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1

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

SciTech Connect

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

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

2011-07-01

2

Radiation therapy  

MedlinePLUS

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

3

Radiation Therapy  

MedlinePLUS

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

4

Choroidal melanoma: I-125 plaque therapy  

SciTech Connect

An iodine-125 eye plaque was used to treat 58 patients with choroidal melanoma. Patients were followed up for a mean of 48.7 months. Fifty patients had medium-sized lesions (height between 3.1 and 8.0 mm and base diameter less than 16.0 mm), and six patients had large lesions. There were 24 lesions less than 3.0 mm from the optic nerve. The average radiation dose to the apex of the tumor was 8,468 cGy (dose rate, 71 cGy per hour). Initial local disease control was achieved in 50 patients (86.2%). One patient with local treatment failure received another plaque treatment, which controlled disease, so the total disease control rate was 87.9%. Only eight patients died of their disease. Complications were similar to those with other treatment methods, but none of the patients in this study developed optic nerve atrophy.

Bosworth, J.L.; Packer, S.; Rotman, M.; Ho, T.; Finger, P.T.

1988-10-01

5

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, ...

6

Radiation Therapy  

MedlinePLUS

... benign (not cancerous) or malignant (cancerous). Radiation therapy kills cancer cells and keeps them from growing and ... deliver the exact amount of radiation necessary to kill the cells. It usually takes only a few ...

7

Plaque Therapy and Scatter Dose Using {sup 252}Cf Sources  

SciTech Connect

As melanomas are radioresistant to conventional low-linear energy transfer (LET) radiations such as photons and electrons, {sup 252}Cf (high-LET due to neutrons) may offer more promising clinical results. Although {sup 252}Cf also emits photons and electrons, the majority of absorbed dose is imparted by the high-LET radiation. This study examines the impact of scattering material on the neutron dose distributions for {sup 252}Cf plaque therapy (used to treat surface lesions like melanoma). Neutrons were transported through a 10-cm-diam water phantom with a thickness of either 5 or 10 cm using the MCNP radiation transport code. The phantom was surrounded by vacuum; the {sup 252}Cf neutron energy spectrum was modeled as a Maxwellian distribution; and the source was a bare point positioned at 1.0, 0.5, or {epsilon} above or below the water/vacuum interface. These source positions were chosen to mimic the case where a plaque locates the source either above the skin's surface, e.g., 2{pi} scattering geometry, or if layers of tissue-equivalent bolus materials were placed atop the implant to provide radiation backscatter, 4{pi} geometry. Differences between the 2{pi} and 4{pi} geometries were maximized closest to the source and for source positions farthest from the water/vacuum interface. Therefore, the maximum radiation dose (closest to the {sup 252}Cf source) may be minimized by not including scattering material for plaque therapy. However, for nonrelativistic, elastic scattering for protons by neutrons, the proton range increases with neutron energy. This result was expected since the neutron energy spectrum degrades at increasing depth and the proportion of fast neutron dose to total dose is maximized closest to the source in the 2{pi} geometry. Future studies will examine this effect as a function of neutron energy, will consider synergy with the low-LET {sup 252}Cf dose component and include experimental measurements, and will assess this technique to possibly improve in vivo dose distributions.

Mark J. Rivard; Anita Mahajan

2000-11-12

8

Dosimetric Benefit of a New Ophthalmic Radiation Plaque  

SciTech Connect

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

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

2012-12-01

9

Gallbladder Cancer: Radiation Therapy  

MedlinePLUS

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

10

Choroidal melanoma: I-125 plaque therapy  

Microsoft Academic Search

An iodine-125 eye plaque was used to treat 58 patients with choroidal melanoma. Patients were followed up for a mean of 48.7 months. Fifty patients had medium-sized lesions (height between 3.1 and 8.0 mm and base diameter less than 16.0 mm), and six patients had large lesions. There were 24 lesions less than 3.0 mm from the optic nerve. The

J. L. Bosworth; S. Packer; M. Rotman; T. Ho; P. T. Finger

1988-01-01

11

Radiation Therapy (For Parents)  

MedlinePLUS

... have many questions and concerns about it. About Radiation Therapy In radiation therapy, high-energy radiation from ... surgery to remove tumors or cancerous areas. How Radiation Is Given Radiation therapy is administered two ways: ...

12

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

SciTech Connect

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

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

2012-09-01

13

Radiation Therapy  

MedlinePLUS

... or hospital). Then a large machine called a simulator will deliver the exact amount of radiation necessary ... receive the daily dose of radiation. While the simulator is on, you'll have to lie very ...

14

Identifying Vulnerable Plaques with Acoustic Radiation Force Impulse Imaging  

NASA Astrophysics Data System (ADS)

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

Doherty, Joshua Ryan

15

Radiation Therapy  

MedlinePLUS

... energy to the tumor, while sparing nearby normal tissue. In this way, the risk of the common side effects of radiation to the liver, such as nausea, ulcers in the stomach or intestines, are minimized. In general, smaller liver ...

16

Radiation related complications after ruthenium plaque radiotherapy of uveal melanoma  

Microsoft Academic Search

AIMS\\/BACKGROUND: To analyse radiation related complications and secondary enucleation after irradiation of malignant uveal melanoma with ruthenium-106 plaques. METHODS: A series of 100 consecutive eyes irradiated in 1981-91 was analysed using the life table method and the Cox proportional hazards model. The median apical and scleral tumour dose was 100 Gy (range 15-200 Gy) and 1000 Gy (range 200-1200 Gy),

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

1996-01-01

17

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

SciTech Connect

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

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

2005-09-01

18

Rhabdomyosarcoma: Radiation Therapy  

MedlinePLUS

... techniques, such as stereotactic radiotherapy and proton beam radiotherapy, are discussed briefly in the section “ What’s new in rhabdomyosarcoma research and treatment? ” Possible side effects The side effects of radiation therapy depend on ...

19

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

PubMed Central

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

Kasim, Sazzli; Moran, Darragh; McFadden, Eugene

2012-01-01

20

Combined iodine-125 plaque irradiation and indirect ophthalmoscope laser therapy of choroidal malignant melanomas: Comparison with iodine-125 and cobalt-60 plaque radiotherapy alone  

Microsoft Academic Search

The authors studied the short-term impact of combined episcleral iodine-125 plaque radiotherapy and argon laser treatment in a series of 24 patients with choroidal malignant melanoma. All patients underwent plaque therapy prior to their initial laser session. All laser treatments were performed with an indirect ophthalmoscope argon green laser, using low-power, long-duration exposures. The endpoint of laser therapy was a

James J. Augsburger; Markus Kleineidam; Donald Mullen

1993-01-01

21

Radiation therapy imaging apparatus  

SciTech Connect

This patent describes a radiation therapy imaging apparatus for providing images in a patient being treated on a radiation therapy apparatus for verification and monitoring of patient positioning and verification of alignment and shaping of the radiation field of the radiation therapy apparatus. It comprises: a high-energy treatment head for applying a radiation dose to a patient positioned on a treatment table, and a gantry rotatable about an isocentric axis and carrying the treatment head for permitting the radiation dose to be applied to the patient from any of a range of angles about the isocentric axis; the radiation therapy imaging apparatus including a radiation therapy image detector which comprises a video camera mounted on the gantry diametrically opposite the treat head, an elongated light-excluding enclosure enveloping the camera to exclude ambient light from the camera, a fluoroscopic plate positioned on a distal end of the enclosure remote from the camera and aligned with the head to produce a fluoroscopic image in response to radiation applied from the head through the patient, mirror means in the enclosure and oriented for reflecting the image to the camera to permit monitoring on a viewing screen of the position of the radiation field in respect to the patient, and means for retracting at least the distal end of the enclosure from a position in which the fluoroscopic plate is disposed opposite the treatment head without disturbing the position of the camera on the gantry, so that the enclosure can be collapsed and kept from projecting under the treatment table when the patient is being positioned on the treatment table.

Chou, T.J.; Shoenfeld, H.; Greenway, W.C.

1991-02-19

22

Radiation Therapy for Lung Cancer  

MedlinePLUS

... health. Radiation Therapy Radiation is a high-energy X-ray that can be used to treat lung cancer noninvasively. Radiation therapy works within cancer cells by damaging their ability to multiply. When these ...

23

Radiation Therapy for Testicular Cancer  

MedlinePLUS

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

24

Radiation Therapy: Additional Treatment Options  

MedlinePLUS

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

25

Bile Duct (Cholangiocarcinoma) Cancer: Radiation Therapy  

MedlinePLUS

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

26

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

27

Radiation therapy: orbital tumors.  

PubMed

Orbital tumors are rare overall, comprising 0.1% of all tumors and less than 20% of all orbital diseases. Tumors may be benign, locally aggressive, or malignant. Of the malignant tumors, lymphomas and metastases are the most common and are primarily seen in the elderly population. While surgery and chemotherapeutic agents are often employed in the management of these lesions, not all patients are candidates for these therapies. Radiation therapy offers a noninvasive, well-tolerated primary treatment modality, whereby vision-sparing is feasible in many cases. In this chapter, we review an array of non-neoplastic entities and orbital tumors, for which there exists a role for radiation, and the radiotherapeutic techniques and applications in their management. PMID:23989130

Marwaha, Gaurav; Macklis, Roger; Singh, Arun D

2013-01-01

28

Radiation Therapy Technology Professional Curriculum  

E-print Network

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

Berdichevsky, Victor

29

Radiation Therapy for Gynecologic Cancers  

MedlinePLUS

... Typically, radiation therapy is done with high energy X-rays, or photons, for the bulk of the treatment. Diff erent techniques can be used for treatment. Three- dimensional conformal radiotherapy (3-D CRT) combines multi- ple radiation treatment ...

30

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

31

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

PubMed

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

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

2008-03-01

32

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.

33

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

34

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

35

Radiation Therapy for Cancer  

MedlinePLUS

... including physicists and dosimetrists ) use sophisticated computers to design the details of the exact radiation plan that ... to travel. The patient’s general health and medical history. Whether the patient will have other types of ...

36

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. ...

37

Complications of intraoperative radiation therapy  

Microsoft Academic Search

The authors have studied the severe complications occurring after treatment with intraoperative radiation therapy (IORT) in patients with locally advanced carcinoma of the rectum. Four groups of patients were compared: Group 1 (80 patients) had treatment with surgery alone for mobile and resectable tumors; Group 2 (23 patients) had treatment with high dose preoperative irradiation followed by surgical resection for

Joel E. Tepper; Leonard L. Gunderson; Erica Orlow; Alfred M. Cohen; Stephen E. Hedberg; William U. Shipley; Peter H. Blitzer; Tyvin Rich

1984-01-01

38

Radiation Therapy for Skin Cancer  

MedlinePLUS

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

39

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

40

Radiation Therapy and Hearing Loss  

SciTech Connect

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

Bhandare, Niranjan [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, Florida (United States); Jackson, Andrew [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Eisbruch, Avraham; Pan, Charlie C. [Department of Radiation Oncology, University of Michigan (United States); Flickinger, John C. [Department of Radiation Oncology, University of Pittsburgh Medical Center (United States); Antonelli, Patrick [Department of Otolaryngology, University of Florida College of Medicine, Gainesville, Florida (United States); Mendenhall, William M., E-mail: mendwm@shands.ufl.ed [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, Florida (United States)

2010-03-01

41

Pulp innervation after radiation therapy  

SciTech Connect

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

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

1986-12-01

42

[Radiation therapy of eyelid carcinomas].  

PubMed

Forty patients with histologically verified tumors of the eyelid, partly being pretreated surgically, were irradiated and reexamined. The irradiations were performed with an apparatus for surface therapy using soft rays. The radiation quality was between 55 and 100 kV, the dose between 3000 and 6000 rd. The single doses amounted to 300 or 400 rd. The rate of recurrences after primary irradiation of basaliomas was 5,5%, the rate of recovery 94,5%. The patients who underwent primary operation show a distinctly increased rate of recurrences. The percentage of complications was small, amounting to 8%. Primary irradiation is recommended for the treatment of stages T1 and T2 of eyelid tumors, the percentage of recovery being high and the number of complications small. Advanced stages ought to be treated according to the site and infiltration of the tumor either by the telecaesium apparatus under conditions of semi-deep therapy with use of a lead satellite for protection of the cristalline lens and with following soft-ray therapy, or by primary operation followed by radiation therapy. PMID:1258084

Scherer, E; Schietzel, M

1976-02-01

43

Novel anti-microbial therapies for dental plaque-related diseases  

Microsoft Academic Search

Control of dental plaque-related diseases has traditionally relied on non-specific removal of plaque by mechanical means. As our knowledge of oral disease mechanisms increases, future treatment is likely to be more targeted, for example at small groups of organisms, single species or at key virulence factors they produce. The aim of this review is to consider the current status as

Robert P. Allaker; C. W. Ian Douglas

2009-01-01

44

Radiation therapy for visual pathway tumors.  

PubMed

The multimodality management of visual pathway tumors frequently involves radiation. Most commonly, photons are delivered via multiple focused beams aimed at the tumor while sparing adjacent tissues. The dose can be delivered in multiple treatments (radiation therapy) or in a single treatment (radiosurgery). Children with visual pathway gliomas should be treated with chemotherapy alone, delaying the use of radiation therapy until progression. Definitive radiation therapy of optic nerve sheath meningiomas results in stable vision in most patients. Radiation therapy or radiosurgery for pituitary tumors can result in control of both tumor growth and hormone hypersecretion. Postoperative radiation therapy or radiosurgery of craniopharyngiomas significantly improves local control rates compared with surgery alone. Radiation therapy is highly effective for eradicating orbital pseudolymphoma and lymphoma. The risk of complications from radiation treatment is dependent on the organ at risk, the cumulative dose it receives, and the dose delivered per fraction. PMID:18769290

Stieber, Volker W

2008-09-01

45

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

46

Radiation therapy for brain tumors  

SciTech Connect

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

Wara, W.M.

1985-05-01

47

A case of aseptic pleuropericarditis in a patient with chronic plaque psoriasis under methotrexate therapy  

E-print Network

with chronic plaque psoriasis under methotrexate therapypsoriasis since the age of 30, when he began oral methotrexateMethotrexate is frequently used worldwide for the treatment of cutaneous and arthropatic psoriasis.

2010-01-01

48

Insufficiency fracture after radiation therapy  

PubMed Central

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

Oh, Dongryul

2014-01-01

49

Radiation Therapy for Soft Tissue Sarcomas  

MedlinePLUS

... Clinical trials for soft tissue sarcomas Complementary and alternative therapies for soft tissue ... for soft tissue sarcomas Radiation therapy uses high-energy rays (such as x-rays) or particles to ...

50

Protection and measurement in radiation therapy.  

PubMed

In radiation therapy, unlike most other applications involving radiation, the intention is to deliver high doses of radiation to diseased tissue, constrained by the effects of radiation to healthy tissue. With regard to patient exposure, the radiation protection framework of justification, optimization, and limitation is a direct part of the prescription process of radiation therapy. Staff and public exposures are typically far below occupational maximum permissible exposures. However, a number of other issues arise in radiation therapy that fall into the category of radiation protection. After an historical review, this paper discusses several contemporary and emerging concerns within radiation therapy, including fetal dose, secondary malignancies, and dose to implantable devices, all of which involve accurate dose assessment outside the intended treatment volume. Other concerns include quality and safety, molecularly based disease assessment and treatment, and other novel treatment strategies. The paper ends with a discussion of the interplay between best practices and regulatory oversight. PMID:25551506

Sutlief, Steven G

2015-02-01

51

Radiation Therapy and You: Support for People with Cancer  

MedlinePLUS

Radiation Therapy and You: Support for People With Cancer Radiation Therapy and You is for people who ... ePub This booklet covers: Questions and Answers About Radiation Therapy. Answers common questions, such as what radiation ...

52

Radiation therapy for Graves' disease  

SciTech Connect

We used radiation therapy (a total of 2,000 rads) to treat 14 patients (three men and 11 women, ranging in age from 27 to 72 years) with Graves' disease. Three of these patients had refused to take corticosteroids and the other 11 had failed to respond to them, had experienced side effects, or had other contraindications to their use. After follow-up periods ranging from six months to three years, soft-tissue inflammation was reduced in 13 of the 14 patients. All but two patients showed a decrease in proptosis of 1 to 3 mm. Myopathy showed the least improvement. Although we noted transient eyelid erythema, there were no permanent sequelae and none of the patients has had a recurrence of the inflammation.

Brennan, M.W.; Leone, C.R. Jr.; Janaki, L.

1983-08-01

53

Advanced Semiconductor Dosimetry in Radiation Therapy  

SciTech Connect

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

Rosenfeld, Anatoly B. [Centre for Medical Radiation Physics, University of Wollongong, Wollongong NSW 2522 (Australia)

2011-05-05

54

Advanced Semiconductor Dosimetry in Radiation Therapy  

NASA Astrophysics Data System (ADS)

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

Rosenfeld, Anatoly B.

2011-05-01

55

21 CFR 892.5300 - Medical neutron radiation therapy system.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

56

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

57

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

58

21 CFR 892.5300 - Medical neutron radiation therapy system.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Medical neutron radiation therapy system. 892.5300 Section...Devices § 892.5300 Medical neutron radiation therapy system. (a) Identification. A medical neutron radiation therapy system is a device...

