setting. The use of radiation to control bleeding in other cancers including primary gastric adenocarcinoma has been previously studied. This case documents the utilization of radiation therapy in bleeding due to primary gastric melanoma. Conclusions Radiation therapy can provide adequate bleeding palliation in patients with primary gastric melanoma. PMID:24490048

Slater, Jason M.; Ling, Ted C.; Slater, Jerry D.

2014-01-01

66

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

67

Nursing care update: Internal radiation therapy  

SciTech Connect

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

Lowdermilk, D.L.

1990-01-01

68

Particle Radiation Therapy: Requiem or Reveille  

PubMed Central

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

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

1979-01-01

69

Vulnerable Plaque  

MedlinePLUS

... plaque is formed in the following way. Fat droplets are absorbed by the artery, which causes the ... called macrophages and begin to soak up fat droplets. The fat-filled cells form a plaque with ...

70

Plaque Psoriasis  

MedlinePLUS

... Cycle Team NPF DIY Medical Professionals Donate Donate Psoriasis About Psoriasis Symptoms and Diagnosis Types of Psoriasis ... Kit Find Us Online YouTube Twitter Facebook Plaque Psoriasis Plaque psoriasis is the most common form of ...

71

OPTIMIZING THE SCENARIO POSITIONS FOR ROBUST RADIATION THERAPY TREATMENT PLANNING  

E-print Network

Royal Institute of Technology October 10, 2012 Abstract Complex external beam radiation therapy and proton therapy. It does so by optimizing the scenario positions along predefined directions scenario positions. 1. Introduction In external beam radiation therapy, misalignment of the patient

Forsgren, Anders

72

Care of the patient receiving radiation therapy  

SciTech Connect

External radiation therapy, or teletherapy, is the use of ionizing radiation to destroy cancer cells. Clinical use of ionizing radiation as treatment for cancer began with the discovery of x-rays in 1895, the identification of natural radioactivity (radium) in 1896, and the first reported cure of cancer, a basal cell epithelioma, induced by radiation in 1899. Initially, radiation was administered as a single large dose and produced severe, life-threatening side effects. The basis for the use of ionizing radiation in daily increments for a period of weeks was provided by Regaud in 1922; ten years later, Coutard clinically developed the method of dose fractionation, which remains in use today. Although the use of ionizing radiation as a treatment is over eighty years old, only in recent years have advancements in its clinical application been based on research related to the biologic effect of radiation on human cells. To effectively care for the patient prior to, during, and at the completion of external radiation therapy, the nurse must know the physical and biologic basis of external radiation therapy and its clinical application.

Yasko, J.M.

1982-12-01

73

The ASTEROID trial: coronary plaque regression with high-dose statin therapy.  

PubMed

A Study To Evaluate the effect of Rosuvastatin On Intravascular ultrasound-Derived coronary atheroma burden (ASTEROID) investigated the impact of high-dose rosuvastatin therapy on the rate of atheroma progression in patients with coronary artery disease. Serial intravascular ultrasound (IVUS) was performed in 349 patients at baseline and following 24 months of therapy with rosuvastatin 40 mg/day. Rosuvastatin therapy lowered low-density lipoprotein cholesterol to 60.8 mg/dl and raised high-density lipoprotein cholesterol by 14.7%. This was associated with a significant reduction in all IVUS measures of atheroma burden. These results suggest that intensive modification of lipid levels with high-dose statin therapy can promote atheroma regression. Further studies will be required to determine whether this benefit is associated with a reduction in clinical events. PMID:19804256

Chhatriwalla, Adnan K; Nicholls, Stephen J; Nissen, Steven E

2006-11-01

74

Impaired skin integrity related to radiation therapy  

SciTech Connect

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

Ratliff, C.

1990-09-01

75

Non-invasive in Vivo Characterization of Human Carotid Plaques with Acoustic Radiation Force Impulse Ultrasound: Comparison with Histology after Endarterectomy.  

PubMed

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

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

2015-03-01

76

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

77

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

78

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

79

Respiratory Motion Prediction in Radiation Therapy  

NASA Astrophysics Data System (ADS)

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

Vedam, Sastry

80

Postoperative Radiation Therapy for Parotid Mucoepidermoid Carcinoma  

PubMed Central

Salivary gland cancers are rare and represent approximately 5% of all head and neck cancers and only 0.3% of all malignancies. The majority (75%) of salivary gland tumors occur in the parotid gland, and while benign lesions are more common, mucoepidermoid carcinoma (MEC) makes up 40–50% of malignant parotid gland tumors. No randomized controlled trials exist regarding the role of adjuvant radiation for patients who undergo surgical resection of low-grade MECs. Herein, we report two cases of successful postoperative radiation therapy in low-grade, pT2N0 MEC of the parotid gland. The role of adjuvant radiation therapy for patients with MEC of the parotid gland is based on data from institution reviews and lacks data from randomized controlled trials. Per our review of the literature, the pathological findings of positive surgical margins and/or perineural invasion in two patients with low-grade MEC of the parotid gland warranted adjuvant radiation for improved local control after partial parotidectomy. Both patients tolerated postoperative radiation therapy with only mild side effects and, at last follow-up, five years after completion of therapy, had no clinical or radiographic evidence of either local recurrence or distant metastasis. PMID:25580323

Olsen, Meghan P.; Mitchell, Allen O.; Miles, Edward F.

2014-01-01

81

Radioprotective agents for radiation therapy: future trends.  

PubMed

ABSTRACT? Only two radioprotective compounds, amifostine and palifermin, currently have the US FDA approval for use in radiation therapy. However, several agents have been reported that show therapeutic promise. Many of these agents are free radical scavengers/antioxidants. Superoxide dismutase and superoxide dismutase mimetics, nitroxides and dietary antioxidants are all being investigated. Recently, alternative strategies of drug development have been evolving, which focus on targeting the series of cellular insult recognition/repair responses initiated following radiation. These agents, which include cytokines/growth factors, angiotensin-converting enzyme inhibitors and apoptotic modulators, show promise of having significant impact on the mitigation of radiation injury. Herein, we review current literature on the development of radioprotectors with emphasis on compounds with proven or potential usefulness in radiation therapy. PMID:25525844

Johnke, Roberta M; Sattler, Jennifer A; Allison, Ron R

2014-12-01

82

Bullous pemphigoid after radiation therapy  

SciTech Connect

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

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

1988-02-01

83

Wound Care After Radiation Therapy  

Microsoft Academic Search

More than 50% of all cancer patients receive some form of radiotherapy for tumor control preoperatively, postoperatively, or as sole treatment. Radiation-induced wounds are a concern for patients and practitioners. Current research investigating alternative treatment strategies offers the hope of improved wound healing and enhanced quality of life for patients with these wounds. This paper reviews the pathophysiology of wounds

Felicia A. Mendelsohn; Celia M. Divino; Ernane D. Reis; Morris D. Kerstein

2002-01-01

84

Heavy-ion sources for radiation therapy  

Microsoft Academic Search

The usefulness of particle beams for radiation therapy has been well and widely recognized. For the cure of cancer patients, many accelerator facilities have already been utilized, and some new facilities are now being put into operation, or are under construction. Considering the medical and biological requirements, light heavy ions with an energy of several hundred MeV\\/nucleon are regarded as

Y. Sato; A. Kitagawa; H. Ogawa; S. Yamada

1994-01-01

85

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).

86

Radiation Therapy for Colon, Rectum and Anus Cancers  

MedlinePLUS

... Treating Colon, Rectum and Anus Cancers External Beam Radiation Therapy Possible Side Effects Caring for Yourself During Treatment ... with these types of cancer often benefit from radiation therapy as part of treatment. Some cancers involving the ...

87

BIOLOGY CONTRIBUTION PREFERENTIAL EFFECT OF SYNCHROTRON MICROBEAM RADIATION THERAPY  

E-print Network

BIOLOGY CONTRIBUTION PREFERENTIAL EFFECT OF SYNCHROTRON MICROBEAM RADIATION THERAPY: Synchrotron microbeam radiation therapy (MRT) relies on spatial fractionation of the incident photon beam- provement of such differential effects on the vasculature. Ã? 2010 Elsevier Inc. Synchrotron Microbeam

88

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

89

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 required for calculating dose plans. Radiation therapy based only on MRI would be advantageous in manyMRI in Radiation Therapy Planning: The Use of Ultrashort Echo Time Imaging Hans Martin Kjer Kongens

90

Pulsed laser radiation therapy of skin tumors  

SciTech Connect

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

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

1980-11-15

91

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

92

Radiation therapy with fast neutrons: A review  

NASA Astrophysics Data System (ADS)

Because of their biological effects fast neutrons are most effective in treating large, slow-growing tumours which are resistant to conventional X-radiation. Patients are treated typically 3-4 times per week for 4-5 weeks (sometimes in combination with X-radiation) for a variety of conditions such as carcinomas of the head and neck, salivary gland, paranasal sinus and breast; soft tissue, bone and uterine sarcomas and malignant melanomas. It is estimated that about 27,000 patients have undergone fast neutron therapy to date.

Jones, D. T. L.; Wambersie, A.

2007-09-01

93

Image-guided radiation therapy: Physician's perspectives.  

PubMed

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

2012-10-01

94

Intraoperative radiation therapy in recurrent ovarian cancer  

SciTech Connect

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

Yap, O.W. Stephanie [Division of Gynecologic Oncology, Department of Gynecology and Obstetrics, Stanford University School of Medicine, Stanford, CA (United States)]. E-mail: stbeast@stanford.edu; Kapp, Daniel S. [Division of Radiation Therapy, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); Teng, Nelson N.H. [Division of Gynecologic Oncology, Department of Gynecology and Obstetrics, Stanford University School of Medicine, Stanford, CA (United States); Husain, Amreen [Division of Gynecologic Oncology, Department of Gynecology and Obstetrics, Stanford University School of Medicine, Stanford, CA (United States)

2005-11-15

95

Particle Radiation Therapy for Gastrointestinal Malignancies  

PubMed Central

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

Meyer, Jeffrey J.; Willett, Christopher G.

2007-01-01

96

Recent Advances in Radiation Therapy for Head and Neck Cancer  

Microsoft Academic Search

The treatment of locally advanced or recurrent head and neck cancers has improved from single modality interventions of surgery and radiation therapy alone to include combined modality therapy with surgery, chemotherapy and radiation. Combined therapy has led to improved local control and disease-free survival. New developments in radiation oncology such as altered fractionation, three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, stereotactic radiosurgery,

Madan Bangalore; Shirnett Matthews; Mohan Suntharalingam

2007-01-01

97

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

98

Collimator design for experimental minibeam radiation therapy  

SciTech Connect

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

Babcock, Kerry; Sidhu, Narinder; Kundapur, Vijayananda; Ali, Kaiser [Saskatoon Cancer Centre, 20 Campus Drive, Saskatoon, Saskatchewan S7N 4H4 (Canada)

2011-04-15

99

Microwave plaque thermoradiotherapy for choroidal melanoma.  

PubMed Central

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

Finger, P. T.

1992-01-01

100

Live\\/dead real-time polymerase chain reaction to assess new therapies against dental plaque-related pathologies  

Microsoft Academic Search

DNA-based methodology for the identification and detection of specific bacteria in dental plaque offers advantages over culturing techniques. One drawback of current molecular techniques like real-time quantitative polymerase chain reaction (RT-QPCR) is that they are not able to distinguish between live or dead bacteria. To overcome this problem an assay was assessed to discriminate between viable or dead bacteria using

G. Loozen; N. Boon; M. Pauwels; M. Quirynen; W. Teughels

2011-01-01

101

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

102

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

PubMed

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

2013-01-01

103

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

104

Proton Beam Radiation Therapy for Head and Neck Malignancies  

Microsoft Academic Search

Proton beam radiation therapy (PBRT) has unique physical properties (e.g., Bragg Peak) that limit the amount of normal tissue\\u000a irradiated in the head and neck region while maximizing the radiation delivered to the tumor. Radiation therapy is commonly\\u000a used in both the primary and adjuvant setting for many head and neck malignancies. Limiting the unnecessary radiation to normal\\u000a tissues within

Steven J. Frank; Ugur Selek

2010-01-01

105

[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

106

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

107

Future Particle Accelerator Developments for Radiation Therapy  

NASA Astrophysics Data System (ADS)

During the last decade particle beam cancer therapy has seen a rapid increase in interest, and several new centers have been built, are currently under construction, or are in an advanced stage of planning. Typical treatment centers today consist of an accelerator capable of producing proton or ion beams in an energy range of interest for medical treatment, i.e. providing a penetration depth in water of about 30 cm, a beam delivery system to transport the produced beam to the patient treatment rooms, and several patient stations, allowing for an optimal usage of the continuously produced beam. This makes these centers rather large and consequently expensive. Only major hospital centers situated in an area where they can draw on a population of several million can afford such an installation. In order to spread the use of particle beam cancer therapy to a broader population base it will be necessary to scale down the facility size and cost. This can in principle be done by reducing the number of treatment rooms to one, eliminating the need of an elaborate beam delivery system, and thereby reducing the building size and cost. Such a change should be going in parallel with a reduction of the accelerator itself, and a number of approaches to this are currently being pursued. If successful, such developments could eventually lead to a compact system where all components would fit into a single shielded room, not much different in size from a typical radiation vault for radiotherapy with X-rays.

Holzscheiter, Michael H.; Bassler, Niels

108

Proton-beam radiation therapy dosimetry standardization  

SciTech Connect

Beams of protons have been used for radiation therapy applications for over 40 years. In the last decade the number of facilities treating patients and the total number of patients being treated has begun go grow rapidly. Due to the limited and experimental nature of the early programs, dosimetry protocols tended to be locally defined. With the publication of the AAPM Task Group 20 report {open_quotes}Protocol for Dosimetry of Heavy Charged Particles{close_quotes} and the {open_quotes}European Code of Practice for Proton-Beam Dosimetry{close_quotes} the practice of determining dose in proton-beam therapy was somewhat unified. The ICRU has also recently commissioned a report on recommendations for proton-beam dosimetry. There have been three main methods of determining proton dose; the Faraday cup technique, the ionization chamber technique, and the calorimeter technique. For practical reasons the ionization chamber technique has become the most widely used. However, due to large errors in basic parameters (e.g., W-value) is also has a large uncertainty for absolute dose. It has been proposed that the development of water calorimeter absorbed dose standards would reduce the uncertainty in absolute proton dose as well as the relative dose between megavoltage X-ray beams and proton beams. The advantages and disadvantages are discussed.

Gall, K.P.

1995-12-31

109

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

Code of Federal Regulations, 2014 CFR

...Nuclear Medicine Technologists, and Radiation Therapy Technologists F Appendix...Nuclear Medicine Technologists, and Radiation Therapy Technologists The following...Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2....

2014-10-01

110

Ultraviolet radiation therapy and UVR dose models.  

PubMed

Ultraviolet radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to ultraviolet (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative ultraviolet dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for ultraviolet phototherapy are also examined, and the need for an accurate computational dose estimation method in ultraviolet phototherapy is discussed. PMID:25563284

Grimes, David Robert

2015-01-01

111

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

112

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, Switzerland Key words: 9L gliosarcoma, advanced brain tumor, gene-mediated immunoprophylaxis, microbeam radiation therapy, rats Summary Purpose: Microbeam radiation therapy (MRT), a novel experimental

Terasaki, Mark

113

Prospective evaluation of formalin therapy for radiation proctitis  

Microsoft Academic Search

BACKGROUND: Radiation proctitis is a troublesome complication of radiation therapy for as many as 75% of patients after pelvic irradiation. Five percent progress to chronic radiation proctitis complicated by telangiectasias and hemorrhage. The utility of formalin rectal instillation for treatment of bleeding is prospectively evaluated in this study.METHODS:Eleven patients (9 male, 2 female) with rectal bleeding after pelvic irradiation were

Steven F Counter; Daniel P Froese; Michael J Hart

1999-01-01

114

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. PMID:25276313

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

2014-01-01

115

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

116

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

117

Managing Radiation Therapy Side Effects: What to Do about Hair Loss (Alopecia)  

MedlinePLUS

... out 2 to 3 weeks after your first radiation therapy session. If you are getting radiation to the ... gov/livehelp NCI has a series of 9 Radiation Therapy Side Effects Sheets at: www.cancer.gov/radiation- ...

118

Radiation Therapy for Soft Tissue Sarcomas  

MedlinePLUS

... Chemotherapy for soft tissue sarcomas Targeted therapy for soft tissue sarcoma Clinical trials for soft tissue sarcomas Complementary and ... been proven to be a better treatment for soft tissue sarcoma. Proton beam therapy is not widely available. Another ...

119

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

120

Radiation Therapy -- What It Is, How It Helps  

MedlinePLUS

... ACS » Radiation Therapy -- What It Is, How It Helps Download Printable Version [PDF] » This easy-to-read ... Health Finish the Fight Press Room Mobile Site Help Site Map Privacy Accessibility Terms of Use State ...

121

21 CFR 892.5750 - Radionuclide radiation therapy system.  

Code of Federal Regulations, 2012 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification....

2012-04-01

122

21 CFR 892.5750 - Radionuclide radiation therapy system.  

Code of Federal Regulations, 2013 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification....

2013-04-01

123

21 CFR 892.5300 - Medical neutron radiation therapy system.  

Code of Federal Regulations, 2014 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5300 Medical neutron radiation therapy system. (a)...

2014-04-01

124

21 CFR 892.5750 - Radionuclide radiation therapy system.  

Code of Federal Regulations, 2011 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification....

2011-04-01

125

21 CFR 892.5750 - Radionuclide radiation therapy system.  

Code of Federal Regulations, 2014 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification....

2014-04-01

126

21 CFR 892.5300 - Medical neutron radiation therapy system.  

Code of Federal Regulations, 2012 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5300 Medical neutron radiation therapy system. (a)...

2012-04-01

127

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2012 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification....

2012-04-01

128

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2011 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification....

2011-04-01

129

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2013 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification....

2013-04-01

130

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2014 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification....

2014-04-01

131

21 CFR 892.5750 - Radionuclide radiation therapy system.  

Code of Federal Regulations, 2010 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification....

2010-04-01

132

21 CFR 892.5300 - Medical neutron radiation therapy system.  

Code of Federal Regulations, 2013 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5300 Medical neutron radiation therapy system. (a)...

2013-04-01

133

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2010 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification....

2010-04-01

134

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

135

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

136

Microdosimetry and radiation quality determinations in radiation protection and radiation therapy.  

PubMed

Beams of different radiation qualities may, for equal absorbed dose, lead to important differences in the degree of harm for a specific biological endpoint. In many practical situations absorbed dose is then not a sufficient measure when for instance the same treatment result or risk level is the focus of attention. In radiation protection, the absorbed dose may be different by a factor of 20 between the most and least effective radiation qualities. In radiation therapy the corresponding factor is approximately 3. Two physical quantities related to the charged particle track structure, LET, and lineal energy, y, are used to characterise radiation quality. Their values are dependent on whether focus is on targets in the micrometer range (chromosomes, cell nucleus, etc.) or in the nanometre range (DNA structures). The two quantities, LET, and y, have important differences, which emphasise different characteristics of a track. Applications will be discussed. PMID:21227959

Lindborg, L; Nikjoo, H

2011-02-01

137

Combination of Gene Therapy with Radiation  

Microsoft Academic Search

To date tremendous progress has been made in the field of cancer gene therapy. Strategies have been explored for achieving\\u000a therapeutic benefit using various genes and several clinical trials for cancer gene therapy have been carried out demonstrating\\u000a that gene therapy is well tolerated. However, in most cases the efficacy of gene transfer has been very limited. As an alternative,

Anupama Munshi; Raymond E. Meyn

138

Combination hyperthermia and radiation therapy for malignant melanoma  

SciTech Connect

Since 1975, clinical studies have been carried out to determine whether radiation when combined with localized hyperthermia evokes improved tumor control compared to that achieved with radiation alone. Local tumor hyperthermia was achieved using radiofrequency inductive heating at 27.12 MHz. In bulky lesions (>100 cm/sup 3/), radiofrequency conductive heating at 13.56 MHz was also used. More than 100 lesions in 38 patients were treated with radiation alone and hyperthermia in combination with radiation. Most lesions were treated either twice a week or once a week, depending on radiation dose fractionation scheme used. The overall result of tumor control rate of the combined therapy is superior to radiation therapy alone (75% versus 46%; P < 0.01). No enhanced normal tissue morbidity was seen following the combined therapy. The detailed analysis of the treatment results shows that the tumor control rate is dependent on dose per fraction, the total dose, and the initial tumor volume. The radiation alone, at high doses per fraction, was effective in controlling 80% of the lesions, if the tumor volume was less than 10 cm/sup 3/, compared to 30% when the tumor volumes were larger. The combination therapy, on the other hand effected 80% local tumor control regardless of the tumor volume. The importance of good thermal distribution within the tumor volume, selective heating of the tumor tissues and the sequence and time interval between the combined therapy is discussed.

Kim, J.H. (Memorial Sloan-Kettering Cancer Center, New York); Hahn, E.W.; Ahmed, S.A.

1982-08-01

139

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

140

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

SciTech Connect

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

Gay, Hiram A., E-mail: hgay@radonc.wustl.edu [Washington University School of Medicine, St Louis, MO (United States); Barthold, H. Joseph [Commonwealth Hematology and Oncology, Weymouth, MA (United States); Beth Israel Deaconess Medical Center, Boston, MA (Israel); O'Meara, Elizabeth [Radiation Therapy Oncology Group, Philadelphia, PA (United States); Bosch, Walter R. [Washington University School of Medicine, St Louis, MO (United States); El Naqa, Issam [Department of Radiation Oncology, McGill University Health Center, Montreal, Quebec (Canada); Al-Lozi, Rawan [Washington University School of Medicine, St Louis, MO (United States); Rosenthal, Seth A. [Radiation Oncology Centers, Radiological Associates of Sacramento, Sacramento, CA (United States); Lawton, Colleen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Lee, W. Robert [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Sandler, Howard [Cedars-Sinai Medical Center, Los Angeles, CA (United States); Zietman, Anthony [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Myerson, Robert [Washington University School of Medicine, St Louis, MO (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Willett, Christopher [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Kachnic, Lisa A. [Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, MA (United States); Jhingran, Anuja [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Portelance, Lorraine [University of Miami, Miami, FL (United States); Ryu, Janice [Radiation Oncology Centers, Radiological Associates of Sacramento, Sacramento, CA (United States); and others

2012-07-01

141

Live/dead real-time polymerase chain reaction to assess new therapies against dental plaque-related pathologies.  

