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Sample records for based radiation therapy

  1. Radiation therapy

    International Nuclear Information System (INIS)

    Bader, J.L.; Glatstein, E.

    1987-01-01

    The radiation oncologist encounters the critically ill immunosuppressed patient in four settings. First, the newly diagnosed cancer patient presents for initial evaluation and treatment, with immunosuppression from the cancer itself, malnutrition, concomitant infectious disease, prior drug or alcohol abuse or other medical problems. Second, the previously treated cancer patient presents with metastatic or recurrent primary cancer causing local symptoms. Immune dysfunction in this setting may be due to prior chemotherapy and/or radiation as well as any of the original factors. Third, the patient previously treated with radiation presents with a life-threatening problem possibly due to complications of prior therapy. In this setting, the radiation oncologist is asked to evaluate the clinical problem and to suggest whether radiation might be causing part or all of the problem and what can be done to treat these sequelae of radiation. Fourth, the patient with a benign diagnosis (not cancer) is seen with a problem potentially emeliorated by radiation (e.g., kidney transplant rejection, preparation for transplant, or intractable rheumatoid arthritis). This chapter reviews these four issues and presents clinical and radiobiologic principles on which recommendations for therapy are based

  2. Radiation Therapy

    Science.gov (United States)

    ... radiation may be external, from special machines, or internal, from radioactive substances that a doctor places inside your body. The type of radiation therapy you receive depends on many factors, including The ...

  3. Current status of radiation therapy. Evidence-based medicine (EBM) of radiation therapy. Non-small cell lung cancer (NSCLC)

    International Nuclear Information System (INIS)

    Sumi, Minako

    2002-01-01

    The goal of radiation therapy for non-small cell lung cancer (NSCLC) is to improve the survival rate of patients without increasing treatment-related toxicity and to improve patients' quality of life. Several prospective randomized trials have demonstrated a survival advantage in combined modality treatment over radiotherapy or chemotherapy alone when a cisplatin-based chemotherapy regimen is utilized in the treatment plan. Combined modality treatment of cisplatin-based chemotherapy and radiotherapy is standard treatment for selected patients such as those with better performance status with locally or regionally advanced lung cancer including T3-T4 or N2-N3. Determining the contribution of new agents in combined modality treatment will require carefully designed and conducted clinical trials. High-dose involved field radiation therapy using 3D-conformal radiation therapy potentially enables the use of higher doses than standard radiation therapy, because less normal tissue is irradiated, and may improve local control and survival. The combination of radiotherapy with chemotherapy and dose escalation using 3D-conformal radiation therapy is also a possibility in unresectable NSCLC. In surgery cases, the results of several Phase III trials of cisplatin-based preoperative chemotherapy have suggested survival improvement. But the concept needs to be tested in a larger Phase III trial. (author)

  4. Radiation Therapy for Cancer

    Science.gov (United States)

    ... material placed in the body near cancer cells ( internal radiation therapy , also called brachytherapy ). Systemic radiation therapy uses radioactive ... material placed in the body near cancer cells (internal radiation therapy, more commonly called brachytherapy). Systemic radiation therapy uses ...

  5. Comparison of dose-volume histograms for Tomo therapy, linear accelerator-based 3D conformal radiation therapy, and intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Ji, Youn-Sang; Dong, Kyung-Rae; Kim, Chang-Bok; Choi, Seong-Kwan; Chung, Woon-Kwan; Lee, Jong-Woong

    2011-01-01

    Highlights: → Evaluation of DVH from 3D CRT, IMRT and Tomo therapy was conducted for tumor therapy. → The doses of GTV and CTV were compared using DVHs from 3D CRT, IMRT and Tomo therapy. → The GTV was higher when Tomo therapy was used, while the doses of critical organ were low. → They said that Tomo therapy satisfied the goal of radiation therapy more than the others. - Abstract: Evaluation of dose-volume histograms from three-dimensional conformal radiation therapy (3D CRT), intensity-modulated radiation therapy (IMRT), and Tomo therapy was conducted. These three modalities are among the diverse treatment systems available for tumor therapy. Three patients who received tumor therapy for a malignant oligodendroglioma in the cranium, nasopharyngeal carcinoma in the cervical neck, and prostate cancer in the pelvis were selected as study subjects. Therapy plans were made for the three patients before dose-volume histograms were obtained. The doses of the gross tumor volume (GTV) and the clinical target volume (CTV) were compared using the dose-volume histograms obtained from the LINAC-based 3D CRT, IMRT planning station (Varian Eclipse-Varian, version 8.1), and Tomo therapy planning station. In addition, the doses of critical organs in the cranium, cervix, and pelvis that should be protected were compared. The GTV was higher when Tomo therapy was used compared to 3D CRT and the LINAC-based IMRT, while the doses of critical organ tissues that required protection were low. These results demonstrated that Tomo therapy satisfied the ultimate goal of radiation therapy more than the other therapies.

  6. Ultrasound-based guidance of intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Fung, Albert Y.C.; Ayyangar, Komanduri M.; Djajaputra, David; Nehru, Ramasamy M.; Enke, Charles A.

    2006-01-01

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

  7. Radiation therapy -- skin care

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000735.htm Radiation therapy - skin care To use the sharing features on ... should treat your skin with care while receiving radiation therapy. Causes External radiation therapy uses high-powered x- ...

  8. Radiation Therapy

    Science.gov (United States)

    ... kill any cancer cells that remain. Lifetime Dose Limits There is a limit to the amount of radiation an area of ... total dose of radiation more quickly or to limit damage to healthy cells. Different ways of delivering ...

  9. The design and implementation of the radiation therapy information management system (RTIMS) based on the workflow of radiation therapy

    International Nuclear Information System (INIS)

    Wu Qinhong; Li Gaofeng; Zhong Qiuzi; Hou Xiuyu; Li Ming; Xu Yonggang; He Jingxue

    2012-01-01

    Objective: To meet the special needs of the department of radiation oncology, a radiation therapy information management system (RTIMS) has been developed as a secondary database system to supplement the Varian Varis/Aria since 2007. Methods: The RTIMS server was used to run a database and web service of Apache + PHP + MySQL. The RTIMS sever's web service could be visited with Internet Explorer (IE) to input, search, count, and print information from about 30 workstations and 20 personal computers. As some workstations were installed with Windows and IE in English only, some functions had English version. Results: In past five years, as the RTIMS was implemented in the department, some further needs were met and more practical functions were developed. And now the RTIMS almost covered the whole workflow of radiation therapy (RT). By September 2011 , recorded patients data in the RTIMS is as follows: 3900 patients, 2600 outpatient RT records, 6800 progress notes, 1900 RT summaries, 6700 charge records, 83000 workload records, 3900 plan application forms, 1600 ICRT records. etc. Conclusions: The RTIMS based on the workflow of RT has been successfully developed and clinically implemented. And it was demonstrated to be user-friendly and was proven to significantly improve the efficiency of the department. Since it is an in-house developed system, more functions can be added or modified to further enhance its potentials in research and clinical practice. (authors)

  10. Deep Inspiration Breath Hold-Based Radiation Therapy : A Clinical Review

    NARCIS (Netherlands)

    Boda-Heggemann, Judit; Knopf, Antje-Christin; Simeonova-Chergou, Anna; Wertz, Hansjörg; Stieler, Florian; Jahnke, Anika; Jahnke, Lennart; Fleckenstein, Jens; Vogel, Lena; Arns, Anna; Blessing, Manuel; Wenz, Frederik; Lohr, Frank

    2016-01-01

    Several recent developments in linear accelerator-based radiation therapy (RT) such as fast multileaf collimators, accelerated intensity modulation paradigms like volumeric modulated arc therapy and flattening filter-free (FFF) high-dose-rate therapy have dramatically shortened the duration of

  11. Simulation-based education: A narrative review of the use of VERT in radiation therapy education.

    Science.gov (United States)

    Kane, Paul

    2018-04-14

    Simulation has a long history in medical and health science training and education. The literature describing this history is extensive. The role simulation plays in many health disciplines has evolved, as has the focus of the literature around it. The Virtual Environment for Radiotherapy Training (VERT) system is a relative newcomer to radiation therapy education and, similar to the literature around radiation therapy (RT) education, is still in its infancy. This narrative review sets the scene of simulation-based education within the health sciences and considers the lessons learned from published work on VERT to date. The evidence suggests that future inquiry involving VERT should explore different ways in which VERT can be used to contribute to the skillset required by the radiation therapist of tomorrow. © 2018 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.

  12. GPU-based High-Performance Computing for Radiation Therapy

    Science.gov (United States)

    Jia, Xun; Ziegenhein, Peter; Jiang, Steve B.

    2014-01-01

    Recent developments in radiotherapy therapy demand high computation powers to solve challenging problems in a timely fashion in a clinical environment. Graphics processing unit (GPU), as an emerging high-performance computing platform, has been introduced to radiotherapy. It is particularly attractive due to its high computational power, small size, and low cost for facility deployment and maintenance. Over the past a few years, GPU-based high-performance computing in radiotherapy has experienced rapid developments. A tremendous amount of studies have been conducted, in which large acceleration factors compared with the conventional CPU platform have been observed. In this article, we will first give a brief introduction to the GPU hardware structure and programming model. We will then review the current applications of GPU in major imaging-related and therapy-related problems encountered in radiotherapy. A comparison of GPU with other platforms will also be presented. PMID:24486639

  13. GPU-based high-performance computing for radiation therapy

    International Nuclear Information System (INIS)

    Jia, Xun; Jiang, Steve B; Ziegenhein, Peter

    2014-01-01

    Recent developments in radiotherapy therapy demand high computation powers to solve challenging problems in a timely fashion in a clinical environment. The graphics processing unit (GPU), as an emerging high-performance computing platform, has been introduced to radiotherapy. It is particularly attractive due to its high computational power, small size, and low cost for facility deployment and maintenance. Over the past few years, GPU-based high-performance computing in radiotherapy has experienced rapid developments. A tremendous amount of study has been conducted, in which large acceleration factors compared with the conventional CPU platform have been observed. In this paper, we will first give a brief introduction to the GPU hardware structure and programming model. We will then review the current applications of GPU in major imaging-related and therapy-related problems encountered in radiotherapy. A comparison of GPU with other platforms will also be presented. (topical review)

  14. GPU-based high-performance computing for radiation therapy

    Science.gov (United States)

    Jia, Xun; Ziegenhein, Peter; Jiang, Steve B.

    2014-02-01

    Recent developments in radiotherapy therapy demand high computation powers to solve challenging problems in a timely fashion in a clinical environment. The graphics processing unit (GPU), as an emerging high-performance computing platform, has been introduced to radiotherapy. It is particularly attractive due to its high computational power, small size, and low cost for facility deployment and maintenance. Over the past few years, GPU-based high-performance computing in radiotherapy has experienced rapid developments. A tremendous amount of study has been conducted, in which large acceleration factors compared with the conventional CPU platform have been observed. In this paper, we will first give a brief introduction to the GPU hardware structure and programming model. We will then review the current applications of GPU in major imaging-related and therapy-related problems encountered in radiotherapy. A comparison of GPU with other platforms will also be presented.

  15. GPU-based high-performance computing for radiation therapy.

    Science.gov (United States)

    Jia, Xun; Ziegenhein, Peter; Jiang, Steve B

    2014-02-21

    Recent developments in radiotherapy therapy demand high computation powers to solve challenging problems in a timely fashion in a clinical environment. The graphics processing unit (GPU), as an emerging high-performance computing platform, has been introduced to radiotherapy. It is particularly attractive due to its high computational power, small size, and low cost for facility deployment and maintenance. Over the past few years, GPU-based high-performance computing in radiotherapy has experienced rapid developments. A tremendous amount of study has been conducted, in which large acceleration factors compared with the conventional CPU platform have been observed. In this paper, we will first give a brief introduction to the GPU hardware structure and programming model. We will then review the current applications of GPU in major imaging-related and therapy-related problems encountered in radiotherapy. A comparison of GPU with other platforms will also be presented.

  16. Hendee's radiation therapy physics

    CERN Document Server

    Pawlicki, Todd; Starkschall, George

    2016-01-01

    The publication of this fourth edition, more than ten years on from the publication of Radiation Therapy Physics third edition, provides a comprehensive and valuable update to the educational offerings in this field. Led by a new team of highly esteemed authors, building on Dr Hendee’s tradition, Hendee’s Radiation Therapy Physics offers a succinctly written, fully modernised update. Radiation physics has undergone many changes in the past ten years: intensity-modulated radiation therapy (IMRT) has become a routine method of radiation treatment delivery, digital imaging has replaced film-screen imaging for localization and verification, image-guided radiation therapy (IGRT) is frequently used, in many centers proton therapy has become a viable mode of radiation therapy, new approaches have been introduced to radiation therapy quality assurance and safety that focus more on process analysis rather than specific performance testing, and the explosion in patient-and machine-related data has necessitated an ...

  17. Radiation therapy of cancer

    International Nuclear Information System (INIS)

    Tomottogoo, G.

    1995-01-01

    The radiation therapy experienced at the hospital are classified into two sections:palliative and radically. A radically therapy can be done before or after surgery. Therapy after surgery is done when the results of the surgery have certain limits. The radiation therapy is accomplished within 2-3 weeks and 6 weeks at latest. A conclusion:1.To improving and increasing of radically radiation therapy method is necessary in the present time. 2.Monitoring, management and supervision capacity of the cancer radiation therapy for the nearest and future results should be strengthened

  18. An Approach in Radiation Therapy Treatment Planning: A Fast, GPU-Based Monte Carlo Method.

    Science.gov (United States)

    Karbalaee, Mojtaba; Shahbazi-Gahrouei, Daryoush; Tavakoli, Mohammad B

    2017-01-01

    An accurate and fast radiation dose calculation is essential for successful radiation radiotherapy. The aim of this study was to implement a new graphic processing unit (GPU) based radiation therapy treatment planning for accurate and fast dose calculation in radiotherapy centers. A program was written for parallel running based on GPU. The code validation was performed by EGSnrc/DOSXYZnrc. Moreover, a semi-automatic, rotary, asymmetric phantom was designed and produced using a bone, the lung, and the soft tissue equivalent materials. All measurements were performed using a Mapcheck dosimeter. The accuracy of the code was validated using the experimental data, which was obtained from the anthropomorphic phantom as the gold standard. The findings showed that, compared with those of DOSXYZnrc in the virtual phantom and for most of the voxels (>95%), GPU-based Monte Carlo method in dose calculation may be useful in routine radiation therapy centers as the core and main component of a treatment planning verification system.

  19. Current concepts in F18 FDG PET/CT-based Radiation Therapy planning for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Percy eLee

    2012-07-01

    Full Text Available Radiation therapy is an important component of cancer therapy for early stage as well as locally advanced lung cancer. The use of F18 FDG PET/CT has come to the forefront of lung cancer staging and overall treatment decision-making. FDG PET/CT parameters such as standard uptake value and metabolic tumor volume provide important prognostic and predictive information in lung cancer. Importantly, FDG PET/CT for radiation planning has added biological information in defining the gross tumor volume as well as involved nodal disease. For example, accurate target delineation between tumor and atelectasis is facilitated by utilizing PET and CT imaging. Furthermore, there has been meaningful progress in incorporating metabolic information from FDG PET/CT imaging in radiation treatment planning strategies such as radiation dose escalation based on standard uptake value thresholds as well as using respiratory gated PET and CT planning for improved target delineation of moving targets. In addition, PET/CT based follow-up after radiation therapy has provided the possibility of early detection of local as well as distant recurrences after treatment. More research is needed to incorporate other biomarkers such as proliferative and hypoxia biomarkers in PET as well as integrating metabolic information in adaptive, patient-centered, tailored radiation therapy.

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

    International Nuclear Information System (INIS)

    Diot, Quentin; Kavanagh, Brian; Timmerman, Robert; Miften, Moyed

    2012-01-01

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

  1. Difference of protein 53 expression based on radiation therapy response in cervical cancer

    Science.gov (United States)

    Pasaribu, H. P.; Lubis, L. I.; Dina, S.; Simanjuntak, R. Y.; Siregar, H. S.; Rivany, R.

    2018-03-01

    Cervical cancer is one of most common gynecological cancer in women and the leading cause of death in developing countries. An analytic study with the case-control design was conducted to determine the difference of p53 expression based on radiation therapy response in cervical cancer. The study was performed in Obstetric and Gynecology Department and Pathology Department of Adam Malik General Hospital Medan from January to February 2017. 15 paraffin blocks of acervical cancer patient with incomplete response were obtained as study samples, and 15 paraffin blocks of acervical cancer patient with complete response were obtained as control samples, The samples were collected by consecutive sampling, andan immunohistochemical assessment of p53 expression was done to assessapoptosis count and radiation response. Data were analyzed using Kruskal-Wallis with confidence interval 83.5% and pradiation therapy can be used as an early marker for radiation therapy response in cervical cancer.

  2. Radiation therapy for head and neck cancers a case-based review

    CERN Document Server

    Beyzadeoglu, Murat; Selek, Ugur

    2014-01-01

    This evidence-based guide to the current management of cancer cases at all head and neck sites will assist in the appropriate selection and delineation of tumor volumes/fields for intensity-modulated radiation therapy (IMRT), including volumetric modulated arc therapy (VMAT). Each tumor site-related chapter presents, from the perspective of an academic expert, several actual cases at different stages in order to clarify specific clinical concepts. The coverage includes case presentation, a case-related literature review, patient preparation, simulation, contouring, treatment planning, treatment delivery, and follow-up. The text is accompanied by illustrations ranging from slice-by-slice delineations on planning CT images to finalized plan evaluations based on detailed acceptance criteria. The book will be of value for residents, fellows, practicing radiation oncologists, and medical physicists interested in clinical radiation oncology.

  3. Radiation Therapy - Multiple Languages

    Science.gov (United States)

    ... W XYZ List of All Topics All Radiation Therapy - Multiple Languages To use the sharing features on this page, ... Information Translations Vietnamese (Tiếng Việt) Expand Section Radiation Therapy - Tiếng Việt (Vietnamese) ... Health Information Translations Characters not displaying correctly on this page? See language display issues . Return to the MedlinePlus Health Information ...

  4. mRNA-based vaccines synergize with radiation therapy to eradicate established tumors

    International Nuclear Information System (INIS)

    Fotin-Mleczek, Mariola; Zanzinger, Kai; Heidenreich, Regina; Lorenz, Christina; Kowalczyk, Aleksandra; Kallen, Karl-Josef; Huber, Stephan M

    2014-01-01

    The eradication of large, established tumors by active immunotherapy is a major challenge because of the numerous cancer evasion mechanisms that exist. This study aimed to establish a novel combination therapy consisting of messenger RNA (mRNA)-based cancer vaccines and radiation, which would facilitate the effective treatment of established tumors with aggressive growth kinetics. The combination of a tumor-specific mRNA-based vaccination with radiation was tested in two syngeneic tumor models, a highly immunogenic E.G7-OVA and a low immunogenic Lewis lung cancer (LLC). The molecular mechanism induced by the combination therapy was evaluated via gene expression arrays as well as flow cytometry analyses of tumor infiltrating cells. In both tumor models we demonstrated that a combination of mRNA-based immunotherapy with radiation results in a strong synergistic anti-tumor effect. This was manifested as either complete tumor eradication or delay in tumor growth. Gene expression analysis of mouse tumors revealed a variety of substantial changes at the tumor site following radiation. Genes associated with antigen presentation, infiltration of immune cells, adhesion, and activation of the innate immune system were upregulated. A combination of radiation and immunotherapy induced significant downregulation of tumor associated factors and upregulation of tumor suppressors. Moreover, combination therapy significantly increased CD4 + , CD8 + and NKT cell infiltration of mouse tumors. Our data provide a scientific rationale for combining immunotherapy with radiation and provide a basis for the development of more potent anti-cancer therapies. The online version of this article (doi:10.1186/1748-717X-9-180) contains supplementary material, which is available to authorized users

  5. Radio frequency radiation-induced hyperthermia using Si nanoparticle-based sensitizers for mild cancer therapy

    Science.gov (United States)

    Tamarov, Konstantin P.; Osminkina, Liubov A.; Zinovyev, Sergey V.; Maximova, Ksenia A.; Kargina, Julia V.; Gongalsky, Maxim B.; Ryabchikov, Yury; Al-Kattan, Ahmed; Sviridov, Andrey P.; Sentis, Marc; Ivanov, Andrey V.; Nikiforov, Vladimir N.; Kabashin, Andrei V.; Timoshenko, Victor Yu

    2014-11-01

    Offering mild, non-invasive and deep cancer therapy modality, radio frequency (RF) radiation-induced hyperthermia lacks for efficient biodegradable RF sensitizers to selectively target cancer cells and thus avoid side effects. Here, we assess crystalline silicon (Si) based nanomaterials as sensitizers for the RF-induced therapy. Using nanoparticles produced by mechanical grinding of porous silicon and ultraclean laser-ablative synthesis, we report efficient RF-induced heating of aqueous suspensions of the nanoparticles to temperatures above 45-50°C under relatively low nanoparticle concentrations (Combined with the possibility of involvement of parallel imaging and treatment channels based on unique optical properties of Si-based nanomaterials, the proposed method promises a new landmark in the development of new modalities for mild cancer therapy.

  6. Individualized Positron Emission Tomography–Based Isotoxic Accelerated Radiation Therapy Is Cost-Effective Compared With Conventional Radiation Therapy: A Model-Based Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Bongers, Mathilda L., E-mail: ml.bongers@vumc.nl [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); Coupé, Veerle M.H. [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); De Ruysscher, Dirk [Radiation Oncology University Hospitals Leuven/KU Leuven, Leuven (Belgium); Department of Radiation Oncology, GROW Research Institute, Maastricht University Medical Center, Maastricht (Netherlands); Oberije, Cary; Lambin, Philippe [Department of Radiation Oncology, GROW Research Institute, Maastricht University Medical Center, Maastricht (Netherlands); Uyl-de Groot, Cornelia A. [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); Institute for Medical Technology Assessment, Erasmus University Rotterdam, Rotterdam (Netherlands)

    2015-03-15

    Purpose: To evaluate long-term health effects, costs, and cost-effectiveness of positron emission tomography (PET)-based isotoxic accelerated radiation therapy treatment (PET-ART) compared with conventional fixed-dose CT-based radiation therapy treatment (CRT) in non-small cell lung cancer (NSCLC). Methods and Materials: Our analysis uses a validated decision model, based on data of 200 NSCLC patients with inoperable stage I-IIIB. Clinical outcomes, resource use, costs, and utilities were obtained from the Maastro Clinic and the literature. Primary model outcomes were the difference in life-years (LYs), quality-adjusted life-years (QALYs), costs, and the incremental cost-effectiveness and cost/utility ratio (ICER and ICUR) of PET-ART versus CRT. Model outcomes were obtained from averaging the predictions for 50,000 simulated patients. A probabilistic sensitivity analysis and scenario analyses were carried out. Results: The average incremental costs per patient of PET-ART were €569 (95% confidence interval [CI] €−5327-€6936) for 0.42 incremental LYs (95% CI 0.19-0.61) and 0.33 QALYs gained (95% CI 0.13-0.49). The base-case scenario resulted in an ICER of €1360 per LY gained and an ICUR of €1744 per QALY gained. The probabilistic analysis gave a 36% probability that PET-ART improves health outcomes at reduced costs and a 64% probability that PET-ART is more effective at slightly higher costs. Conclusion: On the basis of the available data, individualized PET-ART for NSCLC seems to be cost-effective compared with CRT.

  7. User requirements on CT-based computed dose planning systems in radiation therapy

    International Nuclear Information System (INIS)

    Dahlin, H.

    1983-01-01

    The expanding use of computers in radiation therapy procedures, especially the rapidly increasing use of digital CT-information, necessitates the coordination of the different systems in order to facilitate their developments. In order to define necessary demands for tomorrow a Nordic cooperation was initiated in 1981 by NORDFORSK (Nordic co-operative organisation for applied research), and a group of physicians and physicists having their daily work in this field of medicine and physics was invited to produce a report on 'User requirements on CT-based computed dose planning systems in radiation therapy'. The work has been done within the frame of NORDFORSK's activities and has been independent of the existing commissions and associations in the radiology field, but it has taken into consideration recommendations that have been given by or are being produced by other organizations. (Auth.)

  8. Visual outcome after fractionated stereotactic radiation therapy of benign anterior skull base tumors

    DEFF Research Database (Denmark)

    Astradsson, Arnar; Wiencke, Anne Katrine; Munck af Rosenschold, Per

    2014-01-01

    To determine visual outcome including the occurrence of radiation induced optic neuropathy (RION) as well as tumor control after fractionated stereotactic radiation therapy (FSRT) of benign anterior skull base meningiomas or pituitary adenomas. Thirty-nine patients treated with FSRT for anterior...... skull base meningiomas and 55 patients treated with FSRT for pituitary adenomas between January 1999 and December 2009 with at least 2 years follow-up were included. Patients were followed up prospectively with magnetic resonance imaging scans, visual acuity and visual field examinations. RION was found...... in four (10%) patients with anterior skull base meningiomas and seven patients (13%) with pituitary adenomas. The five-year actuarial freedom from 25% RION visual field loss was 94% following FSRT. Actuarial 2-, 5- and 10-year tumor control rates were 100, 88.4 and 64.5% for anterior skull base...

  9. Dose–Volume Relationships Associated With Temporal Lobe Radiation Necrosis After Skull Base Proton Beam Therapy

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Mark W., E-mail: markmcdonaldmd@gmail.com [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana (United States); Indiana University Health Proton Therapy Center, Bloomington, Indiana (United States); Linton, Okechukwu R. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana (United States); Calley, Cynthia S.J. [Department of Biostatistics, Indiana University School of Medicine, Indianapolis, Indiana (United States)

    2015-02-01

    higher dose. The EC50 model provides suggested dose–volume temporal lobe constraints for conventionally fractionated high-dose skull base radiation therapy.

  10. Radiation Therapy for Lung Cancer

    Science.gov (United States)

    ... of the lung cancer and your overall health. Radiation Therapy Radiation is a high-energy X-ray that ... surgery, chemotherapy or both depending upon the circumstances. Radiation therapy works within cancer cells by damaging their ability ...

  11. Radiation Therapy: Additional Treatment Options

    Science.gov (United States)

    ... novel targeted therapies can act as radiosensitizers. Systemic Radiation Therapy Certain cancers may be treated with radioactive drugs ... intravenous). This type of treatment is called systemic radiation therapy because the medicine goes to the entire body. ...

  12. Monte Carlo-based dose calculation engine for minibeam radiation therapy.

    Science.gov (United States)

    Martínez-Rovira, I; Sempau, J; Prezado, Y

    2014-02-01

    Minibeam radiation therapy (MBRT) is an innovative radiotherapy approach based on the well-established tissue sparing effect of arrays of quasi-parallel micrometre-sized beams. In order to guide the preclinical trials in progress at the European Synchrotron Radiation Facility (ESRF), a Monte Carlo-based dose calculation engine has been developed and successfully benchmarked with experimental data in anthropomorphic phantoms. Additionally, a realistic example of treatment plan is presented. Despite the micron scale of the voxels used to tally dose distributions in MBRT, the combination of several efficiency optimisation methods allowed to achieve acceptable computation times for clinical settings (approximately 2 h). The calculation engine can be easily adapted with little or no programming effort to other synchrotron sources or for dose calculations in presence of contrast agents. Copyright © 2013 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  13. Neuropsychological function in adults after high dose fractionated radiation therapy of skull base tumors

    International Nuclear Information System (INIS)

    Glosser, Guila; McManus, Pat; Munzenrider, John; Austin-Seymour, Mary; Fullerton, Barbara; Adams, Judy; Urie, Marcia M.

    1997-01-01

    Purpose: To evaluate the long term effects of high dose fractionated radiation therapy on brain functioning prospectively in adults without primary brain tumors. Methods and Materials: Seventeen patients with histologically confirmed chordomas and low grade chondrosarcomas of the skull base were evaluated with neuropsychological measures of intelligence, language, memory, attention, motor function and mood following surgical resection/biopsy of the tumor prior to irradiation, and then at about 6 months, 2 years and 4 years following completion of treatment. None received chemotherapy. Results: In the patients without tumor recurrence or radiation necrosis, there were no indications of adverse effects on cognitive functioning in the post-acute through the late stages after brain irradiation. Even in patients who received doses of radiation up to 66 Cobalt Gy equivalent through nondiseased (temporal lobe) brain tissue, memory and cognitive functioning remained stable for up to 5 years after treatment. A mild decline in psycho-motor speed was seen in more than half of the patients, and motor slowing was related to higher radiation doses in midline and temporal lobe brain structures. Conclusion: Results suggest that in adults, tolerance for focused radiation is relatively high in cortical brain structures

  14. SU-F-J-178: A Computer Simulation Model Observer for Task-Based Image Quality Assessment in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Dolly, S; Mutic, S; Anastasio, M; Li, H [Washington University School of Medicine, Saint Louis, MO (United States); Yu, L [Mayo Clinic, Rochester, MN (United States)

    2016-06-15

    Purpose: Traditionally, image quality in radiation therapy is assessed subjectively or by utilizing physically-based metrics. Some model observers exist for task-based medical image quality assessment, but almost exclusively for diagnostic imaging tasks. As opposed to disease diagnosis, the task for image observers in radiation therapy is to utilize the available images to design and deliver a radiation dose which maximizes patient disease control while minimizing normal tissue damage. The purpose of this study was to design and implement a new computer simulation model observer to enable task-based image quality assessment in radiation therapy. Methods: A modular computer simulation framework was developed to resemble the radiotherapy observer by simulating an end-to-end radiation therapy treatment. Given images and the ground-truth organ boundaries from a numerical phantom as inputs, the framework simulates an external beam radiation therapy treatment and quantifies patient treatment outcomes using the previously defined therapeutic operating characteristic (TOC) curve. As a preliminary demonstration, TOC curves were calculated for various CT acquisition and reconstruction parameters, with the goal of assessing and optimizing simulation CT image quality for radiation therapy. Sources of randomness and bias within the system were analyzed. Results: The relationship between CT imaging dose and patient treatment outcome was objectively quantified in terms of a singular value, the area under the TOC (AUTOC) curve. The AUTOC decreases more rapidly for low-dose imaging protocols. AUTOC variation introduced by the dose optimization algorithm was approximately 0.02%, at the 95% confidence interval. Conclusion: A model observer has been developed and implemented to assess image quality based on radiation therapy treatment efficacy. It enables objective determination of appropriate imaging parameter values (e.g. imaging dose). Framework flexibility allows for incorporation

  15. Involved Node Radiation Therapy

    DEFF Research Database (Denmark)

    Maraldo, Maja V; Aznar, Marianne C; Vogelius, Ivan R

    2012-01-01

    PURPOSE: The involved node radiation therapy (INRT) strategy was introduced for patients with Hodgkin lymphoma (HL) to reduce the risk of late effects. With INRT, only the originally involved lymph nodes are irradiated. We present treatment outcome in a retrospective analysis using this strategy...... to 36 Gy). Patients attended regular follow-up visits until 5 years after therapy. RESULTS: The 4-year freedom from disease progression was 96.4% (95% confidence interval: 92.4%-100.4%), median follow-up of 50 months (range: 4-71 months). Three relapses occurred: 2 within the previous radiation field......, and 1 in a previously uninvolved region. The 4-year overall survival was 94% (95% confidence interval: 88.8%-99.1%), median follow-up of 58 months (range: 4-91 months). Early radiation therapy toxicity was limited to grade 1 (23.4%) and grade 2 (13.8%). During follow-up, 8 patients died, none from HL, 7...

  16. Image-based modeling of tumor shrinkage in head and neck radiation therapy

    International Nuclear Information System (INIS)

    Chao Ming; Xie Yaoqin; Moros, Eduardo G.; Le, Quynh-Thu; Xing Lei

    2010-01-01

    Purpose: Understanding the kinetics of tumor growth/shrinkage represents a critical step in quantitative assessment of therapeutics and realization of adaptive radiation therapy. This article presents a novel framework for image-based modeling of tumor change and demonstrates its performance with synthetic images and clinical cases. Methods: Due to significant tumor tissue content changes, similarity-based models are not suitable for describing the process of tumor volume changes. Under the hypothesis that tissue features in a tumor volume or at the boundary region are partially preserved, the kinetic change was modeled in two steps: (1) Autodetection of homologous tissue features shared by two input images using the scale invariance feature transformation (SIFT) method; and (2) establishment of a voxel-to-voxel correspondence between the images for the remaining spatial points by interpolation. The correctness of the tissue feature correspondence was assured by a bidirectional association procedure, where SIFT features were mapped from template to target images and reversely. A series of digital phantom experiments and five head and neck clinical cases were used to assess the performance of the proposed technique. Results: The proposed technique can faithfully identify the known changes introduced when constructing the digital phantoms. The subsequent feature-guided thin plate spline calculation reproduced the ''ground truth'' with accuracy better than 1.5 mm. For the clinical cases, the new algorithm worked reliably for a volume change as large as 30%. Conclusions: An image-based tumor kinetic algorithm was developed to model the tumor response to radiation therapy. The technique provides a practical framework for future application in adaptive radiation therapy.

  17. Deep Inspiration Breath Hold—Based Radiation Therapy: A Clinical Review

    Energy Technology Data Exchange (ETDEWEB)

    Boda-Heggemann, Judit, E-mail: judit.boda-heggemann@umm.de [Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany); Knopf, Antje-Christin [The Institute of Cancer Research, Royal Cancer Hospital, London (United Kingdom); Simeonova-Chergou, Anna; Wertz, Hansjörg; Stieler, Florian; Jahnke, Anika; Jahnke, Lennart; Fleckenstein, Jens; Vogel, Lena; Arns, Anna; Blessing, Manuel; Wenz, Frederik; Lohr, Frank [Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany)

    2016-03-01

    Several recent developments in linear accelerator–based radiation therapy (RT) such as fast multileaf collimators, accelerated intensity modulation paradigms like volumeric modulated arc therapy and flattening filter-free (FFF) high-dose-rate therapy have dramatically shortened the duration of treatment fractions. Deliverable photon dose distributions have approached physical complexity limits as a consequence of precise dose calculation algorithms and online 3-dimensional image guided patient positioning (image guided RT). Simultaneously, beam quality and treatment speed have continuously been improved in particle beam therapy, especially for scanned particle beams. Applying complex treatment plans with steep dose gradients requires strategies to mitigate and compensate for motion effects in general, particularly breathing motion. Intrafractional breathing-related motion results in uncertainties in dose delivery and thus in target coverage. As a consequence, generous margins have been used, which, in turn, increases exposure to organs at risk. Particle therapy, particularly with scanned beams, poses additional problems such as interplay effects and range uncertainties. Among advanced strategies to compensate breathing motion such as beam gating and tracking, deep inspiration breath hold (DIBH) gating is particularly advantageous in several respects, not only for hypofractionated, high single-dose stereotactic body RT of lung, liver, and upper abdominal lesions but also for normofractionated treatment of thoracic tumors such as lung cancer, mediastinal lymphomas, and breast cancer. This review provides an in-depth discussion of the rationale and technical implementation of DIBH gating for hypofractionated and normofractionated RT of intrathoracic and upper abdominal tumors in photon and proton RT.