2012-04-01

59

21 CFR 892.5750 - Radionuclide radiation therapy system.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Radionuclide radiation therapy system. 892.5750 Section...Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification. A radionuclide radiation therapy system is a device...

2013-04-01

60

21 CFR 892.5300 - Medical neutron radiation therapy system.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Medical neutron radiation therapy system. 892.5300 Section...Devices § 892.5300 Medical neutron radiation therapy system. (a) Identification. A medical neutron radiation therapy system is a device...

2014-04-01

61

21 CFR 892.5750 - Radionuclide radiation therapy system.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Radionuclide radiation therapy system. 892.5750 Section...Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification. A radionuclide radiation therapy system is a device...

2014-04-01

62

21 CFR 892.5750 - Radionuclide radiation therapy system.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Radionuclide radiation therapy system. 892.5750 Section...Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification. A radionuclide radiation therapy system is a device...

2010-04-01

63

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

64

21 CFR 892.5750 - Radionuclide radiation therapy system.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Radionuclide radiation therapy system. 892.5750 Section...Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification. A radionuclide radiation therapy system is a device...

2011-04-01

65

21 CFR 892.5750 - Radionuclide radiation therapy system.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Radionuclide radiation therapy system. 892.5750 Section...Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification. A radionuclide radiation therapy system is a device...

2012-04-01

66

21 CFR 892.5840 - Radiation therapy simulation system.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

67

21 CFR 892.5300 - Medical neutron radiation therapy system.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

68

21 CFR 892.5300 - Medical neutron radiation therapy system.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Medical neutron radiation therapy system. 892.5300 Section...Devices § 892.5300 Medical neutron radiation therapy system. (a) Identification. A medical neutron radiation therapy system is a device...

2013-04-01

69

A catheter-based radiation detector for endovascular detection of atheromatous plaques  

Microsoft Academic Search

Purpose Although various radiopharmaceuticals have been developed for the detection of atheromas, external imaging techniques have limitations when it comes to the detection of small plaques. In this study, we developed a charged particle-sensitive detector for the endovascular detection of small plaques. Methods The device consists of a probe, an automatic pullback unit and a controller. The probe, which consists

Takahiro Mukai; Ryuji Nohara; Mikako Ogawa; Seigo Ishino; Naoshige Kambara; Kazuaki Kataoka; Toru Kanoi; Kazuhiro Saito; Hiroshi Motomura; Junji Konishi; Hideo Saji

2004-01-01

70

A Catheter-Based Intravascular Radiation Detector ofVulnerablePlaques  

Microsoft Academic Search

Detection of vulnerable plaques before rupture is important in preventing acute coronary events such as myocardial infarction. Althoughtherapeuticstrategiessuchaspercutaneoustranslumi- nal coronary angioplasty appear to prevent coronary occlusion and consequently may lead to improved prognosis in these pa- tients, a method of detecting vulnerable plaques has not been established. A nuclear method that uses an intravascular radia- tion detector (IVRD) with the

Ryohei Hosokawa; Naoshige Kambara; Muneo Ohba; Takahiro Mukai; Mikako Ogawa; Hiroshi Motomura; Noriaki Kume; Hideo Saji; Toru Kit; Ryuji Nohara

71

Radiation therapy for renal transplant rejection reactions  

SciTech Connect

Forty-four renal transplant patients were given radiation therapy for severe rejection phenomena. The 29 patients who had only one course of irradiation had a 52.3% successful function rate. Fifteen patients received from two to four courses of irradiation with an ultimate 60% rate of sustained function. Fifty patients who received only steroid and other medical management but no irradiation had a 60% rate of successful renal function. In the irradiation group, no patient whose creatinine level did not respond to radiation therapy maintained a functioning kidney. The data indicate that the overall successful function rate is maintained by radiation therapy in patients who show severe allograft rejection phenomena.

Peeples, W.J.; Wombolt, D.G.; El-Mahdi, A.M.; Turalba, C.I.

1982-01-01

72

Galactic cosmic radiation leads to cognitive impairment and increased a? plaque accumulation in a mouse model of Alzheimer's disease.  

PubMed

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 (56)Fe particle irradiation in an APP/PS1 mouse model of Alzheimer's disease (AD). We demonstrated 6 months after exposure to 10 and 100 cGy (56)Fe 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. PMID:23300905

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

2012-01-01

73

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 false X-ray therapy and other radiation therapy services: Scope. 410.35...410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including...

2010-10-01

74

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

Code of Federal Regulations, 2013 CFR

...2013-10-01 false X-ray therapy and other radiation therapy services: Scope. 410.35...410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including...

2013-10-01

75

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

Code of Federal Regulations, 2014 CFR

...2014-10-01 false X-ray therapy and other radiation therapy services: Scope. 410.35...410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including...

2014-10-01

76

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 false X-ray therapy and other radiation therapy services: Scope. 410.35...410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including...

2012-10-01

77

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

Code of Federal Regulations, 2011 CFR

...2011-10-01 false X-ray therapy and other radiation therapy services: Scope. 410.35...410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including...

2011-10-01

78

Hypofractionation in radiation therapy and its impact  

SciTech Connect

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

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

2008-01-15

79

Comparing Postoperative Radiation Therapies for Brain Metastases  

Cancer.gov

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

80

Radiation Sensitization in Cancer Therapy.  

ERIC Educational Resources Information Center

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

Greenstock, Clive L.

1981-01-01

81

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

82

Particle Radiation Therapy: Requiem or Reveille  

PubMed Central

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

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

1979-01-01

83

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

SciTech Connect

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

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

2012-02-01

84

The Accumulation of Protoporphyrin IX in Plaque Psoriasis After Topical Application of 5-Aminolevulinic Acid Indicates a Potential for Superficial Photodynamic Therapy  

Microsoft Academic Search

The success reported for the treatment of superficial skin carcinomas by photodynamic therapy with topical application of the photosensitizer precursor 5-aminolevulinic acid has therapeutic implications for the treatment of other skin disorders. This paper describes the accumulation of the photosensitizing agent protoporphyrin IX in areas of plaque psoriasis by monitoring of the fluorescence emission induced by low-intensity laser excitation at

Mark R. Stringer; Paul Collins; Dominic J. Robinson; Graeme I. Stables; Robert A. Sheehan-Dare

1996-01-01

85

Radiation therapy: posterior segment complications.  

PubMed

Therapeutic radiation to the posterior segment of the eye is a common option for posterior segment tumors. Such tumors are often malignant, but sometimes, benign neoplasms are treated with ionizing radiation. Also, non-neoplastic intraocular lesions like wet age-related macular degeneration may be treated with radiotherapy. Orbital disease, both neoplastic lesions like optic nerve sheath meningioma and non-neoplastic entities like Graves' ophthalmopathy may be treated with radiotherapy and this may include radiation of the optic nerve and posterior segment of the eye. Occasionally, radiotherapy of extraocular malignant disease, involving, e.g. the paranasal sinuses, may cause significant radiation damage to the eye. Complications after radiation to the posterior segment of the eye are largely related to the radiation dose to the posterior segment. The amount of irradiated volume of normal tissue and fractionation are also important for the development of radiation complications to the posterior segment. Radiation retinopathy is the most common complication of the posterior segment, but radiation optic neuropathy also occurs frequently. Radiation scleral necrosis is less frequent probably due to the radioresistance of the scleral collagen. These complications have the potential to cause blindness (radiation retinopathy and optic neuropathy) or enucleation of the eye (scleral necrosis). Although numerous treatments have been advocated, management of radiation-induced damage remains controversial. Efficacy for any treatment still needs to be proven and, if possible, the best option by far is to minimize radiation changes to normal tissue. PMID:23989132

Seregard, Stefan; Pelayes, David E; Singh, Arun D

2013-01-01

86

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

87

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

PubMed Central

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

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

2014-01-01

88

Resource Letter MPRT-1: Medical Physics in Radiation Therapy  

NASA Astrophysics Data System (ADS)

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

Ratliff, Steven T.

2009-09-01

89

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

90

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. PMID:24436535

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

2013-01-01

91

Radiation therapy for early stage lung cancer.  

PubMed

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. PMID:24436535

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

2013-06-01

92

Overview of image-guided radiation therapy  

SciTech Connect

Radiation therapy has gone through a series of revolutions in the last few decades and it is now possible to produce highly conformal radiation dose distribution by using techniques such as intensity-modulated radiation therapy (IMRT). The improved dose conformity and steep dose gradients have necessitated enhanced patient localization and beam targeting techniques for radiotherapy treatments. Components affecting the reproducibility of target position during and between subsequent fractions of radiation therapy include the displacement of internal organs between fractions and internal organ motion within a fraction. Image-guided radiation therapy (IGRT) uses advanced imaging technology to better define the tumor target and is the key to reducing and ultimately eliminating the uncertainties. The purpose of this article is to summarize recent advancements in IGRT and discussed various practical issues related to the implementation of the new imaging techniques available to radiation oncology community. We introduce various new IGRT concepts and approaches, and hope to provide the reader with a comprehensive understanding of the emerging clinical IGRT technologies. Some important research topics will also be addressed.

Xing Lei [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States)]. E-mail: lei@reyes.stanford.edu; Thorndyke, Brian [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); Schreibmann, Eduard [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); Yang Yong [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); Li, T.-F. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); Kim, Gwe-Ya [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); Luxton, Gary [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); Koong, Albert [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States)

2006-07-01

93

Focal Therapy, Differential Therapy, and Radiation Treatment for Prostate Cancer  

PubMed Central

Focal and differential therapy represent an approach to improve the therapeutic ratio of prostate cancer treatments. This concept is a shift from treating the whole gland to intensely treating the portion of the gland that contains significant tumor. However, there are many challenges in the move towards focal approaches. Defining which patients are suitable candidates for focal therapy approaches is an area of significant controversy, and it is likely that additional data from imaging or detailed biopsy methods is needed in addition to traditional risk factors. A number of methods have been suggested, and imaging with multiparametric MRI and transperineal template mapping biopsy have shown promise. The approach of differential therapy where the entire prostate is treated to a lower intensity and the tumor areas to high intensity is also discussed in detail. Radiation therapy is a well suited modality for the delivery of differential therapy. Data in the literature using external beam radiation, high dose rate brachytherapy, and low-dose rate brachytherapy for differential therapy are reviewed. Preliminary results are encouraging, and larger studies and randomized controlled trials are needed to validate this approach. PMID:22666239

Jain, Anudh K.; Ennis, Ronald D.

2012-01-01

94

Ocular neuromyotonia after radiation therapy  

SciTech Connect

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

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

1986-12-15

95

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

96

Radiation Therapy for Breast Cancer  

MedlinePLUS

... drugs may be combined to get the best outcome. The dose and schedule for treatment varies, but ... ect your options for reconstruction or the cosmetic outcome. Discuss with your surgeon and radiation oncologist to ...

97

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

98

Respiratory Motion Prediction in Radiation Therapy  

NASA Astrophysics Data System (ADS)

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

Vedam, Sastry

99

Postoperative Radiation Therapy for Parotid Mucoepidermoid Carcinoma  

PubMed Central

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

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

2014-01-01

100

Biomarkers of plaque instability.  

PubMed

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

Shah, P K

2014-12-01

101

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

PubMed

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

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

2015-03-01

102

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

NASA Astrophysics Data System (ADS)

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

Daudon, M.; Bazin, D.

2013-03-01

103

21 CFR 892.5770 - Powered radiation therapy patient support assembly.  

Code of Federal Regulations, 2010 CFR

... false Powered radiation therapy patient support assembly. 892.5770 ...5770 Powered radiation therapy patient support assembly. (a) Identification. A powered radiation therapy patient support assembly is an...

2010-04-01

104

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

105

Glossodynia after radiation therapy and chemotherapy  

SciTech Connect

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

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

1989-10-01

106

Precise positioning of patients for radiation therapy  

Microsoft Academic Search

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

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

1982-01-01

107

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 ...

108

Protons -- The Future of Radiation Therapy?  

NASA Astrophysics Data System (ADS)

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

Avery, Steven

2007-03-01

109

Comparison of particle-radiation-therapy modalities  

SciTech Connect

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

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

1981-01-01

110

Experimental ruthenium plaque therapy of amelanotic and melanotic melanomas in the hamster eye.  

PubMed

The effects of beta-radiation on melanoma implanted into the hamster's eye were investigated. Two Bomirski hamster melanomas (BHMs), differing in their melanin content, were compared with regard to their radiosensitivity to ruthenium-106 (106Ru) radiation. Tumours growing in the iris were irradiated with 3, 6 or 10 Gy of 106Ru given as a single dose or in four fractions at 24 h Intervals. Tumour growth kinetics and distant metastases were studied, and the eyeballs were examined histologically. Dose-dependent delay of tumour growth was observed in both melanomas. After treatment with a dose of 6 Gy, the Ab amelanotic tumours grew 2.6 times slower, and the Ma melanotic tumours 1.4 times slower than untreated ones. The location of metastases differed in the two tested lines--pigmented metastases were found mainly in the lungs, while unpigmented metastases were found mainly in the kidneys. Histopathological analysis showed signs of blood vessel damage such as endothelial cells swelling, erythrocyte extravasation and tumour necrosis. This last finding increased with the rising dose of beta-radiation. Pigmented tumours were found to be two times more resistant to beta-radiation than amelanotic ones. The pattern of metastases of BHMs is determined by the type of melanoma (Ab or Ma). Exposure to beta-radiation from 106Ru did not significantly affect either the number or size of metastases except at a dose of 10 Gy. This dose caused a statistically significant decrease in the number of metastases in the Ma melanotic subline. PMID:10711637

Urbanska, K; Romanowska-Dixon, B; Elas, M; Pajak, S; Paziewski, E; Bryk, J; Kukielczak, B; Slominski, A; Zygulska-Mach, H; Lukiewicz, S

2000-02-01

111

Radiation therapy for orbital lymphoma  

SciTech Connect

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

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

2005-11-01

112

Post-operative radiation therapy  

PubMed Central

In completely resected non-small-cell lung cancer (NSCLC) patients with pathologically involved mediastinal lymph nodes (N2), administration of adjuvant platinum-based chemotherapy is now considered the standard of care, based on level 1 evidence. The role of post-operative radiotherapy (PORT) in this group of patients remains controversial. In the PORT meta-analysis published in 1998, the conclusions were that if adjuvant radiotherapy was detrimental to patients with early-stage completely resected NSCLC, the role of PORT in the treatment of tumours with N2 involvement was unclear and further research was warranted. Recent retrospective and non-randomized studies as well as subgroup analyses of recent randomized trials evaluating adjuvant chemotherapy, provide evidence of the possible benefit of PORT in patients with mediastinal nodal involvement. The question of PORT indication is also valid for those patients with proven N2 disease who undergo neo-adjuvant chemotherapy followed by surgery. The risk of local recurrence for N2 patients varies between 20% and 60%. Based on currently available data, PORT should be discussed for fit patients with completely resected NSCLC with N2 nodal involvement, within a multidisciplinary setting, preferably after completion of adjuvant chemotherapy or after surgery if patients have had neo-adjuvant chemotherapy. There is need for new randomized evidence to reassess PORT using modern three-dimensional conformal radiation technique, with attention to normal organ sparing, particularly lung and heart, to reduce the possible additional toxicity. Randomized evidence is needed. A new large international multi-institutional randomized trial Lung ART evaluating PORT in this patient population is now underway, as well as a Chinese study comparing postoperative sequential chemotherapy followed by radiotherapy versus adjuvant chemotherapy alone.

Paumier, Amaury

2013-01-01

113

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

114

Advances in radiation therapy for oncologic pain  

Microsoft Academic Search

Pain is a feared component of cancer for a patient. The patient’s prior experience with cancer pain will affect how he or\\u000a she deals with ongoing and acute onset new pain. Radiation therapy has been and continues to be a major component in the management\\u000a of cancer pain. New technologies are rapidly becoming available that will allow more specific and

Jason K. Rockhill

2007-01-01

115

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

SciTech Connect

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

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

2011-07-01

116

Vulnerable Plaque  

MedlinePLUS

... pH of plaque. Can vulnerable plaque be prevented? Patients can lower their C-reactive protein levels in the same ways that they can cut their heart attack risk: take aspirin, eat a proper diet, quit smoking, and begin an exercise program. Researchers also think that obesity and diabetes ...

117

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. PMID:22511689

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

2013-01-01

118

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

Microsoft Academic Search

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

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

2008-01-01

119

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

Microsoft Academic Search

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

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

120

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. PMID:23717005

Gupta, Ashok Kumar; Pandey, Shyam Sunder

2013-01-01

121

Chronic neuroendocrinological sequelae of radiation therapy  

SciTech Connect

A variety of neuroendocrine disturbances are observed following treatment with external radiation therapy when the hypothalamic-pituitary axis (HPA) is included in the treatment field. Radiation-induced abnormalities are generally dose dependent and may develop many years after irradiation. Growth hormone deficiency and premature sexual development can occur following doses as low as 18 Gy fractionated radiation and are the most common neuroendocrine problems noted in children. Deficiency of gonadotropins, thyroid stimulating hormone, and adrenocorticotropin are seen primarily in individuals treated with > 40 Gy HPA irradiation. Hyperprolactinemia can be seen following high-dose radiotherapy (>40 Gy), especially among young women. Most neuroendocrine disturbances that develop as a result of HPA irradiation are treatable; patients at risk require long-term endocrine follow-up. 23 refs., 6 figs., 2 tabs.