PubMed

DNA-based methodology for the identification and detection of specific bacteria in dental plaque offers advantages over culturing techniques. One drawback of current molecular techniques like real-time quantitative polymerase chain reaction (RT-QPCR) is that they are not able to distinguish between live or dead bacteria. To overcome this problem an assay was assessed to discriminate between viable or dead bacteria using DNA intercalating substances, propidium monoazide (PMA) and ethidium monoazide (EMA) in combination with RT-QPCR. The assay was tested on oral pathogens: Streptococcus mutans, Prevotella intermedia and Aggregatibacter actinomycetemcomitans. To determine the effectiveness of EMA and PMA, different concentrations (from 5 to 100 ?g ml(-1)) of the substances were added to viable or heat-killed suspensions of both organisms (ranging from 10(8) to 10(4) colony-forming units ml(-1)). Afterwards, PMA was tested on mixtures of varying ratios of viable and dead cells. After DNA extraction, RT-QPCR was performed using species-specific primers. Both compounds inhibited PCR amplification from dead cells. The EMA treatment resulted in the largest signal decrease but EMA also inhibited DNA amplification from viable cells. For this reason, PMA was selected for use in further experiments. It was shown to be efficient in allowing selective PCR detection of only viable cells in mixtures containing both viable and dead cells. The amount of amplified DNA corresponded to the percentage of viable cells in the sample. The developed assay will potentially be useful for assessing bacterial loads remaining after disinfection protocols without interference by non-viable bacteria. PMID:21729246

Loozen, G; Boon, N; Pauwels, M; Quirynen, M; Teughels, W

2011-08-01

142

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

143

Intensity-Modulated Radiation Therapy for Head and Neck Carcinoma  

Microsoft Academic Search

Intensity-modulated radiation therapy (IMRT) for head and neck tumors refers to a new approach that aims at increasing the radiation dose gradient between the target tissues and the surrounding normal tissues at risk, thus offering the prospect of increasing the locore- gional control probability while decreasing the compli- cation rate. As a prerequisite, IMRT requires a proper selection and delineation

VINCENT GRÉGOIRE; WILFRIED DE NEVE; AVRAHAM EISBRUCH; NANCY LEE; DANIELLE VAN DEN WEYNGAERT

2007-01-01

144

Argon plasma coagulation therapy for hemorrhagic radiation proctosigmoiditis  

Microsoft Academic Search

Background: Radiation-induced proctosigmoiditis is a serious complication of pelvic radiation therapy. Rectal bleeding occurs among 6% to 8% of these patients and is extremely difficult to manage. Pharmacotherapy is generally ineffective, whereas surgical treatment is associated with high morbidity and mortality. Argon plasma coagulation is a new method of noncontact electrocoagulation well suited for hemostasis of large bleeding areas. Methods:

Rui A. Silva; António J. Correia; Luís Moreira Dias; Helena Lomba Viana; Rafael Lomba Viana

1999-01-01

145

Stereotactic body radiation therapy: a novel treatment modality  

Microsoft Academic Search

Stereotactic body radiation therapy (SBRT) involves the delivery of a small number of ultra-high doses of radiation to a target volume using very advanced technology and has emerged as a novel treatment modality for cancer. The role of SBRT is most important at two cancer stages—in early primary cancer and in oligometastatic disease. This modality has been used in the

Achilles J. Fakiris; Eric L. Chang; Nina A. Mayr; Jian Z. Wang; Lech Papiez; Bin S. Teh; Ronald C. McGarry; Higinia R. Cardenes; Robert D. Timmerman; Simon S. Lo

2009-01-01

146

Radiation Therapy for Neovascular Age-related Macular Degeneration  

SciTech Connect

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

Kishan, Amar U. [Harvard Medical School, Boston, Massachusetts (United States)] [Harvard Medical School, Boston, Massachusetts (United States); Modjtahedi, Bobeck S.; Morse, Lawrence S. [Department of Ophthalmology and Vision Sciences, University of California, Davis, Sacramento, California (United States)] [Department of Ophthalmology and Vision Sciences, University of California, Davis, Sacramento, California (United States); Lee, Percy, E-mail: percylee@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California (United States)] [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California (United States)

2013-03-01

147

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

148

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

PubMed Central

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 V10 and mean lung dose (MLD) of the previous plan and the V10-V40 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), V20 ?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 V20 ?30% on composite (previous RT + SABR) plans. Prospective studies are needed to validate these predictors and the scoring system on which they are based. PMID:22543216

Liu, Hui; Zhang, Xu; Vinogradskiy, Yevgeniy Y.; Swisher, Stephen G.; Komaki, Ritsuko; Chang, Joe Y.

2013-01-01

149

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

150

Applications of laser-accelerated particle beams for radiation therapy  

NASA Astrophysics Data System (ADS)

Proton beams are more advantageous than high-energy photons and electrons for radiation therapy because of their finite penetrating range and the Bragg peak near the end of their range, which have been utilized to achieve better dose conformity to the treatment target allowing for dose escalation and/or hypofractionation to increase local tumor control, reduce normal tissue complications and/or treatment time/cost. Proton therapy employing conventional particle acceleration techniques is expensive because of the large accelerators and treatment gantries that require excessive space and shielding. Compact proton acceleration systems are being sought to improve the cost-effectiveness for proton therapy. This paper reviews the physics principles of laser-proton acceleration and the development of prototype laserproton therapy systems as a solution for widespread applications of advanced proton therapy. The system design, the major components and the special delivery techniques for energy and intensity modulation are discussed in detail for laser-accelerated proton therapy.

Ma, C.-M.; Fourkal, E.; Li, J. S.; Veltchev, I.; Luo, W.; Fan, J. J.; Lin, T.; Tafo, A.

2011-05-01

151

Intensity-modulated radiation therapy for prostate cancer.  

PubMed

Prostate cancer is among the most common solid malignancies. A number of treatment alternatives exist for localized prostate cancer, including observation, prostatectomy, brachytherapy, and external-beam radiation therapy (EBRT). External-beam radiation therapy has changed dramatically during the past several years. Older techniques paved the way for 3-dimensional conformal radiation therapy (CRT), which in turn facilitated the introduction of intensity-modulated radiation therapy (IMRT). The prostate has served as a model disease site for the implementation of IMRT. As indicated by a growing body of experience, IMRT for prostate cancer represents a major technologic and clinical advance for radiation therapy. In this article, a review is provided of the evolution of EBRT leading to IMRT, the unique features making the prostate an ideal disease site for employing IMRT, the details of the clinical implementation of prostate IMRT and supporting technologic advancements, and the currently reported clinical outcomes of IMRT in prostate cancer. In addition, future directions of prostate IMRT, both technologic and clinical, are discussed. PMID:15040870

Jani, Ashesh B; Roeske, John C; Rash, Carla

2003-09-01

152

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

NASA Astrophysics Data System (ADS)

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

Pyakuryal, Anil

2009-03-01

153

Rationale for combining surgery and radiation therapy  

SciTech Connect

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

Suit, H.D.; Todoroki, T.

1985-05-01

154

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

155

Radiation therapy: neoadjuvant, adjuvant, or not at all.  

PubMed

Clinical trial data show that radiation enhances local tumor control of extremity sarcomas with acceptable morbidity when sophisticated radiation techniques are combined with limb-sparing resections performed by oncologic surgeons with sarcoma expertise. Similar controlled data is not available for retroperitoneal sarcomas but some studies suggest a benefit for radiotherapy. Radiation can be delivered by external beam or brachytherapy; it can be given pre-operatively, post-operatively, or intra-operatively. Indications for and advances in radiation therapy are discussed in this article. PMID:22365516

Delaney, Thomas F

2012-04-01

156

Considering the role of radiation therapy for gastrointestinal stromal tumor.  

PubMed

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

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

2014-01-01

157

Considering the role of radiation therapy for gastrointestinal stromal tumor  

PubMed Central

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

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

2014-01-01

158

Progress and controversies: Radiation therapy for prostate cancer.  

PubMed

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. PMID:25234700

Martin, Neil E; D'Amico, Anthony V

2014-01-01

159

Radiation beam therapy evolution: From X-rays to hadrons  

SciTech Connect

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

Khoroshkov, V. S. [Institute of Theoretical and Experimental Physics (Russian Federation)], E-mail: khoroshkov@itep.ru

2006-10-15

160

Management of Chemotherapeutic Agent Extravasation and Radiation Therapy Adverse Effects  

Microsoft Academic Search

\\u000a Although chemotherapy and radiation therapy are very effective modalities against cancer, both of these powerful therapies\\u000a can have significant adverse effects on oncology patients. Chemotherapeutic agents can extravasate from veins, damaging nearby\\u000a tissues, whereas therapeutic irradiation also can cause extensive tissue damage. Each member of the healthcare team should\\u000a recognize and help to prevent these complications among oncology patients. Furthermore,

Ida K. Fox; Howard N. Langstein

161

Diagnosis of delayed cerebral radiation necrosis following proton beam therapy  

Microsoft Academic Search

A 27-year-old man developed delayed cerebral radiation necrosis following proton beam therapy to an arteriovenous malformation. Neuroimaging with technetium 99m diethylenetriamine penta-acetic acid and positron emission tomographic scanning with fludeoxyglucose F 18 aided in his evaluation. Significant improvement of his neurologic deficits resulted from corticosteroid therapy. Clinical resolution was corroborated by serial computed tomographic scans demonstrating regression of the abnormality

M. Kaufman; B. E. Swartz; M. Mandelkern; J. Ropchan; M. Gee; W. H. Blahd

1990-01-01

162

The physical basis and future of radiation therapy  

PubMed Central

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

Bortfeld, T; Jeraj, R

2011-01-01

163

The physical basis and future of radiation therapy.  

PubMed

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

Bortfeld, T; Jeraj, R

2011-06-01

164

Complications following radiation therapy to the head  

SciTech Connect

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

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

1986-03-01

165

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

166

The thermoluminescence response of Ge-doped silica fibres for synchrotron microbeam radiation therapy dosimetry  

Microsoft Academic Search

In radiation cancer therapy, the aim is to destroy the tumour cells in the treated area while minimizing damage to the surrounding normal tissue. Synchrotron microbeam radiation therapy offers considerable promise in this respect, based on knowledge that normal tissue can tolerate high doses of radiation over small volumes. At the ESRF microbeam radiation therapy facility, one of the several

A. T. Abdul Rahman; D. A. Bradley; S. J. Doran; Brochard Thierry; Elke Bräuer-Krisch; A. Bravin

2010-01-01

167

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

168

Synchrotron Radiation Therapy from a Medical Physics point of view  

SciTech Connect

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

Prezado, Y.; Berkvens, P.; Braeuer-Krisch, E.; Renier, M.; Bravin, A. [ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz B.P. 220, 38043 Grenoble Cedex (France); Adam, J. F. [INSERM, U836, Equipe 6, BP 170, Grenoble Cedex 9, F-38042 (France); Universite Joseph Fourier, B.P. 51, Grenoble Cedex 9, F-38041 (France); ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz B.P. 220, 38043 Grenoble Cedex (France); Centre Hospitalier Universitaire, B.P. 217, Grenoble Cedex 9, F-38043 (France); Martinez-Rovira, I. [ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz B.P. 220, 38043 Grenoble Cedex (France); Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, E-08028 Barcelona (Spain); Fois, G. [ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz B.P. 220, 38043 Grenoble Cedex (France); Dipartimento di Fisica, Universita degli Studi di Cagliari, Strada Provinciale Monserrato Sestu km 0.700, Monserrato, Cagliari 09042 (Italy); Thengumpallil, S. [ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz B.P. 220, 38043 Grenoble Cedex (France); Dipartimento di Fisica E. Amaldi, Universita degli Studi Roma Tre, 84 Via della Vasca Navale, 00146 Roma (Italy); Edouard, M.; Deman, P. [INSERM, U836, Equipe 6, BP 170, Grenoble Cedex 9, F-38042 (France); Universite Joseph Fourier, B.P. 51, Grenoble Cedex 9, F-38041 (France); ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz B.P. 220, 38043 Grenoble Cedex (France); Vautrin, M. [INSERM, U836, Equipe 6, BP 170, Grenoble Cedex 9, F-38042 (France); Universite Joseph Fourier, B.P. 51, Grenoble Cedex 9, F-38041 (France); DOSIsoft, Cachan (France)

2010-07-23

169

Synchrotron Radiation Therapy from a Medical Physics point of view  

NASA Astrophysics Data System (ADS)

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

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

2010-07-01

170

Practical aspects of pediatric proton radiation therapy.  

PubMed

Many radiotherapy centers desire proton therapy (PrT) because the unique physical dosimetry allows for improved dose distribution in some clinical situations. These benefits are best described in skull base and many pediatric lesions. However, there are significant challenges to PrT that are overlooked or simply ignored when centers embark on the PrT journey particularly as it applies to pediatric patients.In this review, we review the Indiana University Health Proton Therapy Center experience regarding benefits and drawbacks of PrT for pediatric patients. In conclusion, centers aspiring to PrT capacity should be aware not only of the well-described benefits in some clinical scenarios, but also the significant challenges to the modality in its practical clinical application. PMID:25415684

McMullen, Kevin P; Kerstiens, John; Johnstone, Peter A S

2014-01-01

171

Antibody-targeted radiation cancer therapy  

Microsoft Academic Search

Several monoclonal antibodies are now approved for cancer therapy, such as rituximab, an anti-CD20 monoclonal antibody for the treatment of B-cell non-Hodgkin's lymphoma. Such 'naked' antibodies can recruit the body's immune effector mechanisms to kill cells expressing the target of the antibody. In recent years, the linking of radionuclides to antibodies to either augment inherent activity or to exploit the

Diane E. Milenic; Erik D. Brady; Martin W. Brechbiel

2004-01-01

172

Management of high-risk prostate cancer: radiation therapy and hormonal therapy.  

PubMed

The prognosis of high-risk prostate cancer is poor with a high mortality rate. The Radiation Therapy Oncology Group (RTOG) has performed dose-escalation studies of external beam radiation therapy (EBRT) and has developed high-precision radiation therapy (RT) methods such as intensity-modulated RT, carbon ion therapy, and proton beam therapy. High-dose rate brachytherapy (HDR-BT) is also studied as an option for high-risk prostate cancer treatment. Past clinical trials have suggested that the local control rate of high-risk prostate cancer improves with total EBRT dose, even for doses > 70 Gy. Several randomized controlled trials, including RTOG 94-06, have shown significantly better prognoses with higher doses (> 75 Gy) than with lower doses (< 70 Gy). A proton beam therapy trial (PROG 95-09) also showed similar results. A phase II clinical trial (National Institute for Radiological Sciences, Japan; trial 9904) showed that carbon ion therapy resulted in very good biochemical recurrence-free survival rates among high-risk prostate cancer patients, demonstrating particle therapy to be a valid treatment option. RTOG 86-10 showed that short-term neo-adjuvant hormonal therapy (HT) was inadequate for high-risk prostate cancer but effective for intermediate-risk prostate cancer, whereas RTOG 92-02 and the European Organisation for Research and Treatment of Cancer (EORTC) 22863 showed significant improvements in the prognosis of high-risk groups receiving long-term (> 2 years) HT combined with definitive RT. Further studies are warranted to elucidate optimal irradiation doses, HT treatment durations, and combination therapy schedules. PMID:23648323

Nomiya, Takuma; Tsuji, Hiroshi; Toyama, Shingo; Maruyama, Katsuya; Nemoto, Kenji; Tsujii, Hirohiko; Kamada, Tadashi

2013-12-01

173

Hypofractionated radiation therapy for prostate cancer: biologic and technical considerations  

PubMed Central

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

Sanfilippo, Nicholas J; Cooper, Benjamin T

2014-01-01

174

[Intensity-modulated radiation therapy and stereotactic body radiation therapy for head and neck tumors: evidence-based medicine].  

PubMed

Over the last decade, there have been many technical advances in radiation therapy, such as the spread of intensity-modulated conformal radiotherapy, and the rise of stereotactic body radiation therapy. By allowing better dose-to-target conformation and thus better organs at risk-sparing, these techniques seem very promising, particularly in the field of head and neck tumors. The present work aims at analyzing the level of evidence and recommendation supporting the use of high-technology radiotherapy in head and neck neoplasms, by reviewing the available literature. PMID:25155467

Lapierre, A; Martin, F; Lapeyre, M

2014-10-01

175

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

176

Radiation therapy of retroperitoneal soft tissue sarcomas  

Microsoft Academic Search

Between 1971 and 1982, 23 patients have been treated with radiation therpy at the Massachusetts General Hospital(MGH) for retroperitoneal soft tissue sarcomas. Seventeen patients were treated with curative intent and six with palliative intent. Of the patients treated with curative intent, the 5 year actuarial survivial rate was 54% and the 5 year actuarial local control rate was also 54%.

Joel E Tepper; Herman D Suit; William C Wood; Karl H Proppe; David Harmon; Pat McNulty

1984-01-01

177

Radiation Therapy for Cushing's Disease: A Review  

Microsoft Academic Search

Because patients with Cushing's disease have an increased morbidity and an age-corrected mortality, treatment is generally started as soon as possible. The goal of treatment in these patients is to induce remission. Although a variety of treatments are available, pituitary radiation is a good option for aggressive Cushing's disease that fails to respond to surgery, disease that invades the cavernous

Ashraf S. Mahmoud-Ahmed; John H. Suh

2002-01-01

178

BremsstrahlungRadiation Dose in Yttrium90 Therapy Applications  

Microsoft Academic Search

gible, especially considering the amounts of activity which may be used in Mab therapy. Simpkin et al. (4) studied the spatial distribution of energy deposition from bremsstrah lung radiation near point sources in a water medium. In this paper, we will further investigate the importance of this effect through evaluation of the results of Williams et al. against calculations using

Michael G. Stabin; Keith F. Eckerman; Jeffrey C. Ryman; Lawrence E. Williams

179

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

180

A Control System for a Radiation Therapy Machine  

Microsoft Academic Search

Abstract This report describes a new computer control system for a radiation therapy machine,with an isocentric gantry and a multileaf collimator. It discusses the motivation and rationale for some of the features and development activities, and reports several measures of development effort, performance, and quality, determined after almost two years of operating experience. Notable features of the control system include

Jonathan Jacky; Ruedi Risler; David Reid; Robert Emery; Jonathan Unger; Michael Patrick

2001-01-01

181

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

E-print Network

Roadmap: Radiologic Imaging Sciences - Radiation Therapy (with AAS Radiologic Technology) ­ Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-RTAA] Regional College Catalog Year Hours] Note: Students must have earned an AAS degree in Radiologic Technology (36 semester credits from

Sheridan, Scott

182

The potential of proton beam radiation therapy in breast cancer  

Microsoft Academic Search

A group of Swedish oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy. The estimations have been based on current statistics of tumour incidence, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours and

Thomas Björk-Eriksson; Bengt Glimelius

2005-01-01

183

High resolution optical calorimetry for synchrotron microbeam radiation therapy  

Microsoft Academic Search

We propose the application of optical calorimetry to measure the peak to valley ratio for synchrotron microbeam radiation therapy (MRT). We use a modified Schlieren approach known as reference image topography (RIT) which enables one to obtain a map of the rate of change of the refractive index in a water bath from which the absorbed dose can be determined

T. Ackerly; J. C. Crosbie; A. Fouras; G. J. Sheard; S. Higgins; R. A. Lewis

2011-01-01

184

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

185

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

186

Prostate angiosarcoma: is there any association with previous radiation therapy?  

PubMed Central

For the current review a literature search was carried out using Pubmed, EmBase, and Cochrane databases. All cases of prostate angioscaroma reported to date and observational studies evaluating the radiation associated cancer occurrence were reviewed. Despite the rarity, prostate angiosarcomas display remarkable clinical and pathological heterogeneity, and a treatment challenge. We found the association of prostate angiosarcoma with radiation therapy to be weak based upon the results from observational studies and case reports. Although radiation exposure has been suggested etiology of prostate angiosarcomas, assumption of such association is not supported by the current literature. PMID:22583810

Khaliq, Waseem; Meyer, Christian F.; Uzoaru, Ikechukwu; Wolf, Richard M.; Antonarakis, Emmanuel S.

2013-01-01

187

Patchy myocardial fibrosis 20 years after radiation therapy.  

PubMed

We describe a case of a young woman diagnosed with Ewings sarcoma at age 8 and treated with adriamycin and radiation therapy. Twenty years later the patient has a cardiomyopathy and a focal area of patchy infiltration of fibrotic tissue along the left ventricle and atrium. Although fibrosis due to radiation exposure has been demonstrated on biopsy and autopsy studies, we are not aware of previous reports of echocardiographic demonstration of this finding. The most likely explanation for the fibrosis location is the left posterolateral direction of the radiation beam. PMID:17214625

Wyman, Rachael A; Rahko, Peter S

2007-01-01

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

Chronic damage after radiation therapy: challenge to radiation biology  

SciTech Connect

After local irradiation of the heart or the recto-sigmoid of rats, chronic radiation damage develops after several months, leading to well-defined clinical syndromes of fatal pericarditis and myocardial necrosis or fatal ileus. In both organs, the LD-50 is below 20 Gy, and a pronounced split dose recovery has been measured with fractionated irradiation. In both organs, the primary radiation damage appears to be to the capillaries, which then leads to secondary parenchymal atrophy. Damage to structured vessels and fibrosis was only seen in areas of necrosis, which in the gut might be precipitated by secondary trauma to the atrophic mucosa.

Trott, K.R.

1984-06-01

190

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

191

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.

192

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 ...

193

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

MedlinePLUS

... To Know About Brachytherapy (A Type of Internal Radiation Therapy) “I asked questions. My doctor took the ... the part of your body being treated with radiation therapy. See the back of this sheet to ...

194

UC Davis research finds newer radiation therapy technology improves patients' quality of life:  

Cancer.gov

Patients with head and neck cancers who have been treated with newer, more sophisticated radiation therapy technology enjoy a better quality of life than those treated with older radiation therapy equipment, a study by UC Davis researchers has found.

195

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

Code of Federal Regulations, 2010 CFR

...charged-particle radiation therapy system is a device that produces by acceleration high energy charged particles (e.g., electrons and protons) intended for use in radiation therapy. This generic type of device may include signal analysis and display...

2010-04-01

196

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

MedlinePLUS

... AND HUMAN SERVICES National Institutes of Health Managing Radiation Therapy Side Effects What To Do When Your Mouth ... I take to help stop the pain? Managing Radiation Therapy Side Effects:What To Do When Your Mouth ...

197

Managing Radiation Therapy Side Effects: What to Do about Mild Skin Changes  

MedlinePLUS

... AND HUMAN SERVICES National Institutes of Health Managing Radiation Therapy Side Effects What To Do About Mild Skin ... nurse how to care for these areas. Managing Radiation Therapy Side Effects:What To Do About Mild Skin ...

198

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 Can ... my doctor before treatment.” Questions from women getting radiation therapy: What if I think I may be pregnant ...

199

High dose bystander effects in spatially fractionated radiation therapy.  

PubMed

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

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

2015-01-01

200

Research Findings on Radiation Hormesis and Radon Therapy  

SciTech Connect

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

Hattori, Sadao

1999-06-06

201

In vivo modification of Abeta plaque toxicity as a novel neuroprotective lithium-mediated therapy for Alzheimer’s disease pathology  

PubMed Central

Background Alzheimer’s disease (AD) is characterized by the abnormal accumulation of extracellular beta-amyloid (Abeta) plaques, intracellular hyperphosphorylated tau, progressive synaptic alterations, axonal dystrophies, neuronal loss and the deterioration of cognitive capabilities of patients. However, no effective disease-modifying treatment has been yet developed. In this work we have evaluated whether chronic lithium treatment could ameliorate the neuropathology evolution of our well characterized PS1M146LxAPPSwe-London mice model. Results Though beneficial effects of lithium have been previously described in different AD models, here we report a novel in vivo action of this compound that efficiently ameliorated AD-like pathology progression and rescued memory impairments by reducing the toxicity of Abeta plaques. Transgenic PS1M146LxAPPSwe-London mice, treated before the pathology onset, developed smaller plaques characterized by higher Abeta compaction, reduced oligomeric-positive halo and therefore with attenuated capacity to induce neuronal damage. Importantly, neuronal loss in hippocampus and entorhinal cortex was fully prevented. Our data also demonstrated that the axonal dystrophic area associated with lithium-modified plaques was highly reduced. Moreover, a significant lower accumulation of phospho-tau, LC3-II and ubiquitinated proteins was detected in treated mice. Our study highlights that this switch of plaque quality by lithium could be mediated by astrocyte activation and the release of heat shock proteins, which concentrate in the core of the plaques. Conclusions Our data demonstrate that the pharmacological in vivo modulation of the extracellular Abeta plaque compaction/toxicity is indeed possible and, in addition, might constitute a novel promising and innovative approach to develop a disease-modifying therapeutic intervention against AD. PMID:24252759

2013-01-01

202

A new radiation shielding block material for radiation therapy  

Microsoft Academic Search

In recent years, lead has been recognized as a source of environmental pollution; this includes lead use for radiation shielding in radiotherapy. We looked for a new material that could be a lead substitute. We chose a material composed of tungsten and resin. We compared the attenuation coefficient of the material with those of lead and Lipowitz's metal, and found

Minoru Tajiri; Masayoshi Sunaoka; Akifumi Fukumura; Masahiro Endo

2004-01-01

203

UPenn researchers find radiation plus hormone therapy prolongs survival for older men with prostate cancer  

Cancer.gov

Adding radiation treatment to hormone therapy saves more lives among older men with locally advanced prostate therapy than hormone therapy alone, according to a new study in the Journal of Clinical Oncology this week from Penn Medicine researchers.