  18. Radiation therapy physics

    CERN Document Server

    1995-01-01

    The aim of this book is to provide a uniquely comprehensive source of information on the entire field of radiation therapy physics. The very significant advances in imaging, computational, and accelerator technologies receive full consideration, as do such topics as the dosimetry of radiolabeled antibodies and dose calculation models. The scope of the book and the expertise of the authors make it essential reading for interested physicians and physicists and for radiation dosimetrists.

  19. Interactive Decision-Support Tool for Risk-Based Radiation Therapy Plan Comparison for Hodgkin Lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Brodin, N. Patrik [Department of Radiation Oncology, Albert Einstein College of Medicine of Yeshiva University, New York, New York (United States); Maraldo, Maja V., E-mail: dra.maraldo@gmail.com [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Aznar, Marianne C. [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Niels Bohr Institute, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Vogelius, Ivan R. [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Petersen, Peter M. [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Department of Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Department of Hematology, Rigshospitalet, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Bentzen, Søren M. [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Department of Human Oncology, University of Wisconsin Medical School, Madison, Wisconsin (United States); Specht, Lena [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Department of Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Department of Hematology, Rigshospitalet, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark)

    2014-02-01

    Purpose: To present a novel tool that allows quantitative estimation and visualization of the risk of various relevant normal tissue endpoints to aid in treatment plan comparison and clinical decision making in radiation therapy (RT) planning for Hodgkin lymphoma (HL). Methods and Materials: A decision-support tool for risk-based, individualized treatment plan comparison is presented. The tool displays dose–response relationships, derived from published clinical data, for a number of relevant side effects and thereby provides direct visualization of the trade-off between these endpoints. The Quantitative Analyses of Normal Tissue Effects in the Clinic reports were applied, complemented with newer data where available. A “relevance score” was assigned to each data source, reflecting how relevant the input data are to current RT for HL. Results: The tool is applied to visualize the local steepness of dose–response curves to drive the reoptimization of a volumetric modulated arc therapy treatment plan for an HL patient with head-and-neck involvement. We also use this decision-support tool to visualize and quantitatively evaluate the trade-off between a 3-dimensional conformal RT plan and a volumetric modulated arc therapy plan for a patient with mediastinal HL. Conclusion: This multiple-endpoint decision-support tool provides quantitative risk estimates to supplement the clinical judgment of the radiation oncologist when comparing different RT options.

  20. Applications of Machine Learning for Radiation Therapy.

    Science.gov (United States)

    Arimura, Hidetaka; Nakamoto, Takahiro

    2016-01-01

    Radiation therapy has been highly advanced as image guided radiation therapy (IGRT) by making advantage of image engineering technologies. Recently, novel frameworks based on image engineering technologies as well as machine learning technologies have been studied for sophisticating the radiation therapy. In this review paper, the author introduces several researches of applications of machine learning for radiation therapy. For examples, a method to determine the threshold values for standardized uptake value (SUV) for estimation of gross tumor volume (GTV) in positron emission tomography (PET) images, an approach to estimate the multileaf collimator (MLC) position errors between treatment plans and radiation delivery time, and prediction frameworks for esophageal stenosis and radiation pneumonitis risk after radiation therapy are described. Finally, the author introduces seven issues that one should consider when applying machine learning models to radiation therapy.

  1. Automatic atlas based electron density and structure contouring for MRI-based prostate radiation therapy on the cloud

    International Nuclear Information System (INIS)

    Dowling, J A; Burdett, N; Chandra, S; Rivest-Hénault, D; Ghose, S; Salvado, O; Fripp, J; Greer, P B; Sun, J; Parker, J; Pichler, P; Stanwell, P

    2014-01-01

    Our group have been developing methods for MRI-alone prostate cancer radiation therapy treatment planning. To assist with clinical validation of the workflow we are investigating a cloud platform solution for research purposes. Benefits of cloud computing can include increased scalability, performance and extensibility while reducing total cost of ownership. In this paper we demonstrate the generation of DICOM-RT directories containing an automatic average atlas based electron density image and fast pelvic organ contouring from whole pelvis MR scans.

  2. Automatic Atlas Based Electron Density and Structure Contouring for MRI-based Prostate Radiation Therapy on the Cloud

    Science.gov (United States)

    Dowling, J. A.; Burdett, N.; Greer, P. B.; Sun, J.; Parker, J.; Pichler, P.; Stanwell, P.; Chandra, S.; Rivest-Hénault, D.; Ghose, S.; Salvado, O.; Fripp, J.

    2014-03-01

    Our group have been developing methods for MRI-alone prostate cancer radiation therapy treatment planning. To assist with clinical validation of the workflow we are investigating a cloud platform solution for research purposes. Benefits of cloud computing can include increased scalability, performance and extensibility while reducing total cost of ownership. In this paper we demonstrate the generation of DICOM-RT directories containing an automatic average atlas based electron density image and fast pelvic organ contouring from whole pelvis MR scans.

  3. Modeling Internal Radiation Therapy

    NARCIS (Netherlands)

    van den Broek, Egon; Schouten, Theo E.; Pellegrini, M.; Fred, A.; Filipe, J.; Gamboa, H.

    2011-01-01

    A new technique is described to model (internal) radiation therapy. It is founded on morphological processing, in particular distance transforms. Its formal basis is presented as well as its implementation via the Fast Exact Euclidean Distance (FEED) transform. Its use for all variations of internal

  4. Current perspectives of radiation therapy. History of radiation therapy

    International Nuclear Information System (INIS)

    Itami, Jun

    2011-01-01

    More than 100 years have passed since the discovery of X-Strahlen by Roentgen. The history of radiation therapy has evolved under mutual stimulating relationships of the external beam radiation therapy by X-ray tubes and accelerators, and the internal radiation therapy employing radium and other radionuclides. The currently employed technologies in radiation therapy have its origin already till nineteen sixties and the development of physics and engineering have realized the original concept. (author)

  5. GPU-based ultra-fast direct aperture optimization for online adaptive radiation therapy

    Science.gov (United States)

    Men, Chunhua; Jia, Xun; Jiang, Steve B.

    2010-08-01

    Online adaptive radiation therapy (ART) has great promise to significantly reduce normal tissue toxicity and/or improve tumor control through real-time treatment adaptations based on the current patient anatomy. However, the major technical obstacle for clinical realization of online ART, namely the inability to achieve real-time efficiency in treatment re-planning, has yet to be solved. To overcome this challenge, this paper presents our work on the implementation of an intensity-modulated radiation therapy (IMRT) direct aperture optimization (DAO) algorithm on the graphics processing unit (GPU) based on our previous work on the CPU. We formulate the DAO problem as a large-scale convex programming problem, and use an exact method called the column generation approach to deal with its extremely large dimensionality on the GPU. Five 9-field prostate and five 5-field head-and-neck IMRT clinical cases with 5 × 5 mm2 beamlet size and 2.5 × 2.5 × 2.5 mm3 voxel size were tested to evaluate our algorithm on the GPU. It takes only 0.7-3.8 s for our implementation to generate high-quality treatment plans on an NVIDIA Tesla C1060 GPU card. Our work has therefore solved a major problem in developing ultra-fast (re-)planning technologies for online ART.

  6. Replanning Criteria and Timing Definition for Parotid Protection-Based Adaptive Radiation Therapy in Nasopharyngeal Carcinoma

    Directory of Open Access Journals (Sweden)

    Wei-Rong Yao

    2015-01-01

    Full Text Available The goal of this study was to evaluate real-time volumetric and dosimetric changes of the parotid gland so as to determine replanning criteria and timing for parotid protection-based adaptive radiation therapy in nasopharyngeal carcinoma. Fifty NPC patients were treated with helical tomotherapy; volumetric and dosimetric (Dmean, V1, and D50 changes of the parotid gland at the 1st, 6th, 11th, 16th, 21st, 26th, 31st, and 33rd fractions were evaluated. The clinical parameters affecting these changes were studied by analyses of variance methods for repeated measures. Factors influencing the actual parotid dose were analyzed by a multivariate logistic regression model. The cut-off values predicting parotid overdose were developed from receiver operating characteristic curves and judged by combining them with a diagnostic test consistency check. The median absolute value and percentage of parotid volume reduction were 19.51 cm3 and 35%, respectively. The interweekly parotid volume varied significantly (p<0.05. The parotid Dmean, V1, and D50 increased by 22.13%, 39.42%, and 48.45%, respectively. The actual parotid dose increased by an average of 11.38% at the end of radiation therapy. Initial parotid volume, initial parotid Dmean, and weight loss rate are valuable indicators for parotid protection-based replanning.

  7. Interactive Decision-Support Tool for Risk-Based Radiation Therapy Plan Comparison for Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    Brodin, N. Patrik; Maraldo, Maja V.; Aznar, Marianne C.

    2014-01-01

    PURPOSE: To present a novel tool that allows quantitative estimation and visualization of the risk of various relevant normal tissue endpoints to aid in treatment plan comparison and clinical decision making in radiation therapy (RT) planning for Hodgkin lymphoma (HL). METHODS AND MATERIALS...... and a volumetric modulated arc therapy plan for a patient with mediastinal HL. CONCLUSION: This multiple-endpoint decision-support tool provides quantitative risk estimates to supplement the clinical judgment of the radiation oncologist when comparing different RT options....

  8. Radiation Therapy for Skin Cancer

    Science.gov (United States)

    ... make sure they are safe to use during radiation therapy. • Eat a balanced diet. If food tastes funny ... melanoma.org Skin Cancer Foundation www.skincancer.org Radiation Therapy Answers www.rtanswers.org LEARNING ABOUT CLINICAL TRIALS ...

  9. Evaluation of a GEM and CAT-based detector for radiation therapy beam monitoring

    International Nuclear Information System (INIS)

    Brahme, A.; Danielsson, M.; Iacobaeus, C.; Ostling, J.; Peskov, V.; Wallmark, M.

    2000-01-01

    We are developing a radiation therapy beam monitor for the Karolinska Institute. This monitor will consist of two consecutive detectors confined in one gas chamber: a 'keV-photon detector', which will allow diagnostic quality visualization of the patient, and a 'MeV-photon detector', that will measure the absolute intensity of the therapy beam and its position with respect to the patient. Both detectors are based on highly radiation resistant gas and solid photon to electron converters, combined with GEMs and a CAT as amplification structures. We have performed systematic studies of the high-rate characteristics of the GEM and the CAT, as well as tested the electron transfer through these electron multipliers and various types of converters. The tests show that the GEM and the CAT satisfy all requirements for the beam monitoring system. As a result of these studies we successfully developed and tested a full section of the beam monitor equipped with a MeV-photon converter placed between the GEM and the CAT

  10. Advances in radiation therapy dosimetry

    OpenAIRE

    Paliwal, Bhudatt; Tewatia, Dinesh

    2009-01-01

    During the last decade, there has been an explosion of new radiation therapy planning and delivery tools. We went through a rapid transition from conventional three-dimensional (3D) conformal radiation therapy to intensity-modulated radiation therapy (IMRT) treatments, and additional new techniques for motion-adaptive radiation therapy are being introduced. These advances push the frontiers in our effort to provide better patient care; and with the addition of IMRT, temporal dimensions are ma...

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

    International Nuclear Information System (INIS)

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

    1997-01-01

    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 base of tongue. Neck dissection was added for those who presented with palpable lymph node metastases. The T-stage distribution was T1, 17; T2, 32; T3, 17; and T4, 2. The N-stage distribution was N0, 10; N1, 24; N2a, 6; N2b, 11, N2c, 8; N3, 7; and Nx, 2. Ages ranged from 35 to 77 (median 55 years) among the 59 males and nine females. Therapy generally consisted of initial external beam irradiation to the primary site (54 Gy) and neck (50 Gy). Clinically positive necks were boosted to 60 Gy with external beam irradiation. Three weeks later, the base of tongue was boosted with an Ir-192 interstitial implant (20-30 Gy). A neck dissection was done at the same anesthesia for those who presented with clinically positive necks, even if a complete clinical neck response was achieved with external beam irradiation. Neoadjuvant cisplatin-based chemotherapy was administered to nine patients who would have required a total laryngectomy if their primary tumors had been surgically managed. The median follow-up was 36 months with a range from 1 to 151 months. Eleven patients were followed for over 8 years. No patients were lost to follow-up. Results: Actuarial 5- and 10-year neck control was 96% overall, 86% after radiation alone, and 100% after radiation plus neck dissection. Pathologically negative neck specimens were observed in 70% of necks dissected after external beam irradiation. The remaining 30% of dissected necks were pathologically positive. These specimens contained multiple positive nodes in 83% despite a 56% overall complete clinical neck response rate to irradiation

  12. Deep Inspiration Breath Hold-Based Radiation Therapy: A Clinical Review.

    Science.gov (United States)

    Boda-Heggemann, Judit; Knopf, Antje-Christin; Simeonova-Chergou, Anna; Wertz, Hansjörg; Stieler, Florian; Jahnke, Anika; Jahnke, Lennart; Fleckenstein, Jens; Vogel, Lena; Arns, Anna; Blessing, Manuel; Wenz, Frederik; Lohr, Frank

    2016-03-01

    Several recent developments in linear accelerator-based radiation therapy (RT) such as fast multileaf collimators, accelerated intensity modulation paradigms like volumeric modulated arc therapy and flattening filter-free (FFF) high-dose-rate therapy have dramatically shortened the duration of treatment fractions. Deliverable photon dose distributions have approached physical complexity limits as a consequence of precise dose calculation algorithms and online 3-dimensional image guided patient positioning (image guided RT). Simultaneously, beam quality and treatment speed have continuously been improved in particle beam therapy, especially for scanned particle beams. Applying complex treatment plans with steep dose gradients requires strategies to mitigate and compensate for motion effects in general, particularly breathing motion. Intrafractional breathing-related motion results in uncertainties in dose delivery and thus in target coverage. As a consequence, generous margins have been used, which, in turn, increases exposure to organs at risk. Particle therapy, particularly with scanned beams, poses additional problems such as interplay effects and range uncertainties. Among advanced strategies to compensate breathing motion such as beam gating and tracking, deep inspiration breath hold (DIBH) gating is particularly advantageous in several respects, not only for hypofractionated, high single-dose stereotactic body RT of lung, liver, and upper abdominal lesions but also for normofractionated treatment of thoracic tumors such as lung cancer, mediastinal lymphomas, and breast cancer. This review provides an in-depth discussion of the rationale and technical implementation of DIBH gating for hypofractionated and normofractionated RT of intrathoracic and upper abdominal tumors in photon and proton RT. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Rapid block matching based nonlinear registration on GPU for image guided radiation therapy

    Science.gov (United States)

    Wang, An; Disher, Brandon; Carnes, Greg; Peters, Terry M.

    2010-02-01

    To compensate for non-uniform deformation due to patient motion within and between fractions in image guided radiation therapy, a block matching technique was adapted and implemented on a standard graphics processing unit (GPU) to determine the displacement vector field that maps the nonlinear transformation between successive CT images. Normalized cross correlation (NCC) was chosen as the similarity metric for the matching step, with regularization of the displacement vector field being performed by Gaussian smoothing. A multi-resolution framework was adopted to further improve the performance of the algorithm. The nonlinear registration algorithm was first applied to estimate the intrafractional motion from 4D lung CT images. It was also used to calculate the inter-fractional organ deformation between planning CT (PCT) and Daily Cone Beam CT (CBCT) images of thorax. For both experiments, manual landmark-based evaluation was performed to quantify the registration performance. In 4D CT registration, the mean TRE of 5 cases was 1.75 mm. In PCT-CBCT registration, the TRE of one case was 2.26mm. Compared to the CPU-based AtamaiWarp program, our GPU-based implementation achieves comparable registration accuracy and is ~25 times faster. The results highlight the potential utility of our algorithm for online adaptive radiation treatment.

  14. Principles of radiation therapy

    International Nuclear Information System (INIS)

    Richter, M.P.; Share, F.S.; Goodman, R.L.

    1985-01-01

    Radiation oncology now represents the integration of knowledge obtained over an 80-year period from the physics and biology laboratories and the medical clinic. Such integration is recent; until the supervoltage era following World War II, the chief developments in these three areas for the most part were realized independently. The physics and engineering laboratories have now developed a dependable family of sources of ionizing radiations that can be precisely directed at tumor volumes at various depths within the body. The biology laboratory has provided the basic scientific support underlying the intensive clinical experience and currently is suggesting ways of using ionizing radiations more effectively, such as modified fractionation schedules relating to cell cycle kinetics and the use of drugs and chemicals as modifiers of radiation response and normal tissue reaction. The radiation therapy clinic has provided the patient stratum on which the acute and chronic effects of irradiation have been assessed, and the patterns of treatment success and failure identified. The radiation therapist has shared with the surgeon and medical oncologist the responsibility for clarifying the natural history of a large number of human neoplasms, and through such clarifications, has developed more effective treatment strategies. Several examples of this include the improved results in the treatment of Hodgkin's disease, squamous cell carcinoma of the cervix, seminoma, and epithelial neoplasms of the upper aerodigestive tract

  15. [Cardiac effects of radiation therapy].

    Science.gov (United States)

    Tuohinen, Suvi; Turpeinen, Anu; Skyttä, Tanja; Kellokumpu-Lehtinen, Pirkko-Liisa

    2015-01-01

    Because of increased life-expentancy cancer patients having undergone radiation therapy nowadays live longer, and late-appearing adverse effects are therefore playing a more significant role. Radiation therapy given to the chest is known to approximately double the risk of heart disease, the cumulative total radiation dose being the most important risk-increasing factor. The most significant adverse effects appear only years after the treatment. The mortality from late manifestations reduces the total benefit of radiation therapy. Patients with radiation therapy due to a cancer of the left breast or Hodgkin's lymphoma are particularly susceptible to cardiac effects. A safe radiation dose is not known.

  16. Radiation therapy for digestive tumors

    International Nuclear Information System (INIS)

    Piedbois, P.; Levy, E.; Thirion, P.; Martin, L.; Calitchi, E.; Otmezguine, Y.; Le Bourgeois, J.P.

    1995-01-01

    This brief review of radiation therapy of digestive tumors in 1994 seeks to provide practical answers to the most commonly asked questions: What is the place of radiation therapy versus chemotherapy for the treatment of these patients ? What are the approved indications of radiation therapy and which avenues of research are being explored ? Radiation therapy is used in over two-thirds of patients referred to an oncology department for a gastrointestinal tract tumor. The main indications are reviewed: cancer of the rectum and anal canal and, to a lesser extent, cancer of the esophagus and pancreas. The main focuses of current research include radiation therapy-chemotherapy combinations, intraoperative radiation therapy, and radiation therapy of hepatobiliary tumors. (authors). 23 refs., 1 fig

  17. Computer-aided beam arrangement based on similar cases in radiation treatment-planning databases for stereotactic lung radiation therapy

    International Nuclear Information System (INIS)

    Magome, Taiki; Shioyama, Yoshiyuki; Arimura, Hidetaka

    2013-01-01

    The purpose of this study was to develop a computer-aided method for determination of beam arrangements based on similar cases in a radiotherapy treatment-planning database for stereotactic lung radiation therapy. Similar-case-based beam arrangements were automatically determined based on the following two steps. First, the five most similar cases were searched, based on geometrical features related to the location, size and shape of the planning target volume, lung and spinal cord. Second, five beam arrangements of an objective case were automatically determined by registering five similar cases with the objective case, with respect to lung regions, by means of a linear registration technique. For evaluation of the beam arrangements five treatment plans were manually created by applying the beam arrangements determined in the second step to the objective case. The most usable beam arrangement was selected by sorting the five treatment plans based on eight plan evaluation indices, including the D95, mean lung dose and spinal cord maximum dose. We applied the proposed method to 10 test cases, by using an RTP database of 81 cases with lung cancer, and compared the eight plan evaluation indices between the original treatment plan and the corresponding most usable similar-case-based treatment plan. As a result, the proposed method may provide usable beam arrangements, which have no statistically significant differences from the original beam arrangements (P>0.05) in terms of the eight plan evaluation indices. Therefore, the proposed method could be employed as an educational tool for less experienced treatment planners. (author)

  18. Technical advances in radiation therapy

    International Nuclear Information System (INIS)

    Sause, W.T.

    1986-01-01

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

  19. Long term results of primary radiation therapy for squamous cancer of the base of tongue

    International Nuclear Information System (INIS)

    Harrison, LB; Lee, H; Kraus, DH; Zelefsky, M; Strong, EW; Pfister, DG; Raben, A; Shah, J; White, C; Carper, E; Portenoy, R

    1996-01-01

    From 1981-1995, 68 patients with primary squamous cell cancer of the base of tongue were managed with primary radiation therapy, with neck dissection added for those who presented with palpable lymph node metastases. Ages ranged from 35-77 (median 55). There were 59 males and 9 females. T Stage was: T1-17, T2-32, T3-17, T4-2. Fifty-eight patients (85%) presented with nodal metastases. Treatment generally involved external beam radiation (EBRT) to the primary site and upper neck (54 Gy), low neck (50 Gy), additional EBRT to area of nodal involvement to 60 Gy, followed (2-4 weeks later) by brachytherapy boost (20-30 Gy) to the base of tongue using Iridium-192. The implant was done at the same anesthesia as the neck dissection, and all patients had temporary tracheostomy. Follow-up ranges from 1-151 months (median 36 months). Nine patients received neo-adjuvant chemotherapy. Actuarial 5 and 10-year local control is 88% and 88%, regional control is 96% and 96%, distant metastasis free survival is 91% and 76%, disease free survival is 80% and 67%, and overall survival is 86% and 52%, respectively. After EBRT, 78% of dissected necks were pathologically negative. Complications occurred in 16%. A detailed quality of life (QOL) assessment has been completed on the first 36 patients with a minimum follow-up of 3 years, and median follow-up of 5 years. This included a Performance Status Assessment, socio-demographic and economic questionnaire, a multidimensional QOL assessment measuring emotional, physical, social and functional well-being, and the Memorial Symptom Assessment Scale. This data will be presented. The overwhelming majority of patients were able to maintain their pre-diagnosis earning potential, employment status, speaking ability and ability to eat in public. However, a variety of symptoms such as xerostomia, swallowing difficulty, decreased energy, changes in taste and dietary restrictions were observed. Our data shows that primary radiation therapy produces

  20. SU-E-T-300: Dosimetric Comparision of 4D Radiation Therapy and 3D Radiation Therapy for the Liver Tumor Based On 4D Medical Image

    Energy Technology Data Exchange (ETDEWEB)

    Ma, C; Yin, Y [Shandong Tumor Hospital, Jinan, Shandong Provice (China)

    2015-06-15

    Purpose: The purpose of this work was to determine the dosimetric benefit to normal tissues by tracking liver tumor dose in four dimensional radiation therapy (4DRT) on ten phases of four dimensional computer tomagraphy(4DCT) images. Methods: Target tracking each phase with the beam aperture for ten liver cancer patients were converted to cumulative plan and compared to the 3D plan with a merged target volume based on 4DCT image in radiation treatment planning system (TPS). The change in normal tissue dose was evaluated in the plan by using the parameters V5, V10, V15, V20,V25, V30, V35 and V40 (volumes receiving 5, 10, 15, 20, 25, 30, 35 and 40Gy, respectively) in the dose-volume histogram for the liver; mean dose for the following structures: liver, left kidney and right kidney; and maximum dose for the following structures: bowel, duodenum, esophagus, stomach and heart. Results: There was significant difference between 4D PTV(average 115.71cm3 )and ITV(169.86 cm3). When the planning objective is 95% volume of PTV covered by the prescription dose, the mean dose for the liver, left kidney and right kidney have an average decrease 23.13%, 49.51%, and 54.38%, respectively. The maximum dose for bowel, duodenum,esophagus, stomach and heart have an average decrease 16.77%, 28.07%, 24.28%, 4.89%, and 4.45%, respectively. Compared to 3D RT, radiation volume for the liver V5, V10, V15, V20, V25, V30, V35 and V40 by using the 4D plans have a significant decrease(P≤0.05). Conclusion: The 4D plan method creates plans that permit better sparing of the normal structures than the commonly used ITV method, which delivers the same dosimetric effects to the target.

  1. [Radiation therapy for malignant tumors].

    Science.gov (United States)

    Murakami, Shumei; Konishi, Koji

    2008-04-01

    Radiation therapy uses ionizing radiation to kill cancer cells and shrink tumors, with consideration to minimize harmful damages to health tissues. About 30% of all people with cancer are treated with radiation therapy, either alone or in combination with chemotherapy. Radiation therapy may be internal or external. In brachytheraphy as the internal radiation therapy the radioisotope is implanted into or near the tumor by tubes as the container. And it is often used for patients with the tongue cancer. External radiation, the type most often used, comes from a machine outside the body. It is usually used for shrinking tumors with bony invasions such as gingival cancer and improving the pain in patients with bony metastasis. For the primary bone tumor the radiation therapy is not always used because the radiosensitivity of the almost primary bone tumor is low.

  2. Ototoxicity After Intensity-Modulated Radiation Therapy and Cisplatin-Based Chemotherapy in Children With Medulloblastoma

    International Nuclear Information System (INIS)

    Paulino, Arnold C.; Lobo, Mark; Teh, Bin S.; Okcu, M. Fatih; South, Michael; Butler, E. Brian; Su, Jack; Chintagumpala, Murali

    2010-01-01

    Purpose: To report the incidence of Pediatric Oncology Group (POG) Grade 3 or 4 ototoxicity in a cohort of patients treated with craniospinal irradiation (CSI) followed by posterior fossa (PF) and/or tumor bed (TB) boost using intensity-modulated radiation therapy (IMRT). Methods and Materials: From 1998 to 2006, 44 patients with medulloblastoma were treated with CSI followed by IMRT to the PF and/or TB and cisplatin-based chemotherapy. Patients with standard-risk disease were treated with 18 to 23.4 Gy CSI followed by either a (1) PF boost to 36 Gy and TB boost to 54 to 55.8 Gy or (2) TB boost to 55.8 Gy. Patients with high-risk disease received 36 to 39.6 Gy CSI followed by a (1) PF boost to 54 to 55.8 Gy, (2) PF boost to 45 Gy and TB boost to 55.8 Gy, or (3) TB boost to 55.8 Gy. Median audiogram follow-up was 41 months (range, 11-92.4 months). Results: POG Grade Ototoxicity 0, 1, 2, 3. and 4 was found in 29, 32, 11, 13. and 3 ears. respectively, with POG Grade 3 or 4 accounting for 18.2% of cases. There was a statistically significant difference in mean radiation dose (D mean ) cochlea according to degree of ototoxicity, with D mean cochlea increasing with severity of hearing loss (p = 0.027). Conclusions: Severe ototoxicity was seen in 18.2% of ears in children treated with IMRT boost and cisplatin-based chemotherapy. Increasing dose to the cochlea was associated with increasing severity of hearing loss.

  3. Radiation therapy for prostate cancer

    International Nuclear Information System (INIS)

    Nakamura, Katsumasa

    2001-01-01

    In Japan, where the mortality rate of prostate cancer is lower than in Western countries, radical prostatectomy or hormonal therapy has been applied more frequently than radiation therapy. However, the number of patients with prostate cancer has been increasing recently and the importance of radiation therapy has rapidly been recognized. Although there have been no randomized trials, results from several institutions in Western countries suggest that similar results of cancer control are achieved with either radiation therapy or radical prostatectomy. For higher-risk cases, conformal high-dose therapy or adjuvant hormonal therapy is more appropriate. In this article, the results of radiation therapy for prostate cancer were reviewed, with a view to the appropriate choice of therapy in Japan. (author)

  4. Definitive radiation therapy in locally advanced non-small cell lung cancer: Executive summary of an American Society for Radiation Oncology (ASTRO) evidence-based clinical practice guideline.

    Science.gov (United States)

    Rodrigues, George; Choy, Hak; Bradley, Jeffrey; Rosenzweig, Kenneth E; Bogart, Jeffrey; Curran, Walter J; Gore, Elizabeth; Langer, Corey; Louie, Alexander V; Lutz, Stephen; Machtay, Mitchell; Puri, Varun; Werner-Wasik, Maria; Videtic, Gregory M M

    2015-01-01

    To provide guidance to physicians and patients with regard to the use of definitive external beam radiation therapy (RT) in locally advanced non-small cell lung cancer (LA NSCLC) based on available medical evidence complemented by consensus-based expert opinion. A panel authorized by the American Society for Radiation Oncology (ASTRO) Board of Directors and Guidelines Subcommittee conducted 3 systematic reviews on the following topics: (1) ideal radical RT dose fractionation for RT alone; (2) ideal radical RT dose fractionation for chemoradiation; and (3) ideal timing of radical radiation therapy with systemic chemotherapy. Practice guideline recommendations were approved using an a priori-defined consensus-building methodology supported by ASTRO and approved tools for the grading of evidence quality and the strength of guideline recommendations. For patients managed by RT alone, a minimum dose of 60 Gy of RT is recommended. Dose escalation beyond 60 Gy in the context of combined modality concurrent chemoradiation has not been found to be associated with any clinical benefits. In the context of combined modality therapy, chemotherapy and radiation should ideally be given concurrently to maximize survival, local control, and disease response rate. A consensus and evidence-based clinical practice guideline for the definitive radiotherapeutic management of LA NSCLC has been created that addresses 3 important questions. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  5. Atlas-based deformable image registration for MRI-guided prostate radiation therapy

    International Nuclear Information System (INIS)

    Dowling, J.; Fripp, J.; Salvado, O.; Lambert, J.; Denham, J.W.; Capp, A.; Grer, P.B.; Parker, J.

    2010-01-01

    Full text: To develop atlas-based deformable image registration methods to automatically segment organs and map electron densities to pelvic MRI scans for MRI-guided radiation therapy. Methods An MRT pelvic atlas and corresponding CT atlas were developed based on whole pelvic T 2 MRI scans and CT scans for 39 patients. Expert manual segmentations on both MRI and CT scans were obtained. The atlas was deformably registered to the individual patient MRI scans for automatic prostate, rectum, bladder and bone segmentation. These were compared to the manual segmentations using the Dice overlap coefficient. The same deformation vectors were then applied to the CT-atlas to produce pseudo-CT scans that correspond to the patient MRI scan anatomy but are populated with Hounsfield units. The original patient plan was recalculated on the pseudo-CT and compared to the original CT plan and bulk density plans on the MRI scans. Results Dice coefficient results were high (>0.8) for bone and prostate but lower (<0.7) for bladder and rectum which exhibit greater changes in shape and volume. Doses calculated on pseudo-CT scans were within 3% of original patient plans. Two sources of discrepancy were found; MR anatomy differences from CT due to patient setup differences at the MR scanner. and Hounsfield unit differences for bone in the pseudo-CT from original CT. Patient setup will be adressed with a

  6. An Ensemble Approach to Knowledge-Based Intensity-Modulated Radiation Therapy Planning

    Directory of Open Access Journals (Sweden)

    Jiahan Zhang

    2018-03-01

    Full Text Available Knowledge-based planning (KBP utilizes experienced planners’ knowledge embedded in prior plans to estimate optimal achievable dose volume histogram (DVH of new cases. In the regression-based KBP framework, previously planned patients’ anatomical features and DVHs are extracted, and prior knowledge is summarized as the regression coefficients that transform features to organ-at-risk DVH predictions. In our study, we find that in different settings, different regression methods work better. To improve the robustness of KBP models, we propose an ensemble method that combines the strengths of various linear regression models, including stepwise, lasso, elastic net, and ridge regression. In the ensemble approach, we first obtain individual model prediction metadata using in-training-set leave-one-out cross validation. A constrained optimization is subsequently performed to decide individual model weights. The metadata is also used to filter out impactful training set outliers. We evaluate our method on a fresh set of retrospectively retrieved anonymized prostate intensity-modulated radiation therapy (IMRT cases and head and neck IMRT cases. The proposed approach is more robust against small training set size, wrongly labeled cases, and dosimetric inferior plans, compared with other individual models. In summary, we believe the improved robustness makes the proposed method more suitable for clinical settings than individual models.

  7. Radiation Therapy and Hearing Loss

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  8. Smart Radiation Therapy Biomaterials.