Sklar, C.A. [Memorial Sloan-Kettering Cancer Center, New York, NY (United States)] [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Constine, L.S. [Univ. of Rochester Medical Center, Rochester, NY (United States)] [Univ. of Rochester Medical Center, Rochester, NY (United States)

1995-03-30

122

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

Microsoft Academic Search

The purpose of this study is to evaluate the interscan, interobserver and intraobserver agreement for coronary plaque detection,\\u000a and characterization using low radiation dose high-pitch spiral acquisition coronary CT angiography (CTA). Two experienced\\u000a observers independently evaluated coronary CTA datasets from 50 consecutive patients undergoing two 128-slice dual source\\u000a CT scans within 12 days. Mean (±SD) estimated radiation exposure was 1.5 ± 0.2 mSv per

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

123

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

124

Optical Tracking Technology in Stereotactic Radiation Therapy  

SciTech Connect

The last decade has seen the introduction of advanced technologies that have enabled much more precise application of therapeutic radiation. These relatively new technologies include multileaf collimators, 3-dimensional conformal radiotherapy planning, and intensity modulated radiotherapy in radiotherapy. Therapeutic dose distributions have become more conformal to volumes of disease, sometimes utilizing sharp dose gradients to deliver high doses to target volumes while sparing nearby radiosensitive structures. Thus, accurate patient positioning has become even more important, so that the treatment delivered to the patient matches the virtual treatment plan in the computer treatment planning system. Optical and image-guided radiation therapy systems offer the potential to improve the precision of patient treatment by providing a more robust fiducial system than is typically used in conventional radiotherapy. The ability to accurately position internal targets relative to the linac isocenter and to provide real-time patient tracking theoretically enables significant reductions in the amount of normal tissue irradiated. This report reviews the concepts, technology, and clinical applications of optical tracking systems currently in use for stereotactic radiation therapy. Applications of radiotherapy optical tracking technology to respiratory gating and the monitoring of implanted fiducial markers are also discussed.

Wagner, Thomas H. [Department of Radiation Physics, M. D. Anderson Cancer Center Orlando, Orlando, FL (United States)]. E-mail: thomas.wagner@orhs.org; Meeks, Sanford L. [Department of Radiation Physics, M. D. Anderson Cancer Center Orlando, Orlando, FL (United States); Bova, Frank J. [Department of Neurological Surgery, University of Florida, Gainesville, FL (United States); Friedman, William A. [Department of Neurological Surgery, University of Florida, Gainesville, FL (United States); Willoughby, Twyla R. [Department of Radiation Physics, M. D. Anderson Cancer Center Orlando, Orlando, FL (United States); Kupelian, Patrick A. [Department of Radiation Physics, M. D. Anderson Cancer Center Orlando, Orlando, FL (United States); Tome, Wolfgang [Department of Human Oncology, University of Wisconsin, Madison, WI (United States)

2007-07-01

125

Methods for implementing microbeam radiation therapy  

DOEpatents

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

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

2007-03-20

126

Radiation Macular Edema after Ru-106 Plaque Brachytherapy for Choroidal Melanoma Resolved by an Intravitreal Dexamethasone 0.7-mg Implant  

PubMed Central

Purpose To report the effective treatment of radiation macular edema following ruthenium-106 plaque brachytherapy for a choroidal melanoma with a dexamethasone 0.7-mg (Ozurdex®) intravitreal implant. Methods An interventional case report with optical coherence tomography (OCT) scans. Results A 65-year-old Caucasian woman was suffering from radiation macular edema following ruthenium-106 plaque brachytherapy for a choroidal melanoma on her left eye. She had undergone one intravitreal injection of 0.5 mg bevacizumab (Avastin®, Genentech/Roche) in the following months without functional or anatomical improvement. Seven months after the development of radiation macular edema, she received a single intravitreal injection of dexamethasone 0.7 mg (Ozurdex). Four weeks following the injection, her best-corrected visual acuity improved from 0.3 to 0.5. Radiation macular edema resolved with a reduction of central retinal thickness from 498 ?m before Ozurdex injection to 224 ?m after Ozurdex injection, as measured by OCT scan. Conclusion Dexamethasone 0.7 mg (Ozurdex) has proven to be an effective treatment option in retinal vein occlusion and noninfectious uveitis. It can also be considered as off-label treatment in radiation macular edema following ruthenium-106 plaque brachytherapy for a choroidal melanoma. PMID:22529805

Russo, Andrea; Avitabile, Teresio; Uva, Maurizio; Faro, Salvatore; Franco, Livio; Sanfilippo, Marisa; Gulisano, Seby; Toro, Mario; De Grande, Vittorio; Rametta, Stefania; Foti, Laura; Longo, Antonio; Reibaldi, Michele

2012-01-01

127

Intraoperative Radiation Therapy in Gastric Cancer  

PubMed Central

Abstract Gastric cancer is one of the most common malignancies worldwide. Although surgery is the only potential curative treatment, the overall survival results remain poor due to the high risks of recurrence, so scientists developed new aggressive adjuvant therapies. That is how the IORT appeared. IORT is a technique designed to provide a large radiation dose to a target tissue considered of being "at risk" to develop recurrence. In this review we resume recent publications which debate the use, efficacy and the overall survival after IORT. PMID:25408715

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

2014-01-01

128

Prostatic carcinoma: rectal bleeding after radiation therapy  

SciTech Connect

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

Kagan, A.R.; Steckel, R.J. (eds.)

1981-06-01

129

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

130

Adjuvant postoperative radiation therapy for colonic carcinoma.  

PubMed Central

One hundred thirty-three patients with Stage B2, B3, and C colonic carcinoma had resection for curative intent followed by adjuvant postoperative radiotherapy to the tumor bed. The 5-year actuarial local control and disease-free survival rates for these 133 patients were 82% and 61%, respectively. Stage for stage, the development of local regional failure was reduced for patients receiving postoperative radiotherapy compared with a historic control series. Local recurrence occurred in 8%, 21%, and 31% of patients with Stage B3, C2, and C3 tumors who had radiation therapy, respectively, whereas the local failure rates were 31%, 36%, and 53% in patients treated with surgery alone. There was a 13% and 12% improvement in the 5-year disease-free survival rate in the patients with Stage B3 and C3 lesions who had radiotherapy compared with the historic controls. For patients with Stage C disease, local control and disease-free survival rates decreased progressively with increasing nodal involvement; however, local control and disease-free survival rates were higher in the patients who had radiotherapy than in those who had surgery alone. Failure patterns in the patients who had radiotherapy did not show any notable changes compared with those for patients who had surgery alone. Postoperative radiation therapy for Stage B3, C2, and C3 colonic carcinoma is a promising treatment approach that deserves further investigation. PMID:3689006

Willett, C G; Tepper, J E; Skates, S J; Wood, W C; Orlow, E C; Duttenhaver, J R

1987-01-01

131

Mapping the literature of radiation therapy  

PubMed Central

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

Delwiche, Frances A.

2013-01-01

132

Collimator design for experimental minibeam radiation therapy  

SciTech Connect

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

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

2011-04-15

133

Radiation Therapy for Colon, Rectum and Anus Cancers  

MedlinePLUS

... Prostate Skin Upper GI Latest Research Find a Radiation Oncologist Last Name: Facility: City: State: Zip Code: ... Treating Colon, Rectum and Anus Cancers External Beam Radiation Therapy Possible Side Effects Caring for Yourself During ...

134

Organ-sparing radiation therapy for head and neck cancer.  

PubMed

To improve locoregional tumor control and survival in patients with locally advanced head and neck cancer (HNC), therapy is intensified using altered fractionation radiation therapy or concomitant chemotherapy. However, intensification of therapy has been associated with increased acute and late toxic effects. The application of advanced radiation techniques, such as 3D conformal radiation therapy and intensity-modulated radiation therapy, is expected to improve the therapeutic index of radiation therapy for HNC by limiting the dose to critical organs and possibly increasing locoregional tumor control. To date, Review articles have covered the prevention and treatment of radiation-induced xerostomia and dysphagia, but few articles have discussed the prevention of hearing loss, brain necrosis, cranial nerve palsy and osteoradionecrosis of the mandible, which are all potential complications of radiation therapy for HNC. This Review describes the efforts to prevent therapy-related complications by presenting the state of the art evidence regarding advanced radiation therapy technology as an organ-sparing approach. PMID:21788974

Wang, XiaoShen; Hu, ChaoSu; Eisbruch, Avraham

2011-11-01

135

[Stereotactic body radiation therapy: uncertainties and margins].  

PubMed

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

Lacornerie, T; Marchesi, V; Reynaert, N

2014-01-01

136

[Whole brain radiation therapy for brain metastases: Advantages and controversies].  

PubMed

Whole brain radiation therapy is the angular stone of the brain metastasis radiation therapy. This treatment allows reaching two goals, potentially curative for in place metastasis and prophylactic in the rest of brain tissue. However, these two advantages can be disputed and in light of the same data opposite conclusions could be drawn. PMID:25662599

Noël, G; Tallet, A; Truc, G; Bernier, V; Feuvret, L; Assouline, A; Antoni, D; Verrelle, P; Mazeron, J-J; Mornex, F; Dhermain, F

2015-02-01

137

Intensity Modulated Beam Radiation Therapy Dose Optimization with Multiobjective  

E-print Network

will be di- agnosed with cancer. Half of these will be treated with radiation therapy [1]. In teletherapy the patient body the beams deposit en- ergy. Cancer cells have a smaller probability than healthy normal cellsIntensity Modulated Beam Radiation Therapy Dose Optimization with Multiobjective Evolutionary

Coello, Carlos A. Coello

138

Patient alignment device for cobalt-60 radiation therapy  

SciTech Connect

A technique has been described for fabrication of a radiation therapy stent that can help to stabilize the head when adjustable alignment devices are used to position a patient during radiation therapy. The technique can save time for the radiotherapist, enhance accuracy in treatment, increase patient comfort, and save the dentist time in stent fabrication.

Engelmeier, R.L.

1987-11-01

139

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

PubMed

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

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

2013-09-01

140

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

PubMed Central

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

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

2014-01-01

141

Heavy-ion sources for radiation therapy  

NASA Astrophysics Data System (ADS)

The usefulness of particle beams for radiation therapy has been well and widely recognized. For the cure of cancer patients, many accelerator facilities have already been utilized, and some new facilities are now being put into operation, or are under construction. Considering the medical and biological requirements, light heavy ions with an energy of several hundred MeV/nucleon are regarded as being the most suitable species. A reasonable choice to this end is an accelerator complex, for an example, one comprising an ion source, an injector linac, and a synchrotron. The ion source is of great importance, since its characteristics strongly affect the overall performance of the accelerator system. A pulsed Penning source (PIGIS) has been successfully used at Lawrence Berkeley Laboratory. Recently, at the National Institute of Radiological Sciences a low-duty pulsed PIGIS for the heavy-ion medical accelerator in Chiba (HIMAC) has been developed; it has both a long lifetime and a high peak intensity. As other types of ion sources, an electron-beam ion source (EBIS) and an electron-cyclotron-resonance ion source (ECRIS) are being developed at several laboratories. An EBIS is basically a pulsed source, and is being successfully used at Saclay. By using an after-glow mode, two ECRISs have made remarkable progress at Grenoble and the Grand Accelerateur National d'Ions Lourds; similar tests are proceeding for the Schwer-Ionen Synchrotron at the Gesellschaft for Schwer-Ionenforschung, the booster at Centre d'Europeen de Recherche Nucleaire, and the HIMAC. These different types of heavy-ion sources are discussed from the viewpoint of their application to radiation therapy.

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

1994-10-01

142

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. PMID:23300905

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

2012-01-01

143

21 CFR 892.5770 - Powered radiation therapy patient support assembly.  

Code of Federal Regulations, 2013 CFR

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2013-04-01

144

21 CFR 892.5710 - Radiation therapy beam-shaping block.  

Code of Federal Regulations, 2013 CFR

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2013-04-01

145

21 CFR 892.5770 - Powered radiation therapy patient support assembly.  

Code of Federal Regulations, 2012 CFR

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2012-04-01

146

21 CFR 892.5710 - Radiation therapy beam-shaping block.  

Code of Federal Regulations, 2011 CFR

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2011-04-01

147

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

Code of Federal Regulations, 2014 CFR

...false Medical charged-particle radiation therapy system. 892.5050 ...5050 Medical charged-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system is a device...

2014-04-01

148

21 CFR 892.5710 - Radiation therapy beam-shaping block.  

Code of Federal Regulations, 2012 CFR

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2012-04-01

149

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

Code of Federal Regulations, 2012 CFR

...false Medical charged-particle radiation therapy system. 892.5050 ...5050 Medical charged-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system is a device...

2012-04-01

150

21 CFR 892.5770 - Powered radiation therapy patient support assembly.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Powered radiation therapy patient support assembly...Devices § 892.5770 Powered radiation therapy patient support assembly. (a) Identification. A powered radiation therapy patient support...

2011-04-01

151

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

Code of Federal Regulations, 2010 CFR

...false Medical charged-particle radiation therapy system. 892.5050 ...5050 Medical charged-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system is a device...

2010-04-01

152

21 CFR 892.5770 - Powered radiation therapy patient support assembly.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Powered radiation therapy patient support assembly...Devices § 892.5770 Powered radiation therapy patient support assembly. (a) Identification. A powered radiation therapy patient support...

2014-04-01

153

21 CFR 892.5710 - Radiation therapy beam-shaping block.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Radiation therapy beam-shaping block. 892...Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification. A radiation therapy beam-shaping block...

2014-04-01

154

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

Code of Federal Regulations, 2011 CFR

...false Medical charged-particle radiation therapy system. 892.5050 ...5050 Medical charged-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system is a device...

2011-04-01

155

21 CFR 892.5710 - Radiation therapy beam-shaping block.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Radiation therapy beam-shaping block. 892...Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification. A radiation therapy beam-shaping block...

2010-04-01

156

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

Code of Federal Regulations, 2013 CFR

...false Medical charged-particle radiation therapy system. 892.5050 ...5050 Medical charged-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system is a device...

2013-04-01

157

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

158

Intestinal strictures complicating preoperative radiation therapy followed by radical cystectomy  

SciTech Connect

Between January 1975 and January 1981, 100 patients with invasive bladder cancer were evaluated for therapy. Of these patients 51 were selected for treatment with preoperative radiation therapy followed by radical cystectomy. Of 36 patients who actually completed the integrated therapy 4 (11 per cent) had clinical intestinal strictures. Three strictures occurred more than 24 months and 1 less than 6 months postoperatively. Strictures involved the colon in 3 cases and the ileum in 1. An operation was required in 2 cases. We present these 4 cases, and discuss the pathophysiology and treatment of the radiation-injured intestine. Our experience suggests that preoperative radiation therapy in conjunction with radical cystectomy may be associated with the development of clinically significant bowel injury. This factor should be considered in the decision to combine preoperative radiation therapy with radical cystectomy in the treatment of bladder cancer.

Hillyard, R.W. Jr.; el-Mahdi, A.M.; Schellhammer, P.F.

1986-07-01

159

Radiation pneumonitis after stereotactic radiation therapy for lung cancer  

PubMed Central

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

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

2014-01-01

160

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

161

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

162

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

PubMed

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

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

2010-01-01

163

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

164

Overcoming the hypoxic barrier to radiation therapy with anaerobic bacteria.  

PubMed

The low level of oxygenation within tumors is a major cause of radiation treatment failures. We theorized that anaerobic bacteria that can selectively destroy the hypoxic regions of tumors would enhance the effects of radiation. To test this hypothesis, we used spores of Clostridium novyi-NT to treat transplanted tumors in mice. The bacteria were found to markedly improve the efficacy of radiotherapy in several of the mouse models tested. Enhancement was noted with external beam radiation derived from a Cs-137 source, systemic radioimmunotherapy with an I-131-conjugated monoclonal antibody, and a previously undescribed form of experimental brachytherapy using plaques loaded with I-125 seeds. C. novyi-NT spores added little toxicity to the radiotherapeutic regimens, and the combination resulted in long-term remissions in a significant fraction of animals. PMID:14657371

Bettegowda, Chetan; Dang, Long H; Abrams, Ross; Huso, David L; Dillehay, Larry; Cheong, Ian; Agrawal, Nishant; Borzillary, Scott; McCaffery, J Michael; Watson, E Latice; Lin, Kuo-Shyan; Bunz, Fred; Baidoo, Kwamena; Pomper, Martin G; Kinzler, Kenneth W; Vogelstein, Bert; Zhou, Shibin

2003-12-01

165

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

166

Dynamic optimization of fractionation schedules in radiation therapy  

E-print Network

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

Ramakrishnan, Jagdish

2013-01-01

167

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

PubMed Central

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

2011-01-01

168

Persistence of endometrial activity after radiation therapy for cervical carcinoma  

SciTech Connect

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

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

1985-12-01

169

A Shape Relationship Descriptor for Radiation Therapy Planning  

E-print Network

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

Kazhdan, Michael

170

OPTIMIZING THE DELIVERY OF RADIATION THERAPY TO CANCER PATIENTS \\Lambda  

E-print Network

OPTIMIZING THE DELIVERY OF RADIATION THERAPY TO CANCER PATIENTS \\Lambda DAVID M. SHEPARD y therapy, much of the research is aimed at developing new and innovative techniques for treating cancer growing and dividing. This is true of both cancer cells and normal cells. Radiotherapy is a useful tool

Ferris, Michael C.