204

Integrated breast conservation and intraoperative radiation therapy.  

PubMed

The introduction of innovative radiotherapy approaches for early breast cancer patients is rapidly changing the radiation oncologists' attitude and their expectations to obtain a good local control while decreasing morbidity therefore improving patient's quality of life. Intraoperative radiotherapy is a very attractive treatment modality in the multidisciplinary approach to breast conservation as is testified by the rapidly growing number of patients accrued in numerous studies all over Europe since 2000. A major advantage of intraoperative radiotherapy in breast cancer treatment is the administration of a large dose of radiation directly to the tumour bed, avoiding the possible geographic miss. Accurate localization and precise definition of the tumour bed volume is essential to achieve maximal efficacy in terms of local control while minimizing unnecessary damage to the normal breast tissue. Intraoperative radiotherapy reduces radiation exposure of the skin, lung, heart and normal subcutaneous tissues thus contributing to the low incidence of side effects and the generally excellent cosmetic results. Compared to other intraoperative techniques, the superiority of intraoperative radiotherapy appears to be the high homogeneity of dose distribution. The linear quadratic model used to calculate the biologic equivalent dose of intraoperative radiotherapy treatments for both tumour and normal tissue effects, is not considered totally reliable for large dose per fraction. The main concern is the potential increase in severe late side effects. Conversely, we expect an enhanced local control due to the radiobiologic efficacy of a large single dose delivered soon after tumour excision, with an immediate cell killing effect over any potential microscopic disease. The advantage of shortening the overall treatment time is that it avoids any delay in the administration of chemotherapy. The safety of intraoperative radiotherapy as a treatment modality in the context of breast conservation has been proved but conclusive data on local control and survival are expected from long term results of the ongoing studies. PMID:19914553

Orecchia, Roberto; Ivaldi, Giovanni Battista; Leonardi, Maria Cristina

2009-10-01

205

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

206

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

207

21 CFR 892.5900 - X-ray radiation therapy system.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false X-ray radiation therapy system. 892.5900... Therapeutic Devices § 892.5900 X-ray radiation therapy system. (a) Identification. An x-ray radiation therapy system is a device...

2012-04-01

208

21 CFR 892.5900 - X-ray radiation therapy system.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false X-ray radiation therapy system. 892.5900... Therapeutic Devices § 892.5900 X-ray radiation therapy system. (a) Identification. An x-ray radiation therapy system is a device...

2014-04-01

209

21 CFR 892.5900 - X-ray radiation therapy system.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false X-ray radiation therapy system. 892.5900... Therapeutic Devices § 892.5900 X-ray radiation therapy system. (a) Identification. An x-ray radiation therapy system is a device...

2011-04-01

210

21 CFR 892.5900 - X-ray radiation therapy system.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false X-ray radiation therapy system. 892.5900... Therapeutic Devices § 892.5900 X-ray radiation therapy system. (a) Identification. An x-ray radiation therapy system is a device...

2013-04-01

211

21 CFR 892.5900 - X-ray radiation therapy system.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false X-ray radiation therapy system. 892.5900... Therapeutic Devices § 892.5900 X-ray radiation therapy system. (a) Identification. An x-ray radiation therapy system is a device...

2010-04-01

212

Economic evaluation of proton radiation therapy in the treatment of breast cancer  

Microsoft Academic Search

Background and purposeProton beam therapy offers potential clinical advantages compared with conventional radiation therapy for many cancer patients. The benefits are mainly a result of a more favourable dose distribution. The treatment cost with proton radiation is higher than for conventional radiation, mainly due to the large investment cost of building a proton therapy facility. It is therefore important to

Jonas Lundkvist; Mattias Ekman; Suzanne Rehn Ericsson; Ulf Isacsson; Bengt Jönsson; Bengt Glimelius

2005-01-01

213

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

E-print Network

processing of serial 3D CT images used in image- guided radiation therapy. A major assumption in deformable methods, such as cone beam CT and CT-on-rails, that enable image guided radiation therapy as a way to meetLarge deformation 3D image registration in image-guided radiation therapy Mark Foskey, Brad Davis

Utah, University of

214

Preferential effect of synchrotron microbeam radiation therapy on intracerebral 9L gliosarcoma vascular networks  

E-print Network

Preferential effect of synchrotron microbeam radiation therapy on intracerebral 9L gliosarcoma.06.021 #12;Bouchet et al. 2010 2 Abstract Purpose. Synchrotron Microbeam Radiation Therapy (MRT) relies on the vasculature. Key words: Synchrotron Microbeam radiation therapy/intracerebral 9L gliosarcoma/tumor vasculature

Paris-Sud XI, Université de

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

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

SciTech Connect

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

Roach, M. III; Leidholdt, E.M. Jr.; Tatera, B.S.; Joseph, J. (Martinez VA Medical Center, CA (USA))

1990-06-01

217

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

218

Verification of synchrotron microbeam radiation therapy using a purpose-built optical CT microscope  

Microsoft Academic Search

This study presents an investigation of the use of 3-D dosimetry using optical computed tomography to provide verification of synchrotron microbeam radiation therapy (MRT). MRT is based on the remarkable tolerance of normal tissues to high doses of radiation when this dose is constrained to very narrow beams. At beamline ID17 of the European Synchrotron Radiation Facility, pre-clinical radiation therapy

A. T. Abdul Rahman; Elke Bräuer-Krisch; Thierry Brochard; John Adamovics; David Bradley; Simon Doran

2010-01-01

219

Radiation-force technique to monitor lesions during ultrasonic therapy.  

PubMed

This report describes a monitoring technique for high-intensity focused ultrasound (US), or HIFU, lesions, including protein-denaturing lesions (PDLs) and those made for noninvasive cardiac therapy and tumor treatment in the eye, liver and other organs. Designed to sense the increased stiffness of a HIFU lesion, this technique uniquely utilizes the radiation force of the therapeutic US beam as an elastographic push to detect relative stiffness changes. Feasibility was demonstrated with computer simulations (treating acoustically induced displacements, concomitant heating, and US displacement-estimation algorithms) and pilot in vitro experimental studies, which agree qualitatively in differentiating HIFU lesions from normal tissue. Detectable motion can be induced by a single 5 ms push with temperatures well below those needed to form a lesion. Conversely, because the characteristic heat diffusion time is much longer than the characteristic relaxation time following a push, properly timed multiple therapy pulses will form lesions while providing precise control during therapy. PMID:14654155

Lizzi, Frederic L; Muratore, Robert; Deng, Cheri X; Ketterling, Jeffrey A; Alam, S Kaisar; Mikaelian, Samuel; Kalisz, Andrew

2003-11-01

220

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

221

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

222

Radiation therapy for palliation of cancer-related chronic pain  

Microsoft Academic Search

Percutaneous radiotherapy is highly effective as a part of an interdisciplinary approach in the treatment of cancer-related\\u000a chronic pain. Overall response rates of 70–90% and complete pain relief rates of 40–50% have been reported in numerous retrospective\\u000a and randomized clinical trials. Beside the analgesic effect, radiation therapy enables the restoration of bony structure and\\u000a musculoskeletal function, improves patients’ mobility and

Arpad Sztankay

2009-01-01

223

Fibrosarcoma after high energy radiation therapy for pituitary adenoma  

SciTech Connect

Pituitary sarcoma is a rare late complication of radiotherapy for pituitary tumors. Although early case reports involved multiple courses of relatively low-energy radiation therapy, pituitary sarcoma has been seen with single courses of high-energy x-ray or heavy particle radiotherapy. This report describes a fibrosarcoma of the pituitary occurring 5 years after 4,500 rad (45 Gy) of x-irradiation delivered in 20 treatments over 3 weeks by an 8 MeV linear accelerator.

Martin, W.H. (Univ. of Virginia Medical Center, Charlottesville, VA); Cail, W.S.; Morris, J.L.; Constable, W.C.

1980-11-01

224

Analytical probabilistic modeling for radiation therapy treatment planning  

NASA Astrophysics Data System (ADS)

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

Bangert, Mark; Hennig, Philipp; Oelfke, Uwe

2013-08-01

225

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

PubMed

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

226

High grade angiosarcoma fifteen years after breast conservation therapy with radiation therapy: A case report  

PubMed Central

INTRODUCTION Angiosarcoma is a rare tumor of the breast. Secondary angiosarcoma of the breast refers specifically to a tumor that arises after a latency period following radiation. With breast conservation therapy gaining significant popularity to that of mastectomy, more cases of secondary angiosarcoma continue to arise in the irradiated fields of these patients. PRESENTATION OF CASE The authors describe the case of an 80 year old female who presented fifteen years after her surgery and radiation treatment with two bleeding skin lesions in her breast. These lesions were found to be high grade angiosarcoma upon excision. Due to high cardiac co-morbidity she was treated with re-excision and surveillance. DISCUSSION This case is an example of a rare sequela to a common procedure. Breast conservation therapy with lumpectomy and radiation has become a popular technique in treating localized breast cancer. Radiation like all therapy has its known adverse effects. Further work is needed with the small amount of published cases of angiosarcoma after breast irradiation so that we may find optimal treatment plans for these patients. Like any rare entity, difficulty lies in accruing enough cases to compare prognosis and results. CONCLUSION Secondary breast angiosarcoma diagnosis requires frequent follow ups and a high index of suspicion. With mastectomy giving the best chance of treatment in these cases, early detection is crucial in this rare sequela. PMID:25437669

Boyan, William; Farr, M.; Georges, Renee

2014-01-01

227

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

228

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

229

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

230

From intensity modulated radiation therapy to 4D radiation therapy--an advance in targeting mobile lung tumors.  

PubMed

Intensity modulated radiation therapy (IMRT) has been widely used in the treatment of lung cancer. The highly conformal dose distribution with steep gradients could miss the target if respiratory motion is not carefully considered during the treatment planning. The issue becomes particularly critical when dose escalation technique is used. To account for this periodical respiratory motion, the common practice is to add an empirical population-based safety margin to the clinical target volume (CTV). However, such a uniform margin does not reflect the fact that respiratory motion is not isotropic. In addition, it is not tailored to each individual patient. Thus, it is not optimal in both tumor targeting and normal tissue sparing. Here, we present our approach to 4D radiation therapy using the Bellows tracking system for targeting mobile lung tumors. The objective was to develop a clinically viable procedure for routine 4D treatment planning. PMID:18001930

Song, Yulin; Muller, Boris; Burman, Chandra; Mychalczak, Borys

2007-01-01

231

Radiation Survivors: Understanding and exploiting the phenotype following fractionated radiation therapy  

PubMed Central

Radiation oncology modalities such as intensity-modulated and image-guided radiation therapy can reduce the high dose to normal tissue and deliver a heterogeneous dose to tumors focusing on areas deemed at highest risk for tumor persistence. Clinical radiation oncology produces daily doses ranging from 1 to 20 Gy, with tissues being exposed to 30 or more daily fractions. Hypothesizing that cells that survive fractionated radiation therapy have a substantially different phenotype than the untreated cells, which might be exploitable for targeting with molecular therapeutics or immunotherapy, three prostate cancer cell lines (PC3, DU145 and LNCaP) and normal endothelial cells were studied to understand the biology of differential effects of multi-fraction (MF) radiation of 0.5, 1 and/or 2 Gy fraction to 10 Gy total dose, and a single dose (SD) of 5 and 10 Gy. The resulting changes in mRNA, miRNA and phosphoproteome were analyzed. Significant differences were observed in the MF radiation exposures including those from the 0.5 Gy MF that produces little cell killing. As expected, p53 function played a major role in response. Pathways modified by MF include immune response, DNA damage, cell cycle arrest, TGF-?, survival and apoptotic signal transduction. The radiation-induced stress response will set-forth a unique platform for exploiting the effects of radiation therapy as “focused biology” for cancer treatment in conjunction with molecular targeted or immunologically directed therapy. Given that more normal tissue is treated, albeit to lower doses with these newer techniques, the response of the normal tissue may also influence long-term treatment outcome. PMID:23175523

Makinde, Adeola Y.; John-Aryankalayil, Molykutty; Palayoor, Sanjeewani T.; Cerna, David; Coleman, C. Norman

2012-01-01

232

Radiation survivors: understanding and exploiting the phenotype following fractionated radiation therapy.  

PubMed

Radiation oncology modalities such as intensity-modulated and image-guided radiation therapy can reduce the high dose to normal tissue and deliver a heterogeneous dose to tumors, focusing on areas deemed at highest risk for tumor persistence. Clinical radiation oncology produces daily doses ranging from 1 to 20 Gy, with tissues being exposed to 30 or more daily fractions. Hypothesizing the cells that survive fractionated radiation therapy have a substantially different phenotype than the untreated cells, which might be exploitable for targeting with molecular therapeutics or immunotherapy, three prostate cancer cell lines (PC3, DU145, and LNCaP) and normal endothelial cells were studied to understand the biology of differential effects of multifraction (MF) radiation of 0.5, 1, and/or 2 Gy fraction to 10 Gy total dose, and a single dose of 5 and 10 Gy. The resulting changes in mRNA, miRNA, and phosphoproteome were analyzed. Significant differences were observed in the MF radiation exposures including those from the 0.5 Gy MF that produces little cell killing. As expected, p53 function played a major role in response. Pathways modified by MF include immune response, DNA damage, cell-cycle arrest, TGF-?, survival, and apoptotic signal transduction. The radiation-induced stress response will set forth a unique platform for exploiting the effects of radiation therapy as "focused biology" for cancer treatment in conjunction with molecular targeted or immunologically directed therapy. Given that more normal tissue is treated, albeit to lower doses with these newer techniques, the response of the normal tissue may also influence long-term treatment outcome. PMID:23175523

Makinde, Adeola Y; John-Aryankalayil, Molykutty; Palayoor, Sanjeewani T; Cerna, David; Coleman, C Norman

2013-01-01

233

TLD dosimetry for microbeam radiation therapy at the European Synchrotron Radiation Facility  

Microsoft Academic Search

A two-dimensional (2-D) thermoluminescence (TL) dosimetry system consisting of LiF:Mg,Cu,P (MCP-N)-based TL foils and a TLD reader equipped with a CCD camera and the large size (72mm in diameter) planchete heater, developed at the Institute of Nuclear Physics (IFJ PAN, was applied for 2-D dosimetry of X-ray microbeam radiation therapy (MRT) at the European Synchrotron Radiation Facility (ESRF) in Grenoble,

M. Ptaszkiewicz; E. Braurer-Kirsch; M. Klosowski; L. Czopyk; P. Olko

2008-01-01

234

Optimal approach in early breast cancer: Radiation therapy  

PubMed Central

Radiation therapy significantly reduces by at least 70% the relative risk of local and regional recurrences for breast cancer after surgery. A positive influence on overall survival has been clearly demonstrated, especially for patients with a high absolute risk for locoregional recurrences. However, this is partially counterbalanced by late toxicity (dependent upon the radiation dose) especially to cardiac structures. Apart from this toxicity, a clear influence of radiation-therapy-related factors on functional and cosmetic outcome has also been demonstrated. Over time, technical improvements have led to a marked reduction in dose to the neighbouring organs, with a consequent drop in acute and late toxicity. This has also allowed the introduction of shorter radiation schedules, lowering the burden of treatment to the patient and the hospital. Several tools, techniques and guidelines have been developed to optimise the balance between the desired reduction in recurrence rates and side effects. The multidisciplinary team should discuss all available treatment options for every individual breast cancer patient. Individualisation of the selection of the optimal combination of treatments, depending on patient and tumour-related factors, is of utmost importance. Apart from direct tumour-related outcomes, cosmesis and potential side effects have to be taken into account. Counselling should include known risk factors for survival and complications, including comorbidity.

Poortmans, Philip

2013-01-01

235

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

236

Effects of radiation therapy and chemotherapy on testicular function  

SciTech Connect

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

Kinsella, T.J. (Univ. of Wisconsin Clinical Cancer Center, Madison (USA))

1989-01-01

237

Melanoma Therapy via Peptide-Targeted a-Radiation  

SciTech Connect

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

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

2005-08-01

238

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

239

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

240

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

241

STUDY ON CHANGES IN PERIPHERAL BLOOD PATTERNS IN RADIATION THERAPY OF PATIENTS WITH UTERINE CARCINOMA  

Microsoft Academic Search

Hematologic effects are described in 159 patients submitted to x ; radiation therapy administered in 12-18 doses of 300-400 r. Hypochromic anemia ; was present in 2\\/3 of the cases before therapy, presumably as a result of chronic ; uterine bleeding, and a further reduction in hemoglobin occurred after therapy. ; The decrease in hemoglobin was proportional to the radiation

Takata

1960-01-01

242

Combining molecular targeted agents with radiation therapy for malignant gliomas  

PubMed Central

The expansion in understanding the molecular biology that characterizes cancer cells has led to the rapid development of new agents to target important molecular pathways associated with aberrant activation or suppression of cellular signal transduction pathways involved in gliomagenesis, including epidermal growth factor receptor, vascular endothelial growth factor receptor, mammalian target of rapamycin, and integrins signaling pathways. The use of antiangiogenic agent bevacizumab, epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib, mammalian target of rapamycin inhibitors temsirolimus and everolimus, and integrin inhibitor cilengitide, in combination with radiation therapy, has been supported by encouraging preclinical data, resulting in a rapid translation into clinical trials. Currently, the majority of published clinical studies on the use of these agents in combination with radiation and cytotoxic therapies have shown only modest survival benefits at best. Tumor heterogeneity and genetic instability may, at least in part, explain the poor results observed with a single-target approach. Much remains to be learned regarding the optimal combination of targeted agents with conventional chemoradiation, including the use of multipathways-targeted therapies, the selection of patients who may benefit from combined treatments based on molecular biomarkers, and the verification of effective blockade of signaling pathways. PMID:23966794

Scaringi, Claudia; Enrici, Riccardo Maurizi; Minniti, Giuseppe

2013-01-01

243

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. PMID:25210685

Kye, Bong-Hyeon

2014-01-01

244

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

SciTech Connect

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

Cui Yunfeng [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Galvin, James M. [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States) [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Radiation Therapy Oncology Group, American College of Radiology, Philadelphia, Pennsylvania (United States); Parker, William [Department of Medical Physics, McGill University Health Center, Montreal, QC (Canada)] [Department of Medical Physics, McGill University Health Center, Montreal, QC (Canada); Breen, Stephen [Department of Radiation Physics, Princess Margaret Hospital, Toronto, ON (Canada)] [Department of Radiation Physics, Princess Margaret Hospital, Toronto, ON (Canada); Yin Fangfang; Cai Jing [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)] [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Papiez, Lech S. [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); Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States)] [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Bednarz, Greg [Department of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States)] [Department of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Chen Wenzhou [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Xiao Ying, E-mail: ying.xiao@jefferson.edu [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Radiation Therapy Oncology Group, American College of Radiology, Philadelphia, Pennsylvania (United States)

2013-01-01

245

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

246

Image registration and data fusion in radiation therapy.  

PubMed

This paper provides an overview of image registration and data fusion techniques used in radiation therapy, and examples of their use. They are used at all stages of the patient management process; for initial diagnosis and staging, during treatment planning and delivery, and after therapy to help monitor the patients' response to treatment. Most treatment planning systems now support some form of interactive or automated image registration and provide tools for mapping information, such as tissue outlines and computed dose from one imaging study to another. To complement this, modern treatment delivery systems offer means for acquiring and registering 2D and 3D image data at the treatment unit to aid patient setup. Techniques for adapting and customizing treatments during the course of therapy using 3D and 4D anatomic and functional imaging data are currently being introduced into the clinic. These techniques require sophisticated image registration and data fusion technology to accumulate properly the delivered dose and to analyse possible physiological and anatomical changes during treatment. Finally, the correlation of radiological changes after therapy with delivered dose also requires the use of image registration and fusion techniques. PMID:16980689

Kessler, M L

2006-09-01

247

Third generation gold nanoplatform optimized for radiation therapy  

PubMed Central

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

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

2013-01-01

248

Strategies for quality assurance of intensity modulated radiation therapy  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

249

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

PubMed

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

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

2014-10-18

250

Regorafenib-induced transverse myelopathy after stereotactic body radiation therapy.  

PubMed

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

Tian, Sibo; Nissenblatt, Michael; Goyal, Sharad

2014-12-01

251

Cancer stem cells, cancer cell plasticity and radiation therapy.  

PubMed

Since the first prospective identification of cancer stem cells in solid cancers the cancer stem cell hypothesis has reemerged as a research topic of increasing interest. It postulates that solid cancers are organized hierarchically with a small number of cancer stem cells driving tumor growth, repopulation after injury and metastasis. They give rise to differentiated progeny, which lack these features. The model predicts that for any therapy to provide cure, all cancer stem cells have to be eliminated while the survival of differentiated progeny is less critical. In this review we discuss recent reports challenging the idea of a unidirectional differentiation of cancer cells. These reports provide evidence supporting the idea that non-stem cancer cells exhibit a remarkable degree of plasticity that allows them to re-acquire cancer stem cell traits, especially in the context of radiation therapy. We summarize conditions under which differentiation is reversed and discuss the current knowledge of the underlying mechanisms. PMID:25025713

Vlashi, Erina; Pajonk, Frank

2014-07-12

252

Current standards and future directions for prostate cancer radiation therapy.  

PubMed

Definitive radiation therapy is a well-recognized curative treatment option for localized prostate cancer. A suitable technique, dose, target volume and the option of a combination with androgen deprivation therapy need to be considered. An optimal standard external beam radiotherapy currently includes intensity-modulated and image-guided radiotherapy techniques with total doses of ?76-78 Gy in conventional fractionation. Protons or carbon ions are alternatives available only in specific centers. Data from several randomized studies increasingly support the rationale for hypofractionated radiotherapy. A simultaneous integrated boost with dose escalation focused on a computed tomography/PET- or MRI/magnetic resonance spectroscopy-detected malignant lesion is one option to increase tumor control, with potentially no additional toxicity. The application of a spacer is a promising concept for optimal protection of the rectal wall. PMID:23259429

Pinkawa, Michael; Schoth, Felix; Böhmer, Dirk; Hatiboglu, Gencay; Sharabi, Andrew; Song, Danny; Eble, Michael J

2013-01-01

253

Automatic Segmentation of Intra-Treatment CT Images for Adaptive Radiation Therapy of the  

E-print Network

Automatic Segmentation of Intra-Treatment CT Images for Adaptive Radiation Therapy of the Prostate describe our approach and present a study of its accuracy for adaptive radiation therapy of the prostate in a series of 40 or more daily treatments. To be safe and effective, the radiation dose to the cancer

254

Joint ToF Image Denoising and Registration with a CT Surface in Radiation Therapy  

E-print Network

Joint ToF Image Denoising and Registration with a CT Surface in Radiation Therapy Sebastian Bauer1 study we show its potential for improvements in radiation therapy planning and treatment. Our algorithm in radiation oncology [1]. Technolo- gies that allow an increased dose to the tumor while sparing healthy

Rumpf, Martin

255

Radiation Therapy at End-of-Life in Children.  

PubMed

Abstract Objective: Few data exist on evaluating utilization patterns of radiotherapy (RT) at the end of life (EOL) in children. Metastatic disease in pediatric patients is not pathognomonic for palliative treatment intent; further complicating the issue are complexities surrounding the very select population of children receiving proton therapy (PrT). We compared data for RT and PrT in terms of death rate within 30 days. Methods: We performed chart reviews for patients receiving radiation therapy at age ?21 years treated at Indiana University Health Proton Therapy Center (IUHPTC) between June 2008 and June 2013 and University of Miami Radiation Oncology Department (UM) between June 2000 and June 2013. Included were patients not completing prescribed courses of RT, and those dying within 30 days of therapy. Comparison was made of differences between practice data for PrT and conventional RT. Results: At IUHPTC, 2 children of 272 did not complete their courses and died within 30 days (0.7%). At UM, data are available for 425 children; 9 did not complete their courses and 7 died within 30 days (1.6%). Neither the number of patients who did not complete treatment nor the 30-day death rates (P=.21) for PrT and RT were significantly different. Conclusions: Delivery of RT for children at EOL is complex. Frequency of RT at EOL in children occurs in is <2% of cases, and is not significantly less frequent in the proton milieu. This appears to be about an order of magnitude less than in adults. PMID:25216446

Panoff, Joseph; Simoneaux, R Victor; Shah, Nikesh; Scott, Michael; Buchsbaum, Jeffrey C; Johnstone, Peter A S; McMullen, Kevin P

2014-09-12

256

A method for evaluating quality assurance needs in radiation therapy.  

