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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

Effective Narrow-Band UVB Radiation Therapy Suppresses the IL23\\/IL17 Axis in Normalized Psoriasis Plaques  

Microsoft Academic Search

Narrow-band UVB radiation (NB-UVB) therapy offers a well-established treatment modality for psoriasis. However, despite the common use of this form of treatment, the mechanism of action of NB-UVB is not well understood. We studied a group of 14 patients with moderate-to-severe psoriasis treated with carefully titrated and monitored NB-UVB for 6 weeks. Lesional plaques were classified as normalized (n=8) or

Leanne M Johnson-Huang; Mayte Suárez-Fariñas; Mary Sullivan-Whalen; Patricia Gilleaudeau; James G Krueger; Michelle A Lowes

2010-01-01

3

Effective narrow-band UVB radiation therapy suppresses the IL-23/IL-17 axis in normalized psoriasis plaques.  

PubMed

Narrow-band UVB radiation (NB-UVB) therapy offers a well-established treatment modality for psoriasis. However, despite the common use of this form of treatment, the mechanism of action of NB-UVB is not well understood. We studied a group of 14 patients with moderate-to-severe psoriasis treated with carefully titrated and monitored NB-UVB for 6 weeks. Lesional plaques were classified as normalized (n=8) or nonresponsive (n=6) based on their histological improvement and normalization. We characterized lesional myeloid dendritic cells (DCs) and T cells and their inflammatory mediators using immunohistochemistry and real-time PCR. NB-UVB suppressed multiple parameters of the IL-23/IL-17 pathway in normalized plaques, but not in nonresponsive plaques. NB-UVB decreased the numbers of CD11c(+) DCs, specifically CD1c(-)CD11c(+) "inflammatory" DCs, and their products, IL-20, inducible nitric oxide synthase, IL-12/23p40, and IL-23p19. Furthermore, effective NB-UVB suppressed IL-17 and IL-22 mRNAs, which strongly correlated with lesion resolution. Therefore, in addition to its known role in suppressing IFN-? production, NB-UVB radiation therapy can also target the IL-17 pathway to resolve psoriatic inflammation.JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article, please go to http://www.nature.com/jid/journalclub. PMID:20555351

Johnson-Huang, Leanne M; Suárez-Fariñas, Mayte; Sullivan-Whalen, Mary; Gilleaudeau, Patricia; Krueger, James G; Lowes, Michelle A

2010-11-01

4

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 ...

5

Radiation Therapy  

MedlinePLUS

... get email 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 ...

6

Radiation therapy  

MedlinePLUS

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

7

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, ...

8

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

SciTech Connect

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

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

1989-04-01

9

Radiation Therapy.  

National Technical Information Service (NTIS)

Guidelines are presented for the development of radiation therapy capability in northwestern Pennsylvania. A surplus of megavoltage (cobalt therapy, linear accelerator) capability exists in the area, (as of 1976) therefore recommendations are made for one...

1976-01-01

10

Gene therapy for the vulnerable plaque  

Microsoft Academic Search

Rupture of coronary atherosclerotic plaque and subsequent formation of an occlusive intracoronary thrombus (Figure 410-1)\\u000a are the major events precipitating acute coronary syndromes [1–6]. The vulnerable plaque is smaller in size [7], richer in lipids [1],[2], and more infiltrated with macrophages [2,3,8–10] than the stable, fibromuscular lesion. Therefore, lowering the lipid and\\/or macrophage pools stored in the plaque may “stabilize”

Douglas W. Losordo; Jeffrey M. Isner

11

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

12

Radiation Therapy  

MedlinePLUS

... the body, making the person very sick. Radiation therapy kills cancer cells and keeps them from growing and multiplying. The ... people may first have surgery to remove cancer cells or tumors and then have ... depends on the kind of cancer he or she has. A doctor called an ...

13

Radiation Therapy  

MedlinePLUS

... after radiation therapy has ended. Skin damage or changes. The skin around the treatment area may be red, sensitive, or easily irritated in the days, weeks, and months during and after treatment. ... texture may change. (Most symptoms of skin damage are temporary, although ...

14

Radiation Therapy for Osteosarcoma  

MedlinePLUS

... for osteosarcoma Next Topic Clinical trials for osteosarcoma Radiation therapy for osteosarcoma Radiation therapy uses high-energy ... back or surgery is not possible. External beam radiation therapy This is the type of radiation therapy ...

15

Topical therapies for the treatment of plaque psoriasis.  

PubMed

Psoriasis is a chronic inflammatory skin disease affecting approximately 2% of the US population. Plaque psoriasis, characterized by erythematous lesions covered with silvery scales, is the most common form. In the absence of a cure, long-term control is important for the management of this disease. Topical corticosteroids are the primary treatment strategy for most mild to moderate cases of psoriasis. For more severe cases, topical corticosteroids often are combined with other antipsoriatic agents to prolong the remission period between disease outbreaks, manage isolated flares during therapy, and ease the transition between therapies. With the availability of multiple formulations of topical antipsoriatic agents, including multiple formulations of topical corticosteroids with different potencies, physicians have a large number of treatment strategies for their patients with psoriasis. PMID:19916297

Bagel, Jerry

2009-10-01

16

Radiation Therapy for Bone Cancer  

MedlinePLUS

... bone cancer Next Topic Chemotherapy for bone cancer Radiation therapy for bone cancer Radiation therapy uses high- ... control symptoms like pain and swelling. Intensity-modulated radiation therapy Intensity-modulated radiation therapy (IMRT) is an ...

17

Radiation Therapy for Cancer  

MedlinePLUS

... basic unit of light and other forms of electromagnetic radiation . It can be thought of as a ... radiation therapy in fewer sessions, using smaller radiation fields and higher doses than 3D-CRT in most ...

18

Dosimetry and physical treatment planning for iodine eye plaque therapy  

SciTech Connect

The dosimetry of eye plaques loaded with iodine-125 seeds (type 6702) was performed by means of computer calculations and measurements with thermoluminescent dosimeters (TLD). Measurements of the depth dose distribution (2-25.5 mm) along the transverse axis of a single seed were performed in water equivalent phantom material. The transverse axis attenuation and geometry factor F(r) was obtained by applying a least squares fit to the measured data. Based on the resulting radial dose function, a computer program was developed which calculates dose distributions within the eye for arbitrary loading and placement of the eye plaque. The computational results were verified by TLD measurements in an eye phantom.

Alberti, W.; Pothmann, B.; Tabor, P.; Muskalla, K.; Hermann, K.P.; Harder, D. (Alfried Krupp Krankenhaus, Essen, (F.R.Germany))

1991-05-01

19

MICROSPHERES FOR RADIATION THERAPY  

Microsoft Academic Search

The treatment of malignant tumors with ionizing radiation using ceramic ; microspheres that can be localized at selected sites for interstitial therapy is ; discussed. Thus, radiation damage in healthy tissues can be minimized by ; tailoring radioactivity to control dose, dose rate, and volume of tissue ; irradiated. The mean life, radiation energies, and beta-gamma dose can be ;

J. F. Perry; M. K. Loken; J. P. Ryan; L. D. MacLean

1962-01-01

20

Microenvironment and Radiation Therapy  

PubMed Central

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

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

2013-01-01

21

Radiation Therapy (For Parents)  

MedlinePLUS

... temporary, it can be permanent. Sore Mouth and Tooth Decay The tissues of the mouth may be sore ... and there may be an increased risk of tooth decay if a child received radiation therapy to the ...

22

Radiation Therapy. Guideline Series.  

National Technical Information Service (NTIS)

Guidelines adopted by the Health Systems Agency of Southwestern Pennsylvania to facilitate the development of a radiation therapy program are presented. Using the guidelines, subarea planning councils, in collaboration with health systems agency staff, ar...

1978-01-01

23

Stereotactic Body Radiation Therapy  

Microsoft Academic Search

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

Laura A. Dawson

24

Vitamin B12 Cream Containing Avocado Oil in the Therapy of Plaque Psoriasis  

Microsoft Academic Search

Background: There are already many effective topical therapies available for use in the treatment of chronic plaque psoriasis. Unfortunately, these treatments are often associated with a rather significant risk of undesirable effects. Objective and Methods: In this randomized, prospective clinical trial, the effects of the vitamin D3 analog calcipotriol were evaluated against those of a recently developed vitamin B12 cream

Markus Stücker; Ulrike Memmel; Matthias Hoffmann; Joachim Hartung; Peter Altmeyer

2001-01-01

25

Palliative radiation therapy.  

PubMed

Animal owners may be reluctant to have pets with incurable cancer subjected to euthanasia. Palliative radiation therapy may provide significant relief of pain in such pets. Palliative irradiation is comprised of a few radiation treatments, frequently given over a short time and using larger than normal fractional doses. Animals tolerate palliative irradiation well, and recent reports attest to the usefulness of palliative radiation to relieve discomfort associated with both skeletal and extraskeletal tumors. Although there is more to learn regarding the response of canine and feline tumors to palliative irradiation, it is a proven modality for relief of pain in many incurable cancer patients. PMID:8532977

Thrall, D E; LaRue, S M

1995-08-01

26

The antibacterial effect of photodynamic therapy in dental plaque-derived biofilms  

PubMed Central

Background and Objective Photodynamic therapy (PDT) has been advocated as an alternative to antimicrobial agents to suppress subgingival species and treat periodontitis. Bacteria located within dense biofilms, such as those encountered in dental plaques, have been found to be relatively resistant to antimicrobial therapy. In the present study, we investigated the ability of PDT to affect bacteria resistant in biofilms by comparing the photodynamic effects of methylene blue (MB) on human dental plaque microorganisms in planktonic phase and in biofilms. Material and Methods Dental plaque samples were obtained from 10 subjects with chronic periodontitis. Suspensions of plaque microorganisms from 5 subjects were sensitized with MB (25 ?g/ml) for 5 minutes followed by exposure to red light. Multi-species microbial biofilms developed from the same plaque samples were also exposed to MB (25 ?g/ml) and the same light conditions as their planktonic counterparts. In a second set of experiments, biofilms were developed with plaque bacteria from 5 subjects and sensitized with 25 and 50 ?g/ml MB followed by exposure to light as above. After PDT, survival fractions were calculated from colony-forming unit counts. Results In suspension, PDT produced approximately 63% killing of bacteria. In biofilms, the effect of PDT resulted in much lower reductions of microorganisms (32% maximal killing). Conclusion Oral bacteria in biofilms are less affected by PDT than bacteria in planktonic phase. The antibacterial effect of PDT is reduced in biofilm bacteria but not to the same degree as has been reported for treatment with antibiotics under similar conditions.

Fontana, C. R.; Abernethy, A. D.; Som, S.; Ruggiero, K.; Doucette, S.; Marcantonio, R. C.; Boussios, C. I.; Kent, R.; Goodson, J. M.; Tanner, A. C. R.; Soukos, N. S.

2009-01-01

27

Radiation Therapy for Soft Tissue Sarcomas  

MedlinePLUS

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

28

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

29

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

PubMed Central

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

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

2012-01-01

30

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

PubMed

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

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

2013-01-01

31

[Problems after radiation therapy].  

PubMed

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

Karasawa, Kumiko

2014-01-01

32

Technical advances in radiation therapy  

SciTech Connect

Substantial advances have been made in radiation therapy. Many of these advances can be applied in most radiation therapy departments without expensive improvements in equipment. Changes in radiation fractionation, chemotherapeutic sensitization, intraoperative radiation, and interstitial implants can be performed with experience and improved physician training in most medium-sized departments. Advances that require investments in expensive equipment such as particle radiation and hyperthermia will need to be evaluated at designated treatment centers. 106 references.

Sause, W.T.

1986-08-01

33

Radiation Therapy for Testicular Cancer  

MedlinePLUS

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

34

[Radiation therapy in thyroid cancer].  

PubMed

Anaplastic thyroid cancers represent 1-2% of all thyroid tumours and are of very poor prognosis even with multimodality treatment including external beam radiation therapy. Conversely, differentiated thyroid carcinomas (at least 80% of thyroid cancers) hamper good prognosis with surgery with or without radioiodine and there is hardly any room for external beam radiation therapy. Insular and medullar carcinomas have intermediary prognosis and are rarely irradiated. We aimed to update recommendations for external beam irradiation in these different clinical situations and put in light the benefits of new irradiations techniques. A search of the French and English literature was performed using the following keywords: thyroid carcinoma, anaplastic, chemoradiation, radiation therapy, surgery, histology and prognostic. Non-mutilating surgery (often limited to debulking) followed by systematic external beam radiation therapy is the standard of care in anaplastic thyroid cancers (hyperfractionated-accelerated radiation therapy with low-dose weekly doxorubicin with or without cisplatin if possible). Given anaplastic thyroid cancers' median survival of 10 months or less, neoadjuvant and adjuvant chemotherapy may also be discussed. Ten-year survival rates for patients with papillary, follicular and Hürthle-cell carcinomas are 93%, 85%, and 76%, respectively. Massive primary incompletely resected iodine-negative disease indicates external beam radiation therapy. Older age (45 or 60-year-old), poor-prognosis histological variants (including tall cell cancers) and insular cancers are increasingly reported as criteria for external beam radiation therapy. Massive extracapsular incompletely resected nodal medullary disease suggests external beam radiation therapy. Radiation therapy morbidity has been an important limitation. However, intensity modulated radiation therapy (IMRT) offers clear dosimetric advantages on tumour coverage and organ sparing, reducing late toxicities to less than 5%. The role of radiation therapy is evolving for anaplastic thyroid cancers using multimodal strategies and new chemotherapy molecules, and for differentiated cancers using minor criteria, such as histological variants, with IMRT becoming a standard of care. PMID:23763764

Sun, X S; Guevara, N; Fakhry, N; Sun, S-R; Marcy, P-Y; Santini, J; Bosset, J-F; Thariat, J

2013-06-01

35

The development and potential of acoustic radiation force impulse (ARFI) imaging for carotid artery plaque characterization.  

PubMed

Stroke is the third leading cause of death and long-term disability in the USA. Currently, surgical intervention decisions in asymptomatic patients are based upon the degree of carotid artery stenosis. While there is a clear benefit of endarterectomy for patients with severe (> 70%) stenosis, in those with high/moderate (50-69%) stenosis the evidence is less clear. Evidence suggests ischemic stroke is associated less with calcified and fibrous plaques than with those containing softer tissue, especially when accompanied by a thin fibrous cap. A reliable mechanism for the identification of individuals with atherosclerotic plaques which confer the highest risk for stroke is fundamental to the selection of patients for vascular interventions. Acoustic radiation force impulse (ARFI) imaging is a new ultrasonic-based imaging method that characterizes the mechanical properties of tissue by measuring displacement resulting from the application of acoustic radiation force. These displacements provide information about the local stiffness of tissue and can differentiate between soft and hard areas. Because arterial walls, soft tissue, atheromas, and calcifications have a wide range in their stiffness properties, they represent excellent candidates for ARFI imaging. We present information from early phantom experiments and excised human limb studies to in vivo carotid artery scans and provide evidence for the ability of ARFI to provide high-quality images which highlight mechanical differences in tissue stiffness not readily apparent in matched B-mode images. This allows ARFI to identify soft from hard plaques and differentiate characteristics associated with plaque vulnerability or stability. PMID:21447606

Allen, Jason D; Ham, Katherine L; Dumont, Douglas M; Sileshi, Bantayehu; Trahey, Gregg E; Dahl, Jeremy J

2011-08-01

36

Effect of atorvastatin therapy on oxidant-antioxidant status and atherosclerotic plaque formation  

PubMed Central

Background: The aim of this study was to determine the oxidant–antioxidant status and lipid peroxidation products, as well as paraoxonase and atherosclerotic plaque formation, in a hypercholesterolemic atherosclerosis rabbit model to investigate the effects of atorvastatin in the atherosclerotic process. Methods: Forty male New Zealand rabbits were divided into four groups, ie, a control group receiving standard pellets, a group receiving atorvastatin therapy, a hypercholesterolemic group receiving an atherogenic diet, and a group receiving both an atherogenic diet and atorvastatin. Results: The atherogenic diet increased the levels of low-density lipoprotein (LDL) thiobarbituric acid reactive substances (1.84 vs 3.79 nmol/mg protein) and LDL-conjugated diene (147 vs 318 ?mol/mg protein) after induction of oxidation by Cu2+, despite an increase of superoxide dismutase activity. Treatment with atorvastatin limited LDL oxidation significantly (LDL thiobarbituric acid reactive substances 2.19 nmol/mg protein, LDL-conjugated diene 222 ?mol/mg protein). Paraoxonase, which prevents LDL oxidation and inactivates LDL-derived oxidized phospholipids, showed a pronounced decrease in the group receiving the atherogenic diet (110 U/L to 28 U/L), and atorvastatin treatment increased paraoxonase activity. Histological examination of arcus aorta tissues from the hypercholesterolemic group showed abundant plaque formation surrounding and obstructing the lumen, whereas treatment with atorvastatin prevented or limited plaque formation, keeping the plaque thin and localized. Conclusion: Atorvastatin has dramatic antiatherosclerotic effects, part of which seems to be due to the antioxidant features of the parent drug and/or its metabolites, favoring inhibition of LDL oxidation.

Sezer, Ebru Demirel; Sozmen, Eser Yildirim; Nart, Deniz; Onat, Taner

2011-01-01

37

Radiation Therapy for Lung Cancer  

MedlinePLUS

... trials completed in the past proving that radiation therapy kills cancer cells and is safe long term. For more information ... be used to treat lung cancer noninvasively. Radiation therapy works within cancer cells by damaging their ability to multiply. When these ...

38

The Radiation Therapy Planning Problem  

Microsoft Academic Search

this paper is to describe mathematicalaspects of radiation therapy planning to readers with a background inapplied mathematics.The use of X-rays for cancer therapy began a few days after their discovery.Wilhelm Rontgen announced the discovery of X-rays on December28, 1895, and Emil Grubbe used them for cancer therapy on January 12,1896 [40]. X-rays are still the most common form of radiation

Christoph Borgers

1997-01-01

39

Radiation Therapy for Pituitary Adenomas  

Microsoft Academic Search

Radiation therapy offers another means of therapy for pituitary adenomas when roles for medical therapy and surgery have been\\u000a exhausted. Technological advancements in medical physics have revolutionized modern day radiotherapy for pituitary adenomas.\\u000a A variety of treatment modalities now exist, all of which offer higher degree of accuracy and safety in radiation delivery.\\u000a Very high tumor local control rates and

Helen A. Shih; Jay S. Loeffler

40

Drug Therapies to Prevent Coronary Plaque Rupture and Erosion: Present and Future  

Microsoft Academic Search

Patients at high risk for coronary heart disease usually have a number of atherosclerotic plaques in their coronary arteries. Some plaques grow inward and, once they have caused a critical degree of luminal stenosis, lead to chronic anginal symptoms. Other plaques grow outward and remain silent unless they disrupt and trigger an acute coronary event. Either type of plaque may

P. T. Kovanen; M. Mäyränpää; K. A. Lindstedt

41

Radiation Therapy Side Effects Sheets  

Cancer.gov

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

42

The Development and Potential of Acoustic Radiation Force Impulse (ARFI) Imaging for Carotid Artery Plaque Characterization  

PubMed Central

Stroke is the third leading cause of death and long-term disability in the U.S. Currently, surgical intervention decisions in asymptomatic patients are based upon the degree of carotid artery stenosis. While there is a clear benefit of endarterectomy for patients with severe (>70%) stenosis, in those with high/moderate (50–69%) stenosis the evidence is less clear. Evidence suggests ischemic stroke is associated less with calcified and fibrous plaques than with those containing softer tissue, especially when this it is accompanied by a thin fibrous cap. A reliable mechanism for the identification of individuals with atherosclerotic plaques which confer the highest risk for stroke is fundamental to the selection of patients for vascular interventions. Acoustic Radiation Force Impulse (ARFI) imaging is a new ultrasonic-based imaging method that characterizes the mechanical properties of tissue by measuring displacement resulting from applied short duration acoustic radiation force. These displacements provide information about the local mechanical properties of tissue and can differentiate between soft and hard areas. Because arterial walls, soft tissue, atheromas, and calcifications have a wide range in their stiffness properties, they represent excellent candidates for ARFI imaging. We present information from early phantom experiments and excised human limb studies to in vivo carotid artery scans and provide evidence for the ability of ARFI to provide high quality images which highlight mechanical differences in tissue stiffness not readily apparent in matched B-mode images. This allows ARFI to identify soft from hard plaques and differentiate characteristics associated with plaque vulnerability or stability.

Allen, Jason D.; Ham, Katherine L.; Dumont, Douglas M.; Sileshi, Bantayehu; Trahey, Gregg E.; Dahl, Jeremy J.

2012-01-01

43

All field simultaneous radiation therapy  

US Patent & Trademark Office Database

This invention describes a system for generating multiple simultaneous tunable electron and photon beams and monochromatic x-rays for all field simultaneous radiation therapy (AFSRT), tumor specific AFSRT and screening for concealed elements worn on to the body or contained in a container. Inverse Compton scattering renders variable energy spent electron and tunable monochromatic x-rays. It's spent electron beam is reused for radiation with electron beam or to generate photon beam. Tumor specific radiation with Auger transformation radiation is facilitated by exposing high affinity tumor bound heavy elements with external monochromatic x-rays. Heavy elements like directly iodinated steroid molecule that has high affinity binding to estrogen receptor in breast cancer and to iodinated testosterone in prostate cancer or with directly implanted nanoparticles into the tumor are exposed with tuned external monochromatic x-rays for tumor specific radiation therapy. Likewise, screening element's atom's k, l, m, n shell specific Auger transformation radiation generated by its exposure to external monochromatic x-rays is used to screen for concealed objects. Multiple beam segments from a beam storage ring or from octagonal beam lines are simultaneously switched on for simultaneous radiation with multiple beams. The beam on time to expose a tumor or an object is only a few seconds. It also facilitates breathing synchronized radiation therapy. The intensity modulated radiation therapy (IMRT) and intensity modulated screening for concealed objects (IMSFCO) is rendered by varying beam intensities of multiple simultaneous beams. The isocentric additive high dose rate from simultaneously converging multiple beams, the concomitant hyperthermia and chemotherapy and tumor specific radiation therapy and the AFSRT's very low radiation to the normal tissue all are used to treat a tumor with lower radiation dose and to treat a radioresistant and multiple times recurrent tumors that heave no other alternative treatments.

2012-05-08

44

Radiation Therapy and You: Support for People with Cancer  

MedlinePLUS

Radiation Therapy and You: Support for People With Cancer In English En español Posted: 04/20/2007 Radiation Therapy and You About This Book Questions and Answers About Radiation Therapy External Beam Radiation Therapy Internal Radiation Therapy ...

45

Method for microbeam radiation therapy  

DOEpatents

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

Slatkin, Daniel N. (Sound Beach, NY); Dilmanian, F. Avraham (Yaphank, NY); Spanne, Per O. (Shoreham, NY)

1994-01-01

46

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

47

External Radiation Therapy  

MedlinePLUS Videos and Cool Tools

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

48

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

49

A modified COMS plaque for iris melanoma  

PubMed Central

Melanoma of the iris is a rare condition compared to posterior ocular tumors and in this case report we present a 51-year-old female patient with diffuse iris melanoma. Traditional COMS (Collaborative Ocular Melanoma Study) plaques are used at our institution for radiation therapy, so a novel modification of the traditional plaque was required to allow better conformance with placement on the cornea. The usual silastic insert was machined to dimensions in compliance with the cornea, placed without incident, and treatment delivered with excellent patient tolerance of the modified plaque.

Vasudev, Deepta; Rice, Roger K.; Goldbaum, Michael; Mundt, Arno J.

2011-01-01

50

Current status of vulnerable plaque detection.  

PubMed

Critical coronary stenoses have been shown to contribute to only a minority of acute coronary syndromes (ACS) 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 noninvasive imaging techniques have shown the potential to identify these high-risk plaques. The anatomical characteristics of the vulnerable plaque such as thin cap fibroatheroma and lipid pool can be identified with angioscopy, high frequency intravascular ultrasound, intravascular MRI, and optical coherence tomography. Efforts have also been made to recognize active inflammation in high-risk plaques using intravascular thermography. Plaque chemical composition by measuring electromagnetic radiation using spectroscopy is also an emerging technology to detect vulnerable plaques. Noninvasive imaging with MRI, CT, and PET also holds the potential to differentiate between low and high-risk plaques. However, at present none of these imaging modalities are able to detect vulnerable plaque neither has been shown to definitively predict outcome. Nevertheless in contrast, there has been a parallel development in the physiological assessment of advanced atherosclerotic coronary artery disease. Thus recent trials using fractional flow reserve in patients with modest non flow-limiting stenoses have shown that deferral of PCI with optimal medical therapy in these patients is superior to coronary intervention. 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:19670307

Sharif, Faisal; Murphy, Ross T

2010-01-01

51

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2010 CFR

... Radiation therapy simulation system. 892.5840...SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY... Radiation therapy simulation system. (a) Identification... A radiation therapy simulation system is...

2009-04-01

52

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2010 CFR

... Radiation therapy simulation system. 892.5840...SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY... Radiation therapy simulation system. (a) Identification... A radiation therapy simulation system is...

2011-04-01

53

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2010 CFR

... Radiation therapy simulation system. 892.5840...SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY... Radiation therapy simulation system. (a) Identification... A radiation therapy simulation system is...

2010-04-01

54

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2010 CFR

... Radiation therapy simulation system. 892.5840...SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY... Radiation therapy simulation system. (a) Identification... A radiation therapy simulation system is...

2012-04-01

55

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2010 CFR

... Radiation therapy simulation system. 892.5840...SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY... Radiation therapy simulation system. (a) Identification... A radiation therapy simulation system is...

2008-04-01

56

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.

Kaliberov, Sergey A.; Buchsbaum, Donald J.

2013-01-01

57

Health Systems Analysis: Radiation Therapy Services.  

National Technical Information Service (NTIS)

A plan for the distribution of radiation therapy services within Health Services Area I (HSA I) is presented in this report. Four problems concerning health status or health system aspects of megavoltage radiation therapy services within HSA I are identif...

1981-01-01

58

Topical therapies for the treatment of plaque psoriasis: systematic review and network meta-analyses.  