171

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. (Hyogo Coll. of Medicine, Japan); Shimada, T.; Miura, T.; Imajyo, Y.

1983-03-01

172

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

173

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

E-print Network

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

Vu, An T. (An Thien)

2011-01-01

174

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

175

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

176

An Investigation of Vascular Strategies to Augment Radiation Therapy  

NASA Astrophysics Data System (ADS)

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

El Kaffas, Ahmed Nagy

177

Late effects of radiation therapy on the gastrointestinal tract  

Microsoft Academic Search

Late gastrointestinal complications of radiation therapy have been recognized but not extensively studied. In this paper, the late effects of radiation on three gastrointestinal sites, the esophagus, the stomach, and the bowel, are described. Esophageal dysmotility and benign stricture following esophageal irradiation are predominantly a result of damage to the esophageal wall, although mucosal ulcerations also may persist following high-dose

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

1995-01-01

178

Argon plasma coagulation therapy for hemorrhagic radiation proctosigmoiditis  

Microsoft Academic Search

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

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

1999-01-01

179

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

180

Radiation therapy for adjunctive treatment of adrenal cortical carcinoma  

SciTech Connect

Adrenocortical carcinoma is a rare disease which is primarily approached surgically. There have been few reports of the efficacy of radiation therapy and, for the most part, these have been anecdotal. This paper reports on the potential adjuvant role of radiation therapy after surgical excision of primary adrenal cortical carcinoma and also comments about the efficacy of palliative radiation therapy for metastases. We have identified eight patients treated for adrenal cortical carcinomas at Hahnemann University Hospital (HUH) from 1962 until the present and have also identified five patients with the same diagnosis at Philadelphia General Hospital (PGH) from 1962 until its close in 1975. These two groups are examined separately. In the PGH group, in which two patients were diagnosed at autopsy and only one patient was treated by radiation therapy, the median survival was between 0 and 1 month for Stage IV disease with the only patient surviving to 6 months being that patient receiving radiation therapy. In the HUH group, five of eight patients were treated adjunctively after diagnosis, one was not and two received palliative therapy. The median survival for treated Stage III patients was between 34 months and 7 years. The suggestion, based on a limited patient series, is that patients treated postoperatively to the tumor bed and nodal areas in Stage III disease may have improved survival over historic series and improved local control.

Markoe, A.M.; Serber, W.; Micaily, B.; Brady, L.W. (Hahnemann Univ. Medical School and Hospital, Philadelphia, PA (USA))

1991-04-01

181

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

182

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

183

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

Microsoft Academic Search

Severe psoriasis is associated with significant cardiovascular mortality. We therefore investigated the effects of systemic\\u000a therapy on the cardiovascular risk of psoriasis patients. Thirteen consecutive patients receiving fumaric acid esters were\\u000a included and followed for 24 weeks both clinically and by means of laboratory monitoring, 10 completed the study. Eight of\\u000a ten patients showed a PASI-50 response. Two of three patients

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

184

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

185

Considering the role of radiation therapy for gastrointestinal stromal tumor  

PubMed Central

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

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

2014-01-01

186

Recent advances in radiation therapy for head and neck cancer.  

PubMed

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, fractionated stereotactic radiotherapy, charged-particle radiotherapy, neutron-beam radiotherapy, and brachytherapy have helped to improve this outlook even further. These recent advances allow for a higher dose to be delivered to the tumor while minimizing the dose delivered to the surrounding normal tissue. This article provides an update of the new developments in radiotherapy in the management of head and neck cancers. PMID:17085946

Bangalore, Madan; Matthews, Shirnett; Suntharalingam, Mohan

2007-01-01

187

Management of Chemotherapeutic Agent Extravasation and Radiation Therapy Adverse Effects  

Microsoft Academic Search

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

Ida K. Fox; Howard N. Langstein

188

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

189

Optimization under uncertainty in radiation therapy  

E-print Network

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

Chan, Timothy Ching-Yee

2007-01-01

190

Complications following radiation therapy to the head  

SciTech Connect

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

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

1986-03-01

191

The physical basis and future of radiation therapy  

PubMed Central

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

Bortfeld, T; Jeraj, R

2011-01-01

192

Enhanced radiation therapy with internalized polyelectrolyte modified nanoparticles  

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

193

Stereotactic Body radiation therapy for liver tumors with or without rotational intensity modulated radiation therapy  

PubMed Central

Background To evaluate the feasibility and efficacy of Stereotactic body radiation therapy (SBRT) for primary liver lesions and liver metastases treated with linear accelerators with or without rotational Intensity Modulated RadioTherapy (IMRT). Methods Patients with either hepatocellular carcinoma, cholangiocarcinoma or metastatic liver lesions who had one to three lesions treated with SBRT in a single institution were retrospectively reviewed. Tumor response was evaluated according to EASL criteria 3 months after SBRT completion using MRI and/or abdominal CT scan. Responses were categorised as: Stable Disease (SD), Partial Response (PR), Complete Response (CR), Local Progression or Distant Progression in cases of new intra-hepatic lesions out-of-field or extra-hepatic metastases. Local Control (LC), Progression Free Survival (PFS), Overall Survival (OS) and treatment-related toxicities are reported. Results Between 2007 and 2012, 20 patients with a total of 24 lesions were treated with SBRT. Fourteen patients presented hepatocellular carcinoma (HCC), the others had either metastatic lesions from colorectal cancer (CRC) or cholangiocarcinoma. The median diameter of the lesions was 23 mm (5–98). The dose per fraction ranged from 6 to 20 Gy with a median total dose of 60 Gy (range: 36–60 Gy). The dose was prescribed to the 80% isodose line covering the PTV. The median follow-up was 24 months (15.7-29.7). The actuarial LC rate was 78% for patients with HCC and 83% for those with adenocarcinoma and cholangiocarcinoma. Median OS was 37 months and OS rates were 83% at 12 and 24 months for HCC and 100% for adenocarcinoma. PFS was 54% for HCC and 50% for other types of tumors at 24 months. Acute grade 3–4 toxicities occurred in 2 patients; a small proportion of the other patients experienced grade 1 or 2 toxicities. Conclusions SBRT provides excellent local control with minimal side effects in selected patients. PMID:24279802

2013-01-01

194

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

SciTech Connect

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

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

2012-11-15

195

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

196

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

197

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

E-print Network

your anatomical knowledge to clinical practice. You will also need to be self-directed to access Therapy Practice · Academic units must be studied concurrently or as a pre-requisite to studying clinical) Principles of Imaging for Advanced Radiation Therapy Practice 1 (Academic Unit) Duration 13 weeks Delivery

Albrecht, David

198

Psoriasis (chronic plaque)  

PubMed Central

Introduction Psoriasis is a chronic inflammatory skin disease that affects 1% to 3% of the population, in some people causing changes to the nails and joints as well as skin lesions. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of non-drug (other than ultraviolet light), topical drug, ultraviolet light, and systemic drug treatments for chronic plaque psoriasis? What are the effects of combined treatment with drugs plus ultraviolet light for chronic plaque psoriasis? What are the effects of combined systemic plus topical drug treatments for chronic plaque psoriasis? We searched: Medline, Embase, The Cochrane Library, and other important databases up to August 2007 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 122 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: acupuncture, adding calcipotriol (topical) to psoralen plus ultraviolet light A or ultraviolet light B, adding oral retinoids to psoralen plus ultraviolet A (PUVA), alefacept, balneotherapy, ciclosporin, dithranol, T cell-targeted therapies, cytokine blocking agents, emollients (alone or plus ultraviolet light B), etanercept, fish oil supplementation, fumaric acid derivatives, Goeckerman treatment, heliotherapy, infliximab, Ingram regimen, keratolytics (salicylic acid, urea), leflunomide, methotrexate, oral pimecrolimus, oral retinoids (alone or with ultraviolet light B), phototherapy plus balneotherapy, psoralen plus ultraviolet A, psychotherapy, systemic drug treatments plus topical vitamin D derivatives, tars, tazarotene, topical corticosteroids (alone or plus oral retinoids), topical Vitamin D derivatives, ultraviolet light A, and ultraviolet light B. PMID:19445765

2009-01-01

199

Hypofractionated radiation therapy for prostate cancer: biologic and technical considerations  

PubMed Central

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

Sanfilippo, Nicholas J; Cooper, Benjamin T

2014-01-01

200

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

PubMed

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

Lapierre, A; Martin, F; Lapeyre, M

2014-10-01

201

Late Gastrointestinal Toxicities Following Radiation Therapy for Prostate Cancer  

PubMed Central

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

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

2011-01-01

202

Radiation therapy of retroperitoneal soft tissue sarcomas  

Microsoft Academic Search

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

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

1984-01-01

203

Intensity-Modulated Radiation Therapy (IMRT)  

MedlinePLUS

... safely be delivered to tumors with fewer side effects compared with conventional radiotherapy techniques. IMRT also has the potential to reduce ... as well as from radiation damage to healthy cells in the treatment area. The number and severity of side effects you experience will depend on the type of ...

204

Radiation retinopathy. [Complications of local tumor therapy  

Microsoft Academic Search

The records were reviewed of all patients treated with irradiation to the eye at the University of California, San Francisco, between 1960 and 1975. Eight patients were identified who had developed radiation retinopathy 1 to 3 years postrirradiation. Lesions included retinal vascular occlusions, hemorrhages, microaneurysms, exudates, neovascularization, vitreous hemorrhage, retinal detachments, and optic atrophy with blindness. Four patients had received

W. M. Wara; A. R. Irvine; R. E. Neger; E. L. Jr. Howes; T. L. Phillips

1979-01-01

205

Hemodynamic responses to antivascular therapy and ionizing radiation assessed  

E-print Network

Hemodynamic responses to antivascular therapy and ionizing radiation assessed by diffuse optical. of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104 Dept. of Radiology and Dept. of Physics and Astronomy, University of Pennsylvania, PA, 19104 Dept. of Medicine and the Abramson Cancer

Yodh, Arjun G.

206

Sexual function after surgical and radiation therapy for cervical carcinoma  

Microsoft Academic Search

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

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

1982-01-01

207

A Leaf Sequencing Software for Intensity-Modulated Radiation Therapy  

Microsoft Academic Search

This paper presents a leaf sequencing software called SLS (static leaf sequencing) for intensity-modulated radiation therapy (IMRT). SLS seeks to produce improved clinical IMRT treatment plans by (1) shortening their treatment times and (2) minimizing their machine delivery errors. Our SLS software is implemented using the C programming language on Linux workstations and is designed as a separate module to

Shuang Luan; Chao Wang; Danny Z. Chen; Xiaobo Sharon Hu

2006-01-01

208

Miniature scintillating detector for small field radiation therapy D. Letourneaua)  

E-print Network

Miniature scintillating detector for small field radiation therapy D. Le´tourneaua) Centre curves, profiles, and dose rate of treatment beams are difficult to obtain with conventional detectors because of loss of lateral elec- tronic equilibrium and volume averaging. A scintillating detector

Pouliot, Jean

209

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.

210

Megavoltage Beam Properties Affecting Patient Dose in Radiation Therapy  

Microsoft Academic Search

Certain properties of megavoltage beams have remained of concern in radiation therapy. This investigation is directed towards a better characterization of the problems presented by contaminant electrons in these photon beams, by their spectral distribution and by their interaction in a specific target tissue where heterogeneity poses a particular clinical problem. Two megavoltage beams, a ^{60}CO and a 6 MV,

Nnaemeka C. Ikoro

1988-01-01

211

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

E-print Network

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

Sheridan, Scott

212

How important is breathing in radiation therapy of the thorax  

Microsoft Academic Search

Repeated computed tomographic (CT) scanning has been used to assess the effect of quiet breathing on the dosimetry in radiation therapy of the thorax. Density variations as great as 80 CT numbers (8% of the density of water) have been observed between the inspiration and expiration limits of quiet breathing, and movement of anatomical points of greater than 1 cm

R. Mark Henkelman; Katherine Mah

1982-01-01

213

Laser therapy for severe radiation-induced rectal bleeding  

SciTech Connect

Four patients with chronic hematochezia and transfusion-dependent anemia from postradiation rectal vascular lesions were successfully managed by endoscopic laser coagulation. In all four patients, symptomatic, hematologic, and endoscopic improvement was evident. Laser therapy for severe radiation-induced rectal bleeding seems to be safe and efficacious and should be considered before surgical intervention.

Ahlquist, D.A.; Gostout, C.J.; Viggiano, T.R.; Pemberton, J.H.

1986-12-01

214

Factors influencing radiation therapy student clinical placement satisfaction  

PubMed Central

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

Bridge, Pete; Carmichael, Mary-Ann

2014-01-01

215

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

PubMed Central

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

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

2013-01-01

216

Complementary Strategies for the Management of Radiation Therapy Side Effects  

PubMed Central

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

Stubbe, Christine E.; Valero, Meighan

2013-01-01

217

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

218

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

PubMed Central

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

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

2013-01-01

219

Radiation Therapy Using Synchrotron Radiation: Preclinical Studies Toward Clinical Trials  

Microsoft Academic Search

After decades of intensive research, high-grade gliomas are still resistant to therapies, including surgery, chemotherapy, and radiotherapy or a combination thereof. The most important advance in the treatment of these tumors has been the introduction of a new chemotherapy drug called temozolomide, in combination with external beam photon irradiation [1]. One of the goals of the association of the CHU\\/UJF\\/INSERM

Jean-François Adam; Jacques Balosso; Laure Bobyk; Anne-Marie Charvet; Pierre Deman; Magali Edouard; Hélène Elleaume; François Estève; Jean-François Le Bas; Julia Rousseau; Raphaël Serduc; Mathias Vautrin; Tanguy Chabrol; Antoine Depaulis; Benoit Pouyatos; José Baruchel; Paul Berkvens; Gilles Berruyer; Audrey Bouchet; Elke Bräuer-Krisch; Alberto Bravin; Thierry Brochard; Dominique Dallery; Géraldine Le Duc; Christian Némoz; Immaculada Martínez-Rovira; Yolanda Prezado; Michel Renier; Herwig Requardt; Mehdi Benkebil; Jean Laissue

2011-01-01

220

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

Microsoft Academic Search

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

Tatiana I. Lingos; Abram Recht; Frank Vicini; Anthony Abner; Barbara Silver; Jay R. Harris

1991-01-01

221

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

222

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.

223

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.

224

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

MedlinePLUS

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

225

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 ...

226

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

MedlinePLUS

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

227

Research Findings on Radiation Hormesis and Radon Therapy  

SciTech Connect

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

Hattori, Sadao

1999-06-06

228

Image guidance and Motion Adaptation in Radiation Therapy  

NASA Astrophysics Data System (ADS)

Modern radiation therapy can achieve a very high level of conformality, meaning that the size and shape of nearly any disease site (such as a tumor) can be irradiated to uniform dose while sparing surrounding normal tissue. However, an inherent limitation in many treatment planning and delivery systems is that the body region under treatment is considered to be static and unchanging. This assumption is false, as there are many processes over varying time scales that change the shape, location, and size of the treatment target and surrounding tissue. Technological advances are now making it feasible to treat tumors adaptively, so that the radiation delivered is modulated in real time to match the changes in the body. These advances will enable more accurate and precise radiation treatments, which should improve cure rates and patient survival times. In this talk, I will present methods for observing the dynamic tumor, determining its changes in shape, size, and position, and delivering adaptive therapy.

Murphy, Martin

2011-10-01

229

Immobilization devices for intensity-modulated radiation therapy (IMRT).  

PubMed

Three-dimensional conformal radiation therapy (3DCRT) and intensity-modulated radiation therapy (IMRT) plans show radiation dose distribution that is highly conformal to the target volume. The successful clinical implementation of these radiotherapy modalities requires precise positioning of the target to avoid a geographical miss. Effective reduction in target positional inaccuracies can be achieved with the proper use of immobilization devices. This paper reviews some of the immobilization devices that have been used and/or have the potential of being used for IMRT. The immobilization devices being reviewed include stereotactic frame, Talon system, thermoplastic molds, Alpha Cradles, and Vac-Lok system. The implementation of these devices at various anatomical sites is discussed. PMID:11417510

Saw, C B; Yakoob, R; Enke, C A; Lau, T P; Ayyangar, K M

2001-01-01

230

Study on neutron radiation field of carbon ions therapy  

E-print Network

Carbon ions offer significant advantages for deep-seated local tumors therapy due to their physical and biological properties. Secondary particles, especially neutrons caused by heavy ion reactions should be carefully considered in treatment process and radiation protection. For radiation protection purposes, the FLUKA Code was used in order to evaluate the radiation field at deep tumor therapy room of HIRFL in this paper. The neutron energy spectra, neutron dose and energy deposition of carbon ion and neutron in tissue-like media was studied for bombardment of solid water target by 430MeV/u C ions. It is found that the calculated neutron dose have a good agreement with the experimental date, and the secondary neutron dose may not exceed one in a thousand of the carbon ions dose at Bragg peak area in tissue-like media.