    Science.gov (United States)

    Ngwa, Wilfred; Boateng, Francis; Kumar, Rajiv; Irvine, Darrell J; Formenti, Silvia; Ngoma, Twalib; Herskind, Carsten; Veldwijk, Marlon R; Hildenbrand, Georg Lars; Hausmann, Michael; Wenz, Frederik; Hesser, Juergen

    2017-03-01

    Radiation therapy (RT) is a crucial component of cancer care, used in the treatment of over 50% of cancer patients. Patients undergoing image guided RT or brachytherapy routinely have inert RT biomaterials implanted into their tumors. The single function of these RT biomaterials is to ensure geometric accuracy during treatment. Recent studies have proposed that the inert biomaterials could be upgraded to "smart" RT biomaterials, designed to do more than 1 function. Such smart biomaterials include next-generation fiducial markers, brachytherapy spacers, and balloon applicators, designed to respond to stimuli and perform additional desirable functions like controlled delivery of therapy-enhancing payloads directly into the tumor subvolume while minimizing normal tissue toxicities. More broadly, smart RT biomaterials may include functionalized nanoparticles that can be activated to boost RT efficacy. This work reviews the rationale for smart RT biomaterials, the state of the art in this emerging cross-disciplinary research area, challenges and opportunities for further research and development, and a purview of potential clinical applications. Applications covered include using smart RT biomaterials for boosting cancer therapy with minimal side effects, combining RT with immunotherapy or chemotherapy, reducing treatment time or health care costs, and other incipient applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Accuracy of UTE-MRI-based patient setup for brain cancer radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yingli; Cao, Minsong; Kaprealian, Tania; Sheng, Ke; Gao, Yu; Gomez, Caitlin; Santhanam, Anand; Tenn, Stephen; Agazaryan, Nzhde; Low, Daniel A. [Department of Radiation Oncology, University of California, Los Angeles, California 90095 (United States); Han, Fei; Hu, Peng, E-mail: penghu@mednet.ucla.edu [Department of Radiological Sciences, University of California, Los Angeles, California 90095 (United States)

    2016-01-15

    Purpose: Radiation therapy simulations solely based on MRI have advantages compared to CT-based approaches. One feature readily available from computed tomography (CT) that would need to be reproduced with MR is the ability to compute digitally reconstructed radiographs (DRRs) for comparison against on-board radiographs commonly used for patient positioning. In this study, the authors generate MR-based bone images using a single ultrashort echo time (UTE) pulse sequence and quantify their 3D and 2D image registration accuracy to CT and radiographic images for treatments in the cranium. Methods: Seven brain cancer patients were scanned at 1.5 T using a radial UTE sequence. The sequence acquired two images at two different echo times. The two images were processed using an in-house software to generate the UTE bone images. The resultant bone images were rigidly registered to simulation CT data and the registration error was determined using manually annotated landmarks as references. DRRs were created based on UTE-MRI and registered to simulated on-board images (OBIs) and actual clinical 2D oblique images from ExacTrac™. Results: UTE-MRI resulted in well visualized cranial, facial, and vertebral bones that quantitatively matched the bones in the CT images with geometric measurement errors of less than 1 mm. The registration error between DRRs generated from 3D UTE-MRI and the simulated 2D OBIs or the clinical oblique x-ray images was also less than 1 mm for all patients. Conclusions: UTE-MRI-based DRRs appear to be promising for daily patient setup of brain cancer radiotherapy with kV on-board imaging.

  10. Chemotherapy and molecular target therapy combined with radiation therapy

    International Nuclear Information System (INIS)

    Akimoto, Tetsuo

    2012-01-01

    Combined chemotherapy and radiation therapy has been established as standard treatment approach for locally advanced head and neck cancer, esophageal cancer and so on through randomized clinical trials. However, radiation-related morbidity such as acute toxicity also increased as treatment intensity has increased. In underlining mechanism for enhancement of normal tissue reaction in chemo-radiation therapy, chemotherapy enhanced radiosensitivity of normal tissues in addition to cancer cells. Molecular target-based drugs combined with radiation therapy have been expected as promising approach that makes it possible to achieve cancer-specific enhancement of radiosensitivity, and clinical trials using combined modalities have been performed to evaluate the feasibility and efficacy of this approach. In order to obtain maximum radiotherapeutic gain, a detailed understanding of the mechanism underlying the interaction between radiation and Molecular target-based drugs is indispensable. Among molecular target-based drugs, inhibitors targeting epidermal growth factor receptor (EGFR) and its signal transduction pathways have been vigorously investigated, and mechanisms regarding the radiosensitizing effect have been getting clear. In addition, the results of randomized clinical trials demonstrated that radiation therapy combined with cetuximab resulted in improvement of overall and disease-specific survival rate compared with radiation therapy in locally advanced head and neck cancer. In this review, clinical usefulness of chemo-radiation therapy and potential molecular targets for potentiation of radiation-induced cell killing are summarized. (author)

  11. Development of a software based automatic exposure control system for use in image guided radiation therapy

    Science.gov (United States)

    Morton, Daniel R.

    Modern image guided radiation therapy involves the use of an isocentrically mounted imaging system to take radiographs of a patient's position before the start of each treatment. Image guidance helps to minimize errors associated with a patients setup, but the radiation dose received by patients from imaging must be managed to ensure no additional risks. The Varian On-Board Imager (OBI) (Varian Medical Systems, Inc., Palo Alto, CA) does not have an automatic exposure control system and therefore requires exposure factors to be manually selected. Without patient specific exposure factors, images may become saturated and require multiple unnecessary exposures. A software based automatic exposure control system has been developed to predict optimal, patient specific exposure factors. The OBI system was modelled in terms of the x-ray tube output and detector response in order to calculate the level of detector saturation for any exposure situation. Digitally reconstructed radiographs are produced via ray-tracing through the patients' volumetric datasets that are acquired for treatment planning. The ray-trace determines the attenuation of the patient and subsequent x-ray spectra incident on the imaging detector. The resulting spectra are used in the detector response model to determine the exposure levels required to minimize detector saturation. Images calculated for various phantoms showed good agreement with the images that were acquired on the OBI. Overall, regions of detector saturation were accurately predicted and the detector response for non-saturated regions in images of an anthropomorphic phantom were calculated to generally be within 5 to 10 % of the measured values. Calculations were performed on patient data and found similar results as the phantom images, with the calculated images being able to determine detector saturation with close agreement to images that were acquired during treatment. Overall, it was shown that the system model and calculation

  12. Radiation Therapy: Professions in Radiation Therapy

    Science.gov (United States)

    ... measurements of radiation beam characteristics and do other safety tests on a regular basis. Therapeutic medical physicists have doctorates or master's degrees and have completed four years of college, two to four years of graduate school and typically one to two years of clinical ...

  13. The physics of radiation therapy

    CERN Document Server

    Khan, Faiz M

    2009-01-01

    Dr. Khan's classic textbook on radiation oncology physics is now in its thoroughly revised and updated Fourth Edition. It provides the entire radiation therapy team—radiation oncologists, medical physicists, dosimetrists, and radiation therapists—with a thorough understanding of the physics and practical clinical applications of advanced radiation therapy technologies, including 3D-CRT, stereotactic radiotherapy, HDR, IMRT, IGRT, and proton beam therapy. These technologies are discussed along with the physical concepts underlying treatment planning, treatment delivery, and dosimetry. This Fourth Edition includes brand-new chapters on image-guided radiation therapy (IGRT) and proton beam therapy. Other chapters have been revised to incorporate the most recent developments in the field. This edition also features more than 100 full-color illustrations throughout.

  14. Job satisfaction among radiation therapy educators.

    Science.gov (United States)

    Swafford, Larry G; Legg, Jeffrey S

    2007-01-01

    Job satisfaction is one of the most consistent variables related to employee retention and is especially relevant considering the shortage of radiation therapists and radiation therapy educators in the United States. To investigate job satisfaction levels among radiation therapy educators certified by the American Registry of Radiologic Technologists and employed in programs accredited by the Joint Review Committee on Education in Radiologic Technology. The long form of the Minnesota Satisfaction Questionnaire (MSQ) was mailed to 158 radiation therapy educators to measure job satisfaction. Overall job satisfaction and subscales were calculated based on MSQ methodology. A total of 90 usable surveys were returned for a 56.9% response rate. With a "general satisfaction" score of 69.64, radiation therapy educators ranked in the lowest 25th percentile of the nondisabled norm scale for job satisfaction. Respondents reported higher degrees of job satisfaction on the moral values, social service and achievement subscales. Lower job satisfaction levels were associated with the company policies and practices, advancement and compensation subscales. Radiation therapy educators report low job satisfaction. Educational institutions must tailor recruitment and retention efforts to better reflect the positive aspects of being a radiation therapy educator. Furthermore, improving retention and recruitment efforts might help offset the current shortages of radiation therapy educators and, ultimately, clinical radiation therapists.

  15. Comparison of volumetric modulated arc therapy and intensity modulated radiation therapy for whole brain hippocampal sparing treatment plans based on radiobiological modeling

    Directory of Open Access Journals (Sweden)

    Ethan Kendall

    2018-01-01

    Full Text Available Introduction: In this article, we report the results of our investigation on comparison of radiobiological aspects of treatment plans with linear accelerator-based intensity-modulated radiation therapy and volumetric-modulated arc therapy for patients having hippocampal avoidance whole-brain radiation therapy. Materials and Methods: In this retrospective study using the dose-volume histogram, we calculated and compared biophysical indices of equivalent uniform dose, tumor control probability, and normal tissue complication probability (NTCP for 15 whole-brain radiotherapy patients. Results and Discussions: Dose-response models for tumors and critical structures were separated into two groups: mechanistic and empirical. Mechanistic models formulate mathematically with describable relationships while empirical models fit data through empirical observations to appropriately determine parameters giving results agreeable to those given by mechanistic models. Conclusions: Techniques applied in this manuscript could be applied to any other organs or types of cancer to evaluate treatment plans based on radiobiological modeling.

  16. Basic physics of radiation therapy

    International Nuclear Information System (INIS)

    Selman, J.

    1976-01-01

    The subject is discussed under the following chapter headings: simple mathematics gradiation therapy; matter and energy; the nature of radiation;reactions between radiation and matter; x-ray production and control; high-energy therapy units and particle accelerators; quantity of x rays and γ rays; x-ray quality; dosage in x-ray and γ-ray therapy; therapy planning; radioactivity and nuclear physics; implant therapy with radium, radon, and artificial radionuclides; surface therapy with β particles; medical use of radionuclides; radiobiology; radiotherapy with heavy particles; and protection in radiotherapy-health physics

  17. A novel miRNA-based predictive model for biochemical failure following post-prostatectomy salvage radiation therapy.

    Directory of Open Access Journals (Sweden)

    Erica Hlavin Bell

    Full Text Available To develop a microRNA (miRNA-based predictive model for prostate cancer patients of 1 time to biochemical recurrence after radical prostatectomy and 2 biochemical recurrence after salvage radiation therapy following documented biochemical disease progression post-radical prostatectomy.Forty three patients who had undergone salvage radiation therapy following biochemical failure after radical prostatectomy with greater than 4 years of follow-up data were identified. Formalin-fixed, paraffin-embedded tissue blocks were collected for all patients and total RNA was isolated from 1mm cores enriched for tumor (>70%. Eight hundred miRNAs were analyzed simultaneously using the nCounter human miRNA v2 assay (NanoString Technologies; Seattle, WA. Univariate and multivariate Cox proportion hazards regression models as well as receiver operating characteristics were used to identify statistically significant miRNAs that were predictive of biochemical recurrence.Eighty eight miRNAs were identified to be significantly (p36 months. Nine miRNAs were identified to be significantly (p<0.05 associated by multivariate analysis with biochemical failure after salvage radiation therapy. A new predictive model for biochemical recurrence after salvage radiation therapy was developed; this model consisted of miR-4516 and miR-601 together with, Gleason score, and lymph node status. The area under the ROC curve (AUC was improved to 0.83 compared to that of 0.66 for Gleason score and lymph node status alone.miRNA signatures can distinguish patients who fail soon after radical prostatectomy versus late failures, giving insight into which patients may need adjuvant therapy. Notably, two novel miRNAs (miR-4516 and miR-601 were identified that significantly improve prediction of biochemical failure post-salvage radiation therapy compared to clinico-histopathological factors, supporting the use of miRNAs within clinically used predictive models. Both findings warrant further

  18. Radiation therapy in palliative care

    International Nuclear Information System (INIS)

    Ikushima, Hitoshi; Nishitani, Hiromu

    2005-01-01

    Radiation therapy is a valuable treatment for palliation of local symptoms with consistently high response rates in the relief and control of bone pain, neurological symptom, obstructive symptoms, and tumor hemorrhage. Over than 80% of patients who developed bone metastasis and superior vena cava syndrome obtained symptom relief by radiation therapy. Radiation therapy is also well established as an effective treatment for brain metastasis, improving symptoms and preventing progressive neurological deficits, and recently stereotactic irradiation had became a alternative treatment of surgery for small metastatic brain tumors. Both radiation therapy and surgery are effective in the initial treatment of malignant spinal cord compression syndrome, and no advantages of surgery over radiation therapy has been demonstrated in published series when patients have a previously conformed diagnosis of malignant disease and no evidence of vertebral collapse. The outcome of treatment depends primarily upon the speed of diagnosis and neurological status at initiation of treatment. It is very important to start radiation therapy before patient become non-ambulant. Low irradiation dose and short treatment period of palliative radiation therapy can minimize disruption and acute morbidity for the patients with advanced cancer with enabling control of symptoms and palliative radiation therapy is applicable to the patient even in poor general condition. (author)

  19. Frame-Based Immobilization and Targeting for Stereotactic Body Radiation Therapy

    International Nuclear Information System (INIS)

    Murray, Bryan C.; Forster, Kenneth; Timmerman, Robert

    2007-01-01

    Frame-based stereotactic body radiation therapy (SBRT), such as that conducted with Elekta's Stereotactic Body Frame, can provide an extra measure of precision in the delivery of radiation to extracranial targets, and facilitates secure patient immobilization. In this paper, we review the steps involved in optimal use of an extra-cranial immobilization device for SBRT treatments. Our approach to using frame-based SBRT consists of 4 steps: patient immobilization, tumor and organ motion control, treatment/planning correlation, and daily targeting with pretreatment quality assurance. Patient immobilization was achieved with the Vac-Loc bag, which uses styrofoam beads to conform to the patient's shape comfortably within the body frame. Organ and motion control was assessed under fluoroscopy and controlled via a frame-mounted abdominal pressure plate. The compression screw was tightened until the diaphragmatic excursion range was < 1 cm. Treatment planning was performed using the Philips Pinnacle 6.2b system. In this treatment process, a 20 to 30 noncoplanar beam arrangement was initially selected and an inverse beam weight optimization algorithm was applied. Those beams with low beam weights were removed, leaving a manageable number of beams for treatment delivery. After planning, daily targeting using computed tomography (CT) to verify x-, y-, and z-coordinates of the treatment isocenter were used as a measure of quality assurance. We found our daily setup variation typically averaged < 5 mm in all directions, which is comparable to other published studies on Stereotactic Body Frame. Treatment time ranged from 30 to 45 minutes. Results demonstrate that patients have experienced high rates of local control with acceptable rates of severe side effects-by virtue of the tightly constrained treatment fields. The body frame facilitated comfortable patient positioning and quality assurance checks of the tumor, in relation to another set of independent set of coordinates

  20. Multivariate regression approaches for surrogate-based diffeomorphic estimation of respiratory motion in radiation therapy

    Science.gov (United States)

    Wilms, M.; Werner, R.; Ehrhardt, J.; Schmidt-Richberg, A.; Schlemmer, H.-P.; Handels, H.

    2014-03-01

    Breathing-induced location uncertainties of internal structures are still a relevant issue in the radiation therapy of thoracic and abdominal tumours. Motion compensation approaches like gating or tumour tracking are usually driven by low-dimensional breathing signals, which are acquired in real-time during the treatment. These signals are only surrogates of the internal motion of target structures and organs at risk, and, consequently, appropriate models are needed to establish correspondence between the acquired signals and the sought internal motion patterns. In this work, we present a diffeomorphic framework for correspondence modelling based on the Log-Euclidean framework and multivariate regression. Within the framework, we systematically compare standard and subspace regression approaches (principal component regression, partial least squares, canonical correlation analysis) for different types of common breathing signals (1D: spirometry, abdominal belt, diaphragm tracking; multi-dimensional: skin surface tracking). Experiments are based on 4D CT and 4D MRI data sets and cover intra- and inter-cycle as well as intra- and inter-session motion variations. Only small differences in internal motion estimation accuracy are observed between the 1D surrogates. Increasing the surrogate dimensionality, however, improved the accuracy significantly; this is shown for both 2D signals, which consist of a common 1D signal and its time derivative, and high-dimensional signals containing the motion of many skin surface points. Eventually, comparing the standard and subspace regression variants when applied to the high-dimensional breathing signals, only small differences in terms of motion estimation accuracy are found.

  1. Optimization of radiation therapy

    International Nuclear Information System (INIS)

    Ohtsubo, Masaaki

    1990-01-01

    In radiotherapy, dose optimization is to give adequate dose uniformly over target volume and minimize the dose to normal and adjacent critical organs. Therefore, it is necessary to analyze dose distribution in detail. This paper presents a method for quantitatively assessing treatment planning by analysis of dose distribution. For this purpose, several parameters were introduced, such as D T, min (minimum target absorbed dose), NUF (nonuniformity factor), volume rate of damaged lung and spinal cord, R T/T (ratio of target volume to treatment volume), LE (local efficiency), integral dose, etc. And some criteria were made using these parameters, and were applied to evaluate various plans in external beam radiation therapy for lung and esophagus cancer. In these parameters, NUF was especially useful to obtain three-dimensional dose information of target volume, and value of NUF was in agreement with the information provided by dose volume histogram. AP-PA parallel opposed fields technique was inferior in D T,min and NUF. In lung cancer, there was no spinal cord injury in oblique parallel opposed fields technique, and this technique is particularly useful when target volume is in posterior. In these two techniques, R T/T was small and hot spots were frequently observed. R T/T was largest in oblique wedged two-fields technique, but this technique was inferior in D T, min and NUF. About D T, min and NUF, four fields technique was the best, but in this technique spinal cord complication often occurred in case that target volume was in the middle. In moving beam technique (360deg rotation or arc), integral dose is large, and the more target volume is in posterior, the more often spinal cord complication occurs. In esophageal cancer, three fields technique was the best to avoid spinal cord injury. It seems that this method is very useful for optimization in radiation treatment planning. (author)

  2. Cherenkoscopy based patient positioning validation and movement tracking during post-lumpectomy whole breast radiation therapy.

    Science.gov (United States)

    Zhang, Rongxiao; Andreozzi, Jacqueline M; Gladstone, David J; Hitchcock, Whitney L; Glaser, Adam K; Jiang, Shudong; Pogue, Brian W; Jarvis, Lesley A

    2015-01-07

    To investigate Cherenkov imaging (Cherenkoscopy) based patient positioning and movement tracking during external beam radiation therapy (EBRT). In a phase 1 clinical trial, including 12 patients undergoing post-lumpectomy whole breast irradiation, Cherenkov emission was imaged with a time-gated ICCD camera synchronized to the LINAC pulse output, during different fractions of the treatment. Patients were positioned with the aid of the AlignRT system in the beginning of each treatment session. Inter-fraction setup variation was studied by rigid image registrations between images acquired at individual treatments to the average image from all imaged treatment fractions. The amplitude of respiratory motion was calculated from the registration of each frame of Cherenkov images to the reference. A Canny edge detection algorithm was utilized to highlight the beam field edges and biological features provided by major blood vessels apparent in the images. Real-time Cherenkoscopy can monitor the treatment delivery, patient motion and alignment of the beam edge to the treatment region simultaneously. For all the imaged fractions, the patient positioning discrepancies were within our clinical tolerances (3 mm in shifts and 3 degree in pitch angle rotation), with 4.6% exceeding 3 mm but still within 4 mm in shifts. The average discrepancy of repetitive patient positioning was 1.22 mm in linear shift and 0.34 degrees in rotational pitch, consistent with the accuracy reported by the AlignRT system. The edge detection algorithm enhanced features such as field edges and blood vessels. Patient positioning discrepancies and respiratory motion retrieved from rigid image registration were consistent with the edge enhanced images. Besides positioning discrepancies caused by globally inaccurate setups, edge enhanced blood vessels indicate the existence of deformations within the treatment region, especially for large patients. Real-time Cherenkoscopy imaging during EBRT is a

  3. Temporal regularization of ultrasound-based liver motion estimation for image-guided radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    O’Shea, Tuathan P., E-mail: tuathan.oshea@icr.ac.uk; Bamber, Jeffrey C.; Harris, Emma J. [Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS foundation Trust, Sutton, London SM2 5PT (United Kingdom)

    2016-01-15

    Purpose: Ultrasound-based motion estimation is an expanding subfield of image-guided radiation therapy. Although ultrasound can detect tissue motion that is a fraction of a millimeter, its accuracy is variable. For controlling linear accelerator tracking and gating, ultrasound motion estimates must remain highly accurate throughout the imaging sequence. This study presents a temporal regularization method for correlation-based template matching which aims to improve the accuracy of motion estimates. Methods: Liver ultrasound sequences (15–23 Hz imaging rate, 2.5–5.5 min length) from ten healthy volunteers under free breathing were used. Anatomical features (blood vessels) in each sequence were manually annotated for comparison with normalized cross-correlation based template matching. Five sequences from a Siemens Acuson™ scanner were used for algorithm development (training set). Results from incremental tracking (IT) were compared with a temporal regularization method, which included a highly specific similarity metric and state observer, known as the α–β filter/similarity threshold (ABST). A further five sequences from an Elekta Clarity™ system were used for validation, without alteration of the tracking algorithm (validation set). Results: Overall, the ABST method produced marked improvements in vessel tracking accuracy. For the training set, the mean and 95th percentile (95%) errors (defined as the difference from manual annotations) were 1.6 and 1.4 mm, respectively (compared to 6.2 and 9.1 mm, respectively, for IT). For each sequence, the use of the state observer leads to improvement in the 95% error. For the validation set, the mean and 95% errors for the ABST method were 0.8 and 1.5 mm, respectively. Conclusions: Ultrasound-based motion estimation has potential to monitor liver translation over long time periods with high accuracy. Nonrigid motion (strain) and the quality of the ultrasound data are likely to have an impact on tracking

  4. A first generation compact microbeam radiation therapy system based on carbon nanotube X-ray technology

    International Nuclear Information System (INIS)

    Hadsell, M.; Shan, J.; Burk, L.; Zhang, J.; Chang, S.; Laganis, P.; Sprenger, F.; Zhang, L.; Yuan, H.; Lu, J.; Zhou, O.

    2013-01-01

    We have developed a compact microbeam radiation therapy device using carbon nanotube cathodes to create a linear array of narrow focal line segments on a tungsten anode and a custom collimator assembly to select a slice of the resulting wedge-shaped radiation pattern. Effective focal line width was measured to be 131 μm, resulting in a microbeam width of ∼300 μm. The instantaneous dose rate was projected to be 2 Gy/s at full-power. Peak to valley dose ratio was measured to be >17 when a 1.4 mm microbeam separation was employed. Finally, multiple microbeams were delivered to a mouse with beam paths verified through histology

  5. Respiratory gating based on internal electromagnetic motion monitoring during stereotactic liver radiation therapy: First results.

    Science.gov (United States)

    Poulsen, Per Rugaard; Worm, Esben Schjødt; Hansen, Rune; Larsen, Lars Peter; Grau, Cai; Høyer, Morten

    2015-01-01

    Intrafraction motion may compromise the target dose in stereotactic body radiation therapy (SBRT) of tumors in the liver. Respiratory gating can improve the treatment delivery, but gating based on an external surrogate signal may be inaccurate. This is the first paper reporting on respiratory gating based on internal electromagnetic monitoring during liver SBRT. Two patients with solitary liver metastases were treated with respiratory-gated SBRT guided by three implanted electromagnetic transponders. The treatment was delivered in end-exhale with beam-on when the centroid of the three transponders deviated less than 3 mm [left-right (LR) and anterior-posterior (AP) directions] and 4mm [cranio-caudal (CC)] from the planned position. For each treatment fraction, log files were used to determine the transponder motion during beam-on in the actual gated treatments and in simulated treatments without gating. The motion was used to reconstruct the dose to the clinical target volume (CTV) with and without gating. The reduction in D95 (minimum dose to 95% of the CTV) relative to the plan was calculated for both treatment courses. With gating the maximum course mean (standard deviation) geometrical error in any direction was 1.2 mm (1.8 mm). Without gating the course mean error would mainly increase for Patient 1 [to -2.8 mm (1.6 mm) (LR), 7.1 mm (5.8 mm) (CC), -2.6 mm (2.8mm) (AP)] due to a large systematic cranial baseline drift at each fraction. The errors without gating increased only slightly for Patient 2. The reduction in CTV D95 was 0.5% (gating) and 12.1% (non-gating) for Patient 1 and 0.3% (gating) and 1.7% (non-gating) for Patient 2. The mean duty cycle was 55%. Respiratory gating based on internal electromagnetic motion monitoring was performed for two liver SBRT patients. The gating added robustness to the dose delivery and ensured a high CTV dose even in the presence of large intrafraction motion.

  6. Radiation therapy in the neonate

    International Nuclear Information System (INIS)

    Littman, P.; D'Angio, G.J.

    1981-01-01

    Radiation therapy (RT) is frequently used in the management of children with cancer, but neonatal neoplasms are rare. Newborns represent 1.5% of the children with malignant diseases in the Tumor Registry at the Children's Hospital of Philadelphia over the last 30 years. Thus, occasionally the pediatrics radiation therapist must consider treating the very young infant. The specific radiation effects on growth and development must be weighed in reaching a therapeutic decision. All children are vulnerable to the late effects of radiation therapy, but the neonates may be more susceptible because of the immaturity of important organs such as the brain, lung, liver, kidney, and bone. In general, radiation therapy, should be avoided during the first several weeks of life because of the potential increased sensitivity of the liver and kidneys during that period. If radiation therapy is used at all during infancy, the benefits must be weighed against the possibility of significant late effects. Increasing knowledge of pediatric neoplasms has shown that some tumors (such as mesoblastic nephroma) require no treatment except for surgical excision; and other tumors, such as Stage IV-S neuroblastoma, may require very little treatment. In those tumors that require radiation therapy, the use of chemotherapy may allow reduction of the radiation dose. Furthermore, alterations of time-dose-fractionation schemes and careful attention to tumor volume with the use of special techniques, such as ''shrinking fields,'' may decrease the late adverse effects of treatment

  7. Radiation Therapy for Gynecologic Cancers

    Science.gov (United States)

    ... with some form of gynecologic cancer this year. Cancers of the uterus and cervix are most common gynecologic cancers treated ... detected or removed by surgery. Radiation therapy kills ... of the uterus and cervix, called a hysterectomy. The surgeon may ...

  8. Malignant mesothelioma following radiation therapy.

    Science.gov (United States)

    Hofmann, J; Mintzer, D; Warhol, M J

    1994-10-01

    Studies of the growing population of long-term survivors of cancer have led to increased recognition of the neoplastic complications of therapy. The causes of secondary malignancies are probably multifactorial, but radiation therapy and chemotherapy have certainly been implicated in the development of posttherapy neoplasia. A case of pleural mesothelioma after successful radiation therapy for Hodgkin's disease is described with a review of radiation-associated mesotheliomas reported in the literature. In Hodgkin's disease, patients may receive radiation, chemotherapy, or combined treatment; the most common secondary malignancy is acute nonlymphocytic leukemia while sarcomas are the second most common solid tumors. Although mesothelioma is an uncommon sarcoma, its occurrence has been documented numerous times after exposure to diagnostic or therapeutic radiation.

  9. Monte Carlo-based treatment planning system calculation engine for microbeam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Rovira, I.; Sempau, J.; Prezado, Y. [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, Barcelona E-08028 (Spain) and ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 rue Jules Horowitz B.P. 220, F-38043 Grenoble Cedex (France); Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, Barcelona E-08028 (Spain); Laboratoire Imagerie et modelisation en neurobiologie et cancerologie, UMR8165, Centre National de la Recherche Scientifique (CNRS), Universites Paris 7 et Paris 11, Bat 440., 15 rue Georges Clemenceau, F-91406 Orsay Cedex (France)

    2012-05-15

    Purpose: Microbeam radiation therapy (MRT) is a synchrotron radiotherapy technique that explores the limits of the dose-volume effect. Preclinical studies have shown that MRT irradiations (arrays of 25-75-{mu}m-wide microbeams spaced by 200-400 {mu}m) are able to eradicate highly aggressive animal tumor models while healthy tissue is preserved. These promising results have provided the basis for the forthcoming clinical trials at the ID17 Biomedical Beamline of the European Synchrotron Radiation Facility (ESRF). The first step includes irradiation of pets (cats and dogs) as a milestone before treatment of human patients. Within this context, accurate dose calculations are required. The distinct features of both beam generation and irradiation geometry in MRT with respect to conventional techniques require the development of a specific MRT treatment planning system (TPS). In particular, a Monte Carlo (MC)-based calculation engine for the MRT TPS has been developed in this work. Experimental verification in heterogeneous phantoms and optimization of the computation time have also been performed. Methods: The penelope/penEasy MC code was used to compute dose distributions from a realistic beam source model. Experimental verification was carried out by means of radiochromic films placed within heterogeneous slab-phantoms. Once validation was completed, dose computations in a virtual model of a patient, reconstructed from computed tomography (CT) images, were performed. To this end, decoupling of the CT image voxel grid (a few cubic millimeter volume) to the dose bin grid, which has micrometer dimensions in the transversal direction of the microbeams, was performed. Optimization of the simulation parameters, the use of variance-reduction (VR) techniques, and other methods, such as the parallelization of the simulations, were applied in order to speed up the dose computation. Results: Good agreement between MC simulations and experimental results was achieved, even at

  10. Radiation therapy after radical prostatectomy for prostate cancer: evaluation of complications and influence of radiation timing on outcomes in a large, population-based cohort.

    Directory of Open Access Journals (Sweden)

    Sarah E Hegarty

    Full Text Available To evaluate the influence of timing of salvage and adjuvant radiation therapy on outcomes after prostatectomy for prostate cancer.Using the Surveillance, Epidemiology, and End Results-Medicare linked database, we identified prostate cancer patients diagnosed during 1995-2007 who had one or more adverse pathological features after prostatectomy. The final cohort of 6,137 eligible patients included men who received prostatectomy alone (n = 4,509 or with adjuvant (n = 894 or salvage (n = 734 radiation therapy. Primary outcomes were genitourinary, gastrointestinal, and erectile dysfunction events and survival after treatment(s.Radiation therapy after prostatectomy was associated with higher rates of gastrointestinal and genitourinary events, but not erectile dysfunction. In adjusted models, earlier treatment with adjuvant radiation therapy was not associated with increased rates of genitourinary or erectile dysfunction events compared to delayed salvage radiation therapy. Early adjuvant radiation therapy was associated with lower rates of gastrointestinal events that salvage radiation therapy, with hazard ratios of 0.80 (95% CI, 0.67-0.95 for procedure-defined and 0.70 (95% CI, 0.59, 0.83 for diagnosis-defined events. There was no significant difference between ART and non-ART groups (SRT or RP alone for overall survival (HR = 1.13 95% CI = (0.96, 1.34 p = 0.148.Radiation therapy after prostatectomy is associated with increased rates of gastrointestinal and genitourinary events. However, earlier radiation therapy is not associated with higher rates of gastrointestinal, genitourinary or sexual events. These findings oppose the conventional belief that delaying radiation therapy reduces the risk of radiation-related complications.

  11. Care of the patient receiving radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yasko, J.M.

    1982-12-01

    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.

  12. Care of the patient receiving radiation therapy

    International Nuclear Information System (INIS)

    Yasko, J.M.

    1982-01-01

    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

  13. A Population-Based Comparative Effectiveness Study of Radiation Therapy Techniques in Stage III Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Jeremy P. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Murphy, James D. [Department of Radiation Medicine and Applied Science, University of California– San Diego, Moores Cancer Center, La Jolla, California (United States); Hanlon, Alexandra L. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); University of Pennsylvania School of Nursing, Philadelphia, Pennsylvania (United States); Le, Quynh-Thu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Loo, Billy W., E-mail: BWLoo@Stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Diehn, Maximilian, E-mail: diehn@Stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California (United States)

    2014-03-15

    Purpose: Concerns have been raised about the potential for worse treatment outcomes because of dosimetric inaccuracies related to tumor motion and increased toxicity caused by the spread of low-dose radiation to normal tissues in patients with locally advanced non-small cell lung cancer (NSCLC) treated with intensity modulated radiation therapy (IMRT). We therefore performed a population-based comparative effectiveness analysis of IMRT, conventional 3-dimensional conformal radiation therapy (3D-CRT), and 2-dimensional radiation therapy (2D-RT) in stage III NSCLC. Methods and Materials: We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare database to identify a cohort of patients diagnosed with stage III NSCLC from 2002 to 2009 treated with IMRT, 3D-CRT, or 2D-RT. Using Cox regression and propensity score matching, we compared survival and toxicities of these treatments. Results: The proportion of patients treated with IMRT increased from 2% in 2002 to 25% in 2009, and the use of 2D-RT decreased from 32% to 3%. In univariate analysis, IMRT was associated with improved overall survival (OS) (hazard ratio [HR] 0.90, P=.02) and cancer-specific survival (CSS) (HR 0.89, P=.02). After controlling for confounders, IMRT was associated with similar OS (HR 0.94, P=.23) and CSS (HR 0.94, P=.28) compared with 3D-CRT. Both techniques had superior OS compared with 2D-RT. IMRT was associated with similar toxicity risks on multivariate analysis compared with 3D-CRT. Propensity score matched model results were similar to those from adjusted models. Conclusions: In this population-based analysis, IMRT for stage III NSCLC was associated with similar OS and CSS and maintained similar toxicity risks compared with 3D-CRT.

  14. Partial breast radiation therapy - external beam

    Science.gov (United States)

    Carcinoma of the breast - partial radiation therapy; Partial external beam radiation - breast; Intensity-modulated radiation therapy - breast cancer; IMRT - breast cancer WBRT; Adjuvant partial breast - IMRT; APBI - IMRT; ...

  15. Radiation Therapy of Pituitary Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Park, Moon Baik; Hong, Seong Eong [Kyunghee University College of Medicine, Seoul (Korea, Republic of)

    1989-12-15

    Radiation treatment results were analyzed in a retrospective analysis of 47 patients with pituitary adenoma treated with radiation alone or combined with surgery from 1974 through 1987 at the Department of Therapeutic Radiology of Kyung Hee University. The 5-year overall survival rates for all patients was 80.4%. Radiation therapy was effective for improving visual symptoms and headache, but could not normalize amenorrhea and galactorrhoea. There was no difference of survival rate between radiation alone and combination with surgery. Prognostic factors such as age, sex, disease type, visual field, headache and surgical treatment were statistically no significant in survival rates of these patients.