PubMed

The majority of people with psoriasis have localized disease, where topical therapy forms the cornerstone of treatment. We set out to summarize evidence on the relative efficacy, safety and tolerability of different topical treatments used in plaque psoriasis. We undertook a systematic review and meta-analyses of randomized trial data of U.K.-licensed topical therapies. The primary outcome was clear or nearly clear status stratified for (i) trunk and limbs; and (ii) scalp. Network meta-analyses allowed ranking of treatment efficacy. In total, 48 studies were available for trunk and limb psoriasis, and 17 for scalp psoriasis (22,028 patients in total); the majority included people with at least moderate severity psoriasis. Strategies containing potent corticosteroids (alone or in combination with a vitamin D analogue) or very potent corticosteroids dominated the treatment hierarchy at both sites (trunk and limbs, scalp); coal tar and retinoids were no better than placebo. No significant differences in achievement of clear or nearly clear status were observed between twice- and once-daily application of the same intervention or between any of the following: combined vitamin D analogue and potent corticosteroid (applied separately or in a single product), very potent corticosteroids, or potent corticosteroids (applied twice daily). Investigator and patient assessment of response differed significantly for some interventions (response rates to very potent corticosteroids: 78% and 39%, respectively). No significant differences were noted for tolerability or steroid atrophy, but data were limited. In conclusion, corticosteroids are highly effective in psoriasis when used continuously for up to 8 weeks and intermittently for up to 52 weeks. Coal tar and retinoids are of limited benefit. There is a lack of long-term efficacy and safety data available on topical interventions used for psoriasis. PMID:23413913

Samarasekera, E J; Sawyer, L; Wonderling, D; Tucker, R; Smith, C H

2013-05-01

59

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

60

A multicenter, open-label study of repeat courses of intramuscular alefacept in combination with other psoriasis therapies in patients with chronic plaque psoriasis  

Microsoft Academic Search

OBJECTIVE: To evaluate the safety and efficacy of multiple courses of alefacept in combination with traditional psoriasis therapy for the treatment of chronic plaque psoriasis (CPP). METHODS: Patients with CPP requiring systemic therapy were eligible for this study. Patients received up to three courses of intramuscular alefacept 15 mg once weekly for 12 weeks. One concomitant psoriasis therapy (topical agents,

Gerald G. Krueger; Alice B. Gottlieb; Wolfram Sterry; Neil Korman; Peter Van De Kerkhof

2008-01-01

61

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

PubMed Central

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

2011-01-01

62

Novel approaches using radiation therapies.  

PubMed

The updates of the Danish DBCG 82b trial and the British Columbia trial have confirmed a significant overall survival benefit with postoperative radiation therapy in patients with high-risk disease. These trials together with in-depth analyses of previous studies suggest that the mechanism of the survival benefit is eradication of subclinical locoregional deposits of tumor cells with a potential for further dissemination if left untreated. Despite these findings, several questions remain largely unanswered concerning the optimal way to integrate radiation therapy into routine clinical practice. For instance, which subgroups are likely to benefit from comprehensive treatment including the peripheral lymphatics as opposed to treatment of the breast/chest wall alone? The available randomized trials and overviews have convincingly demonstrated that it is essential to minimize long-term radiation side effects in the myocardium in order to achieve an overall survival benefit. An appropriate treatment technique is therefore essential. Individual treatment planning should be encouraged since some patients have an "unfavorable anatomy" with the heart located anteriorly in the mediastinum. Such patients may receive a high cardiac dose-volume even with conventional tangential field irradiation that does not include the internal mammary nodes. PMID:9928563

Rutqvist, L E

1998-01-01

63

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

64

Measurement of intima-media thickness vs. carotid plaque: uses in patient care, genetic research and evaluation of new therapies  

Microsoft Academic Search

Intima-media thickness (IMT) has been measured for over 20 years, and is widely regarded as a surrogate for atherosclerosis. However, inthe carotidarteries atherosclero- sis is focal, manifesting as plaques. IMT is often measured deliberately where no plaque exists, or multiple measure- ments may be averaged, including only one or two that intersect plaque. IMTand plaque are biologically and geneti- cally

J. David Spence

2006-01-01

65

Melioidosis: reactivation during radiation therapy  

SciTech Connect

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

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

1980-05-01

66

Galactic Cosmic Radiation Leads to Cognitive Impairment and Increased A? Plaque Accumulation in a Mouse Model of Alzheimer's Disease  

PubMed Central

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

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

2012-01-01

67

Fiber dosimetry for radiation therapy validation  

Microsoft Academic Search

Radiation doses used in radiation therapy are calculated during the course of treatment planning. Cross-validation of calculated dose versus received dose is performed mostly in-vitro and may not represent actual therapy doses. In vivo measurements are at best typically limited to a few surface points. Presently, dose is measured primarily with diodes, thermoluminescent or MOSFET dosimeters. Their outer sizes are

I. Saxena; G. Jozsef

2008-01-01

68

Radiation Therapy for Early Stage Lung Cancer  

PubMed Central

Radiation therapy for early stage lung cancer is a promising modality. It has been traditionally used in patients not considered candidates for standard surgical resection. However, its role has been changing rapidly since the introduction of new and advanced technology, especially in tumor tracking, image guidance, and radiation delivery. Stereotactic radiation therapy is one such advancement that has shown excellent local control rates and promising survival in early stage lung cancer. In addition, the toxicity profiles are quite favorable. In addition to stereotactic radiation, advances in brachytherapy techniques have enabled high local control rates in operable patients who receive sublobar resections due to compromised pulmonary function. Isotopes that have been used include iodine-125, palladium-103, and cesium-131. In this review article, the role of radiation therapy in treatment of lung cancer, patient selection, outcomes, toxicity and recent technological advancements are discussed. The radiation therapy techniques described in this article are also being used in the management of locally advanced lung cancers.

Parashar, Bhupesh; Arora, Shruthi; Wernicke, A. Gabriella

2013-01-01

69

[Highly quality-controlled radiation therapy].  

PubMed

Advanced radiation therapy for intracranial disease has focused on set-up accuracy for the past 15 years. However, quality control in the prescribed dose is actually as important as the tumor set-up in radiation therapy. Because of the complexity of the three-dimensional radiation treatment planning system in recent years, the highly quality-controlled prescription of the dose has now been reappraised as the mainstream to improve the treatment outcome of radiation therapy for intracranial disease. The Japanese Committee for Quality Control of Radiation Therapy has developed fundamental requirements such as a QC committee in each hospital, a medical physicist, dosimetrists (QC members), and an external audit. PMID:15853208

Shirato, Hiroki

2005-04-01

70

Acoustic radiation force beam sequence performance for detection and material characterization of atherosclerotic plaques: preclinical, ex vivo results.  

PubMed

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

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

2013-12-01

71

Adenoviral Gene Therapy, Radiation, and Prostate Cancer  

PubMed Central

Viral gene therapy has exceptional potential as a specifically tailored cancer treatment. However, enthusiasm for cancer gene therapy has varied over the years, partly owing to safety concerns after the death of a young volunteer in a clinical trial for a genetic disease. Since this singular tragedy, results from numerous clinical trials over the past 10 years have restored the excellent safety profile of adenoviral vectors. These vectors have been extensively studied in phase I and II trials as intraprostatically administered agents for patients with locally recurrent and high-risk local prostate cancer. Promising therapeutic responses have been reported in several studies with both oncolytic and suicide gene therapy strategies. The additional benefit of combining gene therapy with radiation therapy has also been realized; replicating adenoviruses inhibit DNA repair pathways, resulting in a synergistic sensitization to radiation. Other, nonreplicating suicide gene therapy strategies are also significantly enhanced with radiation. Combined radiation/gene therapy is currently being studied in phase I and II clinical trials and will likely be the first adenoviral gene therapy mechanism to become available to urologists in the clinic. Systemic gene therapy for metastatic disease is also a major goal of the field, and clinical trials are currently under way for hormone-resistant metastatic prostate cancer. Second- and third-generation “re-targeted” viral vectors, currently being developed in the laboratory, are likely to further improve these systemic trials.

Lupold, Shawn E; Rodriguez, Ronald

2005-01-01

72

Plaque Psoriasis  

MedlinePLUS

... Programs Calendar of Events 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 ...

73

Hyperbaric oxygen therapy for radiation myelitis  

SciTech Connect

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

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

1985-12-01

74

Ototoxicity of cisplatin plus standard radiation therapy vs. accelerated radiation therapy in glioblastoma patients  

Microsoft Academic Search

Summary  \\u000a Purpose: To assess the effect of cisplatin (CDDP) plus concurrent radiation therapy on hearing loss. Methods: 451 patients with glioblastoma multiforme (GBM) were randomly assigned after surgery to: Arm A: Carmustine (BCNU) + standard\\u000a radiation therapy (SRT); Arm B: BCNU + accelerated radiation therapy (ART: 160 cGy twice daily for 15 days); Arm C: CDDP +\\u000a BCNU + SRT; or Arm

Nicole E. Marshall; Karla V. Ballman; John C. Michalak; Paula J. Schomberg; Gary V. Burton; Howard M. Sandler; Terrence L. Cascino; Kurt A. Jaeckle; Jan C. Buckner

2006-01-01

75

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

76

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

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

1979-01-01

77

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

78

Radiation Therapy: Additional Treatment Options  

MedlinePLUS

... doctors now know much more about how cancer cells function. New cancer therapies use this information to target cancer cell functions and stop them. Called targeted therapies, they can be more specific in stopping cancer cells from growing and may make other treatments ...

79

New therapeutic strategies in radiation therapy  

SciTech Connect

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

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

1981-04-24

80

Immobilization considerations for proton radiation therapy.  

PubMed

Proton therapy is rapidly developing as a mainstream modality for external beam radiation therapy. This development is largely due to the ability of protons to deposit much of their energy in a region known as the Bragg peak, minimizing the number of treatment fields and hence integral dose delivered to the patient. Immobilization in radiation therapy is a key component in the treatment process allowing for precise delivery of dose to the target volume and this is certainly true in proton therapy. In proton therapy immobilization needs to not only immobilize the patient, placing them in a stable and reproducible position for each treatment, but its impact on the depth dose distribution and range uncertainty must also be considered. The impact of immobilization on range is not a primary factor in X-ray radiation therapy, but it is a governing factor in proton therapy. This contribution describes the immobilization considerations in proton therapy which have been developed at Loma Linda over twenty plus years of clinical operation as a hospital based proton center. PMID:24066953

Wroe, Andrew J; Bush, David A; Slater, Jerry D

2014-06-01

81

Radiation Therapy for Breast Cancer  

MedlinePLUS

... 7852 www.astro.org • www.rtanswers.org TREATING BREAST CANCER Surgery The main curative treatment for breast cancer is ... of the lymph nodes is performed with the breast surgery of choice. Both mastectomy and breast conserving therapy ( ...

82

Radiation therapy alone versus radiation therapy and chemotherapy in the management of Hodgkin's disease.  

PubMed Central

Forty-four patients with histologically proven Hodgkin's disease underwent initial treatment with extended-field radiation therapy. Nineteen of these patients also received combination chemotherapy. For analysis, patients were assigned to three treatment groups: group 1 received radiation therapy only (25 patients); group 2 received combination chemotherapy followed by consolidative (low-dose extended-field) radiation therapy; and group 3 was treated with alternate chemotherapy and radiation therapy using the sandwich technique. The actuarial 5-year disease-free survival rates were 83% (group 1), 83% (group 2), and 100% (group 3). The overall actuarial survival rates were 96% (group 1), 92% (group 2), and 100% (group 3). No factor was identified as being of prognostic value in predicting relapse. We conclude that extended-field radiation therapy delivered in this manner is a safe and effective approach to the initial management of Hodgkin's disease.

Glenn, L. D.; Kumar, P. P.

1990-01-01

83

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

84

Radiation Therapy for Skin Cancer  

MedlinePLUS

... also receive other treatments like chemotherapy. Before treatment begins, ask your doctor about possible side eff ects ... cancer, and it is very curable. These cancers begin in the outer layer of skin (epidermis ). Radiation ...

85

Intracranial aneurysm following cranial radiation therapy.  

PubMed

We report herein a case of a radiation-induced aneurysm. A 69-year-old woman presented with subarachnoid hemorrhage. Eight years previously, she had undergone cranial radiation therapy (total dose of 59.4 Gy) as adjuvant therapy after surgical resection for a chondrosarcoma that was destroying her sphenoid sinus. The patient underwent catheter angiography, which revealed an aneurysm of the anterior communicating artery and luminal narrowing and irregularity in the petrous and lacerum segments of the right internal carotid artery. We attempted surgical clipping of the aneurysm, but there was repeated bleeding. Finally the aneurysm was treated with endovascular trapping. Potentially fatal bleeding also occurred from her internal carotid artery, which had also been irradiated during the previous cranial radiation therapy. We stopped the bleeding with endovascular coil embolization. Because of diffuse vascular changes of the cerebral vessels within irradiated fields, special attention must be paid to their treatment. PMID:23346546

Huh, Won; Bang, Jae Seung; Oh, Chang Wan; Kwon, O-Ki; Hwang, Gyojun

2012-12-01

86

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

87

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

88

Fiber dosimetry for radiation therapy validation  

NASA Astrophysics Data System (ADS)

Radiation doses used in radiation therapy are calculated during the course of treatment planning. Cross-validation of calculated dose versus received dose is performed mostly in-vitro and may not represent actual therapy doses. In vivo measurements are at best typically limited to a few surface points. Presently, dose is measured primarily with diodes, thermoluminescent or MOSFET dosimeters. Their outer sizes are in the range of 3 mm, which are unpractical for in vivo internal use, in particular for interstitial or intracavital brachytherapy. In addition, diode and MOSFET sensors are individually tethered to cables and are therefore inconvenient for making multiple point measurements. Feasibility of multiple point radiation dosimetry using luminescent optical fibers for in vivo dosimetry during radiation therapy is described that overcomes these difficulties. The spectral response of a candidate rare-earth doped optical fiber dosimetric probe is reported, having 0.5 rads/cm sensitivity. This sensor capability would enable continuous radiation monitoring of dose and dose rate during therapy at multiple locations along the sensor fiber.

Saxena, I.; Jozsef, G.

2008-03-01

89

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

Code of Federal Regulations, 2013 CFR

... Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy and radioactive isotope therapy, and materials and the services of technicians administering the treatment. [51 FR 41339, Nov. 14,...

2013-10-01

90

Process of Coping with Radiation Therapy.  

ERIC Educational Resources Information Center

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

Johnson, Jean E.; And Others

1989-01-01

91

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).

92

Stereotactic body radiation therapy delivery validation  

NASA Astrophysics Data System (ADS)

This work describes the use of a motion phantom and 1D, 2D, and 3D ion chamber, EBT3 film, electronic portal imaging device (EPID) and FXG gel measurements for dosimetric validation of a stereotactic ablative radiation therapy (SBRT) technique in our clinic. Results show good agreement between the measurements and calculated treatment plan dose.

Olding, T.; Garcia, L.; Alexander, K.; Schreiner, L. J.; Joshi, C.

2013-06-01

93

Quality assurance in radiation therapy: physics efforts.  

PubMed

During the last two years, several important documents on quality assurance in radiation therapy have been published. In 1981 the Committee on Radiation Oncology Studies, in a report to the Director of the National Cancer Institute, outlined criteria for multidisciplinary cancer management, including technical standards in radiation therapy. In March 1983, a task group of the American Association of Physicists in Medicine (AAPM) submitted a document for review and publication on "The Physical Aspects of Quality Assurance in Radiation Therapy". This document addresses quality assurance problems related to: 1. treatment machines; 2. measurement equipment; 3. treatment planning; 4. treatment verification; 5. brachytherapy; and 6. radiation safety. One chapter in this latter document discusses the problem of estimating the uncertainty in dose delivered to a patient. The contributions to this uncertainty are analyzed and separated into dosimetric and spatial uncertainties. The dosimetric uncertainties resulting from the central axis calibration and treatment planning amount to about 5% at the 95% confidence level in an optimal situation. The spatial uncertainties resulting from machine alignment problems combined with patient set-up and organ motion may be about 8 mm to 10 mm, corresponding to two standard deviations. An example of how the spatial uncertainty translates into a dose uncertainty for a three-field esophageal plan is discussed. PMID:6735791

Svensson, G K

1984-06-01

94

Radiation therapy for Hodgkin lymphoma.  

PubMed

The long-term cardiac complications of radio(chemo)therapy for Hodgkin lymphoma include coronary artery disease, cardiac arrhythmias, valvular disease, pericardial disease, cardiomyopathy and heart failure. The extent of myocardial damage after radiotherapy is dependent on the dose, the volume and the technique of chest irradiation. Also, patient-specific factors, such as the age of the patient at the time of treatment and the presence of classical cardiac risk factors are supposed to be important. The relative risk of cardiovascular events is estimated to be 2 to 7 times higher than the general population. The patient's clinical picture can vary from asymptomatic to an acute presentation of end-stage coronary artery or valvular disease. PMID:24783474

Everaert, Bert R; Van den Heuvel, Paul

2014-04-01

95

Newer Radiation Therapy Treats Prostate Cancer More Quickly  

MedlinePLUS

... page, please enable JavaScript. Newer Radiation Therapy Treats Prostate Cancer More Quickly: Study But researchers found less ... Preidt Wednesday, March 12, 2014 Related MedlinePlus Pages Prostate Cancer Radiation Therapy WEDNESDAY, March 12, 2014 (HealthDay ...

96

Guidelines for the Provision of Radiation Therapy Services.  

National Technical Information Service (NTIS)

Findings and conclusions of the Radiation Therapy Guidelines Committee of the Metropolitan Health Planning Corporation (MHPC) Cleveland, Ohio, pertaining to radiation therapy resources and services in the 12-county Northeast Ohio Regional Medical Program ...

1972-01-01

97

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2010 CFR

A radiation therapy simulation system is a fluoroscopic or radiographic x-ray system intended for use in localizing the volume to be exposed during radiation therapy and confirming the position and size of the therapeutic irradiation field...

2014-04-01

98

Radiation Therapy -- What It Is, How It Helps  

MedlinePLUS

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

99

Effectiveness of Conventional Drug Therapy of Plaque Psoriasis in the Context of Consensus Guidelines: A Prospective Observational Study in 150 Patients  

PubMed Central

Background Evidence for superior outcome by adhering to therapy guidelines is imperative to their acceptance and adaptation for the optimal management of disease variants. Objective Comparative study of prospective outcomes in simultaneous consideration of independent variables in groups of 150 patients of plaque psoriasis either treated adhering to or in digression of standard guidelines. Methods The psoriasis area severity index (PASI) and the dermatology life quality index (DLQI), prior to and after three months of uninterrupted therapy were examined in treatment groups among 150 patients. Recovery rates of 75% or more in PASI were compared. Independent variables were also examined for their bearing on the outcome. Results The vast majority was early onset disease phenotype. All three treatment regimens when administered in adherence to the guidelines yielded significantly superior rates of defined recovery both in PASI and DLQI. Compromise of the therapeutic outcome appeared in high stress profiles, obesity, female sex and alcohol, tobacco or smoking habit. Conclusion Conventional drug therapy of plaque psoriasis yields superior outcome by adhering to the consensus guidelines. Psychiatric address to stress must be integral and special considerations for phenotypic/syndromic variants is emphasized for effective therapy of psoriasis.

Gupta, Ashok Kumar; Pandey, Shyam Sunder

2013-01-01

100

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

101

Treatment planning for conformal proton radiation therapy.  

PubMed

Clinical results from various trials have demonstrated the viability of protons in radiation therapy and radiosurgery. This has motivated a few large medical centers to design and build expensive hospital based proton facilities based proton facilities (current cost estimates for a proton facility is around 100 million US dollars). Until this development proton therapy was done using retrofitted equipment originally designed for nuclear experiments. There are presently only three active proton therapy centers in the United States, 22 worldwide. However, more centers are under construction and being proposed in the US and abroad. The important difference between proton and x-ray therapy is in the dose distribution. X-rays deposit most of their dose at shallow depths of a few centimeters with a gradual decay with depth in the patient. Protons deliver most of their dose in the Bragg peak, which can be delivered at most clinically required depths followed by a sharp fall-off. This sharp falloff makes protons sensitive to variations in treatment depths within patients. Treatment planning incorporates all the knowledge of protons into a process, which allows patients to be treated accurately and reliably. This process includes patient immobilization, imaging, targeting, and modeling of planned dose distributions. Although the principles are similar to x-ray therapy some significant differences exist in the planning process, which described in this paper. Target dose conformality has recently taken on much momentum with the advent of intensity modulated radiation therapy (IMRT) with photon beams. Proton treatments provide a viable alternative to IMRT because they are inherently conformal avoiding normal tissue while irradiating the intended targets. Proton therapy will soon bring conformality to a new high with the development of intensity modulated proton therapy (IMPT). Future challenges include keeping the cost down, increasing access to conventional proton therapy as well as the clinical implementation of IMPT. Computing advances are making Monte Carlo techniques more accessible to treatment planning for all modalities including proton therapy. This technique will allow complex delivery configurations to be properly modeled in a clinical setting. PMID:14529304

Bussière, Mark R; Adams, Judith A

2003-10-01

102

Androgen deprivation with radiation therapy compared with radiation therapy alone for locally advanced prostatic carcinoma: a randomized comparative trial of the radiation therapy oncology group  

Microsoft Academic Search

ObjectivesAndrogen deprivation therapy before and during radiation therapy could, by reducing tumor volume, increase local tumor control, disease-free survival, and overall survival in patients with locally advanced adenocarcinomas of the prostate.

Miljenko V. Pilepich; William T. Sause; William U. Shipley; John M. Krall; Colleen A. Lawton; David Grignon; Muhyi Al-Sarraf; Ross A. Abrams; Richard Caplan; Madhu J. John; Marvin Rotman; James D. Cox; R. L. Scotte Doggett; Philip Rubin; Mark S. Soloway

1995-01-01

103

Pros and cons of antioxidant use during radiation therapy  

Microsoft Academic Search

Radiation therapy is one of the major treatment modalities in the management of human cancer. While impressive progress like more accurate dosimetry and more precise methods of radiation targeting to tumor tissue has been made, the value of radiation therapy in tumor control may have reached a plateau. At present, two opposing hypotheses regarding the use of antioxidants during radiation

K. N Prasad; W. C Cole; B Kumar; K Che Prasad

2002-01-01

104

Neuralgic amyotrophy in association with radiation therapy for Hodgkin's disease  

SciTech Connect

We describe 4 patients with Hodgkin's disease who developed neuralgic amyotrophy in the setting of radiation therapy. In contrast to tumor progression or radiation plexopathy, the symptom onset was abrupt and occurred within days to weeks of receiving radiation treatments. There is an association between Hodgkin's disease, radiation therapy, and neuralgic amyotrophy.

Malow, B.A.; Dawson, D.M. (Brigham and Women's Hospital, Boston, MA (USA))

1991-03-01

105

Health systems analysis: radiation therapy services  

SciTech Connect

A plan for the distribution of radiation therapy services within Health Services Area I (HSA I) is presented in this report. Four problems concerning health status or health system aspects of megavoltage radiation therapy services within HSA I are identified: (1) the health status of the populations residing in the area of Lexington, Winchester, Louisa and Fluvanna with respect to cancer; (2) the failure of Rockingham Memorial Hospital to meet minimum volume standards and the projection of a failure to meet this minimum volume standard by 1986; (3) the absence of the specialities of hematology or medical oncology on the medical staff of the hospital at Rockingham; and (4) a lack of registered nurses/licensed practical nurses and a docimetrist at Winchester Memorial Hospital, which could impact on the quality of care. An additional area of concern is the increase in charges on the linear accelerator at the University of Virginia. Preliminary findings do not indicate that radiation therapy services within HSA I are inappropriate. Recommendations for addressing problem areas are proposed.

Not Available

1981-10-01

106

Intensity-Modulated Radiation Therapy, Proton Therapy, or Conformal Radiation Therapy and Morbidity and Disease Control in Localized Prostate Cancer  

PubMed Central

Context There has been rapid adoption of newer radiation treatments such as intensitymodulated radiation therapy (IMRT) and proton therapy despite greater cost and limited demonstrated benefit compared with previous technologies. Objective To determine the comparative morbidity and disease control of IMRT, proton therapy, and conformal radiation therapy for primary prostate cancer treatment. Design, Setting, and Patients Population-based study using Surveillance, Epidemiology, and End Results–Medicare-linked data from 2000 through 2009 for patients with nonmetastatic prostate cancer. Main Outcome Measures Rates of gastrointestinal and urinary morbidity, erectile dysfunction, hip fractures, and additional cancer therapy. Results Use of IMRT vs conformal radiation therapy increased from 0.15% in 2000 to 95.9% in 2008. In propensity score–adjusted analyses (N=12 976), men who received IMRT vs conformal radiation therapy were less likely to receive a diagnosis of gastrointestinal morbidities (absolute risk, 13.4 vs 14.7 per 100 person-years; relative risk [RR], 0.91; 95% CI, 0.86–0.96) and hip fractures (absolute risk, 0.8 vs 1.0 per 100 person-years; RR, 0.78; 95% CI, 0.65–0.93) but more likely to receive a diagnosis of erectile dysfunction (absolute risk, 5.9 vs 5.3 per 100 person-years; RR, 1.12; 95% CI, 1.03–1.20). Intensitymodulated radiation therapy patients were less likely to receive additional cancer therapy (absolute risk, 2.5 vs 3.1 per 100 person-years; RR, 0.81; 95% CI, 0.73–0.89). In a propensity score–matched comparison between IMRT and proton therapy (n=1368), IMRT patients had a lower rate of gastrointestinal morbidity (absolute risk, 12.2 vs 17.8 per 100 person-years; RR, 0.66; 95% CI, 0.55–0.79). There were no significant differences in rates of other morbidities or additional therapies between IMRT and proton therapy. Conclusions Among patients with nonmetastatic prostate cancer, the use of IMRT compared with conformal radiation therapy was associated with less gastrointestinal morbidity and fewer hip fractures but more erectile dysfunction; IMRT compared with proton therapy was associated with less gastrointestinal morbidity.