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

2015-01-01

231

Study on neutron radiation field of carbon ions therapy  

E-print Network

Carbon ions offer significant advantages for deep-seated local tumors therapy due to their physical and biological properties. Secondary particles, especially neutrons caused by heavy ion reactions should be carefully considered in treatment process and radiation protection. For radiation protection purposes, the FLUKA Code was used in order to evaluate the radiation field at deep tumor therapy room of HIRFL in this paper. The neutron energy spectra, neutron dose and energy deposition of carbon ion and neutron in tissue-like media was studied for bombardment of solid water target by 430MeV/u C ions. It is found that the calculated neutron dose have a good agreement with the experimental date, and the secondary neutron dose may not exceed one in a thousand of the carbon ions dose at Bragg peak area in tissue-like media.

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

2015-03-18

232

Hepatocellular Carcinoma Radiation Therapy: Review of Evidence and Future Opportunities  

SciTech Connect

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

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

2013-09-01

233

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

Cancer.gov

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

234

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

235

[The application of total quality management (TQM) in quality management of radiation therapy].  

PubMed

The strategies and methods of the total quality management (TQM) need to applied in quality management of radiation therapy. We should improve the level of quality control and quality assurance in radiation therapy. By establishing quality control system in radiation therapy, standardization of radiation therapy workflow, strengthening quality control of devices and physical technique and paying attention to safety protection and staff training. PMID:19565799

Jiang, Rui-yao; Fu, Shen; Li, Bin

2009-03-01

236

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

PubMed

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

Purdy, James A

2008-11-01

237

Optimization of radiation therapy treatment planning  

SciTech Connect

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

Ezzell, G.

1994-12-31

238

21 CFR 892.5900 - X-ray radiation therapy system.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

239

21 CFR 892.5900 - X-ray radiation therapy system.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

240

21 CFR 892.5900 - X-ray radiation therapy system.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

241

21 CFR 892.5900 - X-ray radiation therapy system.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

242

21 CFR 892.5900 - X-ray radiation therapy system.  

Code of Federal Regulations, 2014 CFR

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

2014-04-01

243

Stereotactic Body Radiation Therapy in Spinal Metastases  

SciTech Connect

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

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

2012-04-01

244

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

SciTech Connect

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

Montes, J.G.

1983-01-01

245

Hemorrhage into cystic vestibular schwannoma following stereotactic radiation therapy.  

PubMed

The occurrence of a hemorrhage into a vestibular schwannoma is a rare phenomenon. Several reports, however, indicate a risk profile for a subgroup of patients with vestibular schwannoma which show hypervascularity in the histopathological examination. Cystic formation, large size, mixed Antoni type and anticoagulation therapy seem to enhance the risk of tumor hemorrhage. We report on a patient with a large cystic vestibular schwannoma who died from fatal bleeding into the tumor 15 months following stereotactic radiation therapy. Since hemorrhage seems to be a relevant risk in large cystic vestibular schwannomas, a surgical treatment should be preferred whenever possible. PMID:18666062

Ganslandt, O; Fahrig, A; Strauss, C

2008-11-01

246

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

PubMed Central

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

2013-01-01

247

RADIATION THERAPY IN DISEASES OF THE EYE  

PubMed Central

Because of the wide variety of x-rays now available, selectivity is possible and important in treatment of diseases of the eye. By the use of short-range radiation, newly developed eye shields and the insulation of the eyelid itself, and by careful angulation of the beam, the desired irradiation can be given where it is needed without injury to surrounding tissues. The authors have found the 50 kv x-ray unit to be the most reliable and adaptable for most circumstances. The skin of the eyelid reacts to irradiation more sensitively than other tissues. The cornea reacts with keratitis and sometimes intractable ulceration. The iris, uveal tract and retina are less seriously affected. At the University of California Hospital irradiation has been found satisfactory for treatment of corneal ulcer, keratitis, pterygium, certain types of conjunctivitis, episcleritis, corneal vascularization, iritis, uveitis, and hemangioma. Irradiation may be of great benefit in absolute glaucoma with pain and blindness. Of 42 patients with carcinoma of the eyelid treated between 1935 and 1946, 27 had no recurrence in five years, 5 had recurrence, 7 died of other causes and follow-up was incomplete on 3. Good cosmetic result was usually achieved. No recurrence has been observed in 22 patients treated since 1946. Irradiation has been used with success in other kinds of cancer of the eye structures. PMID:13126810

Sherman, Robert S.; Hogan, Michael J.

1954-01-01

248

Gold nanoparticles and their alternatives for radiation therapy enhancement.  

PubMed

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

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

2014-01-01

249

Neurovisual outcome following proton radiation therapy.  

PubMed

From February 1981 to January 1984, 20 patients with a tumor of the upper clivus received proton irradiation at the Harvard Cyclotron Laboratory. For 15 patients with known neurovisual status (including visual acuity, color vision, visual field, and fundus examinations) we obtained a cumulative dose-volume histogram (DVH) of the optic nerves (ON) and the optic chiasm. The prescribed tumor doses ranged from 66.6 to 74.4 Cobalt Gray Equivalent (CGE) with a daily fraction size of 1.8 to 2.1 CGE. CGE is used because modulated protons have an RBE of 1.1 compared to 60Co. The follow-up ranged from 30 to 68 months (median 52). Two patients developed, 10 and 36 months post irradiation, a progressive visual deterioration affecting both eyes. This was attributed to an ON and a chiasm injury in one patient and to bilateral ON injury in the other patient. In the first patient, the dose-volume analysis indicated that approximately half of the ON and of the chiasm had received 65 CGE and 55 CGE, respectively. In the second patient, it indicated that a quarter of the left ON (LON) had received 55 CGE whereas the dose to the right ON (RON) was significantly less. This patient had diabetes mellitus which may be a predisposing factor. From this study, a complication rate of 20% (1/5) is observed when a substantial portion of the ON is taken to 65 CGE, while it doesn't exceed 12.5% (2/16) and 7.5% (1/13) at 55 CGE for the ON and for the chiasm, respectively. This suggests a tolerance dose implying a 10% rate of major complications close to 55 CGE. When a tumor requires a high radiation-dose, the exclusion of these structures at 55 to 60 Gy is recommended. PMID:2542198

Habrand, I L; Austin-Seymour, M; Birnbaum, S; Wray, S; Carroll, R; Munzenrider, J; Verhey, L; Urie, M; Goitein, M

1989-06-01

250

Radiation therapy for advanced gastric cancer  

SciTech Connect

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

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

1988-07-01

251

[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

252

Innovative technologies in thoracic radiation therapy for lung cancer  

PubMed Central

Radiation therapy plays a major role in the cure of patients affected with lung cancer, both in early and locally advanced disease. Local control and survival rates are still poor, even with the best combination with chemotherapy and/or targeted agents. The recent technical advances in radiotherapy changed the planning and delivery processes, enabling radiation oncologists to modify treatment schedules towards further dose intensification, while opening a new scenario for future clinical studies. In this paper we briefly review the major technical changes in the field of thoracic radiotherapy for primary lung tumors and their potential in improving clinical outcomes.

Mantovani, Cristina; Ricardi, Umberto

2012-01-01

253

Shielding and Radiation Protection in Ion Beam Therapy Facilities  

NASA Astrophysics Data System (ADS)

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

Wroe, Andrew J.; Rightnar, Steven

254

Adaptive and robust radiation therapy in the presence of drift.  

PubMed

Combining adaptive and robust optimization in radiation therapy has the potential to mitigate the negative effects of both intrafraction and interfraction uncertainty over a fractionated treatment course. A previously developed adaptive and robust radiation therapy (ARRT) method for lung cancer was demonstrated to be effective when the sequence of breathing patterns was well-behaved. In this paper, we examine the applicability of the ARRT method to less well-behaved breathing patterns. We develop a novel method to generate sequences of probability mass functions that represent different types of drift in the underlying breathing pattern. Computational results derived from applying the ARRT method to these sequences demonstrate that the ARRT method is effective for a much broader class of breathing patterns than previously demonstrated. PMID:25860509

Mar, Philip Allen; Chan, Timothy C Y

2015-05-01

255

Impact of dose calculation algorithm on radiation therapy  

PubMed Central

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

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

2014-01-01

256

Impact of dose calculation algorithm on radiation therapy.  

PubMed

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

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

2014-11-28

257

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

258

Sigmoid Perforation Following Radiation Therapy in Patients with Cervical Cancer  

Microsoft Academic Search

Objective. We describe the clinical presentation, evaluation, management, and outcome of patients experiencing sigmoid perforation following radiation therapy for cervical cancer.Methods. A database consisting of over 5000 patients with stage IB–IIIB cervix cancer treated between 1963 and 1992 revealed 35 patients with sigmoid perforation. Twenty-seven were diagnosed and managed at one institution, and they form the study group.Results. The median

Pedro T. Ramirez; Charles Levenback; Thomas W. Burke; Patricia Eifel; Judith K. Wolf; David M. Gershenson

2001-01-01

259

A collaboratory for radiation therapy treatment planning optimization research  

Microsoft Academic Search

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

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

2006-01-01

260

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

261

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

262

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

263

NOTE: Uniaxial and biaxial irradiation protocols for microbeam radiation therapy  

NASA Astrophysics Data System (ADS)

Synchrotron-generated x-ray beams for microbeam radiation therapy (MRT) are fixed in space, so three-dimensional treatment planning would require that a patient be secured to, and moved in a gantry between exposures. Two protocols for such movements are proposed: one for uniaxial opposing-fields cross-planar MRT, the other for biaxial orthogonal-fields co-planar MRT.

Slatkin, Daniel N.

2004-07-01

264

Fibrosarcoma after high energy radiation therapy for pituitary adenoma  

SciTech Connect

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

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

1980-11-01

265

A mathematical model for brain tumor response to radiation therapy  

PubMed Central

Gliomas are highly invasive primary brain tumors, accounting for nearly 50% of all brain tumors (Alvord and Shaw in The pathology of the aging human nervous system. Lea & Febiger, Philadelphia, pp 210–281, 1991). Their aggressive growth leads to short life expectancies, as well as a fairly algorithmic approach to treatment: diagnostic magnetic resonance image (MRI) followed by biopsy or surgical resection with accompanying second MRI, external beam radiation therapy concurrent with and followed by chemotherapy, with MRIs conducted at various times during treatment as prescribed by the physician. Swanson et al. (Harpold et al. in J Neuropathol Exp Neurol 66:1–9, 2007) have shown that the defining and essential characteristics of gliomas in terms of net rates of proliferation (?) and invasion (D) can be determined from serial MRIs of individual patients. We present an extension to Swanson’s reaction-diffusion model to include the effects of radiation therapy using the classic linear-quadratic radiobiological model (Hall in Radiobiology for the radiologist. Lippincott, Philadelphia, pp 478–480, 1994) for radiation efficacy, along with an investigation of response to various therapy schedules and dose distributions on a virtual tumor (Swanson et al. in AACR annual meeting, Los Angeles, 2007). PMID:18815786

Rockne, R.; Alvord, E. C.; Rockhill, J. K.

2013-01-01

266

Analytical probabilistic modeling for radiation therapy treatment planning.  

PubMed

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

Bangert, Mark; Hennig, Philipp; Oelfke, Uwe

2013-08-21

267

Analytical probabilistic modeling for radiation therapy treatment planning  

NASA Astrophysics Data System (ADS)

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

Bangert, Mark; Hennig, Philipp; Oelfke, Uwe

2013-08-01

268

Medical factors influencing decision making regarding radiation therapy for breast cancer  

PubMed Central

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

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

2014-01-01

269

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

PubMed Central

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

Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham

2013-01-01

270

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

271

Androgen Deprivation Therapy Toxicity and Management for Men Receiving Radiation Therapy  

PubMed Central

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

Johnson, Matthew E.; Buyyounouski, Mark K.

2012-01-01

272

Fifty years of progress in radiation therapy for breast cancer.  

PubMed

Fifty years ago, radiation therapy (RT) was only used after mastectomy in patients with high-risk disease. The equipment, treatment planning, and treatment delivery were rudimentary compared to what is available today. In retrospect, the deleterious effects of the RT back then negated its benefits. The strategy of combining lesser surgery with RT (and adjuvant systemic therapy) has been successfully employed in breast-conserving therapy (BCT) and in avoiding axillary lymph node dissection in patients with 1 or 2 involved sentinel nodes. Local recurrence rates at 10 years following BCT are now similar to those following mastectomy. RT after breast-conserving surgery and after mastectomy has been demonstrated to not only decrease local-regional recurrence but also decrease distant metastases and improve long-term survival. The development of effective adjuvant systemic therapy has made RT not only more effective but also arguably more important. If systemic therapy is effective at addressing micro-metastatic disease, then obtaining local tumor control becomes even more important. Moderately hypofractionated RT (2.66 Gy per day) is just as safe and effective as conventional fractionation shortening BCT from 6 weeks to 3-4 weeks. Treatment is now given with multiple-energy linear accelerators, CT-based simulation, 3-dimensional beam modulation for much greater dose homogeneity, on-board imaging for greater daily accuracy, and various techniques to reduce cardiac dose. PMID:24857056

Harris, Jay R

2014-01-01

273

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

PubMed Central

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

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

2012-01-01

274

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

PubMed

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

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

2013-01-01

275

Optimal approach in early breast cancer: Radiation therapy  

PubMed Central

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

Poortmans, Philip

2013-01-01

276

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

SciTech Connect

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

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

2013-08-01

277

Intensity-modulated radiation therapy for prostate cancer.  

PubMed

Intensity-modulated radiation therapy (IMRT) represents a new paradigm in radiation treatment planning and delivery for treatment of prostate cancer with enormous potential. Preliminary data indicate that this highly conformal treatment technique can effectively reduce acute and late-occurring toxicities, improving the quality of life of the treated patient and serving as the optimal dose escalation tool. IMRT produces radiation distributions capable of delivering different dose prescriptions to multiple target sites, providing a new opportunity for differential dose painting to increase the dose selectively to specific, image-defined regions within the prostate. Clinical trials will be necessary to define more clearly the true extent of improved tumor control and reduction in normal tissue complications with IMRT in the treatment of prostate cancer. PMID:12118388

Zelefsky, Michael J; Fuks, Zvi; Leibel, Steven A

2002-07-01

278

Intensity modulating and other radiation therapy devices for dose painting.  

PubMed

The introduction of intensity-modulated radiation therapy (IMRT) in the early 1990s created the possibility of generating dramatically improved dose distributions that could be tailored to fit a complex geometric arrangement of targets that push against or even surround healthy critical structures. IMRT is a new treatment paradigm that goes beyond the capabilities of the earlier technology called three-dimensional radiation therapy (3DCRT). IMRT took the older approach of using fields that conformed to the silhouette of the target to deliver a relatively homogeneous intensity of radiation and separated the conformal fields into many subfields so that intensity could be varied to better control the final dose distribution. This technique makes it possible to generate radiation dose clouds that have indentations in their surface. Initially, this technology was mainly used to avoid and thus control the dose delivered to critical structures so that they are not seriously damaged in the process of irradiating nearby targets to an appropriately high dose. Avoidance of critical structures allowed homogeneous dose escalation that led to improved local control for small tumors. However, the normal tissue component of large tumors often prohibits homogeneous dose escalation. A newer concept of dose-painting IMRT is aimed at exploiting inhomogeneous dose distributions adapted to tumor heterogeneity. Tumor regions of increased radiation resistance receive escalated dose levels, whereas radiation-sensitive regions receive conventional or even de-escalated dose levels. Dose painting relies on biologic imaging such as positron emission tomography, functional magnetic resonance imaging, and magnetic resonance spectroscopy. This review will describe the competing techologies for dose painting with an emphasis on their commonalities. PMID:17350940

Galvin, James M; De Neve, Wilfried

2007-03-10

279

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

280

Pioneer F Plaque Location  

NASA Technical Reports Server (NTRS)

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

1972-01-01

281

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

SciTech Connect

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

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

2012-11-15

282

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. PMID:23450865

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

2012-01-01

283

Overview of Radiation Therapy for Treating Rectal Cancer  

PubMed Central

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

Kye, Bong-Hyeon

2014-01-01

284

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

SciTech Connect

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

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

2013-01-01

285

Accuracy of Marketing Claims by Providers of Stereotactic Radiation Therapy  

PubMed Central

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

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

2013-01-01

286

Third generation gold nanoplatform optimized for radiation therapy  

PubMed Central

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

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

2013-01-01

287

Regorafenib-induced transverse myelopathy after stereotactic body radiation therapy  

PubMed Central

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

Tian, Sibo; Nissenblatt, Michael

2014-01-01

288

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

289

Strategies for quality assurance of intensity modulated radiation therapy  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

290

Late effects of radiation therapy on the gastrointestinal tract  

SciTech Connect

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

Coia, L.R. [Fox Chase Cancer Center, Philadelphia, PA (United States)] [Fox Chase Cancer Center, Philadelphia, PA (United States); Myerson, R.J. [Washington Univ. Medical Center, St. Louis, MO (United States)] [Washington Univ. Medical Center, St. Louis, MO (United States); Tepper, J.E. [North Carolina School of Medicine, Chapel Hill, NC (United States)] [North Carolina School of Medicine, Chapel Hill, NC (United States)

1995-03-30

291

On coupled Boltzmann transport equation related to radiation therapy  

NASA Astrophysics Data System (ADS)

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

Tervo, J.