PubMed

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

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

2008-01-01

257

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

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

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

Code of Federal Regulations, 2011 CFR

...for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...be licensed as Radiographers, Nuclear Medicine Technologists, or Radiation...

2011-10-01

260

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

Code of Federal Regulations, 2010 CFR

...for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...be licensed as Radiographers, Nuclear Medicine Technologists, or Radiation...

2010-10-01

261

Radiation Therapy for Prevention of Heterotopic Ossification about the Elbow  

Microsoft Academic Search

\\u000a \\u000a Purpose:\\u000a   To evaluate the radiologic and functional outcome after prophylactic radiation therapy (RT) for prevention of heterotopic\\u000a ossification (HO) about the elbow joint.\\u000a \\u000a \\u000a \\u000a \\u000a Patients and Methods:\\u000a   20 patients with symptomatic HO were treated using perioperative single-dose RT of 7.0 Gy. 15 patients had excision of preexisting\\u000a functionally relevant HO, and received RT for prevention of a recurrence, and five patients

Reinhard Heyd; Thomas Buhleier; Nikolaos Zamboglou

2009-01-01

262

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.

263

Technical aspects of radiation therapy for anal cancer  

PubMed Central

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

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

2014-01-01

264

Monte Carlo dose enhancement studies in microbeam radiation therapy  

SciTech Connect

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

Martinez-Rovira, I.; Prezado, Y. [ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), B.P. 220, 6 rue Jules Horowitz, F-38043 Grenoble Cedex, France and Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, E-08028 Barcelona (Spain); ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), B.P. 220, 6 rue Jules Horowitz, F-38043 Grenoble Cedex (France)

2011-07-15

265

Preoperative intensity modulated radiation therapy for retroperitoneal sarcoma.  

PubMed

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

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

2014-06-01

266

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

267

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

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

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

SciTech Connect

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

Okumura, Toshiyuki; Itai, Yuji; Tsuji, Hiroshi [Central Hospital of Ibaraki (Japan)] [and others

1994-09-01

270

Subacute brain atrophy after radiation therapy for malignant brain tumor  

SciTech Connect

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

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

1989-05-15

271

Effect of endobronchial radiation therapy on malignant bronchial obstruction  

SciTech Connect

We evaluated the effect of endobronchial radiation therapy in 52 patients with malignant airway occlusion. Fifty-five endobronchial applications of the radioisotope iridium 192 were carried out. Response was assessed by change in performance status, symptom resolution, duration of symptom relief, roentgenographic reaeration, pulmonary function tests, and postimplant bronchoscopy. Thirty-three patients showed at least a one-level improvement in performance status. Of a total of 166 symptoms present prior to therapy, 131 resolved or improved. Approximately 70 percent of a patient's lifetime was rendered symptom improved or symptom free. A roentgenographic reaeration response of 30/41 (73 percent) was achieved. The average FEV1 and FVC improved from 1.5 to 2.1 L and from 2.3 to 2.9 L, respectively. Posttherapy bronchoscopy was performed between one and two months following the implant in 15 patients who agreed to undergo the procedure. Eleven (73 percent) of 15 had complete tumor regression. Major long-term complications were noted in seven patients. Endobronchial radiation, therefore, appears to be a safe and effective technique to palliate malignant airway occlusion.

Mehta, M.; Shahabi, S.; Jarjour, N.; Steinmetz, M.; Kubsad, S. (Univ. of Wisconsin Medical School, Madison (USA))

1990-03-01

272

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

273

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

PubMed Central

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

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

2011-01-01

274

NLM Director’s Comments Transcript - Use of Short Term Radiation Therapy  

MedlinePLUS

NLM Director’s Comments Transcript Use of Short Term Radiation Therapy: 02/17/2015 To use the sharing ... what's new this week in MedlinePlus. Short term radiation treatment (following breast cancer lumpectomies) is increasing for ...

275

Microwave Thermoablation for Localized Prostate Cancer After Failed Radiation Therapy: Role of Neoadjuvant Hormonal Therapy.  

PubMed

The treatment of residual prostate cancer after irradiation is often associated with significant morbidity and a high failure rate. Percutaneous transperineal interstitial microwave thermoablation is a minimally invasive procedure used experimentally in our institution to treat selected patients with failures of external-beam radiation therapy for prostate cancer. The aim is to ablate all residual intraprostatic cancer thermally. Patients were treated under general or epidural anesthesia with transrectal ultrasound guidance of transperineal placement of the microwave antennas. The rectum, urethra, and a developed space between the prostate and surrounding tissues were actively cooled. The minimal target temperature of the prostate was 65 degrees C for 15 min. The temperature was measured in all cases with interstitial prostatic thermosensors and in selected cases with online magnetic resonance scanning. Thirty-seven patients with apparently localized prostate cancer after failure of treatment for cure with external-beam therapy were subjected to this treatment, and 20 of these patients have at least 12 months of follow-up. The initial prostate specific antigen (PSA) concentration ranged from 0.2 to 120 ng/mL. At 12 months, 12 of 20 patients had no biochemical or histologic evidence of disease, and 11 of 14 patients with initial PSA concentration <10 ng/mL had no evidence of disease. Five of the thirty-seven patients were treated with 3 months of neoadjuvant androgen ablation because the volume of their prostates precluded adequate heating. The average volume decline was 28%, which allowed all men to be treated. Two of these patients have been followed for at lease 1 year, and neither shows evidence of recurrence. Side effects of treatment in all patients were modest. Preliminary results suggest that this treatment might be useful in selected patients as a salvage therapy after failure of radiation therapy for localized prostate cancer. PMID:10851330

Trachtenberg; Chen; Kucharczyk; Toi; Lancaster

1999-01-01

276

Cord blood-derived cytokine-induced killer cellular therapy plus radiation therapy for esophageal cancer: a case report.  

PubMed

Esophageal cancer is a serious malignancy with regards to mortality and prognosis. Current treatment options include multimodality therapy mainstays of current treatment including surgery, radiation, and chemotherapy. Cell therapy for esophageal cancer is an advancing area of research. We report a case of esophageal cancer following cord blood-derived cytokine-induced killer cell infusion and adjuvant radiotherapy. Initially, she presented with poor spirit, full liquid diets, and upper abdominal pain. Through cell therapy plus adjuvant radiotherapy, the patient remitted and was self-reliant. Recognition of this curative effect of sequent therapy for esophageal cancer is important to enable appropriate treatment. This case highlights cord blood-derived cytokine-induced killer cell therapy significantly alleviates the adverse reaction of radiation and improves the curative effect. Cell therapy plus adjuvant radiotherapy can be a safe and effective treatment for esophageal cancer. PMID:25526496

Wang, Liming; Huang, Shigao; Dang, Yazheng; Li, Ming; Bai, Wen; Zhong, Zhanqiang; Zhao, Hongliang; Li, Yang; Liu, Yongjun; Wu, Mingyuan

2014-12-01

277

ASSESSMENT OF THE RISK FOR DEVELOPING A SECOND MALIGNANCY FROM SCATTERED AND SECONDARY RADIATION IN RADIATION THERAPY  

PubMed Central

With the average age of radiation therapy patients decreasing and the advent of more complex treatment options comes the concern that the incidences of radiation-induced cancer might increase in the future. The carcinogenic effects of radiation are not well understood for the entire dose range experienced in radiation therapy. Longer epidemiological studies are needed to improve current risk models and reduce uncertainties of current risk model parameters. On the other hand, risk estimations are needed today to judge the risks vs. benefits of modern radiation therapy techniques. This paper describes the current state-of-the-art in risk modeling for radiation-induced malignancies in radiation therapy, distinguishing between two volumes. First, the organs within the main radiation field receiving low or intermediate doses (typically between 0.1 and 50 Gy). Second, the organs far away from the treatment volume receiving low doses mainly due to scattered and secondary radiation (typically below 0.1 Gy). The dosimetry as well as the risk model formalisms are outlined. Furthermore, example calculations and results are presented for intensity-modulated photon therapy vs. proton therapy. PMID:23032895

Paganetti, Harald

2012-01-01

278

MOSFET dosimetry for microbeam radiation therapy at the European Synchrotron Radiation Facility  

Microsoft Academic Search

Preclinical experiments are carried out with ;20–30 mm wide, ;10 mm high parallel microbeams of hard, broad-‘‘white’’-spectrum x rays ~;50–600 keV! to investigate microbeam radiation therapy ~MRT! of brain tumors in infants for whom other kinds of radiotherapy are inadequate and\\/or unsafe. Novel physical microdosimetry ~implemented with MOSFET chips in the ‘‘edge-on’’ mode! and Monte Carlo computer-simulated dosimetry are described

E. Brauer-Krisch; A. Bravin; M. L. Lerch; A. Rosenfeld; J. Stepanek; M. Di Michiel; J. A. Laissue

2003-01-01

279

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

280

Radiation therapy for the treatment of benign vascular, skeletal and soft tissue diseases  

Microsoft Academic Search

The concept of radiation therapy for the treatment of benign diseases refers to the use of moderate to high-energy ionising\\u000a radiation as part of the treatment of non-malignant, but not necessarily harmless, diseases. The usefulness of radiation therapy,\\u000a based on the anti-inflammatory properties of ionising radiation, has long been known. Apart from the treatment of intracranial\\u000a benign tumours, such as

Ángel Montero Luis; Raúl Hernanz de Lucas; Asunción Hervás Morón; Eva Fernández Lizarbe; Sonsoles Sancho García; Carmen Vallejo Ocaña; Alfredo Polo Rubio; Alfredo Ramos Aguerri

2008-01-01

281

Non-invasive detection of vulnerable coronary plaque  

PubMed Central

Critical coronary stenoses have been shown to contribute to only a minority of acute coronary syndromes and sudden cardiac death. Autopsy studies have identified a subgroup of high-risk patients with disrupted vulnerable plaque and modest stenosis. Consequently, a clinical need exists to develop methods to identify these plaques prospectively before disruption and clinical expression of disease. Recent advances in invasive and non-invasive imaging techniques have shown the potential to identify these high-risk plaques. Non-invasive imaging with magnetic resonance imaging, computed tomography and positron emission tomography holds the potential to differentiate between low- and high-risk plaques. There have been significant technological advances in non-invasive imaging modalities, and the aim is to achieve a diagnostic sensitivity for these technologies similar to that of the invasive modalities. Molecular imaging with the use of novel targeted nanoparticles may help in detecting high-risk plaques that will ultimately cause acute myocardial infarction. Moreover, nanoparticle-based imaging may even provide non-invasive treatments for these plaques. However, at present none of these imaging modalities are able to detect vulnerable plaque nor have they been shown to definitively predict outcome. Further trials are needed to provide more information regarding the natural history of high-risk but non-flow-limiting plaque to establish patient specific targeted therapy and to refine plaque stabilizing strategies in the future. PMID:21860703

Sharif, Faisal; Lohan, Derek G; Wijns, William

2011-01-01

282

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

283

Interactive 3D dose volume visualization in radiation therapy  

NASA Astrophysics Data System (ADS)

The major aim of conformal therapy is to engulf the tumor volume by a high radiation dose while minimizing the exposure of the surrounding healthy tissue. Visualization of the tumor volume, dose, and surrounding tissue is an important step in determining if the proposed treatment plan is optimal or even acceptable. This paper investigates the use of interactive volume visualization for the dose volume as well as the anatomical data. A commercially available volumetric processor capable of computing 10 million transformed and trilinearly interpolated points per second is used to generate multiplanar reformatted (MPR) and 3D displays of patient anatomy and radiation dose. The dose is treated as a volume data set in it's own right, which allows for the arbitrary selection of any isodose surface with interactive control of dose level and relative beam weights for multi beam treatment plans. A coarse-to-fine strategy is employed for all viewing modes. MPR views are generated at the rate of approximately 10 frames per second with 3D displays taking approximately 10 seconds per view. Clinically useful images, indicating the variation of radiation dose levels combined with 3D anatomy, can be generated interactively, allowing for the rapid evaluation of complex treatment plans.

Root, Gary; Sims, C.; Pillutla, R.; Goldwasser, Samuel M.

1994-09-01

284

Stereotactic multibeam radiation therapy system in a PACS environment  

NASA Astrophysics Data System (ADS)

A Multibeam radiation therapy treatment is a non-invasive technique devoted to treat a lesion within the cerebral medium by focusing photon-beams on the same target from a high number of entrance points. We present here a computer assisted dosimetric planning procedure which includes: (1) an analysis module to define the target volume by using 2D and 3D displays, (2) a planing module to issue a treatment strategy including the dosimetric simulations and (3) a treatment module setting up the parameters to order the robotized treatment system (i.e. chair- framework, radiation unit machine). Another important feature of this system is its connection to the PACS system SIRENE settled in the University hospital of Rennes which makes possible the archiving and the communication of the multimodal images (CT, MRI, Angiography) used by this application. The corporate use of stereotactic methods and the multimodality imagery ensures spatial coherence and makes the target definition and the cognition of the structures environment more accurate. The dosimetric planning suited to the spatial reference (i.e. the stereotactic frame) guarantees an optimal distribution of the dose computed by an original 3D volumetric algorithm. The robotic approach of the treatment stage has consisted to design a computer driven chair-framework cluster to position the target volume at the radiation unit isocenter.

Fresne, Francoise; Le Gall, G.; Barillot, Christian; Gibaud, Bernard; Manens, Jean-Pierre; Toumoulin, Christine; Lemoine, Didier; Chenal, C.; Scarabin, Jean-Marie

1991-05-01

285

Radiation Therapy Using High-Energy Carbon Beams  

NASA Astrophysics Data System (ADS)

Heavy-ion radiotherapy using high-energy carbon beams has been performed at the National Institute of Radiological Sciences, Japan. The physical frameworks for heavy-ion radiotherapy are established using an understanding of radiation physics. In this chapter, the biophysical and medical physics aspects of heavy-ion radiotherapy are presented. In order to increase the accuracy of heavy-ion radiotherapy, many physical problems should be solved. A calorimeter was developed to measure the absolute dose of the heavy-ion beams. From a comparison of the dosimetry, it was found that the dose indicated by the ionization chamber was underestimated by 3-4%. The clinical results of carbon therapy at heavy-ion medical accelerator in Chiba (HIMAC) are assessed using the linear-quadratic (LQ) model of radiation effect. Development of new scintillation and Rossi counters will allow simultaneous measurement of the radiation dose and quality of heavy-ion beams. Further research is required to provide a comprehensive biophysical model for clinical applications.

Kanai, T.

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

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

SciTech Connect

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

Alqathami, Mamdooh, E-mail: malq7704@uni.sydney.edu.au [Discipline of Medical Radiations, The Royal Melbourne Institute of Technology University, Victoria (Australia)] [Discipline of Medical Radiations, The Royal Melbourne Institute of Technology University, Victoria (Australia); Blencowe, Anton [Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria (Australia)] [Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria (Australia); Yeo, Un Jin [School of Applied Sciences and Health Innovations Research Institute, The Royal Melbourne Institute of Technology University, Victoria (Australia)] [School of Applied Sciences and Health Innovations Research Institute, The Royal Melbourne Institute of Technology University, Victoria (Australia); Doran, Simon J. [CRUK and EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton (United Kingdom)] [CRUK and EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton (United Kingdom); Qiao, Greg [Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria (Australia)] [Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria (Australia); Geso, Moshi [Discipline of Medical Radiations, The Royal Melbourne Institute of Technology University, Victoria (Australia)] [Discipline of Medical Radiations, The Royal Melbourne Institute of Technology University, Victoria (Australia)

2012-11-15

288

Brain tumors and synchrotron radiation: Methodological developments in quantitative brain perfusion imaging and radiation therapy  

SciTech Connect

High-grade gliomas are the most frequent type of primary brain tumors in adults. Unfortunately, the management of glioblastomas is still mainly palliative and remains a difficult challenge, despite advances in brain tumor molecular biology and in some emerging therapies. Synchrotron radiation opens fields for medical imaging and radiation therapy by using monochromatic intense x-ray beams. It is now well known that angiogenesis plays a critical role in the tumor growth process and that brain perfusion is representative of the tumor mitotic activity. Synchrotron radiation quantitative computed tomography (SRCT) is one of the most accurate techniques for measuring in vivo contrast agent concentration and thus computing precise and accurate absolute values of the brain perfusion key parameters. The methodological developments of SRCT absolute brain perfusion measurements as well as their preclinical validation are detailed in this thesis. In particular, absolute cerebral volume and blood brain barrier permeability high-resolution (pixel size <50x50 {mu}m{sup 2}) parametric maps were reported. In conventional radiotherapy, the treatment of these tumors remains a delicate challenge, because the damages to the surrounding normal brain tissue limit the amount of radiation that can be delivered. One strategy to overcome this limitation is to infuse an iodinated contrast agent to the patient during the irradiation. The contrast agent accumulates in the tumor, through the broken blood brain barrier, and the irradiation is performed with kilovoltage x rays, in tomography mode, the tumor being located at the center of rotation and the beam size adjusted to the tumor dimensions. The dose enhancement results from the photoelectric effect on the heavy element and from the irradiation geometry. Synchrotron beams, providing high intensity, tunable monochromatic x rays, are ideal for this treatment. The beam properties allow the selection of monochromatic irradiation, at the optimal energy, for a maximal dose deposit in the tumor, while sparing healthy tissues. The methodology, the associated dosimetry as well as the preclinical validation of iodine enhanced strereotactic synchrotron radiation therapy is developed in the thesis. Significant survival increases were obtained, especially when the delivery of iodine is coupled with a transient blood-brain-barrier opener. The two complementary methods developed in this thesis offer perspectives in the understanding of the glioma growth process and in their treatment by radiation therapy. They show the potential of synchrotron radiation for absolute high-resolution morphological and functional CT imaging, and for new therapeutic modalities using intense monochromatic x rays.

Adam, Jean-Francois [INSERM unite 647-RSRM, ESRF, 6, rue Jules Horrowitz, 38043 Grenoble Cedex (France)

2005-04-01

289

Pioneer F Plaque Symbology  

NASA Technical Reports Server (NTRS)

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

1972-01-01

290

The Vulnerable Plaque: the Real Villain in Acute Coronary Syndromes  

PubMed Central

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

Liang, Michael; Puri, Aniket; Devlin, Gerard

2011-01-01

291

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

292

American Society of Radiation Oncology Recommendations for Documenting Intensity-Modulated Radiation Therapy Treatments  

SciTech Connect

Despite the widespread use of intensity-modulated radiation therapy (IMRT) for approximately a decade, a lack of adequate guidelines for documenting these treatments persists. Proper IMRT treatment documentation is necessary for accurate reconstruction of prior treatments when a patient presents with a marginal recurrence. This is especially crucial when the follow-up care is managed at a second treatment facility not involved in the initial IMRT treatment. To address this issue, an American Society for Radiation Oncology (ASTRO) workgroup within the American ASTRO Radiation Physics Committee was formed at the request of the ASTRO Research Council to develop a set of recommendations for documenting IMRT treatments. This document provides a set of comprehensive recommendations for documenting IMRT treatments, as well as image-guidance procedures, with example forms provided.

Holmes, Timothy [St. Agnes Cancer Center, Baltimore, MD (United States)], E-mail: tholmes@stagnes.org; Das, Rupak [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Low, Daniel [Department of Radiation Oncology, Washington University, St. Louis, MO (United States); Yin Fangfang [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Balter, James [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Palta, Jatinder [Department of Radiation Oncology, University of Florida Health Science Center, Gainesville, FL (United States); Eifel, Patricia [University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

2009-08-01

293

Role of external radiation therapy in urinary cancers.  

PubMed

Invasive urinary tumors are relatively rare and their treatment may cause important changes in urinary, sexual, and social functions. A systematic review of external radiation therapy studies in urinary cancers has been carried out. This synthesis of the literature is based on data from meta-analysis, randomized and prospective trials, and retrospective studies. There are few controlled clinical trials using adjuvant or radical radiotherapy +/- chemotherapy in kidney, ureter, and urethra cancers; there are several reports of muscle-invasive bladder cancer using multimodality treatment: intravesical surgery and neo-adjuvant chemotherapy to radiotherapy or concomitant radiochemotherapy with organ preservation. The conclusions reached for renal cancer are controversial; urethra and ureter cancers data are few and inconclusive; sufficient data now exist in literature to demonstrate that conservative management with organ preservation, for muscle-invasive bladder cancer, is a valid alternative to radical cystectomy, viewed as the gold standard. PMID:17591812

Parisi, S; Troiano, M; Corsa, P; Raguso, A; Cossa, S; Piazzolla, E E; Munafò, T; Sanpaolo, G; Natuno, A; Maiello, E

2007-06-01

294

[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

295

[Radiation therapy of sinonasal natural killer/T-cell lymphoma].  

PubMed

Natural killer (NK)/T-cell lymphoma are part of lymphoproliferative diseases, they are rare in Europe and the United States but relatively common in Asia and South America. Natural killer (NK)/T-cell lymphoma present clinically as destructive lesions of the upper aerodigestive tract with perforation of deep structures of the face, destruction of the palate or an invasion of orbits. Treatment modalities of these lymphomas are still discussed because of the lack of available studies and the rarity of this disease. Radiotherapy provides a rapid control of the disease and is positioned as a major treatment of localized stages of NK/T-cell lymphoma of the nasal cavity. We therefore studied the different forms of radiation therapy in the early stages of nasal NK/T-cell lymphoma. PMID:24462054

Riet, F-G; Canova, C-H; Gabarre, J; Ben Hassine, S; Kamsu Kom, L; Mazeron, J-J; Feuvret, L

2014-03-01

296

Effects of radiation therapy on skeletal growth in childhood  

SciTech Connect

Ionizing radiation was used to treat childhood cancer long before the advent of chemotherapy, and it took little time for physicians to appreciate the deleterious effects it had on skeletal growth. The cause of this complication results predominantly from alteration of chondroblastic activity. This may stem directly from irradiation at the epiphyseal plate or indirectly from irradiation of glands that secrete growth-mediating hormones. The complication can go far beyond the obvious physical afflictions and extend into the psychologic domain, rendering deeper, more permanent scars. Presently, many of these effects are predictable, reducible, and treatable without compromising the cure that so often depends on the use of irradiation. Because of the complexities of childhood cancer therapy, strategies aimed at diminishing these effects are challenging. It is imperative that these effects be understood so that they can be reduced in current patients and prevented in future patients.33 references.

Goldwein, J.W. (Univ. of Pennsylvania School of Medicine, Philadelphia (USA))

1991-01-01

297

Combination of stereotactic ablative body radiation with targeted therapies.  

PubMed

Recent advances allow safe and effective delivery of ablative doses of radiation with stereotactic precision to tumours, resulting in very high levels of tumour control. Parallel advances in the understanding of tumour biology enable delivery of systemic drugs that selectively antagonise biological pathways in the tumour and surrounding microenvironment. Data is emerging that these treatments have synergistic effects that might further increase therapeutic efficacy, and they are therefore being increasingly used in combination, primarily in metastatic or recurrent disease. In this Review we summarise the biological rationale and clinical data for both sterotactic ablative radiotherapy (SABR) and targeted therapies, and the emerging experience with combination of these treatments. We describe potential pathways of cooperation in both tumour and normal tissue between SABR and targeted drugs, and, because fatal toxicities have been reported, we outline clinical precautions. PMID:25186046

Zeng, Jing; Baik, Christina; Bhatia, Shailender; Mayr, Nina; Rengan, Ramesh

2014-09-01

298

Has the use of computers in radiation therapy improved the accuracy in radiation dose delivery?  