Sheets, Nathan C.; Goldin, Gregg H.; Meyer, Anne-Marie; Wu, Yang; Chang, YunKyung; Sturmer, Til; Holmes, Jordan A.; Reeve, Bryce B.; Godley, Paul A.; Carpenter, William R.; Chen, Ronald C.

2013-01-01

107

Automatic field shaping for conformal radiation therapy.  

PubMed

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

Ayyangar, K

1994-04-01

108

[Plaque indices].  

PubMed

The objective quantitative evaluation of the extent of plaques is necessary for epidemiologic studies and for the estimation of the effects of various cleaning methods and agents. Numerous indices have been elaborated for this purpose. Relation planimetry is used for the detection and exact evaluation of small differences. The surfaces are measured with a compensating planimeter, the slides to be evaluated being projected on a white sheet by means of a microfilm reader. In this way, the plaque covered surfaces are determined as percentages of the total surfaces. PMID:283608

Kötzschke, R

1978-11-01

109

Recall radiation dermatitis by sorafenib following stereotactic body radiation therapy  

PubMed Central

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

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

2014-01-01

110

Radiation Therapy for Locally Recurrent Breast Cancer  

PubMed Central

Approximately one-third of all breast cancer patients experience local recurrence of their tumor after initial treatment. As initial treatment often employs the use of radiation therapy (RT), the standard of care for local breast cancer recurrence after initial breast conserving therapy has traditionally been surgical intervention with mastectomy. However, recent attempts to preserve the intact breast after recurrence with local excision have revealed a potential need for RT in addition to repeat breast conserving surgery as rates of local failure with resection alone remain high. Additionally, local recurrence following initial mastectomy and chest wall RT can be treated with reirradiation to increase local control. Repeating RT, however, in a previously irradiated area, is a complex treatment strategy, as the clinician must carefully balance maximizing treatment effectiveness while minimizing treatment-related toxicity. As a result, physicians have been hesitant to treat recurrent disease with repeat RT with limited data. Results from the current literature are promising and current clinical trials are underway to explore reirradiation modalities which will provide additional information on treatment-related toxicity and outcomes. This paper will review the current literature on repeat radiation therapy for locally recurrent breast cancer.

Siglin, Joshua; Champ, Colin E.; Vakhnenko, Yelena; Anne, Pramila R.; Simone, Nicole L.

2012-01-01

111

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

112

X3D IN RADIATION THERAPY PROCEDURE PLANNING  

Microsoft Academic Search

Radiation therapy, an increasingly available and effective cancer treatment solution, involves sophisticated machinery as well as careful planning. Interactive 3D simulations combined with accurate 3D patient specific data can improve the planning process saving time and resources in generating the optimal treatment plan. We illustrate the potential of X3D in radiation therapy, specifically radiation treatment planning. Embedding patient specific data

Felix G. Hamza-Lup; Ivan Sopin; Dan Lipsa; Omar Zeidan

113

HYPERBARIC OXYGEN THERAPY FOR RADIATION INDUCED HEMORRHAGIC CYSTITIS  

Microsoft Academic Search

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

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

1999-01-01

114

Mini-TEPCs for radiation therapy.  

PubMed

A mini-tissue-equivalent proportional-counter (TEPC) has been constructed to study the possibility to manufacture mini-counters without field-shaping tubes for radiation therapy. The mini-TEPC can be assembled with and without field-shaping tubes. It can be equipped with a mini-alpha source for a precise lineal energy calibration. After the positive conclusions of this study, a slim TEPC has been designed and constructed. The slim TEPC has an external diameter of only 2.7 mm. It has been tested with therapeutic proton beams and gamma ray sources. PMID:15103064

De Nardo, L; Cesari, V; Donà, G; Magrin, G; Colautti, P; Conte, V; Tornielli, G

2004-01-01

115

[Postoperative radiation therapy in lung carcinom].  

PubMed

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

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

2014-05-21

116

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.

Clerici, Elena; Comito, Tiziana

2014-01-01

117

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.

Meyer, Jeffrey J.; Willett, Christopher G.

2007-01-01

118

Automatic Organ Localization for Adaptive Radiation Therapy for Prostate Cancer.  

National Technical Information Service (NTIS)

The goal of this research is to develop automated methods to analyze daily CT scans taken during prostate therapy, in order to make adaptive radiation therapy (ART) more effective and readily implemented. The central technique is deformable image registra...

S. C. Joshi M. Foskey B. Davis

2005-01-01

119

Intensity-modulated radiation therapy in gynecologic malignancies  

Microsoft Academic Search

Opinion statement  Radiation therapy occupies an important role in the treatment of gynecologic malignancies. Unfortunately, traditional approaches\\u000a result in the irradiation of large volumes of normal tissues exposing patients to many toxicities and precluding dose escalation\\u000a in select patients. A novel approach to the planning and delivery of radiation therapy, known as intensity-modulated radiation\\u000a therapy (IMRT), has been introduced. Unlike conventional

Joseph K. Salama; John C. Roeske; Neil Mehta; Arno J. Mundt

2004-01-01

120

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

121

Positron emission tomography-computed tomography protocols for radiation therapy planning and therapy response assessment.  

PubMed

This article covers positron emission tomography-computed tomography (PET-CT) scan protocols for radiation therapy planning purposes and therapy response assessment. For radiation therapy planning PET-CT scans, protocols used will depend on the intended use of the PET-CT images in the radiation therapy planning. In general scans are performed on a flat radiation therapy pallet with the patient in the treatment position or closely approximating the treatment position. PET-CT protocols used in radiation therapy planning are typically otherwise very similar to diagnostic protocols. An important component in PET-CT imaging performed for therapy monitoring and assessment is consistency in patient preparation, image acquisition, and imaging processing of the baseline scan and subsequent therapy assessment scans. PMID:21147374

Shreve, Paul; Swanston, Nancy M; Faasse, Todd

2010-12-01

122

How Should I Care for Myself During Radiation Therapy?  

MedlinePLUS

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

123

Intraoperative radiation therapy of pancreatic carcinoma: a report of RTOG-8505. Radiation Therapy Oncology Group.  

PubMed

The Radiation Therapy Oncology Group in 1985 began a study of IORT plus external beam radiation therapy for patients with locally unresected, non-metastatic pancreatic cancer. Patients were treated with a combination of 2000 cGy of IORT and postoperative external beam radiation therapy to 5040 cGy in combination with IV 5-FU (500 mg/m2/day on the first 3 days of the external beam treatment). As patients were registered on study prior to exploration, it was expected that a number of patients would be excluded from further analysis at the time of surgery. Eighty-six patients were entered on study through 6/1/88 and analyzed through 4/90. Fifty-one patients were fully analyzable. Median survival time of the 51 patients was 9 months with an 18-month actuarial survival rate of 9%. Local control could not be adequately evaluated in this multi-institutional study. Major postoperative complications were not excessive and occurred in 12% of patients. Two patients had major late morbidity leading to death, one from duodenal bleeding and the second from biliary obstruction. Although this study does demonstrate the feasibility of IORT in a multi-institutional setting, it does not demonstrate any advantage of IORT over conventional therapy for this disease. PMID:1657839

Tepper, J E; Noyes, D; Krall, J M; Sause, W T; Wolkov, H B; Dobelbower, R R; Thomson, J; Owens, J; Hanks, G E

1991-10-01

124

Precise positioning of patients for radiation therapy.  

PubMed

We have developed a number of immobilization schemes which permit precise daily positioning of patients for radiation therapy. Pretreatment and post-treatment radiographs have been taken with the patient in the treatment position and analyzed to determine the amount of intratreatment movement. Studies of patients in the supine, seated and decubitus positions indicate mean movements of less than 1 mm with a standard deviation of less than 1mm. Patients immobilized in the seated position with a bite block and a mask have a mean movement of about 0.5 mm +/- 0.3 mm (s.d.), and patients immobilized in the supine position with their necks hyperextended for submental therapy evidence a mean movement of about 1.4 mm +/- 0.9 mm (s.d.). With the exception of those used for the decubitus position, the immobilization devices are simply fabricated out of thermoplastic casting materials readily available from orthopedic supply houses. A study of day-to-day reproducibility of patient position using laser alignment and pretreatment radiographs for final verification of position indicates that the initial laser alignment can be used to position a patient within 2.2 mm +/- 1.4 mm (s.d.) of the intended position. These results indicate that rigid immobilization devices can improve the precision of radiotherapy, which would be advantageous with respect to both tumor and normal tissue coverage in certain situations. PMID:6282792

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

1982-02-01

125

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

126

Hyperbaric Oxygen Therapy for Radiation-induced Optic Neuropathy  

Microsoft Academic Search

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

Richard L Levy; Neil R Miller

127

Selective use of adjuvant radiation therapy in resectable colorectal adenocarcinoma  

Microsoft Academic Search

Colorectal cancer recurs within the operative field in 10-20 per cent of patients undergoing potentially curative surgery. In certain subgroups, the recurrence rate is 20-50 per cent. There are some data to suggest either preoperative or postoperative radiation therapy as an adjuvant to potentially curative surgery can reduce the local operative failure rate. However, since radiation therapy has significant side

A. M. Cohen; L. L. Gunderson; C. E. Welch

2009-01-01

128

Stereotactic body radiation therapy: a comprehensive review.  

PubMed

Stereotactic body radiation therapy (SBRT) is a novel technique that takes advantage of the technologic advancements in image guidance and radiation dose delivery to direct ablative doses to tumors with acceptable toxicity that was not previously achievable with conventional techniques. SBRT requires a high degree of confidence in tumor location provided by high quality diagnostic and near real-time imaging studies for accurate treatment delivery and precise assessment of physiologic tumor motion. In addition, stringent dosimetric parameters must be applied, paying close attention to the spatial arrangement of functional subunits in the adjacent normal tissues, to optimize clinical outcomes. Phase I/II trials for tumors of the lung, liver, spine, pancreas, kidney, and prostate provide evidence that the potent doses delivered with SBRT may provide results that rival surgery while avoiding the typical morbidities associated with that invasive approach. Further clinical study in the form of multi-institutional Phase II trials is currently underway, and ultimately collaborative efforts on a national level to support Phase III trials will be necessary, to firmly establish SBRT as a comparable noninvasive alternative to surgery. PMID:18091059

Chang, Brian K; Timmerman, Robert D

2007-12-01

129

Diagnosis of delayed cerebral radiation necrosis following proton beam therapy  

SciTech Connect

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 (a mass lesion). Various facets of radiation injury are discussed, including pathogenesis, risk factors, diagnosis, and therapy.

Kaufman, M.; Swartz, B.E.; Mandelkern, M.; Ropchan, J.; Gee, M.; Blahd, W.H. (Wadsworth Veterans Administration Medical Center, Los Angeles, CA (USA))

1990-04-01

130

Intensity-modulated radiation therapy: emerging cancer treatment technology  

Microsoft Academic Search

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

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

2005-01-01

131

Technological Advances in Radiation Therapy for Prostate Cancer  

Microsoft Academic Search

Radiation therapy (RT) for prostate cancer has made huge strides over the past two decades. The addition of image guidance\\u000a has allowed radiation oncologists to ensure accurate delivery of increasingly precise radiation treatment plans using newer\\u000a conformal therapy methods such as three-dimensional conformal RT, intensity-modulated RT, and proton beam RT. Regardless of\\u000a the specific treatment technique, patients can depend on

Mehee Choi; Arthur Y. Hung

2010-01-01

132

Recurrent spontaneous pneumothorax after radiation therapy to the thorax  

Microsoft Academic Search

Two patients who received radiation therapy to the thorax and who developed recurrent spontaneous pneumothoraces are presented. Patients with recurrent pneumothoraces secondary to radiation have not been described previously. Pleural changes secondary to radiation may contribute significantly to the complicated clinical course of these patients.

T. W. Jr. Twiford; J. Zornoza; H. I. Libshitz

1978-01-01

133

Radiation Therapy for Chloroma (Granulocytic Sarcoma)  

SciTech Connect

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

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

2012-04-01

134

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

135

On probabilistically defined margins in radiation therapy  

NASA Astrophysics Data System (ADS)

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

Papiez, Lech; Langer, Mark

2006-08-01

136

Compensating for heterogeneities in proton radiation therapy.  

PubMed

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

Urie, M; Goitein, M; Wagner, M

1984-05-01

137

Adaptive Radiation Therapy for Prostate Cancer  

PubMed Central

Adaptive radiotherapy has been introduced to manage an individual's treatment by, including patient-specific treatment variation identified and quantified during the course of radiotherapy in the treatment planning and delivering optimization. Early studies have demonstrated that this technique could significantly improve the therapeutic ratio by safely reducing the large target margin that has to be used in conventional radiotherapy for prostate cancer treatment. Clinical application of off-line image-guided adaptive radiotherapy for prostate cancer has demonstrated encouraging clinical outcome. Long-term clinical follow-up has shown significant improvement in terms of tumor control and low toxicity profile, emphasizing the beneficial effect of image-guidance and adaptive treatment. Continuous development in adaptive radiotherapy has made possible additional increases in target dose by further reducing target margin when using online image-guided adaptive intensity-modulated radiation therapy. However, clinical implementation of new techniques should be explored cautiously and should include a comprehensive management strategy to address uncertainties in target definition and delineation in the preclinical implementation studies.

Ghilezan, Michel; Yan, Di; Martinez, Alvaro

2013-01-01

138

Thymic cysts following radiation therapy for Hodgkin disease  

SciTech Connect

In 3 patients, benign thymic cycsts developed following radiation therapy for Hodgkin disease. Autopsy or surgical specimens provided a diagnosis in all 3 cases; computed tomographic (CT) scans obtained in two of the patients provided a preoperative diagnosis. The etiology of these cysts is uncertain; they may arise following successful radiation treatment of Hodgkin disease involving the thymus. When an anterior mediastinal mass develops in a patient with Hodgkin disease following radiation therapy, careful evaluation to exclude a benign process is indicated prior to initiating additional therapy.

Baron, R.L.; Sagel, S.S.; Baglan, R.J.

1981-12-01

139

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

140

The Impact of the Myeloid Response to Radiation Therapy  

PubMed Central

Radiation therapy is showing potential as a partner for immunotherapies in preclinical cancer models and early clinical studies. As has been discussed elsewhere, radiation provides debulking, antigen and adjuvant release, and inflammatory targeting of effector cells to the treatment site, thereby assisting multiple critical checkpoints in antitumor adaptive immunity. Adaptive immunity is terminated by inflammatory resolution, an active process which ensures that inflammatory damage is repaired and tissue function is restored. We discuss how radiation therapy similarly triggers inflammation followed by repair, the consequences to adaptive immune responses in the treatment site, and how the myeloid response to radiation may impact immunotherapies designed to improve control of residual cancer cells.

Gough, Michael J.; Young, Kristina; Crittenden, Marka

2013-01-01

141

21 CFR 892.5750 - Radionuclide radiation therapy system.  

... 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

142

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

143

21 CFR 892.5300 - Medical neutron 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 § 892.5300 Medical neutron radiation therapy system. (a)...

2011-04-01

144

21 CFR 892.5300 - Medical neutron radiation therapy system.  

... 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

145

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

146

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

147

Utilizing Problem Structure in Optimization of Radiation Therapy.  

National Technical Information Service (NTIS)

In this thesis, optimization approaches for intensity-modulated radiation therapy are developed and evaluated with focus on numerical efficiency and treatment delivery aspects. The first two papers deal with strategies for solving fluence map optimization...

F. Carlsson

2008-01-01

148

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

149

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

150

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

151

Oral and maxillofacial side effects of radiation therapy on children.  

PubMed

Radiation therapy of the head and neck frequently results in serious and sometimes unavoidable changes to orofacial structures, particularly for children. Acute and chronic complications have a great impact on their oral function and quality of life. This paper provides an overview of the side effects of radiation therapy on children's oral and dental tissues, and highlights appropriate preventive guidelines and management strategies to minimize these complications. PMID:17439713

Otmani, Naima

2007-04-01

152

CLINICAL DECISION-SUPPORT SYSTEMS IN RADIATION THERAPY  

Microsoft Academic Search

Computers have been used in radiation therapy since the early 1960s to perform dose calculations. In the last decade, researchers have developed computer-based clinical decision-support systems for assisting in different decision-making tasks in radiation therapy. This paper reviews eleven prototype systems developed for target volume delineation, treatment planning, treatment plan evaluation, and treatment machine diagnosis. The advent of three-dimensional (3D)

NILESH L. JAIN; MICHAEL G. KAHN

1993-01-01

153

Selective use of adjuvant radiation therapy in resectable colorectal adenocarcinoma  

Microsoft Academic Search

Colorectal cancer recurs within the operative field in 10–20 per cent of patients undergoing potentially curative surgery.\\u000a In certain subgroups, the recurrence rate is 20–50 per cent. There are some data to suggest either preoperative or postoperative\\u000a radiation therapy as an adjuvant to potentially curative surgery can reduce the local operative failure rate. However, since\\u000a radiation therapy has significant side

Alfred M. Cohen; Leonard L. Gunderson; Claude E. Welch

1981-01-01

154

Thyroid neoplasia following radiation therapy for Hodgkin's lymphoma  

SciTech Connect

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

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

1987-06-01

155

Radiation therapy of carcinoma of the extrahepatic bile ducts  

SciTech Connect

Carcinoma of the extrahepatic bile ducts was treated in 25 patients by radiation therapy between 1974 and 1981. Seventeen patients were men and eight were women, and the average age was 59.2 years. Cobalt-60 beam or 10 MV x ray was used for radiation therapy, with the total dose ranging from 10 Gy to 60 Gy. Twenty-one patients received 40 Gy or more. Twenty-two patients underwent surgical procedures such as percutaneous transhepatic drainage or T-tube drainage before radiation therapy. Total bilirubin level decreased after radiation therapy in 21 patients. Side effects included loss of appetite, nausea, vomiting, general fatigue, and duodenal ulcer. The mean survival of all patients was 9.2 months after completion of radiation therapy. The longest survival has been for 6.5 years, and the patient is alive and well as of this writing. Radiation therapy proved effective in treatment of carcinoma of the extrahepatic bile ducts in terms of palliation and prognosis.

Hishikawa, Y.; Shimada, T.; Miura, T.; Imajyo, Y.

1983-03-01

156

Radiation therapy: model standards for determination of need  

Microsoft Academic Search

Contents: Health planning process; Health care requirements (model for projecting need for megavoltage radiation therapy); Operational objectives (manpower, megavoltage therapy and treatment planning equipment, support services, management and evaluation of patient care, organization and administration); Compliance with other standards imposed by law; Financial feasibility and capability; Reasonableness of expenditures and costs; Relative merit; Environmental impact.

L. G. Lagasse; T. B. Devins

1982-01-01

157

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

158

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

PubMed Central

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_R, Adnexa_L, Prostate, SeminalVesc, PenileBulb, Femur_R, and Femur_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.; Barthold, H. Joseph; O'Meara, Elizabeth; Bosch, Walter R.; El Naqa, Issam; Al-Lozi, Rawan; Rosenthal, Seth A.; Lawton, Colleen; Lee, W. Robert; Sandler, Howard; Zietman, Anthony; Myerson, Robert; Dawson, Laura A.; Willett, Christopher; Kachnic, Lisa A.; Jhingran, Anuja; Portelance, Lorraine; Ryu, Janice; Small, William; Gaffney, David; Viswanathan, Akila N.; Michalski, Jeff M.

2012-01-01

159

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

160

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

SciTech Connect

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

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

2012-07-01

161

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

162

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

163

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

164

Arterial Occlusive Disease Complicating Radiation Therapy of Cervical Cancer  

PubMed Central

Radiation-induced arterial disease is caused by significant atherosclerosis in the circumjacent vessels being irradiated. Even though this has been recognized as survival of cancer patients treated with radiotherapy improves, it is a problem that is often under-reported. We present a case of chronic thromboembolic occlusion of right common iliac artery in a 53-year-old woman who was treated with radiation therapy for cervical cancer 13 years ago. We initially performed percutaneous transluminal angioplasty with thrombolytic therapy, but had to cease thrombolytic therapy due to upper gastrointestinal bleeding of Dieulafoy's lesion, nevertheless, achieved good results after revascularization by Fogarty embolectomy.

Won, Ki-Bum; Kim, Byeong-Keuk; Ko, Young-Guk; Hong, Myeong-Ki; Jang, Yangsoo

2012-01-01

165

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

166

Phantosmia during radiation therapy: a report of 2 cases.  

PubMed

Phantosmia is an infrequently reported and poorly understood qualitative olfactory disorder characterized by the perception of a frequently unpleasant odor in the absence of an odorant stimulus. Peripheral phantosmia is hypothesized to involve abnormally active olfactory receptor neurons while central phantosmia is theorized to be the result of hyperactive neurons in the cortex. The authors present a case report that describes 2 patients with incomparable tumors and radiation fields who both experienced phantosmia featuring a halitosis-like odor during their courses of radiation therapy. Both the 6-year-old with diffuse intrinsic pontine glioma and the 15-year-old with World Health Organization grade II-III astrocytoma in the bifrontal lobes experienced significant distress and decreased quality of life during treatment because of the phantosmia, which resolved after completion of radiation therapy. To the best of the authors' knowledge, these are the first descriptions of phantosmia during focal or whole-brain radiation therapy. PMID:22805250

Yang, Joanna C; Khakoo, Yasmin; Lightner, Donita D; Wolden, Suzanne L

2013-06-01

167

Planning and delivery of intensity-modulated radiation therapy  

SciTech Connect

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

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

2008-12-15

168

Postmastectomy Radiation Therapy: An Overview for the Practicing Surgeon  

PubMed Central

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

Jagsi, Reshma

2013-01-01

169

Stereotactic body radiation therapy: scope of the literature.  

PubMed

Stereotactic body radiation therapy (SBRT) is derived from the techniques of stereotactic radiosurgery used to treat lesions in the brain and spine. It combines multiple finely collimated radiation beams and stereotaxy to deliver a high dose of radiation to an extracranial target in the body in a single dose or a few fractions. This review provides a broad overview of the current state of SBRT for solid malignant tumors. Reviewers identified a total of 124 relevant studies. To our knowledge, no published comparative studies address the relative effectiveness and safety of SBRT versus other forms of external-beam radiation therapy. Stereotactic body radiation therapy seems to be widely diffused as a treatment of various types of cancer, although most studies have focused only on its use for treating thoracic tumors. Comparative studies are needed to provide evidence that the theoretical advantages of SBRT over other radiation therapies actually occur in the clinical setting; this area is currently being studied in only 1 small trial. PMID:21536933

Tipton, Kelley; Launders, Jason H; Inamdar, Rohit; Miyamoto, Curtis; Schoelles, Karen

2011-06-01

170

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

SciTech Connect

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

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

1987-12-01

171

Radiation-induced bystander signalling in cancer therapy  

PubMed Central

Our understanding of how radiation kills normal and tumour cells has been based on an intimate knowledge of the direct induction of DNA damage and its cellular consequences. What has become clear is that, as well as responses to direct DNA damage, cell–cell signalling — known as the bystander effect — mediated through gap junctions and inflammatory responses may have an important role in the response of cells and tissues to radiation exposure and also chemotherapy agents. This Review outlines the key aspects of radiation-induced intercellular signalling and assesses its relevance for existing and future radiation-based therapies.

Prise, Kevin M.; O'Sullivan, Joe M.

2010-01-01

172

Radiation Research: Tumour Biology and Therapy.  

National Technical Information Service (NTIS)

Papers in Session D of these proceedings are grouped under the following headings: (1) effects on tumors, cell survival, and growth delay; (2) tumor and normal tissue proliferation kinetics; effects on normal tissues; (3) high LET radiation; (4) modificat...

J. J. Broerse G. W. Barendsen H. B. Kal A. J. van der Kogel

1983-01-01

173

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.

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

2014-01-01

174

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.

Bortfeld, T; Jeraj, R

2011-01-01

175

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

176

Transformation of lymphoma to amyloidoma following radiation therapy  

SciTech Connect

A 62-year-old man presented with a localized upper-extremity small cell lymphoma with plasmacytoid features and an associated IgM lambda serum immunoglobulin level of 1,730 g/dl. The tumor was treated with 5,960 rad over 47 days. On completion of radiation therapy, the tumor had regressed only minimally, and the monoclonal immunoglobulin level had decreased by 63 per cent; repeat biopsy revealed that the lymphoma had been replaced by a virtually acellular mass of amyloid. It is postulated that radiation therapy accelerated the tissue conversion of lambda light chain into the beta-pleated sheet structure characteristic of amyloid fibrils.

Levitan, N.; Rubinow, A.; Bromer, R.H.; Conlon, C.L.; Doos, W.G.; Hong, W.K.

1985-10-01

177

Successful prosthetic breast reconstruction after radiation therapy.  

PubMed

Radiation has been considered a relative contraindication to prosthetic breast reconstruction. While this dogma has been challenged by recent reports, the data on radiation and immediate prosthetic reconstruction remain contradictory. We performed a controlled retrospective review of one surgeon's 7-year experience with 21 irradiated patients who underwent tissue expander/implant breast reconstruction. When compared with nonirradiated patients, irradiated patients experienced a higher rate of seroma formation, infection, delayed healing, implant exposure, and systemic complications. The rate of capsular contracture, while significantly higher in the irradiated group, was comprised mostly of mild to moderate capsules. Hematoma formation, implant rupture, and operative revision rates were similar between the 2 groups and complication rates among irradiated patients remained overall low. This study supports prosthetic reconstruction as a reasonable option for many radiation patients. Although irradiated patients remain at higher risk for complications, overall complication rates are low and rates of successful reconstruction are high. PMID:18434827

Percec, Ivona; Bucky, Louis P

2008-05-01

178

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

179

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

180

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

Microsoft Academic Search

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

Ira J Kalet; Mary M Austin-Seymour

1997-01-01

181

BGRT: Biologically guided radiation therapy - The future is fast approaching!  

Microsoft Academic Search

Rapid advances in functional and biological imaging, predictive assays, and our understanding of the molecular and cellular responses underpinning treatment outcomes herald the coming of the long-sought goal of implementing patient-specific biologically guided radiation therapy (BGRT) in the clinic. Biological imaging and predictive assays have the potential to provide patient-specific, three-dimensional information to characterize the radiation response characteristics of tumor

X. Allen Li; Robert D. Stewart

2007-01-01

182

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.

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

183

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

184

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.