  16. Radiation Therapy of Pituitary Tumors

    International Nuclear Information System (INIS)

    Park, Moon Baik; Hong, Seong Eong

    1989-01-01

    Radiation treatment results were analyzed in a retrospective analysis of 47 patients with pituitary adenoma treated with radiation alone or combined with surgery from 1974 through 1987 at the Department of Therapeutic Radiology of Kyung Hee University. The 5-year overall survival rates for all patients was 80.4%. Radiation therapy was effective for improving visual symptoms and headache, but could not normalize amenorrhea and galactorrhoea. There was no difference of survival rate between radiation alone and combination with surgery. Prognostic factors such as age, sex, disease type, visual field, headache and surgical treatment were statistically no significant in survival rates of these patients

  17. Study protocol for an approach based on diagnosis and therapy of cutaneous radiation induced lesions

    International Nuclear Information System (INIS)

    Di Giorgio, Marina; Vallerga, Maria B.; Radl, Analia; Portas, Mercedes

    2008-01-01

    Full text: In the frame of an agreement between the 'Hospital de Quemados del Gobierno de la Ciudad de Buenos Aires'-Burn Center- (a reference hospital of the Medical Radiological Emergency Response Network of Argentina) and the Nuclear Regulatory Authority, a research project for diagnostic and therapeutic approach of cutaneous radiation syndrome (CRS) is in progress. Sixty seven persons, which developed acute and/or late CRS, were included in this protocol from 1997 to 2007, treated with an equivalent therapeutic scheme and evaluated through clinical follow-up, serial photographic record and complementary tests (tele-thermography and high frequency ultrasonography). There exist individual variations that could condition the response to ionizing radiation (IR) in not only accidental but also planned exposures (such as radiotherapy and interventional radiology). Deficiencies in DNA repair mechanisms would be involved on hypersensitivity to deterministic effects of IR. Consequently, the characterization of DNA repair capacity in lymphocytes through cytokinesis blocked micronucleus (MN) and alkaline single-cell microgel electrophoresis (comet) assays could be suitable approaches to evaluate in vitro individual radiosensitivity. Under this context, individual radiosensitivity assessment was conducted in patients included in this research protocol that showed acute and/or late cutaneous reactions with grades 3 and 4 of the Toxicity Criteria of the Radiation Therapy Oncology Group and the European Organization for Research and Treatment of Cancer. DNA repair capacity was evaluated through MN and comet assay for initial damage and after specific times of repair (0-120 minutes). DNA damage and repair capacity were quantified by the Olive tail moment. Previous own studies have identified three subpopulations, characterized by the mean values of their repair mean half-time: healthy controls (2.6 ± 0.3 minutes), average-reactor cancer patients (4.7 ± 2.9 minutes) and over

  18. Advances in radiation therapy dosimetry

    Directory of Open Access Journals (Sweden)

    Paliwal Bhudatt

    2009-01-01

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

  19. National Cancer Data Base Analysis of Radiation Therapy Consolidation Modality for Cervical Cancer: The Impact of New Technological Advancements

    Energy Technology Data Exchange (ETDEWEB)

    Gill, Beant S. [Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Lin, Jeff F. [Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Krivak, Thomas C. [Department of Gynecologic Oncology, Western Pennsylvania Hospital, Pittsburgh, Pennsylvania (United States); Sukumvanich, Paniti; Laskey, Robin A.; Ross, Malcolm S.; Lesnock, Jamie L. [Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Beriwal, Sushil, E-mail: beriwals@upmc.edu [Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States)

    2014-12-01

    Purpose: To utilize the National Cancer Data Base to evaluate trends in brachytherapy and alternative radiation therapy utilization in the treatment of cervical cancer, to identify associations with outcomes between the various radiation therapy modalities. Methods and Materials: Patients with International Federation of Gynecology and Obstetrics stage IIB-IVA cervical cancer in the National Cancer Data Base who received treatment from January 2004 to December 2011 were analyzed. Overall survival was estimated by the Kaplan-Meier method. Univariate and multivariable analyses were performed to identify factors associated with type of boost radiation modality used and its impact on survival. Results: A total of 7654 patients had information regarding boost modality. A predominant proportion of patients were Caucasian (76.2%), had stage IIIB (48.9%) disease with squamous (82.0%) histology, were treated at academic/research centers (47.7%) in the South (34.8%), and lived 0 to 5 miles (27.9%) from the treating facility. A majority received brachytherapy (90.3%). From 2004 to 2011, brachytherapy use decreased from 96.7% to 86.1%, whereas intensity modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) use increased from 3.3% to 13.9% in the same period (P<.01). Factors associated with decreased brachytherapy utilization included older age, stage IVA disease, smaller tumor size, later year of diagnosis, lower-volume treatment centers, and facility type. After controlling for significant factors from survival analyses, IMRT or SBRT boost resulted in inferior overall survival (hazard ratio, 1.86; 95% confidence interval, 1.35-2.55; P<.01) as compared with brachytherapy. In fact, the survival detriment associated with IMRT or SBRT boost was stronger than that associated with excluding chemotherapy (hazard ratio, 1.61′ 95% confidence interval, 1.27-2.04′ P<.01). Conclusions: Consolidation brachytherapy is a critical treatment component for

  20. Radiation therapy of nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Nho, Y. J.; Cho, J. G.; Ahn, S. D.; Choi, E. K.; Kim, J. H.; Kang, O. C.; Chang, H. S.

    1997-01-01

    This is a retrospective study to evaluate the results of radiation therapy and prognostic factors influencing the results in nasopharyngeal carcinoma. From October 1989 to May 1996, 56 patients were treated for nasopharyngeal carcinoma at Department of Radiation Oncology. According to stage, patients were distributed as follows: stage I (2), II (13), III (11), IV (30). Twenty-eight patients were treated with radiation therapy and weekly CDDP. After external beam radiotherapy of 60Gy, 46 patients received boost dose with intracavitary radiation and 9 patients with 3D conformal therapy. One patient received boost dose with 2 dimensional photon beam therapy. The tumor dose ranged from 69.4Gy to 86.2Gy with median dose of 74.4Gy. The follow-up period ranged from 5 months to 92 months with a median of 34 months. Forty-seven patients achieved complete response and 8 patients showed partial response. One patient showed minimal response. Patterns of failure were as follows: locoregional recurrence (8) and distant metastasis (18). Among these patients, 2 patients failed locoregionally and distantly, The sites of distant metastasis were bone (8), lung (8) and liver (4). Five years survival rate was 67.2% and 5 years disease-free survival rate was 53.6%. KPS (P=0.005) and response of radiation therapy (P=0.0001) were significant prognostic factors for overall survival. KPS (P=0.02) and response of radiation therapy (P=0.005) were significant prognostic factors for disease-free survival. This retrospective study showed that distant metastasis was the predominant pattern of relapse in nasopharyngeal cancer. Neoadjuvant chemotherapy or weekly CDDP did not influence the distant metastasis-free survival. For advanced T stage, 3D conformal therapy provided an improved dose coverage compared to ICR. But further follow-up was needed in patients with 3D conformal therapy to assess the efficacy of this therapy. Development of techniques of radiation therapy to improve locoregional

  1. Radiation therapy in pseudotumour haemarthrosis

    Energy Technology Data Exchange (ETDEWEB)

    Lal, P.; Biswal, B.M.; Thulkar, S.; Patel, A.K.; Venkatesh, R.; Julka, P.K. [Institute Rotary Cancer Hospital, All India Institute of Medical Sciences, Ansari Nagar, New Delhi (India). Departments of Radiation Oncology, Radiodiagnosis and Haematology

    1998-11-01

    Total or partial deficiency of factor VIII and IX in the coagulation cascade leads to haemophilia. Haemophilia affecting weight-bearing joints gives a `pseudotumour` or haemarthrosis-like condition. Surgery and cryoprecipitate infusions have been the treatment for this condition. Radiocolloids and radiation therapy have been used with some benefit. One case of ankle pseudotumour which was treated by low-dose external beam radiation is presented here. Copyright (1998) Blackwell Science Pty Ltd 14 refs., 2 figs.

  2. Radiation therapy in pseudotumour haemarthrosis

    International Nuclear Information System (INIS)

    Lal, P.; Biswal, B.M.; Thulkar, S.; Patel, A.K.; Venkatesh, R.; Julka, P.K.

    1998-01-01

    Total or partial deficiency of factor VIII and IX in the coagulation cascade leads to haemophilia. Haemophilia affecting weight-bearing joints gives a 'pseudotumour' or haemarthrosis-like condition. Surgery and cryoprecipitate infusions have been the treatment for this condition. Radiocolloids and radiation therapy have been used with some benefit. One case of ankle pseudotumour which was treated by low-dose external beam radiation is presented here. Copyright (1998) Blackwell Science Pty Ltd

  3. Adjuvant radiation therapy in locally advanced non-small cell lung cancer: Executive summary of an American Society for Radiation Oncology (ASTRO) evidence-based clinical practice guideline.

    Science.gov (United States)

    Rodrigues, George; Choy, Hak; Bradley, Jeffrey; Rosenzweig, Kenneth E; Bogart, Jeffrey; Curran, Walter J; Gore, Elizabeth; Langer, Corey; Louie, Alexander V; Lutz, Stephen; Machtay, Mitchell; Puri, Varun; Werner-Wasik, Maria; Videtic, Gregory M M

    2015-01-01

    To provide guidance to physicians and patients with regard to the use of adjuvant external beam radiation therapy (RT) in locally advanced non-small cell lung cancer (LA NSCLC) based on available medical evidence complemented by consensus-based expert opinion. A panel authorized by the American Society for Radiation Oncology (ASTRO) Board of Directors and Guidelines Subcommittee conducted 2 systematic reviews on the following topics: (1) indications for postoperative adjuvant RT and (2) indications for preoperative neoadjuvant RT. Practice guideline recommendations were approved using an a priori-defined consensus-building methodology supported by ASTRO and approved tools for the grading of evidence quality and the strength of guideline recommendations. For patients who have undergone surgical resection, high-level evidence suggests that use of postoperative RT does not influence survival, but optimizes local control for patients with N2 involvement, and its use in the setting of positive margins or gross primary/nodal residual disease is recommended. No high-level evidence exists for the routine use of preoperative induction chemoradiation therapy; however, modern surgical series and a post-hoc Intergroup 0139 clinical trial analysis suggest that a survival benefit may exist if patients are properly selected and surgical techniques/postoperative care is optimized. A consensus and evidence-based clinical practice guideline for the adjuvant radiotherapeutic management of LA NSCLC has been created addressing 2 important questions. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Dosimetric Comparison of Real-Time MRI-Guided Tri-Cobalt-60 Versus Linear Accelerator-Based Stereotactic Body Radiation Therapy Lung Cancer Plans.

    Science.gov (United States)

    Wojcieszynski, Andrzej P; Hill, Patrick M; Rosenberg, Stephen A; Hullett, Craig R; Labby, Zacariah E; Paliwal, Bhudatt; Geurts, Mark W; Bayliss, R Adam; Bayouth, John E; Harari, Paul M; Bassetti, Michael F; Baschnagel, Andrew M

    2017-06-01

    Magnetic resonance imaging-guided radiation therapy has entered clinical practice at several major treatment centers. Treatment of early-stage non-small cell lung cancer with stereotactic body radiation therapy is one potential application of this modality, as some form of respiratory motion management is important to address. We hypothesize that magnetic resonance imaging-guided tri-cobalt-60 radiation therapy can be used to generate clinically acceptable stereotactic body radiation therapy treatment plans. Here, we report on a dosimetric comparison between magnetic resonance imaging-guided radiation therapy plans and internal target volume-based plans utilizing volumetric-modulated arc therapy. Ten patients with early-stage non-small cell lung cancer who underwent radiation therapy planning and treatment were studied. Following 4-dimensional computed tomography, patient images were used to generate clinically deliverable plans. For volumetric-modulated arc therapy plans, the planning tumor volume was defined as an internal target volume + 0.5 cm. For magnetic resonance imaging-guided plans, a single mid-inspiratory cycle was used to define a gross tumor volume, then expanded 0.3 cm to the planning tumor volume. Treatment plan parameters were compared. Planning tumor volumes trended larger for volumetric-modulated arc therapy-based plans, with a mean planning tumor volume of 47.4 mL versus 24.8 mL for magnetic resonance imaging-guided plans ( P = .08). Clinically acceptable plans were achievable via both methods, with bilateral lung V20, 3.9% versus 4.8% ( P = .62). The volume of chest wall receiving greater than 30 Gy was also similar, 22.1 versus 19.8 mL ( P = .78), as were all other parameters commonly used for lung stereotactic body radiation therapy. The ratio of the 50% isodose volume to planning tumor volume was lower in volumetric-modulated arc therapy plans, 4.19 versus 10.0 ( P guided tri-cobalt-60 radiation therapy is capable of delivering lung high

  5. Hospital Quality Factors Influencing the Mobility of Patients for Radical Prostate Cancer Radiation Therapy: A National Population-Based Study.

    Science.gov (United States)

    Aggarwal, Ajay; Lewis, Daniel; Sujenthiran, Arunan; Charman, Susan C; Sullivan, Richard; Payne, Heather; Mason, Malcolm; van der Meulen, Jan

    2017-12-01

    To investigate whether patients requiring radiation treatment are prepared to travel to alternative more distant centers in response to hospital choice policies, and the factors that influence this mobility. We present the results of a national cohort study using administrative hospital data for all 44,363 men who were diagnosed with prostate cancer and underwent radical radiation therapy in the English National Health Service between 2010 and 2014. Using geographic information systems, we investigated the extent to which men choose to travel beyond ("bypass") their nearest radiation therapy center, and we used conditional logistic regression to estimate the effect of hospital and patient characteristics on this mobility. In all, 20.7% of men (n=9161) bypassed their nearest radiation therapy center. Travel time had a very strong impact on where patients moved to for their treatment, but its effect was smaller for men who were younger, more affluent, and from rural areas (P for interaction always quality of radiation therapy delivered are needed to guide patients' choices for radiation therapy treatment. In their absence, patient mobility may negatively affect the efficiency and capacity of a regional or national radiation therapy service and offer perverse incentives for technology adoption. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  6. Evaluation of Delivery Costs for External Beam Radiation Therapy and Brachytherapy for Locally Advanced Cervical Cancer Using Time-Driven Activity-Based Costing.

    Science.gov (United States)

    Bauer-Nilsen, Kristine; Hill, Colin; Trifiletti, Daniel M; Libby, Bruce; Lash, Donna H; Lain, Melody; Christodoulou, Deborah; Hodge, Constance; Showalter, Timothy N

    2018-01-01

    To evaluate the delivery costs, using time-driven activity-based costing, and reimbursement for definitive radiation therapy for locally advanced cervical cancer. Process maps were created to represent each step of the radiation treatment process and included personnel, equipment, and consumable supplies used to deliver care. Personnel were interviewed to estimate time involved to deliver care. Salary data, equipment purchasing information, and facilities costs were also obtained. We defined the capacity cost rate (CCR) for each resource and then calculated the total cost of patient care according to CCR and time for each resource. Costs were compared with 2016 Medicare reimbursement and relative value units (RVUs). The total cost of radiation therapy for cervical cancer was $12,861.68, with personnel costs constituting 49.8%. Brachytherapy cost $8610.68 (66.9% of total) and consumed 423 minutes of attending radiation oncologist time (80.0% of total). External beam radiation therapy cost $4055.01 (31.5% of total). Personnel costs were higher for brachytherapy than for the sum of simulation and external beam radiation therapy delivery ($4798.73 vs $1404.72). A full radiation therapy course provides radiation oncologists 149.77 RVUs with intensity modulated radiation therapy or 135.90 RVUs with 3-dimensional conformal radiation therapy, with total reimbursement of $23,321.71 and $16,071.90, respectively. Attending time per RVU is approximately 4-fold higher for brachytherapy (5.68 minutes) than 3-dimensional conformal radiation therapy (1.63 minutes) or intensity modulated radiation therapy (1.32 minutes). Time-driven activity-based costing was used to calculate the total cost of definitive radiation therapy for cervical cancer, revealing that brachytherapy delivery and personnel resources constituted the majority of costs. However, current reimbursement policy does not reflect the increased attending physician effort and delivery costs of brachytherapy. We

  7. Automated contouring error detection based on supervised geometric attribute distribution models for radiation therapy: A general strategy

    International Nuclear Information System (INIS)

    Chen, Hsin-Chen; Tan, Jun; Dolly, Steven; Kavanaugh, James; Harold Li, H.; Altman, Michael; Gay, Hiram; Thorstad, Wade L.; Mutic, Sasa; Li, Hua; Anastasio, Mark A.; Low, Daniel A.

    2015-01-01

    Purpose: One of the most critical steps in radiation therapy treatment is accurate tumor and critical organ-at-risk (OAR) contouring. Both manual and automated contouring processes are prone to errors and to a large degree of inter- and intraobserver variability. These are often due to the limitations of imaging techniques in visualizing human anatomy as well as to inherent anatomical variability among individuals. Physicians/physicists have to reverify all the radiation therapy contours of every patient before using them for treatment planning, which is tedious, laborious, and still not an error-free process. In this study, the authors developed a general strategy based on novel geometric attribute distribution (GAD) models to automatically detect radiation therapy OAR contouring errors and facilitate the current clinical workflow. Methods: Considering the radiation therapy structures’ geometric attributes (centroid, volume, and shape), the spatial relationship of neighboring structures, as well as anatomical similarity of individual contours among patients, the authors established GAD models to characterize the interstructural centroid and volume variations, and the intrastructural shape variations of each individual structure. The GAD models are scalable and deformable, and constrained by their respective principal attribute variations calculated from training sets with verified OAR contours. A new iterative weighted GAD model-fitting algorithm was developed for contouring error detection. Receiver operating characteristic (ROC) analysis was employed in a unique way to optimize the model parameters to satisfy clinical requirements. A total of forty-four head-and-neck patient cases, each of which includes nine critical OAR contours, were utilized to demonstrate the proposed strategy. Twenty-nine out of these forty-four patient cases were utilized to train the inter- and intrastructural GAD models. These training data and the remaining fifteen testing data sets

  8. Monte Carlo techniques in radiation therapy

    CERN Document Server

    Verhaegen, Frank

    2013-01-01

    Modern cancer treatment relies on Monte Carlo simulations to help radiotherapists and clinical physicists better understand and compute radiation dose from imaging devices as well as exploit four-dimensional imaging data. With Monte Carlo-based treatment planning tools now available from commercial vendors, a complete transition to Monte Carlo-based dose calculation methods in radiotherapy could likely take place in the next decade. Monte Carlo Techniques in Radiation Therapy explores the use of Monte Carlo methods for modeling various features of internal and external radiation sources, including light ion beams. The book-the first of its kind-addresses applications of the Monte Carlo particle transport simulation technique in radiation therapy, mainly focusing on external beam radiotherapy and brachytherapy. It presents the mathematical and technical aspects of the methods in particle transport simulations. The book also discusses the modeling of medical linacs and other irradiation devices; issues specific...

  9. An Excel-Based System to Manage Radiation Safety for the Family of Patients Undergoing131I Therapy.

    Science.gov (United States)

    Steward, Palmer G

    2017-06-01

    The purpose of this study was to develop spreadsheet workbooks that assist in the radiation safety counseling of 131 I therapy patients and their families, providing individualized guidelines that avoid imposing overly conservative restrictions on family members and others. Methods: The mathematic model included biphasic patient radionuclide retention. The extrathyroidal component was a cylindric volume with a diameter corresponding to the patient's size and included patient self-absorption, whereas the thyroidal component was a point source whose transmission was reduced by self-absorption. A separate model in which the thyroid, extrathyroid, and bladder compartments fed serially from one to the next was developed to depict the radionuclide levels within the patient and to estimate the activity entering the environment at each urination. Results: The system was organized into a set of 4 workbooks: the first to be used with ablation patients prepared using thyrogen, the second with ablation patients prepared by deprivation, the third with hyperthyroid patients, and the fourth with the unusual hyperthyroid patient who finds the restrictions to be oppressive and returns 5-10 d after administration for a measurement and reassessment. The workbooks evaluated the radiation field strength external to the patient and indicated restrictions based on selected dose limits. To assist physicians in suggesting contamination precautions, the workbooks also evaluated the radioactivity present within the patient and the estimated discharge into the environment as a function of time. Conclusion: The workbooks that were developed assist the radiation safety counselor in individualizing radiation protection procedures for the family of patients undergoing 131 I therapy. The workbook system avoids overly conservative assumptions while permitting selection of appropriate dose limits for each individual. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  10. Radiation therapy and herpes zoster

    International Nuclear Information System (INIS)

    Kaneko, Itsuo; Matsushima, Hideno; Yamada, Teruyo; Moriya, Hiroshi

    1975-01-01

    The relationship between herpes zoster and radiation therapy was discussed and the combination of herpes zoster with malignancies was observed. Reported were five cases of herpes zoster (four breast and one lung carcinoma) out of 317 cases of malignancies which were irradiated in our clinic and include considerations about the etiologic relationship. (J.P.N.)

  11. Impact of radiation therapy on sexual life

    International Nuclear Information System (INIS)

    Leroy, T.; Gabelle Flandin, I.; Habold, D.; Hannoun-Levi, J.M.

    2012-01-01

    The aim of this study was to evaluate the impact of radiation therapy on sexual life. The analysis was based on a Pubmed literature review. The keywords used for this research were 'sexual, radiation, oncology, and cancer'. After a brief reminder on the anatomy and physiology, we explained the main complications of radiation oncology and their impact on sexual life. Preventive measures and therapeutic possibilities were discussed. Radiation therapy entails local, systematic and psychological after-effects. For women, vaginal stenosis and dyspareunia represent the most frequent side effects. For men, radiation therapy leads to erectile disorders for 25 to 75% of the patients. These complications have an echo often mattering on the patient quality of life of and on their sexual life post-treatment reconstruction. The knowledge of the indications and the various techniques of irradiation allow reducing its potential sexual morbidity. The information and the education of patients are essential, although often neglected. In conclusion, radiation therapy impacts in variable degrees on the sexual life of the patients. Currently, there are not enough preventive and therapeutic means. Patient information and the early screening of the sexual complications are at stake in the support of patients in the reconstruction of their sexual life. (authors)

  12. Radiation dosimetry for radionuclide therapy

    International Nuclear Information System (INIS)

    Kim, Eun Hee

    2001-01-01

    The radionuclide therapy is a protocol for tumor control by administering radionuclides as the cytotoxic agents. Radionuclides concentrated at the site of cancerous lesion are expected to kill the cancerous cells with minimal injury to the normal tissue. The efficacy of every radionuclide treatment can be evaluated by examining the toxicity to the lesion differentiated from that to the normal tissue. Radiation dosimerty is the procedure of quantitating the energy absorbed by target volumes of interest. Dosimetric information plays an indicator of the expected radiation damage and thus the therapeutic efficacy. This paper summarizes the dosimetric aspects in radionuclide therapy in terms of radionuclides of use, radionuclides of use, radiation dosimetry methodology and considerations for each treatment in practical use

  13. Magnetic Resonance Imaging–Guided versus Surrogate-Based Motion Tracking in Liver Radiation Therapy: A Prospective Comparative Study

    Energy Technology Data Exchange (ETDEWEB)

    Paganelli, Chiara, E-mail: chiara.paganelli@polimi.it [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Seregni, Matteo; Fattori, Giovanni [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Summers, Paul [Division of Radiology, Istituto Europeo di Oncologia, Milano (Italy); Bellomi, Massimo [Division of Radiology, Istituto Europeo di Oncologia, Milano (Italy); Department of Health Sciences, Università degli Studi di Milano, Milano (Italy); Baroni, Guido; Riboldi, Marco [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit, CNAO Foundation, Pavia (Italy)

    2015-03-15

    Purpose: This study applied automatic feature detection on cine–magnetic resonance imaging (MRI) liver images in order to provide a prospective comparison between MRI-guided and surrogate-based tracking methods for motion-compensated liver radiation therapy. Methods and Materials: In a population of 30 subjects (5 volunteers plus 25 patients), 2 oblique sagittal slices were acquired across the liver at high temporal resolution. An algorithm based on scale invariant feature transform (SIFT) was used to extract and track multiple features throughout the image sequence. The position of abdominal markers was also measured directly from the image series, and the internal motion of each feature was quantified through multiparametric analysis. Surrogate-based tumor tracking with a state-of-the-art external/internal correlation model was simulated. The geometrical tracking error was measured, and its correlation with external motion parameters was also investigated. Finally, the potential gain in tracking accuracy relying on MRI guidance was quantified as a function of the maximum allowed tracking error. Results: An average of 45 features was extracted for each subject across the whole liver. The multi-parametric motion analysis reported relevant inter- and intrasubject variability, highlighting the value of patient-specific and spatially-distributed measurements. Surrogate-based tracking errors (relative to the motion amplitude) were were in the range 7% to 23% (1.02-3.57mm) and were significantly influenced by external motion parameters. The gain of MRI guidance compared to surrogate-based motion tracking was larger than 30% in 50% of the subjects when considering a 1.5-mm tracking error tolerance. Conclusions: Automatic feature detection applied to cine-MRI allows detailed liver motion description to be obtained. Such information was used to quantify the performance of surrogate-based tracking methods and to provide a prospective comparison with respect to MRI

  14. Micro-scale characterization of a CMOS-based neutron detector for in-phantom measurements in radiation therapy

    Science.gov (United States)

    Arbor, Nicolas; Higueret, Stephane; Husson, Daniel

    2018-04-01

    The CMOS sensor AlphaRad has been designed at the IPHC Strasbourg for real-time monitoring of fast and thermal neutrons over a full energy spectrum. Completely integrated, highly transparent to photons and optimized for low power consumption, this sensor offers very interesting characteristics for the study of internal neutrons in radiation therapy with anthropomorphic phantoms. However, specific effects related to the CMOS metal substructure and to the charge collection process of low energy particles must be carefully estimated before being used for medical applications. We present a detailed characterization of the AlphaRad chip in the MeV energy range using proton and alpha micro-beam experiments performed at the AIFIRA facility (CENBG, Bordeaux). Two-dimensional maps of the charge collection were carried out on a micro-metric scale to be integrated into a Geant4 Monte Carlo simulation of the system. The gamma rejection, as well as the fast and thermal neutrons separation, were studied using both simulation and experimental data. The results highlight the potential of a future system based on CMOS sensor for in-phantom neutron detection in radiation therapies.

  15. Convex reformulation of biologically-based multi-criteria intensity-modulated radiation therapy optimization including fractionation effects.

    Science.gov (United States)

    Hoffmann, Aswin L; den Hertog, Dick; Siem, Alex Y D; Kaanders, Johannes H A M; Huizenga, Henk

    2008-11-21

    Finding fluence maps for intensity-modulated radiation therapy (IMRT) can be formulated as a multi-criteria optimization problem for which Pareto optimal treatment plans exist. To account for the dose-per-fraction effect of fractionated IMRT, it is desirable to exploit radiobiological treatment plan evaluation criteria based on the linear-quadratic (LQ) cell survival model as a means to balance the radiation benefits and risks in terms of biologic response. Unfortunately, the LQ-model-based radiobiological criteria are nonconvex functions, which make the optimization problem hard to solve. We apply the framework proposed by Romeijn et al (2004 Phys. Med. Biol. 49 1991-2013) to find transformations of LQ-model-based radiobiological functions and establish conditions under which transformed functions result in equivalent convex criteria that do not change the set of Pareto optimal treatment plans. The functions analysed are: the LQ-Poisson-based model for tumour control probability (TCP) with and without inter-patient heterogeneity in radiation sensitivity, the LQ-Poisson-based relative seriality s-model for normal tissue complication probability (NTCP), the equivalent uniform dose (EUD) under the LQ-Poisson model and the fractionation-corrected Probit-based model for NTCP according to Lyman, Kutcher and Burman. These functions differ from those analysed before in that they cannot be decomposed into elementary EUD or generalized-EUD functions. In addition, we show that applying increasing and concave transformations to the convexified functions is beneficial for the piecewise approximation of the Pareto efficient frontier.

  16. Uncertainties in CT-Based Radiation Therapy Treatment Planning Associated with Patient Breathing

    International Nuclear Information System (INIS)

    Balter, James M.; Ten Haken, Randall K.; Lawrence, Theodore S.; Lam, Kwok L.; Robertson, John M.

    1996-01-01

    Purpose: To evaluate uncertainties associated with treatment-planning computed tomography (CT) data obtained with the patient breathing freely. Methods and Materials: Patients with thoracic or abdominal tumors underwent a standard treatment-planning CT study while breathing quietly and freely, followed by CT scans while holding their breath at normal inhalation and normal exhalation. Identical treatment plans on all three CT data sets for each patient pointed out differences in: (a) radiation path lengths; (b) positions of the organs; (c) physical volumes of the lung, liver, and kidneys; (d) the interpretation of plan evaluation tools such as dose-volume histograms and normal tissue complication probability (NTCP) models; and (e) how well the planning CT data set represented the average of the inhalation and exhalation studies. Results: Inhalation and exhalation data differ in terms of radiation path length (nearly one quarter of the cases had path-length differences > 1 cm), although the free breathing and average path lengths do not exhibit large differences (0-9 mm). Liver and kidney movements averaged 2 cm, whereas differences between the free breathing and average positions averaged 0.6 cm. The physical volume of the liver between the free breathing and static studies varied by as much as 12%. The NTCP calculations on exhale and inhale studies varied from 3 to 43% for doses that resulted in a 15% NTCP on the free-breathing studies. Conclusion: Free-breathing CT studies may improperly estimate the position and volume of critical structures, and thus may mislead evaluation of plans based on such volume dependent criteria such as dose-volume histograms and NTCP calculations

  17. Radiation therapy - questions to ask your doctor

    Science.gov (United States)

    What to ask your doctor about radiation therapy ... National Cancer Institute website. Radiation therapy and you: support for people with cancer. www.cancer.gov/publications/patient-education/radiationttherapy.pdf . Updated May 2007. Accessed December ...

  18. Analytical investigation of the possibility of parameter invariant TCP-based radiation therapy plan ranking.

    Science.gov (United States)

    Stavreva, Nadejda; Nahum, Alan; Markov, Krassimir; Ruggieri, Ruggero; Stavrev, Pavel

    2010-11-01

    To analytically investigate the possibility of a parameter invariant ranking of radiotherapy (RT) plans based on comparing the tumor control probabilities (TCPs) produced by the competing plans for different values of the radiobiological model parameters determining the radiation response. Individual TCP models based on the Single hit model of cell kill and on the linear-quadratic (LQ) model of cell damage, with and without repopulation, are considered. The tumor dose distributions in case of heterogeneous dose irradiation are described by a Gaussian distribution function on the basis of which a TCP expression is derived depending only on the mean dose to the tumor and its standard deviation and the TCP model parameters. It is shown that in case of homogeneous dose to the tumor the plan ranking in terms of TCP is parameter invariant. In case of heterogeneous dose to the tumor there are cases when the plan ranking is parameter invariant and cases when the parameter invariance is violated. An interesting dependence of the extent of the parameter invariance violation on the model of cell kill as well as on the size and repopulation rate of the tumor is noted. We conclude that in many cases RT plan ranking in terms of TCP is parameter invariant. However, since there exist cases where the parameter invariance is lost an investigation of the specific plans to be ranked should be performed applying the proposed approach.

  19. Why do patients drop out during radiation therapy?

    International Nuclear Information System (INIS)

    Huh, Seung Jae; Ahn, Yong Chan; Kim, Dae Yong; Shin, Kyung Hwan; Lee, Kyu Chan; Chong, Won A; Kim, Hyun Joo; Wu, Hong Gyun

    1998-01-01

    This study is to see how much proportion of the patients receiving radiation therapy drop out during radiation therapy and to analyze the reason for the incomplete treatment. The base population of this study was 1,100 patients with registration numbers 901 through 2,000 at Department of Radiation Oncology, Samsung Medical Center, Seoul, Korea. Authors investigated the incidence of incomplete radiation therapy, which was defined as less than 95% of initially planned radiation dose, and the reasons for incomplete radiation therapy. One hundred and twenty eight patients (12%) did not complete the planned radiation therapy. The performance status of the incompletely treated patients was generally poorer than that of the base population, and the aim of radiation therapy was more commonly palliative. The most common reason for not completing the planned treatment was the patients' refusal of further radiation therapy because of the distrust of radiation therapy and/or the poor economic status. Careful case selection for radiation therapy with consideration of the socioeconomic status of the patients in addition to the clinical indication would be necessary for the reduction of incomplete treatment, especially in the palliative setting

  20. A new Monte Carlo-based treatment plan optimization approach for intensity modulated radiation therapy.

    Science.gov (United States)

    Li, Yongbao; Tian, Zhen; Shi, Feng; Song, Ting; Wu, Zhaoxia; Liu, Yaqiang; Jiang, Steve; Jia, Xun

    2015-04-07

    Intensity-modulated radiation treatment (IMRT) plan optimization needs beamlet dose distributions. Pencil-beam or superposition/convolution type algorithms are typically used because of their high computational speed. However, inaccurate beamlet dose distributions may mislead the optimization process and hinder the resulting plan quality. To solve this problem, the Monte Carlo (MC) simulation method has been used to compute all beamlet doses prior to the optimization step. The conventional approach samples the same number of particles from each beamlet. Yet this is not the optimal use of MC in this problem. In fact, there are beamlets that have very small intensities after solving the plan optimization problem. For those beamlets, it may be possible to use fewer particles in dose calculations to increase efficiency. Based on this idea, we have developed a new MC-based IMRT plan optimization framework that iteratively performs MC dose calculation and plan optimization. At each dose calculation step, the particle numbers for beamlets were adjusted based on the beamlet intensities obtained through solving the plan optimization problem in the last iteration step. We modified a GPU-based MC dose engine to allow simultaneous computations of a large number of beamlet doses. To test the accuracy of our modified dose engine, we compared the dose from a broad beam and the summed beamlet doses in this beam in an inhomogeneous phantom. Agreement within 1% for the maximum difference and 0.55% for the average difference was observed. We then validated the proposed MC-based optimization schemes in one lung IMRT case. It was found that the conventional scheme required 10(6) particles from each beamlet to achieve an optimization result that was 3% difference in fluence map and 1% difference in dose from the ground truth. In contrast, the proposed scheme achieved the same level of accuracy with on average 1.2 × 10(5) particles per beamlet. Correspondingly, the computation

  1. Using gEUD based plan analysis method to evaluate proton vs. photon plans for lung cancer radiation therapy.

    Science.gov (United States)

    Xiao, Zhiyan; Zou, Wei J; Chen, Ting; Yue, Ning J; Jabbour, Salma K; Parikh, Rahul; Zhang, Miao

    2018-03-01

    The goal of this study was to exam the efficacy of current DVH based clinical guidelines draw from photon experience for lung cancer radiation therapy on proton therapy. Comparison proton plans and IMRT plans were generated for 10 lung patients treated in our proton facility. A gEUD based plan evaluation method was developed for plan evaluation. This evaluation method used normal lung gEUD(a) curve in which the model parameter "a" was sampled from the literature reported value. For all patients, the proton plans delivered lower normal lung V 5 Gy with similar V 20 Gy and similar target coverage. Based on current clinical guidelines, proton plans were ranked superior to IMRT plans for all 10 patients. However, the proton and IMRT normal lung gEUD(a) curves crossed for 8 patients within the tested range of "a", which means there was a possibility that proton plan would be worse than IMRT plan for lung sparing. A concept of deficiency index (DI) was introduced to quantify the probability of proton plans doing worse than IMRT plans. By applying threshold on DI, four patients' proton plan was ranked inferior to the IMRT plan. Meanwhile if a threshold to the location of curve crossing was applied, 6 patients' proton plan was ranked inferior to the IMRT plan. The contradictory ranking results between the current clinical guidelines and the gEUD(a) curve analysis demonstrated there is potential pitfalls by applying photon experience directly to the proton world. A comprehensive plan evaluation based on radio-biological models should be carried out to decide if a lung patient would really be benefit from proton therapy. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  2. Computer models for optimizing radiation therapy

    International Nuclear Information System (INIS)

    Duechting, W.