NASA Astrophysics Data System (ADS)

Purpose: It is well recognized that computer technology has had a major impact on the practice of radiation oncology. This paper addresses the question as to how these computer advances have specifically impacted the accuracy of radiation dose delivery to the patient. Methods: A review was undertaken of all the key steps in the radiation treatment process ranging from machine calibration to patient treatment verification and irradiation. Using a semi-quantitative scale, each stage in the process was analysed from the point of view of gains in treatment accuracy. Results: Our critical review indicated that computerization related to digital medical imaging (ranging from target volume localization, to treatment planning, to image-guided treatment) has had the most significant impact on the accuracy of radiation treatment. Conversely, the premature adoption of intensity-modulated radiation therapy has actually degraded the accuracy of dose delivery compared to 3-D conformal radiation therapy. While computational power has improved dose calibration accuracy through Monte Carlo simulations of dosimeter response parameters, the overall impact in terms of percent improvement is relatively small compared to the improvements accrued from 3-D/4-D imaging. Conclusions: As a result of computer applications, we are better able to see and track the internal anatomy of the patient before, during and after treatment. This has yielded the most significant enhancement to the knowledge of "in vivo" dose distributions in the patient. Furthermore, a much richer set of 3-D/4-D co-registered dose-image data is thus becoming available for retrospective analysis of radiobiological and clinical responses.

Van Dyk, J.; Battista, J.

2014-03-01

299

Many Breast Cancer Patients Get Too Much Radiation Therapy, Research Suggests  

MedlinePLUS

... features on this page, please enable JavaScript. Many Breast Cancer Patients Get Too Much Radiation Therapy, Research Suggests ... Preidt Wednesday, December 10, 2014 Related MedlinePlus Pages Breast Cancer Radiation Therapy WEDNESDAY, Dec. 10, 2014 (HealthDay News) -- ...

300

Calcified basal ganglionic mass 12 years after radiation therapy for medulloblastoma  

SciTech Connect

A patient treated 12 years previously with an operation and radiation therapy for a medulloblastoma developed weakness of the left hand and perivascular calcification involving the right internal capsule and caudate nucleus. These findings are considered possible long-term complications of the radiation therapy.

Lichtor, T.; Wollmann, R.L.; Brown, F.D.

1984-04-01

301

Calcified basal ganglionic mass 12 years after radiation therapy for medulloblastoma  

Microsoft Academic Search

A patient treated 12 years previously with an operation and radiation therapy for a medulloblastoma developed weakness of the left hand and perivascular calcification involving the right internal capsule and caudate nucleus. These findings are considered possible long-term complications of the radiation therapy.

Terry Lichtor; Robert L. Wollmann; Frederick D. Brown

1984-01-01

302

An irradiation facility and a beam simulation program for proton radiation therapy  

Microsoft Academic Search

A new beam course dedicated to proton radiation therapy was constructed at NIRS (National Institute of Radiological Sciences, Japan. The vertical beamline, which is assumed to be suitable for radiation therapy, has a scalterer, wobbler magnets, monitor ionization chambers, a range shifter, a range modulator, a multileaf collimator and other patient-positioning devices. A simulation program for beam propagation in a

Tatsuaki Kanai; Kiyomitsu Kawachi; Takeshi Hiraoka

1991-01-01

303

Synchrotron Microbeam Radiation Therapy induces hypoxia in intracerebral gliosarcoma but not in the normal brain  

E-print Network

Synchrotron Microbeam Radiation Therapy induces hypoxia in intracerebral gliosarcoma University, 85748 Garching, Germany Key words: Synchrotron Microbeam Radiation Therapy - Brain Tumors;108(1):143-8" DOI : 10.1016/j.radonc.2013.05.013 #12;Bouchet et al. 2013 2 Abstract Purpose Synchrotron microbeam

Paris-Sud XI, Université de

304

Ultrasound-based guidance of intensity-modulated radiation therapy  

SciTech Connect

In ultrasound-guided intensity-modulated radiation therapy (IMRT) of prostate cancer, ultrasound imaging ascertains the anatomical position of patients during x-ray therapy delivery. The ultrasound transducers are made of piezoelectric ceramics. The same crystal is used for both ultrasound production and reception. Three-dimensional (3D) ultrasound devices capture and correlate series of 2-dimensional (2D) B-mode images. The transducers are often arranged in a convex array for focusing. Lower frequency reaches greater depth, but results in low resolution. For clear image, some gel is usually applied between the probe and the skin contact surface. For prostate positioning, axial and sagittal scans are performed, and the volume contours from computed tomography (CT) planning are superimposed on the ultrasound images obtained before radiation delivery at the linear accelerator. The planning volumes are then overlaid on the ultrasound images and adjusted until they match. The computer automatically deduces the offset necessary to move the patient so that the treatment area is in the correct location. The couch is translated as needed. The currently available commercial equipment can attain a positional accuracy of 1-2 mm. Commercial manufacturer designs differ in the detection of probe coordinates relative to the isocenter. Some use a position-sensing robotic arm, while others have infrared light-emitting diodes or pattern-recognition software with charge-couple-device cameras. Commissioning includes testing of image quality and positional accuracy. Ultrasound is mainly used in prostate positioning. Data for 7825 daily fractions of 234 prostate patients indicated average 3D inter-fractional displacement of about 7.8 mm. There was no perceivable trend of shift over time. Scatter plots showed slight prevalence toward superior-posterior directions. Uncertainties of ultrasound guidance included tissue inhomogeneities, speckle noise, probe pressure, and inter-observer variation. Some published studies detected improvement in treatment based on gastrointestinal toxicity and the reduction of prostate movement.

Fung, Albert Y.C. [Department of Radiation Oncology, Nebraska Medical Center, Omaha, NE (United States)]. E-mail: afung@unmc.edu; Ayyangar, Komanduri M. [Department of Radiation Oncology, Nebraska Medical Center, Omaha, NE (United States); Djajaputra, David [Department of Radiation Oncology, Nebraska Medical Center, Omaha, NE (United States); Nehru, Ramasamy M. [Department of Radiation Oncology, Nebraska Medical Center, Omaha, NE (United States); Enke, Charles A. [Department of Radiation Oncology, Nebraska Medical Center, Omaha, NE (United States)

2006-04-01

305

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

306

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

307

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

308

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

309

Automatic CT simulation optimization for radiation therapy: A general strategy  

SciTech Connect

Purpose: In radiation therapy, x-ray computed tomography (CT) simulation protocol specifications should be driven by the treatment planning requirements in lieu of duplicating diagnostic CT screening protocols. The purpose of this study was to develop a general strategy that allows for automatically, prospectively, and objectively determining the optimal patient-specific CT simulation protocols based on radiation-therapy goals, namely, maintenance of contouring quality and integrity while minimizing patient CT simulation dose. Methods: The authors proposed a general prediction strategy that provides automatic optimal CT simulation protocol selection as a function of patient size and treatment planning task. The optimal protocol is the one that delivers the minimum dose required to provide a CT simulation scan that yields accurate contours. Accurate treatment plans depend on accurate contours in order to conform the dose to actual tumor and normal organ positions. An image quality index, defined to characterize how simulation scan quality affects contour delineation, was developed and used to benchmark the contouring accuracy and treatment plan quality within the predication strategy. A clinical workflow was developed to select the optimal CT simulation protocols incorporating patient size, target delineation, and radiation dose efficiency. An experimental study using an anthropomorphic pelvis phantom with added-bolus layers was used to demonstrate how the proposed prediction strategy could be implemented and how the optimal CT simulation protocols could be selected for prostate cancer patients based on patient size and treatment planning task. Clinical IMRT prostate treatment plans for seven CT scans with varied image quality indices were separately optimized and compared to verify the trace of target and organ dosimetry coverage. Results: Based on the phantom study, the optimal image quality index for accurate manual prostate contouring was 4.4. The optimal tube potentials for patient sizes of 38, 43, 48, 53, and 58 cm were 120, 140, 140, 140, and 140 kVp, respectively, and the corresponding minimum CTDIvol for achieving the optimal image quality index 4.4 were 9.8, 32.2, 100.9, 241.4, and 274.1 mGy, respectively. For patients with lateral sizes of 43–58 cm, 120-kVp scan protocols yielded up to 165% greater radiation dose relative to 140-kVp protocols, and 140-kVp protocols always yielded a greater image quality index compared to the same dose-level 120-kVp protocols. The trace of target and organ dosimetry coverage and the ? passing rates of seven IMRT dose distribution pairs indicated the feasibility of the proposed image quality index for the predication strategy. Conclusions: A general strategy to predict the optimal CT simulation protocols in a flexible and quantitative way was developed that takes into account patient size, treatment planning task, and radiation dose. The experimental study indicated that the optimal CT simulation protocol and the corresponding radiation dose varied significantly for different patient sizes, contouring accuracy, and radiation treatment planning tasks.

Li, Hua, E-mail: huli@radonc.wustl.edu; Chen, Hsin-Chen; Tan, Jun; Gay, Hiram; Michalski, Jeff M.; Mutic, Sasa [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States)] [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Yu, Lifeng [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States)] [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Anastasio, Mark A. [Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63110 (United States)] [Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63110 (United States); Low, Daniel A. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States)] [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States)

2014-03-15

310

Commissioning and implementation of an implantable dosimeter for radiation therapy.  

PubMed

In this article we describe commissioning and implementation procedures for the Dose Verification System (DVS) with permanently implanted in vivo wireless, telemetric radiation dosimeters for absolute dose measurements. The dosimeter uses a semiconductor device called a metal-oxide semiconductor field-effect transistor (MOSFET) to measure radiation dose. A MOSFET is a transistor that is generally used for amplifying or switching electronic signals. The implantable dosimeter was implemented with the goal of verifying the dose delivered to radiation therapy patients. For the purpose of acceptance testing, commissioning, and clinical implementation and to evaluate characteristics of the dosimeter, the following tests were performed: 1) temperature dependence, 2) reproducibility,3) field size dependence, 4) postirradiation signal drift, 5) dependence on average dose rate, 6) linearity test, 7) angular dependence (different gantry angle position), 8) angular dependence (different DVS angle position), 9) dose rate dependence,10) irradiation depth dependence, 11) effect of cone-beam exposure to the dosimeter, and 12) multiple reading effect. The dosimeter is not currently calibrated for use in the kV range; nonetheless, the effect of the cone-beam procedure on the MOSFET dosimeter was investigated. Phantom studies were performed in both air and water using an Elekta Synergy S Beam-Modulator linear accelerator. Commissioning and clinical implementation for prostate cancer patients receiving external-beam radiation therapy were performed in compliance with the general recommendations given for in vivo dosimetry devices. The reproducibility test in water at human body temperature (37°C) showed a 1.4% absolute difference, with a standard deviation of 5.72 cGy (i.e., SD = 2.9%). The constancy test shows that the average readings at room temperature were 3% lower compared to the readings at human body temperature, with a SD = 2%. Measurements were not dependent upon field size. Due to postirradiation signal drift, the following corrections are suggested: -2.8%, -2%, 0.5%, and 2.5% for the readings taken after 0.5, 1, 5, or 10 min, respectively. Different gantry angles did not influence the readings. The maximum error was less than 1% with a maximum SD = 3.61 cGy (1.8%) for the gantry angle of 45°. However, readings are dependent on the dosimeter orientation. The average dose reading was 7.89 cGy (SD = 1.46 cGy) when CBCT imaging was used for the pelvis protocol, and when postirradiation measurement was taken at 2.5 min (expected 2-3 cGy). The clinical implementation of the implantable MOSFET dosimeters for prostate cancer radiation therapy is described. Measurements performed for commissioning show that the dosimeter, if used within specifications, provides sufficient accuracy for its intended use in clinical procedures. The postradiation signal drift, temperature dependence, variation of reproducibility, and rotational isotropy could be encountered if the dosimeter is used outside the manufacturer's specifications. The dosimeter can be used as a tool for quantifying dose at depth, as well as to evaluate adherence between planned doses and the delivered doses. Currently, the system is clinically implemented with ± 7% tolerance. PMID:23470929

Buzurovic, Ivan; Showalter, Timothy N; Studenski, Matthew T; Den, Robert B; Dicker, Adam P; Cao, Junsheng; Xiao, Ying; Yu, Yan; Harrison, Amy

2013-01-01

311

The efficacy of sucralfate suspension in the prevention of oral mucositis due to radiation therapy  

SciTech Connect

The purpose of this study was to assess the value of sucralfate suspension in prevention of oral mucositis and for reduction of oral pain in patients who develop mucositis during radiation therapy. The study was a double-blind, placebo-controlled, randomized prospective trial of a sucralfate suspension in the prevention and management of oral mucositis during radiation therapy. Oral mucositis was assessed using a quantitative scale and symptoms were assessed using visual analogue scales. The statistical model was developed to detect a 40% reduction in mucositis. No statistically significant reduction in mucositis was seen. Early during radiation therapy less oral pain was reported in the sucralfate group, but as treatment progressed all patients experienced pain. Patients in the sucralfate group were prescribed topical and systemic analgesics later in the course of radiation therapy. Prophylactic oral rinsing with sucralfate did not prevent oral ulcerative mucositis. Sucralfate may reduce the experience of pain during radiation therapy. 32 refs., 3 tabs.

Epstein, J.B.; Wong, F.L.W. (British Columbia Cancer Agency, Vancouver (Canada))

1994-02-01

312

Patient Specification Quality Assurance for Glioblastoma Multiforme Brain Tumors Treated with Intensity Modulated Radiation Therapy  

PubMed Central

The aim of this study was to evaluate the significance of performing patient specification quality assurance for patients diagnosed with glioblastoma multiforme treated with intensity modulated radiation therapy. The study evaluated ten intensity modulated radiation therapy treatment plans using 10 MV beams, a total dose of 60 Gy (2 Gy/fraction, five fractions a week for a total of six weeks treatment). For the quality assurance protocol we used a two-dimensional ionization-chamber array (2D-ARRAY). The results showed a very good agreement between the measured dose and the pretreatment planned dose. All the plans passed >95% gamma criterion with pixels within 5% dose difference and 3 mm distance to agreement. We concluded that using the 2D-ARRAY ion chamber for intensity modulated radiation therapy is an important step for intensity modulated radiation therapy treatment plans, and this study has shown that our treatment planning for intensity modulated radiation therapy is accurately done. PMID:21850196

Al-Mohammed, H. I.

2011-01-01

313

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).

314

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

315

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

316

A Phase III Study of Conventional Radiation Therapy Plus Thalidomide Versus Conventional Radiation Therapy for Multiple Brain Metastases (RTOG 0118)  

SciTech Connect

Purpose: To compare whole-brain radiation therapy (WBRT) with WBRT combined with thalidomide for patients with brain metastases not amenable to resection or radiosurgery. Patients and Methods: Patients with Zubrod performance status 0-1, MRI-documented multiple (>3), large (>4 cm), or midbrain brain metastases arising from a histopathologically confirmed extracranial primary tumor, and an anticipated survival of >8 weeks were randomized to receive WBRT to a dose of 37.5 Gy in 15 fractions with or without thalidomide during and after WBRT. Prerandomization stratification used Radiation Therapy Oncology Group (RTOG) Recursive Partitioning Analysis (RPA) Class and whether post-WBRT chemotherapy was planned. Endpoints included overall survival, progression-free survival, time to neurocognitive progression, the cause of death, toxicities, and quality of life. A protocol-planned interim analysis documented that the trial had an extremely low probability of ever showing a significant difference favoring the thalidomide arm given the results at the time of the analysis, and it was therefore closed on the basis of predefined statistical guidelines. Results: Enrolled in the study were 332 patients. Of 183 accrued patients, 93 were randomized to receive WBRT alone and 90 to WBRT and thalidomide. Median survival was 3.9 months for both arms. No novel toxicities were seen, but thalidomide was not well tolerated in this population. Forty-eight percent of patients discontinued thalidomide because of side effects. Conclusion: Thalidomide provided no survival benefit for patients with multiple, large, or midbrain metastases when combined with WBRT; nearly half the patients discontinued thalidomide due to side effects.

Knisely, Jonathan P.S. [Department of Therapeutic Radiology, Yale University School of Medicine and Yale Cancer Center, New Haven, CT (United States)], E-mail: jonathan.knisely@yale.edu; Berkey, Brian [Radiation Therapy Oncology Group, Philadelphia, PA (United States); Chakravarti, Arnab [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Yung, Al W.K. [Department of Neuro-Oncology and Brain Tumor Center, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Curran, Walter J. [Department of Radiation Oncology, Emory University, Atlanta, GA (United States); Robins, H. Ian [Department of Human Oncology, University of Wisconsin Medical School, Madison, WI (United States); Department of Medicine, University of Wisconsin Medical School, Madison, WI (United States); Movsas, Benjamin [Department of Radiation Oncology, Henry Ford Health System, Detroit, MI (United States); Brachman, David G. [Department of Radiation Oncology, AZ Oncology Services and St. Joseph's Hospital, Phoenix, AZ (United States); Henderson, Randall H. [University of Florida Proton Therapy Institute, Jacksonville, FL (United States); Mehta, Minesh P. [Department of Medicine, University of Wisconsin Medical School, Madison, WI (United States)

2008-05-01

317

Abstract--Because the position of a tumor changes during radiation therapy (because of respiration or patient movements),  

E-print Network

Abstract-- Because the position of a tumor changes during radiation therapy (because of respiration of the tumor changes during radiation therapy (because of respiration, gastro-intestinal, cardiac system

Fowler, Mark

318

Acute effects of radiation therapy on indium-111-labeled leukocyte uptake in bone marrow  

SciTech Connect

We recently performed ({sup 99m}Tc)MDP bone and {sup 111}In-labeled leukocyte scintigraphy on a patient receiving radiation therapy to the lower cervical and upper thoracic spine. While the bone images revealed only minimally increased activity in the radiation port, leukocyte images revealed diffuse, intensely increased uptake in this same region. Radiation therapy should be included in the differential diagnosis of increased bone marrow activity on {sup 111}In leukocyte images.

Palestro, C.J.; Kim, C.K.; Vega, A.; Goldsmith, S.J. (Andre Meyer Department of Physics-Nuclear Medicine, New York, NY (USA))

1989-11-01

319

Management of optic pathway and chiasmatic-hypothalamic gliomas in children with radiation therapy  

Microsoft Academic Search

Background and purpose: Optic pathway and chiasmatic-hypothalamic gliomas are rare childhood tumors. This study presents the experience in management of these tumors with radiation therapy.Materials and methods: Thirty-three children with the diagnosis of optic pathway and chiasmatic-hypothalamic gliomas were treated with radiation therapy from 1973 through 1994 in the Department of Radiation Oncology at Ankara University Faculty of Medicine. Twenty-four

Haldun ?ükrü Erkal; Meltem Serin; Ahmet Çakmak

1997-01-01

320

Positron emission tomography with fluorodeoxyglucose to evaluate tumor response and control after radiation therapy  

Microsoft Academic Search

Following radiation therapy, evaluation of viable tumor can often be difficult with anatomic imaging criteria (tumor size alone). In this study, the utility of biochemical imaging with the glucose analog 2-[F-18]fluoro-2-deoxy-D-glucose and positron emission tomography was investigated in patients with radiation therapy. Post-radiation positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose studies were done in all patients, with 9 head and neck patients

Lisa Chaiken; G. Juillard; S. Rege; C. Hoh; Y. Choi; B. Jabour; Randall Hawkins; Robert Parker

1993-01-01

321

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

322

Assessment of secondary radiation and radiation protection in laser-driven proton therapy.  

PubMed

This work is a feasibility study of a radiation treatment unit with laser-driven protons based on a state-of-the-art energy selection system employing four dipole magnets in a compact shielded beamline. The secondary radiation emitted from the beamline and its energy selection system and the resulting effective dose to the patient are assessed. Further, it is evaluated whether or not such a compact system could be operated in a conventional treatment vault for clinical linear accelerators under the constraint of not exceeding the effective dose limit of 1 mSv per year to the general public outside the treatment room. The Monte Carlo code Geant4 is employed to simulate the secondary radiation generated while irradiating a hypothetical tumor. The secondary radiation inevitably generated inside the patient is taken into account as well, serving as a lower limit. The results show that the secondary radiation emanating from the shielded compact therapy system would pose a serious secondary dose contamination to the patient. This is due to the broad energy spectrum and in particular the angular distribution of the laser-driven protons, which make the investigated beamline together with the employed energy selection system quite inefficient. The secondary radiation also cannot be sufficiently absorbed in a conventional linear accelerator treatment vault to enable a clinical operation. A promising result, however, is the fact that the secondary radiation generated in the patient alone could be very well shielded by a regular treatment vault, allowing the application of more than 100 fractions of 2Gy per day with protons. It is thus theoretically possible to treat patients with protons in such treatment vaults. Nevertheless, the results show that there is a clear need for alternative more efficient energy selection solutions for laser-driven protons. PMID:25267383

Faby, Sebastian; Wilkens, Jan J

2014-09-26

323

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

324

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

325

Real-time dosimetry in external beam radiation therapy  

PubMed Central

With growing complexity in radiotherapy treatment delivery, it has become mandatory to check each and every treatment plan before implementing clinically. This process is currently administered by an independent secondary check of all treatment parameters and as a pre-treatment quality assurance (QA) check for intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy treatment plans. Although pre-treatment IMRT QA is aimed to ensure the correct dose is delivered to the patient, it does not necessarily predict the clinically relevant patient dose errors. During radiotherapy, treatment uncertainties can affect tumor control and may increase complications to surrounding normal tissues. To combat this, image guided radiotherapy is employed to help ensure the plan conditions are mimicked on the treatment machine. However, it does not provide information on actual delivered dose to the tumor volume. Knowledge of actual dose delivered during treatment aid in confirming the prescribed dose and also to replan/reassess the treatment in situations where the planned dose is not delivered as expected by the treating physician. Major accidents in radiotherapy would have been averted if real time dosimetry is incorporated as part of the routine radiotherapy procedure. Of late real-time dosimetry is becoming popular with complex treatments in radiotherapy. Real-time dosimetry can be either in the form of point doses or planar doses or projected on to a 3D image dataset to obtain volumetric dose. They either provide entrance dose or exit dose or dose inside the natural cavities of a patient. In external beam radiotherapy, there are four different established platforms whereby the delivered dose information can be obtained: (1) Collimator; (2) Patient; (3) Couch; and (4) Electronic Portal Imaging Device. Current real-time dosimetric techniques available in radiotherapy have their own advantages and disadvantages and a combination of one or more of these methods provide vital information about the actual dose delivered to radiotherapy patients. PMID:24179630

Prabhakar, Ramachandran

2013-01-01

326

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

327

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

328

Patterns of Failure after Postoperative Radiation Therapy for Endometrial Carcinoma  

PubMed Central

Purpose We tried to investigate the outcome and patterns of failure of endometrial cancer patients who were treated with surgery and postoperative radiation therapy (RT). Materials and Methods Eighty-three patients with endometrial cancer who received postoperative RT between May 1979 and August 2000 were included in this retrospective study. Forty-one patients received total abdominal hysterectomy, 41 patients received Wertheim's operation and 1 underwent vaginal hysterectomy. Pelvic lymph node dissection or pelvic lymph node sampling was done in 56 patients and peritoneal cytology was done in 35. All the patients were staged according to 1988 FIGO (International Federation of Gynecology and Obstetrics) staging system; 2 were stage IA, 23 were stage IB, 20 were stage IC, 4 were stage IIA, 5 were stage IIB, 9 were stage IIIA, 2 were stage IIIB and 18 were stage IIIC. The histologic diagnoses were adenocarcinoma in seventy-four patients (89%). The histologic grades were Grade 1, 2 and 3 in 21 (25%), 43 (52%) and 10 (12%) patients, respectively. All the patients received external beam RT (EBRT) with a median dose of 5,040 cGy (range: 4,500~5,075 cGy) to the whole pelvis. Five patients with pathologically confirmed paraaortic lymph node metastasis received 4500 cGy to the paraaortic lymph nodes. Fifteen patients received low-dose intracavitary brachytherapy after their EBRT. A total dose of 7,500~9,540 cGy (median dose: 8511) was prescribed to the vaginal surface. Results Overall, 11 patients (13%) experienced disease relapse: 4 with initial stage I or II disease and 7 with initial stage III disease. Among the 54 stage I or II patients, 1 (2%) relapsed in the pelvis only, 2 (4%) relapsed in the vagina and distant organs, and 1 (2%) relapsed in the paraaortic lymph nodes (PANs). Among the 29 stage III patients, 1 (3%) relapsed in the vagina. The most common sites of failure for the stage III patients were the peritoneum (3 patients, 10%), PANs (2 patients, 7%), and lung (2 patients, 7%). With a median follow-up period of 86 months, the overall survival (OS) and disease-free survival (DFS) rates at 5 years were 87% for both. The five-year DFS rate was 93%, 100% and 74% for the stage I, II and III patients, respectively. Three patients experienced severe radiation-related late complications: RTOG (Radiation Therapy Oncology Group) grade 3 radiation cystitis was seen in one patient, and grade 3 bowel obstruction was seen in two patients. Conclusions Postoperative RT was useful for controlling pelvic disease. The major patterns of failure for stage III patients were peritoneal seeding and distant metastasis. Selective use of whole abdominal radiotherapy or adjuvant chemotherapy may improve the therapeutic outcome of these patients. PMID:19771273

Kim, Suzy; Lee, Hyo-Pyo; Kang, Soon-Beom; Song, Yong-Sang; Park, Noh-Hyun; Ha, Sung Whan

2006-01-01

329

Hematopoietic toxicity of regional radiation therapy. Correlations for combined modality therapy with systemic chemotherapy  

SciTech Connect

Using circulating granulocyte-monocyte precursor colony-forming units in culture (CFUc) numbers as a probe along with standard blood count (CBC), the authors have quantitatively examined the hematopoietic toxicity of conventionally fractionated radiation therapy (RT) when combined with concurrent systemic chemotherapy or when used alone. Among 20 patients with limited stage small cell lung cancer receiving systemic chemotherapy with cyclophosphamide, CCNU, and methotrexate, the addition of involved field chest RT resulted in increased hematopoietic toxicity as judged by increased need for platelet transfusion (P less than 0.05) and decreased frequency of measurable CFUc (P less than 0.04). Among 22 patients receiving regional radiotherapy alone consistent hematopoietic toxicity was also observed. This toxicity, although generally of only mild to moderate clinical significance, was detected earlier and to a greater degree in patients who required radiation to larger treatment volumes, who had significant amounts of bone marrow in the port, and who had a high percentage of cardiac output flowing through the port. These data suggest that the hematopoietic toxicity of regional radiotherapy may be additive to that of concurrent systemic chemotherapy and may occur more promptly and to a greater degree when treatment volumes are larger or incorporate increased amounts of marrow volume or cardiac output.