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

2013-01-01

185

Radiation Therapy after Breast-Conserving Surgery Improves Survival  

Cancer.gov

Radiation therapy after breast-conserving surgery substantially reduces the risk of cancer recurring in the breast and moderately reduces the risk of death from the disease, according to updated results from a meta-analysis by the Early Breast Cancer Trialists' Collaborative Group.

186

Simulation studies of field shaping in rotational radiation therapy  

Microsoft Academic Search

This article presents simulation studies of field shaping in rotational radiation therapy by means of two categories of beam modifying devices: protectors and shapers. The protectors used are diminished copies of the organs at risk (OARs) and stay parallel to them during gantry rotation. Thus, each protector always keeps the corresponding OAR in its shadow, significantly reducing the irradiation. The

T. Ivanova; K. Bliznakova; N. Pallikarakis

2006-01-01

187

Sick sinus syndrome as a complication of mediastinal radiation therapy  

Microsoft Academic Search

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

Sinikka Pohjola-Sintonen; K. J. K. Toetterman; Markku Kupari

1990-01-01

188

Radiation therapy in the management of patients with mesothelioma  

SciTech Connect

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

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

1982-01-01

189

Development of quality assurance in radiation therapy in North America  

Microsoft Academic Search

Although diagnostic radiology developed rapidly following Roentgen's discovery, limitations on voltage delayed penetrating external radiation therapy until after World War II. Quality assurance has developed in both the USA and Canada in many different institutions. Tolerances for implementation of the prescribed tumor dose have been established. A series of quality assurance procedures for calibration, three dimensional dose distributions, the treatment

John S. Laughlin

1984-01-01

190

Optimal adaptive control of treatment planning in radiation therapy  

Microsoft Academic Search

Radiation treatment plans, such as in oncological therapy, require the determination of a nonlinear optimal control policy, which should be adapted to the given individual and to the stage of the treatment. All too often, the treatment plans formulated assume a simplified representation.The aim of this paper is to show that the full complex representation can be adopted, if suitable

G. Arcangeli; M. Benassi; L. Nieddu; C. Passi; G. Patrizi; M. T. Russo

2002-01-01

191

Radiation therapy in the treatment of malignant salivary gland tumors.  

PubMed

A retrospective analysis of 52 patients with malignant salivary gland tumors is reported. Seventeen patients received early postoperative radiation therapy and 16 (94%) were free of local or regional disease 2-14 years following initiation of therapy, although 14 were considered at high risk of developing local recurrence. Two subjects (12%) developed distant metastases and 14 (82%) were completely disease-free. Survival and disease-free status of patients treated for recurrent or inoperable disease were much worse with two of 13 disease-free at 45 and 168 months respectively. Various workers have reported recurrence rates after surgery along at 25-38% and over 50% for many histological types. On the basis of this report early postoperative radiation therapy is recommended to reduce the risk of postsurgical recurrence. Prognostic trends relating to both histological type and location of primary disease are discussed. PMID:204407

Elkon, D; Colman, M; Hendrickson, F R

1978-02-01

192

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

193

Carnosine may reduce lung injury caused by radiation therapy.  

PubMed

Ionising radiation is known one of the most effective tools in the therapy of cancer but in many thoracic cancers, the total prescribed dose of radiation that can be safely administered to the target volume is limited by the risk of complications arising in the normal lung tissue. One of the major reasons for cellular injury after radiation is the formation of reactive oxygen species (ROS). Radiation pneumonitis is an acute phase side-effect which generally subsides after a few weeks and is followed by a chronic phase characterized by inflammation and fibrosis, that can develop months or years after irradiation. Carnosine is a dipeptide composed by the amino acids beta-histidine and l-alanine. The exact biological role of carnosine is not totally understood, but several studies have demonstrated that it possesses strong and specific antioxidant properties, protects against radiation damage,and promotes wound healing. The antioxidant mechanism of carnosine is attributed to its chelating effect against metal ions, superoxide dismutase (SOD)-like activity, ROS and free radicals scavenging ability . Either its antioxidant or anti-inflammatuar properties, we propose that carnosine ameliorates irradiation-induced lung injury. Thus, supplementing cancer patients to whom applied radiation therapy with carnosine, may provide an alleviation of the symptoms due to radiation-induced lung injury. This issue warrants further studies. PMID:16406688

Guney, Yildiz; Turkcu, Ummuhani Ozel; Hicsonmez, Ayse; Andrieu, Meltem Nalca; Guney, H Zafer; Bilgihan, Ayse; Kurtman, Cengiz

2006-01-01

194

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

195

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.

Stubbe, Christine E.; Valero, Meighan

2013-01-01

196

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

197

Renal remodeling after abdominal radiation therapy: parenchymal and functional changes.  

PubMed

OBJECTIVE. The purpose of this study was to quantify changes in renal length, volume, and function over time after upper abdominal radiation therapy. MATERIALS AND METHODS. Imaging and clinical data were retrospectively reviewed for 27 adults with abdominal radiation therapy between 2001 and 2012. All had two kidneys, radiation exposure to one kidney, and survival of at least 1 year after therapy. Mean prescribed dose was 52 ± 9 Gy to extrarenal targets. Length and volume of exposed and unexposed kidneys were measured on CT scans before treatment (baseline) and at intervals 0-3, 3-6, 6-12, 12-24, 24-36, and more than 36 months after completion of radiotherapy. Serum creatinine was correlated at each interval. Mixed-models ANOVA was used to test renal length and volume, serum creatinine, and time against multiple models to assess for temporal effects; specific time intervals were compared in pairwise manner. RESULTS. Mean follow-up duration was 35 months (range, 5-94 months). Exposed kidney length and volume progressively decreased from baseline throughout follow-up, with mean loss of 23% (p < 0.001) and 47% (p < 0.001), respectively. Slight increase in unexposed kidney length was not significant. Mean serum creatinine increased from 0.86 ± 0.18 mg/dL at baseline to 1.12 ± 0.27 mg/dL at 12-24 months (p < 0.001), then stabilized. CONCLUSION. Kidneys exposed to radiation during therapy of adjacent malignancies exhibited continuous progressive atrophy for the entire follow-up period, nearly 8 years. Volume changes were twice as great as length changes. Renal function also declined. To accurately interpret follow-up studies in cancer survivors, radiologists should be aware of the potential for progressive renal atrophy, even many years after radiation therapy. PMID:25055293

Tran, Linda K; Maturen, Katherine E; Feng, Mary U; Wizauer, Eric J; Watcharotone, Kuanwong; Parker, Robert A; Ellis, James H

2014-08-01

198

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

PubMed Central

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

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

2013-01-01

199

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.

200

Managing Radiation Therapy Side Effects: What to Do When You Feel Weak or Tired (Fatigue)  

MedlinePLUS

... National Institutes of Health Managing Radiation Therapy Side Effects What To Do When You Feel Weak or ... medicine that could help? Managing Radiation Therapy Side Effects:What To Do When You Feel Weak or ...

201

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

MedlinePLUS

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

202

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

MedlinePLUS

... talk with your doctor. Questions from men getting radiation therapy to the pelvic area: Will I still ... method should be used. Questions from men getting radiation therapy Is it okay to have sex? This ...

203

Fiber-optic Cerenkov radiation sensor for proton therapy dosimetry.  

PubMed

In proton therapy dosimetry, a fiber-optic radiation sensor incorporating a scintillator must undergo complicated correction processes due to the quenching effect of the scintillator. To overcome the drawbacks of the fiber-optic radiation sensor, we proposed an innovative method using the Cerenkov radiation generated in plastic optical fibers. In this study, we fabricated a fiber-optic Cerenkov radiation sensor without an organic scintillator to measure Cerenkov radiation induced by therapeutic proton beams. Bragg peaks and spread-out Bragg peaks of proton beams were measured using the fiber-optic Cerenkov radiation sensor and the results were compared with those of an ionization chamber and a fiber-optic radiation sensor incorporating an organic scintillator. From the results, we could obtain the Bragg peak and the spread-out Bragg peak of proton beams without quenching effects induced by the scintillator, and these results were in good agreement with those of the ionization chamber. We also measured the Cerenkov radiation generated from the fiber-optic Cerenkov radiation sensor as a function of the dose rate of the proton beam. PMID:22714456

Jang, Kyoung Won; Yoo, Wook Jae; Shin, Sang Hun; Shin, Dongho; Lee, Bongsoo

2012-06-18

204

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.

205

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

SciTech Connect

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

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

2010-12-01

206

New scoring system identifies kidney outcome with radiation therapy in acute renal allograft rejection  

Microsoft Academic Search

Purpose: To evaluate the role of radiation therapy for acute refractory renal rejection after failure of medical intervention, and to identify risk factors that influence graft survival following radiation therapy.Methods: Between June 1989 and December 1995, 53 renal transplant recipients (34 men and 19 women) were treated with localized radiation therapy for acute renal allograft rejection. Graft rejection was defined

Luci M Chen; Juan Godinez; Ronald A Thisted; E. Steve Woodle; J. Richard Thistlewaite; Claire Powers; Daniel Haraf

2000-01-01

207

Stereotactic radiation therapy for progressive residual pilocytic astrocytomas.  

PubMed

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

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

2012-08-01

208

Radiation therapy of seminoma of the testis.  

PubMed

This study is a review of 66 patients with a diagnosis of testicular seminoma, treated at the Department of Radiation Oncology, University of Louisville, from 1959 to 1978. Sixty-four of the patients were diagnosed as pure seminomas and two as spermatocytic type. The age of the patients ranged from 16 to 75 years with a median of 39. Fifty-four patients (82%) presented with swelling or mass in the testis, 7 patients with pain, 1 patient with hydrocele, and 4 patients had seminoma diagnosed incidentally. The distribution was equal for both right and left sides. There were 39 (59%) and 27 (41%) patients in stages I and II, respectively. All stage I patients received only infradiaphragmatic irradiation by a "hockey stick" field, and the majority of them received a dose of 3,200-3,600 rads in 3-4 weeks time. Stage II patients received elective irradiation to the mediastinum and neck region, in addition to the infradiaphragmatic irradiation. The 5-year actuarial survival rates for stage I and II seminomas are 96% and 92%, respectively. There were no serious complications during follow-up. The role of elective irradiation in stage I disease is discussed with a brief review of the literature. PMID:3968883

Jose, B; Perkins, P L; Kays, H; Chu, A M; Sharma, S C

1985-01-01

209

Symptomatic and asymptomatic carotid artery plaque  

PubMed Central

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

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

2011-01-01

210

Probiotic Therapy in Radiation-Induced Intestinal Injury and Repair  

PubMed Central

Intestinal injury from ionizing radiation is a clinically important entity, as enteritis symptoms occur commonly after radiotherapy for pelvic malignancies. Preventative or therapeutic options for radiation enteritis are mostly unsatisfactory; however, available data suggests that probiotic bacteria—those which confer health benefit—may have therapeutic value. Previous reports from both human trials and animal models have evaluated various end points for probiotic usage in limiting radiation-associated intestinal damage. Newer data suggests that particular probiotics and/or their secreted or derived bacterial products may have unique radioprotective properties. We will review the area with a focus on new developments surrounding probiotic therapy in radiation-induced intestinal injury and repair.

Ciorba, Matthew A.; Stenson, William F.

2014-01-01

211

[3D-CRT and intensity modulated radiation therapy (IMRT)].  

PubMed

Three-dimensional conformal radiation therapy (3D-CRT) conforms a high dose region closer to the target volume than does 2D radiation therapy. IMRT is the advanced form of 3D-CRT. With IMRT technique, using multiple intensity modulated beams, one can deliver a high dose of radiation to the target and a low dose to the surrounding normal structures. IMRT planning provides improved tumor target coverage when compared to 3D-CRT treatment planning. There is significant sparing of critical structures and other normal tissues. IMRT also produces dose distributions capable of delivering different dose prescriptions to multiple targets, providing a new opportunity for differential dose painting to increase the dose selectively to specific image-defined regions. Preliminary findings indicate that IMRT is a new clinically feasible tool in radiation oncology. The initial results of clinical studies demonstrate reduced xerostomia in head and neck cancer and also effectively reduced acute and late occurring toxicities, improving the QOL of patients treated for prostate cancer. According to these studies, IMRT will allow dose escalation, leading to better tumor control without normal tissue damage. On the other hand, there are some problems for IMRT in Japan: There are few medical physicists, which results in radiation technologists playing most clinical technological roles, including some dosimetrical and physical activities. Social recognition and economical and legal support for medical physicists should be established in providing better patient care services. PMID:14712764

Hatano, Kazuo; Narita, Yuichiro; Araki, Hiroshi; Sakai, Mitsuhiro

2003-12-01

212

Radiation therapy in the treatment of metastatic renal cell carcinoma  

SciTech Connect

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

Onufrey, V.; Mohiuddin, M.

1985-11-01

213

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.

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

2014-01-01

214

Soy Isoflavones in Conjunction With Radiation Therapy in Patients With Prostate Cancer  

Microsoft Academic Search

Soy isoflavones sensitize prostate cancer cells to radiation therapy by inhibiting cell survival pathways activated by radiation. At the same time, soy isoflavones have significant antioxidant and anti-inflammatory activity, which may help prevent the side effects of radiation. Therefore, we hypothesized that soy isoflavones could be useful when given in conjunction with curative radiation therapy in patients with localized prostate

Iftekhar U. Ahmad; Jeffrey D. Forman; Fazlul H. Sarkar; Gilda G. Hillman; Elisabeth Heath; Ulka Vaishampayan; Michael L. Cher; Fundagul Andic; Peter J. Rossi; Omer Kucuk

2010-01-01

215

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

216

Massive osteolysis of the right clavicle developing after radiation therapy  

SciTech Connect

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

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

1988-07-15

217

Adjuvant radiation therapy following mastectomy for breast cancer  

Microsoft Academic Search

Many randomized clinical trials have been performed to address the effectiveness of postmastectomy radiation therapy (PMRT)\\u000a to regional lymph nodes with or without chest wall irradiation. Although these studies have confirmed the usefulness of RT\\u000a to reduce loco-regional recurrence, the benefit of postoperative RT for survival remains controversial. Recent prospective\\u000a trials of PMRT in combination with systemic chemotherapy clearly demonstrated

Masahiro Hiraoka; Michihide Mitsumori; Keiko Shibuya

2002-01-01

218

Wound healing after radiation therapy: Review of the literature  

PubMed Central

Radiation therapy is an established modality in the treatment of head and neck cancer patients. Compromised wound healing in irradiated tissues is a common and challenging clinical problem. The pathophysiology and underlying cellular mechanisms including the complex interaction of cytokines and growth factors are still not understood completely. In this review, the current state of research regarding the pathomechanisms of compromised wound healing in irradiated tissues is presented. Current and possible future treatment strategies are critically reviewed.

2012-01-01

219

Sick sinus syndrome as a complication of mediastinal radiation therapy  

SciTech Connect

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

Pohjola-Sintonen, S.; Toetterman, K.J.K.; Kupari, M. (Helsinki Univ. Central Hospital (Finland))

1990-06-01

220

Optimized Spinal Cord Contour Propagation for Fractionated Radiation Therapy Planning  

Microsoft Academic Search

An optimized contour propagation method for head-and-neck cases in fractionated radiation therapy is presented and three-dimensional\\u000a displacements of the spinal cord are evaluated. Thirty-two planning CTs were acquired with either a Siemens Primatom or Toshiba\\u000a Aquilion CT scanner. Each case comprises several control CTs acquired in treatment position by a Siemens Primatom CT-on-rails\\u000a system. All manually segmented contours of the

A. Stoll; K. Giske; E. M. Stoiber; R. Bendl

221

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

SciTech Connect

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

Dorn, R.V. III (Mountain States Tumor Institute, Boise, ID (United States) Idaho National Engineering Lab., Idaho Falls, ID (United States))

1994-03-30

222

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

PubMed

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

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

2014-06-01

223

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

224

Cardiovascular computed tomographic assessment of the effect of combination lipoprotein therapy on coronary arterial plaque: rationale and design of the AFRICA (Atorvastatin plus Fenofibric acid in the Reduction of Intermediate Coronary Atherosclerosis) study.  

PubMed

Whether combination lipoprotein therapy targeting apolipoprotein B (apoB)- and apoA-containing lipoprotein particles and triglycerides (TGs) in low-risk, asymptomatic subjects with coronary atherosclerosis alters the natural progression of plaques is unknown. This study was designed to compare the progression of coronary atherosclerosis in asymptomatic, low-risk subjects without previously known coronary artery disease but with the presence of plaque on a combination of atorvastatin 40 mg plus fenofibric acid 135 mg daily for 18 months, using cardiovascular computed tomography (CCT). This is an investigator-initiated, single-center, prospective, double-blind, randomized, placebo-controlled, parallel-arm study. Asymptomatic subjects at low risk of cardiovascular events defined as <10% 10-year risk based on the Framingham Risk Score will be recruited, if they do not qualify for lipoprotein-lowering therapy based on the National Cholesterol Education Panel Adult Treatment Panel III guidelines. Subjects will qualify based on lipid parameters if their low-density lipoprotein cholesterol is >/=100 mg/dL and <190 mg/dL, TGs are >150 mg/dL, and the TGs/high-density lipoprotein cholesterol ratio is >3.5. Patients must have nonobstructive plaque based on CCT. Randomization will be 1:1 to either a combination of atorvastatin 40 mg plus fenofibric acid 135 mg daily or placebo for 18 months. Patients will undergo CCT at baseline and at the end of the treatment period. The primary end point will be the between-group difference in percent atheroma volume. Ultimately, this study can guide physicians about the use of a statin-fibric acid derivative combination in asymptomatic, low-risk persons with atherosclerosis. PMID:20413364

Voros, Szilard; Joshi, Parag H; Vazquez, Gustavo; Roth, Gina; Murrieta, Laura; Rinehart, Sarah; Qian, Zhen; Miller, Joseph

2010-01-01

225

Radiation dosimetry predicts IQ after conformal radiation therapy in pediatric patients with localized ependymoma  

Microsoft Academic Search

Purpose: To assess the effects of radiation dose-volume distribution on the trajectory of IQ development after conformal radiation therapy (CRT) in pediatric patients with ependymoma. Methods and Materials: The study included 88 patients (median age, 2.8 years {+-} 4.5 years) with localized ependymoma who received CRT (54-59.4 Gy) that used a 1-cm margin on the postoperative tumor bed. Patients were

Thomas E.. Merchant; Erin N. Kiehna; Li Chenghong; Xiong Xiaoping; Raymond K. Mulhern

2005-01-01

226

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.

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

2012-01-01

227

Aesthetic results following partial mastectomy and radiation therapy  

SciTech Connect

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

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

1990-05-01

228

Water equivalent plastic scintillation detectors in radiation therapy.  

PubMed

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

Beddar, A S

2006-01-01

229

Stereotactic body radiation therapy (SBRT) for genitourinary malignancies.  

PubMed

Stereotactic body radiation therapy (SBRT) is a novel treatment modality in radiation oncology that delivers a very high dose of radiation to the tumor target with high precision using single or a small number of fractions. SBRT is the result of technological advances in patient/tumor immobilization, image guidance, and treatment planning and delivery. This modality is safe and effective in both early stage primary cancer and oligometastases. Compared to the use of stereotactic radiosurgery for other tumor sites, SBRT is slow to be adopted in the management of genitourinary malignancies. There are now emerging data that show the safety and efficacy of this treatment modality in genitourinary (GU) malignancies especially in prostate cancer and renal cell carcinoma. Preclinical data, clinical experience, and challenges are reviewed and discussed. PMID:20875347

Teh, Bin S; Ishiyama, Hiromichi; Mathews, Thomas; Xu, Bo; Butler, E Brian; Mayr, Nina A; Lo, Simon S; Lu, Jiade J; Blanco, Angel I; Paulino, Arnold C; Timmerman, Robert D

2010-09-01

230

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.

Johnson, Matthew E.; Buyyounouski, Mark K.

2012-01-01

231

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

232

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

Microsoft Academic Search

In radiation therapy with high-energy photon beams (E>10MeV) 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

Alireza Naseri; Asghar Mesbahi

2010-01-01

233

Deciding on radiation therapy for prostate cancer: the physician's perspective.  

PubMed

Multiple treatment options are available for the radiation therapy of prostate cancer including whole pelvic radiotherapy (WPRT), prostate-only radiotherapy (PORT), three-dimensional conformal radiotherapy (3DCRT), intensity modulated radiotherapy (IMRT), as well as proton or neutron beam based therapies and brachytherapy. Numerous technical variations hamper objective assessment of these different treatment modalities. These variations are extensive and often subtle (dose to the prostate, the dose per fraction, number and size of fields, the photon energy, patient positioning, prostatic motion, the use of immobilization devices, 2D or 3D planning for treatment, and others) may cause interpretive uncertainty. Despite this confusion, there is some consensus. Prostate-specific antigen (PSA) nadirs, as well as pretreatment PSA levels, significantly alter outcome. Low-risk patients do well no matter which treatment they receive, although the question of dose-escalation therapy to improve results remains unanswered. High-risk patients do poorly regardless of treatment, although the addition of androgen ablation and dose-escalation therapy may improve results. Quality of life (QOL) studies continue to show a problem for radical prostatectomy (RP) patients secondary to impotence and incontinence and a problem for radiotherapy patients due to gastrointestinal (GI) disturbances. Patients can have access to any specific study through technologies such as the Internet. Although this information can be useful, the subtleties of each different article are usually beyond the understanding of most patients. This report examines some of the new radiotherapy modalities as well as corrects some misconceptions regarding radiotherapy results and morbidity. In addition, we discuss some studies comparing surgery and radiotherapy and attempt to objectively compare different radiation therapy strategies for localized prostate cancer. PMID:10975494

Krisch, E B; Koprowski, C D

2000-08-01

234

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

235

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

PubMed Central

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

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

2009-01-01

236

Detection of High-Risk Atherosclerotic Plaque  

PubMed Central

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

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

2013-01-01

237

Combination antiangiogenic therapy and radiation in head and neck cancers.  

PubMed

Tumor angiogenesis is a hallmark of advanced cancers and promotes invasion and metastasis. Over 90% of head and neck squamous cell carcinomas (HNSCC) express angiogenic factors such as vascular endothelial growth factor (VEGF). Several preclinical studies support the prognostic implications of angiogenic markers for HNSCC and currently this is an attractive treatment target in solid tumors. Since radiotherapy is one of the most commonly used treatments for HNSCC, it is imperative to identify the interactions between antiangiogenic therapy and radiotherapy, and to develop combination therapy to improve clinical outcome. The mechanisms between antiangiogenic agents and ionizing radiation are complicated and involve many interactions between the vasculature, tumor stroma and tumor cells. The proliferation and metastasis of tumor cells rely on angiogenesis/blood vessel formation. Rapid growing tumors will cause hypoxia, which up-regulates tumor cell survival factors, such as hypoxia-inducing factor-1? (HIF-1?) and vascular endothelial growth factor (VEGF), giving rise to more tumor proliferation, angiogenesis and increased radioresistance. Thus, agents that target tumor vasculature and new tumor vessel formation can modulate the tumor microenvironment to improve tumor blood flow and oxygenation, leading to enhanced radiosensitivity. In this review, we discuss the mechanisms of how antiangiogenic therapies improve tumor response to radiation and data that support this combination strategy as a promising method for the treatment of HNSCC in the future. PMID:24269532

Hsu, Heng-Wei; Wall, Nathan R; Hsueh, Chung-Tsen; Kim, Seungwon; Ferris, Robert L; Chen, Chien-Shing; Mirshahidi, Saied

2014-01-01

238

Management of arterial occlusive disease following radiation therapy.  

PubMed

Clinically significant arterial occlusive disease developed in 26 patients at between 5 months and 44 years (mean(s.d.) 10.7(12.0) years) following radiation therapy. Therapeutic radiation was associated with lesions of the carotid artery (nine patients), subclavian-axillary arteries (seven) and the abdominal aorta and its branches (10). Clinical presentations included transient ischemic attack, stroke, vertebrobasilar insufficiency, carotid bruit, upper- or lower-extremity ischemia and renovascular hypertension. Surgery for cerebrovascular insufficiency included carotid endarterectomy with vein patch, interposition grafting or subclavian-to-carotid bypass. Carotid or subclavian-to-axillary bypass was performed for upper-extremity ischemia. A combination of endarterectomy and Dacron or saphenous vein grafts was used for infrarenal reconstruction. Tunnels were placed orthotopically. Musculocutaneous flaps assisted in healing selected wounds. Ureteral catheters were useful adjuncts in abdominal vascular reconstructions. There were no operative deaths, strokes or amputations. One patient had recurrent transient ischemic attacks following subclavian-to-carotid bypass. The mean(s.d.) postoperative follow-up was 48.1(39.6) months. Patients presenting with end-organ ischemia following radiation therapy can be managed successfully with aggressive surgical revascularization using a broad spectrum of reconstructive techniques. PMID:8861426

Andros, G; Schneider, P A; Harris, R W; Dulawa, L B; Oblath, R W; Salles-Cunha, S X

1996-04-01

239

Peripheral Doses from Noncoplanar IMRT for Pediatric Radiation Therapy  

SciTech Connect

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

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

2010-01-01

240

Progress and controversies: radiation therapy for invasive breast cancer.  

PubMed

Radiation therapy is a critical component of the multidisciplinary management of invasive breast cancer. In appropriately selected patients, radiation not only improves local control, sparing patients the morbidity and distress of local recurrence, but it also improves survival by preventing seeding and reseeding of distant metastases from persistent reservoirs of locoregional disease. In recent years, considerable progress has been made toward improving our ability to select patients most likely to benefit from radiotherapy and to administer treatment in ways that maximize clinical benefit while minimizing toxicity and burden. This article reviews the role of radiation therapy in invasive breast cancer management, both after breast-conserving surgery and after mastectomy. It focuses particularly on emerging evidence that helps to define the clinical situations in which radiotherapy is indicated, the appropriate targets of treatment, and optimal approaches for minimizing both the toxicity and the burden of treatment, all in the context of the evolving surgical and systemic management of this common disease. It includes a discussion of new approaches in breast cancer radiotherapy, including hypofractionation and intensity modulation, as well as a discussion of promising avenues for future research. PMID:24357525

Jagsi, Reshma

2014-01-01

241

[Pure motor neuropathy after radiation therapy: 6 cases].  