2007-11-01

292

Proton radiation therapy: A summary of the world wide experience  

NASA Astrophysics Data System (ADS)

There are 16 operating proton therapy centers world-wide in 1994. By July 1994, proton beams had been used to treat ˜ 14000 patients for both benign and malignant disease. Six centers are located in Europe, four in the United States, three in Russia, two in Japan and one in South Africa. Accelerators originally designed for other purposes and adapted for radiation therapy are employed at all but one center which has an accelerator designed and built for the hospital environment. At six centers the accelerator has a maximum energy of < 100 MeV; only a limited number of sites can be treated. Proton beams of variable energy are available at six centers, otherwise additional material is placed in the beam line to degrade the energy. Passive scattering techniques are used to spread the beam in the lateral dimension. Ridge filters or rotating propellers of various materials are used to modulate the beam with depth.

Sisterson, Janet M.

1995-05-01

293

Intensity-modulated radiation therapy for pediatric medulloblastoma: early report on the reduction of ototoxicity  

Microsoft Academic Search

Purpose: The combination of cisplatin chemotherapy and radiation therapy for the treatment of medulloblastoma has been shown to cause significant ototoxicity, impairing a child’s cognitive function and quality of life. Our purpose is to determine whether the new conformal technique of intensity-modulated radiation therapy (IMRT) can achieve lower rates of hearing loss by decreasing the radiation dose delivered to the

Eugene Huang; Bin S Teh; Douglas R Strother; Quillin G Davis; J. Kam Chiu; Hsin H Lu; L. Steven Carpenter; Wei-Yuan Mai; Murali M Chintagumpala; Michael South; Walter H Grant III; E. Brian Butler; Shiao Y Woo

2002-01-01

294

Radiation therapy quality control in a clinical trial of adjuvant postoperative treatment for rectal cancer  

Microsoft Academic Search

Purpose: Deviations from protocol can detract from the reliability of results obtained in prospective clinical trials. In an effort to decrease the number of deviations in a prospective trial of adjuvant treatment for rectal cancer, we undertook pretreatment review of the irradiated fields.Methods and Materials: Before initiation of radiation therapy, patients' radiation therapy fields were simulated by their radiation oncologists

James A. Martenson; Rodolfo Urias; Stephen R. Smalley; Lawrence R. Coia; Joel E. Tepper; Marvin Rotman; Tyvin A. Rich; Michael J. O'Connell

1995-01-01

295

A Method for Evaluating Quality Assurance Needs in Radiation Therapy  

SciTech Connect

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

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

2008-05-01

296

Change in Seroma Volume During Whole-Breast Radiation Therapy  

SciTech Connect

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

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

2009-09-01

297

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

298

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

Code of Federal Regulations, 2013 CFR

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

2013-10-01

299

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

Code of Federal Regulations, 2010 CFR

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

2010-10-01

300

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

Code of Federal Regulations, 2014 CFR

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

2014-10-01

301

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

302

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

303

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.

304

[Radiation-induced and therapy-related AML/MDS].  

PubMed

Radiation induced acute myeloid leukemia (AML) was recognized a century ago, soon after mankind found radiation. Atomic bomb survivors developed de novo AML with relatively short latency with very high frequency. By contrast, excess occurrence of myelodysplastic syndrome (MDS) as well as solid tumors was found decades late. This difference may be due to etiology that many de novo AML patients harbor chimeric leukemogenic genes caused by chromosomal translocations, while MDS patients rarely carry chimeras. In addition, epigenetic change would play important roles. Therapy related leukemia is mainly caused by topoisomerase II inhibitors that cause de novo AML with an 11q23 translocation or by alkyrating agents that induce MDS/AML with an AML1 point mutation and monosomy 7. PMID:19860183

Inaba, Toshiya

2009-10-01

305

Technical aspects of radiation therapy for anal cancer  

PubMed Central

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

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

2014-01-01

306

Monte Carlo dose enhancement studies in microbeam radiation therapy  

SciTech Connect

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

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

2011-07-15

307

Fast Monte Carlo for radiation therapy: the PEREGRINE Project  

SciTech Connect

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

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

1997-11-11

308

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

309

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

SciTech Connect

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

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

1994-09-01

310

Dental plaque formation  

Microsoft Academic Search

Dental plaque is a complex biofilm that accumulates on the hard tissues (teeth) in the oral cavity. Although over 500 bacterial species comprise plaque, colonization follows a regimented pattern with adhesion of initial colonizers to the enamel salivary pellicle followed by secondary colonization through interbacterial adhesion. A variety of adhesins and molecular interactions underlie these adhesive interactions and contribute to

Burton Rosan; Richard J Lamont

2000-01-01

311

Atherosclerotic carotid plaque segmentation  

Microsoft Academic Search

Atherosclerosis is the major cause of heart attack and stroke in the western world. In this paper we present a computerized method for segmenting the athrerosclerotic carotid plaque from ultrasound images. The method uses the blood flow image first to detect the initial contour of the plaque, and then despeckle filtering and snakes to deform the initial contour for best

C. P. Loizou; C. S. Pattichis; R. S. H. Istepanian; M. Pantziaris; A. Nicolaides

2004-01-01

312

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

313

Subacute brain atrophy after radiation therapy for malignant brain tumor  

SciTech Connect

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

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

1989-05-15

314

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

315

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

316

Interference detection in implantable defibrillators induced by therapeutic radiation therapy  

PubMed Central

Background Electromagnetic fields and ionising radiation during radiotherapy can influence the functioning of ICDs. Guidelines for radiotherapy treatment were published in 1994, but only based on experience with pacemakers. Data on the influence of radiotherapy on ICDs is limited. Objectives We determined the risk to ICDs of interference detection induced by radiotherapy. Methods In our study we irradiated 11 ICDs. The irradiation was performed with a 6 megavolt photon beam. In each individual device test, a total of 20 Gray was delivered in a fractionated fashion. During each irradiation the output stimulation rate was monitored and electrogram storage was activated. In case of interference the test was repeated with the ICD outside and the lead(s) inside and outside the irradiation field. Results With the ICD inside the irradiation field, interference detection was observed in all ICDs. This caused pacing inhibition or rapid ventricular pacing. Ventricular tachycardia (VT) or ventricular fibrillation (VF) detection occurred, which would have caused tachycardia-terminating therapy. If the ICD was placed outside the irradiation field, no interference was observed. Conclusion Interference by ionising radiation on the ICDs is demonstrated both on bradycardia and tachycardia therapy. This can have consequences for patients. Recommendations for radiotherapy are presented in this article. ImagesFigure 1Figure 5 PMID:25696559

Uiterwaal, G.J.; Springorum, B.G.F.; Scheepers, E.; de Ruiter, G.S.; Hurkmans, C.W.

2006-01-01

317

Intraluminal radiation therapy in the management of malignant biliary obstruction  

SciTech Connect

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

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

1986-02-01

318

Salvage radiation therapy and chemoradiation therapy for postoperative locoregional recurrence of esophageal cancer.  

PubMed

The purpose of this retrospective study was to assess the efficacy of salvage radiation therapy (RT) or chemoradiation therapy (CRT) for locoregional recurrence (LR) of esophageal cancer after curative surgery. Forty-two patients who received salvage RT or CRT for LR of esophageal cancer after curative surgery between November 2000 and May 2012 were reviewed. The intended RT regimen was 60?Gy in 30 fractions combined with concurrent platinum-based chemotherapy. Median follow-up periods were 17.9 months for all evaluable patients and 28.2 months for patients still alive (19 patients) at analysis time. The 1-, 2-, and 3-year survival rates were 81.2 ± 6.4%, 51.3 ± 8.6%, and 41.1 ± 8.7%, respectively, with a median survival time of 24.3 ± 4.1 months. Out of 41 evaluable patients, 16 patients (39%) were alive beyond 2 years from salvage therapy. However, univariate analyses for overall survival showed no significant prognostic factor. Grade 3 or higher leukocytopenia was observed in 46% of the patients. Salvage RT or CRT for LR after surgery for esophageal cancer was safe and effective. These therapies may offer long-term survival to some patients. RT or CRT should be considered for LR. PMID:23551708

Kobayashi, R; Yamashita, H; Okuma, K; Shiraishi, K; Ohtomo, K; Nakagawa, K

2014-01-01

319

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

320

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

PubMed Central

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

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

2011-01-01

321

Primary radiation therapy for locally advanced breast cancer.  

PubMed

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%. It is concluded that high-dose radiation therapy without mastectomy is an effective means of controlling local-regional tumor in patients with locally advanced breast cancer. PMID:3621108

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

322

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

SciTech Connect

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

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

2010-01-01

323

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

ClinicalTrials.gov

Bladder Cancer; Cervical Cancer; Colorectal Cancer; Endometrial Cancer; Gastrointestinal Complications; Long-term Effects Secondary to Cancer Therapy in Adults; Ovarian Cancer; Prostate Cancer; Radiation Toxicity; Sarcoma; Testicular Germ Cell Tumor; Vaginal Cancer

2011-07-14

324

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

SciTech Connect

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

Muller-Runkel, R.; Orsolini, G.; Kalokhe, U.P. (Saint Margaret Hospital and Health Centers, Hammond, IN (USA))

1990-11-01

325

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

MedlinePLUS

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

326

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

327

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

Microsoft Academic Search

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

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

1997-01-01

328

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

PubMed Central

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

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

2014-01-01

329

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

330

Radiation Therapy Using High-Energy Carbon Beams  

NASA Astrophysics Data System (ADS)

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

Kanai, T.

331

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

NASA Technical Reports Server (NTRS)

Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low-dose-rate dose to the bone marrow (mean = 2.5 Gy) was consistent with the measured ERR (0.62, 95% Cl =-0.2 to 1.9). Conclusions: An extended, biologically based model for leukemia that includes HSC initiation, inactivation, proliferation, and, uniquely for leukemia, long-range HSC migration predicts, %Kith reasonable accuracy, risks for radiationinduced leukemia associated with exposure to therapeutic doses of radiation.

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

2006-01-01

332

Effects of radiation therapy on skeletal growth in childhood  

SciTech Connect

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

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

1991-01-01

333

Radiation Therapy Oncology Group clinical trials with misonidazole  

SciTech Connect

This paper presents a review of the progressive clinical trials of the hypoxic cell radiosensitizer, misonidazole, in the Radiation Therapy Oncology Group (RTOG). Presentation is made of all the schemas of the recently completed and currently active RTOG Phase II and Phase III studies. Detailed information is provided on the clinical toxicity of the Phase II trials, specifically regarding neurotoxicity. With limitations in drug total dose, a variety of dose schedules have proven to be tolerable, with a moderate incidence of nausea and vomiting and mild peripheral neuropathy or central neuropathy. No other organ toxicity has been seen, specifically no liver, renal or bone marrow toxicities. An additional Phase III malignant glioma trial in the Brain Tumor Study Group is described.

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

1981-05-15

334

Treatment of locally advanced prostate cancer with radiation therapy.  

PubMed

External beam radiation has been the most common curative treatment for the patient with Stage C prostate cancer, with ten-year survivals of 38-40 percent and ten-year free-from-recurrence rates of 28 percent and 30 percent. A number of problems are apparent, including the need to confirm positive imaging studies by biopsy, the need to avoid the apparent adverse effects of transurethral resection of the prostate (TURP) in a subset of Stage C patients, the need to complete ongoing prospective trials of adjuvant androgen deprivation, and the need to complete trials of neutron therapy and implants designed to improve local control. Patients with Stage C cancer should be encouraged by their physicians to enter prospective trials addressing these pertinent questions. PMID:2496516

Hanks, G E

1989-05-01

335

Low Level Laser Therapy: laser radiation absorption in biological tissues  

NASA Astrophysics Data System (ADS)

In this paper we report the results of an experimental study in which we have measured the transmitted laser radiation through dead biological tissues of various animals (chicken, adult and young bovine, pig) in order to evaluate the maximum thickness through which the power density could still produce a reparative cellular effect. In our experiments we have utilized a pulsed laser IRL1 ISO model (based on an infrared diode GaAs, ?=904 nm) produced by BIOMEDICA s.r.l. commonly used in Low Level Laser Therapy. Some of the laser characteristics have been accurately studied and reported in this paper. The transmission results suggest that even with tissue thicknesses of several centimeters the power density is still sufficient to produce a cell reparative effect.

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

2013-07-01

336

Treatment of early stage thymic tumors: surgery and radiation therapy.  

PubMed

Tumors of the thymus are an uncommon entity, constituting 30% and 15% of anterior mediastinal masses in adults and children, respectively. The majority of these tumors are thymomas, with thymic carcinomas less common, and thymic carcinoids exceedingly rare. Recognition of the distinct clinicopathologic behavior of various thymic neoplasms is crucial to providing optimal treatment. Evidence guiding the treatment of early stage thymic tumors is limited secondary to the low incidence and resulting lack of randomized data. Proper management requires a careful analysis of the available literature with particular attention paid to limitations of the existing studies. This article provides a discussion of the presentation, evaluation, diagnosis, surgical techniques, and treatment outcomes relevant to early stage thymomas, thymic carcinomas, and thymic carcinoid tumors. The role of radiation therapy in the management of early stage thymic tumors remains controversial and is discussed in detail. PMID:19169830

Gielda, Benjamin T; Peng, Rick; Coleman, Joy L; Thomas, Charles R; Cameron, Robert B

2008-12-01

337

Primary pericardial malignant mesothelioma and response to radiation therapy  

PubMed Central

We report a case of a primary pericardial malignant mesothelioma. A 59-year-old male presented with episodic chest pain and dyspnea on exertion. Cardiac magnetic resonance imaging revealed a large mass in the pericardium attached to the right ventricle. Partial resection of the mass was undertaken revealing malignant mesothelioma, byphasic type. The patient was treated with chemotherapy intermittently over a period of 3 years, but his disease continued to progress. The patient was then treated with definitive radiation therapy to 64 Gy to the primary tumor using a six field 3D conformal technique. The patient remains free of progressive disease 86 months from the time of diagnosis and 50 months from the completion of his radiotherapy. PMID:21139966

Reardon, Kelli A; Reardon, Michael A; Moskaluk, Christopher A; Grosh, William W; Read, Paul W

2010-01-01

338

The verification of an inverse problem in radiation therapy.  

PubMed

The inverse problem in radiation therapy presents a solution for a fluence distribution based on the specification of a region of dose in a patient. We show results for one such solution based on the inversion of an integral over a function of the fluence profile of a rotating beam. We use Monte Carlo methods and numerical integrations to evaluate dose distributions obtained with the inverse method and show the limitations of this theoretical approach. Our results show that dose to a single circular region at an arbitrary position in a 2-dimensional volume can be calculated. Uniform dose to arbitrarily shaped regions cannot be calculated with this formalism, although practical solutions can still be obtained. PMID:2303370

Kooy, H M; Barth, N H

1990-02-01

339

Improved treatment planning for COMS eye plaques  

SciTech Connect

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

Astrahan, Melvin A. [Department of Radiation Oncology, University of Southern California Norris Cancer Hospital, Los Angeles, CA (United States)]. E-mail: astrahan@usc.edu

2005-03-15

340

Calcified basal ganglionic mass 12 years after radiation therapy for medulloblastoma  

SciTech Connect

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

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

1984-04-01

341

The use of intraoperative radiation therapy in radical salvage for recurrent cervical cancer: Outcome and toxicity  

Microsoft Academic Search

Objective: Our purpose was to evaluate the contribution of intraoperative radiation therapy in the management of recurrent cervical cancer.Study design: Twenty-two patients were treated with electron beam intraoperative radiation therapy for recurrent cervical cancers that were confined to the pelvis but were too extensive to be adequately treated by radical surgery alone. All patients underwent extensive surgical dissection for exposure

Keith J. Stelzer; Wui-Jin Koh; Benjamin E. Greer; Joanna M. Cain; Hisham K. Tamimi; David C. Figge; Barbara A. Goff; Thomas W. Griffin

1995-01-01

342

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

E-print Network

) plays an important role in the treatment of patients with lung cancer. The goal of radiation therapy is to eradicate cancer cells while sparing normal tissues. The objective of RT treatment planning (RTTPEvaluating geometrical accuracy of image registration methods in SPECT guided radiation therapy

Hamarneh, Ghassan

343

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

344

Stereotactic body radiation therapy for centrally-located lung tumors  

PubMed Central

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

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

2014-01-01

345

Automated fiducial marker planning for thoracic stereotactic body radiation therapy  

NASA Astrophysics Data System (ADS)

Stereotactic body-radiation therapy (SBRT) has gained acceptance in treating lung cancer. Localization of a thoracic lesion is challenging as tumors can move significantly with breathing. Some SBRT systems compensate for tumor motion with the intrafraction tracking of targets by two stereo fluoroscopy cameras. However, many lung tumors lack a fluoroscopic signature and cannot be directly tracked. Small radiopaque fiducial markers, acting as fluoroscopically visible surrogates, are instead implanted nearby. The spacing and configuration of the fiducial markers is important to the success of the therapy as SBRT systems impose constraints on the geometry of a fiducial-marker constellation. It is difficult even for experienced physicians mentally assess the validity of a constellation a priori. To address this challenge, we present the first automated planning system for bronchoscopic fiducial-marker placement. Fiducial-marker planning is posed as a constrained combinatoric optimization problem. Constraints include requiring access from a navigable airway, having sufficient separation in the fluoroscopic imaging planes to resolve each individual marker, and avoidance of major blood vessels. Automated fiducial-marker planning takes approximately fifteen seconds, fitting within the clinical workflow. The resulting locations are integrated into a virtual bronchoscopic planning system, which provides guidance to each location during the implantation procedure. To date, we have retrospectively planned over 50 targets for treatment, and have implanted markers according to the automated plan in one patient who then underwent SBRT treatment. To our knowledge, this approach is the first to address automated bronchoscopic fiducialmarker planning for SBRT.