    1998-01-01

    The aim of this contribution is to outline how methods of system analysis, control therapy and modelling can be applied to simulate normal and malignant cell growth and to optimize cancer treatment as for instance radiation therapy. Based on biological observations and cell kinetic data, several types of models have been developed describing the growth of tumor spheroids and the cell renewal of normal tissue. The irradiation model is represented by the so-called linear-quadratic model describing the survival fraction as a function of the dose. Based thereon, numerous simulation runs for different treatment schemes can be performed. Thus, it is possible to study the radiation effect on tumor and normal tissue separately. Finally, this method enables a computer-assisted recommendation for an optimal patient-specific treatment schedule prior to clinical therapy. (orig.) [de

  3. Radiation therapy for carcinoma of the endometrium

    International Nuclear Information System (INIS)

    Potish, R.A.

    1987-01-01

    Carcinoma of the endometrium is the most common malignant tumor in the female genital tract. Radiation therapy continues to play a major role in the management of endometrial carcinoma, both as primary therapy and as adjuvant treatment. The utility of pelvic external beam therapy and intracavitary therapy is long established. However, the modern era of surgical staging has lead to an appreciation of the role of radiation therapy beyond the pelvis. Radiation therapy has been shown to be of particular benefit in peritoneal and nodal spread. The classic management of endometrial cancer is reviewed and relatively new and somewhat controversial topics, such as preoperative intracavitary therapy followed by external beam therapy are discussed

  4. Proton Radiation Therapy in the Hospital Environment: Conception, Development, and Operation of the Initial Hospital-Based Facility

    Science.gov (United States)

    Slater, James M.; Slater, Jerry D.; Wroe, Andrew J.

    The world's first hospital-based proton treatment center opened at Loma Linda University Medical Center in 1990, following two decades of development. Patients' needs were the driving force behind its conception, development, and execution; the primary needs were delivery of effective conformal doses of ionizing radiation and avoidance of normal tissue to the maximum extent possible. The facility includes a proton synchrotron and delivery system developed in collaboration with physicists and engineers at Fermi National Accelerator Laboratory and from other high-energy-physics laboratories worldwide. The system, operated and maintained by Loma Linda personnel, was designed to be safe, reliable, flexible in utilization, efficient in use, and upgradeable to meet demands of changing patient needs and advances in technology. Since the facility opened, nearly 14,000 adults and children have been treated for a wide range of cancers and other diseases. Ongoing research is expanding the applications of proton therapy, while reducing costs.

  5. Radiation therapy of gynecological cancer

    International Nuclear Information System (INIS)

    Nori, D.; Hilaris, B.S.

    1987-01-01

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

  6. Treatment charts in radiation therapy

    International Nuclear Information System (INIS)

    Macia, M.; De Blas, R.; Monfa, C.; Bonet, A.; Rubio, A.M.

    1993-01-01

    The radiotherapy treatment chart (dose prescription, set-up parameters, dose computation and daily dose recording form) represents an important working tool in radiotherapy, not only as a compilation of data, but also as a method of communication among physicians, physicists and technicians. In addition to administrative and medical data, physical and simulation data that are indispensable for the daily accurate reproduction of the therapy procedures should be recorded, as well as accurate daily entries of the fractional and cumulative absorbed doses. Moreover, any radiation therapy quality assurance programme must rely on the accessibility of the radiation treatment history and a correct record of the therapy protocol in order to be verifiable. We have analysed the treatment charts of 92 European Departments of Radiation Oncology, with the aim of identifying their salient characteristics and data recorded. The study shows strong differences among the charts analysed, not only in the amount of information recorded, but also in the kind of data and concepts used. (author) 6 refs., 1 fig

  7. Multibeam radiation therapy treatment application

    International Nuclear Information System (INIS)

    Manens, J.P.; Le Gall, G.; Chenal, C.; Ben Hassel, M.; Fresne, F.; Barillot, C.; Gibaud, B.; Lemoine, D.; Bouliou, A.; Scarabin, J.M.

    1991-01-01

    A software package has been developed for multibeam radiation therapy treatment application. We present in this study a computer-assisted dosimetric planning procedure which includes: i), an analytical stage for setting up the large volume via 2D and 3D displays; ii), a planning stage for issue of a treatment strategy including dosimetric simulations; and iii), a treatment stage to drive the target volume to the radiation unit isocenter. The combined use of stereotactic methods and multimodality imagery ensures spatial coherence and makes target definition and cognition of structure environment more accurate. The dosimetric planning suited to the spatial reference (the stereotactic frame) guarantees optimal distribution of the dose, computed by the original 3D volumetric algorithm. A computer-driven chair-framework cluster was designed to position the target volume at the radiation unit isocenter [fr

  8. Late complications of radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Masaki, Norie [Osaka Prefectural Center for Adult Diseases (Japan)

    1998-03-01

    There are cases in which, although all traces of acute radiation complications seem to have disappeared, late complications may appear months or years to become apparent. Trauma, infection or chemotherapy may sometimes recall radiation damage and irreversible change. There were two cases of breast cancer that received an estimated skin dose in the 6000 cGy range followed by extirpation of the residual tumor. The one (12 y.o.) developed atrophy of the breast and severe teleangiectasis 18 years later radiotherapy. The other one (42 y.o.) developed severe skin necrosis twenty years later radiotherapy after administration of chemotherapy and received skin graft. A case (52 y.o.) of adenoidcystic carcinoma of the trachea received radiation therapy. The field included the thoracic spinal cord which received 6800 cGy. Two years and 8 months after radiation therapy she developed complete paraplegia and died 5 years later. A truly successful therapeutic outcome requires that the patient be alive, cured and free of significant treatment-related morbidity. As such, it is important to assess quality of life in long-term survivors of cancer treatment. (author)

  9. Late complications of radiation therapy

    International Nuclear Information System (INIS)

    Masaki, Norie

    1998-01-01

    There are cases in which, although all traces of acute radiation complications seem to have disappeared, late complications may appear months or years to become apparent. Trauma, infection or chemotherapy may sometimes recall radiation damage and irreversible change. There were two cases of breast cancer that received an estimated skin dose in the 6000 cGy range followed by extirpation of the residual tumor. The one (12 y.o.) developed atrophy of the breast and severe teleangiectasis 18 years later radiotherapy. The other one (42 y.o.) developed severe skin necrosis twenty years later radiotherapy after administration of chemotherapy and received skin graft. A case (52 y.o.) of adenoidcystic carcinoma of the trachea received radiation therapy. The field included the thoracic spinal cord which received 6800 cGy. Two years and 8 months after radiation therapy she developed complete paraplegia and died 5 years later. A truly successful therapeutic outcome requires that the patient be alive, cured and free of significant treatment-related morbidity. As such, it is important to assess quality of life in long-term survivors of cancer treatment. (author)

  10. 4-1BB Aptamer-Based Immunomodulation Enhances the Therapeutic Index of Radiation Therapy in Murine Tumor Models

    Energy Technology Data Exchange (ETDEWEB)

    Benaduce, Ana Paula; Brenneman, Randall; Schrand, Brett; Pollack, Alan; Gilboa, Eli; Ishkanian, Adrian, E-mail: aishkanian@med.miami.edu

    2016-10-01

    Purpose: To report a novel strategy using oligonucleotide aptamers to 4-1BB as an alternate method for costimulation, and show that combinatorial therapy with radiation improves the therapeutic ratio over equivalent monoclonal antibodies. Methods and Materials: Subcutaneous 4T1 (mouse mammary carcinoma) tumors were established (approximately 100 mm{sup 3}), and a radiation therapy (RT) dose/fractionation schedule that optimally synergizes with 4-1BB monoclonal antibody (mAb) was identified. Comparable tumor control and animal survival was observed when either 4-1BB antibody or aptamer were combined with RT using models of breast cancer and melanoma (4T1 and B16-F10). Off-target CD8{sup +} T-cell toxicity was evaluated by quantification of CD8{sup +} T cells in livers and spleens of treated animals. Results: When combined with 4-1BB mAb, significant differences in tumor control were observed by varying RT dose and fractionation schedules. Optimal synergy between RT and 4-1BB mAb was observed at 5 Gy × 6. Testing 4-1BB mAb and aptamer independently using the optimal RT (5 Gy × 6 for 4T1/Balb/c and 12 Gy × 1 for B16/C57BL6J mouse models) revealed equivalent tumor control using 4-1BB aptamer and 4-1BB mAb. 4-1BB mAb, but not 4-1BB aptamer-treated animals, exhibited increased lymphocytic liver infiltrates and increased splenic and liver CD8{sup +} T cells. Conclusions: Radiation therapy synergizes with 4-1BB mAb, and this effect is dependent on RT dose and fractionation. Tumor control by 4-1BB aptamer is equivalent to 4-1BB mAb when combined with optimal RT dose, without eliciting off-target liver and spleen CD8{sup +} expansion. 4-1BB aptamer-based costimulation affords a comparable and less toxic strategy to augment RT-mediated tumor control.

  11. Development of local radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hoon; Lim, Sang Moo; Choi, Chang Woon; Chai, Jong Su; Kim, Eun Hee; Kim, Mi Sook; Yoo, Seong Yul; Cho, Chul Koo; Lee, Yong Sik; Lee, Hyun Moo

    1999-04-01

    The major limitations of radiation therapy for cancer are the low effectiveness of low LET and inevitable normal tissue damage. Boron Neutron Capture Therapy (BNCT) is a form of potent radiation therapy using Boron-10 having a high propensityof capturing theraml neutrons from nuclear reactor and reacting with a prompt nuclear reaction. Photodynamic therapy is a similiar treatment of modality to BNCT using tumor-seeking photosenistizer and LASER beam. If Boron-10 and photosensitizers are introduced selectively into tumor cells, it is theoretically possible to destroy the tumor and to spare the surrounding normal tissue. Therefore, BNCT and PDT will be new potent treatment modalities in the next century. In this project, we performed PDT in the patients with bladder cancers, oropharyngeal cancer, and skin cancers. Also we developed I-BPA, new porphyrin compounds, methods for estimation of radiobiological effect of neutron beam, and superficial animal brain tumor model. Furthermore, we prepared preclinical procedures for clinical application of BNCT, such as the macro- and microscopic dosimetry, obtaining thermal neutron flux from device used for fast neutron production in KCCH have been performed.

  12. Development of local radiation therapy

    International Nuclear Information System (INIS)

    Lee, Seung Hoon; Lim, Sang Moo; Choi, Chang Woon; Chai, Jong Su; Kim, Eun Hee; Kim, Mi Sook; Yoo, Seong Yul; Cho, Chul Koo; Lee, Yong Sik; Lee, Hyun Moo

    1999-04-01

    The major limitations of radiation therapy for cancer are the low effectiveness of low LET and inevitable normal tissue damage. Boron Neutron Capture Therapy (BNCT) is a form of potent radiation therapy using Boron-10 having a high propensityof capturing theraml neutrons from nuclear reactor and reacting with a prompt nuclear reaction. Photodynamic therapy is a similiar treatment of modality to BNCT using tumor-seeking photosenistizer and LASER beam. If Boron-10 and photosensitizers are introduced selectively into tumor cells, it is theoretically possible to destroy the tumor and to spare the surrounding normal tissue. Therefore, BNCT and PDT will be new potent treatment modalities in the next century. In this project, we performed PDT in the patients with bladder cancers, oropharyngeal cancer, and skin cancers. Also we developed I-BPA, new porphyrin compounds, methods for estimation of radiobiological effect of neutron beam, and superficial animal brain tumor model. Furthermore, we prepared preclinical procedures for clinical application of BNCT, such as the macro- and microscopic dosimetry, obtaining thermal neutron flux from device used for fast neutron production in KCCH have been performed

  13. Criteria and standards for radiation therapy (megavoltage) in southeastern Michigan

    International Nuclear Information System (INIS)

    1979-01-01

    The criteria and standards presented in this document provide the basis for the review of proposals to establish, expand or alter institutionally-based radiation therapy services, the criteria developed should provide sufficient guidance to the Plan Implementation Committee of CHPC-SEM to enable it to accomplish the following: Assure the existence of sufficient treatment capacity to serve the identified radiation therapy needs of the Southeastern Michigan community; Assure the residents of Southeastern Michigan of reasonable access to radiation therapy services; Assure that the radiation therapy services offered are of good quality; Avoid unnecessary and wasteful duplication of radiation therapy equipment and services; and promote the effective operation of the health care system in Southeastern Michigan. These criteria and standards also should provide guidance to providers who may consider initiating a new radiation therapy service or altering an existing service or program

  14. Combined therapy of urinary bladder radiation injury

    International Nuclear Information System (INIS)

    Zaderin, V.P.; Polyanichko, M.F.

    1982-01-01

    A scheme of therapy of radiation cystitis is suggested. It was developed on the basis of evaluation of literature data and clinical of 205 patients with radiation injury of the urinary bladder. The method is based on general and local therapy of damaged tissues by antiinflammatory drugs, anesthetics and stimulators of reparative regeneration. Severe ulcerative and incrustation cystites, refractory to conservative therapy, were treated by surgery, using antiseptics and reparation stimulators before, during and after operation. As a result, there were hardly any complications after reconstruction of the bladder with intestinal and peritoneal tissues. 104 patients (96.1%) were cured completely and ability to work was restored in 70 patients (76.9%) [ru

  15. Radiosensitivity Differences Between Liver Metastases Based on Primary Histology Suggest Implications for Clinical Outcomes After Stereotactic Body Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Kamran A.; Caudell, Jimmy J. [Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida (United States); El-Haddad, Ghassan [Department of Interventional Radiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida (United States); Berglund, Anders E.; Welsh, Eric A. [Department of Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida (United States); Yue, Binglin [Department of Biostastistics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida (United States); Hoffe, Sarah E.; Naghavi, Arash O.; Abuodeh, Yazan A.; Frakes, Jessica M. [Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida (United States); Eschrich, Steven A. [Department of Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida (United States); Torres-Roca, Javier F., E-mail: Javier.torresroca@moffitt.org [Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida (United States)

    2016-08-01

    Purpose/Objectives: Evidence from the management of oligometastases with stereotactic body radiation therapy (SBRT) reveals differences in outcomes based on primary histology. We have previously identified a multigene expression index for tumor radiosensitivity (RSI) with validation in multiple independent cohorts. In this study, we assessed RSI in liver metastases and assessed our clinical outcomes after SBRT based on primary histology. Methods and Materials: Patients were identified from our prospective, observational protocol. The previously tested RSI 10 gene assay was run on samples and calculated using the published algorithm. An independent cohort of 33 patients with 38 liver metastases treated with SBRT was used for clinical correlation. Results: A total of 372 unique metastatic liver lesions were identified for inclusion from our prospective, institutional metadata pool. The most common primary histologies for liver metastases were colorectal adenocarcinoma (n=314, 84.4%), breast adenocarcinoma (n=12, 3.2%), and pancreas neuroendocrine (n=11, 3%). There were significant differences in RSI of liver metastases based on histology. The median RSIs for liver metastases in descending order of radioresistance were gastrointestinal stromal tumor (0.57), melanoma (0.53), colorectal neuroendocrine (0.46), pancreas neuroendocrine (0.44), colorectal adenocarcinoma (0.43), breast adenocarcinoma (0.35), lung adenocarcinoma (0.31), pancreas adenocarcinoma (0.27), anal squamous cell cancer (0.22), and small intestine neuroendocrine (0.21) (P<.0001). The 12-month and 24-month Kaplan-Meier rates of local control (LC) for colorectal lesions from the independent clinical cohort were 79% and 59%, compared with 100% for noncolorectal lesions (P=.019), respectively. Conclusions: In this analysis, we found significant differences based on primary histology. This study suggests that primary histology may be an important factor to consider in SBRT radiation dose selection.

  16. Fractionated stereotactic radiation therapy improves cranial neuropathies in patients with skull base meningiomas: a retrospective cohort study

    International Nuclear Information System (INIS)

    Skull base meningiomas commonly present with cranial neuropathies. Fractionated stereotactic radiation therapy (FSRT) has been used to treat these tumors with excellent local control, but rates of improvement in cranial neuropathies have not been well defined. We review the experience at Thomas Jefferson University using FSRT in the management of these patients with a focus on symptom outcomes. We identified 225 cases of skull base meningiomas treated with FSRT at Thomas Jefferson University from 1994 through 2009. The target volume was the enhancing tumor, treated to a standard prescription dose of 54 Gy. Symptoms at the time of RT were classified based on the cranial nerve affected. Logistic regression was performed to determine predictors of symptom improvement after FSRT. The median follow-up time was 4.4 years. In 92% of cases, patients were symptomatic at the time of RT; the most common were impaired visual field/acuity (58%) or extraocular movements (34%). After FSRT, durable improvement of at least one symptom occurred in 57% of cases, including 40% of visual acuity/visual field deficits, and 40% of diplopia/ptosis deficits. Of all symptomatic patients, 27% experienced improvement of at least one symptom within 2 months of the end of RT. FSRT is very effective in achieving improvement of cranial neuropathies from skull base meningiomas, particularly visual symptoms. Over half of treated patients experience a durable improvement of at least one symptom, frequently within 2 months from the end of RT

  17. Radiation Therapy for Carcinoma of the Oropharynx

    Energy Technology Data Exchange (ETDEWEB)

    Park, In Kyu; Kim, Jae Choel [Kyungpook National University College of Medicine, Taegu (Korea, Republic of)

    1996-06-15

    Purpose : A retrospective analysis for patients with oropharyngeal carcinoma who were treated with radiation was performed to assess the results of treatment and patterns of failure, and to identify the factors that might influence survival. Methods and Materials : From March 1985 through June 1993, 53 patients with oropharyngeal carcinoma were treated with either radiation therapy alone or combination of neoadjuvant chemotherapy and radiation therapy at the Department of Radiation Oncology, Kyungpook National University Hospital. Patients' ages ranged from 31 to 73 years with a median age of 54 years. There were 47 men and 6 women. Forty-two patients (79.2%) had squamous cell carcinoma, 10 patients (18.9%) had undifferentiated carcinoma and 1 patient (1.9%) had adenoid cystic carcinoma. There were 2 patients with stage I 12 patients with stage II, 12 patients with stage III and 27 patients with stage IV. According to the TNM classification, patients were distributed as follows: T1 7, T2 2, T3 10, T4 7, TX 1, and N0 17, N1 13, N2 21, N3 2. The primary tumor sites were tonsillar region in 36 patients (67.9%) base of the tongue in 12 patients (22.6%), and soft palate in 5 patients (9.4%). Twenty-five patients were treated with radiation therapy alone and twenty-eight patients were treated with one to three courses of chemotherapy followed by radiation therapy. Chemotherapeutic regimens used were either CF (cisplatin and 5-fluorouracil) or CVB (cisplatin, vincristine and bleomycin), Radiation therapy was delivered 180-200 cGy daily,five times a week using 6 MV X-ray with or without 8-10 MeV electron beams. A tumor dose ranged from 4500 cGy to 7740 cGy with a median dose of 7100 cGy. The follow-up time ranged from 4months to 99 months with a median of 21 months. Results : Thrity-seven patients (69.8%) achieved a CR (complete response) and PR (partial response) in 16 patients (30.2%) after radiation therapy. The overall survival rates were 47% at 2 years and 42% at

  18. Contemporary radiation therapy in combined modality therapy for Hodgkin lymphoma.

    Science.gov (United States)

    Narang, Amol K; Terezakis, Stephanie A

    2015-05-01

    The advent of effective combination chemotherapy markedly changed the management of Hodgkin lymphoma, establishing combined modality therapy as the standard of care for most patients with this disease. In response, significant interest has been shown in refining the delivery of radiation in the combined modality setting such that toxicity is minimized while still preserving disease control. An understanding of the way in which radiation treatment fields, prescription dose, and advanced technology have evolved to accomplish these goals is critical. Moreover, fluency in the clinical literature exploring contemporary questions, such as the omission of radiation and response-based treatment, is equally important. Knowledge of these topics will yield both an appreciation of the value of radiation in the combined modality setting and the ability to better customize treatment regimens to individual patients. Copyright © 2015 by the National Comprehensive Cancer Network.

  19. Basal cell carcinoma after radiation therapy

    International Nuclear Information System (INIS)

    Shimbo, Keisuke; Terashi, Hiroto; Ishida, Yasuhisa; Tahara, Shinya; Osaki, Takeo; Nomura, Tadashi; Ejiri, Hirotaka

    2008-01-01

    We reported two cases of basal cell carcinoma (BCC) that developed after radiation therapy. A 50-year-old woman, who had received an unknown amount of radiation therapy for the treatment of intracranial germinoma at the age of 22, presented with several tumors around the radiation ulcer. All tumors showed BCC. A 33-year-old woman, who had received an unknown amount of radiation therapy on the head for the treatment of leukemia at the age of 2, presented with a black nodule within the area of irradiation. The tumor showed BCC. We discuss the occurrence of BCC after radiation therapy. (author)

  20. The position and current status of radiation therapy after primary systemic therapy in breast cancer: a national survey-based expert consensus statement.

    Science.gov (United States)

    Arenas, M; Montero, Á; de Las Peñas, M D; Algara, M

    2016-06-01

    Primary systemic therapy (PST) is changing the role of radiation therapy (RT) in breast cancer. Without randomized studies, the optimal indications for RT after PST and surgery are not clear. The present study provides consensus-based recommendations to clarify the role of RT. Radiation oncologists (n = 82; 77 % response rate) in Spain were surveyed to determine their recommendations for locoregional RT following PST and surgery. Most (98 %) specialists support whole breast irradiation after breast-conserving surgery (BCS), regardless of pathologic response to PST. In T1-T2 and T3-T4 tumours with sentinel node biopsy (SNB) prior to PST, 91 and 56 % of respondents, respectively, recommend irradiating the supraclavicular (level IV) and axillary level III nodes when nodal involvement is detected (9 and 44 % of respondents recommend irradiating these areas by independent of nodal status). If SNB is not available, 57 and 30 % of specialists agreed that the aforementioned nodal regions should be irradiated (33 and 65 % of respondents recommend irradiating these areas by independent of nodal status). Between 58 and 76 % of specialists agreed that nodal levels I and II should be irradiated in cases of insufficient lymphadenectomy or when >75 % of the resected nodes are involved. Agreement is strong regarding the indications for local RT after PST and surgery, but less so for nodal irradiation. All patients who undergo BCS should receive RT, even with complete pathologic response. After mastectomy, RT is recommended in all node-positive stage III cases. Prospective studies will clarify indications for RT in this patient population.

  1. Treatment of dogs with oral melanoma by hypofractionated radiation therapy and platinum-based chemotherapy (1987-1997).

    Science.gov (United States)

    Freeman, Kim P; Hahn, Kevin A; Harris, F Dee; King, Glen K

    2003-01-01

    This retrospective study in 39 dogs with incompletely resected oral melanoma examined the efficacy of hypofractionated radiation therapy and platinum-containing chemotherapy. All dogs were completely staged, with the majority of dogs classified as stage 1. Dogs received 6 weekly fractions of 6-gray (Gy) megavoltage irradiation with a cobalt-60 unit or a 4-MeV (megaelectron volts) linear accelerator. Dogs received cisplatin (10-30 mg/m2 IV) or carboplatin (90 mg/m2 IV) chemotherapy 60 minutes before radiation delivery. Durations of local control, metastasis-free survival time, and overall survival time were recorded. By the Kaplan-Meier method, 15% of the dogs had local recurrence within a median time of 139 days. Fifty-one percent of the dogs developed metastatic disease within a median time of 311 days (range, 24-2, 163 days). Median survival time for all 39 dogs was 363 days. The combined use of chemotherapy and radiation therapy in this protocol provided local control consistent with previous studies. Low-dose chemotherapy was used with the intent of enhancing radiation therapy for the local control of an incompletely excised tumor. Survival times were longer than previously reported for dogs with oral malignant melanoma. Additional studies are required to determine whether these results were due to the effects of chemotherapy on microscopic disease or the enhanced local control provided by chemoradiation therapy.

  2. Radiation therapy of the uterine cancer

    International Nuclear Information System (INIS)

    Noguchi, Hiroshi

    1999-01-01

    Cervical and endometrial cancer of the uterus, and ovarian cancer are three major malignant diseases in gynecology in Japan. These diagnosis and therapy are almost established. In uterine cervical cancer, radiation therapy and surgery of these diseases are two main treatment methods, and both treatment results are almost the same. And radiation therapy is also used as postoperative treatment to patients with high risk factors. In endometrial cancer, surgery is main therapy. Radiation therapy is undergone only to medically inoperable cases preoperative radiation is widely carried out in Europe and America, but almost none in Japan. Postoperative irradiation is adapted to the cases with high risk factors. But recent advance of chemotherapy changes the importance of radiation therapy in such patients. I review the literatures of radiation therapy of uterine cervical cancer and of endometrial cancer. (author)

  3. Radiation therapy in elderly patients

    International Nuclear Information System (INIS)

    Terradas, M.; Santini, A.; Mara, C.

    2004-01-01

    Elderly patients, or those individuals over 65 or 70 depending on the different authors, represent the majority of cancer patients who treated with radiation therapy (RT), however there are very few publications that we provide information needed to evaluate the use of RT in the treatment elders regarding: indication of dose, tissue tolerance, toxicity and association with other therapeutic modalities. In the treatment process must take into account RT radiobiology Clinical applied to each patient and is more relevant in the elderly in which often are comorbid conditions and functional limitations normal tissues increases with age and disease coexisting vascular and connective influencing RT treatment. Chronological age does not correlate with the biological age for tolerance normal tissue, however frequently refers to healthy tissue in the elderly are less tolerant than healthy tissue RT adults young but no data in the literature to support it and perhaps those claims probably based on the presence of comorbid conditions or diseases associated or previous surgeries that influence the risk of tissue damage healthy. Studies conducted by the EORTC not show differences in toxicity acute and late age-related. Elderly patients tolerate RT like younger patients with comparable side effects. In the case of concurrent chronic diseases should take into account a possible modification of the dose and volume irradiated to prevent the risk develop permanent damage or sector body lest un irradiated able to compensate for the loss of function of the irradiated tissue; but we should always note that the dose reduction while reducing the risk of complications also decreases the chance of cure

  4. Radiation therapy system and its accuracy

    International Nuclear Information System (INIS)

    Nakamura, Yuzuru

    1990-01-01

    Three prerequisites for increasing accuracy of radiation therapy are considered. Firstly, every irradiation must be performed without errors according to irradiation conditions. Secondly, accurate quality assurance of equipments for radiation, diagnosis, radiation planning, and dosimetry must be maintained. Thirdly, new radiation planning system and treatment equipments with the introduction of computers are required. The purpose of this report is to discuss accuracy of radiation therapy, focusing on (I) the current status of radiation therapy system developed at the National Institute of Radiation Sciences (NIRS) in Japan and on (II) basic items and quality assurance for increasing accuracy of radiation therapy. Fast neutron therapy has been started with the NIRS cyclotron collimator in November 1975. The advent of X-ray CT has contributed to radiation therapy planning, in that it visualizes the inside structure of the patient stereoscopically. An optical positioning apparatus with CT scanner and a dedicated CT simulator have been developed, allowing the realization of more accurate conformation radiotherapy. Error or uncertainty poses a problem in radiation therapy and treatment system. The ICRU Report 24 describes that standard errors for biological changes in tolerance radiation doses should be within ±5%. The AAPM Report 13 describes that uncertainty for dosimetry with phantoms or dose distribution computation must be less than 2.5% and 4.2%, respectively. It is recommended that quality assurance program be introduced to decrease errors in radiation therapy. (N.K.)

  5. DNA repair related to radiation therapy

    International Nuclear Information System (INIS)

    Klein, W.

    1979-01-01

    The DNA excision repair capacity of peripheral human lymphocytes after radiation therapy has been analyzed. Different forms of application of the radiation during the therapy have been taken into account. No inhibition of repair was found if cells were allowed a certain amount of accomodation to radiation, either by using lower doses or longer application times. (G.G.)

  6. Radiation Therapy After Breast-Conserving Surgery: Does Hospital Surgical Volume Matter? A Population-Based Study in Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Chien, Chun-Ru [Section of Health Services Research, Department of Biostatistics, Division of Quantitative Sciences, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Department of Radiation Oncology, China Medical University Hospital, and School of Medicine, China Medical University, Taichung, Taiwan (China); Pan, I-Wen [Section of Health Services Research, Department of Biostatistics, Division of Quantitative Sciences, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Tsai, Yi-Wen [Center of Health Policy Research and Development, National Health Research Institutes, Miaoli County, Taiwan (China); Institute of Health and Welfare Policy, National Yang-Ming University Hospital, Taipei, Taiwan (China); Tsai, Teressa [Center of Health Policy Research and Development, National Health Research Institutes, Miaoli County, Taiwan (China); Liang, Ji-An [Department of Radiation Oncology, China Medical University Hospital, and School of Medicine, China Medical University, Taichung, Taiwan (China); Buchholz, Thomas A. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Shih, Ya-Chen Tina, E-mail: yashih@mdanderson.org [Section of Health Services Research, Department of Biostatistics, Division of Quantitative Sciences, University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2012-01-01

    Purpose: To examine the association between hospital surgical volume and the use of radiation therapy (RT) after breast-conserving surgery (BCS) in Taiwan. Methods and Materials: We used claims data from the National Health Insurance program in Taiwan (1997-2005) in this retrospective population-based study. We identified patients with breast cancer, receipt of BCS, use of radiation, and the factors that could potentially associated with the use of RT from enrollment records, and the ICD-9 and billing codes in claims. We conducted logistic regression to examine factors associated with RT use after BCS, and performed subgroup analyses to examine whether the association differs by medical center status or hospital volumes. Results: Among 5,094 patients with newly diagnosed invasive breast cancer who underwent BCS, the rate of RT was significantly lower in low-volume hospitals (74% vs. 82%, p < 0.01). Patients treated in low-volume hospitals were less likely to receive RT after BCS (odds ratio = 0.72, 95% confidence interval = 0.62-0.83). In addition, patients treated after the implementation of the voluntary pay-for-performance policy in 2001 were more likely to receive RT (odds ratio = 1.23; 95% confidence interval = 1.05-1.45). Subgroup analyses indicated that the high-volume effect was limited to hospitals accredited as non-medical centers, and that the effect of the pay-for-performance policy was most pronounced among low-volume hospitals. Conclusions: Using population-based data from Taiwan, our study concluded that hospital surgical volume and pay-for-performance policy are positively associated with RT use after BCS.

  7. Radiation therapy of thoracic and abdominal tumors

    International Nuclear Information System (INIS)

    LaRue, S.M.; Gillette, S.M.; Poulson, J.M.

    1995-01-01

    Until recently, radiotherapy of thoracic and abdominal tumors in animals has been limited. However, the availability of computerized tomography and other imaging techniques to aid in determining the extent of tumor, an increase in knowledge of dose tolerance of regional organs, the availability of isocentrically mounted megavoltage machines, and the willingness of patients to pursue more aggressive treatment is making radiation therapy of tumors in these regions far more common. Tumor remission has been reported after radiation therapy of thymomas. Radiation therapy has been used to treat mediastinal lymphoma refractory to chemotherapy, and may be beneficial as part of the initial treatment regimen for this disease. Chemodectomas are responsive to radiation therapy in human patients, and favorable response has also been reported in dogs. Although primary lung tumors in dogs are rare, in some cases radiation therapy could be a useful primary or adjunctive therapy. Lung is the dose-limiting organ in the thorax. Bladder and urethral tumors in dogs have been treated using intraoperative and external-beam radiation therapy combined with chemotherapy. These tumors are difficult to control locally with surgery alone, although the optimal method of combining treatment modalities has not been established. Local control of malignant perianal tumors is also difficult to achieve with surgery alone, and radiation therapy should be used. Intraoperative radiation therapy combined with external-beam radiation therapy has been used for the management of metastatic carcinoma to the sublumbar lymph nodes. Tolerance of retroperitoneal tissues may be decreased by disease or surgical manipulation

  8. Radiation therapy for operable rectal cancer

    International Nuclear Information System (INIS)

    Bondar, G.V.; Semikoz, N.G.; Bashejev, V.Kh.; Borota, O.V.; Bondarenko, M.V.; Kiyashko, O.Yu.

    2012-01-01

    The authors present a review of the literature on modern tendencies of radiation therapy application to treatment of operable rectal cancer. Many randomized control studies compared the efficacy of combination of radiation therapy (pre-operative or post-operative) and surgery versus surgery only demonstrating various results. Meta-analysis of the data on efficacy of combination of radiation therapy and standard surgery revealed 22 randomized control studies (14 with pre-operative radiation therapy and 8 with post-operative radiation therapy) with total number of 8507 patients (Colorectal Cancer Collaborative Group, 2000). The use of combination treatment reduced the number of isolated locoregional relapses both with pre-operative (22.5 - 12.5 %; p < 0.00001) and post-operative radiation therapy (25.8 - 16.7 %; p - 0.00001). The influence on total survival was not significant (62 % vs. 63 %; p - 0.06).