PubMed

We report clinical and neurophysiological characteristics of six patients (five women and one man) presenting a pure motor bilateral asymmetric proximal and distal weakness in the setting of radiation therapy for Hodgkin's lymphoma in four cases, carcinoma of the uterus in one, and cancer of the ovary in one. Motor deficit, amyotrophy, cramps, fasciculations and tendinous areflexia were confined to the lower limbs in five patients and to the upper limbs in one. No sensory or sphincter disturbance was noted. The progression of the disease was slow with sometimes secondary stabilization. In some patients, CSF showed a slight increase in protein content with no cell. Blood and MRI medullary examination were normal. Delay between radiation therapy and onset of neurological symptoms range from 6 to 24 years (mean 15). Neurophysiological findings suggest ventral roots proximal conduction blocks. We found an increase F-waves latency, a complete distal palsy contrasting with persistent muscle action potential after distal stimulation, in most of the patients; and an evidence of a conduction block between the erb point and the cervical roots using magnetic stimulation in the patient with upper limbs involvement. Mechanisms and sites of nerve radiation injury remains still unclear. These data could indicate, as it was already reported, a proximal damage involving predominantly the motor roots. PMID:9773024

Lalu, T; Mercier, B; Birouk, N; Maisonobe, T; Catala, M; Le Forestier, N; Léger, J M; Bouche, P

1998-01-01

242

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

PubMed Central

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

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

2012-01-01

243

Radiation Therapy and You: A Guide to Self-Help During Cancer Treatment. (Revised October 1998).  

National Technical Information Service (NTIS)

This booklet is for patients who are receiving radiation therapy for cancer. It describes what to expect during therapy and offers suggestions for self-care during and after treatment. It explains the two most common types of radiation therapy, external r...

1998-01-01

244

Informatics in radiology: DICOM-RT-based electronic patient record information system for radiation therapy.  

PubMed

Comprehensive clinical imaging data and additional relevant information are crucial for the planning and delivery of radiation therapy in patients with cancer. Multiple stand-alone systems that make use of technologic advances in imaging, treatment planning, and treatment delivery acquire or generate key data during the course of radiation therapy. However, the data are scattered in various systems throughout the radiation therapy department, thereby compromising efficient clinical work flow. In 1997 and 1999, the Digital Imaging and Communications in Medicine (DICOM) standard was extended from radiology to radiation therapy with the ratification of seven DICOM-RT objects. These objects helped set the standard for (a) data integration and interoperability between radiation therapy equipment and information systems from different manufacturers, and (b) the use of DICOM diagnostic images in radiation therapy. More recently, key radiation therapy imaging and informatics data have been integrated to form an open-architecture comprehensive radiation therapy electronic patient record (ePR) system. The benefits of such a DICOM-RT-based ePR system are threefold: it can be used as a foundation for performing effective and efficient clinical services, as a common platform for radiation therapy data exchange and expert consultation, and for medical imaging informatics research in developing innovative decision support tools and a knowledge base for improved treatment with radiation therapy. PMID:19448106

Law, Maria Y Y; Liu, Brent; Chan, Lawrence W

2009-01-01

245

Radiation therapy in prostate cancer: a risk-adapted strategy  

PubMed Central

External-beam radiotherapy and brachytherapy, widely utilized as curative treatment modalities for prostate cancer, have undergone significant clinical and technological advances in recent decades. Contemporary radiotherapy treatment algorithms use pretreatment prognostic factors to stratify patients into low-, intermediate-, and high-risk groups that correlate with both pathologic stage of disease and risk of recurrence after treatment. The use of risk groups and additional prognostic factors guide selection of the optimal treatment modalities for individual patients. Here, the roles of external-beam radiotherapy, brachytherapy, and neoadjuvant or adjuvant androgen deprivation therapy are discussed in that context. Additional prognostic factors for recurrence in the post-prostatectomy setting and the role of adjuvant and salvage radiation therapy are also reviewed. The risk-adaptive approach in radiotherapy for prostate cancer aims to optimize cancer control outcomes while minimizing the morbidity of treatment.

Hayden, A.J.; Catton, C.; Pickles, T.

2010-01-01

246

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

247

Radiation therapy induces the DNA damage response in peripheral blood  

PubMed Central

Stereotactic body radiation therapy (SBRT) is a radiotherapy modality that delivers highly conformal, ablative doses to a well-defined target. Here, using a semiquantitative multiplexed assay to analyze ATM and H2AX phosphorylation, we show that ATM kinase activity in peripheral blood mononuclear cells is induced following SBRT. This observation of a systemic ATM kinase-dependent DNA damage response in the peripheral blood is unprecedented and promotes the use of ATM serine-1981 phosphorylation as a predictive biomarker for DNA damaging modalities and ATM inhibitors.

Bakkenist, Christopher J.; Czambel, R. Kenneth; Clump, David A.; Greenberger, Joel S.; Beumer, Jan H.; Schmitz, John C.

2013-01-01

248

3D measurement of absolute radiation dose in grid therapy  

NASA Astrophysics Data System (ADS)

Spatially fractionated radiotherapy through a grid is a concept which has a long history and was routinely used in orthovoltage radiation therapy in the middle of last century to minimize damage to the skin and subcutaneous tissue. With the advent of megavoltage radiotherapy and its skin sparing effects the use of grids in radiotherapy declined in the 1970s. However there has recently been a revival of the technique for use in palliative treatments with a single fraction of 10 to 20 Gy. In this work the absolute 3D dose distribution in a grid irradiation is measured for photons using a combination of film and gel dosimetry.

Trapp, J. V.; Warrington, A. P.; Partridge, M.; Philps, A.; Leach, M. O.; Webb, S.

2004-01-01

249

Plaque Inhibiting Oligosaccharide.  

National Technical Information Service (NTIS)

The present invention relates to a purified oligosaccharide which can be isolated from a natural source, e.g. from the cell wall polysaccharide of Streptococcus sanguis. S. sanguis is found in significant numbers in human dental plaque. This oligosacchari...

F. J. Cassels J. London

1989-01-01

250

Reversible neurotoxicity following hyperfractionated radiation therapy of brain stem glioma  

SciTech Connect

Two patients with brain stem gliomas were treated with hyperfractionated radiation therapy (HFR) (7,020 and 7,560 cGy, respectively). Despite initial clinical improvement during irradiation, both patients demonstrated clinical deterioration approximately 3 weeks after completion of radiotherapy. Cranial magnetic resonance imaging (MRI) revealed a progressive increase in distribution of abnormal brain stem signal consistent with either tumor or edema. {sup 18}FDG positron emission tomography (PET) was obtained in one patient and demonstrated a hypermetabolic lesion at diagnosis and a hypometabolic lesion at the time of clinical deterioration postirradiation. Management with a tapering dose of dexamethasone alone resulted in marked clinical (both patients) and radiographic (one patient) improvement, allowing reduction or discontinuation of this medication. These results suggest that patients with brain stem tumors demonstrating clinical and radiographic evidence of progressive tumor shortly after completion of HFR should be initially managed conservatively with dexamethasone, since these findings may be manifestations of reversible radiation-related neurotoxicity.

Griebel, M.; Friedman, H.S.; Halperin, E.C.; Wiener, M.D.; Marks, L.; Oakes, W.J.; Hoffman, J.M.; DeLong, G.R.; Schold, S.C.; Hockenberger, B. (Duke Univ. Medical Center, Durham, NC (USA))

1991-01-01

251

Sintered plaque characteristics  

NASA Technical Reports Server (NTRS)

The structural transformations occurring during sintering, the fabrication of a slurry produced sintered plaque, are detailed. Degradation of the positive electrode in performance in cycling in a nickel hydrogen battery were traced to the quality of the sintered plaque. Electrode degradation was found to be a limiting factor in the battery cycle life. Details of microstructural characterization and distribution of pores, examination of plastic flow during shrinkage, and observations of the rounding of nickel powder particles during the slurry process are presented.

Vaidyanathan, H.

1982-01-01

252

Hematopoietic bone marrow recovery after radiation therapy: MRI evaluation  

SciTech Connect

Magnetic resonance imaging (MRI) is able to detect the increase of adipocytes in the hematopoietic bone marrow that occurs as a consequence of radiotherapy and is indicative of the loss of myeloid tissue. By monitoring this process, it is also possible to determine the recovery of the bone marrow. The amount of viable hematopoietic tissue plays a fundamental role in determining whether the patient is able to undergo further antineoplastic therapy, particularly chemotherapy. We examined 35 patients who had been treated with radiotherapy for Hodgkin's lymphoma (12), uterine cervix carcinoma (nine), ovarian dysgerminoma (six), testicular seminoma (four), and non-Hodgkin's lymphoma (four). We observed that radiation-induced modifications of the MRI pattern in the bone marrow are tightly linked to two parameters; the administered radiation dose and the length of time passed after the treatment. Bone marrow recovery was observed only when patients were treated with doses lower than 50 Gy. The earlier radiation-induced modifications of the bone marrow MRI pattern occurred 6 to 12 months after irradiation, and they were most evident 5 to 6 years after the treatment. From 2 to 9 years after radiotherapy, we observed partial recovery. Complete recovery, when it occurred, was observed only 10 to 23 years after the treatment. Our results indicate that MRI studies are likely to be useful in the assessment of radiation-induced injuries.

Casamassima, F.; Ruggiero, C.; Caramella, D.; Tinacci, E.; Villari, N.; Ruggiero, M. (Univ. of Firenze (Italy))

1989-05-01

253

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.

254

Treatment of cholangiocarcinoma with oncolytic herpes simplex virus combined with external beam radiation therapy.  

PubMed

Replication-competent oncolytic herpes simplex viruses (HSV), modified by deletion of certain viral growth genes, can selectively target malignant cells. The viral growth gene gamma(1)34.5 has significant homology to GADD34 (growth arrest and DNA damage protein 34), which promotes cell cycle arrest and DNA repair in response to stressors such as radiation (XRT). By upregulating GADD34, XRT may result in greater oncolytic activity of HSV strains deficient in the gamma(1)34.5 gene. The human cholangiocarcinoma cell lines KMBC, SK-ChA-1 and YoMi were treated with NV1023, an oncolytic HSV lacking one copy of gamma(1)34.5. Viral proliferation assays were performed at a multiplicity of infection (MOI, number of viral particles per tumor cell) equal to 1, either alone or after XRT at 250 or 500 cGy. Viral replication was assessed by plaque assay. In vitro cytotoxicity assays were performed using virus at MOIs of 0.01 and 0.1, with or without XRT at 250 cGy and cell survival determined with lactate dehydrogenase assay. Established flank tumors in athymic mice were treated with a single intratumoral injection of virus (10(3) or 10(4) plaque forming units), either alone or after a single dose of XRT at 500 cGy, and tumor volumes measured. RT-PCR was used to measure GADD34 mRNA levels in all cell lines after a single dose of XRT at 250 or 500 cGy. NV1023 was tumoricidal in all three cell lines, but sensitivity to the virus varied. XRT enhanced viral replication in vitro in all cell lines. Combination treatment with low-dose XRT and virus was highly tumoricidal, both in vitro and in vivo. The greatest tumor volume reduction with combination therapy was seen with YoMi cells, the only cell line with increased GADD34 expression after XRT and the only cell line in which a synergistic treatment effect was suggested. In KMBC and SK-ChA-1 cells, neither of which showed increased GADD34 expression after XRT, tumor volume reduction was less pronounced and there was no suggestion of a synergistic effect in either case. Oncolytic HSV are effective in treating human cholangiocarcinoma cell lines, although sensitivity to virus varies. XRT-enhanced viral replication occurs through a mechanism that is not necessarily dependent on GADD34 upregulation. However, XRT-induced upregulation of GADD34 further promotes tumoricidal activity in viral strains deficient in the gamma(1)34.5 gene, resulting in treatment synergy; this effect is cell type dependent. Combined XRT and oncolytic viral therapy is a potentially important treatment strategy that may enhance the therapeutic ratios of both individual therapies. PMID:16138120

Jarnagin, W R; Zager, J S; Hezel, M; Stanziale, S F; Adusumilli, P S; Gonen, M; Ebright, M I; Culliford, A; Gusani, N J; Fong, Y

2006-03-01

255

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.

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

2011-01-01

256

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

257

Sexual function after surgical and radiation therapy for cervical carcinoma  

SciTech Connect

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

Seibel, M. (Beth Israel Hospital, Boston, MA); Freeman, M.G.; Graves, W.L.

1982-10-01

258

Outcome and Prognostic Factors of Radiation Therapy for Medulloblastoma  

SciTech Connect

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

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

2011-11-01

259

Predicting Behavioral Problems in Craniopharyngioma Survivors after Conformal Radiation Therapy  

PubMed Central

Background Although radiation therapy is a primary treatment for craniopharyngioma, it can exacerbate existing problems related to the tumor and pre-irradiation management. Survival is often marked by neurologic deficits, panhypopituitarism, diabetes insipidus, cognitive deficiencies and behavioral and social problems. Procedure The Achenbach Child Behavior Checklist (CBCL) was used to evaluate behavioral and social problems during the first five years of follow-up in 27 patients with craniopharyngioma treated with conformal radiation therapy. Results All group averages for the CBCL scales were within the age-typical range at pre-irradiation baseline. Extent of surgical resection was implicated in baseline differences for the Internalizing, Externalizing, Behavior Problem and Social scores. Significant longitudinal changes were found in Internalizing, Externalizing, Behavior Problem and School scores that correlated with tumor and treatment related factors. Conclusions The most common variables implicated in post-irradiation behavioral and social problems were CSF shunting, presence of an Ommaya reservoir, diabetes insipidus, and low pre-irradiation growth hormone levels.

Dolson, Eugenia P.; Conklin, Heather M.; Li, Chenghong; Xiong, Xiaoping; Merchant, Thomas E.

2009-01-01

260

Arc-modulated radiation therapy based on linear models  

NASA Astrophysics Data System (ADS)

This paper reports an inverse arc-modulated radiation therapy planning technique based on linear models. It is implemented with a two-step procedure. First, fluence maps for 36 fixed-gantry beams are generated using a linear model-based intensity-modulated radiation therapy (IMRT) optimization algorithm. The 2D fluence maps are decomposed into 1D fluence profiles according to each leaf pair position. Second, a mixed integer linear model is used to construct the leaf motions of an arc delivery that reproduce the 1D fluence profile previously derived from the static gantry IMRT optimization. The multi-leaf collimator (MLC) sequence takes into account the starting and ending leaf positions in between the neighbouring apertures, such that the MLC segments of the entire treatment plan are deliverable in a continuous arc. Since both steps in the algorithm use linear models, implementation is simple and straightforward. Details of the algorithm are presented, and its conceptual correctness is verified with clinical cases representing prostate and head-and-neck treatments.

Zhu, Xiaofeng; Thongphiew, Danthai; McMahon, Ryan; Li, Taoran; Chankong, Vira; Yin, Fang-Fang; Wu, Q. Jackie

2010-07-01

261

Infliximab for the treatment of plaque psoriasis  

PubMed Central

Infliximab is a monoclonal antibody that targets tumor necrosis factor-? (TNF?). It is used in the treatment of a number of inflammatory disorders including severe plaque psoriasis. TNF? is thought to have a major role in psoriasis by promoting an inflammatory infiltrate into the skin and inducing keratinocyte proliferation and preventing keratinocyte apoptosis, which directly contributes to the characteristic plaque skin lesions. Based on four randomized, placebo-controlled, double-blind clinical trials and nine open-label uncontrolled trials of the use of infliximab in plaque psoriasis, it was found that infliximab is a highly efficacious, rapid, sustainable, and relatively safe therapy. Yet as with any biologic, caution is recommended in its use as infusion reactions, lupus-like syndromes, infections, malignancies including lymphomas, as well as other rare events have been reported.

Gall, Jennifer S; Kalb, Robert E

2008-01-01

262

Simulation studies of field shaping in rotational radiation therapy.  

PubMed

This article presents simulation studies of field shaping in rotational radiation therapy by means of two categories of beam modifying devices: protectors and shapers. The protectors used are diminished copies of the organs at risk (OARs) and stay parallel to them during gantry rotation. Thus, each protector always keeps the corresponding OAR in its shadow, significantly reducing the irradiation. The shapers are used in order to obtain a more uniform dose distribution in the planning target volume (PTV) while preserving their initial orientation during gantry rotation. Thus, the use of beam modifying devices allows modulation of the beam intensity, to better fit irradiation requirements, at every gantry position. A software tool for calculations of geometrical position and dimensions of the beam modifying devices, using information about the shape, size, and position of the protected organ or area at risk as input, was developed. This tool was integrated into the in-house-developed Monte Carlo radiation therapy simulator (MCRTS), used to simulate the particle transport through the designed system. The verification of the software tool showed good agreement between experimental and simulation data, with discrepancies of less than 3%. Dose distributions in solid-geometry and voxel-based neck models were evaluated. Furthermore, the effectiveness of the shapers to modify the dose distribution outside the protected area was studied. Results demonstrated that the use of the shapers effectively improves dose uniformity. Studies using shapers of different materials were also carried out and resulted in similar dose distributions. The results of the simulation studies with a voxel-based model showed that rotational therapy with beam modifying devices offers adequate protection of the OAR and a uniform dose distribution outside the protected region. PMID:17153407

Ivanova, T; Bliznakova, K; Pallikarakis, N

2006-11-01

263

Radiation Therapy Alone for Imaging-Defined Meningiomas  

SciTech Connect

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

Korah, Mariam P., E-mail: mariam@radonc.emory.or [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); Nowlan, Adam W. [Department of Radiation Oncology, Piedmont Hospital, Atlanta, GA (United States); Johnstone, Peter A.S. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN (United States); Crocker, Ian R. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States)

2010-01-15

264

Simulation studies of field shaping in rotational radiation therapy  

SciTech Connect

This article presents simulation studies of field shaping in rotational radiation therapy by means of two categories of beam modifying devices: protectors and shapers. The protectors used are diminished copies of the organs at risk (OARs) and stay parallel to them during gantry rotation. Thus, each protector always keeps the corresponding OAR in its shadow, significantly reducing the irradiation. The shapers are used in order to obtain a more uniform dose distribution in the planning target volume (PTV) while preserving their initial orientation during gantry rotation. Thus, the use of beam modifying devices allows modulation of the beam intensity, to better fit irradiation requirements, at every gantry position. A software tool for calculations of geometrical position and dimensions of the beam modifying devices, using information about the shape, size, and position of the protected organ or area at risk as input, was developed. This tool was integrated into the in-house-developed Monte Carlo radiation therapy simulator (MCRTS), used to simulate the particle transport through the designed system. The verification of the software tool showed good agreement between experimental and simulation data, with discrepancies of less than 3%. Dose distributions in solid-geometry and voxel-based neck models were evaluated. Furthermore, the effectiveness of the shapers to modify the dose distribution outside the protected area was studied. Results demonstrated that the use of the shapers effectively improves dose uniformity. Studies using shapers of different materials were also carried out and resulted in similar dose distributions. The results of the simulation studies with a voxel-based model showed that rotational therapy with beam modifying devices offers adequate protection of the OAR and a uniform dose distribution outside the protected region.

Ivanova, T.; Bliznakova, K.; Pallikarakis, N. [Department of Medical Physics, School of Medicine, University of Patras, 26500, Rio- Patras (Greece)

2006-11-15

265

Pudendal entrapment neuropathy: a rare complication of pelvic radiation therapy.  

PubMed

Pudendal nerve entrapment (PNE) is an uncommon cause of chronic pain. Pudendal nerve entrapment typically occurs when the pudendal nerve is fused to nearby anatomical structures or trapped between the sacrotuberous and sacrospinalis ligaments. Pudendal nerve entrapment can be caused by excessive bicycling, pregnancy, anatomic abnormalities, scarring due to surgery, or as a sequela of radiation therapy. Radiation-induced peripheral neuropathy is usually chronic, progressive, and often irreversible. Radiation-induced pudendal neuropathy is much less common than the more familiar brachial plexopathy secondary to radiation treatment for breast cancer. The prevalence of PNE, however, is increasing due to improved long-term cancer survival. Diagnosis of pudendal neuralgia is essentially clinical; no specific clinical signs or complementary tests are reliably confirmatory. A detailed pain history with correlative clinical examination is paramount for accurate diagnosis. Performance of a pudendal nerve block can serve as both a diagnostic and therapeutic tool. Utilization of various imaging studies, as well as the performance of an electrophysiological study with pudendal nerve motor latency testing, may yield valuable evidence in support of a pudendal neuralgia diagnosis. We present the case of a 59-year-old man with stage IV prostate cancer, referred to the pain clinic for chronic perineal and right sided pelvic pain. His pain began insidiously, approximately 2 months after undergoing radiation treatment and chemotherapy 3 years prior. He was ultimately diagnosed as having a right sided pudendal entrapment neuropathy. His pain was refractory to all conventional treatment modalities; therefore we decided to pursue neuromodulation via a dorsal column spinal cord stimulator implant. Below, we describe the decision making process for the diagnosis and treatment of his pudendal neuropathy. PMID:24284861

Elahi, Foad; Callahan, Daniell; Greenlee, Jeremy; Dann, Tammy L

2013-01-01

266

Radiation therapy in Hodgkin's disease - decades of steady progress.  

PubMed

The treatment of lymphoproliferative diseases has changed dramatically during the last decades. The improved therapeutic results for this disease group are included among the most important achievements of modern oncohaematology. They are due to better disease staging, use of new markers for risk assessment, patient stratification in separate risk groups, implementation of highly effective chemotherapy (CHT), progress of targeted therapies using monoclonal antibodies, proteasome inhibitors, modern radiation therapy (RT) and supportive care. The achieved progress, especially in the treatment of Hodgkin's disease (HD), is an example of the fundamental dependence of clinical practice on the scientific achievements, mainly in the field of diagnostics and in the two pure anticancer therapeutic modalities: chemo- and radiotherapy. The aim of this article was to discuss the basic variants of RT in the multimodal treatment of HD and the clinical experience accumulated during the last decades. The experience gained in the area of involved field RT (IFRT) and extended field RT (EFRT), both alone or as a part of the combined-therapy protocols, is considered in detail. The role of RT is also discussed as a part of the dose-escalated CHT combined programmes for patients recurring, progressing or partially responding to treatment, carried out mainly as IFRT, total lymphoid irradiation (TLI) or total body irradiation (TBI). Regardless of the already attained achievements of the combined treatment at the present stage of development of oncological knowledge, there is still no consensus with respect to the optimal therapy of HD in children and in adult patients. New trials addressing issues of the best modality, best RT technique, optimal dose of RT, optimal number of cycles and timing of CHT are still needed. The contemporary challenge is to optimize treatment so that it can be accomplished with the least toxicity, lowest cost, and greatest efficiency possible. PMID:20658714

Gocheva, L

2010-01-01

267

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

268

Ultrasound Thermometry for Therapy-level Radiation Dosimetry  

NASA Astrophysics Data System (ADS)

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

Taylor, Courtney

2010-03-01

269

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

270

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

PubMed Central

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

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

2014-01-01

271

Changes in Pulmonary Function after Three-Dimensional Conformal Radiation Therapy, Intensity-Modulated Radiation Therapy, or Proton Beam Therapy for Non-Small Cell Lung Cancer  

PubMed Central

Summary We investigated the effect of modern radiation techniques on pulmonary function in non-small cell lung cancer patients. We found that lung diffusing capacity for carbon monoxide (DLCO) is reduced in the majority of patients after radiation. Moreover, we found that multiple factors, including pretreatment DLCO ?50% and lung and heart dosimetric data >median were associated with larger posttreatment declines in DLCO. Purpose Definitive radiotherapy for non-small cell lung cancer (NSCLC) adversely affects pulmonary function. However, the extent of these effects after radiation delivered with modern techniques is not well known. Methods and Materials We analyzed 250 patients who had received ?60 Gy radio(chemo)therapy, for primary NSCLC in 1998-2010 and had undergone pulmonary function tests (PFTs) before and within one year after treatment. Ninety three patients were treated with 3-dimensional conformal radiotherapy, 97 with intensity-modulated radiotherapy (IMRT), and 60 with proton beam therapy (PBT). Post-radiation PFT values were evaluated amongst individual patients compared to the same patient's pre-radiation value at the following time intervals: 0 to 4 (T1), 5 to 8 (T2), and 9 to 12 (T3) months. Results Lung diffusing capacity for carbon monoxide (DLCO) is reduced in the majority of patients along the 3 time periods after radiation, whereas the forced expiratory volume in 1 second per unit of vital capacity (FEV1/VC) showed an increase and decrease after radiation in a similar percentage of patients. There were baseline differences (stage, RT dose, concurrent chemotherapy) among the radiation technology groups. On multivariate analysis, the following features were associated with larger posttreatment declines in DLCO: pretreatment DLCO, gross tumor volume (GTV), lung and heart dosimetric data, and total radiation dose. Only pretreatment DLCO was associated with larger posttreatment declines in FEV1/VC. Conclusions DLCO is reduced in the majority of the patients after radiotherapy with modern techniques. Multiple factors, including GTV, pre-radiation lung function and dosimetric parameters, are associated with the DLCO decline. Prospective studies are needed to better understand whether new radiation technology such as PBT or IMRT may decrease the pulmonary impairment through greater lung sparing.

Lopez Guerra, Jose L.; Gomez, Daniel R.; Zhuang, Yan; Levy, Lawrence B.; Eapen, George; Liu, Hongmei; Mohan, Radhe; Komaki, Ritsuko; Cox, James D.; Liao, Zhongxing

2014-01-01

272

Clinical studies on the use of radiation therapy as primary treatment of early breast cancer  

SciTech Connect

The treatment of operable breast cancer by primary radiation therapy instead of mastectomy is undergoing evaluation in the United States and Europe. Retrospective studies of patients treated by primary radiation therapy show that local control and survival rates are comparable to those obtained by mastectomy. Detailed analysis of local failure following primary radiation therapy indicates the importance of excisional biopsy of the primary tumor, moderate doses of radiation to the breast and draining lymph node areas, and the use of a boost to the primary tumor area in maximizing local control. Further, the judicious use of local excision combined with meticulous radiotherapy technique yields highly satisfactory results for the majority of treated patients. Preliminary results from prospective trials also indicate that primary radiation therapy provides both local control and survival rates equivalent to mastectomy. Primary radiation therapy is becoming an increasingly important alternative to mastectomy where surgical and radiotherapeutic expertise are available to optimize both local tumor control and the final cosmetic outcome.