Abrams, R.A.; Lichter, A.S.; Bromer, R.H.; Minna, J.D.; Cohen, M.H.; Deisseroth, A.B.

1985-04-01

330

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

331

The retina dose-area histogram: a metric for quantitatively comparing rival eye plaque treatment options  

PubMed Central

Purpose Episcleral plaques have a history of over a half century in the delivery of radiation therapy to intraocular tumors such as choroidal melanoma. Although the tumor control rate is high, vision-impairing complications subsequent to treatment remain an issue. Notable, late complications are radiation retinopathy and maculopathy. The obvious way to reduce the risk of radiation damage to the retina is to conform the prescribed isodose surface to the tumor base and to reduce the dose delivered to the surrounding healthy retina, especially the macula. Using a fusion of fundus photography, ultrasound and CT images, tumor size, shape and location within the eye can be accurately simulated as part of the radiation planning process. In this work an adaptation of the dose-volume histogram (DVH), the retina dose-area histogram (RDAH) is introduced as a metric to help compare rival plaque designs and conformal treatment planning options with the goal of reducing radiation retinopathy. Material and methods The RDAH is calculated by transforming a digitized fundus-photo collage of the tumor into a rasterized polar map of the retinal surface known as a retinal diagram (RD). The perimeter of the tumor base is digitized on the RD and its area computed. Area and radiation dose are calculated for every pixel in the RD. Results The areal resolution of the RDAH is a function of the pixel resolution of the raster image used to display the RD and the number of polygon edges used to digitize the perimeter of the tumor base. A practical demonstration is presented. Conclusions The RDAH provides a quantitative metric by which episcleral plaque treatment plan options may be evaluated and compared in order to confirm adequate dosimetric coverage of the tumor and margin, and to help minimize dose to the macula and retina. PMID:23634152

2013-01-01

332

Accuracy of Real-time Couch Tracking During 3-dimensional Conformal Radiation Therapy, Intensity Modulated Radiation Therapy, and Volumetric Modulated Arc Therapy for Prostate Cancer  

SciTech Connect

Purpose: To evaluate the accuracy of real-time couch tracking for prostate cancer. Methods and Materials: Intrafractional motion trajectories of 15 prostate cancer patients were the basis for this phantom study; prostate motion had been monitored with the Calypso System. An industrial robot moved a phantom along these trajectories, motion was detected via an infrared camera system, and the robotic HexaPOD couch was used for real-time counter-steering. Residual phantom motion during real-time tracking was measured with the infrared camera system. Film dosimetry was performed during delivery of 3-dimensional conformal radiation therapy (3D-CRT), step-and-shoot intensity modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT). Results: Motion of the prostate was largest in the anterior-posterior direction, with systematic ( N-Ary-Summation ) and random ({sigma}) errors of 2.3 mm and 2.9 mm, respectively; the prostate was outside a threshold of 5 mm (3D vector) for 25.0%{+-}19.8% of treatment time. Real-time tracking reduced prostate motion to N-Ary-Summation =0.01 mm and {sigma} = 0.55 mm in the anterior-posterior direction; the prostate remained within a 1-mm and 5-mm threshold for 93.9%{+-}4.6% and 99.7%{+-}0.4% of the time, respectively. Without real-time tracking, pass rates based on a {gamma} index of 2%/2 mm in film dosimetry ranged between 66% and 72% for 3D-CRT, IMRT, and VMAT, on average. Real-time tracking increased pass rates to minimum 98% on average for 3D-CRT, IMRT, and VMAT. Conclusions: Real-time couch tracking resulted in submillimeter accuracy for prostate cancer, which transferred into high dosimetric accuracy independently of whether 3D-CRT, IMRT, or VMAT was used.

Wilbert, Juergen; Baier, Kurt [Department of Radiation Oncology, University of Wuerzburg, Wuerzburg (Germany)] [Department of Radiation Oncology, University of Wuerzburg, Wuerzburg (Germany); Hermann, Christian [Department of Computer Sciences VII, Robotics, and Telematics, University of Wuerzburg, Wuerzburg (Germany)] [Department of Computer Sciences VII, Robotics, and Telematics, University of Wuerzburg, Wuerzburg (Germany); Flentje, Michael [Department of Radiation Oncology, University of Wuerzburg, Wuerzburg (Germany)] [Department of Radiation Oncology, University of Wuerzburg, Wuerzburg (Germany); Guckenberger, Matthias, E-mail: guckenberger_m@klinik.uni-wuerzburg.de [Department of Radiation Oncology, University of Wuerzburg, Wuerzburg (Germany)] [Department of Radiation Oncology, University of Wuerzburg, Wuerzburg (Germany)

2013-01-01

333

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

334

Barriers to accessing radiation therapy in Canada: a systematic review  

PubMed Central

Introduction Radiation therapy (RT) is effective treatment for curing and palliating cancer, yet concern exists that not all Canadians for whom RT is indicated receive it. Many factors may contribute to suboptimal use of RT. A review of recent Canadian literature was undertaken to identify such barriers. Methods MEDLINE, CINAHL, and EMBase databases were used to search keywords relating to barriers to accessing or utilizing RT in Canada. Collected abstracts were reviewed independently. Barriers identified in relevant articles were categorized as relating to the health systems, patient socio-demographic, patient factors, or provider factors contexts and thematic analysis performed for each context. Results 535 unique abstracts were collected. 75 met inclusion criteria. 46 (61.3%) addressed multiple themes. The most cited barriers to accessing RT when indicated were patient age (n?=?26, 34.7%), distance to treatment centre (n?=?23, 30.7%), wait times (n?=?22, 29.3%), and lack of physician understanding about the use of RT (n?=?16, 21.6%). Conclusions Barriers to RT are reported in many areas. The role of provider factors and the lack of attention to patient fears and mistrust as potential barriers were unexpected findings demanding further attention. Solutions should be sought to overcome identified barriers facilitating more effective cancer care for Canadians. PMID:23062109

2012-01-01

335

ACOUSTIC RADIATION FORCE FOR VASCULAR CELL THERAPY: IN VITRO VALIDATION  

PubMed Central

Cell-based therapeutic approaches are attractive for the restoration of the protective endothelial layer in arteries affected by atherosclerosis or following angioplasty and stenting. We have recently demonstrated a novel technique for the delivery of mesenchymal stem cells (MSCs) that are surface-coated with cationic lipid microbubbles (MBs) and displaced by acoustic radiation force (ARF) to a site of arterial injury. The objective of this study was to characterize ultrasound parameters for effective acoustic-based delivery of cell therapy. In vitro experiments were performed in a vascular flow phantom where MB-tagged MSCs were delivered towards the phantom wall using ARF generated with an intravascular ultrasound catheter. The translation motion velocity and adhesion of the MB-cell complexes were analyzed. Experimental data indicated that MSC radial velocity and adhesion to the vessel phantom increased with the time-averaged ultrasound intensity up to 1.65 W/cm2, after which no further significant adhesion was observed. Temperature increase from baseline near the catheter was 5.5 ±0.8°C with this setting. Using higher time-averaged ultrasound intensities may not significantly benefit the adhesion of MB-cell complexes to the target vessel wall (p=NS), but could cause undesirable biological effects such as heating to the MB-cell complexes and surrounding tissue. For the highest time-averaged ultrasound intensity of 6.60 W/cm2, the temperature increase was 11.6 ±1.3°C. PMID:22975034

Kaya, Mehmet; Toma, Catalin; Wang, Jianjun; Grata, Michelle; Fu, Huili; Villanueva, Flordeliza S.; Chen, Xucai

2012-01-01

336

Objective Assessment of Image Quality VI: Imaging in Radiation Therapy  

PubMed Central

Earlier work on Objective Assessment of Image Quality (OAIQ) focused largely on estimation or classification tasks in which the desired outcome of imaging is accurate diagnosis. This paper develops a general framework for assessing imaging quality on the basis of therapeutic outcomes rather than diagnostic performance. By analogy to Receiver Operating Characteristic (ROC) curves and their variants as used in diagnostic OAIQ, the method proposed here utilizes the Therapy Operating Characteristic or TOC curves, which are plots of the probability of tumor control vs. the probability of normal-tissue complications as the overall dose level of a radiotherapy treatment is varied. The proposed figure of merit is the area under the TOC curve, denoted AUTOC. This paper reviews an earlier exposition of the theory of TOC and AUTOC, which was specific to the assessment of image-segmentation algorithms, and extends it to other applications of imaging in external-beam radiation treatment as well as in treatment with internal radioactive sources. For each application, a methodology for computing the TOC is presented. A key difference between ROC and TOC is that the latter can be defined for a single patient rather than a population of patients. PMID:24200954

Barrett, Harrison H.; Kupinski, Matthew A.; Müeller, Stefan; Halpern, Howard J.; Morris, John C.; Dwyer, Roisin

2015-01-01

337

High resolution optical calorimetry for synchrotron microbeam radiation therapy  

NASA Astrophysics Data System (ADS)

We propose the application of optical calorimetry to measure the peak to valley ratio for synchrotron microbeam radiation therapy (MRT). We use a modified Schlieren approach known as reference image topography (RIT) which enables one to obtain a map of the rate of change of the refractive index in a water bath from which the absorbed dose can be determined with sufficient spatial accuracy to determine the peak to valley ratio. We modelled the calorimetric properties of X-rays using a heated wire in a water bath. Our RIT system comprised a light source, a textured reference object and a camera and lens combination. We measured temperature contours and showed a plume rising from the heated wire. The total temperature change in water was 12 degrees C, 500 times greater than the calculated change from a 1 ms exposure on a synchrotron. At 1.0 ms, thermal diffusion will be the major cause of uncertainty in determining the peak to valley ratio, and we calculate thermal diffusion will reduce the measured peak to valley ratio to 76% of its initial value, but the individual microbeams will still resolve. We demonstrate proof of concept for measuring X-ray dose using a modified RIT method.

Ackerly, T.; Crosbie, J. C.; Fouras, A.; Sheard, G. J.; Higgins, S.; Lewis, R. A.

2011-03-01

338

Techniques for the Enhancement of Optimization Schemes in Radiation Therapy  

NASA Astrophysics Data System (ADS)

With the advent of intensity modulated radiation therapy (IMRT), the process of generating a radiotherapy treatment plan has become a complex and time consuming process due to an increase in the number of variables which must be optimized. These large variable sets, in the form of beamlet fluence dose distributions, must be weight-optimized in order to produce a radiotherapy treatment plan that homogeneously delivers the prescribed dose to the tumor volume and delivers an acceptable amount of dose to normal tissue. Therefore the ability of optimization algorithms to generate radiotherapy plans that conform to these parameters and to produce these plans in a clinically-timely manner has become paramount. In addition, the introduction of multi-criteria optimization increases the number of optimized plans which need to be generated further increasing optimization time. This increase in optimization complexity can be addressed in two different ways: current optimization algorithms can be made more efficient by reducing the number of mathematical operations they require; and the possibility of applying a new optimization technology, such as a quantum annealing algorithm, may be explored. I have investigated reducing the number of mathematical operation required in optimization by sampling precomputed dose matrices. The results of this study are presented and indicate that it is a promising methodology for IMRT optimization. Additionally, the results from the application of a quantum annealing algorithm based on a novel quantum computing system to the IMRT optimization problem are discussed.

Spaans, Jason D.

339

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

340

Objective assessment of image quality VI: imaging in radiation therapy  

NASA Astrophysics Data System (ADS)

Earlier work on objective assessment of image quality (OAIQ) focused largely on estimation or classification tasks in which the desired outcome of imaging is accurate diagnosis. This paper develops a general framework for assessing imaging quality on the basis of therapeutic outcomes rather than diagnostic performance. By analogy to receiver operating characteristic (ROC) curves and their variants as used in diagnostic OAIQ, the method proposed here utilizes the therapy operating characteristic or TOC curves, which are plots of the probability of tumor control versus the probability of normal-tissue complications as the overall dose level of a radiotherapy treatment is varied. The proposed figure of merit is the area under the TOC curve, denoted AUTOC. This paper reviews an earlier exposition of the theory of TOC and AUTOC, which was specific to the assessment of image-segmentation algorithms, and extends it to other applications of imaging in external-beam radiation treatment as well as in treatment with internal radioactive sources. For each application, a methodology for computing the TOC is presented. A key difference between ROC and TOC is that the latter can be defined for a single patient rather than a population of patients.

Barrett, Harrison H.; Kupinski, Matthew A.; Müeller, Stefan; Halpern, Howard J.; Morris, John C., III; Dwyer, Roisin

2013-11-01

341

Radiation pneumonitis in breast cancer patients treated with taxanes: does sequential radiation therapy lower the risk?  

PubMed

Taxanes are now routinely used in conjunction with radiation therapy (RT) as adjuvant therapy for breast cancer. Recent publications have reported several cases of radiation pneumonitis (RP) in patients receiving RT and taxane chemotherapy, thus raising concern as to the safety of this combination. To decrease the potential risk of RP, we sequenced RT after taxane chemotherapy with a target interval of 3-4 weeks in two consecutive institutional breast protocols. Forty patients were treated on two adjuvant systemic protocols consisting of modified radical mastectomy (n = 9) or breast-conserving surgery (n = 31), followed by adjuvant doxorubicin, cyclophosphamide, and a sequential taxane (ACT), followed by RT. All patients had either node-positive or high-risk node-negative breast cancer and were treated between October 2000 and September 2002. Postmastectomy, a median dose of 5040 cGy was delivered to the chest wall. After breast-conserving surgery, a median dose of 4680 cGy was delivered to the breast plus a 1400 cGy boost to the surgical cavity. Information regarding RP was gathered retrospectively by reviewing patient records. With a median follow-up of 28 months (range 6-42 months), no cases of clinical RP were identified and no local failures had occurred. The median time interval for all patients between the completion of chemotherapy and the initiation of RT was 34 days (range 5-70 days). At the latest follow-up, 2 patients were diagnosed with metastatic disease and 38 patients were without evidence of disease. Sequencing of RT after taxane therapy with a target interval of 3-4 weeks does not appear to result in increased pulmonary toxicity and is associated with good local control. PMID:16174151

Beal, Kathryn; Hudis, Clifford; Norton, Larry; Wagman, Raquel; McCormick, Beryl

2005-01-01

342

Radiation Therapy Is Associated With Improved Survival in the Adjuvant and Definitive Treatment of Intrahepatic Cholangiocarcinoma  

SciTech Connect

Purpose: Intrahepatic cholangiocarcinomas (IHC) are rare tumors for which large randomized studies regarding the use of radiation are not available. The purpose of this study was to examine the role of adjuvant and definitive radiation therapy in the treatment of IHC in a large group of patients. Methods and Materials: This is a retrospective analysis of 3,839 patients with IHC collected from the Surveillance, Epidemiology, and End Results (SEER) database. The primary endpoint was overall survival (OS). Results: Patients received either surgery alone (25%), radiation therapy alone (10%), surgery and adjuvant radiation therapy (7%) or no treatment (58%). The median age of the patient population was 73 years (range, 22-102 years); 52% of patients were male and 81% were Caucasian. Median OS was 11 (95% confidence interval [CI], 9-13), 6 (95% CI, 5-6), 7 (95% CI, 6-8), and 3 months for surgery and adjuvant radiation therapy, sugery alone, radiation therapy alone, and no treatment, respectively. The OS was significantly different between surgery alone and surgery and adjuvant radiation therapy (p = 0.014) and radiation therapy alone and no treatment (p < 0.0001). Use of surgery and adjuvant radiation therapy conferred the greatest benefit on OS (HR = 0.40; 95% CI, 0.34-0.47), followed by surgery alone (hazard ratio [HR], 0.49; 95% CI, 0.44-0.54) and radiation therapy alone (HR, 0.68; 95% CI, 0.59-0.77) compared with no treatment, on multivariate analysis. Propensity score adjusted hazard ratios (controlling for age, race/ethnicity, stage, and year of diagnosis) were also significant (surgery and adjuvant radiation therapy vs. surgery alone (HR, 0.82; 95% CI, 0.70-0.96); radiation therapy alone vs. no treatment (HR, 0.67; 95% CI, 0.58-0.76)). Conclusions: The study results suggest that adjuvant and definitive radiation treatment prolong survival, although cure rates remain low. Future studies should evaluate the addition of chemotherapy and biologics to the treatment of IHC.

Shinohara, Eric T. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States)], E-mail: Shinohara@xrt.upenn.edu; Mitra, Nandita; Guo Mengye [Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA (United States); Metz, James M. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States)

2008-12-01

343

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

PubMed

To develop a quality assurance (QA) of XVI cone beam system (XVIcbs) for its optimal imaging-guided radiotherapy (IGRT) implementation, and to construe prostate tumor margin required for intensity-modulated radiation therapy (IMRT) if IGRT is unavailable. XVIcbs spatial accuracy was explored with a humanoid phantom; isodose conformity to lesion target with a rice phantom housing a soap as target; image resolution with a diagnostic phantom; and exposure validation with a Radcal ion chamber. To optimize XVIcbs, rotation flexmap on coincidency between gantry rotational axis and that of XVI cone beam scan was investigated. Theoretic correlation to image quality of XVIcbs rotational axis stability was elaborately studied. Comprehensive QA of IGRT using XVIcbs has initially been explored and then implemented on our general IMRT treatments, and on special IMRT radiotherapies such as head and neck (H and N), stereotactic radiation therapy (SRT), stereotactic radiosurgery (SRS), and stereotactic body radiotherapy (SBRT). Fifteen examples of prostate setup accounted for 350 IGRT cone beam system were analyzed. IGRT accuracy results were in agreement ± 1 mm. Flexmap 0.25 mm met the manufacturer's specification. Films confirmed isodose coincidence with target (soap) via XVIcbs, otherwise not. Superficial doses were measured from 7.2-2.5 cGy for anatomic diameters 15-33 cm, respectively. Image quality was susceptible to rotational stability or patient movement. IGRT using XVIcbs on general IMRT treatments such as prostate, SRT, SRS, and SBRT for setup accuracy were verified; and subsequently coordinate shifts corrections were recorded. The 350 prostate IGRT coordinate shifts modeled to Gaussian distributions show central peaks deviated off the isocenter by 0.6 ± 3.0 mm, 0.5 ± 4.5 mm in the X(RL)- and Z(SI)-coordinates, respectively; and 2.0 ± 3.0 mm in the Y(AP)-coordinate as a result of belly and bladder capacity variations. Sixty-eight percent of confidence was within ± 4.5 mm coordinates shifting. IGRT using XVIcbs is critical to IMRT for prostate and H and N, especially SRT, SRS, and SBRT. To optimize this modality of IGRT, a vigilant QA program is indispensable. Prostate IGRT reveals treatment accuracy as subject to coordinates' adjustments; otherwise a 4.5-mm margin is required to allow for full dose coverage of the clinical target volume, notwithstanding toxicity to normal tissues. PMID:22417899

Tsai, Jen-San; Micaily, Bizhan; Miyamoto, Curtis

2012-01-01

344

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

345

Intradural extramedullary tuberculoma mimicking en plaque meningioma.  

PubMed

A 24-year-old man with tuberculosis meningitis developed acute paraplegia and sensory disturbances 5 weeks after receiving conventional antituberculous therapy. Magnetic resonance imaging revealed an intradural extramedullary long segmental mass mimicking en plaque meningioma at the T2-T6 vertebrae levels. Prompt surgical decompression was performed. A histology examination of the mass revealed a tuberculoma. After surgery, the patient showed improved motor power and a normal bladder function. Intradural extramedullary tuberculoma of the spinal cord is rare complication of tuberculosis meningitis, which can occur as a response to conventional antituberculous therapy. PMID:21119945

Shim, Dae Moo; Oh, Sung Kyun; Kim, Tae Kyun; Chae, Soo Uk

2010-12-01

346

Intradural Extramedullary Tuberculoma Mimicking En Plaque Meningioma  

PubMed Central

A 24-year-old man with tuberculosis meningitis developed acute paraplegia and sensory disturbances 5 weeks after receiving conventional antituberculous therapy. Magnetic resonance imaging revealed an intradural extramedullary long segmental mass mimicking en plaque meningioma at the T2-T6 vertebrae levels. Prompt surgical decompression was performed. A histology examination of the mass revealed a tuberculoma. After surgery, the patient showed improved motor power and a normal bladder function. Intradural extramedullary tuberculoma of the spinal cord is rare complication of tuberculosis meningitis, which can occur as a response to conventional antituberculous therapy. PMID:21119945

Shim, Dae Moo; Kim, Tae Kyun; Chae, Soo Uk

2010-01-01

347

Aortic Arch Plaques and Risk of Recurrent Stroke and Death  

PubMed Central

Background Aortic arch plaques are a risk factor for ischemic stroke. Although the stroke mechanism is conceivably thromboembolic, no randomized studies have evaluated the efficacy of antithrombotic therapies in preventing recurrent events. Methods and Results The relationship between arch plaques and recurrent events was studied in 516 patients with ischemic stroke, double–blindly randomized to treatment with warfarin or aspirin as part of the Patent Foramen Ovale in Cryptogenic Stroke Study (PICSS), based on the Warfarin-Aspirin Recurrent Stroke Study (WARSS). Plaque thickness and morphology was evaluated by transesophageal echocardiography. End-points were recurrent ischemic stroke or death over a 2-year follow-up. Large plaques (?4mm) were present in 19.6% of patients, large complex plaques (those with ulcerations or mobile components) in 8.5 %. During follow-up, large plaques were associated with a significantly increased risk of events (adjusted Hazard Ratio 2.12, 95% Confidence Interval 1.04-4.32), especially those with complex morphology (HR 2.55, CI 1.10-5.89). The risk was highest among cryptogenic stroke patients, both for large plaques (HR 6.42, CI 1.62-25.46) and large-complex plaques (HR 9.50, CI 1.92-47.10). Event rates were similar in the warfarin and aspirin groups in the overall study population (16.4% vs. 15.8%; p=0.43). Conclusions In patients with stroke, and especially cryptogenic stroke, large aortic plaques remain associated with an increased risk of recurrent stroke and death at two years despite treatment with warfarin or aspirin. Complex plaque morphology confers a slight additional increase in risk. PMID:19380621

Di Tullio, Marco R.; Russo, Cesare; Jin, Zhezhen; Sacco, Ralph L.; Mohr, J.P.; Homma, Shunichi

2010-01-01

348

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

349

Identification of Amyloid Plaques in Retinas from Alzheimer’s Patients and Noninvasive In Vivo Optical Imaging of Retinal Plaques in a Mouse Model  

PubMed Central

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 portrays 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 APPSWE/PS1?E9 transgenic mice (AD-Tg; n=18) and 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.