  9. NOTE: Implementation of biologically conformal radiation therapy (BCRT) in an algorithmic segmentation-based inverse planning approach

    Science.gov (United States)

    Vanderstraeten, Barbara; DeGersem, Werner; Duthoy, Wim; DeNeve, Wilfried; Thierens, Hubert

    2006-08-01

    The development of new biological imaging technologies offers the opportunity to further individualize radiotherapy. Biologically conformal radiation therapy (BCRT) implies the use of the spatial distribution of one or more radiobiological parameters to guide the IMRT dose prescription. Our aim was to implement BCRT in an algorithmic segmentation-based planning approach. A biology-based segmentation tool was developed to generate initial beam segments that reflect the biological signal intensity pattern. The weights and shapes of the initial segments are optimized by means of an objective function that minimizes the root mean square deviation between the actual and intended dose values within the PTV. As proof of principle, [18F]FDG-PET-guided BCRT plans for two different levels of dose escalation were created for an oropharyngeal cancer patient. Both plans proved to be dosimetrically feasible without violating the planning constraints for the expanded spinal cord and the contralateral parotid gland as organs at risk. The obtained biological conformity was better for the first (2.5 Gy per fraction) than for the second (3 Gy per fraction) dose escalation level.

  10. Stereotactic body radiation therapy in hepatocellular carcinoma: Optimal treatment strategies based on liver segmentation and functional hepatic reserve.

    Science.gov (United States)

    Wang, Po-Ming; Chung, Na-Na; Hsu, Wei-Chung; Chang, Feng-Ling; Jang, Chin-Jyh; Scorsetti, Marta

    2015-01-01

    To discuss current dosage for stereotactic body radiation therapy (SBRT) in hepatocellular carcinoma (HCC) patients and suggest alternative treatment strategies according to liver segmentation as defined by the Couinaud classification. SBRT is a safe and effective alternative treatment for HCC patients who are unable to undergo liver ablation/resection. However, the SBRT fractionation schemes and treatment planning strategies are not well established. In this article, the latest developments and key findings from research studies exploring the efficacy of SBRT fractionation schemes for treatment of HCC are reviewed. Patients' characteristics, fractionation schemes, treatment outcomes and toxicities were compiled. Special attention was focused on SBRT fractionation approaches that take into consideration liver segmentation according to the Couinaud classification and functional hepatic reserve based on Child-Pugh (CP) liver cirrhosis classification. The most common SBRT fractionation schemes for HCC were 3 × 10-20 Gy, 4-6 × 8-10 Gy, and 10 × 5-5.5 Gy. Based on previous SBRT studies, and in consideration of tumor size and CP classification, we proposed 3 × 15-25 Gy for patients with tumor size 5 cm or CP-B score. Treatment schemes in SBRT for HCC vary according to liver segmentation and functional hepatic reserve. Further prospective studies may be necessary to identify the optimal dose of SBRT for HCC.

  11. EPID-based dosimetry and its relation to other 2D and 3D dose measurement techniques in radiation therapy

    Science.gov (United States)

    Mijnheer, B.

    2017-05-01

    In this paper I will summarize the possibilities and limitations of different 2D and 3D dosimetry techniques used in radiation therapy, and evaluate these features relative to those of EPID-based techniques. After briefly discussing their characteristics, I will review the use of EPIDs for pre-treatment and in vivo dosimetry applications by separating them into transit and non-transit approaches, analysed by either forward- or backward-projection methods. I will then review the various types of 3D dosimetry systems by categorizing them into semi-3D, pseudo-3D, to which EPID-based back-projection approaches belong, and full-3D systems. All methods can in principle be used for pre-treatment 3D dose verification; the choice of a specific system depends on the aim of the measurement and the properties of the specific hard- and software. At this moment EPIDs are the only tools available for 3D in vivo dosimetry. I will conclude with revealing some trends and future developments in 3D pre-treatment and in vivo dosimetry.

  12. Principal component analysis-based anatomical motion models for use in adaptive radiation therapy of head and neck cancer patients

    Science.gov (United States)

    Chetvertkov, Mikhail A.

    Purpose: To develop standard and regularized principal component analysis (PCA) models of anatomical changes from daily cone beam CTs (CBCTs) of head and neck (H&N) patients, assess their potential use in adaptive radiation therapy (ART), and to extract quantitative information for treatment response assessment. Methods: Planning CT (pCT) images of H&N patients were artificially deformed to create "digital phantom" images, which modeled systematic anatomical changes during Radiation Therapy (RT). Artificial deformations closely mirrored patients' actual deformations, and were interpolated to generate 35 synthetic CBCTs, representing evolving anatomy over 35 fractions. Deformation vector fields (DVFs) were acquired between pCT and synthetic CBCTs (i.e., digital phantoms), and between pCT and clinical CBCTs. Patient-specific standard PCA (SPCA) and regularized PCA (RPCA) models were built from these synthetic and clinical DVF sets. Eigenvectors, or eigenDVFs (EDVFs), having the largest eigenvalues were hypothesized to capture the major anatomical deformations during treatment. Modeled anatomies were used to assess the dose deviations with respect to the planned dose distribution. Results: PCA models achieve variable results, depending on the size and location of anatomical change. Random changes prevent or degrade SPCA's ability to detect underlying systematic change. RPCA is able to detect smaller systematic changes against the background of random fraction-to-fraction changes, and is therefore more successful than SPCA at capturing systematic changes early in treatment. SPCA models were less successful at modeling systematic changes in clinical patient images, which contain a wider range of random motion than synthetic CBCTs, while the regularized approach was able to extract major modes of motion. For dose assessment it has been shown that the modeled dose distribution was different from the planned dose for the parotid glands due to their shrinkage and shift into

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

    Science.gov (United States)

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

  14. Radiation therapy of peritoneal mesothelioma

    International Nuclear Information System (INIS)

    Lederman, G.; Recht, A.

    1986-01-01

    The role of radiation therapy in the treatment of peritoneal mesotheliomas remains ill-defined despite its association with the few long-term survivals reported for this disease. The rationale for local therapy is clear as the disease most often is confined to the peritoneal cavity at the time of initial diagnosis and remains there for much of the subsequent course. Effective local treatment of this intra-abdominal disease would likely improve survival. The absence of randomized studies has made analysis of the various treatments of the disease and the few reported success difficult. Nonetheless, scrutiny of the available data may offer insights and guide future clinical trials, as well as the clinician responsible for the treatment of current patients with peritoneal mesothelioma. The radiotherapeutic approach to oncology stresses anatomic considerations in an attempt to understand the patterns of spread of the primary tumor. The observed location and bulk of disease by clinical examination, radiologic study, surgical exploration, and autopsy suggest mechanisms of metastases (direct extension, lymphatic or hematogenous). This dictates the administration of radiation that best achieves a successful outcome

  15. Missed Radiation Therapy and Cancer Recurrence

    Science.gov (United States)

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

  16. Radiation therapy services in South Africa

    African Journals Online (AJOL)

    combined with the components of adequate RT: localis- ing systems (computed tomography (CT) scanners and simulators), planning equipment, radiation machines for both teletherapy and brachytherapy, skilled therapy radiographers, physicists and radiation therapists. A survey was undertaken to determine the adequacy.

  17. Risk analysis of external radiation therapy

    International Nuclear Information System (INIS)

    Arvidsson, Marcus

    2011-09-01

    External radiation therapy is carried out via a complex treatment process in which many different groups of staff work together. Much of the work is dependent on and in collaboration with advanced technical equipment. The purpose of the research task has been to identify a process for external radiation therapy and to identify, test and analyze a suitable method for performing risk analysis of external radiation therapy

  18. Radiation Dose to the Esophagus From Breast Cancer Radiation Therapy, 1943-1996: An International Population-Based Study of 414 Patients

    International Nuclear Information System (INIS)

    Lamart, Stephanie; Stovall, Marilyn; Simon, Steven L.; Smith, Susan A.; Weathers, Rita E.; Howell, Rebecca M.; Curtis, Rochelle E.; Aleman, Berthe M.P.; Travis, Lois; Kwon, Deukwoo; Morton, Lindsay M.

    2013-01-01

    Purpose: To provide dosimetric data for an epidemiologic study on the risk of second primary esophageal cancer among breast cancer survivors, by reconstructing the radiation dose incidentally delivered to the esophagus of 414 women treated with radiation therapy for breast cancer during 1943-1996 in North America and Europe. Methods and Materials: We abstracted the radiation therapy treatment parameters from each patient’s radiation therapy record. Treatment fields included direct chest wall (37% of patients), medial and lateral tangentials (45%), supraclavicular (SCV, 64%), internal mammary (IM, 44%), SCV and IM together (16%), axillary (52%), and breast/chest wall boosts (7%). The beam types used were 60 Co (45% of fields), orthovoltage (33%), megavoltage photons (11%), and electrons (10%). The population median prescribed dose to the target volume ranged from 21 Gy to 40 Gy. We reconstructed the doses over the length of the esophagus using abstracted patient data, water phantom measurements, and a computational model of the human body. Results: Fields that treated the SCV and/or IM lymph nodes were used for 85% of the patients and delivered the highest doses within 3 regions of the esophagus: cervical (population median 38 Gy), upper thoracic (32 Gy), and middle thoracic (25 Gy). Other fields (direct chest wall, tangential, and axillary) contributed substantially lower doses (approximately 2 Gy). The cervical to middle thoracic esophagus received the highest dose because of its close proximity to the SCV and IM fields and less overlying tissue in that part of the chest. The location of the SCV field border relative to the midline was one of the most important determinants of the dose to the esophagus. Conclusions: Breast cancer patients in this study received relatively high incidental radiation therapy doses to the esophagus when the SCV and/or IM lymph nodes were treated, whereas direct chest wall, tangentials, and axillary fields contributed lower doses

  19. Radiation therapy for prostatic cancer

    International Nuclear Information System (INIS)

    Kimura, Akira; Minowada, Shigeru; Tomoishi, Junzo; Kinoshita, Kenji; Matsuda, Tadayoshi

    1983-01-01

    A conformation radiotherapy system with collimators, whose openings can be controlled symmetrically by computerized techniques during rotational irradiation by a linear accelerator, has been developed for routine use in our hospital. Forty-four patients underwent radiation therapy, including this particular modality of radiotherapy, for prostatic cancer during the period of July 1976 through December 1981. Eight patients were classified as stage A, 10 stage B, 10 stage C, and 16 as stage D. Twenty-nine patients underwent conformation radiotherapy, two rotation radiotherapy, eight 2-port opposing technique radiotherapy, one 4-field radiotherapy, and four underwent a combination of 2-port opposing technique and conformation radiotherapy. Transient mild side effects such as diarrhea occurred in seven cases, while severe side effects such as rectal stricture or contracted bladder occurred in three cases. The latter occurred only in one case among 29 of conformation radiotherapy and in two among eight of 2-port opposing technique radiotherapy. The results of the treatment of short intervals in stage B, C, and D are as follows: prostatic size was reduced in 26 cases among 36, serum acid phosphatase level was reduced in 15 among 18 who had showed high acid phosphatase levels before treatment, although almost all cases underwent simultaneous hormonal therapy. The effects of radiotherapy alone were verified in two cases of stage B in which radiotherapy preceded hormonal therapy. Prostatic size and serum acid phosphatase level were reduced by radiotherapy alone. (author)

  20. Evaluation and optimization of the parameters used in multiple-atlas-based segmentation of prostate cancers in radiation therapy.

    Science.gov (United States)

    Wong, Wicger K H; Leung, Lucullus H T; Kwong, Dora L W

    2016-01-01

    To evaluate and optimize the parameters used in multiple-atlas-based segmentation of prostate cancers in radiation therapy. A retrospective study was conducted, and the accuracy of the multiple-atlas-based segmentation was tested on 30 patients. The effect of library size (LS), number of atlases used for contour averaging and the contour averaging strategy were also studied. The autogenerated contours were compared with the manually drawn contours. Dice similarity coefficient (DSC) and Hausdorff distance were used to evaluate the segmentation agreement. Mixed results were found between simultaneous truth and performance level estimation (STAPLE) and majority vote (MV) strategies. Multiple-atlas approaches were relatively insensitive to LS. A LS of ten was adequate, and further increase in the LS only showed insignificant gain. Multiple atlas performed better than single atlas for most of the time. Using more atlases did not guarantee better performance, with five atlases performing better than ten atlases. With our recommended setting, the median DSC for the bladder, rectum, prostate, seminal vesicle and femurs was 0.90, 0.77, 0.84, 0.56 and 0.95, respectively. Our study shows that multiple-atlas-based strategies have better accuracy than single-atlas approach. STAPLE is preferred, and a LS of ten is adequate for prostate cases. Using five atlases for contour averaging is recommended. The contouring accuracy of seminal vesicle still needs improvement, and manual editing is still required for the other structures. This article provides a better understanding of the influence of the parameters used in multiple-atlas-based segmentation of prostate cancers.

  1. Impact of Computed Tomography Image Quality on Image-Guided Radiation Therapy Based on Soft Tissue Registration

    International Nuclear Information System (INIS)

    Morrow, Natalya V.; Lawton, Colleen A.; Qi, X. Sharon; Li, X. Allen

    2012-01-01

    Purpose: In image-guided radiation therapy (IGRT), different computed tomography (CT) modalities with varying image quality are being used to correct for interfractional variations in patient set-up and anatomy changes, thereby reducing clinical target volume to the planning target volume (CTV-to-PTV) margins. We explore how CT image quality affects patient repositioning and CTV-to-PTV margins in soft tissue registration-based IGRT for prostate cancer patients. Methods and Materials: Four CT-based IGRT modalities used for prostate RT were considered in this study: MV fan beam CT (MVFBCT) (Tomotherapy), MV cone beam CT (MVCBCT) (MVision; Siemens), kV fan beam CT (kVFBCT) (CTVision, Siemens), and kV cone beam CT (kVCBCT) (Synergy; Elekta). Daily shifts were determined by manual registration to achieve the best soft tissue agreement. Effect of image quality on patient repositioning was determined by statistical analysis of daily shifts for 136 patients (34 per modality). Inter- and intraobserver variability of soft tissue registration was evaluated based on the registration of a representative scan for each CT modality with its corresponding planning scan. Results: Superior image quality with the kVFBCT resulted in reduced uncertainty in soft tissue registration during IGRT compared with other image modalities for IGRT. The largest interobserver variations of soft tissue registration were 1.1 mm, 2.5 mm, 2.6 mm, and 3.2 mm for kVFBCT, kVCBCT, MVFBCT, and MVCBCT, respectively. Conclusions: Image quality adversely affects the reproducibility of soft tissue-based registration for IGRT and necessitates a careful consideration of residual uncertainties in determining different CTV-to-PTV margins for IGRT using different image modalities.

  2. Providing guidance for genomics-based cancer treatment decisions: insights from stakeholder engagement for post-prostatectomy radiation therapy.

    Science.gov (United States)

    Abe, James; Lobo, Jennifer M; Trifiletti, Daniel M; Showalter, Timothy N

    2017-08-24

    Despite the emergence of genomics-based risk prediction tools in oncology, there is not yet an established framework for communication of test results to cancer patients to support shared decision-making. We report findings from a stakeholder engagement program that aimed to develop a framework for using Markov models with individualized model inputs, including genomics-based estimates of cancer recurrence probability, to generate personalized decision aids for prostate cancer patients faced with radiation therapy treatment decisions after prostatectomy. We engaged a total of 22 stakeholders, including: prostate cancer patients, urological surgeons, radiation oncologists, genomic testing industry representatives, and biomedical informatics faculty. Slides were at each meeting to provide background information regarding the analytical framework. Participants were invited to provide feedback during the meeting, including revising the overall project aims. Stakeholder meeting content was reviewed and summarized by stakeholder group and by theme. The majority of stakeholder suggestions focused on aspects of decision aid design and formatting. Stakeholders were enthusiastic about the potential value of using decision analysis modeling with personalized model inputs for cancer recurrence risk, as well as competing risks from age and comorbidities, to generate a patient-centered tool to assist decision-making. Stakeholders did not view privacy considerations as a major barrier to the proposed decision aid program. A common theme was that decision aids should be portable across multiple platforms (electronic and paper), should allow for interaction by the user to adjust model inputs iteratively, and available to patients both before and during consult appointments. Emphasis was placed on the challenge of explaining the model's composite result of quality-adjusted life years. A range of stakeholders provided valuable insights regarding the design of a personalized decision

  3. Gemcitabine-Based Combination Chemotherapy Followed by Radiation With Capecitabine as Adjuvant Therapy for Resected Pancreas Cancer

    International Nuclear Information System (INIS)

    Desai, Sameer; Ben-Josef, Edgar; Griffith, Kent A.; Simeone, Diane; Greenson, Joel K.; Francis, Isaac R.; Hampton, Janet; Colletti, Lisa; Chang, Alfred E.; Lawrence, Theodore S.; Zalupski, Mark M.

    2009-01-01

    Purpose: To report outcomes for patients with resected pancreas cancer treated with an adjuvant regimen consisting of gemcitabine-based combination chemotherapy followed by capecitabine and radiation. Patients and Methods: We performed a retrospective review of a series of patients treated at a single institution with a common postoperative adjuvant program. Between January 2002 and August 2006, 43 resected pancreas cancer patients were offered treatment consisting of 4, 21-day cycles of gemcitabine 1 g/m 2 intravenously over 30 min on Days 1 and 8, with either cisplatin 35 mg/m 2 intravenously on Days 1 and 8 or capecitabine 1500 mg/m 2 orally in divided doses on Days 1-14. After completion of combination chemotherapy, patients received a course of radiotherapy (54 Gy) with concurrent capecitabine (1330 mg/m 2 orally in divided doses) day 1 to treatment completion. Results: Forty-one patients were treated. Median progression-free survival for the entire group was 21.7 months (95% confidence interval 13.9-34.5 months), and median overall survival was 45.9 months. In multivariate analysis a postoperative CA 19-9 level of ≥180 U/mL predicted relapse and death. Toxicity was mild, with only two hospitalizations during adjuvant therapy. Conclusions: A postoperative adjuvant program using combination chemotherapy with gemcitabine and either cisplatin or capecitabine followed by radiotherapy with capecitabine is tolerable and efficacious and should be considered for Phase III testing in this group of patients.

  4. Radiation therapy sources, equipment and installations

    International Nuclear Information System (INIS)

    2011-03-01

    The safety code for Telegamma Therapy Equipment and Installations, (AERB/SC/MED-1) and safety code for Brachytherapy Sources, Equipment and Installations, (AERB/SC/MED-3) were issued by AERB in 1986 and 1988 respectively. These codes specified mandatory requirements for radiation therapy facilities, covering the entire spectrum of operations ranging from the setting up of a facility to its ultimate decommissioning, including procedures to be followed during emergency situations. The codes also stipulated requirements of personnel and their responsibilities. With the advent of new techniques and equipment such as 3D-conformal radiation therapy, intensity modulated radiation therapy, image guided radiation therapy, treatment planning system, stereotactic radiosurgery, stereotactic radiotherapy, portal imaging, integrated brachytherapy and endovascular brachytherapy during the last two decades, AERB desires that these codes be revised and merged into a single code titled Radiation Therapy Sources, Equipment, and Installations

  5. Online model checking for monitoring surrogate-based respiratory motion tracking in radiation therapy.

    Science.gov (United States)

    Antoni, Sven-Thomas; Rinast, Jonas; Ma, Xintao; Schupp, Sibylle; Schlaefer, Alexander

    2016-11-01

    Correlation between internal and external motion is critical for respiratory motion compensation in radiosurgery. Artifacts like coughing, sneezing or yawning or changes in the breathing pattern can lead to misalignment between beam and tumor and need to be detected to interrupt the treatment. We propose online model checking (OMC), a model-based verification approach from the field of formal methods, to verify that the breathing motion is regular and the correlation holds. We demonstrate that OMC may be more suitable for artifact detection than the prediction error. We established a sinusoidal model to apply OMC to the verification of respiratory motion. The method was parameterized to detect deviations from typical breathing motion. We analyzed the performance on synthetic data and on clinical episodes showing large correlation error. In comparison, we considered the prediction error of different state-of-the-art methods based on least mean squares (LMS; normalized LMS, nLMS; wavelet-based multiscale autoregression, wLMS), recursive least squares (RLSpred) and support vector regression (SVRpred). On synthetic data, OMC outperformed wLMS by at least 30 % and SVRpred by at least 141 %, detecting 70 % of transitions. No artifacts were detected by nLMS and RLSpred. On patient data, OMC detected 23-49 % of the episodes correctly, outperforming nLMS, wLMS, RLSpred and SVRpred by up to 544, 491, 408 and 258 %, respectively. On selected episodes, OMC detected up to 94 % of all events. OMC is able to detect changes in breathing as well as artifacts which previously would have gone undetected, outperforming prediction error-based detection. Synthetic data analysis supports the assumption that prediction is very insensitive to specific changes in breathing. We suggest using OMC as an additional safety measure ensuring reliable and fast stopping of irradiation.

  6. Melioidosis: reactivation during radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-05-01

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

  7. Melioidosis: reactivation during radiation therapy

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  8. Installation and testing of a hospital-based cyclotron for radiation therapy and isotope production

    International Nuclear Information System (INIS)

    Almond, P.R.; Marbach, J.R.; Otte, V.A.

    1983-01-01

    A hospital based cyclotron is under installation at The University of Texas M.D. Anderson Hospital in Houston. This machine will be used for the production of radioactive isotopes and for the generation of neutrons for the radiotherapy treatment of cancer. It is a Cyclotron Corporation CP-42 negative proton accelerator. For neutron production the protons are transported through an isocentrically mounted beam transport system that can be rotated around the patient. The shielding requirements of this facility will be described as will the initial measurements on the characteristics of the neutron beam

  9. The carcinogenicity of radiation therapy

    International Nuclear Information System (INIS)

    Pizzarello, D.J.; Roses, D.F.; Newall, J.; Barish, R.J.

    1984-01-01

    Ionizing radiation as used for therapy for cancer is probably weakly carcinogenic at worst. The probability that cancers will be induced at a distance from the treatment volume is so small that it can only be inferred from experiences with large populations exposed to much higher radiation doses. The risk of cancer in and adjacent to the treatment volume also appears to be small, especially in adults. Intensive radiotherapy or radiotherapy of children 20 to 30 years ago appears to have induced secondary cancers in about 3 to 4 per cent of those treated, but modern practice has every expectation of reducing this incidence. No precise risk factor can be offered, but it seems likely that less than 3 to 4 per cent is a reasonable projection. The reason for the low carcinogenicity in the treatment volume probably lies in the fact that the irradiation dose is high and many cells are killed rather than transformed. The frequency of the induction of radiogenic cancer adjacent to or near the treatment volume is expected to vary according to the tissue exposed. It is not estimated to exceed a few per cent in the worst instances (for example, breast and thyroid gland) and is much less than 1 per cent in most tissues

  10. Targeted drugs in radiation therapy

    International Nuclear Information System (INIS)

    Favaudon, V.; Hennequin, C.; Hennequin, C.

    2004-01-01

    New drugs aiming at the development of targeted therapies have been assayed in combination with ionizing radiation over the past few years. The rationale of this concept comes from the fact that the cytotoxic potential of targeted drugs is limited, thus requiring concomitant association with a cytotoxic agent for the eradication of tumor cells. Conversely a low level of cumulative toxicity is expected from targeted drugs. Most targeted drugs act through inhibition of post-translational modifications of proteins, such as dimerization of growth factor receptors, prenylation reactions, or phosphorylation of tyrosine or serine-threonine residues. Many systems involving the proteasome, neo-angiogenesis promoters, TGF-β, cyclooxygenase or the transcription factor NF-κB, are currently under investigation in hopes they will allow a control of cell proliferation, apoptosis, cell cycle progression, tumor angiogenesis and inflammation. A few drugs have demonstrated an antitumor potential in particular phenotypes. In most instances, however, radiation-drug interactions proved to be strictly additive in terms of cell growth inhibition or induced cell death. Strong potentiation of the response to radiotherapy is expected to require interaction with DNA repair mechanisms. (authors)

  11. Nonsurgical treatment for cancer using radiation therapy

    International Nuclear Information System (INIS)

    Ogi, Yasuo

    2012-01-01

    The number of people who are dying from cancer has been increasing in association with population aging. Radiation therapy is now one of the three major cancer treatment methods, along with surgery and chemotherapy. People used to consider radiation therapy only as a ''noninvasive cancer treatment''; however, with the ceaseless effort by medical experts and corporations, different radiation therapy types and techniques including the latest technical advances have come out one after another, and the improvements in radiation therapies have provided treatments that are not only less traumatizing to patients but also as effective and therapeutic as surgery in certain body regions. The importance of radiation therapy has become and will become even greater in the society with more elderly cancer patients who do not have the physical strength to undergo surgery. In this article, the history of radiation therapy, rapidly developed high-precision radiation therapy techniques, and unsolved issues are discussed, and then, ''MHI vero4DRT'', which is the high-precision image-guided radiation therapy equipment developed for solving such issues, is introduced. (author)

  12. Radiation-Induced Peripheral Malignant Nerve Sheath Tumor Arising from Vestibular Schwannoma after Linac-Based Stereotactic Radiation Therapy: A Case Report and Review of Literatures

    Directory of Open Access Journals (Sweden)

    Putipun Puataweepong

    2012-01-01

    Full Text Available In recent years the use of stereotactic radiation for vestibular schwannomas has increased worldwide. However, malignant transformation associated with radiation, although uncommon, has been reported in recent publications. We present a case of the 34 year-old female who had left vestibular schwannoma and who underwent surgery and postoperative stereotactic radiotherapy (SRT, hypofraction in 2005. At 6 years after SRT, the patient came with left facial palsy and severe headache. CT brain revealed progression in size with cystic and hemorrhagic changes of the preexisting tumor at left CPA with new obstructive hydrocephalus. Partial tumor removal was done, and the pathological report was malignant peripheral nerve sheath tumor (MPNST. Regarding the uncertainty of carcinogenesis risk, we should still practice radiation therapy with caution, especially in the young patient with tumor predisposition syndrome. Because of low incidence of MPNST after radiation, it should not be a major decision about giving radiotherapy. However, with the poor prognosis of MPNST, this possibility should be explained to the patient before radiation treatment option.

  13. Radiation therapy facilities in the United States

    International Nuclear Information System (INIS)

    Ballas, Leslie K.; Elkin, Elena B.; Schrag, Deborah; Minsky, Bruce D.; Bach, Peter B.

    2006-01-01

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

  14. Fiber-optic dosimeters for radiation therapy

    Science.gov (United States)

    Li, Enbang; Archer, James

    2017-10-01

    According to the figures provided by the World Health Organization, cancer is a leading cause of death worldwide, accounting for 8.8 million deaths in 2015. Radiation therapy, which uses x-rays to destroy or injure cancer cells, has become one of the most important modalities to treat the primary cancer or advanced cancer. The newly developed microbeam radiation therapy (MRT), which uses highly collimated, quasi-parallel arrays of x-ray microbeams (typically 50 μm wide and separated by 400 μm) produced by synchrotron sources, represents a new paradigm in radiotherapy and has shown great promise in pre-clinical studies on different animal models. Measurements of the absorbed dose distribution of microbeams are vitally important for clinical acceptance of MRT and for developing quality assurance systems for MRT, hence are a challenging and important task for radiation dosimetry. On the other hand, during the traditional LINAC based radiotherapy and breast cancer brachytherapy, skin dose measurements and treatment planning also require a high spatial resolution, tissue equivalent, on-line dosimeter that is both economical and highly reliable. Such a dosimeter currently does not exist and remains a challenge in the development of radiation dosimetry. High resolution, water equivalent, optical and passive x-ray dosimeters have been developed and constructed by using plastic scintillators and optical fibers. The dosimeters have peak edge-on spatial resolutions ranging from 50 to 500 microns in one dimension, with a 10 micron resolution dosimeter under development. The developed fiber-optic dosimeters have been test with both LINAC and synchrotron x-ray beams. This work demonstrates that water-equivalent and high spatial resolution radiation detection can be achieved with scintillators and optical fiber systems. Among other advantages, the developed fiber-optic probes are also passive, energy independent, and radiation hard.

  15. nano-particles in radiation therapy

    International Nuclear Information System (INIS)

    Billotey, Claire; Bourhis, Jean; Levy, Laurent

    2012-01-01

    After a recall of the history of radiation therapy this article outlines that the presence of a high electronic density material within a tumour can artificially and locally increase the radiation absorption. It outlines the benefit of the elaboration of nano-particles from such a material for the case of external radiation therapy (increase of material density and bioavailability of nano-particles) where nano-particles can even be introduced by intravenous injection. It describes the various possibility of using nano-particles in the case of internal radiation therapy or Curie therapy. It allows a much less invasive process, the possibility of direct injection into a tumour or a cavity, and the possibility of an increase of the dose received by cells. Other topics are briefly evoked: subcellular targeting by high atomic number nano-particles, and the radiation therapy approach by Nanobiotix

  16. Automatic Organ Localization for Adaptive Radiation Therapy for Prostate Cancer

    National Research Council Canada - National Science Library

    Joshi, Sarang

    2004-01-01

    The focus of this study is adaptive radiation therapy (ART) for prostate cancer, in which the treatment is to be adjusted over time, based on CT images acquired on the treatment table before each daily treatment...

  17. Internal radiation dosimetry in radionuclide therapy

    International Nuclear Information System (INIS)

    Kim, Kyeong Min; Lim, Sang Moo

    2006-01-01

    Radionuclide therapy has been continued for treatment of incurable diseases for past decades. Relevant evaluation of absorbed dose in radionuclide therapy in important to predict treatment output and essential for making treatment planning to prevent unexpected radiation toxicity. Many scientists in the field related with nuclear medicine have made effort to evolve concept and technique for internal radiation dosimetry. In this review, basic concept of internal radiation dosimetry if described and recent progress in method for dosimetry is introduced

  18. Risk management of radiation therapy. Survey by north Japan radiation therapy oncology group

    International Nuclear Information System (INIS)

    Aoki, Masahiko; Abe, Yoshinao; Yamada, Shogo; Hareyama, Masato; Nakamura, Ryuji; Sugita, Tadashi; Miyano, Takashi

    2004-01-01

    A North Japan Radiation Oncology Group (NJRTOG) survey was carried out to disclose the risk management of radiation therapy. During April 2002, we sent questionnaires to radiation therapy facilities in northern Japan. There were 31 replies from 27 facilities. Many incidents and accidents were reported, including old cases. Although 60% of facilities had a risk management manual and/or risk manager, only 20% had risk management manuals for radiation therapy. Eighty five percent of radiation oncologists thought that incidents may be due to a lack of manpower. Ninety percent of radiation oncologists want to know the type of cases happened in other facilities. The risk management system is still insufficient for radiation therapy. We hope that our data will be a great help to develop risk management strategies for radiation therapy for all radiation oncologists in Japan. (author)

  19. TOPOS: a new topometric patient positioning and tracking system for radiation therapy based on structured white light.

    Science.gov (United States)

    Lindl, Bastian L; Müller, Reinhold G; Lang, Stephanie; Herraiz Lablanca, Maria D; Klöck, Stephan

    2013-04-01

    A patient positioning system for radiation therapy based on structured white light and using off-the-shelf hardware components for flexibility and cost-effectiveness has been developed in house. Increased accuracy, patient comfort, abandonment of any skin marks, accelerated workflow, objective reading/recording, better usability and robust sensor design, compared to other positioning approaches, were the main goals of this work. Another aim was the application of a 6 degrees of freedom tracking system working without dose deposition. Two optical sensors are the main parts of the TOPOS® system (Topometrical Positioning, cyberTECHNOLOGIES, Germany). The components: cameras, projectors, and computers are commercial off-the-shelf products, allowing for low production costs. The black/white cameras of the prototype are capable of taking up to 240 frames per second (resolution: 640 × 488 pixels). The projector has a resolution of 1024 × 768 and a refresh rate of 120 Hz. The patient's body surface is measured continuously and registered to a reference surface, providing a transformation to superimpose the patient's surface to the reference (planning CT) surface as best as possible. The execution of the calculated transformation provides the correct patient position before the treatment starts. Due to the high-speed acquisition of the surfaces, a surveillance of the patient's (respiration) motion during treatment is also accomplished. The accuracy of the system was determined using a male mannequin. Two treatment sites were evaluated: one simulating a head and neck treatment and the other simulating a thoracic wall treatment. The mannequin was moved to predefined positions, and shift vectors given by the surface registration were evaluated. Additionally manual positioning using a color-coding system was evaluated. Two prototypes have been developed, each allowing a continuous high density scan of a 500 × 500 × 400 mm(3) (L × W × D) large volume with a refresh rate

  20. Imaging after radiation therapy of thoracic tumors

    International Nuclear Information System (INIS)

    Ghaye, B.; Wanet, M.; El Hajjam, M.

    2016-01-01

    Radiation-induced lung disease (RILD) is frequent after therapeutic irradiation of thoracic malignancies. Many technique-, treatment-, tumor- and patient-related factors influence the degree of injury sustained by the lung after irradiation. Based on the time interval after the completion of the treatment RILD presents as early and late features characterized by inflammatory and fibrotic changes, respectively. They are usually confined to the radiation port. Though the typical pattern of RILD is easily recognized after conventional two-dimensional radiation therapy (RT), RILD may present with atypical patterns after more recent types of three or four-dimensional RT treatment. Three atypical patterns are reported: the modified conventional, the mass-like and the scar-like patterns. Knowledge of the various features and patterns of RILD is important for correct diagnosis and appropriate treatment. RILD should be differentiated from recurrent tumoral disease, infection and radiation-induced tumors. Due to RILD, the follow-up after RT may be difficult as response evaluation criteria in solid tumours (RECIST) criteria may be unreliable to assess tumor control particularly after stereotactic ablation RT (SABR). Long-term follow-up should be based on clinical examination and morphological and/or functional investigations including CT, PET-CT, pulmonary functional tests, MRI and PET-MRI. (authors)

  1. Multiscale registration of medical images based on edge preserving scale space with application in image-guided radiation therapy

    Science.gov (United States)

    Li, Dengwang; Li, Hongsheng; Wan, Honglin; Chen, Jinhu; Gong, Guanzhong; Wang, Hongjun; Wang, Liming; Yin, Yong

    2012-08-01

    gross tumor volume re-contouring for clinical PET/CT image-guided radiation therapy throughout the course of radiotherapy is also studied, and the overlap between the automatically generated contours for the CT image and the contours delineated by the oncologist used for the planning system are on average 90%.