Harris, J.R.; Beadle, G.F.; Hellman, S.

1984-02-01

273

Scatter correction for cone-beam CT in radiation therapy  

PubMed Central

Cone-beam CT (CBCT) is being increasingly used in modern radiation therapy for patient setup and adaptive replanning. However, due to the large volume of x-ray illumination, scatter becomes a rather serious problem and is considered as one of the fundamental limitations of CBCT image quality. Many scatter correction algorithms have been proposed in literature, while a standard practical solution still remains elusive. In radiation therapy, the same patient is scanned repetitively during a course of treatment, a natural question to ask is whether one can obtain the scatter distribution on the first day of treatment and then use the data for scatter correction in the subsequent scans on different days. To realize this scatter removal scheme, two technical pieces must be in place: (i) A strategy to obtain the scatter distribution in on-board CBCT imaging and (ii) a method to spatially match a prior scatter distribution with the on-treatment CBCT projection data for scatter subtraction. In this work, simple solutions to the two problems are provided. A partially blocked CBCT is used to extract the scatter distribution. The x-ray beam blocker has a strip pattern, such that partial volume can still be accurately reconstructed and the whole-field scatter distribution can be estimated from the detected signals in the shadow regions using interpolation?extrapolation. In the subsequent scans, the patient transformation is determined using a rigid registration of the conventional CBCT and the prior partial CBCT. From the derived patient transformation, the measured scatter is then modified to adapt the new on-treatment patient geometry for scatter correction. The proposed method is evaluated using physical experiments on a clinical CBCT system. On the Catphan©600 phantom, the errors in Hounsfield unit (HU) in the selected regions of interest are reduced from about 350 to below 50 HU; on an anthropomorphic phantom, the error is reduced from 15.7% to 5.4%. The proposed method is attractive in applications where a high CBCT image quality is critical, for example, dose calculation in adaptive radiation therapy.

Zhu, Lei; Xie, Yaoqin; Wang, Jing; Xing, Lei

2009-01-01

274

Scatter correction for cone-beam CT in radiation therapy  

SciTech Connect

Cone-beam CT (CBCT) is being increasingly used in modern radiation therapy for patient setup and adaptive replanning. However, due to the large volume of x-ray illumination, scatter becomes a rather serious problem and is considered as one of the fundamental limitations of CBCT image quality. Many scatter correction algorithms have been proposed in literature, while a standard practical solution still remains elusive. In radiation therapy, the same patient is scanned repetitively during a course of treatment, a natural question to ask is whether one can obtain the scatter distribution on the first day of treatment and then use the data for scatter correction in the subsequent scans on different days. To realize this scatter removal scheme, two technical pieces must be in place: (i) A strategy to obtain the scatter distribution in on-board CBCT imaging and (ii) a method to spatially match a prior scatter distribution with the on-treatment CBCT projection data for scatter subtraction. In this work, simple solutions to the two problems are provided. A partially blocked CBCT is used to extract the scatter distribution. The x-ray beam blocker has a strip pattern, such that partial volume can still be accurately reconstructed and the whole-field scatter distribution can be estimated from the detected signals in the shadow regions using interpolation/extrapolation. In the subsequent scans, the patient transformation is determined using a rigid registration of the conventional CBCT and the prior partial CBCT. From the derived patient transformation, the measured scatter is then modified to adapt the new on-treatment patient geometry for scatter correction. The proposed method is evaluated using physical experiments on a clinical CBCT system. On the Catphan(c)600 phantom, the errors in Hounsfield unit (HU) in the selected regions of interest are reduced from about 350 to below 50 HU; on an anthropomorphic phantom, the error is reduced from 15.7% to 5.4%. The proposed method is attractive in applications where a high CBCT image quality is critical, for example, dose calculation in adaptive radiation therapy.

Zhu Lei; Xie Yaoqin; Wang Jing; Xing Lei [Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States)

2009-06-15

275

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.

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

276

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

277

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

278

Pelvic radiation therapy for gynecologic malignancy in geriatric patients  

SciTech Connect

Thirty-one patients, aged 75 years or older, who received pelvic radiation therapy as part of primary treatment for a gynecologic malignancy, were reviewed. Ten patients (32%) failed to complete their treatment and 4 patients (13%) died of treatment-related complications. The treatment-related complications were independent of increasing age, but did correlate closely with the patients' pretreatment ECOG performance status. Ten patients with performance levels of 2 or higher had a mortality rate of 30%, while 70% failed to complete treatment. Treatment fractions of greater than 220 cGy per day also resulted in unacceptably high complication rates. Alternative treatment formats should be considered in geriatric patients with poor initial performance levels.

Grant, P.T.; Jeffrey, J.F.; Fraser, R.C.; Tompkins, M.G.; Filbee, J.F.; Wong, O.S.

1989-05-01

279

Image correlation techniques in radiation therapy treatment planning.  

PubMed

A technique to spatially correlate multi-modality or serial imaging studies of the head is described. Surface fitting of a well defined structure in different imaging studies is used to determine the optimal three dimensional transformation between the coordinate systems. The transformation is then used to map volumes of interest between studies or to reslice the studies along comparable planes. The approach is feasible in the presence of variations in slice thickness, pixel size, imaging plane, or head position, and for correlations between different modalities. Correlations have been performed between serial CT, CT/MRI, and PET/CT/MRI studies. Phantom studies and clinical cases are presented. Accuracy is typically on the order of the sum of the pixel sizes between studies. Applications in radiation therapy treatment planning are described. PMID:2785845

Chen, G T; Pelizzari, C A

1989-01-01

280

[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

281

Stereotactic body radiation therapy for thoracic cancers: recommendations for patient selection, setup and therapy.  

PubMed

Advanced technologies have facilitated the development of stereotactic body radiation therapy (SBRT) programs capable of delivering ablative radiation doses for the control of lung cancers. To date, experience with these programs has been highly favorable, as reflected in the results of careful clinical trials. The medically inoperable lung cancer patient, lacking more effective options, has served as the initial clinical base to test SBRT; the therapeutic outcomes have confirmed a significant role for this approach. For many patient groups, SBRT may become a noninvasive alternative to some thoracic surgeries, especially ones with more limited therapeutic goals such as wedge resection. Despite these results, long-term evaluation of the cases treated is required to allow greater understanding of the limitations and contributions of this new modality. The successful delivery of SBRT requires the development of a comprehensive, specialized clinical program providing advanced technology and the technical expertise of physicians, physicists and therapists specially trained in SBRT applications. To achieve successful clinical outcomes, careful patient selection and attention to therapy design and delivery are required since exacting clinical procedures are involved. This chapter will outline many details essential for establishing an effective SBRT program in clinical practice. PMID:21625165

Timmerman, Robert; Heinzerling, John; Abdulrahman, Ramzi; Choy, Hak; Meyer, John L

2011-01-01

282

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

283

Stereotactic body radiation therapy for centrally-located lung tumors  

PubMed Central

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

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

2014-01-01

284

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

285

Role of stereotactic body radiation therapy for hepatocellular carcinoma.  

PubMed

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

Sanuki, Naoko; Takeda, Atsuya; Kunieda, Etsuo

2014-03-28

286

On bolus for megavoltage photon and electron radiation therapy.  

PubMed

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. PMID:23582702

Vyas, Vedang; Palmer, Lisa; Mudge, Ray; Jiang, Runqing; Fleck, Andre; Schaly, Bryan; Osei, Ernest; Charland, Paule

2013-01-01

287

Radiation therapy alone or combined surgery and radiation therapy in squamous-cell carcinoma of the penis?  

PubMed

To assess the prognostic factors and the outcome in patients with squamous-cell carcinoma of the penis, a retrospective review of 41 consecutive patients with non-metastatic invasive carcinoma of the penis, treated between 1962 and 1994, was performed. The median age was 59 years (range: 35-76 years). According to the International Union Against Cancer (UICC) 1997 classification, there were 12 (29%) T1, 24 (59%) T2, 4 (10%) T3 and 1 TX (2%) tumours. The N-classification was distributed as follows: 29 (71%) patients with N0, 8 (20%) with N1, 3 (7%) with N2 and 1 (2%) with N3. Forty-four per cent (n=18) of the patients underwent surgery: partial penectomy with (n=4) or without (n=12) lymph node dissection, or total penectomy with (n=1) or without (n=1) lymph node dissection. 23 patients were treated with radiation therapy alone, and all but 4 of the patients who were operated upon received postoperative radiation therapy (n=14). The median follow-up period was 70 months (range 20-331 months). In a median period of 12 months (range 5-139 months), 63% (n=26) of the patients relapsed (local in 18, locoregional in 2, regional in 3 and distant in 3). Local failure (stump in the operated patients, and the tumour bed in those treated with primary radiation therapy) was observed in 4 out of 16 (25%) patients treated with partial penectomy +/-postoperative radiotherapy versus 14 out of 23 (61%) treated with primary radiotherapy (P=0.06). 15 (83%) out of 18 local failures were successfully salvaged with surgery. In all patients, 5- and 10-year survival rates were 57% (95% confidence interval (CI), 41-73%) and 38% (95% CI, 21-55%), respectively. The 5-year local and locoregional rates were 57% (95% CI, 41-73%) and 48% (95% CI, 32-64%), respectively. In patients treated with primary radiotherapy, 5- and 10-year probabilities of surviving with penis preservation were 36% (95% CI, 22-50%) and 18% (95% CI, 2-34%), respectively. In multivariate analyses, survival was significantly influenced by the N-classification, and surgery was the only independent factor predicting the locoregional control. We conclude that, in patients with squamous-cell carcinoma of the penis, local control is better in patients treated with surgery. However, there seems to be no difference in terms of survival between patients treated by surgery and those treated by primary radiotherapy +/-salvage surgery, with 39% having organ preservation. PMID:11166146

Zouhair, A; Coucke, P A; Jeanneret, W; Douglas, P; Do, H P; Jichlinski, P; Mirimanoff, R O; Ozsahin, M

2001-01-01

288

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

Microsoft Academic Search

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

Joel B. Epstein; Frances L. W. Wong

1994-01-01

289

Fundamental biophysical aspects of high-energy radiations in cancer therapy  

Microsoft Academic Search

The limitations of conventional therapy with x and $gamma$ radiations ; are reported, and high-energy particulate radiations that exhibit physical and\\/or ; biological properties more suitable for cancer therapy are discussed. ; Specifically, future prospects for radiotherapy with beams of electrons, ; neutrons, negative pions, protons, $alpha$ particles, and heavy ions are ; surveyed, and some of the results of

Orton

1974-01-01

290

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

Microsoft Academic Search

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

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

2005-01-01

291

Linac-based stereotactic body radiation therapy for treatment of glomus jugulare tumors  

Microsoft Academic Search

Background: Glomus jugulare tumors are rare, typically benign, tumors that arise from the neural crest cells that are associated with the autonomic ganglia in and around the jugular bulb. Treatment options for glomus jugulare tumors include embolization followed by resection, fractionated external beam radiation therapy (EBRT), stereotactic radiosurgery (SRS), and\\/or stereotactic body radiation therapy (SBRT). Materials and methods: 18 patients

Rodney E. Wegner; Kenneth D. Rodriguez; Dwight E. Heron; Barry E. Hirsch; Robert L. Ferris; Steven A. Burton

2010-01-01

292

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

293

Pediatric meuroblastoma: postoperative radiation therapy using less than 2000 rad  

SciTech Connect

There is considerable controversy regarding the role of radiaiton therapy in the treatment of neuroblastoma. Postoperative irradiation in the range of 2500-4000 rad is commonly used in the treatment of Evans Stage II or III disease, but there are no data in the literature to suggest the optimum dose of radiation that is necessary. Because much lower doses have been used at the University of Florida, a retrospective study was undertaken in an attempt to determine the optimum dose necessary in conjunction with surgery. From March 1964 through July 1979, 21 children with Stage II or III neuroblastoma were seen at the University of Florida. One patient died postoperatively. The remainder received postoperative irradiation with doses ranging from 900 to 4500 rad. The lower dose of radiation used did not adversely influence survival, particularly for patients less than two years of age diagnosis. In this group, no patient had a local recurrence or died of disease, even though nine of 15 available patients received doses of 900-1500 rad.

Jacobson, H.M.; Marcus, R.B. Jr; Thar, T.L.; Million, R.R.; Graham-Pole, J.R.; Talbert, J.L.

1983-04-01

294

Gadolinium dose enhancement studies in microbeam radiation therapy.  

PubMed

Microbeam radiation therapy (MRT) is an innovative technique to treat brain tumors. The synchrotron generated x-ray beam, used for the treatment, is collimated and delivered in 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) have shown the sparing effect of the healthy tissue and the ablation of tumors in several animal models. It has also been determined that MRT yields a higher therapeutic index than nonsegmented beams of the same energy. This therapeutic index could be greatly improved by loading the tumor with high atomic number (Z) contrast agents. In this work, the dose enhancement factors and the peak to valley dose ratios (PVDRs) are assessed for different gadolinium (Z = 64) concentrations in the tumor and different microbeam energies by using Monte Carlo simulations (PENELOPE 2006 code). A significant decrease in the PVDR values in the tumor, and therefore a relevant increase in the dose deposition, is found in the presence of gadolinium. The optimum energy for the dose deposition in the tumor while keeping a high PVDR in the healthy tissues, which guaranties their sparing, has been investigated. PMID:19746791

Prezado, Y; Fois, G; Le Duc, G; Bravin, A

2009-08-01

295

Stereotactic body radiation therapy: a novel treatment modality.  

PubMed

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 treatment of early-stage non-small-cell lung cancer, prostate cancer, renal-cell carcinoma, and liver cancer, and in the treatment of oligometastases in the lung, liver, and spine. A large body of evidence on the use of SBRT for the treatment of primary and metastatic tumors in various sites has accumulated over the past 10-15 years, and efficacy and safety have been demonstrated. Several prospective clinical trials of SBRT for various sites have been conducted, and several other trials are currently being planned. The results of these clinical trials will better define the role of SBRT in cancer management. This article will review the radiobiologic, technical, and clinical aspects of SBRT. PMID:19997074

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

2010-01-01

296

Academic Career Selection and Retention in Radiation Oncology: The Joint Center for Radiation Therapy Experience  

SciTech Connect

Purpose: The United States healthcare system has witnessed declining reimbursement and increasing documentation requirements for longer than 10 years. These have decreased the time available to academic faculty for teaching and mentorship. The impact of these changes on the career choices of residents is unknown. The purpose of this report was to determine whether changes have occurred during the past decade in the proportion of radiation oncology trainees from a single institution entering and staying in academic medicine. Methods and Materials: We performed a review of the resident employment experience of Harvard Joint Center for Radiation Therapy residents graduating during 13 recent consecutive years (n = 48 residents). The outcomes analyzed were the initial selection of an academic vs. nonacademic career and career changes during the first 3 years after graduation. Results: Of the 48 residents, 65% pursued an academic career immediately after graduation, and 44% remained in academics at the last follow-up, after a median of 6 years. A later graduation year was associated with a decrease in the proportion of graduates immediately entering academic medicine (odds ratio, 0.78; 95% confidence interval, 0.65-0.94). However, the retention rate at 3 years of those who did immediately enter academics increased with a later graduation year (p = 0.03). Conclusion: During a period marked by notable changes in the academic healthcare environment, the proportion of graduating Harvard Joint Center for Radiation Therapy residents pursuing academic careers has been declining; however, despite this decline, the retention rates in academia have increased.

Balboni, Tracy A. [Harvard Radiation Oncology Residency Program, Boston, MA (United States)]. E-mail: tbalboni@partners.org; Chen, M.-H. [Department of Statistics, University of Connecticut, Storrs, CT (United States); Harris, Jay R. [Department of Radiation Oncology, Brigham and Women's Hospital, Dana Farber Cancer Institute, and Harvard Medical School, Boston, MA (United States); Recht, Abram [Department of Radiation Oncology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Stevenson, Mary Ann [Department of Radiation Oncology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); D'Amico, Anthony V. [Department of Radiation Oncology, Brigham and Women's Hospital, Dana Farber Cancer Institute, and Harvard Medical School, Boston, MA (United States)

2007-05-01

297

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

298

Direct aperture optimization for online adaptive radiation therapy  

SciTech Connect

This paper is the first investigation of using direct aperture optimization (DAO) for online adaptive radiation therapy (ART). A geometrical model representing the anatomy of a typical prostate case was created. To simulate interfractional deformations, four different anatomical deformations were created by systematically deforming the original anatomy by various amounts (0.25, 0.50, 0.75, and 1.00 cm). We describe a series of techniques where the original treatment plan was adapted in order to correct for the deterioration of dose distribution quality caused by the anatomical deformations. We found that the average time needed to adapt the original plan to arrive at a clinically acceptable plan is roughly half of the time needed for a complete plan regeneration, for all four anatomical deformations. Furthermore, through modification of the DAO algorithm the optimization search space was reduced and the plan adaptation was significantly accelerated. For the first anatomical deformation (0.25 cm), the plan adaptation was six times more efficient than the complete plan regeneration. For the 0.50 and 0.75 cm deformations, the optimization efficiency was increased by a factor of roughly 3 compared to the complete plan regeneration. However, for the anatomical deformation of 1.00 cm, the reduction of the optimization search space during plan adaptation did not result in any efficiency improvement over the original (nonmodified) plan adaptation. The anatomical deformation of 1.00 cm demonstrates the limit of this approach. We propose an innovative approach to online ART in which the plan adaptation and radiation delivery are merged together and performed concurrently--adaptive radiation delivery (ARD). A fundamental advantage of ARD is the fact that radiation delivery can start almost immediately after image acquisition and evaluation. Most of the original plan adaptation is done during the radiation delivery, so the time spent adapting the original plan does not increase the overall time the patient has to spend on the treatment couch. As a consequence, the effective time allotted for plan adaptation is drastically reduced. For the 0.25, 0.5, and 0.75 cm anatomical deformations, the treatment time was increased by only 2, 4, and 6 s, respectively, as compared to no plan adaptation. For the anatomical deformation of 1.0 cm the time increase was substantially larger. The anatomical deformation of 1.0 cm represents an extreme case, which is rarely observed for the prostate, and again demonstrates the limit of this approach. ARD shows great potential for an online adaptive method with minimal extension of treatment time.

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

2007-05-15

299

Primary radiation therapy for locally advanced breast cancer  

SciTech Connect

The optimal local-regional treatment for patients with Stage III breast cancer has not been determined. To evaluate the effectiveness of radiation therapy as local treatment for such patients, the results of 192 patients (five with bilateral disease) treated with radiation therapy without mastectomy between July 1, 1968 and December 31, 1981 were reviewed. Excisional biopsy (gross tumor removal) was performed in only 54 of the 197 breasts. Patients typically received 4500 to 5000 cGy in 5 weeks to the breast and draining lymph nodes; a local boost to areas of gross disease was delivered to 157 patients. Multi-agent chemotherapy was given to 53 patients. The median follow-up was 65 months. The actuarial probability of survival for the entire group was 41% at 5 years and 23% at 10 years. The probability of relapse-free survival (RFS) was 30% at 5 years and 19% at 10 years. The addition of multi-agent chemotherapy was associated with a significantly improved 5-year RFS (40% versus 26%, P = 0.02). The 5-year survival rate was 51% for patients who received adjuvant multi-agent chemotherapy and 38% for patients who did not (P = 0.16). The actuarial rate of local-regional tumor control (not censored for distant failure) for all patients was 73% at 5 years and 68% at ten years, and the crude incidence of local-regional control was 78%. Local-regional tumor control was principally influenced by radiation dose. Patients who received 6000 cGy or greater to the primary site had a better 5-year rate of control in the breast than did patients who received less than 6000 cGy (83% versus 70%, P = 0.06). Significant complications were seen in 15 patients (8%); these included moderate or severe arm edema in six patients and brachial plexopathy in four patients. Cosmetic results at last evaluation were excellent or good in 56% of evaluable patients, fair in 25%, and poor in 19%.

Sheldon, T.; Hayes, D.F.; Cady, B.; Parker, L.; Osteen, R.; Silver, B.; Recht, A.; Come, S.; Henderson, I.C.; Harris, J.R.

1987-09-15

300

Radiation therapy for the palliation of multiple myeloma  

SciTech Connect

This study reviews the experience at the University of Arizona in an effort to define the minimum effective radiation dose for durable pain relief in the majority of patients with symptomatic multiple myeloma. The records of 101 patients with multiple myeloma irradiated for palliation at the University of Arizona between 1975 and 1990 were reviewed. Three hundred sixteen sites were treated. Ten sites were asymptomatic, including six hemibody fields with advanced disease unresponsive to chemotherapy and four local fields with impending pathological fractures. Three hundred six evaluable symptomatic sites remained. The most common symptom was bone pain. Other symptoms included neurological impairment with a palpable mass. Total tumor dose ranged from 3.0 to 60 Gy, with a mean of 25 Gy. Symptom relief was obtained in 297 of 306 evaluable symptomatic sites (97%). Complete relief of symptoms was obtained in 26% and partial relief in 71%. Symptom relief was obtained in 92% of sites receiving a total dose less than 10 Gy (n = 13) and 98% of sites receiving 10 Gy or more (n = 293). No dose-response could be demonstrated. The likelihood of symptom relief was not influenced by the location of the lesion or the use of concurrent chemotherapy. Of the 297 responding sites, 6% (n = 19) relapsed after a median symptom-free interval of 16 months. Neither the probability of relapse nor the time to relapse was related to the radiation dose. Retreatment of relapsing sites provided effective palliation in all cases. Radiation therapy is effective in palliating local symptoms in multiple myeloma. A total dose of 10 Gy should provide durable symptom relief in the majority of patients. 16 refs., 3 figs., 4 tabs.

Leigh, B.R.; Kurtts, T.A.; Mack, C.F.; Matzner, M.B.; Shimm, D.S. (Univ. of Arizona, Tucson (United States))

1993-04-02

301

A comprehensive dosimetric study of pancreatic cancer treatment using three-dimensional conformal radiation therapy (3DCRT), intensity-modulated radiation therapy (IMRT), volumetric-modulated radiation therapy (VMAT), and passive-scattering and modulated-scanning proton therapy (PT).  

PubMed

With traditional photon therapy to treat large postoperative pancreatic target volume, it often leads to poor tolerance of the therapy delivered and may contribute to interrupted treatment course. This study was performed to evaluate the potential advantage of using passive-scattering (PS) and modulated-scanning (MS) proton therapy (PT) to reduce normal tissue exposure in postoperative pancreatic cancer treatment. A total of 11 patients with postoperative pancreatic cancer who had been previously treated with PS PT in University of Pennsylvania Roberts Proton Therapy Center from 2010 to 2013 were identified. The clinical target volume (CTV) includes the pancreatic tumor bed as well as the adjacent high-risk nodal areas. Internal (iCTV) was generated from 4-dimensional (4D) computed tomography (CT), taking into account target motion from breathing cycle. Three-field and 4-field 3D conformal radiation therapy (3DCRT), 5-field intensity-modulated radiation therapy, 2-arc volumetric-modulated radiation therapy, and 2-field PS and MS PT were created on the patients' average CT. All the plans delivered 50.4Gy to the planning target volume (PTV). Overall, 98% of PTV was covered by 95% of the prescription dose and 99% of iCTV received 98% prescription dose. The results show that all the proton plans offer significant lower doses to the left kidney (mean and V18Gy), stomach (mean and V20Gy), and cord (maximum dose) compared with all the photon plans, except 3-field 3DCRT in cord maximum dose. In addition, MS PT also provides lower doses to the right kidney (mean and V18Gy), liver (mean dose), total bowel (V20Gy and mean dose), and small bowel (V15Gy absolute volume ratio) compared with all the photon plans and PS PT. The dosimetric advantage of PT points to the possibility of treating tumor bed and comprehensive nodal areas while providing a more tolerable treatment course that could be used for dose escalation and combining with radiosensitizing chemotherapy. PMID:24661778

Ding, Xuanfeng; Dionisi, Francesco; Tang, Shikui; Ingram, Mark; Hung, Chun-Yu; Prionas, Evangelos; Lichtenwalner, Phil; Butterwick, Ian; Zhai, Huifang; Yin, Lingshu; Lin, Haibo; Kassaee, Alireza; Avery, Stephen

2014-01-01

302

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.

Naseri, Alireza; Mesbahi, Asghar

2010-01-01

303

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

304

Benzydamine hydrochloride in prevention and management of pain in oral mucositis associated with radiation therapy  

SciTech Connect

Benzydamine hydrochloride rinse reduced pain associated with radiation mucositis when it was used during the course of radiation therapy. Fewer patients using benzydamine rinse required systemic analgesics. All patients using benzydamine tolerated the rinse well and continued with regular rinsing throughout the course of radiation therapy. Benzydamine hydrochloride is currently undergoing clinical trials in the United States for application for approval from the Food and Drug Administration.

Epstein, J.B.; Stevenson-Moore, P.

1986-08-01

305

A Case of Bladder Cancer after Radiation Therapy for Prostate Cancer  

PubMed Central

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

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

2014-01-01

306

Enhancement of radiosensitization by metal-based nanoparticles in cancer radiation therapy  

PubMed Central

Radiation therapy performs an important function in cancer treatment. However, resistance of tumor cells to radiation therapy still remains a serious concern, so the study of radiosensitizers has emerged as a persistent hotspot in radiation oncology. Along with the rapid advancement of nanotechnology in recent years, the potential value of nanoparticles as novel radiosensitizers has been discovered. This review summarizes the latest experimental findings both in vitro and in vivo and attempts to highlight the underlying mechanisms of response in nanoparticle radiosensitization.

Su, Xiang-Yu; Liu, Pei-Dang; Wu, Hao; Gu, Ning

2014-01-01

307

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

Code of Federal Regulations, 2010 CFR

...education in radiography, nuclear medicine technology, or radiation therapy...examination in radiography, nuclear medicine technology, or radiation therapy technology shall be utilized to...licensed Radiographer, Nuclear Medicine...