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

2012-02-01

346

On bolus for megavoltage photon and electron radiation therapy  

SciTech Connect

Frequently, in radiation therapy one must treat superficial lesions on cancer patients; these are at or adjacent to the skin. Megavoltage photon radiotherapy penetrates through the skin to irradiate deep-seated tumors, with skin-sparing property. Hence, to treat superficial lesions, one must use a layer of scattering material to feign as the skin surface. Although megavoltage electron beams are used for superficial treatments, one occasionally needs to enhance the dose near the surface. Such is the function of a “bolus,” a natural or synthetically developed material that acts as a layer of tissue to provide a more effective treatment to the superficial lesions. Other uses of boluses are to correct for varying surface contours and to add scattering material around the patient's surface. Materials used as bolus vary from simple water to metal and include various mixtures and compounds. Even with the modernization of the technology for external-beam therapy and the emergence of various commercial boluses, the preparation and utilization of a bolus in clinical radiotherapy remains an art. Considering the varying experiences and practices, this paper briefly summarizes available boluses that have been proposed and are employed in clinical radiotherapy. Although this review is not exhaustive, it provides some initial guidance and answers questions that may arise in clinical practice.

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

2013-10-01

347

Automatic CT simulation optimization for radiation therapy: A general strategy  

SciTech Connect

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

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

2014-03-15

348

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

349

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

350

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

351

A case of spontaneous pneumothorax following radiation therapy for non-small cell lung cancer  

PubMed Central

Spontaneous pneumothorax (SPTX) is a potentially devastating rare complication of the thoracic radiation therapy. Most of the cases in the medical literature, have been described in lymphoma patients receiving radiation therapy. The pathogenesis of this adverse event remains undefined although different mechanisms have been proposed. We present a case of post-radiation therapy SPTX in a non-small cell lung cancer (NSCLC), following intensity modulated radiation therapy (IMRT), which to our knowledge is the first such reported case related to this newer mode of radiation therapy. This report highlights the importance of keeping a close eye for this complication as timely treatment with chest tube insertion and drainage of the pneumothorax can be a lifesaving in these patients. PMID:24339501

Bhardwaj, Himanshu; Bhardwaj, Bhaskar; Youness, Houssein A.

2013-01-01

352

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. PMID:19707434

Gall, Jennifer S; Kalb, Robert E

2008-01-01

353

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

Cancer.gov

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

354

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

Cancer.gov

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

355

Expression of NPP1 is regulated during atheromatous plaque calcification  

PubMed Central

Abstract Mutations of the ENPP1 gene encoding ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1) are associated with medial calcification in infancy. While the inhibitory role of matrix proteins such as osteopontin (OPN) with respect to atherosclerotic plaque calcification has been established, the role of NPP1 in plaque calcification is not known. We assessed the degree of plaque calcification (computed tomography), NPP1 and OPN localization (immunohistochemistry) and expression (RT-PCR) in a cohort of 45 patients undergoing carotid endatherectomy for significant stenosis of the internal carotid artery and in normal arteries (N= 50). We correlated NPP1 and OPN expression levels to the degree of plaque calcification, to pro-atherogenic factors and statin therapy. NPP1 was demonstrated in the base and in the shoulder of atherosclerotic plaques. Compared to normal arteries and non-calcified plaques, in calcified plaques NPP1 mRNA was decreased (P < 0.0001). OPN mRNA levels were up-regulated in carotid atheroma. NPP1 and OPN expression levels positively correlated with the degree of plaque calcification (R= 0.54, P= 0.00019 and R= 0.46, P= 0.017, respectively) and with risk factors of atherosclerosis. Expression of the calcification inhibitor NPP1 is down-regulated in calcified atherosclerotic plaques. Our correlation data point to a counter-active mechanism, which in the end turns out to be insufficient to prevent further progression of calcification. PMID:20015201

Nitschke, Yvonne; Hartmann, Simone; Torsello, Giovanni; Horstmann, Rüdiger; Seifarth, Harald; Weissen-Plenz, Gabriele; Rutsch, Frank

2011-01-01

356

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

PubMed Central

In radiation therapy with high-energy photon beams (E > 10 MeV) neutrons are generated mainly in linacs head thorough (?,n) interactions of photons with nuclei of high atomic number materials that constitute the linac head and the beam collimation system. These neutrons affect the shielding requirements in radiation therapy rooms and also increase the out-of-field radiation dose of patients undergoing radiation therapy with high-energy photon beams. In the current review, the authors describe the factors influencing the neutron production for different medical linacs based on the performed measurements and Monte Carlo studies in the literature. PMID:24376940

Naseri, Alireza; Mesbahi, Asghar

2010-01-01

357

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

PubMed

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

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

2014-04-01

358

Survival of patients treated with radiation therapy for anaplastic astrocytoma  

PubMed Central

Background Anaplastic astrocytoma (AA) represents 7% of primary brain tumors in adults. Patient-, tumor-, and treatment-related factors are thought to be predictive of survival. We retrospectively assessed the association of patient-, tumor-, and treatment-related factors with survival in AA treated with radiotherapy (RT) at our institution. Patients and methods. Medical records of patients with AA treated with RT between 1987 and 2007 were reviewed. Patient-, tumor-, and treatment-related variables were recorded and used to assign patients to a Radiation Therapy Oncology Group recursive partitioning analysis (RTOG RPA) classification. First use of chemotherapy was recorded. Log-rank tests and Cox regression models were used to assess for an association of patient-, tumor- and treatment-related factors with survival. Results One-hundred twenty-six patients were eligible for study. Median age, Karnofsky performance status, and duration of symptoms were 43 years, 90, and 8 weeks. Median radiation dose was 59.4 Gy; 61% of patients underwent tumor resection, and 17% and 41% of patients received temozolomide during and after RT. Median survival was 31 months, and 2-year survival was 58%. RTOG RPA class was associated with survival (p < 0.001), but use of temozolomide during or after RT was not (p > 0.05). Conclusions In this retrospective study with inherent limitations, RTOG RPA classification was associated with survival. Further studies are necessary to confirm or refute this finding. PMID:25435851

Barker, Christopher A.; Chang, Maria; Beal, Kathryn; Chan, Timothy A.

2014-01-01

359

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

360

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

361

Radiation therapy of conjunctival and orbital lymphoid tumors  

SciTech Connect

Lymphoid tumors of the conjuctiva and orbit are rare and remain localized in the majority of cases. Sometimes it is not possible either clinically or histologically to differentiate between a non-Hodgkin's lymphoma (NHL) and benign lymphoid hyperplasia. A series of 24 patients is reported. Nineteen were classified as having malignant NHL and 5 benign hyperplasia; 1 of these 5 later developed metastases, however. All patients had systemic work-up: 18 had Stage I, 1 had Stage II, and 5 had Stage IV disease. All patients received local radiation therapy with doses of 2400 to 2750 rad in 2-3 weeks for lesions of the eyelid and conjunctiva, and between 3000 and 3750 rad in 3-4 weeks for retrobulbar lesions. A method of shielding the lens with a lead block mounted on a low vac lens is described, and the dose distribution within the eye and orbit is presented. Patients who were treated with doses higher than 3000 rad experienced conjunctivitis and skin erythema that resolved completely. No other effects of radiation on normal structures of the ocular adnexa were observed in the 20 patients who are alive and without signs of tumor 10-46 months with a median follow-up time of 22 months.

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

1984-07-01

362

Local control after fractionated stereotactic radiation therapy for brain metastases.  

PubMed

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

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

2014-11-01

363

Role of Definitive Radiation Therapy in Carcinoma of Unknown Primary in the Abdomen and Pelvis  

SciTech Connect

Objectives: Carcinoma of unknown primary (CUP) in the abdomen and pelvis is a heterogeneous group of cancers with no standard treatment. Considered by many to be incurable, these patients are often treated with chemotherapy alone. In this study, we determined the effectiveness of radiation therapy in combination with chemotherapy in patients with CUP in the abdomen and pelvis. Patients and Methods: Medical records were reviewed for 37 patients with CUP treated with radiation therapy for disease located in the soft tissues and/or nodal basins of the abdomen and pelvis at University of Texas M.D. Anderson Cancer between 2002 and 2009. All patients underwent chemotherapy, either before or concurrent with radiation therapy. Patients were selected for radiation therapy on the basis of histologic type, disease extent, and prior therapy response. Twenty patients underwent definitive radiation therapy (defined as radiation therapy targeting all known disease sites with at least 45 Gy) and 17 patients underwent palliative radiation therapy. Only 6 patients had surgical resection of their disease. Patient and treatment characteristics were extracted and the endpoints of local disease control, progression-free survival (PFS), overall survival (OS), and treatment-related toxicity incidence were analyzed. Results: The 2-year PFS and OS rates for the entire cohort were 32% and 57%, respectively. However, in patients treated with definitive radiation therapy, the rates were 48% and 76%, and 7 patients lived more than 3 years after treatment with no evidence of disease progression. Nevertheless, radiation-associated toxicity was significant in this cohort, as 40% experienced Grade 2 or higher late toxicities. Conclusions: The use of definitive radiation therapy should be considered in selected patients with CUP in the soft tissues or nodal basins of the abdomen and pelvis.

Kelly, Patrick; Das, Prajnan [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Varadhachary, Gauri R. [Department of Gastrointestinal Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Fontanilla, Hiral P.; Krishnan, Sunil; Delclos, Marc E.; Jhingran, Anuja; Eifel, Patricia J. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Crane, Christopher H., E-mail: ccrane@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States)

2012-04-01

364

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

365

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

366

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

367

Intensity-Modulated Radiation Therapy vs. 3D Conformal Radiation Therapy for Squamous Cell Carcinoma of the Anal Canal  

PubMed Central

ABSTRACT PURPOSE: We compared our institutional experience using 3D conformal radiation therapy (3DCRT) vs. IMRT (intensity-modulated radiation therapy) for anal cancer. METHODS: We performed a single-institution retrospective review of all patients with squamous cell carcinoma anal cancer treated from September 2000 through September 2011, using definitive chemoradiation with curative intent. RESULTS: This study included 89 consecutive patients (37 3DCRT, 52 IMRT). Median follow-up for all patients, IMRT patients alone, and CRT patients alone was 26.5 months (range, 3.5–133.6), 20 months (range, 3.5–125.5), and 61.9 months (range, 7.6–133.6), respectively. Three-year overall survival (OS), progression-free survival (PFS), locoregional control (LRC), and colostomy-free survival (CFS) were 91.1%, 82.3%, 90.8%, and 91.3% in the IMRT cohort and 86.1%, 72.5%, 91.9%, and 93.7% in the 3DCRT group (all P > .1). More patients in the 3DCRT group required a treatment break (11 vs. 4; P = .006), although the difference in median treatment break duration was not significant (12.2 vs. 8.0 days; P = .35). Survival did not differ based on whether a treatment break was needed (all P > .1). Acute grade ?3 nonhematologic toxicity was decreased in the IMRT cohort (21.1 vs. 59.5%; P < .0001). Acute grade ?3 skin toxicity was worse in the 3DCRT group (P < .0001), whereas an improvement in late grade ?3 gastrointestinal (GI) toxicity was observed in the IMRT patients (P = .012). CONCLUSIONS: This study is the largest thus far to compare 3DCRT and IMRT for definitive treatment of anal cancer. Although long-term outcomes did not significantly differ based on RT technique, a marked decrease in adverse effects and the need for a treatment break was achieved with IMRT. PMID:23745158

Freilich, Jessica M.; Hoffe, Sarah E.; Fulp, William; Weber, Jill M.; Almhanna, Khaldoun; Dinwoodie, William; Rao, Nikhil; Meredith, Kenneth L.; Shridhar, Ravi

2013-01-01

368

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

E-print Network

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

Fowler, Mark

369

Pioneer F Plaque Symbology  

NASA Technical Reports Server (NTRS)

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

1972-01-01

370

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

Microsoft Academic Search

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

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

2000-01-01

371

Radiation therapy of penile cancer: six to ten-year follow-up  

SciTech Connect

Ten patients with penile cancer were treated with radiation therapy between 1968 and 1973. Nine of ten remain free of disease though in 1 patient a new penile primary developed eight years after the radiation therapy and was treated by partial penectomy. One patient died following surgery for ''bleeding ulcer.'' He was free of penile cancer five years after radiation. The most common complication is urethral stricture and skin telangiectasia.

Grabstald, H.; Kelley, C.D.

1980-06-01

372

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

373

Radiation therapy for Bowen's disease of the skin  

SciTech Connect

Purpose: To assess the clinical outcome in the radiation therapy (RT) of squamous carcinoma in situ of the skin (Bowen's disease). We focused on the local control rate and the toxicity according to the biologically effective dose (BED). Methods and Materials: A retrospective review was performed on 44 patients with Bowen's disease treated at Princess Margaret Hospital from April 1985 to November 2000. RT was the primary treatment for 32 patients, whereas 12 received RT for residual disease after local ablative therapy. Lesions were located as follows: scalp, 9 patients (20%); face, 12 (27%); trunk, 6 (14%), extremity, 12 (27%), perianal, 3 (7%), and penis, 2 (5%). Orthovoltage X-rays were used in the majority (39 of 44, 89%). There was no standard fractionation regimen: some physicians prescribed high doses, as for invasive skin cancer, whereas others prescribed lower doses because of the noninvasive nature of the disease, a sensitive anatomic location (e.g., extremity), or large treatment area. Because of the variations in fractionation regimens, BED was used as a common metric for biologic effect in the comparison of different regimens and analyzed for correlation with recurrence and toxicity. Local control was defined as the lack of persistent or recurrent disease at the treated site for the follow-up period. Grade 4 toxicity was defined as necrosis (cartilage/bone damage) and/or ulceration for a duration of >3 months. Results: The mean patient age was 67.7 years, and the male/female ratio was 29:15. The median pretreatment lesion size was 2.65 cm{sup 2} (range, 0.07-34.56 cm{sup 2}). Complete remission was achieved in 42 patients, with follow-up unavailable for the remaining 2 patients. Subsequently, 3 patients experienced recurrences at 0.2, 1.1, and 1-1.5 years after complete remission. One recurrence was Bowen's disease (local); the others were squamous cell carcinoma (one local, one marginal). Four patients experienced a new squamous lesion at a distant cutaneous site. As of last follow-up, 32 patients (73%) were known to be alive. Median follow-up was 2.6 years (range, 0-11.8 years). All but 3 patients were disease-free at last follow-up, 1 of whom died with distant, but not local disease. The 5-year overall survival rate was 68%. Biologically effective dose was not associated with recurrence. The crude local control rate was 93%. There was a trend toward higher radiation doses for smaller pretreatment tumor and field sizes. The BED did not correlate with Grade 4 toxicity; however, the three cases of Grade 4 toxicity occurred in patients treated with hypofractionated regimens (dose per fraction >4 Gy) for extremity lesions. Conclusions: Radiation therapy is an effective treatment option for Bowen's disease of the skin. Local recurrences seem to be equally low in patients treated with high- and low-dose regimens. Avoiding hypofractionated regimens (dose per fraction >4 Gy) in extremity locations might reduce the risk of Grade 4 toxicity.