  2. PET/CT-guided dose-painting versus CT-based intensity modulated radiation therapy in locoregional advanced nasopharyngeal carcinoma.

    Science.gov (United States)

    Liu, Feng; Xi, Xu-Ping; Wang, Hui; Han, Ya-Qian; Xiao, Feng; Hu, Ying; He, Qian; Zhang, Lin; Xiao, Qin; Liu, Lin; Luo, Le; Li, Yun; Mo, Yi; Ma, Hong-Zhi

    2017-01-13

    The effect of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT)-guided dose-painting intensity-modulated radiation therapy (IMRT) in locoregionally advanced nasopharyngeal carcinoma (NPC) is unclear. This study aimed to assess the efficacy and toxicity of such combination. From 2012 to 2014, 213 patients with stage III-IVB NPC received chemoradiotherapy by PET/CT-guided DP-IMRT (group A, n = 101) or CT-based IMRT (group B, n = 112). In group A, subvolume GTVnx- PET (gross tumor volume of nasopharynx in PET images) was defined within GTVnx (gross tumor volume of nasopharynx) as the SUV50%max isocontour; the dose to GTVnx- PET was escalated to DT 75.2 Gy/32 and 77.55 Gy/33 Fx, respectively, for patients with T1-2 and T3-4 disease, respectively. In group B, PGTVnx was irradiated at DT 70.4-72.6 Gy/32-33 Fx in 2.2 Gy per fraction. Complete response rates were 99.0% (100/101) and 92.9% (104/112) in groups A and B, respectively (P = 0.037). Compared with CT-based IMRT, FDG-PET/CT guided DP-IMRT significantly improved 3-year local failure-free survival (LFFS, 98.8% vs. 91.3%; P = 0.032), locoregional failure-free survival (LRFFS, 97.2 vs. 91.2%; P = 0.049), distant metastasis-free survival (DMFS, 92.9% vs. 87.4%; P = 0.041), disease free survival (DFS, 87.9% vs. 82.4%; P = 0.02), and overall survival (OS, 91.8% vs. 82.6%; P = 0.049). No statistically significant differences in acute and late toxic effects were observed. Multivariate analysis showed that dose painting (PET/CT-guided DP-IMRT vs CT-based IMRT without DP) was a significant independent prognostic factor for LFFS and DFS. FDG-PET/CT guided DP-IMRT plus chemotherapy is associated with a considerable survival benefit, without increasing toxicity in patients with locoregional advanced NPC. Further randomized trials are needed to fully assess the role of PET/CT-guided DP-IMRT.

  3. Multiscale registration of medical images based on edge preserving scale space with application in image-guided radiation therapy

    International Nuclear Information System (INIS)

    Li Dengwang; Wan Honglin; Li Hongsheng; Chen Jinhu; Gong Guanzhong; Yin Yong; Wang Hongjun; Wang Liming

    2012-01-01

    adaptive gross tumor volume re-contouring for clinical PET/CT image-guided radiation therapy throughout the course of radiotherapy is also studied, and the overlap between the automatically generated contours for the CT image and the contours delineated by the oncologist used for the planning system are on average 90%. (paper)

  4. Study on external beam radiation therapy

    International Nuclear Information System (INIS)

    Kim, Mi Sook; Yoo, Seoung Yul; Yoo, Hyung Jun; Ji, Young Hoon; Lee, Dong Han; Lee, Dong Hoon; Choi, Mun Sik; Yoo, Dae Heon; Lee, Hyo Nam; Kim, Kyeoung Jung

    1999-04-01

    To develop the therapy technique which promote accuracy and convenience in external radiation therapy, to obtain the development of clinical treatment methods for the global competition. The contents of the R and D were 1. structure, process and outcome analysis in radiation therapy department. 2. Development of multimodality treatment in radiation therapy 3. Development of computation using networking techniques 4. Development of quality assurance (QA) system in radiation therapy 5. Development of radiotherapy tools 6. Development of intraoperative radiation therapy (IORT) tools. The results of the R and D were 1. completion of survey and analysis about Korea radiation therapy status 2. Performing QA analysis about ICR on cervix cancer 3. Trial of multicenter randomized study on lung cancers 4. Setting up inter-departmental LAN using MS NT server and Notes program 5. Development of ionization chamber and dose-rate meter for QA in linear accelerator 6. Development on optimized radiation distribution algorithm for multiple slice 7. Implementation on 3 dimensional volume surface algorithm and 8. Implementation on adaptor and cone for IORT

  5. Study on external beam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Sook; Yoo, Seoung Yul; Yoo, Hyung Jun; Ji, Young Hoon; Lee, Dong Han; Lee, Dong Hoon; Choi, Mun Sik; Yoo, Dae Heon; Lee, Hyo Nam; Kim, Kyeoung Jung

    1999-04-01

    To develop the therapy technique which promote accuracy and convenience in external radiation therapy, to obtain the development of clinical treatment methods for the global competition. The contents of the R and D were 1. structure, process and outcome analysis in radiation therapy department. 2. Development of multimodality treatment in radiation therapy 3. Development of computation using networking techniques 4. Development of quality assurance (QA) system in radiation therapy 5. Development of radiotherapy tools 6. Development of intraoperative radiation therapy (IORT) tools. The results of the R and D were 1. completion of survey and analysis about Korea radiation therapy status 2. Performing QA analysis about ICR on cervix cancer 3. Trial of multicenter randomized study on lung cancers 4. Setting up inter-departmental LAN using MS NT server and Notes program 5. Development of ionization chamber and dose-rate meter for QA in linear accelerator 6. Development on optimized radiation distribution algorithm for multiple slice 7. Implementation on 3 dimensional volume surface algorithm and 8. Implementation on adaptor and cone for IORT.

  6. SU-E-T-64: CG-Based Radiation Therapy Simulator with Physical Modeling for Avoidance of Collisions Between Gantry and Couch Or Patient

    International Nuclear Information System (INIS)

    Yamanouchi, M; Arimura, H; Yuda, I

    2014-01-01

    Purpose: It is time-consuming and might cause re-planning to check couch-gantry and patient-gantry collisions on a radiotherapy machine when using couch rotations for non-coplanar beam angles. The aim of this study was to develop a computer-graphics (CG)-based radiation therapy simulator with physical modeling for avoidance of collisions between gantry and couch or patient on a radiotherapy machine. Methods: The radiation therapy simulator was three-dimensionally constructed including a radiotherapy machine (Clinac iX, Varian Medical Systems), couch, and radiation treatment room according to their designs by using a physical-modeling-based computer graphics software (Blender, free and open-source). Each patient was modeled by applying a surface rendering technique to their planning computed tomography (CT) images acquired from 16-slice CT scanner (BrightSpeed, GE Healthcare). Immobilization devices for patients were scanned by the CT equipment, and were rendered as the patient planning CT images. The errors in the collision angle of the gantry with the couch or patient between gold standards and the estimated values were obtained by fixing the gantry angle for the evaluation of the proposed simulator. Results: The average error of estimated collision angles to the couch head side was -8.5% for gantry angles of 60 to 135 degree, and -5.5% for gantry angles of 225 to 300 degree. Moreover, the average error of estimated collision angles to the couch foot side was -1.1% for gantry angles of 60 to 135 degree, and 1.4% for gantry angles of 225 to 300 degree. Conclusion: The CG-based radiation therapy simulator could make it possible to estimate the collision angle between gantry and couch or patient on the radiotherapy machine without verifying the collision angles in the radiation treatment room

  7. Cardiovascular effects of radiation therapy

    International Nuclear Information System (INIS)

    Alvarez, Jose A.G.; Leiva, Gustavo

    2001-01-01

    Therapeutic mediastinal irradiation can induce heart disease with variable degree of cardiac engagement. Heart disease manifestations depend on the grade of involvement of the different cardiac structures. During the first two years following irradiation, pericarditis with or without pericardial effusion is the most common manifestation of toxicity related to radiation therapy. Later on, after a latency period of five to ten years, a constrictive pericarditis may develop. Other type of late cardiac toxicities due to irradiation are restrictive cardiomyopathy, multiple valvular disease, coronary artery disease and different atrioventricular conduction disturbances. The therapeutic approach to this kind of heart disease has to be focused on its progressive course and in the possibility of a global involvement of all the cardiac structures. Pericardiectomy is strongly recommended for recurrent pericardial effusion with cardiac tamponade. Cardiac surgery for myocardial revascularization or valvular disease can be performed with variable results; the presence of myocardial fibrosis can significantly affect perioperative management and long-term results. Cardiac transplantation is a promissory option for those patients with end-stage cardiac failure. Immunosuppressive regimens are not associated with recurrence of malignancy. (author) [es

  8. Better Efficacy of Synchrotron Spatially Microfractionated Radiation Therapy Than Uniform Radiation Therapy on Glioma

    Energy Technology Data Exchange (ETDEWEB)

    Bouchet, Audrey, E-mail: audrey.m.bouchet@gmail.com [Université Grenoble Alpes, Grenoble Institut des Neurosciences, Grenoble (France); Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble (France); Bräuer-Krisch, Elke; Prezado, Yolanda [Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble (France); El Atifi, Michèle [Université Grenoble Alpes, Grenoble Institut des Neurosciences, Grenoble (France); Grenoble University Hospital, Grenoble (France); Rogalev, Léonid; Le Clec' h, Céline [Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble (France); Laissue, Jean Albert [University of Bern, Bern (Switzerland); Pelletier, Laurent, E-mail: laurent.pelletier@ujf-grenoble.fr [Université Grenoble Alpes, Grenoble Institut des Neurosciences, Grenoble (France); Grenoble University Hospital, Grenoble (France); Le Duc, Géraldine [Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble (France)

    2016-08-01

    Purpose: Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incident, highly focused synchrotron beam into arrays of parallel microbeams, typically a few tens of microns wide and depositing several hundred grays. This irradiation modality was shown to have a high therapeutic impact on tumors, especially in intracranial locations. However, mechanisms responsible for such a property are not fully understood. Methods and Materials: Thanks to recent progress in dosimetry, we compared the effect of MRT and synchrotron broad beam (BB) radiation therapy delivered at comparable doses (equivalent to MRT valley dose) on tumor growth control and on classical radiobiological functions by histologic evaluation and/or transcriptomic analysis. Results: MRT significantly improved survival of rats bearing 9L intracranial glioma compared with BB radiation therapy delivered at a comparable dose (P<.001); the efficacy of MRT and BB radiation therapy was similar when the MRT dose was half that of BB. The greater efficacy of MRT was not correlated with a difference in cell proliferation (Mki67 and proliferating cell nuclear antigen) or in transcriptomic stimulation of angiogenesis (vascular endothelial growth factor A or tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 2) but was correlated with a higher cell death rate (factor for apoptosis signals) and higher recruitment of macrophages (tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 1 and CD68 transcripts) a few days after MRT. Conclusions: These results show the superiority of MRT over BB radiation therapy when applied at comparable doses, suggesting that spatial fractionation is responsible for a specific and particularly efficient tissue response. The higher induction of cell death and immune cell activation in brain tumors treated by MRT may be involved in such responses.

  9. Better Efficacy of Synchrotron Spatially Microfractionated Radiation Therapy Than Uniform Radiation Therapy on Glioma

    International Nuclear Information System (INIS)

    Bouchet, Audrey; Bräuer-Krisch, Elke; Prezado, Yolanda; El Atifi, Michèle; Rogalev, Léonid; Le Clec'h, Céline; Laissue, Jean Albert; Pelletier, Laurent; Le Duc, Géraldine

    2016-01-01

    Purpose: Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incident, highly focused synchrotron beam into arrays of parallel microbeams, typically a few tens of microns wide and depositing several hundred grays. This irradiation modality was shown to have a high therapeutic impact on tumors, especially in intracranial locations. However, mechanisms responsible for such a property are not fully understood. Methods and Materials: Thanks to recent progress in dosimetry, we compared the effect of MRT and synchrotron broad beam (BB) radiation therapy delivered at comparable doses (equivalent to MRT valley dose) on tumor growth control and on classical radiobiological functions by histologic evaluation and/or transcriptomic analysis. Results: MRT significantly improved survival of rats bearing 9L intracranial glioma compared with BB radiation therapy delivered at a comparable dose (P<.001); the efficacy of MRT and BB radiation therapy was similar when the MRT dose was half that of BB. The greater efficacy of MRT was not correlated with a difference in cell proliferation (Mki67 and proliferating cell nuclear antigen) or in transcriptomic stimulation of angiogenesis (vascular endothelial growth factor A or tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 2) but was correlated with a higher cell death rate (factor for apoptosis signals) and higher recruitment of macrophages (tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 1 and CD68 transcripts) a few days after MRT. Conclusions: These results show the superiority of MRT over BB radiation therapy when applied at comparable doses, suggesting that spatial fractionation is responsible for a specific and particularly efficient tissue response. The higher induction of cell death and immune cell activation in brain tumors treated by MRT may be involved in such responses.

  10. Extramammary Paget's disease: role of radiation therapy

    International Nuclear Information System (INIS)

    Guerrieri, M.; Back, M.F.

    2002-01-01

    Extra mammary Paget's disease (EMPD) is an uncommon premalignant skin condition that has been traditionally managed with surgery. A report of long-standing Paget's disease with transformation to invasive adenocarcinoma definitively managed with radiation therapy is presented. A review of cases of extramammary Paget's disease treated with radiation therapy is discussed. The use of radiation therapy should be considered in selected cases, as these studies demonstrate acceptable rates of local control when used as an adjunct to surgery, or as a definitive treatment modality. Copyright (2002) Blackwell Science Pty Ltd

  11. Development of a new prior knowledge based image reconstruction algorithm for the cone-beam-CT in radiation therapy

    International Nuclear Information System (INIS)

    Vaegler, Sven

    2016-01-01

    The treatment of cancer in radiation therapy is achievable today by techniques that enable highly conformal dose distributions and steep dose gradients. In order to avoid mistreatment, these irradiation techniques have necessitated enhanced patient localization techniques. With an integrated x-ray tube at modern linear accelerators kV-projections can be acquired over a sufficiently large angular space and can be reconstructed to a volumetric image data set from the current situation of the patient prior to irradiation. The so-called Cone-Beam-CT (CBCT) allows a precise verification of patient positioning as well as adaptive radiotherapy. The benefits of an improved patient positioning due to a daily performed CBCT's is contrary to an increased and not negligible radiation exposure of the patient. In order to decrease the radiation exposure, substantial research effort is focused on various dose reduction strategies. Prominent strategies are the decrease of the charge per projection, the reduction of the number of projections as well as the reduction of the acquisition space. Unfortunately, these acquisition schemes lead to images with degraded quality with the widely used Feldkamp-Davis-Kress image reconstruction algorithm. More sophisticated image reconstruction techniques can deal with these dose-reduction strategies without degrading the image quality. A frequently investigated method is the image reconstruction by minimizing the total variation (TV), which is also known as Compressed Sensing (CS). A Compressed Sensing-based reconstruction framework that includes prior images into the reconstruction algorithm is the Prior-Image-Constrained- Compressed-Sensing algorithm (PICCS). The images reconstructed by PICCS outperform the reconstruction results of the conventional Feldkamp-Davis-Kress algorithm (FDK) based method if only a small number of projections are available. However, a drawback of PICCS is that major deviations between prior image data sets and

  12. Development of a versatile algorithm for optimization of radiation therapy

    International Nuclear Information System (INIS)

    Gustafsson, Anders.

    1996-12-01

    A flexible iterative gradient algorithm for radiation therapy optimization has been developed. The algorithm is based on dose calculation using the pencil-beam description of external radiation beams in uniform and heterogeneous patients. The properties of the algorithm are described, including its ability to treat variable bounds and linear constraints, its efficiency in gradient calculation, its convergence properties and termination criteria. 116 refs

  13. Evaluation of multiple image-based modalities for image-guided radiation therapy (IGRT) of prostate carcinoma: A prospective study

    International Nuclear Information System (INIS)

    Mayyas, Essa; Chetty, Indrin J.; Chetvertkov, Mikhail; Wen, Ning; Neicu, Toni; Nurushev, Teamor; Ren Lei; Pradhan, Deepak; Movsas, Benjamin; Elshaikh, Mohamed A.; Lu Mei; Stricker, Hans

    2013-01-01

    Purpose: Setup errors and prostate intrafraction motion are main sources of localization uncertainty in prostate cancer radiation therapy. This study evaluates four different imaging modalities 3D ultrasound (US), kV planar images, cone-beam computed tomography (CBCT), and implanted electromagnetic transponders (Calypso/Varian) to assess inter- and intrafraction localization errors during intensity-modulated radiation therapy based treatment of prostate cancer. Methods: Twenty-seven prostate cancer patients were enrolled in a prospective IRB-approved study and treated to a total dose of 75.6 Gy (1.8 Gy/fraction). Overall, 1100 fractions were evaluated. For each fraction, treatment targets were localized using US, kV planar images, and CBCT in a sequence defined to determine setup offsets relative to the patient skin tattoos, intermodality differences, and residual errors for each patient and patient cohort. Planning margins, following van Herk's formalism, were estimated based on error distributions. Calypso-based localization was not available for the first eight patients, therefore centroid positions of implanted gold-seed markers imaged prior to and immediately following treatment were used as a motion surrogate during treatment. For the remaining 19 patients, Calypso transponders were used to assess prostate intrafraction motion. Results: The means (μ), and standard deviations (SD) of the systematic (Σ) and random errors (σ) of interfraction prostate shifts (relative to initial skin tattoo positioning), as evaluated using CBCT, kV, and US, averaged over all patients and fractions, were: [μ CBCT = (−1.2, 0.2, 1.1) mm, Σ CBCT = (3.0, 1.4, 2.4) mm, σ CBCT = (3.2, 2.2, 2.5) mm], [μ kV = (−2.9, −0.4, 0.5) mm, Σ kV = (3.4, 3.1, 2.6) mm, σ kV = (2.9, 2.0, 2.4) mm], and [μ US = (−3.6, −1.4, 0.0) mm, Σ US = (3.3, 3.5, 2.8) mm, σ US = (4.1, 3.8, 3.6) mm], in the anterior–posterior (A/P), superior–inferior (S/I), and the left–right (L

  14. Evaluation of multiple image-based modalities for image-guided radiation therapy (IGRT) of prostate carcinoma: A prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Mayyas, Essa; Chetty, Indrin J.; Chetvertkov, Mikhail; Wen, Ning; Neicu, Toni; Nurushev, Teamor; Ren Lei; Pradhan, Deepak; Movsas, Benjamin; Elshaikh, Mohamed A. [Department of Radiation Oncology, Henry Ford Health System, 2799 West Grand Boulevard, Detroit, Michigan 48202 (United States); Lu Mei [Department of Public Health Sciences, Henry Ford Health System, 2799 West Grand Boulevard, Detroit Michigan 48202 (United States); Stricker, Hans [Department of Urology, Henry Ford Health System, 2799 West Grand Boulevard, Detroit Michigan 48202 (United States)

    2013-04-15

    Purpose: Setup errors and prostate intrafraction motion are main sources of localization uncertainty in prostate cancer radiation therapy. This study evaluates four different imaging modalities 3D ultrasound (US), kV planar images, cone-beam computed tomography (CBCT), and implanted electromagnetic transponders (Calypso/Varian) to assess inter- and intrafraction localization errors during intensity-modulated radiation therapy based treatment of prostate cancer. Methods: Twenty-seven prostate cancer patients were enrolled in a prospective IRB-approved study and treated to a total dose of 75.6 Gy (1.8 Gy/fraction). Overall, 1100 fractions were evaluated. For each fraction, treatment targets were localized using US, kV planar images, and CBCT in a sequence defined to determine setup offsets relative to the patient skin tattoos, intermodality differences, and residual errors for each patient and patient cohort. Planning margins, following van Herk's formalism, were estimated based on error distributions. Calypso-based localization was not available for the first eight patients, therefore centroid positions of implanted gold-seed markers imaged prior to and immediately following treatment were used as a motion surrogate during treatment. For the remaining 19 patients, Calypso transponders were used to assess prostate intrafraction motion. Results: The means ({mu}), and standard deviations (SD) of the systematic ({Sigma}) and random errors ({sigma}) of interfraction prostate shifts (relative to initial skin tattoo positioning), as evaluated using CBCT, kV, and US, averaged over all patients and fractions, were: [{mu}{sub CBCT}= (-1.2, 0.2, 1.1) mm, {Sigma}{sub CBCT}= (3.0, 1.4, 2.4) mm, {sigma}{sub CBCT}= (3.2, 2.2, 2.5) mm], [{mu}{sub kV}= (-2.9, -0.4, 0.5) mm, {Sigma}{sub kV}= (3.4, 3.1, 2.6) mm, {sigma}{sub kV}= (2.9, 2.0, 2.4) mm], and [{mu}{sub US}= (-3.6, -1.4, 0.0) mm, {Sigma}{sub US}= (3.3, 3.5, 2.8) mm, {sigma}{sub US}= (4.1, 3.8, 3.6) mm], in the anterior

  15. Intensity-Modulated Radiation Therapy (IMRT)

    Science.gov (United States)

    ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: Thank ... Cancer Treatment Head and Neck Cancer Treatment Introduction to Cancer Therapy (Radiation Oncology) ...

  16. Preoperative breast radiation therapy: Indications and perspectives

    DEFF Research Database (Denmark)

    Lightowlers, S V; Boersma, L J; Fourquet, A

    2017-01-01

    Preoperative breast radiation therapy (RT) is not a new concept, but older studies failed to change practice. More recently, there has been interest in revisiting preoperative RT using modern techniques. This current perspective discusses the indications, summarises the published literature...

  17. Modern Radiation Therapy for Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    Specht, Lena; Yahalom, Joachim; Illidge, Tim

    2014-01-01

    on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy...... optimal imaging is available, is explained. A new concept, involved site radiation therapy (ISRT), is introduced as the standard conformal therapy for the scenario, commonly encountered, wherein optimal imaging is not available. There is increasing evidence that RT doses used in the past are higher than...... (ILROG) Steering Committee regarding the modern approach to RT in the treatment of HL, outlining a new concept of ISRT in which reduced treatment volumes are planned for the effective control of involved sites of HL. Nodal and extranodal non-Hodgkin lymphomas (NHL) are covered separately by ILROG...

  18. Pediatric radiation therapy. A Japanese nationwide survey

    International Nuclear Information System (INIS)

    Nemoto, Kenji; Nagata, Yasushi; Hirokawa, Yutaka

    2006-01-01

    A national survey on the current status of pediatric radiation therapy was performed in October 2004. We sent questionnaires to 638 radiotherapy facilities in Japan (except for Kansai area) and 245 responses were analyzed. According to the database of committee of Japanese Society of Therapeutic Radiology and Oncology (JASTRO), the number of pediatric patients who received radiation therapy during 2003 in Japan was 1,101. The most frequent pediatric malignancy was brain tumor, followed by leukemia and lymphoma. The total effort of radiation therapy for children was two to six times larger than that for adult patients. An additional fee seems to be necessary for the highly technical and laborious radiation therapy required for children. (author)

  19. Effect of radiation therapy against intracranial hemangiopericytoma

    International Nuclear Information System (INIS)

    Uemura, Shozaburo; Kuratsu, Jun-ichi; Hamada, Jun-ichiro; Yoshioka, Susumu; Kochi, Masato; Ushio, Yukitaka; Nakahara, Tadashi; Kishida, Katsuaki.

    1992-01-01

    Seven cases of intracranial hemangiopericytoma were studied retrospectively to investigate the efficacy of radiation therapy. Tumor response evaluated by computed tomography and magnetic resonance imaging was obvious after 20-30 Gy irradiation. The total reduction rate was 80-90% and continued as long as 5-7 months after treatment. In five patients receiving radiation therapy before radical removal, the tumors were easily removed without massive hemorrhage. Histological inspection of specimens after irradiation showed a significant disappearance of tumor cells. Pyknosis frequently occurred in endothelial cells, and proliferating vessels with hyalinoid degeneration were also seen. Reticulin fibers between tumor cells were fewer, split, or absent. Preoperative radiation therapy is useful in the treatment of hemangiopericytoma involving considerable surgical risk. Postoperative radiation therapy should be given even if removal is complete. (author)

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

    Science.gov (United States)

    Gravis, Gwenaelle; Faure, Marjorie; Rybikowski, Stanislas; Dermeche, Slimane; Tyran, Marguerite; Calderon, Benoit; Thomassin, Jeanne; Walz, Jochen; Salem, Naji

    2015-11-01

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

  1. Modern radiation therapy for primary cutaneous lymphomas

    DEFF Research Database (Denmark)

    Specht, Lena; Dabaja, Bouthaina; Illidge, Tim

    2015-01-01

    , either as the sole treatment or as part of a multimodality approach. Radiation therapy of primary cutaneous lymphomas requires the use of special techniques that form the focus of these guidelines. The International Lymphoma Radiation Oncology Group has developed these guidelines after multinational...... meetings and analysis of available evidence. The guidelines represent an agreed consensus view of the International Lymphoma Radiation Oncology Group steering committee on the use of radiation therapy in primary cutaneous lymphomas in the modern era.......Primary cutaneous lymphomas are a heterogeneous group of diseases. They often remain localized, and they generally have a more indolent course and a better prognosis than lymphomas in other locations. They are highly radiosensitive, and radiation therapy is an important part of the treatment...

  2. Memory and survival after microbeam radiation therapy

    International Nuclear Information System (INIS)

    Schueltke, Elisabeth; Juurlink, Bernhard H.J.; Ataelmannan, Khalid; Laissue, Jean; Blattmann, Hans; Braeuer-Krisch, Elke; Bravin, Alberto; Minczewska, Joanna; Crosbie, Jeffrey; Taherian, Hadi; Frangou, Evan; Wysokinsky, Tomasz; Chapman, L. Dean; Griebel, Robert; Fourney, Daryl

    2008-01-01

    Background: Disturbances of memory function are frequently observed in patients with malignant brain tumours and as adverse effects after radiotherapy to the brain. Experiments in small animal models of malignant brain tumour using synchrotron-based microbeam radiation therapy (MRT) have shown a promising prolongation of survival times. Materials and methods: Two animal models of malignant brain tumour were used to study survival and memory development after MRT. Thirteen days after implantation of tumour cells, animals were submitted to MRT either with or without adjuvant therapy (buthionine-SR-sulfoximine = BSO or glutamine). We used two orthogonal 1-cm wide arrays of 50 microplanar quasiparallel microbeams of 25 μm width and a center-to-center distance of about 200 μm, created by a multislit collimator, with a skin entrance dose of 350 Gy for each direction. Object recognition tests were performed at day 13 after tumour cell implantation and in monthly intervals up to 1 year after tumour cell implantation. Results: In both animal models, MRT with and without adjuvant therapy significantly increased survival times. BSO had detrimental effects on memory function early after therapy, while administration of glutamine resulted in improved memory

  3. Feasibility of a Mobile Application to Enhance Swallowing Therapy for Patients Undergoing Radiation-Based Treatment for Head and Neck Cancer.

    Science.gov (United States)

    Starmer, Heather M; Abrams, Rina; Webster, Kimberly; Kizner, Jennifer; Beadle, Beth; Holsinger, F Christopher; Quon, Harry; Richmon, Jeremy

    2017-09-30

    Dysphagia following treatment for head and neck cancer is one of the most significant morbidities impacting quality of life. Despite the value of prophylactic exercises to mitigate the impact of radiation on long-term swallowing function, adherence to treatment is limited. The purpose of this investigation was to explore the feasibility of a mobile health application to support patient adherence to swallowing therapy during radiation-based treatment. 36 patients undergoing radiation therapy were provided with the Vibrent™ mobile application as an adjunct to standard swallowing therapy. The application included exercise videos, written instructions, reminders, exercise logging, and educational content. 80% of participants used the app during treatment and logged an average of 102 exercise sessions over the course of treatment. 25% of participants logged at least two exercise sessions per day over the 7-week treatment period, and 53% recorded at least one session per day. Exit interviews regarding the patient experience with the Vibrent™ mobile application were largely positive, but also provided actionable strategies to improve future versions of the application. The Vibrent™ mobile application appears to be a tool that can be feasibly integrated into existing patient care practices and may assist patients in adhering to treatment recommendations and facilitate communication between patients and providers between encounters.

  4. Nursing care update: Internal radiation therapy

    International Nuclear Information System (INIS)

    Lowdermilk, D.L.

    1990-01-01

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

  5. An Atlas-Based Electron Density Mapping Method for Magnetic Resonance Imaging (MRI)-Alone Treatment Planning and Adaptive MRI-Based Prostate Radiation Therapy

    International Nuclear Information System (INIS)

    Dowling, Jason A.; Lambert, Jonathan; Parker, Joel; Salvado, Olivier; Fripp, Jurgen; Capp, Anne; Wratten, Chris; Denham, James W.; Greer, Peter B.

    2012-01-01

    Purpose: Prostate radiation therapy dose planning directly on magnetic resonance imaging (MRI) scans would reduce costs and uncertainties due to multimodality image registration. Adaptive planning using a combined MRI-linear accelerator approach will also require dose calculations to be performed using MRI data. The aim of this work was to develop an atlas-based method to map realistic electron densities to MRI scans for dose calculations and digitally reconstructed radiograph (DRR) generation. Methods and Materials: Whole-pelvis MRI and CT scan data were collected from 39 prostate patients. Scans from 2 patients showed significantly different anatomy from that of the remaining patient population, and these patients were excluded. A whole-pelvis MRI atlas was generated based on the manually delineated MRI scans. In addition, a conjugate electron-density atlas was generated from the coregistered computed tomography (CT)-MRI scans. Pseudo-CT scans for each patient were automatically generated by global and nonrigid registration of the MRI atlas to the patient MRI scan, followed by application of the same transformations to the electron-density atlas. Comparisons were made between organ segmentations by using the Dice similarity coefficient (DSC) and point dose calculations for 26 patients on planning CT and pseudo-CT scans. Results: The agreement between pseudo-CT and planning CT was quantified by differences in the point dose at isocenter and distance to agreement in corresponding voxels. Dose differences were found to be less than 2%. Chi-squared values indicated that the planning CT and pseudo-CT dose distributions were equivalent. No significant differences (p > 0.9) were found between CT and pseudo-CT Hounsfield units for organs of interest. Mean ± standard deviation DSC scores for the atlas-based segmentation of the pelvic bones were 0.79 ± 0.12, 0.70 ± 0.14 for the prostate, 0.64 ± 0.16 for the bladder, and 0.63 ± 0.16 for the rectum. Conclusions: The

  6. Development of an autonomous treatment planning strategy for radiation therapy with effective use of population-based prior data.

    Science.gov (United States)

    Wang, Huan; Dong, Peng; Liu, Hongcheng; Xing, Lei

    2017-02-01

    Current treatment planning remains a costly and labor intensive procedure and requires multiple trial-and-error adjustments of system parameters such as the weighting factors and prescriptions. The purpose of this work is to develop an autonomous treatment planning strategy with effective use of prior knowledge and in a clinically realistic treatment planning platform to facilitate radiation therapy workflow. Our technique consists of three major components: (i) a clinical treatment planning system (TPS); (ii) a formulation of decision-function constructed using an assemble of prior treatment plans; (iii) a plan evaluator or decision-function and an outer-loop optimization independent of the clinical TPS to assess the TPS-generated plan and to drive the search toward a solution optimizing the decision-function. Microsoft (MS) Visual Studio Coded UI is applied to record some common planner-TPS interactions as subroutines for querying and interacting with the TPS. These subroutines are called back in the outer-loop optimization program to navigate the plan selection process through the solution space iteratively. The utility of the approach is demonstrated by using clinical prostate and head-and-neck cases. An autonomous treatment planning technique with effective use of an assemble of prior treatment plans is developed to automatically maneuver the clinical treatment planning process in the platform of a commercial TPS. The process mimics the decision-making process of a human planner and provides a clinically sensible treatment plan automatically, thus reducing/eliminating the tedious manual trial-and-errors of treatment planning. It is found that the prostate and head-and-neck treatment plans generated using the approach compare favorably with that used for the patients' actual treatments. Clinical inverse treatment planning process can be automated effectively with the guidance of an assemble of prior treatment plans. The approach has the potential to

  7. A DICOM-RT based ePR radiation therapy information system for managing brain tumor patients

    Science.gov (United States)

    Liu, Brent J.; Law, Maria; Huang, H. K.; Zee, C. S.; Chan, Lawrence

    2005-04-01

    The need for comprehensive clinical image data and relevant information in image-guided Radiation Therapy (RT) is becoming steadily apparent. Multiple standalone systems utilizing the most technological advancements in imaging, therapeutic radiation, and computerized treatment planning systems acquire key data during the RT treatment course of a patient. One example are patients treated for brain tumors of greater sizes and irregular shapes that utilize state-of-the-art RT technology to deliver pinpoint accurate radiation doses. One such system, the Cyberknife, is a radiation treatment system that utilizes image-guided information to control a multi-jointed, six degrees of freedom, robotic arm to deliver precise and required radiation dose to the tumor site of a cancer patient. The image-guided system is capable of tracking the lesion orientations with respect to the patient"s position throughout the treatment process. This is done by correlating live radiographic images with pre-operative, CT and MR imaging information to determine relative patient and tumor position repeatedly over the course of the treatment. The disparate and complex data generated by the Cyberknife system along with related data is scattered throughout the RT department compromising an efficient clinical workflow since the data crucial for a clinical decision may be time-consuming to retrieve, temporarily missing, or even lost. To address these shortcomings, the ACR-NEMA Standards Committee extended its DICOM (Digital Imaging & Communications in Medicine) Standard from Radiology to RT by ratifying seven DICOM RT objects starting in 1997. However, they are rarely used by the RT community in daily clinical operations. In the past, the research focus of an RT department has primarily been developing new protocols and devices to improve treatment process and outcomes of cancer patients with minimal effort dedicated to integration of imaging and information systems. Our research, tightly

  8. Regression and statistical shape model based substitute CT generation for MRI alone external beam radiation therapy from standard clinical MRI sequences

    Science.gov (United States)

    Ghose, Soumya; Greer, Peter B.; Sun, Jidi; Pichler, Peter; Rivest-Henault, David; Mitra, Jhimli; Richardson, Haylea; Wratten, Chris; Martin, Jarad; Arm, Jameen; Best, Leah; Dowling, Jason A.