2010-10-01

308

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

SciTech Connect

The authors review recent work at Los Alamos to evaluate neutron, proton, and photonuclear cross section up to 150 MeV (to 250 MeV for protons), based on experimental data and nuclear model calculations. These data are represented in the ENDF format and can be used in computer codes to simulate radiation transport. They permit calculations of absorbed dose in the body from therapy beams, and through use of kerma coefficients allow absorbed dose to be estimated for a given neutron energy distribution. For radiation protection, these data can be used to determine shielding requirements in accelerator environments, and to calculate neutron, proton, gamma-ray, and radionuclide production. Illustrative comparisons of the evaluated cross section and kerma coefficient data with measurements are given.

Chadwick, M.B.

1998-09-10

309

Rat liver tolerance for partial resection and intraoperative radiation therapy: Regeneration is radiation dose dependent  

SciTech Connect

We studied the feasibility of delivering a large single dose of intraoperative radiation as an adjuvant to partial hepatic resection. Intraoperative radiation therapy (IORT) was delivered to the remaining liver of 84 rats after partial hepatectomy to determine the acute and chronic effects of treatment on blood chemistry values, histology, survival, hepatic regeneration, and cellular appearance of the normal liver. Transient elevations in SGOT, SGPT, and alkaline phosphatase were attributed both to hepatectomy and to liver parenchymal damage induced by IORT. Microscopic examination upon necropsy, performed at frequent intervals post-treatment revealed hepatic capsular thickening with some alteration of liver architecture mainly underneath the capsule, with localized inflammation and some areas of necrosis. Survival in all groups was 100% at 45 days. Liver weight increase proved to be dose-dependent and displayed a bisphasic pattern. This study demonstrated that IORT is a feasible adjunct to surgical resection of the liver in the rat model.

Bossola, M.; Merrick, H.W.; Eltaki, A.; Bellantone, R.; Milligan, A.J.; Doglietto, G.B.; Conran, P.; Dobelbower, R.R. Jr.; Crucitti, F. (Universita Cattolica del S. Cuore, Rome (Italy))

1990-11-01

310

Radiation-Induced Lymphocyte Apoptosis to Predict Radiation Therapy Late Toxicity in Prostate Cancer Patients  

SciTech Connect

Purpose: To examine a potential correlation between the in vitro apoptotic response of lymphocytes to radiation and the risk of developing late gastrointestinal (GI)/genitourinary (GU) toxicity from radiotherapy for prostate cancer. Methods and Materials: Prostate cancer patients formerly enrolled in a randomized study were tested for radiosensitivity by using a radiation-induced lymphocyte apoptosis assay. Apoptosis was measured using flow cytometry-based Annexin-FITC/7AAD and DiOC{sub 6}/7AAD assays in subpopulations of lymphocytes (total lymphocytes, CD4+, CD8+ and CD4-/CD8-) after exposure to an in vitro dose of 0, 2, 4, or 8 Gy. Results: Patients with late toxicity after radiotherapy showed lower lymphocyte apoptotic responses to 8 Gy than patients who had not developed late toxicity (p = 0.01). All patients with late toxicity had apoptosis levels that were at or below the group mean. The negative predictive value in both apoptosis assays ranged from 95% to 100%, with sensitivity values of 83% to 100%. Apoptosis at lower dose points and in lymphocyte subpopulations had a weaker correlation with the occurrence of late toxicity. Conclusions: Lymphocyte apoptosis after 8 Gy of radiation has the potential to predict which patients will be spared late toxicity after radiation therapy. Further research should be performed to identify the specific subset of lymphocytes that correlates with late toxicity, followed by a corresponding prospective study.

Schnarr, Kara [Department of Medicine, St. George's University, Grenada, WI (Grenada); Boreham, Douglas [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON (Canada); Sathya, Jinka [Department of Radiation Oncology, University of Manitoba, Winnipeg, MB (Canada); Julian, Jim [Department of Oncology, McMaster University, Hamilton, Ontario (Canada); Dayes, Ian S. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON (Canada); Department of Oncology, McMaster University, Hamilton, Ontario (Canada)], E-mail: Ian.Dayes@jcc.hhsc.ca

2009-08-01

311

Antibacterial effect of taurolidine (2%) on established dental plaque biofilm  

Microsoft Academic Search

Preliminary data have suggested that taurolidine may bear promising disinfectant properties for the therapy of bacterial infections.\\u000a However, at present, the potential antibacterial effect of taurolidine on the supragingival plaque biofilm is unknown. To\\u000a evaluate the antibacterial effect of taurolidine on the supragingival plaque biofilm using the vital fluorescence technique\\u000a and to compare it with the effect of NaCl and

Nicole Birgit Arweiler; Thorsten Mathias Auschill; Anton Sculean

312

A practical three-dimensional dosimetry system for radiation therapy  

PubMed Central

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™) and a commercial optical computed tomography (CT) scanning system (OCTOPUS™). PRESAGE™ 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™/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 R2 value of 0.9979 and a standard error of estimation of ~1%) relative to independent measurement. The overall performance of the PRESAGE™/OCTOPUS system was evaluated with respect to a simple known 3D dose distribution, by comparison with GAFCHROMIC® EBT film and the calculated dose from a commissioned planning system. The “measured” dose distribution in a cylindrical PRESAGE™ 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™, EBT and calculated dose distributions, showed full agreement in measurable region of PRESAGE™ dosimeter (~90% of radius). The EBT and PRESAGE™ 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™ 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

2006-01-01

313

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

Microsoft Academic Search

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

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

1988-01-01

314

Periodontal attachment loss in patients after head and neck radiation therapy  

Microsoft Academic Search

Objective. The purpose of this study was to determine the potential impact of head and neck radiation therapy on the progression of periodontal attachment loss.Study design. Ten patients who received unilateral radiation fields that included the dentition were assessed before radiation treatment and after irradiation at a mean age of 6.01 years. Complete oral, dental, and periodontal examinations were completed

Joel B Epstein; Ruth Lunn; Nhu Le; Peter Stevenson-Moore

1998-01-01

315

Proposing the lymphatic target volume for elective radiation therapy for pancreatic cancer: a pooled analysis of clinical evidence  

Microsoft Academic Search

BACKGROUND: Radiation therapy is an important cancer treatment modality in both adjuvant and definitive setting, however, the use of radiation therapy for elective treatment of regional lymph nodes is controversial for pancreatic cancer. No consensus on proper selection and delineation of subclinical lymph nodal areas in adjuvant or definitive radiation therapy has been suggested either conclusively or proposed for further

Wenjie Sun; Cheng N Leong; Zhen Zhang; Jiade J Lu

2010-01-01

316

Comparison of Weight Change in Head and Neck Cancer Patients with and without Enteral Nutrition during Radiation Therapy  

Microsoft Academic Search

LEARNING OUTCOME: To compare the weight change of head and neck cancer patients during radiation therapy with and without enteral feeding.A retrospective comparison of weight change was conducted between head and neck cancer patients receiving radiation therapy. Eighty patients’ weights were evaluated based on the number of pounds lost or gained during their course of radiation therapy. The variance was

T. Nash

1996-01-01

317

Pulmonary hilar stereotactic body radiation therapy in the rat.  

PubMed

Stereotactic Body Radiation therapy (SBRT) is an emerging modality of treatment for early stage non-small cell lung carcinoma. Concerns have arisen related to increased toxicities for medial tumors. We have developed a model of high dose, hypofractionated radiotherapy to the pulmonary hilum using the Leksell Gamma-Knife. Sprague-Dawley rats received hypofractionated SBRT to the unilateral lung hilum using a custom immobilization device on the Gamma Knife. Each animal was individually scanned, treatment planned, and treated with either two 4 mm or one 8 mm collimated shots at escalating doses of 20, 40, and 80 Gy to the 50% isodose volume, encompassing the right mainstem bronchus. All animals were carefully followed post-treatment and imaged by plain film and CT. In addition, histopathological analysis of all rats was performed at selected time points. Animals treated with 4 mm collimated shots demonstrated no appreciable changes on plain films or sequential, follow-up CT scans, or histopathologically. Animals irradiated with the 8 mm collimator were less active, gained weight at a reduced rate, and demonstrated histopathological changes in 7/34 animals six months post-irradiation. Cellular atypia and interstitial pneumonitis were found, three of the seven of the animals showed clear bronchial damage and two showed vascular damage. Significant volume and time effects were found. Utilizing a novel Gamma Knife based animal model to study SBRT toxicity, it was found that the bronchus will tolerate small volumes of very high dose radiotherapy. It was postulated that radiation of the surrounding support stroma and normal tissue are important in the etiology of bronchial or hilar damage. PMID:17877431

Tinnel, B; Mendonca, M S; Henderson, M; Cummings, O; Chin-Sinex, H; Timmerman, R; McGarry, R C

2007-10-01

318

Arc-modulated radiation therapy (AMRT): a single-arc form of intensity-modulated arc therapy  

NASA Astrophysics Data System (ADS)

Arc-modulated radiation therapy (AMRT) is a novel rotational intensity-modulated radiation therapy (IMRT) technique developed for a clinical linear accelerator that aims to deliver highly conformal radiation treatment using just one arc of gantry rotation. Compared to fixed-gantry IMRT and the multiple-arc intensity-modulated arc therapy (IMAT) techniques, AMRT promises the same treatment quality with a single-arc delivery. In this paper, we present a treatment planning scheme for AMRT, which addresses the challenges in inverse planning, leaf sequencing and dose calculation. The feasibility and performance of this AMRT treatment planning scheme have been verified with multiple clinical cases of various sites on Varian linear accelerators.

Wang, Chao; Luan, Shuang; Tang, Grace; Chen, Danny Z.; Earl, Matt A.; Yu, Cedric X.

2008-11-01

319

Investigations on dynamic intensity modulated photon fields in radiation therapy  

NASA Astrophysics Data System (ADS)

The objective of this thesis is to investigate the validity of a class of intensity modulated radiation beam delivery (IMRT) with the view towards its clinical implementation. Intensity modulated photon beam (IMB) delivery is a new radiation delivery technique in external beam radiation therapy. The technique is complex in planning, delivery and verification and frequently requires a large number of beams to achieve a desired dose distribution. Therefore, an important consideration in exploiting the advantages offered by this new technology is to study the degree of accuracy with which highly conformal dose distributions can be achieved. A methodology appropriate to dosimetry and quality assurance (QA) of dynamic fields is proposed in this thesis and the theoretical modeling was improved based on the results of this work. Dynamic fields utilizing the motion of multileaf collimators (MLCs) and backup diaphragms were used to produce 1 and 2D intensity maps arbitrary in orientation with respect to collimator axis. Dynamic wedge dose profiles produced by moving diaphragms are accurate to within +/-1% of those produced with conventional techniques. The accuracy of the omni wedge with arbitrary field orientations are found within +/-2° of calculations. A dosimetric verification technique used to monitor the dynamic beam delivery for IMRT plans is introduced. The design considerations and clinical evaluation of a QA phantom, facilitating the measurement of IMRT dose distribution and conversion of photon fluence to machine deliverable monitor units are described. Benchmark tests and clinical examples for IMRT dose verification techniques are carried out to demonstrate the accuracy of the technique. in-vitro and in-vivo dose measurements of dynamic IMB's were in good agreements with the calculation model. A theoretical error analysis on the influence of systematic and random field perturbations in highly conformal beam deliveries with emphasis on its dosimetric effects is also presented. It is shown that field inaccuracies in dynamic deliveries in the order of +/-1.0 mm could lead to dose errors of 20% or more. Based on the findings of our study, we have proposed a QA procedure unique to the delivery of dynamic beams.

Parsai, Homayon

320

Computer verification of fluence map for intensity modulated radiation therapy.  

PubMed

In a treatment planning system for intensity modulated radiation therapy (IMRT), the time sequence of multileaf collimator (MLC) settings are derived from an optimal fluence map as a postoptimization process using a software module called a "leaf sequencer." The dosimetric accuracy of the dynamic delivery depends on the functionality of the module and it is important to verify independently the correctness of the leaf sequences for each field of a patient treatment. This verification is unique to the IMRT treatment and has been done using radiographic film, electronic portal imaging device (EPID) or electronic imaging system (BIS). The measurement tests both the leaf sequencer and the dynamic multileaf collimator (MLC) delivery system, providing a reliable assurance of clinical IMRT treatment. However, this process is labor intensive and time consuming. In this paper, we propose to separate quality assurance (QA) of the leaf sequencer from the dynamic MLC delivery system. We describe a simple computer algorithm for the verification of the leaf sequences. The software reads in the leaf sequences and simulates the motion of the MLC leaves. The generated fluence map is then compared quantitatively with the reference map from the treatment planning system. A set of pre-defined QA indices is introduced to measure the "closeness" between the computed and the reference maps. The approach has been used to validate the CORVUS (NOMOS Co., Sewickley, PA) treatment plans. The results indicate that the proposed approach is robust and suitable to support the complex IMRT QA process. PMID:11011737

Xing, L; Li, J G

2000-09-01

321

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.

2012-01-01

322

Intensity-Modulated Radiation Therapy in Childhood Ependymoma  

SciTech Connect

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

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

2008-07-15

323

Acid ceramidase in prostate cancer radiation therapy resistance and relapse  

NASA Astrophysics Data System (ADS)

Prostate tumor cell escape from ionizing radiation (IR)-induced killing can lead to disease progression and relapse. Sphingolipids such as ceramide and sphingosine 1-phosphate influence signal transduction pathways that regulate stress response in cancer cells. In particular, metabolism of apoptotic ceramide constitutes an important survival adaptation. Assessments of enzyme activity, mRNA, and protein demonstrated preferential upregulation of the ceramide deacylating enzyme acid ceramidase (AC) in irradiated cancer cells. Promoter-reporter and ChIP-qPCR assays revealed AC transcription by activator protein 1 (AP-1) is sensitive to pharmacological inhibition of de novo ceramide biosynthesis, identifying a protective feedback mechanism that mitigates the effects of IR-induced ceramide. Deregulation of c-Jun, in particular, induced marked radiosensitization in vitro and in vivo, which was rescued by ectopic AC over-expression. AC over-expression in prostate cancer clonogens surviving 80 Gray fractionated irradiation was associated with increased radioresistance and proliferation, suggesting a role in radiotherapy failure and relapse. Indeed, immunohistochemical analysis of human prostate cancer tissues revealed higher levels of AC after radiotherapy failure than therapy-naive adenocarcinoma, PIN, or benign tissues. By genetically downregulating AC with small interfering RNA (siRNA), we observed radiosensitization of cells using clonogenic and cytotoxicity assays. Finally, treatment with lysosomotropic small molecule inhibitors of AC, LCL385 or LCL521, induced prostate cancer xenograft radiosensitization and long-term suppression, suggesting AC is a tractable target for adjuvant radiotherapy.

Cheng, Joseph C.

324

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

325

Radiant{trademark} Liquid Radioisotope Intravascular Radiation Therapy System  

SciTech Connect

RADIANT{trademark} is manufactured by United States Surgical Corporation, Vascular Therapies Division, (formerly Progressive Angioplasty Systems). The system comprises a liquid {beta}-radiation source, a shielded isolation/transfer device (ISAT), modified over-the-wire or rapid exchange delivery balloons, and accessory kits. The liquid {beta}-source is Rhenium-188 in the form of sodium perrhenate (NaReO{sub 4}), Rhenium-188 is primarily a {beta}-emitter with a physical half-life of 17.0 hours. The maximum energy of the {beta}-particles is 2.1 MeV. The source is produced daily in the nuclear pharmacy hot lab by eluting a Tungsten-188/Rhenium-188 generator manufactured by Oak Ridge National Laboratory (ORNL). Using anion exchange columns and Millipore filters the effluent is concentrated to approximately 100 mCi/ml, calibrated, and loaded into the (ISAT) which is subsequently transported to the cardiac catheterization laboratory. The delivery catheters are modified Champion{trademark} over-the-wire, and TNT{trademark} rapid exchange stent delivery balloons. These balloons have thickened polyethylene walls to augment puncture resistance; dual radio-opaque markers and specially configured connectors.

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

1998-01-16

326

[The stereotactic body radiation therapy: initiation and clinical program].  

PubMed

We fully describe an innovative radiotherapy technique called Stereotactic Body Radiation Therapy (SBRT), and explain how this technique is commonly used for clinical purpose at the anticancer center Léon-Bérard (Lyon, France). In this technique, a non-invasive stereotactic body frame is used to locate the tumor site with a great precision. This frame is combined with a system, which enables to track the respiratory motions (Active Breathing Control (ABC) or diaphragmatic compression (DC)) in order to reduce the treatment margins for organ motion due to breathing. Thus, the volume of normal tissues that will be irradiated is considerably reduced. The dosimetry is realized with 3 CT exams performed in treatment conditions. The 3D patient "repositioning" is done with a volume CT acquisition (kV) combined with orthogonal images (kV and MV). The SBRT requires a system to limit the organ motions. Although the ABC seems to be more fastidious for patient, it would enable to use smaller margins than with DC technique. Nevertheless, the ABC is not compatible with volume CT acquisitions, which considerably improve the patient repositioning. In conclusion, the quality of repositioning and the high level of conformation enable to deliver high equivalent doses (>100 Gy) in hypofractionated mode, without increasing the treatment toxicity. The SBRT employs the last technologic innovations in radiotherapy and is therefore considered as a new efficient tool for solid tumors treatment. PMID:16978899

Gassa, F; Biston, M-C; Malet, C; Lafay, F; Ayadi, M; Badel, J-N; Carrie, C; Ginestet, C

2006-11-01

327

Nuclear data needs for radiation protection and therapy dosimetry  

SciTech Connect

New nuclear data are required for improved neutron and proton radiotherapy treatment planning as well as future applications of high-energy particle accelerators. Modern neutron radiotherapy employs energies extending to 70 MeV, while industrial applications such as transmutation and tritium breeding may generate neutrons exceeding energies of 100 MeV. Secondary neutrons produced by advanced proton therapy facilities can have energies as high as 250 MeV. Each use requires nuclear data for transport calculations and analysis of radiation effects (dosimetry). We discuss the nuclear data needs supportive of these applications including the different information requirements. As data in this energy region are sparse and likely to remain so, advanced nuclear model calculations can provide some of the needed information. ln this context, we present new evaluated nuclear data for C, N, and O. Additional experimental information, including integral and differential data, are required to confirm these results and to bound further calculations. We indicate the required new data to be measured and the difficulties in carrying out such experiments.

Chadwick, M.B. [Lawrence Livermore National Lab., CA (United States); DeLuca, P.M. Jr. [Wisconsin Univ., Madison, WI (United States). Dept of Medical Physics; Haight, R.C. [Los Alamos National Lab., NM (United States)

1995-12-31

328

Radiation therapy for carcinoma of the nasal vestibule.  

PubMed

From 1963 to 1984, 32 patients with squamous cell carcinoma of the nasal vestibule received definitive radiation therapy. Of these, 11 patients whose superficial lesions were suitably located received radium implants, and the other 21 patients were treated with a combination of electron beam and 60Co. The implant doses ranged from 60 to 75 Gy and the external beam doses ranged from 55 to 70 Gy. In 12 patients, the submandibular and subdigastric nodes were electively treated with 60Co with doses of 45 to 50 Gy, and in 12 patients the strip of skin between the nose and the free border of the mandible was also electively irradiated. None of the 11 patients treated by interstitial implant experienced treatment failure. In the 21 patients treated by external beam, one patient had primary tumor recurrence and four patients failed in the unirradiated neck. A metastasis developed in the unrradiated tissues between the nose and the neck on the only patient who died of the disease. Necrosis of the anterior art of the upper jaw of one patient developed as a result of a hot spot. Today, when treatment is calculated with the help of a computer program and special techniques to optimize tumor dose, hot spots can be prevented. PMID:3124054

Chobe, R; McNeese, M; Weber, R; Fletcher, G H

1988-01-01

329

An antiproton simulation study using MCNPX for radiation therapy.  

PubMed

Radiation therapy using antiprotons is a potential interesting future modality. Energetic antiprotons penetrate matter with almost near identical stopping powers and radio biological effectiveness (RBE) as protons in the region well before the Bragg peak region. When the antiprotons come to rest at or near the Bragg peak, they annihilate releasing almost 2 GeV per annihilation. Most of the energy is carried away on the average by 4 to 5 energetic pi mesons. The annihilations lead to roughly a doubling of physical dose with additional increase due to RBE in the Bragg peak region. This study was undertaken in order to assess the effect of the products of antiproton annihilations on depth dose profiles through MCNPX simulations. Beams of protons and antiprotons with varying energies and field sizes were used in the simulations. In our study, for 126 MeV beam, the peak to entrance (P/E) dose ratios of 4.9 for protons and 8.9 for antiprotons were found which gave the antiproton/proton P/E dose ratio equals to 1.8. This is in excellent agreement with the previous result obtained with FLUKA simulations. PMID:21876284

Michael Handley, Stephen; Ahmad, Salahuddin

2011-01-01

330

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

331

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

332

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

PubMed Central

Abstract The authors provide a survey of how images are used in radiation therapy to improve the precision of radiation therapy plans, and delivery of radiation treatment. In contrast to diagnostic radiology, where the focus is on interpretation of the images to decide if disease is present, radiation therapy quantifies the extent of the region to be treated, and relates it to the proposed treatment using a quantitative modeling system called a radiation treatment planning (RTP) system. This necessitates several requirements of image display and manipulation in radiation therapy that are not usually important in diagnosis. The images must have uniform spatial fidelity: i.e., the pixel size must be known and consistent throughout individual images, and between spatially related sets. The exact spatial relation of images in a set must be known. Radiation oncologists draw on images to define target volumes; dosimetrists use RTP systems to superimpose quantitative models of radiation beams and radiation dose distributions on the images and on the sets of organ and target contours derived from them. While this mainly uses transverse cross-sectional images, projected images are also important, both those produced by the radiation treatment simulator and the treatment machines, and so-called “digital reconstructed radiographs,” computed from spatially related sets of cross-sectional images. These requirements are not typically met by software produced for radiologists but are addressed by RTP systems. This review briefly summarizes ongoing work on software development in this area at the University of Washington Department of Radiation Oncology.

Kalet, Ira J.; Austin-Seymour, Mary M.

1997-01-01

333

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

334

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

335

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

336

Magnetic resonance imaging of vulnerable atherosclerotic plaques: current imaging strategies and molecular imaging probes.  

PubMed

The vulnerability or destabilization of atherosclerotic plaques has been directly linked to plaque composition. Imaging modalities, such as magnetic resonance (MR) imaging, that allow for evaluation of plaque composition at a cellular and molecular level, could further improve the detection of vulnerable plaque and may allow for monitoring the efficacy of antiatherosclerotic therapies. In this review we focus on MR imaging strategies for the detection and evaluation of atherosclerotic plaques and their composition. We highlight recent advancements in the development of MR pulse sequences, computer image analysis, and the use of commercially available MR contrast agents, such as gadopentic acid (Gd-DTPA), for plaque characterization. We also discuss molecular imaging strategies that are currently being used to design specific imaging probes targeted to biochemical and cellular markers of atherosclerotic plaque vulnerability. PMID:17729343

Briley-Saebo, Karen C; Mulder, Willem J M; Mani, Venkatesh; Hyafil, Fabien; Amirbekian, Vardan; Aguinaldo, Juan Gilberto S; Fisher, Edward A; Fayad, Zahi A

2007-09-01

337

Siglec receptors and hiding plaques in Alzheimer's disease.  

PubMed

Alzheimer's disease (AD) is a progressive neurodegenerative disease. One hallmark of this disease is the continuous increase in the numbers and size of aggregating amyloid plaques. The accumulation of extracellular plaques is an immunologically interesting phenomenon since microglial cells, brain-specific macrophages, should be able to cleanse the aggregating material from the human brain. Immunotherapy targeting beta-amyloid peptides in plaques with antibodies represents a promising therapy in AD. Recent progress in pattern recognition receptors of monocytes and macrophages has revealed that the sialic acid-binding, immunoglobulin-like lectin (Siglec) family of receptors is an important recognition receptor for sialylated glycoproteins and glycolipids. Interestingly, recent studies have revealed that microglial cells contain only one type of Siglec receptors, Siglec-11, which mediates immunosuppressive signals and thus inhibits the function of other microglial pattern recognition receptors, such as TLRs, NLRs, and RAGE receptors. We will review here the recent literature which clearly indicates that aggregating amyloid plaques are masked in AD by sialylated glycoproteins and gangliosides. Sialylation and glycosylation of plaques, mimicking the cell surface glycocalyx, can activate the immunosuppressive Siglec-11 receptors, as well as hiding the neuritic plaques, allowing them to evade the immune surveillance of microglial cells. This kind of immune evasion can prevent the microglial cleansing process of aggregating amyloid plaques in AD. PMID:19390836

Salminen, Antero; Kaarniranta, Kai

2009-07-01

338

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

339

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

PubMed

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

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

2009-09-15

340

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

PubMed Central

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

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

2010-01-01

341

Combination radiation-adriamycin therapy: renoprival growth, functional and structural effects in the immature mouse  

SciTech Connect

The normal tissue effects of radiation-adriamycin combination therapy were studied in the renoprival weanling mouse in an attempt to determine whether compensatory renal growth inhibition from radiation and chemotherapy could be associated with structural or functional abnormalities. Weanling BLc/sub Fl/ mice underwent unilateral nephrectomy, then single fraction renal irradiation, LD 1/21 doses of adriamycin in 5 daily doses, or combination therapy with radiation and adriamycin. Animals were sacrificed at 3, 12, and 24 weeks. Compensatory renal growth, body growth, serum blood urea nitrogen (BUN), and renal morphology by light microscopy were evaluated. Significant compensatory renal growth inhibition from radiation-adriamycin therapy exceeded that produced by adriamycin alone and radiation alone, at all time periods (p < 0.005). Body growth inhibition from radiation-adriamycin therapy or adriamycin alone significantly exceeded that produced by radiation alone (p < 0.005). Kidney and body growth inhibition from radiation-adriamycin therapy was proportionately severe. Kidney growth inhibition proportionately exceeded body growth inhibition with radiation alone; body growth inhibition proportionately exceeded kidney growth inhibition with adriamycin alone. Comparable azotemia developed by 24 weeks in both the radiation alone (p < .005) and radiation-adriamycin animals (p < 0.005), but not in the adriamycin only animals. Morphologic alterations consisting of increased glomerular density, tubular atrophy, and stromal fibrosis occurred with greater severity in the radiation-adriamycin animals than in the radiation only animals by 24 weeks; no alterations were seen in the adriamycin only animals. Using histologic criteria 750 rad plus adriamycin produced comparable injury as seen with 1000 rad alone, thus adriamycin produced an apparent dose-modifying factor of 1.33.