Lukas VanderSpek, Lauren A. [Department of Radiation Oncology, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Ontario (Canada)]. E-mail: lauren.vanderspek@lrcc.on.ca; Pond, Gregory R. [Department of Clinical Study Co-ordination and Biostatistics, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Ontario (Canada); Wells, Woodrow [Department of Radiation Oncology, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Ontario (Canada); Tsang, Richard W. [Department of Radiation Oncology, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Ontario (Canada)

2005-10-01

374

Hypofractionated Radiation Therapy for Breast Ductal Carcinoma In Situ  

SciTech Connect

Purpose: Conventional radiation therapy (RT) administered in 25 fractions after breast-conserving surgery (BCS) is the standard treatment for ductal carcinoma in situ (DCIS) of the breast. Although accelerated hypofractionated regimens in 16 fractions have been shown to be equivalent to conventional RT for invasive breast cancer, few studies have reported results of using hypofractionated RT in DCIS. Methods and Materials: In this multicenter collaborative effort, we retrospectively reviewed the records of all women with DCIS at 3 institutions treated with BCS followed by hypofractionated whole-breast RT (WBRT) delivered in 16 fractions. Results: Between 2003 and 2010, 440 patients with DCIS underwent BCS followed by hypofractionated WBRT in 16 fractions for a total dose of 42.5 Gy (2.66 Gy per fraction). Boost RT to the surgical bed was given to 125 patients (28%) at a median dose of 10 Gy in 4 fractions (2.5 Gy per fraction). After a median follow-up time of 4.4 years, 14 patients had an ipsilateral local relapse, resulting in a local recurrence-free survival of 97% at 5 years. Positive surgical margins, high nuclear grade, age less than 50 years, and a premenopausal status were all statistically associated with an increased occurrence of local recurrence. Tumor hormone receptor status, use of adjuvant hormonal therapy, and administration of additional boost RT did not have an impact on local control in our cohort. On multivariate analysis, positive margins, premenopausal status, and nuclear grade 3 tumors had a statistically significant worse local control rate. Conclusions: Hypofractionated RT using 42.5 Gy in 16 fractions provides excellent local control for patients with DCIS undergoing BCS.

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

2013-12-01

375

Real-time dosimetry in external beam radiation therapy  

PubMed Central

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

Prabhakar, Ramachandran

2013-01-01

376

Current Role of Radiation Therapy for Multiple Myeloma  

PubMed Central

Background: Radiation therapy (RT) is a treatment modality traditionally used in patients with multiple myeloma (MM), but little is known regarding the role and effectiveness of RT in the era of novel agents, i.e., immunomodulatory drugs and proteasome inhibitors. Methods: We retrospectively reviewed data from 449 consecutive MM patients seen at our institute in 2010–2012 to assess indications for RT as well as its effectiveness. Pain response was scored similarly to RTOG 0631 and used the Numerical Rating Pain Scale. Results: Among 442 evaluable patients, 149 (34%) patients and 262 sites received RT. The most common indication for RT was palliation of bone pain (n?=?109, 42%), followed by prevention/treatment of pathological fractures (n?=?73, 28%), spinal cord compression (n?=?26, 10%), and involvement of vital organs/extramedullary disease (n?=?25, 10%). Of the 55 patients evaluable for pain relief, complete and partial responses were obtained in 76.4 and 7.2%, respectively. Prior RT did not significantly decrease the median number of peripheral blood stem cells collected for autologous transplant, even when prior RT was given to both the spine and pelvis. Inadequacy of stem cell collection for autologous stem cell transplant (ASCT) was not significantly different and it occurred in 9 and 15% of patients receiving no RT and spine/pelvic RT, respectively. None of the three cases of therapy-induced acute myelogenous leukemia/MDS occurred in the RT group. Conclusion: Despite the introduction of novel effective agents in the treatment of MM, RT remains a major therapeutic component for the management in 34% of patients, and it effectively provides pain relief while not interfering with successful peripheral blood stem cell collection for ASCT. PMID:25741475

Talamo, Giampaolo; Dimaio, Christopher; Abbi, Kamal K. S.; Pandey, Manoj K.; Malysz, Jozef; Creer, Michael H.; Zhu, Junjia; Mir, Muhammad A.; Varlotto, John M.

2015-01-01

377

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

PubMed

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

Kun, Larry E; Beltran, Chris

2009-02-01

378

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

379

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

380

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

SciTech Connect

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

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

1985-04-01

381

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

382

Tumor cells, but not endothelial cells, mediate eradication of primary sarcomas by stereotactic body radiation therapy.  

PubMed

Cancer clinics currently use high-dose stereotactic body radiation therapy as a curative treatment for several kinds of cancers. However, the contribution of vascular endothelial cells to tumor response to radiation remains controversial. Using dual recombinase technology, we generated primary sarcomas in mice with targeted genetic mutations specifically in tumor cells or endothelial cells. We selectively mutated the proapoptotic gene Bax or the DNA damage response gene Atm to genetically manipulate the radiosensitivity of endothelial cells in primary soft tissue sarcomas. Bax deletion from endothelial cells did not affect radiation-induced cell death in tumor endothelial cells or sarcoma response to radiation therapy. Although Atm deletion increased endothelial cell death after radiation therapy, deletion of Atm from endothelial cells failed to enhance sarcoma eradication. In contrast, deletion of Atm from tumor cells increased sarcoma eradication by radiation therapy. These results demonstrate that tumor cells, rather than endothelial cells, are critical targets that regulate sarcoma eradication by radiation therapy. Treatment with BEZ235, a small-molecule protein kinase inhibitor, radiosensitized primary sarcomas more than the heart. These results suggest that inhibiting ATM kinase during radiation therapy is a viable strategy for radiosensitization of some tumors. PMID:25761890

Moding, Everett J; Castle, Katherine D; Perez, Bradford A; Oh, Patrick; Min, Hooney D; Norris, Hannah; Ma, Yan; Cardona, Diana M; Lee, Chang-Lung; Kirsch, David G

2015-03-11

383

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

384

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

385

An In Situ Autologous Tumor Vaccination with Combined Radiation Therapy and TLR9 Agonist Therapy  

PubMed Central

Purpose Recent studies have shown that a new generation of synthetic agonist of Toll-like receptor (TLR) 9 consisting a 3?-3?-attached structure and a dCp7-deaza-dG dinucultodie shows more potent immunostimulatory effects in both mouse and human than conventional CpG oligonucleotides. Radiation therapy (RT) provides a source of tumor antigens that are released from dying, irradiated, tumor cells without causing systemic immunosuppression. We, therefore, examined effect of combining RT with a designer synthetic agonist of TLR9 on anti-tumoral immunity, primary tumor growth retardation and metastases in a murine model of lung cancer. Methods Grouped C57BL/6 and congenic B cell deficient mice (B?/?) bearing footpad 3LL tumors were treated with PBS, TLR9 agonist, control oligonucelotide, RT or the combination of RT and TLR9 agonist. Immune phenotype of splenocytes and serum IFN-? and IL-10 levels were analyzed by FACS and ELISA, 24 h after treatment. Tumor growth, lung metastases and survival rate were monitored and tumor specific antibodies in serum and deposition in tumor tissue were measured by ELISA and immunofluorescence. Results TLR9 agonist expanded and activated B cells and plasmacytoid dendritic cells in wild-type mice and natural killer DCs (NKDCs) in B cell-deficient (B?/?) mice bearing ectopic Lewis lung adenocarcinoma (3LL). Combined RT with TLR9 agonist treatment inhibited 3LL tumor growth in both wild type and B?/? mice. A strong tumor-specific humoral immune response (titer: 1/3200) with deposition of mouse IgG auto-antibodies in tumor tissue were found in wildtype mice, whereas the number of tumor infiltrating NKDCs increased in B?/? mice following RT+ TLR9 agonist therapy. Furthermore, mice receiving combination therapy had fewer lung metastases and a higher survival than single treatment cohorts. Conclusions Combination therapy with TLR9 agonist and RT induces systemic anti-tumoral humoral response, augments tumoral infiltration of NKDCs, reduces pulmonary metastases and improves survival in a murine model of 3LL cancer. PMID:22666458

Zhang, Huagang; Liu, Laibin; Yu, Dong; Kandimalla, Ekambar R.; Sun, Hui Bin; Agrawal, Sudhir; Guha, Chandan

2012-01-01

386

10. Detail, dedication plaque on the bridge's northeast end (plaque ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. Detail, dedication plaque on the bridge's northeast end (plaque on southwest end of bridge is identical - Big Cottonwood River Bridge No. 246, Spanning Big Cottonwood River at Cottonwood Street (City Road No. 165), New Ulm, Brown County, MN

387

Objective Assessment of Image Quality VI: Imaging in Radiation Therapy  

PubMed Central

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

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

2015-01-01

388

High resolution optical calorimetry for synchrotron microbeam radiation therapy  

NASA Astrophysics Data System (ADS)

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

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

2011-03-01

389

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

390

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

391

ACOUSTIC RADIATION FORCE FOR VASCULAR CELL THERAPY: IN VITRO VALIDATION  

PubMed Central

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

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

2012-01-01

392

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.

393

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

394

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

SciTech Connect

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

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

2008-12-01

395

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

396

Association between Randall's Plaque and Calcifying Nanoparticles  

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

397

Outcomes of Pediatric Low-grade Gliomas Treated With Radiation Therapy: A Single-institution Study  

PubMed Central

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

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

2014-01-01

398

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

PubMed

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

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

2014-08-01

399

Palliative radiation therapy outcomes for cats with oral squamous cell carcinoma (1999-2005).  

PubMed

Squamous cell carcinoma (SCC) accounts for approximately 10% of all feline tumors. The purpose of this retrospective study was to describe outcomes for a group of cats with oral SCC that were treated with palliative radiation therapy. Fifty-four cats met the inclusion criteria of nonresectable, oral SCC treated with coarse fractionated megavoltage (MeV) radiation therapy. Radiation therapy for all cats was delivered with a 6 MeV linear accelerator. Total radiation doses of 24 Gray to 40 Gray were administered in three to four fractions, once-per-week over 4 to 5 weeks. Concurrent chemotherapy protocols varied and were administered at the discretion of the clinician and client. Forty-nine patients completed the planned treatment protocols. Overall mean and median survival times for cats completing the planned treatment protocols were 127 and 92 days (n = 49). Mean and median survival times of cats receiving palliative radiation therapy alone were 157 and 113 days (n = 12). Mean and median survival times of patients receiving both radiation therapy and chemotherapy were 116 and 80 days (n = 37). Patients with sublingual tumors had a median survival time of 135 days (n = 15), compared to mandibular tumors that had a median survival time of 80 days (n = 26). For the majority of patients that completed the planned treatment protocol (65%), owners reported a subjectively improved quality of life. Findings from this uncontrolled study supported the use of palliative radiation therapy for cats with nonresectable oral squamous cell carcinoma. PMID:24766180

Sabhlok, Aarti; Ayl, Rodney

2014-01-01

400

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

401

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

PubMed Central

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

2013-01-01

402

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 ... deal with when it starts to fall out. Hair loss is called “alopecia.” People lose hair only in ...

403

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

Cancer.gov

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

404

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

SciTech Connect

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

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

1986-03-01

405

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

NASA Astrophysics Data System (ADS)

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

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

2010-06-01

406

Controlling beam complexity in intensity-modulated radiation therapy  

NASA Astrophysics Data System (ADS)

External beam intensity modulated radiation therapy (IMRT) is a technique in which the spatial intensity of radiation from each beam direction can be modulated to provide superior conformality of dose to a tumor volume while sparing important normal tissues. A fundamental and potentially limiting feature of IMRT is the highly complex fields that can be created through inverse plan optimization. Highly modulated treatments are a large departure from conventional radiotherapy methods, are difficult to deliver accurately and efficiently, and can result in an undesirable increase in leakage dose being delivered to the patient. Longer deliveries may also increase the chance for patient motion during treatment and could potentially reduce the probability of controlling some tumors. The large intensity fluctuations observed in IMRT beams are often a result of the degeneracy of the optimization problem, and the types of optimization method and cost function used. This work demonstrates that beam complexity is a result of these two issues, and is dependent on the placement of dose evaluation points in the target and normal tissues. This research shows that (i) optimizing surfaces instead of discrete beamlet intensities to represent the beam can reduce the degrees of freedom in IMRT and results in much smoother beams at the expense of a slight increase in normal tissues, (ii) maximum beamlet intensity restrictions are useful for improved delivery efficiency, but may restrict the optimizer at low limits, and (iii) modulation penalties can be incorporated into the cost function to promote plan smoothness without sacrificing plan quality. Penalizing the overall plan modulation is an effective way to reduce modulation, but it falsely penalizes the desirable beam modulation as well as the undesirable modulation. To address this problem, diffusion principles are used to develop a spatially adaptive smoothing method that only penalizes the unnecessary beam modulation and can be used without degrading plan quality. This method is customizable to a variety of treatment scenarios. The clinical impact of reducing beam complexity is significant, as it can result in an improvement in delivery accuracy and efficiency, quicker optimization times, and increased robustness to point sampling and geometric uncertainty.

Matuszak, Martha Marie

407

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

Microsoft Academic Search

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

Larry E. Kun; Chris Beltran

2009-01-01

408

Intraoperative electron beam radiation therapy for recurrent locally advanced rectal or rectosigmoid carcinoma  

Microsoft Academic Search

A multimodality approach of moderate-dose to high-dose preoperative radiation therapy, surgical resection, and intraoperative electron beam radiation therapy (IORT) has been used for patients with locally recurrent rectal or rectosigmoid carcinoma. The 5-year actuarial local control and disease-free survival for 30 patients undergoing this treatment program were 26% and 19%, respectively. The most important factor predicting a favorable outcome was

Christopher G. Willett; Paul C. Shellito; Joel E. Tepper; Roseann Eliseo; Karen Convery; William C. Wood

1991-01-01

409

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.

410

Long-term regional control after radiation therapy and neck dissection for base of tongue carcinoma  

Microsoft Academic Search

Purpose: Minimal literature exists with 10-year data on neck control in advanced head and neck cancer. The purpose of this study is to determine long-term regional control for base of tongue carcinoma patients treated with primary radiation therapy plus neck dissection.Methods and Materials: Between 1981–1996, primary radiation therapy was used to treat 68 patients with squamous cell carcinoma of the

Henry J. Lee; Michael J. Zelefsky; Dennis H. Kraus; David G. Pfister; Elliot W. Strong; Adam Raben; Jatin P. Shah; Louis B. Harrison

1997-01-01

411

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.

412

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

413

Oncoplastic Surgery and Radiation Therapy for Breast Conservation: Early Outcomes  

PubMed Central

Purpose To analyze a multidisciplinary community experience with oncoplastic breast surgery (OBS) and postoperative radiation therapy (RT). Methods The records of 79 patients with localized breast cancer who underwent OBS + RT were reviewed. OBS included immediate reconstruction and contralateral mammoreduction. All patients had negative surgical margins. Whole breast RT was delivered without boost. A subset of 44 patients agreed to complete a validated quality of life survey pre-RT, post-RT, 6 months after RT, and at final follow-up assessing cosmesis and treatment satisfaction. Results Sixty seven patients (85%) were Caucasian. Median age was 62. Median interval between OBS and RT start was 9.6 weeks. Median RT dose was 46 Gy. Fourteen patients (18%) developed surgical toxicities prior to RT. Five patients (6%) developed RT toxicities. Physician rating of cosmesis post-RT was: 3% excellent, 94% good, and 4% fair. Cosmesis was rated as excellent or good by 87% of patients pre-RT, 82% post-RT, 75% at 6 months, and 88% at the final follow-up. Treatment satisfaction was rated as “total” or “somewhat” by 97% of patients pre-RT, 93% post-RT, 75% at 6 months, and 96% at final follow-up. No significant relation was found between patient or treatment-related factors and toxicity. Local control is 100% at median follow-up of 2.9 years. Conclusions OBS followed by RT resulted in acceptable toxicity and favorable physician-rated cosmesis in this large community series. Patients’ ratings of cosmesis and treatment satisfaction were initially high, decreasing at 6 months, returning near baseline at final follow-up. PMID:23799290

Maguire, Patrick D.; Nichols, Michael A.; Adams, Ashley

2013-01-01

414

Auto-propagation of contours for adaptive prostate radiation therapy  

NASA Astrophysics Data System (ADS)

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.

Chao, Ming; Xie, Yaoqin; Xing, Lei

2008-09-01

415

Clinical Outcomes of Postmastectomy Radiation Therapy After Immediate Breast Reconstruction  

SciTech Connect

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

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

2008-11-01

416

Iterative regularization in intensity-modulated radiation therapy optimization.  

PubMed

A common way to solve intensity-modulated radiation therapy (IMRT) optimization problems is to use a beamlet-based approach. The approach is usually employed in a three-step manner: first a beamlet-weight optimization problem is solved, then the fluence profiles are converted into step-and-shoot segments, and finally postoptimization of the segment weights is performed. A drawback of beamlet-based approaches is that beamlet-weight optimization problems are ill-conditioned and have to be regularized in order to produce smooth fluence profiles that are suitable for conversion. The purpose of this paper is twofold: first, to explain the suitability of solving beamlet-based IMRT problems by a BFGS quasi-Newton sequential quadratic programming method with diagonal initial Hessian estimate, and second, to empirically show that beamlet-weight optimization problems should be solved in relatively few iterations when using this optimization method. The explanation of the suitability is based on viewing the optimization method as an iterative regularization method. In iterative regularization, the optimization problem is solved approximately by iterating long enough to obtain a solution close to the optimal one, but terminating before too much noise occurs. Iterative regularization requires an optimization method that initially proceeds in smooth directions and makes rapid initial progress. Solving ten beamlet-based IMRT problems with dose-volume objectives and bounds on the beamlet-weights, we find that the considered optimization method fulfills the requirements for performing iterative regularization. After segment-weight optimization, the treatments obtained using 35 beamlet-weight iterations outperform the treatments obtained using 100 beamlet-weight iterations, both in terms of objective value and of target uniformity. We conclude that iterating too long may in fact deteriorate the quality of the deliverable plan. PMID:16485429

Carlsson, Fredrik; Forsgren, Anders

2006-01-01

417