2010-01-01

350

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

351

Ovarian cancer: contribution of radiation therapy to patient management: Erskine Memorial Lecture, 1983  

SciTech Connect

Ovarian cancer may be treated with radiation therapy, surgery, chemotherapy, or a combination. To evaluate the contribution of radiation therapy to patient management the cure rate must be estimated; data are presented suggesting that the 5-year survival rate provides a reasonable estimate of the cure rate. A study of patients treated since 1971 showed that stage and postoperative residuum could be used to divide patients into two subgroups, a poor prognosis group and a good prognosis group; a multifactorial grouping of patients in the good prognosis group who were treated postoperatively with radiation therapy only was further able to divide patients into low-risk, intermediate-risk, and high-risk groups. Studies of radiation therapy for different subgroups are discussed; abdominopelvic irradiation has been shown to improve survival for approximately one-third of patients with cancer of the ovary.

Bush, R.S.

1984-10-01

352

Ohio State U study finds that experience counts with radiation therapy for head and neck cancer  

Cancer.gov

Radiation therapy for head and neck cancer is highly complex, and a new study published in the Journal of Clinical Oncology with an accompanying editorial suggests that medical centers with more experience centers have better patient outcomes.

353

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

Code of Federal Regulations, 2014 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5050 Medical charged-particle radiation therapy system. (a)...

2014-04-01

354

21 CFR 892.5710 - Radiation therapy beam-shaping block.  

Code of Federal Regulations, 2011 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification....

2011-04-01

355

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

Code of Federal Regulations, 2012 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5050 Medical charged-particle radiation therapy system. (a)...

2012-04-01

356

21 CFR 892.5770 - Powered radiation therapy patient support assembly.  

Code of Federal Regulations, 2010 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5770 Powered radiation therapy patient support assembly. (a)...

2010-04-01

357

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

Code of Federal Regulations, 2011 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5050 Medical charged-particle radiation therapy system. (a)...

2011-04-01

358

21 CFR 892.5770 - Powered radiation therapy patient support assembly.  

Code of Federal Regulations, 2014 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5770 Powered radiation therapy patient support assembly. (a)...

2014-04-01

359

21 CFR 892.5770 - Powered radiation therapy patient support assembly.  

Code of Federal Regulations, 2011 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5770 Powered radiation therapy patient support assembly. (a)...

2011-04-01

360

21 CFR 892.5710 - Radiation therapy beam-shaping block.  

Code of Federal Regulations, 2012 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification....

2012-04-01

361

21 CFR 892.5710 - Radiation therapy beam-shaping block.  

Code of Federal Regulations, 2013 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification....

2013-04-01

362

21 CFR 892.5710 - Radiation therapy beam-shaping block.  

Code of Federal Regulations, 2010 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification....

2010-04-01

363

21 CFR 892.5710 - Radiation therapy beam-shaping block.  

Code of Federal Regulations, 2014 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification....

2014-04-01

364

21 CFR 892.5770 - Powered radiation therapy patient support assembly.  

Code of Federal Regulations, 2012 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5770 Powered radiation therapy patient support assembly. (a)...

2012-04-01

365

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

Code of Federal Regulations, 2013 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5050 Medical charged-particle radiation therapy system. (a)...

2013-04-01

366

21 CFR 892.5770 - Powered radiation therapy patient support assembly.  

Code of Federal Regulations, 2013 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5770 Powered radiation therapy patient support assembly. (a)...

2013-04-01

367

The Impact of Lateral Electron Disequilibrium on Stereotactic Body Radiation Therapy of Lung Cancer.  

E-print Network

??Stereotactic Body Radiation Therapy (SBRT) is an effective treatment option for patients with inoperable early-stage lung cancer. SBRT uses online image-guidance technology [e.g. cone-beam CT… (more)

Disher, Brandon

2013-01-01

368

Apoptosis occurs in lymphoma cells but not in hepatoma cells following ionizing radiation and photodynamic therapy  

Microsoft Academic Search

The aim of this study was to determine the relative role of apoptosis in photodynamically-induced cytotoxicity or radiation-induced cytotoxicity for hepatoma and lymphoma cells. Human hepatoma cells and mouse lymphoma cells were treated with either photodynamic therapy (PDT) or ionizing radiation. Dosimetry studies of immediate cell death following photodynamic therapy in the hepatoma cell line demonstrated second-order kinetics, similar to

Mark A. Laukka; Kenneth K. Wang; James A. Bonner

1994-01-01

369

Comparative analysis of 60Co intensity-modulated radiation therapy  

NASA Astrophysics Data System (ADS)

In this study, we perform a scientific comparative analysis of using 60Co beams in intensity-modulated radiation therapy (IMRT). In particular, we evaluate the treatment plan quality obtained with (i) 6 MV, 18 MV and 60Co IMRT; (ii) different numbers of static multileaf collimator (MLC) delivered 60Co beams and (iii) a helical tomotherapy 60Co 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 60Co 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 60Co 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 60Co beam geometry achieved similar plan quality as static plans with 11 equidistant 60Co beams. Furthermore, 18 MV plans were initially found not to provide the same target coverage as 6 MV and 60Co 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 60Co 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 60Co 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. This work was supported by the National Science Foundation under grant no. DMI-0457394 and the National Cancer Institute under grant no. R01 CA100636.

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

2008-06-01

370

Commissioning of Peacock System for intensity-modulated radiation therapy.  

PubMed

The Peacock System was introduced to perform tomographic intensity-modulated radiation therapy (IMRT). Commissioning of the Peacock System included the alignment of the multileaf intensity-modulating collimator (MIMiC) to the beam axis, the alignment of the RTA device for immobilization, and checking the integrity of the CRANE for indexing the treatment couch. In addition, the secondary jaw settings, couch step size, and transmission through the leaves were determined. The dosimetric data required for the CORVUS planning system were divided into linear accelerator-specific and MIMiC-specific. The linear accelerator-specific dosimetric data were relative output in air, relative output in phantom, percent depth dose for a range of field sizes, and diagonal dose profiles for a large field size. The MIMiC-specific dosimetric data were the in-plane and cross-plane dose profiles of a small and a large field size to derive the penumbra fit. For each treatment unit, the Beam Utility software requires the data be entered into the CORVUS planning system in modular forms. These modules were treatment unit information, angle definition, configuration, gantry and couch angles range, dosimetry, results, and verification plans. After the appropriate machine data were entered, CORVUS created a dose model. The dose model was used to create known simple dose distribution for evaluation using the verification tools of the CORVUS. The planned doses for phantoms were confirmed using an ion chamber for point dose measurement and film for relative dose measurement. The planning system calibration factor was initially set at 1.0 and will be changed after data on clinical cases are acquired. The treatment unit was released for clinical use after the approval icon was checked in the verification plans module. PMID:11417508

Saw, C B; Ayyangar, K M; Thompson, R B; Zhen, W; Enke, C A

2001-01-01

371

Clinical Outcomes of Postmastectomy Radiation Therapy After Immediate Breast Reconstruction  

SciTech Connect

Purpose: To determine the long-term complication rates and cosmetic results for patients undergoing postmastectomy radiation therapy (PMRT) after immediate reconstruction (IR). Methods and Materials: Between January 1998 and December 2005, 92 patients underwent modified radical mastectomy, IR, and PMRT in our practice. A total of 69 patients underwent tissue expander and implant reconstruction (TE/I), and 23 underwent autologous tissue reconstruction (ATR). Follow-up regarding complications and cosmesis was obtained for all 92 patients. Complications were scored as follows: Grade 1, no discomfort; Grade 2, discomfort affecting activities of daily living; Grade 3, surgical intervention or intravenous antibiotics required; and Grade 4, removal or replacement of the reconstruction. Cosmesis was rated as either acceptable or unacceptable to the patient. Both complications and cosmesis were correlated with treatment- and patient-related factors. Results: Median follow-up for all patients was 38 months. The overall rate of severe complications (Grade 3-4) was 25%. The overall rate of poor functional results (Grade 2-4) was 43.4%. When analyzed as a function of type of reconstruction, the rate of Grade 3 to 4 complications was 33.3% for TE/I vs. 0% for ATR (p = 0.001). The rate of Grade 2 to 4 complications was 55% for TE/I vs. 8.7% for ATR (p < 0.001). Acceptable cosmesis was reported in 51% of TE/I patients vs. 82.6% of ATR patients (p = 0.007). No other treatment or patient-related factors had a significant impact on either complications or cosmesis. Conclusion: In patients undergoing PMRT after IR, ATR is associated with fewer long-term complications and better cosmetic results than TE/I.

Jhaveri, Jigna Desai [Department of Radiation Oncology, Long Island Radiation Therapy, Garden City, NY (United States)], E-mail: jhaveri.jigna@gmail.com; Rush, Stephen C. [Department of Radiation Oncology, Long Island Radiation Therapy, Garden City, NY (United States); Kostroff, Karen [Department of Surgery, Long Island Jewish Hospital, New Hyde Park, NY (United States); Derisi, Dwight [Department of Surgery, North Shore University Hospital, Manhasset, NY (United States); Farber, Leonard A. [Department of Radiation Oncology, Long Island Radiation Therapy, Garden City, NY (United States); Maurer, Virginia E. [Department of Surgery, Winthrop University Hospital, Mineola, NY (United States); Bosworth, Jay L. [Department of Radiation Oncology, Long Island Radiation Therapy, Garden City, NY (United States)

2008-11-01

372

Ipilimumab and whole brain radiation therapy for melanoma brain metastases.  

PubMed

Brain metastases (BM) frequently develop in patients with melanoma and are associated with a poor prognosis. Whole brain radiation therapy (WBRT) is a standard intervention for intracranial disease, particularly in patients with multiple BM. Ipilimumab improves survival in patients with advanced melanoma. The purpose of this study is to investigate the safety and efficacy of concurrent WBRT and ipilimumab. A retrospective analysis was conducted of 13 consecutive patients treated with WBRT within 30 days of ipilimumab administration. Radiographic response, as measured by serial magnetic resonance imaging scans post-treatment, was graded by modified World Health Organization (mWHO) and immune-related response criteria (irRC) in the 9 patients with follow-up imaging. Treatment-related toxicity was prospectively assessed during treatment. Four of nine patients (44 %) experienced partial response or stable central nervous system (CNS) disease as measured by mWHO criteria. This number increased to 5 patients (56 %) when irRC criteria were used. Rates of treatment-related neurologic toxicity were low with only one patient experiencing grade 3-4 neurologic toxicity. There was a high rate of intratumoral hemorrhage in this patient population, with 10 of 10 patients with post-treatment imaging demonstrating new or increased intratumoral bleeding after WBRT. This retrospective study demonstrates that the primary pattern of CNS response to WBRT and ipilimumab is stable disease and not regression of BM. Furthermore, while the combination of WBRT and ipilimumab may offer promising efficacy, prospective studies are needed to further assess efficacy and toxicity. PMID:25273687

Gerber, Naamit K; Young, Robert J; Barker, Christopher A; Wolchok, Jedd D; Chan, Timothy A; Yamada, Yoshiya; Friguglietti, Leigh; Beal, Kathryn

2014-10-01

373

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

374

Involved-Field Radiation Therapy for Locoregionally Recurrent Ovarian Cancer  

PubMed Central

Objective To evaluate the effectiveness of definitive involved-field radiation therapy (IFRT) for selected patients with locoregionally-recurrent ovarian cancer. Methods We retrospectively reviewed records of 102 epithelial ovarian cancer patients treated with definitive IFRT (?45 Gy). IFRT was directed to localized nodal (49%) and extranodal (51%) recurrences. Results The median time from diagnosis to IFRT was 36 months (range, 1–311), and the median follow-up after IFRT was 37 months (range, 1–123). Patients received a median of three chemotherapy courses before IFRT (range, 0–9). Five-year overall (OS) and progression-free survival (PFS) rates after IFRT were 40% and 24% respectively; the 5-year in-field disease control rate was 71%. Thirty-five patients (35%) had no evidence of disease at a median of 38 months after IFRT (range, 7–122), including 25 continuously without disease for a median of 61 months (range, 17–122) and 10 with salvage treatment following disease recurrence, disease-free for a median of 39 months after salvage treatment (range, 7–92). Eight clear cell carcinoma patients had higher 5-year OS (88% versus 37%; p=0.05) and PFS (75% versus 20%; p=0.01) rates than other patients. Patients sensitive to initial platinum chemotherapy had a higher 5-year OS rate than platinum-resistant patients (43% versus 27%, p=0.03). Patients who required chemotherapy for recurrence after IFRT often benefitted from longer chemotherapy-free intervals after than before IFRT. Conclusions Definitive IFRT can yield excellent local control, protracted disease-free intervals, and even cures in carefully selected patients. RT should be considered a tool in the curative management of locoregionally-recurrent ovarian cancer. PMID:23648467

Brown, Aaron P.; Jhingran, Anuja; Klopp, Ann H.; Schmeler, Kathleen M.; Ramirez, Pedro T.; Eifel, Patricia J.

2015-01-01

375

Radiation therapy alone in the treatment of carcinoma of the uterine cervix: a 20-year experience  

Microsoft Academic Search

A retrospective analysis is reported on the results of irradiation alone in the treatment of 970 patients with histologically proven invasive carcinoma of the uterine cervix. The development of the radiation therapy techniques, survival, pelvic tumor control, and major sequelae of therapy are described in detail. The tumor-free 5-year survival rate was 100% in 29 patients with stage IA, 85%

Carlos A. Perez; H. Marvin Camel; Robert R. Kuske; Ming-Shian Kao; Andrew Galakatos; Mary Ann Hederman; William E. Powers

1986-01-01

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  

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

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  

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

378

Suppressed monocyte recruitment drives macrophage removal from atherosclerotic plaques of Apoe–/– mice during disease regression  

PubMed Central

Experimental models of atherosclerosis suggest that recruitment of monocytes into plaques drives the progression of this chronic inflammatory condition. Cholesterol-lowering therapy leads to plaque stabilization or regression in human atherosclerosis, characterized by reduced macrophage content, but the mechanisms that underlie this reduction are incompletely understood. Mice lacking the gene Apoe (Apoe–/– mice) have high levels of cholesterol and spontaneously develop atherosclerotic lesions. Here, we treated Apoe–/– mice with apoE-encoding adenoviral vectors that induce plaque regression, and investigated whether macrophage removal from plaques during this regression resulted from quantitative alterations in the ability of monocytes to either enter or exit plaques. Within 2 days after apoE complementation, plasma cholesterol was normalized to wild-type levels, and HDL levels were increased 4-fold. Oil red O staining and quantitative mass spectroscopy revealed that esterified cholesterol content was markedly reduced. Plaque macrophage content decreased gradually and was 72% lower than baseline 4 weeks after apoE complementation. Importantly, this reduction in macrophages did not involve migratory egress from plaques or CCR7, a mediator of leukocyte emigration. Instead, marked suppression of monocyte recruitment coupled with a stable rate of apoptosis accounted for loss of plaque macrophages. These data suggest that therapies to inhibit monocyte recruitment to plaques may constitute a more viable strategy to reduce plaque macrophage burden than attempts to promote migratory egress. PMID:21505265

Potteaux, Stephane; Gautier, Emmanuel L.; Hutchison, Susan B.; van Rooijen, Nico; Rader, Daniel J.; Thomas, Michael J.; Sorci-Thomas, Mary G.; Randolph, Gwendalyn J.

2011-01-01

379

Intensity-Modulated Radiation Therapy With or Without Chemotherapy for Nasopharyngeal Carcinoma: Radiation Therapy Oncology Group Phase II Trial 0225  

PubMed Central

Purpose To investigate the feasibility of intensity-modulated radiation therapy (IMRT) with or without chemotherapy, and to assess toxicities, failure patterns, and survivals in patients with nasopharyngeal carcinoma (NPC). Patients and Methods Radiation consisted of 70 Gy given to the planning target volumes of primary tumor plus any N+ disease and 59.4 Gy given to subclinical disease, delivered over 33 treatment days. Patients with stage T2b or greater or with N+ disease also received concurrent cisplatin (100 mg/m2) on days 1, 22, and 43 followed by adjuvant cisplatin (80 mg/m2) on day 1; fluorouracil (1,000 mg/m2/d) on days 1 through 4 administered every 4 weeks for three cycles. Tumor, clinical status, and acute/late toxicities were assessed. The primary objective was to test the transportability of IMRT to a multi-institutional setting. Results Between February 2003 and November 2005, 68 patients with stages I through IVB NPC (of which 93.8% were WHO types 2 and 3) were enrolled. Prescribed IMRT (target delineation) was given to 83.8%, whereas 64.9% received chemotherapy per protocol. The estimated 2-year local progression-free (PF), regional PF, locoregional PF, and distant metastasis–free rates were 92.6%, 90.8%, 89.3%, and 84.7%, respectively. The estimated 2-year PF and overall survivals were 72.7% and 80.2%, respectively. Acute grade 4 mucositis occurred in 4.4%, and the worst late grade 3 toxicities were as follows: esophagus, 4.7%; mucous membranes, 3.1%; and xerostomia, 3.1%. The rate of grade 2 xerostomia at 1 year from start of IMRT was 13.5%. Only two patients complained of grade 3 xerostomia, and none had grade 4 xerostomia. Conclusion It was feasible to transport IMRT with or without chemotherapy in the treatment of NPC to a multi-institutional setting with 90% LRPF rate reproducing excellent reports from single institutions. Minimal grade 3 and lack of grade 4 xerostomia were encouraging. PMID:19564532

Lee, Nancy; Harris, Jonathan; Garden, Adam S.; Straube, William; Glisson, Bonnie; Xia, Ping; Bosch, Walter; Morrison, William H.; Quivey, Jeanne; Thorstad, Wade; Jones, Christopher; Ang, K. Kian

2009-01-01

380

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

381

Reirradiation After Radical Radiation Therapy: A Survey of Patterns of Practice Among Canadian Radiation Oncologists  

SciTech Connect

Purpose: The objective of this study was to survey the use of reirradiation (Re-RT) for in-field failures after previous radical radiation treatment (RT) among Canadian radiation oncologists (ROs). Methods and Materials: An electronic survey was sent to 271 ROs in Canada. The completed surveys were received electronically via e-mail and the data were analyzed using SAS 9.1.3 software. Results: A total of 183 ROs (67.5%) completed and returned the survey. The majority of the respondents were involved in the practice of either breast (48%) or genitourinary (43%) tumor sites. A total of 49% of the participants were interested in using Re-RT for the management of in-field recurrences. The goals of the therapy would be improvement of quality of life (99%), locoregional control (80%), or cure (32%). Most of the physicians believed that patients should have a minimum Karnofsky performance status of 50 or Eastern Cooperative Oncology Group performance status of 3, a minimum life expectancy of 3 months, and a minimum interval from initial treatment of 3 months if Re-RT were to be given with curative intent. Conclusions: This survey showed that a wide variation existed among ROs in their approach to Re-RT. Newer technologies in RT planning and delivery would be employed to facilitate normal tissue avoidance. The results of this study suggested that a consensus meeting was needed to establish guidelines for the practice and prospective evaluation of Re-RT.

Joseph, Kurian Jones [Cross Cancer Institute and University of Alberta, Edmonton, Alberta (Canada)], E-mail: kurianjo@cancerboard.ab.ca; Al-Mandhari, Zahid; Pervez, Nadeem; Parliament, Matthew [Cross Cancer Institute and University of Alberta, Edmonton, Alberta (Canada); Wu, Jackson [Tom Baker Cancer Center and University of Calgary, Calgary, Alberta (Canada); Ghosh, Sunita [Cross Cancer Institute and University of Alberta, Edmonton, Alberta (Canada); Tai, Patricia [Allan Blair Cancer Centre and University of Saskatchewan, Saskatchewan (Canada); Lian Jidong [Cross Cancer Institute and University of Alberta, Edmonton, Alberta (Canada); Levin, Wilfred [University of Toronto and Princess Margaret Hospital, Toronto (Canada)

2008-12-01

382

The potential for gene-targeted radiation therapy of cancers  

Microsoft Academic Search

Targeted cancer therapy is the mantra now chanted by oncologists of all types. Everyone hopes that the rapid expansion in the knowledge of cancer cell genetics, signaling, regulatory factors and other changes that underlie malignant transformation and metastasis will lead to innovative approaches for the treatment of cancers. To date, successful targeted therapies have been derived from pharmaceutical chemistry -

Igor G. Panyutin; Ronald D. Neumann

2005-01-01

383

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

E-print Network

with high or low perfusion with respect to the morphological information from CT [2-7]. Tighter radiation of functional parts of the lung. In previously reported clinical studies, SPECT-CT registrations were carriedEvaluating geometrical accuracy of image registration methods in SPECT guided radiation therapy

Hamarneh, Ghassan

384

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.

385

Tooth extraction by orthodontic force after radiation therapy: report of case  

SciTech Connect

This report presents a therapeutic approach to orthodontic tooth extraction in a patient at high risk for the development of osteoradionecrosis with conventional techniques. The rationale for this procedure is discussed in detail, combining principles of radiation biology, clinical radiation therapy, and biomechanics of tooth movement.

Rodu, B.; Filler, S.J.; Woodfin, G.K.

1985-12-01

386

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

387

Thyroxine administration during radiation therapy to the neck does not prevent subsequent thyroid dysfunction  

SciTech Connect

In an attempt to reduce the incidence of hypothyroidism following irradiation of the neck, we administered oral L-thyroxine in doses sufficient to suppress serum TSH to 20 patients receiving radiation therapy for Hodgkin's disease or other lymphomas. L-thyroxine was discontinued when radiation therapy was completed. Twenty similar patients who did not receive L-thyroxine during radiation therapy served as a control group. After a mean follow-up period of 33 months, seven patients (35%) in the L-thyroxine group developed elevation of serum TSH and were started on chronic L-thyroxine therapy. In the control group, after mean follow-up of 19 months, five patients (25%) developed elevation of TSH and were started on chronic L-thyroxine. We conclude that suppression of serum TSH during neck irradiation does not prevent subsequent thyroid dysfunction.

Bantle, J.P.; Lee, C.K.; Levitt, S.H.