Donaldson, S.S.; Moskowitz, P.S.; Canty, E.L.; Fajardo, L.F.

1980-07-01

342

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

MedlinePLUS

... Radiation Therapy Side Effects What To Do About Hair Loss (Alopecia) “My doctor told me my long hair would ... deal with when it starts to fall out. Hair loss is called “alopecia.” People lose hair only in ...

343

Assessment of Lymphedema Risk Following Lymph Node Dissection and Radiation Therapy for Primary Breast Cancer.  

National Technical Information Service (NTIS)

Lymphedema is a common, chronic, and potentially devastating complication of primary breast cancer therapy. Radiation increases patients lymphedema risk up to 36% as conventional fields irradiate vital lymphatic tissues. Fusion imaging technologies that c...

A. L. Cheville

2008-01-01

344

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

345

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

346

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

347

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

348

21 CFR 892.5900 - X-ray 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 § 892.5900 X-ray radiation therapy system. (a) Identification. An...

2012-04-01

349

21 CFR 892.5710 - Radiation therapy beam-shaping block.  

... 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

350

21 CFR 892.5770 - Powered radiation therapy patient support assembly.  

... 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

351

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

352

21 CFR 892.5900 - X-ray 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 § 892.5900 X-ray radiation therapy system. (a) Identification. An...

2011-04-01

353

21 CFR 892.5900 - X-ray 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 § 892.5900 X-ray radiation therapy system. (a) Identification. An...

2010-04-01

354

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

... 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

355

21 CFR 892.5900 - X-ray radiation therapy system.  

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5900 X-ray radiation therapy system. (a) Identification. An...

2014-04-01

356

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

357

21 CFR 892.5900 - X-ray 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 § 892.5900 X-ray radiation therapy system. (a) Identification. An...

2013-04-01

358

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

359

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

360

Hierarchical Nonlinear Mixed Effect Modeling: Defining Post-radiation Therapy Relapse in Prostate Cancer Patients.  

National Technical Information Service (NTIS)

The research accomplished and described here validates and extends a model to classify prostate cancer patients according to disease relapse following definitive radiation therapy. The original model was developed within a hierarchical nonlinear mixed eff...

A. L. Hanlon

2004-01-01

361

Comparative analysis of 60Co intensity-modulated radiation therapy.  

PubMed

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

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

2008-06-21

362

Radiation therapy planning and simulation with magnetic resonance images  

NASA Astrophysics Data System (ADS)

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

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

2008-04-01

363

Intensity Modulated Radiation Therapy With Dose Painting to Treat Rhabdomyosarcoma  

SciTech Connect

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

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

2012-11-01

364

Auto-propagation of contours for adaptive prostate radiation therapy.  

PubMed

The purpose of this work is to develop an effective technique to automatically propagate contours from planning CT to cone beam CT (CBCT) to facilitate CBCT-guided prostate adaptive radiation therapy. Different from other disease sites, such as the lungs, the contour mapping here is complicated by two factors: (i) the physical one-to-one correspondence may not exist due to the insertion or removal of some image contents within the region of interest (ROI); and (ii) reduced contrast to noise ratio of the CBCT images due to increased scatter. To overcome these issues, we investigate a strategy of excluding the regions with variable contents by a careful design of a narrow shell signifying the contour of an ROI. For rectum, for example, a narrow shell with the delineated contours as its interior surface was constructed to avoid the adverse influence of the day-to-day content change inside the rectum on the contour mapping. The corresponding contours in the CBCT were found by warping the narrow shell through the use of BSpline deformable model. Both digital phantom experiments and clinical case testing were carried out to validate the proposed ROI mapping method. It was found that the approach was able to reliably warp the constructed narrow band with an accuracy better than 1.3 mm. For all five clinical cases enrolled in this study, the method yielded satisfactory results even when there were significant rectal content changes between the planning CT and CBCT scans. The overlapped area of the auto-mapped contours over 90% to the manually drawn contours is readily achievable. The proposed approach permits us to take advantage of the regional calculation algorithm yet avoiding the nuisance of rectum/bladder filling and provide a useful tool for adaptive radiotherapy of prostate in the future. PMID:18677041

Chao, Ming; Xie, Yaoqin; Xing, Lei

2008-09-01

365

Overall survival after prostate-specific-antigen-detected recurrence following conformal radiation therapy  

Microsoft Academic Search

Purpose: To study the significance, in terms of overall and cause-specific survival, of biochemical failure after conformal external-beam radiation therapy (RT) for prostate cancer.Methods and Materials: Of the 1844 patients in the Radiation Oncology prostate cancer database, 718 were deemed eligible. Patients excluded were those with N1 or M1 disease, those treated after radical prostatectomy, those who received hormone therapy

Howard M Sandler; Rodney L Dunn; P. William McLaughlin; James A Hayman; Molly A Sullivan; Jeremy M. G Taylor

2000-01-01

366

DAI provides potential imaging biomarker to indicate brain tumor response to radiation therapy  

Cancer.gov

Diffusion abnormality index (DAI) shows promise as an imaging biomarker to measure brain tumor response to radiation therapy, according to University of Michigan research being presented at the 2013 Cancer Imaging and Radiation Therapy Symposium. The study included 20 patients who had brain metastases and were treated with whole brain radiotherapy. The University of Michigan is home to the University of Michigan Comprehensive Cancer Center.

367

USC animal study finds fasting makes brain tumors more vulnerable to radiation therapy  

Cancer.gov

A new study from USC researchers is the first to show that controlled fasting improves the effectiveness of radiation therapy in cancer treatments, extending life expectancy in mice with aggressive brain tumors. The latest study, published in PLOS One, is the first to show that periods of fasting appear to have an augmenting effect on radiation therapy in treating gliomas, the most commonly diagnosed brain tumor.

368

CT evaluation of vulnerable plaque: noninvasive fortune-telling?  

PubMed

Recently, cardiac CTA has been proposed as a promising noninvasive tool for identification of rupture-prone plaques prior to a subsequent coronary event. This task is particularly challenging but the reward is high: identification of high-risk lesions could preclude plaque thrombosis and possibly prevent acute coronary syndromes. We present a case of a borderline mixed plaque with positive remodeling in the proximal left anterior descending artery (LAD). After 6 months and despite aggressive medical therapy, the patient developed acute ST-elevation myocardial infarction caused by a thrombotic lesion in the proximal LAD. We review the literature on CT characteristics of vulnerable plaque and discuss the possible preventive interventions. PMID:21505956

Opolski, Maksymilian P; Kepka, Cezary; Witkowski, Adam

2012-10-01

369

Elective Clinical Target Volumes for Conformal Therapy in Anorectal Cancer: A Radiation Therapy Oncology Group Consensus Panel Contouring Atlas  

Microsoft Academic Search

Purpose: To develop a Radiation Therapy Oncology Group (RTOG) atlas of the elective clinical target volume (CTV) definitions to be used for planning pelvic intensity-modulated radiotherapy (IMRT) for anal and rectal cancers. Methods and Materials: The Gastrointestinal Committee of the RTOG established a task group (the nine physician co-authors) to develop this atlas. They responded to a questionnaire concerning three

Robert J. Myerson; Michael C. Garofalo; Issam El Naqa; Ross A. Abrams; Aditya Apte; Walter R. Bosch; Prajnan Das; Leonard L. Gunderson; Theodore S. Hong; J. J. John Kim; Christopher G. Willett; Lisa A. Kachnic

2009-01-01

370

Using nanoparticles to enable simultaneous radiation and photodynamic therapies for cancer treatment.  

PubMed

This paper describes research into a new approach to cancer treatment through a combination of radiation and photodynamic therapies. The assumption is that supplementing conventional radiation therapy with photodynamic therapy (PDT) will enable the use of lower doses of radiation. Under this concept, scintillation or persistent luminescence nanoparticles with attached photosensitizers such as porphyrins are used as an in vivo agent for photodynamic therapy. The nanoparticle PDT agents are delivered to the treatment site. Upon exposure to ionizing radiation such as X-rays, the nanoparticles emit scintillation or persistent luminescence, which, in turn, activates the photosensitizers; as a consequence, singlet oxygen (1O2) is produced. Studies have shown that 1O2 can be effective in killing cancer cells. This is the conventional way in which PDT can augment the effectiveness of ionizing radiation. The innovation described in this study involves the use of in vivo luminescent nanoparticles so that an external light source is not required to support PDT. Consequently, application of the therapy can be more localized and the potential of damage to healthy cells is reduced. This new modality will provide an efficient, low-cost approach to PDT while still offering the benefits of augmented radiation therapy at lower doses. PMID:16736782

Chen, Wei; Zhang, Jun

2006-04-01

371

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

Microsoft Academic Search

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

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

2005-01-01

372

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

Microsoft Academic Search

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

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

2003-01-01

373

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

SciTech Connect

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

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

1986-07-01

374

Whole-brain radiation therapy in breast cancer patients with brain metastases  

Microsoft Academic Search

Over the past 10 years, improving the outcome of breast cancer patients with brain metastases has become an important challenge. The suboptimal results of whole-brain radiation therapy (WBRT) in these patients have led to the development of irradiation modalities with new technical and biological approaches. By ensuring better sparing of critical organs such as the hippocampus, highly conformal irradiation therapy

François Campana; Jean-Yves Pierga; Lionel Védrine; Damien Ricard; Sylvestre Le Moulec; Alain Fourquet; Youlia M. Kirova; Cyrus Chargari

2010-01-01

375

Locally ablative therapies for primary radiation failures: A review and critical assessment of the efficacy  

Microsoft Academic Search

A significant number of men with prostate cancer will experience biochemical failure following treatment with primary radiation\\u000a therapy. For patients with biopsyproven recurrent cancer confined to the prostate, local salvage therapy may be a potentially\\u000a curative treatment option. Most men, however, do not undergo local salvage therapy owing to difficulties in diagnosis as well\\u000a as concerns over treatment-related complications in

William C. Huang; Courtney L. Lee; James A. Eastham

2007-01-01

376

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

377

Maintenance of Sorafenib following combined therapy of three-dimensional conformal radiation therapy\\/intensity-modulated radiation therapy and transcatheter arterial chemoembolization in patients with locally advanced hepatocellular carcinoma: a phase I\\/II study  

Microsoft Academic Search

BACKGROUND: Three-dimensional conformal radiation therapy (3DCRT)\\/intensity-modulated radiation therapy (IMRT) combined with or without transcatheter arterial chemoembolization (TACE) for locally advanced hepatocellular carcinoma (HCC) has shown favorable outcomes in local control and survival of locally advanced HCC. However, intra-hepatic spreading and metastasis are still the predominant treatment failure patterns. Sorafenib is a multikinase inhibitor with effects against tumor proliferation and angiogenesis.

Jian-Dong Zhao; Jin Liu; Zhi-Gang Ren; Ke Gu; Zhen-Hua Zhou; Wen-Tao Li; Zhen Chen; Zhi-Yong Xu; Lu-Ming Liu; Guo-Liang Jiang

2010-01-01

378

Ultrasound Thermometry for Therapy-level Radiation Dosimetry  

Microsoft Academic Search

Radiation oncology is the process of administering a specified dose of radiation to a patient currently receiving treatment for a form of cancer. In this process, it is vital to know the delivered dose for a given radiation beam to correctly treat a patient. The primary reference standard for absorbed dose is established using water calorimetry. The absorbed dose, typically

Courtney Taylor

2010-01-01

379

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

SciTech Connect

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

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

2011-02-01

380

Plaque assay for murine norovirus.  

PubMed

Murine norovirus (MNV) is the only member of the Norovirus genus that efficiently grows in tissue culture. Cell lysis and cytopathic effect (CPE) are observed during MNV-1 infection of murine dendritic cells or macrophages. This property of MNV-1 can be used to quantify the number of infectious particles in a given sample by performing a plaque assay. The plaque assay relies on the ability of MNV-1 to lyse cells and to form holes in a confluent cell monolayer, which are called plaques. Multiple techniques can be used to detect viral infections in tissue culture, harvested tissue, clinical, and environmental samples, but not all measure the number of infectious particles (e.g. qRT-PCR). One way to quantify infectious viral particles is to perform a plaque assay, which will be described in detail below. A variation on the MNV plaque assay is the fluorescent focus assay, where MNV antigen is immunostained in cell monolayers. This assay can be faster, since viral antigen expression precedes plaque formation. It is also useful for titrating viruses unable to form plaques. However, the fluorescent focus assay requires additional resources beyond those of the plaque assay, such as antibodies and a microscope to count focus-forming units. Infectious MNV can also be quantified by determining the 50% Tissue Culture Infective Dose (TCID50). This assay measures the amount of virus required to produce CPE in 50% of inoculated tissue culture cells by endpoint titration. However, its limit of detection is higher compared to a plaque assay. In this article, we describe a plaque assay protocol that can be used to effectively determine the number of infectious MNV particles present in biological or environmental samples. This method is based on the preparation of 10-fold serial dilutions of MNV-containing samples, which are used to inoculate a monolayer of permissive cells (RAW 264.7 murine macrophage cells). Virus is allowed to attach to the cell monolayer for a given period of time and then aspirated before covering cells with a mixture of agarose and cell culture media. The agar enables the spread of viral progeny to neighboring cells while limiting spread to distantly located cells. Consequently, infected cells are lysed and form holes in the monolayer known as plaques. Upon sufficient spread of virus, plaques become visible following staining of cells with dyes, like neutral red, methylene blue, or crystal violet. At low dilutions, each plaque originates from one infectious viral particle and its progeny, which spread to neighboring cells. Thus, counting the number of plaques allows one to calculate plaque-forming units (PFU) present in the undiluted sample. PMID:22951568

Gonzalez-Hernandez, Mariam B; Bragazzi Cunha, Juliana; Wobus, Christiane E

2012-01-01

381

Subarachnoid dissemination of pineal germinoma 9 years after radiation therapy without local relapse--case report.  

PubMed

A 22-year-old female developed intracranial and spinal subarachnoid metastases 9 years after radiation therapy for a pineal germinoma. Computed tomographic scans showed no evidence of local recurrence. Cerebrospinal axis irradiation achieved total remission. Delayed subarachnoid dissemination may be caused by germinoma cells remaining dormant in the subarachnoid space, outside the radiation field. PMID:1723161

Tokoro, K; Chiba, Y; Murase, S; Yagishita, S; Kyuma, Y

1991-11-01

382

Analysis of weekly complete blood counts in patients receiving standard fractionated partial body radiation therapy  

Microsoft Academic Search

Purpose: Hematopoiesis is among the most sensitive systems in the body to radiation. Routine complete blood counts (CBCs) are common in clinical radiotherapy practice. Only a few studies have attempted to characterize the behavior of peripheral blood levels during partial body radiation therapy with field sizes smaller than those used in hemibody or total nodal irradiation. Such information is needed

Farley E. Yang; Florin Vaida; Lani Ignacio; Alan Houghton; Jaishanker Nautiyal; Howard Halpern; Harold Sutton; Srinivasan Vijayakumar

1995-01-01

383

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

Microsoft Academic Search

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

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

2001-01-01

384

The long-term side effects of radiation therapy for benign brain tumors in adults  

Microsoft Academic Search

Radiation therapy plays an integral part in managing intracranial tumors. While the risk:benefit ratio is considered acceptable for treating malignant tumors, risks of long-term complications of radiotherapy need thorough assessment in adults treated for benign tumors. Many previously reported delayed complications of radiotherapy can be attributed to inappropriate treatment or to the sensitivity of a developing child's brain to radiation.

Ossama Al-Mefty; Jane E. Kersh; Anupam Routh; Robert R. Smith

1990-01-01

385

Implementation of a therapy radiation dose measurement system using a microcomputer.  

National Technical Information Service (NTIS)

In this paper, the therapy radiation dose measurement system has been implemented by using a microcomputer after radiation was irradiated on diodes from the MM22 microtron accelerator. We have displayed 7-channel diode output values on the LCD after proce...

D. H. Lee J. S. Chai Y. S. Kim S. S. Hong M. Y. Lee

1996-01-01

386

Individualized estimates of second cancer risks after contemporary radiation therapy for Hodgkin lymphoma  

Microsoft Academic Search

BACKGROUND. Estimates of radiation-related second cancer risk among Hodgkin lymphoma survivors are largely based on radiation therapy (RT) fields and doses no longer in use, and these estimates do not account for differences in normal tissue dose among individual patients. This study gives individualized estimates for the risks of lung and female breast cancer expected with contemporary involved-field RT and

David C. Hodgson; Eng-Siew Koh; Tu Huan Tran; Mostafa Heydarian; Richard Tsang; Melania Pintilie; Tony Xu; Lei Huang; Rainer K. Sachs; David J. Brenner

2007-01-01

387

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

388

Breathing interplay effects during proton radiation therapy and development of repainting solutions  

Microsoft Academic Search

The movement from passive scattering to active spot scanning in proton radiation therapy introduces the problem of interplay effects when elements of beam motion have a similar time scale to periodic tumor motion, as in a lung tumor. This can lead to significant deviations from the planned radiation dose. Although the repetition of a field over many treatment sessions tends

Daniel Robertson; Joao Seco; Alexei Trofimov; Harald Paganetti

2006-01-01

389

Inverse planning optimization method for intensity modulated radiation therapy.  

PubMed

In order to facilitate the leaf sequencing process in intensity modulated radiation therapy (IMRT), and design of a practical leaf sequencing algorithm, it is an important issue to smooth the planned fluence maps. The objective is to achieve both high-efficiency and high-precision dose delivering by considering characteristics of leaf sequencing process. The key factor which affects total number of monitor units for the leaf sequencing optimization process is the max flow value of the digraph which formulated from the fluence maps. Therefore, we believe that one strategy for compromising dose conformity and total number of monitor units in dose delivery is to balance the dose distribution function and the max flow value mentioned above. However, there are too many paths in the digraph, and we don't know the flow value of which path is the maximum. The maximum flow value among the horizontal paths was selected and used in the objective function of the fluence map optimization to formulate the model. The model is a traditional linear constrained quadratic optimization model which can be solved by interior point method easily. We believe that the smoothed maps from this model are more suitable for leaf sequencing optimization process than other smoothing models. A clinical head-neck case and a prostate case were tested and compared using our proposed model and the smoothing model which is based on the minimization of total variance. The optimization results with the same level of total number of monitor units (TNMU) show that the fluence maps obtained from our model have much better dose performance for the target/non-target region than the maps from total variance based on the smoothing model. This indicates that our model achieves better dose distribution when the algorithm suppresses the TNMU at the same level. Although we have just used the max flow value of the horizontal paths in the diagraph in the objective function, a good balance has been achieved between the dose conformity and the total number of monitor units. This idea can be extended to other fluence map optimization model, and we believe it can also achieve good performance. PMID:23617286

Lan, Yihua; Ren, Haozheng; Li, Cunhua; Min, Zhifang; Wan, Jinxin; Ma, Jianxin; Hung, Chih-Cheng

2013-10-01

390

Prostate Stereotactic Ablative Radiation Therapy Using Volumetric Modulated Arc Therapy to Dominant Intraprostatic Lesions?  

PubMed Central

Purpose To investigate boosting dominant intraprostatic lesions (DILs) in the context of stereotactic ablative radiation therapy (SABR) and to examine the impact on tumor control probability (TCP) and normal tissue complication probability (NTCP). Methods and Materials Ten prostate datasets were selected. DILs were defined using T2-weighted, dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging. Four plans were produced for each dataset: (1) no boost to DILs; (2) boost to DILs, no seminal vesicles in prescription; (3) boost to DILs, proximal seminal vesicles (proxSV) prescribed intermediate dose; and (4) boost to DILs, proxSV prescribed higher dose. The prostate planning target volume (PTV) prescription was 42.7 Gy in 7 fractions. DILs were initially prescribed 115% of the PTVProstate prescription, and PTVDIL prescriptions were increased in 5% increments until organ-at-risk constraints were reached. TCP and NTCP calculations used the LQ-Poisson Marsden, and Lyman-Kutcher-Burman models respectively. Results When treating the prostate alone, the median PTVDIL prescription was 125% (range: 110%-140%) of the PTVProstate prescription. Median PTVDIL D50% was 55.1 Gy (range: 49.6-62.6 Gy). The same PTVDIL prescriptions and similar PTVDIL median doses were possible when including the proxSV within the prescription. TCP depended on prostate ?/? ratio and was highest with an ?/? ratio = 1.5 Gy, where the additional TCP benefit of DIL boosting was least. Rectal NTCP increased with DIL boosting and was considered unacceptably high in 5 cases, which, when replanned with an emphasis on reducing maximum dose to 0.5 cm3 of rectum (Dmax0.5cc), as well as meeting existing constraints, resulted in considerable rectal NTCP reductions. Conclusions Boosting DILs in the context of SABR is technically feasible but should be approached with caution. If this therapy is adopted, strict rectal constraints are required including Dmax0.5cc. If the ?/? ratio of prostate cancer is 1.5 Gy or less, then high TCP and low NTCP can be achieved by prescribing SABR to the whole prostate, without the need for DIL boosting.

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

2014-01-01

391

Biological-based optimization and volumetric modulated arc therapy delivery for stereotactic body radiation therapy  

SciTech Connect

Purpose: To describe biological-based optimization and Monte Carlo (MC) dose calculation-based treatment planning for volumetric modulated arc therapy (VMAT) delivery of stereotactic body radiation therapy (SBRT) in lung, liver, and prostate patients. Methods: Optimization strategies and VMAT planning parameters using a biological-based optimization MC planning system were analyzed for 24 SBRT patients. Patients received a median dose of 45 Gy [range, 34-54 Gy] for lung tumors in 1-5 fxs and a median dose of 52 Gy [range, 48-60 Gy] for liver tumors in 3-6 fxs. Prostate patients received a fractional dose of 10 Gy in 5 fxs. Biological-cost functions were used for plan optimization, and its dosimetric quality was evaluated using the conformity index (CI), the conformation number (CN), the ratio of the volume receiving 50% of the prescription dose over the planning target volume (Rx/PTV50). The quality and efficiency of the delivery were assessed according to measured quality assurance (QA) passing rates and delivery times. For each disease site, one patient was replanned using physical cost function and compared to the corresponding biological plan. Results: Median CI, CN, and Rx/PTV50 for all 24 patients were 1.13 (1.02-1.28), 0.79 (0.70-0.88), and 5.3 (3.1-10.8), respectively. The median delivery rate for all patients was 410 MU/min with a maximum possible rate of 480 MU/min (85%). Median QA passing rate was 96.7%, and it did not significantly vary with the tumor site. Conclusions: VMAT delivery of SBRT plans optimized using biological-motivated cost-functions result in highly conformal dose distributions. Plans offer shorter treatment-time benefits and provide efficient dose delivery without compromising the plan conformity for tumors in the prostate, lung, and liver, thereby improving patient comfort and clinical throughput. The short delivery times minimize the risk of patient setup and intrafraction motion errors often associated with long SBRT treatment delivery times.

Diot, Quentin; Kavanagh, Brian; Timmerman, Robert; Miften, Moyed [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States); Department of Radiation Oncology, University of Texas Southwestern Medical School, Dallas, Texas 75390 (United States); Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States)

2012-01-15

392

Accelerated partial breast irradiation using external beam conformal radiation therapy: a review.  

PubMed

Lumpectomy followed by whole breast radiation therapy (i.e. breast conservation therapy (BCT)) is the standard of care for management of early stage breast cancer. However, its utilization has not been maximized because of a number of reasons including the logistic issues associated with the 5-6 weeks of radiation treatment. Also, pathological and clinical data suggest that most ipsilateral breast cancer recurrences are in the vicinity of the lumpectomy. Accelerated partial breast irradiation (APBI) is an approach that treats only the lumpectomy bed plus a 1-2 cm margin, rather than the whole breast with higher doses of radiation in a shorter period of time. There has been growing interest for APBI and various approaches have been developed and are under phase I-III clinical studies. This paper reviews external beam conformal radiation therapy (EBCRT) as a possible technique to APBI. The various EBCRT approaches such as 3D conformal radiation therapy, IMRT, proton therapy, tomotherapy, and volumetric arc therapy are discussed. Issues with the implementation of these techniques such as target volume delineation and organ motion are also presented. It is evident that EBCRT has potential for APBI of a selected group of early breast cancer patient. However, issues with setup errors and breathing motions need to be adequately addressed. PMID:21376625

Njeh, Christopher F; Saunders, Mark W; Langton, Christian M

2012-01-01

393

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

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

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

396

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

397

Imaging of the unstable plaque  

Microsoft Academic Search

Atherosclerosis is now considered a systemic inflammatory disorder affecting the arterial tree. Inflammation plays a role in all stages of the disease, from the initiation of the fatty streak to the final stage of plaque rupture. Atherosclerotic plaques that demonstrate the features of active inflammation are more likely to become symptomatic. In addition to having a higher risk of developing

Kiat Tsong Tan; Gregory Y. H. Lip

2008-01-01

398

Routes to chemical plaque control  

Microsoft Academic Search

A logical approach to the prevention of periodontal disease is through excellent supragingival plaque control. Such control is not generally achieved by mechanical oral hygiene procedures alone. Thus, there is a clear rationale for the use of antiplaque agents to augment mechanical means. The principle routes to chemical plaque control are to prevent colonization of the tooth surface, to inhibit

D. Cummins

1991-01-01

399

Denitrification in human dental plaque  

Microsoft Academic Search

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

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

2010-01-01

400

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

401

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

402

The clinical development of molecularly targeted agents in combination with radiation therapy: a pharmaceutical perspective.  

PubMed

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. PMID:22819210

Ataman, Ozlem U; Sambrook, Sally J; Wilks, Chris; Lloyd, Andrew; Taylor, Amanda E; Wedge, Stephen R

2012-11-15

403

Plaque Assay for Rickettsia rickettsii  

PubMed Central

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

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

1969-01-01