1985-11-01

388

Technological Advancements and Error Rates in Radiation Therapy Delivery  

SciTech Connect

Purpose: Technological advances in radiation therapy (RT) delivery have the potential to reduce errors via increased automation and built-in quality assurance (QA) safeguards, yet may also introduce new types of errors. Intensity-modulated RT (IMRT) is an increasingly used technology that is more technically complex than three-dimensional (3D)-conformal RT and conventional RT. We determined the rate of reported errors in RT delivery among IMRT and 3D/conventional RT treatments and characterized the errors associated with the respective techniques to improve existing QA processes. Methods and Materials: All errors in external beam RT delivery were prospectively recorded via a nonpunitive error-reporting system at Brigham and Women's Hospital/Dana Farber Cancer Institute. Errors are defined as any unplanned deviation from the intended RT treatment and are reviewed during monthly departmental quality improvement meetings. We analyzed all reported errors since the routine use of IMRT in our department, from January 2004 to July 2009. Fisher's exact test was used to determine the association between treatment technique (IMRT vs. 3D/conventional) and specific error types. Effect estimates were computed using logistic regression. Results: There were 155 errors in RT delivery among 241,546 fractions (0.06%), and none were clinically significant. IMRT was commonly associated with errors in machine parameters (nine of 19 errors) and data entry and interpretation (six of 19 errors). IMRT was associated with a lower rate of reported errors compared with 3D/conventional RT (0.03% vs. 0.07%, p = 0.001) and specifically fewer accessory errors (odds ratio, 0.11; 95% confidence interval, 0.01-0.78) and setup errors (odds ratio, 0.24; 95% confidence interval, 0.08-0.79). Conclusions: The rate of errors in RT delivery is low. The types of errors differ significantly between IMRT and 3D/conventional RT, suggesting that QA processes must be uniquely adapted for each technique. There was a lower error rate with IMRT compared with 3D/conventional RT, highlighting the need for sustained vigilance against errors common to more traditional treatment techniques.

Margalit, Danielle N., E-mail: dmargalit@partners.org [Harvard Radiation Oncology Program, Boston, MA (United States); Harvard Cancer Consortium and Brigham and Women's Hospital/Dana Farber Cancer Institute, Boston, MA (United States); Chen, Yu-Hui; Catalano, Paul J.; Heckman, Kenneth; Vivenzio, Todd; Nissen, Kristopher; Wolfsberger, Luciant D.; Cormack, Robert A.; Mauch, Peter; Ng, Andrea K. [Harvard Cancer Consortium and Brigham and Women's Hospital/Dana Farber Cancer Institute, Boston, MA (United States)

2011-11-15

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

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

391

Characterization of a tungsten\\/gas multislit collimator for microbeam radiation therapy at the European Synchrotron Radiation Facility  

Microsoft Academic Search

Clinical microbeam radiation therapy (MRT) will require a multislit collimator with adjustable uniform slit widths to enable reliable Monte Carlo-based treatment planning. Such a collimator has been designed, fabricated of >99% tungsten [W] by Tecomet\\/Viasys (Woburn, Massachusetts, USA) and installed at the 6 GeV electron-wiggler-generated hard x-ray ID17 beamline of the European Synchrotron Radiation Facility. Its pair of 125 parallel,

E. Braeuer-Krisch; A. Bravin; L. Zhang; E. Siegbahn; J. Stepanek; H. Blattmann; D. N. Slatkin; J.-O. Gebbers; M. Jasmin; J. A. Laissue

2005-01-01

392

Combination of internal radiation therapy and hyperthermia to treat liver cancer  

SciTech Connect

Sixteen patients were treated for liver cancer (primary and metastatic) by a combination of internal radiation therapy with intra-arterial yttrium 90 microspheres and regional hyperthermia with electromagnetic radiation. Four patients have their liver disease apparently controlled; two had a partial regression of more than 50%; and two had a partial regression of less than 50%. The complications consisted of one case of radiation hepatitis and one of peptic ulcer.

Grady, E.D.; McLaren, J.; Auda, S.P.; McGinley, P.H.

1983-09-01

393

Technical note: a transparent template system for positioning independent radiation-therapy shielding blocks  

Microsoft Academic Search

To assist the radiation therapist\\/technologist with setting up patients for radiation therapy treatments, a set of accessories has been developed for placing a transparent template of the treatment-field border in the light-field of a radiation teletherapy unit. These accessories permit the efficient, accurate, and reproducible manual placement of independent lead-shielding blocks. Software has been developed to print templates on standard

Scott Cosby; Tai Yeung; Hans Schwendener

2001-01-01

394

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

395

The Clinical Development of Molecularly Targeted Agents in Combination With Radiation Therapy: A Pharmaceutical Perspective  

SciTech Connect

Summary: This paper explores historical and current roles of pharmaceutical industry sponsorship of clinical trials testing radiation therapy combinations with molecularly targeted agents and attempts to identify potential solutions to expediting further combination studies. An analysis of clinical trials involving a combination of radiation therapy and novel cancer therapies was performed. Ongoing and completed trials were identified by searching the (clinicaltrials.gov) Web site, in the first instance, with published trials of drugs of interest identified through American Society of Clinical Oncology, European CanCer Organisation/European Society for Medical Oncology, American Society for Radiation Oncology/European Society for Therapeutic Radiology and Oncology, and PubMed databases and then cross-correlated with (clinicaltrials.gov) protocols. We examined combination trials involving radiation therapy with novel agents and determined their distribution by tumor type, predominant molecular mechanisms examined in combination to date, timing of initiation of trials relative to a novel agent's primary development, and source of sponsorship of such trials. A total of 564 studies of targeted agents in combination with radiation therapy were identified with or without concomitant chemotherapy. Most studies were in phase I/II development, with only 36 trials in phase III. The tumor site most frequently studied was head and neck (26%), followed by non-small cell lung cancer. Pharmaceutical companies were the sponsors of 33% of studies overall and provided support for only 16% of phase III studies. In terms of pharmaceutical sponsorship, Genentech was the most active sponsor of radiation therapy combinations (22%), followed by AstraZeneca (14%). Most radiation therapy combination trials do not appear to be initiated until after drug approval. In phase III studies, the most common (58%) primary endpoint was overall survival. Collectively, this analysis suggests that such trials are not given priority by pharmaceutical companies. The potential reasons for this and some challenges and possible solutions are discussed.

Ataman, Ozlem U., E-mail: ouataman@hotmail.com [Global Medicines Development, AstraZeneca, Alderley Park, Macclesfield, Cheshire (United Kingdom); Sambrook, Sally J. [Global Medicines Development, AstraZeneca, Alderley Park, Macclesfield, Cheshire (United Kingdom)] [Global Medicines Development, AstraZeneca, Alderley Park, Macclesfield, Cheshire (United Kingdom); Wilks, Chris [Innovative Medicines, AstraZeneca, Alderley Park, Macclesfield, Cheshire (United Kingdom)] [Innovative Medicines, AstraZeneca, Alderley Park, Macclesfield, Cheshire (United Kingdom); Lloyd, Andrew [Global Medicines Development, AstraZeneca, Alderley Park, Macclesfield, Cheshire (United Kingdom)] [Global Medicines Development, AstraZeneca, Alderley Park, Macclesfield, Cheshire (United Kingdom); Taylor, Amanda E. [Yellow Delaney Communications Ltd, Wilmslow, Cheshire (United Kingdom)] [Yellow Delaney Communications Ltd, Wilmslow, Cheshire (United Kingdom); Wedge, Stephen R. [Innovative Medicines, AstraZeneca, Alderley Park, Macclesfield, Cheshire (United Kingdom)] [Innovative Medicines, AstraZeneca, Alderley Park, Macclesfield, Cheshire (United Kingdom)

2012-11-15

396

Ear lobe keloids, surgical excision followed by radiation therapy: a 10-year experience.  

PubMed

This retrospective study was conducted to analyze the recurrence of ear lobe keloids in 36 patients after surgical excision followed by radiation therapy. In all the cases keloids were excised and the surgical wound closed primarily. Following surgery, patients underwent 1800 cGy of radiation therapy in three equally divided doses over five to seven days. Most of our patients were young black females who developed keloids secondary to ear lobe piercing. Of the 36 patients followed for a mean period of 5.6 years, we noted only one (2.8%) recurrence. All the patients were followed for a minimum of two years. No serious complications were observed in our series. However, one patient developed radiation dermatitis followed by patchy hypopigmentation. We conclude that surgical excision followed by radiation therapy is a safe and effective method to control keloid recurrence in the ear lobe region. PMID:7805600

Chaudhry, M R; Akhtar, S; Duvalsaint, F; Garner, L; Lucente, F E

1994-10-01

397

Measurements of the neutron dose equivalent for various radiation qualities, treatment machines and delivery techniques in radiation therapy  

NASA Astrophysics Data System (ADS)

In radiation therapy, high energy photon and proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long term health of cancer patients. Due to the high biological effectiveness of neutrons in regards to cancer induction, small neutron doses can be important. This study quantified the neutron doses for different radiation therapy modalities. Most of the reports in the literature used neutron dose measurements free in air or on the surface of phantoms to estimate the amount of neutron dose to the patient. In this study, dose measurements were performed in terms of neutron dose equivalent inside an anthropomorphic phantom. The neutron dose equivalent was determined using track etch detectors as a function of the distance to the isocenter, as well as for radiation sensitive organs. The dose distributions were compared with respect to treatment techniques (3D-conformal, volumetric modulated arc therapy and intensity-modulated radiation therapy for photons; spot scanning and passive scattering for protons), therapy machines (Varian, Elekta and Siemens linear accelerators) and radiation quality (photons and protons). The neutron dose equivalent varied between 0.002 and 3 mSv per treatment gray over all measurements. Only small differences were found when comparing treatment techniques, but substantial differences were observed between the linear accelerator models. The neutron dose equivalent for proton therapy was higher than for photons in general and in particular for double-scattered protons. The overall neutron dose equivalent measured in this study was an order of magnitude lower than the stray dose of a treatment using 6 MV photons, suggesting that the contribution of the secondary neutron dose equivalent to the integral dose of a radiotherapy patient is small.

Hälg, R. A.; Besserer, J.; Boschung, M.; Mayer, S.; Lomax, A. J.; Schneider, U.

2014-05-01

398

Measurements of the neutron dose equivalent for various radiation qualities, treatment machines and delivery techniques in radiation therapy.  

PubMed

In radiation therapy, high energy photon and proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long term health of cancer patients. Due to the high biological effectiveness of neutrons in regards to cancer induction, small neutron doses can be important. This study quantified the neutron doses for different radiation therapy modalities. Most of the reports in the literature used neutron dose measurements free in air or on the surface of phantoms to estimate the amount of neutron dose to the patient. In this study, dose measurements were performed in terms of neutron dose equivalent inside an anthropomorphic phantom. The neutron dose equivalent was determined using track etch detectors as a function of the distance to the isocenter, as well as for radiation sensitive organs. The dose distributions were compared with respect to treatment techniques (3D-conformal, volumetric modulated arc therapy and intensity-modulated radiation therapy for photons; spot scanning and passive scattering for protons), therapy machines (Varian, Elekta and Siemens linear accelerators) and radiation quality (photons and protons). The neutron dose equivalent varied between 0.002 and 3 mSv per treatment gray over all measurements. Only small differences were found when comparing treatment techniques, but substantial differences were observed between the linear accelerator models. The neutron dose equivalent for proton therapy was higher than for photons in general and in particular for double-scattered protons. The overall neutron dose equivalent measured in this study was an order of magnitude lower than the stray dose of a treatment using 6 MV photons, suggesting that the contribution of the secondary neutron dose equivalent to the integral dose of a radiotherapy patient is small. PMID:24778349

Hälg, R A; Besserer, J; Boschung, M; Mayer, S; Lomax, A J; Schneider, U

2014-05-21

399

A prospective randomized comparison of radiation therapy plus lonidamine versus radiation therapy plus placebo as initial treatment of clinically localized but nonresectable nonsmall cell lung cancer  

SciTech Connect

The purpose was, by means of a multicenter, prospective randomized, placebo-controlled study, to assess the impact of adding the radiation-enhancing agent lonidamine to standard {open_quotes}curative-intent{close_quotes} radiation therapy upon overall survival, progression-free survival, and local progression-free survival of patients with clinically localized but nonresectable nonsmall cell lung cancer. Lonidamine, or the lonidamine-placebo, was administered at a dose of 265 mg/m{sup 2} in three divided daily doses. Drug therapy began 2 days prior to the initiation of radiation therapy and continued until progression of disease mandated a change in therapy. The radiation therapy dose was 55-60 Gy, at a daily dose of 1.8 Gy and five treatments per week. Patients with clinical Stage II or III nonsmall cell lung cancer were stratified within the treatment center, and within two histologic strata: epidermoid vs. other nonsmall cell cancers. A total of 310 patients were enlisted on study, 152 on the placebo arm and 158 on the lonidamine arm. The median survival durations were 326 and 392 days for the placebo and lonidamine-treated groups respectively, p = 0.41 for a comparison of the survival curves. Median progression-free survival and median local progression-free survival durations were 197 days and 341 days for placebo + radiation therapy vs. 230 days and 300 days for lonidamine + radiation therapy; p-values for the respective curves were 0.75 and 0.42. Although there were proportionately more lonidamine-treated patients than placebo-treated patients demonstrating continued local control in excess of 12 months, the numbers of patients still at risk after 24 months were too small for meaningful statistical analysis. This multicenter Phase III study failed to demonstrate a significant advantage in the lonidamine-treated population in overall patient survival, in progression-free survival, or in the median duration of local control. 25 refs., 3 figs., 3 tabs.

Scarantino, C.W. [Rex Cancer Center, Raleigh, NC (United States); McCunniff, A.J.; Evans, G. [Bowman-Gray School of Medicine, Winston-Salem, NC (United States); Young, C.W. [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Paggiarino, D.A. [Angelini Pharmaceuticals, Inc., River Edge, NJ (United States)

1994-07-30

400

Function of the parotid gland following radiation therapy for head and neck cancer  

SciTech Connect

The parotid gland was selected for study of its salivary output before and after radiation therapy for head and neck cancer. Before radiation therapy, a sialogram of the parotid gland was performed with the patient's head positioned for radiation therapy; a lateral radiographic view of the parotid gland was used to compare with the radiation treatment portal to determine the portion of the parotid gland to be irradiated. Samples of stimulated saliva were collected from the parotid gland before and at 1 and 6 months post-radiation. Eighteen patients with head and neck cancer who received radiation therapy were studied. The data showed that in the irradiation of nasopharyngeal, advanced oropharyngeal and Waldeyer's ring lesions, 100% of the parotid gland was irradiated; for the early oropharyngeal and hypopharyngeal lesions, from 30 to 90% of the parotid gland was irradiated and for the supraglottic and oral cavity lesions, 25 to 30% of the parotid gland was irradiated. When 100% of the parotid gland was irradiated, no saliva was produced at 1 month post-radiation; this remained the same when re-tested at 4 to 8 months, however, when any portion of the parotid gland was not irradiated, there was residual salivary function.

Cheng, V.S.T.; Downs, J.; Herbert, D.; Aramany, M.

1981-02-01

401

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

402

Development of Laser Accelerated Proton Beams for Radiation Therapy  

Microsoft Academic Search

Recent advances in laser technology have made proton (ion) acceleration possible using laser induced plasmas. In this presentation\\u000a we will review the theoretical and experimental results of laser-proton acceleration for radiotherapy applications. We will\\u000a report on our work progress in the development of a laser-proton therapy system at Fox Chase Cancer Center. The new proton\\u000a therapy system is designed as

C.-M. Ma; E. Fourkal; I. Veltchev; J. S. Li; J. Fan; T. Lin; A. Tafo

403

A helical microwave antenna for welding plaque during balloon angioplasty  

SciTech Connect

A catheter-based microwave helix antenna has been developed in an attempt to improve the long-term success of balloon angioplasty treatment of arteriosclerosis. When the balloon is inflated to widen vessels obstructed with plaque, microwave power is deposited in the plaque, heating it, and thereby fixing it in place. By optimizing the helix pitch angle and excitation frequency, the antenna radiation pattern can be adjusted to deposit microwave power preferentially in the plaque while avoiding overheating the healthy artery. The optimal power deposition patterns of helical antennas are analytically computed for four-layered concentric and four-layered nonconcentric cylindrical geometries, which model symmetric and asymmetric occluded arteries. Experiments were performed on occluded artery phantom models with a prototype antenna for both symmetric and asymmetric models, which matched the theoretical predictions well, indicating almost complete power absorption in the low-water-content simulated plaque.

Liu, P.; Rappaport, C.M. [Northeastern Univ., Boston, MA (United States). Electrical and Computer Engineering Dept.

1996-10-01

404

Breast Intensity-Modulated Radiation Therapy Reduces Time Spent With Acute Dermatitis for Women of All Breast Sizes During Radiation  

SciTech Connect

Purpose: To study the time spent with radiation-induced dermatitis during a course of radiation therapy for breast cancer in women treated with conventional or intensity-modulated radiation therapy (IMRT). Methods and Materials: The study population consisted of 804 consecutive women with early-stage breast cancer treated with breast-conserving surgery and radiation from 2001 to 2006. All patients were treated with whole-breast radiation followed by a boost to the tumor bed. Whole-breast radiation consisted of conventional wedged photon tangents (n = 405) earlier in the study period and mostly of photon IMRT (n = 399) in later years. All patients had acute dermatitis graded each week of treatment. Results: The breakdown of the cases of maximum acute dermatitis by grade was as follows: 3%, Grade 0; 34%, Grade 1; 61%, Grade 2; and 2%, Grade 3. The breakdown of cases of maximum toxicity by technique was as follows: 48%, Grade 0/1, and 52%, Grade 2/3, for IMRT; and 25%, Grade 0/1, and 75%, Grade 2/3, for conventional radiation therapy (p < 0.0001). The IMRT patients spent 82% of weeks during treatment with Grade 0/1 dermatitis and 18% with Grade 2/3 dermatitis, compared with 29% and 71% of patients, respectively, treated with conventional radiation (p < 0.0001). Furthermore, the time spent with Grade 2/3 toxicity was decreased in IMRT patients with small (p = 0.0015), medium (p < 0.0001), and large (p < 0.0001) breasts. Conclusions: Breast IMRT is associated with a significant decrease both in the time spent during treatment with Grade 2/3 dermatitis and in the maximum severity of dermatitis compared with that associated with conventional radiation, regardless of breast size.

Freedman, Gary M. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States)], E-mail: Gary.Freedman@FCCC.edu; Li Tianyu [Department of Biostatistics, Fox Chase Cancer Center, Philadelphia, PA (United States); Nicolaou, Nicos; Chen Yan; Ma, Charlie C.-M.; Anderson, Penny R. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States)

2009-07-01

405

Molecular PET/CT imaging-guided radiation therapy treatment planning.  

PubMed

The role of positron emission tomography (PET) during the past decade has evolved rapidly from that of a pure research tool to a methodology of enormous clinical potential. (18)F-fluorodeoxyglucose (FDG)-PET is currently the most widely used probe in the diagnosis, staging, assessment of tumor response to treatment, and radiation therapy planning because metabolic changes generally precede the more conventionally measured parameter of change in tumor size. Data accumulated rapidly during the last decade, thus validating the efficacy of FDG imaging and many other tracers in a wide variety of malignant tumors with sensitivities and specificities often in the high 90 percentile range. As a result, PET/computed tomography (CT) had a significant impact on the management of patients because it obviated the need for further evaluation, guided further diagnostic procedures, and assisted in planning therapy for a considerable number of patients. On the other hand, the progress in radiation therapy technology has been enormous during the last two decades, now offering the possibility to plan highly conformal radiation dose distributions through the use of sophisticated beam targeting techniques such as intensity-modulated radiation therapy (IMRT) using tomotherapy, volumetric modulated arc therapy, and many other promising technologies for sculpted three-dimensional (3D) dose distribution. The foundation of molecular imaging-guided radiation therapy lies in the use of advanced imaging technology for improved definition of tumor target volumes, thus relating the absorbed dose information to image-based patient representations. This review documents technological advancements in the field concentrating on the conceptual role of molecular PET/CT imaging in radiation therapy treatment planning and related image processing issues with special emphasis on segmentation of medical images for the purpose of defining target volumes. There is still much more work to be done and many of the techniques reviewed are themselves not yet widely implemented in clinical settings. PMID:19427800

Zaidi, Habib; Vees, Hansjörg; Wissmeyer, Michael

2009-09-01

406

Numerical assessment of radiation binary targeted therapy for HER-2 positive breast cancers: advanced calculations and radiation dosimetry  

NASA Astrophysics Data System (ADS)

In our previous publication (Mundy et al 2006 Phys. Med. Biol. 51 1377) we have described the theoretical assessment of our novel approach in radiation binary targeted therapy for HER-2 positive breast cancers and summarized the future directions in this area of research. In this paper we advanced the numerical analysis to show the detailed radiation dose distribution for various neutron sources in combination with the required boron concentration and allowed radiation skin doses. We once again proved the feasibility of the concept and will use these data and conclusions to start with the experimental verifications.

Sztejnberg Gonçalves-Carralves, Manuel L.; Jevremovic, Tatjana

2007-07-01

407

Delivery of therapeutic radioisotopes using nanoparticle platforms: potential benefit in systemic radiation therapy  

PubMed Central

Radiation therapy is an effective cancer treatment option in conjunction with chemotherapy and surgery. Emerging individualized internal and systemic radiation treatment promises significant improvement in efficacy and reduction of normal tissue damage; however, it requires cancer cell targeting platforms for efficient delivery of radiation sources. With recent advances in nanoscience and nanotechnology, there is great interest in developing nanomaterials as multifunctional carriers to deliver therapeutic radioisotopes for tumor targeted radiation therapy, to monitor their delivery and tumor response to the treatment. This paper provides an overview on developing nanoparticles for carrying and delivering therapeutic radioisotopes for systemic radiation treatment. Topics discussed in the review include: selecting nanoparticles and radiotherapy isotopes, strategies for targeting nanoparticles to cancers, together with challenges and potential solutions for the in vivo delivery of nanoparticles. Some examples of using nanoparticle platforms for the delivery of therapeutic radioisotopes in preclinical studies of cancer treatment are also presented. PMID:24198480

Zhang, Longjiang; Chen, Hongwei; Wang, Liya; Liu, Tian; Yeh, Julie; Lu, Guangming; Yang, Lily; Mao, Hui

2010-01-01

408

Meningeal hemangiopericytoma: defining the role for radiation therapy  

Microsoft Academic Search

Meningeal hemangiopericytoma is a rare neoplasm arising from perivascular pericytes. Accounting for 50 Gray providing superior long-term disease-free survival. Meningeal hemangiopericytoma are characterized by a slow, but progressive radiographic response to ionizing radiation, not unlike other radiated, highly vascular brain lesions, such as arteriovenous malformations. A retrospective review of clinical demographics, sites of meningeal origin, radiographic and pathologic findings and

Kenneth T. Bastin; Minesh P. Mehta

1992-01-01

409

Method and devices for performing stereotactic microbeam radiation therapy  

Microsoft Academic Search

A radiation delivery system generally includes either a synchrotron source or a support frame and a plurality of microbeam delivery devices supported on the support frame, both to deliver a beam in a hemispherical arrangement. Each of the microbeam delivery devices or synchrotron irradiation ports is adapted to deliver at least one microbeam of radiation along a microbeam delivery axis,

Dilmanian; F. Avraham

2010-01-01

410

Exploiting sensitization windows of opportunity in hyper and hypo-fractionated radiation therapy  

PubMed Central

In contrast to the conventional radiotherapy/chemoradiotherapy paradigms used in the treatment of majority of cancer types, this review will describe two areas of radiobiology, hyperfractionated and hypofractionated radiation therapy, for cancer treatment focusing on application of novel concepts underlying these treatment modalities. The initial part of the review discusses the phenomenon of hyper-radiation sensitivity (HRS) at lower doses (0.1 to 0.6 Gy), describing the underlying mechanisms and how this could enhance the effects of chemotherapy, particularly, in hyperfractionated settings. The second part examines the radiobiological/physiological mechanisms underlying the effects of high-dose hypofractionated radiation therapy that can be exploited for tumor cure. These include abscopal/bystander effects, activation of immune system, endothelial cell death and effect of hypoxia with re-oxygenation. These biological properties along with targeted dose delivery and distribution to reduce normal tissue toxicity may make high-dose hypofractionation more effective than conventional radiation therapy for treatment of advanced cancers. The novel radiation physics based methods that take into consid