    2017-11-01

    In MR only radiation therapy planning, generation of the tissue specific HU map directly from the MRI would eliminate the need of CT image acquisition and may improve radiation therapy planning. The aim of this work is to generate and validate substitute CT (sCT) scans generated from standard T2 weighted MR pelvic scans in prostate radiation therapy dose planning. A Siemens Skyra 3T MRI scanner with laser bridge, flat couch and pelvic coil mounts was used to scan 39 patients scheduled for external beam radiation therapy for localized prostate cancer. For sCT generation a whole pelvis MRI (1.6 mm 3D isotropic T2w SPACE sequence) was acquired. Patients received a routine planning CT scan. Co-registered whole pelvis CT and T2w MRI pairs were used as training images. Advanced tissue specific non-linear regression models to predict HU for the fat, muscle, bladder and air were created from co-registered CT-MRI image pairs. On a test case T2w MRI, the bones and bladder were automatically segmented using a novel statistical shape and appearance model, while other soft tissues were separated using an Expectation-Maximization based clustering model. The CT bone in the training database that was most ‘similar’ to the segmented bone was then transformed with deformable registration to create the sCT component of the test case T2w MRI bone tissue. Predictions for the bone, air and soft tissue from the separate regression models were successively combined to generate a whole pelvis sCT. The change in monitor units between the sCT-based plans relative to the gold standard CT plan for the same IMRT dose plan was found to be 0.3%+/-0.9% (mean  ±  standard deviation) for 39 patients. The 3D Gamma pass rate was 99.8+/-0.00 (2 mm/2%). The novel hybrid model is computationally efficient, generating an sCT in 20 min from standard T2w images for prostate cancer radiation therapy dose planning and DRR generation.

  9. Radiation therapy apparatus having retractable beam stopper

    International Nuclear Information System (INIS)

    Coad, G.L.

    1983-01-01

    This invention relates to a radiation therapy apparatus which utilized a linear translation mechanism for positioning a beam stopper. An apparatus is described wherein the beam stopper is pivotally attached to the therapy machine with an associated drive motor in such a way that the beam stopper retracts linearly

  10. Xerostomia in patients treated for oropharyngeal carcinoma: comparing linear accelerator-based intensity-modulated radiation therapy with helical tomotherapy.

    Science.gov (United States)

    Fortin, Israël; Fortin, Bernard; Lambert, Louise; Clavel, Sébastien; Alizadeh, Moein; Filion, Edith J; Soulières, Denis; Bélair, Manon; Guertin, Louis; Nguyen-Tan, Phuc Felix

    2014-09-01

    In comparison to sliding-window intensity-modulated radiation therapy (sw-IMRT), we hypothesized that helical tomotherapy (HT) would achieve similar locoregional control and, at the same time, decrease the parotid gland dose, thus leading to a xerostomia reduction. The association between radiation techniques, mean parotid dose, and xerostomia incidence, was reviewed in 119 patients with advanced oropharyngeal carcinoma treated with concurrent chemoradiation using sw-IMRT (n = 59) or HT (n = 60). Ipsilateral and contralateral parotid mean doses were significantly lower for patients treated with HT versus sw-IMRT: 24 Gy versus 32 Gy ipsilaterally and 20 Gy versus 25 Gy contralaterally. The incidence of grade ≥2 xerostomia was significantly lower in the HT group than in the sw-IMRT group: 12% versus 78% at 6 months, 3% versus 51% at 12 months, and 0% versus 25% at 24 months. Total parotid mean dose xerostomia at 6, 12, and 24 months. This retrospective series suggests that using HT can better spare the parotid glands while respecting quantitative analysis of normal tissue effects in the clinic (QUANTEC)'s criteria. Copyright © 2013 Wiley Periodicals, Inc.

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

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

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

    2010-01-01

    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.

  13. Evolution of radiation therapy: technology of today

    International Nuclear Information System (INIS)

    Shrivastava, S.K.; Mishra, Shagun

    2013-01-01

    The three well established arms of treatment are surgery, radiation therapy and chemotherapy. The management of cancer is multidisciplinary; Radiation Oncologists along with Surgical Oncologists and Medical Oncologists are responsible for cancer therapeutics. They all work in close collaboration with Pathologists and Radiologists for cancer diagnosis and staging and rely on Oncology Nurses, Physiotherapists, Occupational Therapists, Nutritionists and Social Workers for optimal treatment and rehabilitation of cancer patients. Therefore cancer management is a team work for getting the best results. Radiation therapy is one of the most effective methods of treating cancer

  14. Protective prostheses during radiation therapy

    International Nuclear Information System (INIS)

    Poole, T.S.; Flaxman, N.A.

    1986-01-01

    Current applications and complications in the use of radiotherapy for the treatment of oral malignancy are reviewed. Prostheses are used for decreasing radiation to vital structures not involved with the lesion but located in the field of radiation. With a program of oral hygiene and proper dental care, protective prostheses can help decrease greatly the morbidity seen with existing radiotherapy regimens

  15. Radiation Complications Following Breast Conserving Therapy.

    Science.gov (United States)

    Ikushima; Takegawa; Yasuda; Makimoto; Matsuzaki; Kashihara; Ueno; Sasa; Morimoto; Nishitani

    1998-10-25

    BACKGROUND: Breast conserving therapy is being established as a standard therapeutic procedure for early breast cancer in Japan. However, the indications of radiotherapy and a standardized therapeutic procedure have not been established yet. In this study, complications following radiotherapy were evaluated in patients who had previously undergone breast conserving therapy at Tokushima University Hospital. METHODS From October 1989 to March 1996, 60 women with stage I or II breast cancer underwent radiation therapy after breast conserving surgery, and all patients were followed-up for a median of 27 months. Radiation morbidity scoring of the breast and adjacent organs was performed using the toxity criteria of the Radiation Therapy Oncology Group (RTOG) and European Organization for Research andTreatment of Cancer (EORTC). RESULTS: Only 1 patient developed local recurrence, and no distant metastasisor death was observed. The cause of recurrence in 1 case was considered to be due to extended intraductal component. Although transient dermal reaction was induced by irradiation of the breast, no side effects that may cause cosmetic problems were found. No serious radiation complications were found in the lungs, ribs, heart or other adjacent organs. CONCLUSION: The adverse reactions caused by irradiation does not reduce the merit of combined use of radiation therapy in breast conserving therapy, and therefore, are not the hesitation factor in application of radiotherapy.

  16. Radiation therapy for metastatic spinal tumors

    International Nuclear Information System (INIS)

    Kida, Akio; Fukuda, Haruyuki; Taniguchi, Shuji; Sakai, Kazuaki

    2000-01-01

    The results of radiation therapy for metastatic spinal tumors were evaluated in terms of pain relief, improvement of neurological impairment, and survival. Between 1986 and 1995, 52 symptomatic patients with metastatic spinal tumors treated with radiation therapy were evaluated. The patients all received irradiation of megavoltage energy. Therapeutic efficacy was evaluated in terms of pain relief and improvement of neurological impairment. Pain relief was observed in 29 (61.7%) of 47 patients with pain. Therapy was effective for 17 (70.8%) of 24 patients without neurological impairment, and efficacy was detected in 12 (52.2%) of 23 patients with neurological impairment. Improvement of neurological symptoms was obtained in seven (25.0%) of 28 patients with neurological impairment. Radiation therapy was effective for pain relief in patients with metastatic spinal tumors. In patients with neurological impairment, less pain relief was observed than in those without impairment. Improvement of neurological impairment was restricted, but radiation therapy was thought to be effective in some cases in the early stage of neurological deterioration. Radiation therapy for metastatic spinal tumors contraindicated for surgery was considered effective for improvement of patients' activities of daily living. (author)

  17. Film Dosimetry for Intensity Modulated Radiation Therapy

    International Nuclear Information System (INIS)

    Benites-Rengifo, J.; Martinez-Davalos, A.; Celis, M.; Larraga, J.

    2004-01-01

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

  18. Phase 2 Study of Temozolomide-Based Chemoradiation Therapy for High-Risk Low-Grade Gliomas: Preliminary Results of Radiation Therapy Oncology Group 0424

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Barbara J., E-mail: barbara.fisher@lhsc.on.ca [London Regional Cancer Program, London, Ontario (Canada); Hu, Chen [Radiation Therapy Oncology Group-Statistical Center, Philadelphia, Pennsylvania (United States); Macdonald, David R. [London Regional Cancer Program, London, Ontario (Canada); Lesser, Glenn J. [Wake Forest University Baptist Medical Center, Winston-Salem, North Carolina (United States); Coons, Stephen W. [Barrow Neurological Institute, Phoenix, Arizona (United States); Brachman, David G. [Arizona Oncology Services Foundation, Phoenix, Arizona (United States); Ryu, Samuel [Henry Ford Hospital, Detroit, Michigan (United States); Werner-Wasik, Maria [Thomas Jefferson University Hospital Center, Philadelphia, Pennsylvania (United States); Bahary, Jean-Paul [Centre Hospitalier de l' Université de Montréal-Notre Dame, Montreal, Quebec (Canada); Liu, Junfeng [GCE Solutions, Inc., Bloomington, Illinois (United States); Chakravarti, Arnab [The Ohio State University, The James, Columbus, Ohio (United States); Mehta, Minesh [University of Maryland Medical Systems, Baltimore, Maryland (United States)

    2015-03-01

    Purpose: Radiation Therapy Oncology Group (RTOG) 0424 was a phase 2 study of a high-risk low-grade glioma (LGG) population who were treated with temozolomide (TMZ) and radiation therapy (RT), and outcomes were compared to those of historical controls. This study was designed to detect a 43% increase in median survival time (MST) from 40.5 to 57.9 months and a 20% improvement in 3-year overall survival (OS) rate from 54% to 65% at a 10% significance level (1-sided) and 96% power. Methods and Materials: Patients with LGGs with 3 or more risk factors for recurrence (age ≥40 years, astrocytoma histology, bihemispherical tumor, preoperative tumor diameter of ≥6 cm, or a preoperative neurological function status of >1) were treated with RT (54 Gy in 30 fractions) and concurrent and adjuvant TMZ. Results: From 2005 to 2009, 129 evaluable patients (75 males and 54 females) were accrued. Median age was 49 years; 91% had a Zubrod score of 0 or 1; and 69%, 25%, and 6% of patients had 3, 4, and 5 risk factors, respectively. Patients had median and minimum follow-up examinations of 4.1 years and 3 years, respectively. The 3-year OS rate was 73.1% (95% confidence interval: 65.3%-80.8%), which was significantly improved compared to that of prespecified historical control values (P<.001). Median survival time has not yet been reached. Three-year progression-free survival was 59.2%. Grades 3 and 4 adverse events occurred in 43% and 10% of patients, respectively. One patient died of herpes encephalitis. Conclusions: The 3-year OS rate of 73.1% for RTOG 0424 high-risk LGG patients is higher than that reported for historical controls (P<.001) and the study-hypothesized rate of 65%.

  19. Dosimetric Evaluation and Treatment Outcome of Intensity Modulated Radiation Therapy After Doxorubicin-Based Chemotherapy for Primary Mediastinal Large B-Cell Lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Li-Ming [Department of Radiation Oncology, Cancer Hospital, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing (China); Li, Ye-Xiong, E-mail: yexiong3@yahoo.com.cn [Department of Radiation Oncology, Cancer Hospital, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing (China); Fang, Hui; Jin, Jing; Wang, Wei-Hu; Wang, Shu-Lian; Liu, Yue-Ping; Song, Yong-Wen; Liu, Qing-Feng; Chen, Bo; Qi, Shu-Nan; Ren, Hua; Dai, Jian-Rong [Department of Radiation Oncology, Cancer Hospital, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing (China)

    2013-04-01

    Purpose: The value of intensity-modulated radiation therapy (IMRT) after doxorubicin-based chemotherapy in primary mediastinal large B-cell lymphoma (PMBCL) is unknown. We assessed the dosimetric parameters, treatment outcomes, and toxicity of IMRT in PMBCL. Methods and Materials: Forty-one PMBCL patients underwent mediastinal IMRT after doxorubicin-based chemotherapy. Thirty-eight patients had stage I-II disease, and 3 patients had stage III-IV disease. Most patients presented with bulky mediastinal disease (65.9%) and local invasion (82.9%). The dose-volume histograms of the target volume and critical normal structures were evaluated. Results: The average planning target volume (PTV) mean dose was 39 Gy. Only 0.5% and 1.4% of the PTV received <90% and <95% of the prescribed dose, respectively, indicating excellent target coverage. The median mean lung dose and percentage lung volume receiving 20 Gy (V20) were 16.3 Gy and 30.6%. The 5-year overall survival (OS) and local control (LC) were 95.1% and 89.8%. After chemotherapy, consolidation radiation therapy in patients with complete/partial response resulted in significantly better survival than salvage radiation therapy in patients with stable/progressive disease (3-year OS 100% vs 75%; 3-year LC 96.6% vs 62.5%). No grade 4 or 5 acute or late toxicities occurred. Conclusions: Mediastinal IMRT after doxorubicin-based chemotherapy can be safely and efficiently delivered, and it provides favorable outcomes in PMBCL patients with a large target volume and high-risk features.

  20. Dosimetric Evaluation and Treatment Outcome of Intensity Modulated Radiation Therapy After Doxorubicin-Based Chemotherapy for Primary Mediastinal Large B-Cell Lymphoma

    International Nuclear Information System (INIS)

    Xu, Li-Ming; Li, Ye-Xiong; Fang, Hui; Jin, Jing; Wang, Wei-Hu; Wang, Shu-Lian; Liu, Yue-Ping; Song, Yong-Wen; Liu, Qing-Feng; Chen, Bo; Qi, Shu-Nan; Ren, Hua; Dai, Jian-Rong

    2013-01-01

    Purpose: The value of intensity-modulated radiation therapy (IMRT) after doxorubicin-based chemotherapy in primary mediastinal large B-cell lymphoma (PMBCL) is unknown. We assessed the dosimetric parameters, treatment outcomes, and toxicity of IMRT in PMBCL. Methods and Materials: Forty-one PMBCL patients underwent mediastinal IMRT after doxorubicin-based chemotherapy. Thirty-eight patients had stage I-II disease, and 3 patients had stage III-IV disease. Most patients presented with bulky mediastinal disease (65.9%) and local invasion (82.9%). The dose-volume histograms of the target volume and critical normal structures were evaluated. Results: The average planning target volume (PTV) mean dose was 39 Gy. Only 0.5% and 1.4% of the PTV received <90% and <95% of the prescribed dose, respectively, indicating excellent target coverage. The median mean lung dose and percentage lung volume receiving 20 Gy (V20) were 16.3 Gy and 30.6%. The 5-year overall survival (OS) and local control (LC) were 95.1% and 89.8%. After chemotherapy, consolidation radiation therapy in patients with complete/partial response resulted in significantly better survival than salvage radiation therapy in patients with stable/progressive disease (3-year OS 100% vs 75%; 3-year LC 96.6% vs 62.5%). No grade 4 or 5 acute or late toxicities occurred. Conclusions: Mediastinal IMRT after doxorubicin-based chemotherapy can be safely and efficiently delivered, and it provides favorable outcomes in PMBCL patients with a large target volume and high-risk features

  1. Radiation therapy for cancer patients

    International Nuclear Information System (INIS)

    Mileikowsky, C.

    1987-01-01

    This patent describes an apparatus for irradiating a patient comprising: a source of a radiation beam directed along a radiation axis; means mounting the source for pivotal movement about a first horizontal axis which intersects the source, is stationary with respect to the apparatus, and extends in a direction substantially normal to the radiation axis, whereby the beam is capable of an angular scan in a vertical plane; table means adapted to support a patient to be irradiated; and suspension means mounted the table means for arcuate movement to any positions angularly spaced about the first horizontal axis and for pivoting movement about a second horizontal axis displacement from and substantially parallel to the first horizontal axis. The suspension means maintain the second horizontal axis in substantially intersecting relation to the radiation axis in each of the positions while maintaining a fixed angular position of the table means with respect to the environment

  2. Radiation therapy of benign diseases

    International Nuclear Information System (INIS)

    Order, S.E.; Donaldson, S.

    1990-01-01

    This book reports on the evaluation and treatment of benign disease. The text begins with a chapter concerning standards of practice by an eminent malpractice lawyer, thereby clarifying the medical-legal implications of the radiation treatment of benign disease. The text then lists, in alphabetic order, those benign diseases which have been or are currently treated with radiotherapy for each disease entity. A feature is the survey of current radiation practice in the United States

  3. Scalp Dose Evaluation According Radiation Therapy Technique of Whole Brain Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Joon Yung; Park, Soo Yun; Kim, Jong Sik; Choi, Byeong Gi; Song, Gi Won [Dept. of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2011-09-15

    Opposing portal irradiation with helmet field shape that has been given to a patient with brain metastasis can cause excess dose in patient's scalp, resulting in hair loss. For this reason, this study is to quantitatively analyze scalp dose for effective prevention of hair loss by comparing opposing portal irradiation with scalp-shielding shape and tomotherapy designed to protect patient's scalp with conventional radiation therapy. Scalp dose was measured by using three therapies (HELMET, MLC, TOMO) after five thermo-luminescence dosimeters were positioned along center line of frontal lobe by using RANDO Phantom. Scalp dose and change in dose distribution were compared and analyzed with DVH after radiation therapy plan was made by using Radiation Treatment Planning System (Pinnacle3, Philips Medical System, USA) and 6 MV X-ray (Clinac 6EX, VARIAN, USA). When surface dose of scalp by using thermo-luminescence dosimeters was measured, it was revealed that scalp dose decreased by average 87.44% at each point in MLC technique and that scalp dose decreased by average 88.03% at each point in TOMO compared with HELMET field therapy. In addition, when percentage of volume (V95%, V100%, V105% of prescribed dose) was calculated by using Dose Volume Histogram (DVH) in order to evaluate the existence or nonexistence of hotspot in scalp as to three therapies (HELMET, MLC, TOMO), it was revealed that MLC technique and TOMO plan had good dose coverage and did not have hot spot. Reducing hair loss of a patient who receives whole brain radiotherapy treatment can make a contribution to improve life quality of the patient. It is expected that making good use of opposing portal irradiation with scalp-shielding shape and tomotherapy to protect scalp of a patient based on this study will reduce hair loss of a patient.

  4. Cancer of the larynx: radiation therapy. III

    International Nuclear Information System (INIS)

    Wang, C.C.

    1976-01-01

    Radiation therapy is the treatment of choice for a T1 and T2 tumor with normal cord mobility and/or an exophytic lesion. It not only provides excellent control of the disease, but also preserves a good, useful voice in approximately 90 percent of the irradiated patients. For a T2 lesion with impaired cord mobility and/or moderate ulceration, a trial course of radiotherapy is initially given. If the tumor shows good regression and/or a return of normal cord mobility after a dose of 4000 rads, radiation therapy may be continued to a curative dose level, about 6500 rads. Surgery is reserved for treating residual disease six to eight weeks after radiation therapy or for recurrence. A T3 lesion with complete cord fixation and/or deep ulceration with nodes does not respond favorably to radiation therapy, and a planned combination of irradiation and laryngectomy is advised. Disease that extends beyond the larynx, T4, is rarely curable by radiation therapy alone. If the lesion is still operable, a combined approach of radiation and surgery is preferred; if not, palliative radiation therapy is given. Lymph node metastases from laryngeal carcinoma indicate advanced disease and is managed by preoperative irradiation and radical neck dissection. Under a program of therapeutic individualization, two-thirds to three-quarters of patients with cancer of the larynx can be cured by irradiation with preservation of a good, useful voice. In the remainder, the larynx must be sacrificed to save the patient's life. The ultimate control of laryngeal cancer lies in eradicating the extensive primary lesion and metastatic nodes, a common problem in the management of squamous cell carcinoma elsewhere in the body

  5. Radiation therapy of gastric carcinoma

    International Nuclear Information System (INIS)

    Asakawa, Hiroshi; Yamada, Shogo

    1980-01-01

    A total of 136 cases with gastric cancer was treated with radiation and some anti-cancer drugs. The tumor responded markedly to radiation in 37% of 92 cases, irradiated more than 5000 rad and regressed completely in only 5% of them. Out of them, the permanent cure was achieved in 3% of T2-4 M0 cases. Serious complications, such as hemorrhagic gastritis, massive bleeding, chronic ulcer of the stomach and perforation, were also observed in a few per cent of them. It was suggested that in the treatment of inoperable gastric cancer, the combination treatment of radiation and chemotherapy should be chosen as a valuable therapeutic procedure to get a good palliation. (author)

  6. Risk of hypothyroidism among patients with nasopharyngeal carcinoma treated with radiation therapy: A Population-Based Cohort Study.

    Science.gov (United States)

    Fan, Chao-Yueh; Lin, Chun-Shu; Chao, Hsing-Lung; Huang, Wen-Yen; Su, Yu-Fu; Lin, Kuen-Tze; Tsai, I-Ju; Kao, Chia-Hung

    2017-06-01

    This study aimed to assess the incidence and risk of hypothyroidism among patients with nasopharyngeal carcinoma (NPC) after radiation therapy (RT). We identified 14,893 NPC patients and 16,105 other head and neck cancer (HNC) patients treated with RT without thyroidectomy from the National Health Insurance Research Database in Taiwan between 2000 and 2011. Each NPC patient was randomly frequency-matched with four individuals without NPC by age, sex, and index year. Competing-risk regression models were used to estimate hazard ratios (HRs) of hypothyroidism requiring thyroxin associated with NPC after RT. The risk of developing hypothyroidism was significantly higher in the NPC cohort than in the matched cohort (adjusted HR=14.35, 95% CI=11.85-17.37) and the HNC cohort (adjusted HR=2.06, 95% CI=1.69-2.52). Independent risk factors for hypothyroidism among NPC patients included younger age, female sex, higher urbanization level, autoimmune disease, and receipt of chemotherapy. The risk of hypothyroidism requiring thyroxin was significantly higher in NPC patients after RT than in the general Taiwanese population and HNC patients. Regular clinical and serum thyroid function tests are essential among NPC survivors after RT. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Half-Fan-Based Intensity-Weighted Region-of-Interest Imaging for Low-Dose Cone-Beam CT in Image-Guided Radiation Therapy.

    Science.gov (United States)

    Yoo, Boyeol; Son, Kihong; Pua, Rizza; Kim, Jinsung; Solodov, Alexander; Cho, Seungryong

    2016-10-01

    With the increased use of computed tomography (CT) in clinics, dose reduction is the most important feature people seek when considering new CT techniques or applications. We developed an intensity-weighted region-of-interest (IWROI) imaging method in an exact half-fan geometry to reduce the imaging radiation dose to patients in cone-beam CT (CBCT) for image-guided radiation therapy (IGRT). While dose reduction is highly desirable, preserving the high-quality images of the ROI is also important for target localization in IGRT. An intensity-weighting (IW) filter made of copper was mounted in place of a bowtie filter on the X-ray tube unit of an on-board imager (OBI) system such that the filter can substantially reduce radiation exposure to the outer ROI. In addition to mounting the IW filter, the lead-blade collimation of the OBI was adjusted to produce an exact half-fan scanning geometry for a further reduction of the radiation dose. The chord-based rebinned backprojection-filtration (BPF) algorithm in circular CBCT was implemented for image reconstruction, and a humanoid pelvis phantom was used for the IWROI imaging experiment. The IWROI image of the phantom was successfully reconstructed after beam-quality correction, and it was registered to the reference image within an acceptable level of tolerance. Dosimetric measurements revealed that the dose is reduced by approximately 61% in the inner ROI and by 73% in the outer ROI compared to the conventional bowtie filter-based half-fan scan. The IWROI method substantially reduces the imaging radiation dose and provides reconstructed images with an acceptable level of quality for patient setup and target localization. The proposed half-fan-based IWROI imaging technique can add a valuable option to CBCT in IGRT applications.

  8. Results of radiation therapy in periarthritis humeroscapularis

    International Nuclear Information System (INIS)

    Schultze, J.; Schlichting, G.; Galalae, R.; Kimmig, B.; Koltze, H.

    2004-01-01

    Background: radiation therapy is applied in painful degenerative shoulder diseases. Aim of this work was to evaluate the contribution of radiation therapy to symptomatic improvement in periarthritis humeroscapularis. Methods: ninety-four patients with periarthritis humeroscapularis were treated in two institutions. Mean age was 68 years, sex distribution were 32 men and 62 women. In 58 cases the right side was affected, left in 36 cases. At single doses of 0,75 Gy once a week a total dose of 6 Gy was applied The treatment effect was evaluated by the standardized von Pannewitz-score at the end of the treatment up to 6 months thereafter. Results: the treatment results of all the 94 patients were documentated at the end of therapy. Seventy-one patients were followed at least for further 4 months. Radiogenic side-effects were not noticed. The symptoms of 54 patients (57.4%) were improved or vanished, in 40 cases the symptoms were not significantly affected (42.6%). Four months after therapy 42 of 71 patients were improved (59.2%), 29 unchanged (40.8%). The treatment effect occured typically up to 2 months after therapy, there were no age-related differences. Also in recurrent radiation therapies the symptoms improved, in 80 percent after one preceding therapy, however only in 31.2 percent after multiple prior radiotherapies. (orig.)

  9. Radiation-Induced Second Cancer Risk Estimates From Radionuclide Therapy

    Science.gov (United States)

    Bednarz, Bryan; Besemer, Abigail

    2017-09-01

    The use of radionuclide therapy in the clinical setting is expected to increase significantly over the next decade. There is an important need to understand the radiation-induced second cancer risk associated with these procedures. In this study the radiation-induced cancer risk in five radionuclide therapy patients was investigated. These patients underwent serial SPECT imaging scans following injection as part of a clinical trial testing the efficacy of a 131Iodine-labeled radiopharmaceutical. Using these datasets the committed absorbed doses to multiple sensitive structures were calculated using RAPID, which is a novel Monte Carlo-based 3D dosimetry platform developed for personalized dosimetry. The excess relative risk (ERR) for radiation-induced cancer in these structures was then derived from these dose estimates following the recommendations set forth in the BEIR VII report. The radiation-induced leukemia ERR was highest among all sites considered reaching a maximum value of approximately 4.5. The radiation-induced cancer risk in the kidneys, liver and spleen ranged between 0.3 and 1.3. The lifetime attributable risks (LARs) were also calculated, which ranged from 30 to 1700 cancers per 100,000 persons and were highest for leukemia and the liver for both males and females followed by radiation-induced spleen and kidney cancer. The risks associated with radionuclide therapy are similar to the risk associated with external beam radiation therapy.

  10. Advanced Small Animal Conformal Radiation Therapy Device.

    Science.gov (United States)

    Sharma, Sunil; Narayanasamy, Ganesh; Przybyla, Beata; Webber, Jessica; Boerma, Marjan; Clarkson, Richard; Moros, Eduardo G; Corry, Peter M; Griffin, Robert J

    2017-02-01

    We have developed a small animal conformal radiation therapy device that provides a degree of geometrical/anatomical targeting comparable to what is achievable in a commercial animal irradiator. small animal conformal radiation therapy device is capable of producing precise and accurate conformal delivery of radiation to target as well as for imaging small animals. The small animal conformal radiation therapy device uses an X-ray tube, a robotic animal position system, and a digital imager. The system is in a steel enclosure with adequate lead shielding following National Council on Radiation Protection and Measurements 49 guidelines and verified with Geiger-Mueller survey meter. The X-ray source is calibrated following AAPM TG-61 specifications and mounted at 101.6 cm from the floor, which is a primary barrier. The X-ray tube is mounted on a custom-made "gantry" and has a special collimating assembly system that allows field size between 0.5 mm and 20 cm at isocenter. Three-dimensional imaging can be performed to aid target localization using the same X-ray source at custom settings and an in-house reconstruction software. The small animal conformal radiation therapy device thus provides an excellent integrated system to promote translational research in radiation oncology in an academic laboratory. The purpose of this article is to review shielding and dosimetric measurement and highlight a few successful studies that have been performed to date with our system. In addition, an example of new data from an in vivo rat model of breast cancer is presented in which spatially fractionated radiation alone and in combination with thermal ablation was applied and the therapeutic benefit examined.

  11. Radiation Therapy of Suprasellar Germ Cell Tumors

    International Nuclear Information System (INIS)

    Park, Woo Yoon; Choi, Doo Ho; Choi, Eun Kyung; Kim, Il Han; Ha, Sung Whan; Park, Charn Il

    1988-01-01

    A retrospective study was performed on 15 patients with suprasellar germ cell tumors treated by megavoltage external beam irradiation between Feb. 1979 and Dec. 1985. Follow-up period of survivors was 30 to 91 months. Histologic diagnosis was obtained before radiation therapy in 10 patients (9 germinomas and 1 mixed). Five patients were treated without histologic verification. In 9 patients with biopsy-proven germinomas radiation therapy was delivered to the craniospinal axis in 6, to the whole brain in 3. In 5 patients with mixed germ cell tumor or elevated tumor marker, irradiation was delivered to the craniospinal axis in 2, to the whole brain in 2, and to the primary site only in 1. Total doses ranged from 5,000 to 5,500 cGy to the primary site, 3,000 to 4,400 cGy to the whole brain, and 1,300 to 3,000 cGy to the spine. In these 14, local tumor was controlled and primary or spinal failure was not observed. One patient without elevated tumor marker was treated to the whole brain, The tumor was not controlled and he had spinal recurrence. It is proven that radiation therapy is an effective treatment for suprasellar germ cell tumors. The neuroendocrinologic presentation, tumor marker status, early response to radiation measured on CT seem to be useful means for selecting patients for radiation therapy when tissue diagnosis is not available

  12. TU-H-BRA-08: The Design and Characteristics of a Novel Compact Linac-Based MRI Guided Radiation Therapy (MR-IGRT) System

    Energy Technology Data Exchange (ETDEWEB)

    Mutic, S [Washington University School of Medicine, Saint Louis, MO (United States); Low, D [UCLA, Los Angeles, CA (United States); Chmielewski, T; Fought, G; Hernandez, M; Kawrakow, I; Sharma, A; Shvartsman, S; Dempsey, J [ViewRay, Inc., Oakwood Village, OH (United States)

    2016-06-15

    Purpose: To describe the design and characteristics of a novel linac-based MRI guided radiation therapy system that addresses RF and magnetic field interference and that can be housed in conventional radiotherapy vaults. Methods: The MR-IGRT system will provide simultaneous MR imaging combined with both simple (3D) and complex (IMRT, SBRT, SRS) techniques. The system is a combination of a) double-donut split solenoidal superconducting 0.345T MRI; and b) a 90 cm isocenter ring-gantry mounted 6MV, flattening filter-free linac coupled with a stacked doubly-focused multileaf collimator with 4 mm resolution. A novel RF shielding and absorption technology was developed to isolate the beam generating RF emissions from the MR, while a novel magnetic shielding sleeve system was developed to place the magnetic field-sensitive components in low-magnetic field regions. The system design produces high spatial resolution radiation beams with state-of-the art radiation dose characteristics and simultaneous MR imaging. Results: Prototype testing with a spectrum analyzer has demonstrated complete elimination of linac RF inside the treatment room. The magnetic field inside of the magnetic shielding was well below the specification, allowing the linear accelerator to operate normally. A novel on-gantry shimming system maintained < 25 ppm magnetic field homogeneity over a 45 cm spherical field of view for all gantry angles. Conclusion: The system design demonstrates the feasibility coupling a state-of-the art linac system with a 0.345T MRI, enabling highly conformal radiation therapy with simultaneous MR image guidance. S. Mutic’s employer (Washington University) has grant with ViewRay; D. Low is former ViewRay scientific advisory board member (ended October 2015); T. Chmielewski, G. Fought, M. Hernandez, I. Kawrakow, A. Sharma, S. Shvartsman, J. Dempsey are employees of ViewRay with stock options (Dempsey has leadership role and Dempsey/Kawrakow have stock).

  13. Radiation therapy for resistant sternal hydatid disease

    International Nuclear Information System (INIS)

    Ulger, S.; Barut, H.; Tunc, M.; Aydinkarahaliloglu, E.; Aydin, E.; Karaoglanoglu, N.; Gokcek, A.

    2013-01-01

    Hydatid disease is a zoonotic infectious disease for which there are known treatment procedures and effective antibiotics; however, there are resistant cases that do not respond to medication or surgery. We report a case diagnosed as hydatid disease of the chest wall and treated with radiation therapy (RT) after medical and surgical therapy had failed. In conclusion, RT represents an alternative treatment modality in resistant cases. (orig.)

  14. 21 CFR 892.5300 - Medical neutron radiation therapy system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical neutron radiation therapy system. 892.5300... therapy system. (a) Identification. A medical neutron radiation therapy system is a device intended to generate high-energy neutrons for radiation therapy. This generic type of device may include signal...

  15. Liver cancer and selective internal radiation therapy

    International Nuclear Information System (INIS)

    Sutton, C.

    2002-01-01

    therapies based on its micro-particle technologies, which act as transport vehicles to deliver: 1. ionising radiation (ie. SIR-Spheres, which is used in Selective Internal Radiation Therapy or SIRT); 2. chemotherapy drugs (ie Dox-Spheres); and 3. materials that can generate heat within the cancer (ie. Thermo-Spheres). The original concepts underpinning the core technology commercialised by SIRTeX Medical were initially developed by prominent Australian liver surgeon Dr Bruce Gray and the Cancer Research Institute Inc (CRI) and have been published in the scientific literature. Selective Internal Radiation Therapy using SIR-Spheres has been refined over many years and has been the subject of several clinical trials. Two independent clinical trials are currently underway to evaluate the advantages of using SIR-Spheres in combination with two new anti-cancer drugs to improve the treatment of liver cancer. The first trial will test the efficacy of combining SIR-Spheres with an anti-cancer drug combination that includes irinotecan, a major new drug marketed by Pharmacia for the treatment of advanced bowel cancer. As SIR-Spheres is a novel form of radiotherapy proven to regress bowel cancer that has spread to the liver, it is important to evaluate the benefits of adding increasing doses of irinotecan to SIR-Spheres. Supported by Pharmacia, the trial is being conducted in Australia with a small number of patients, and is expected to be completed by the end of 2002. The second trial will test the use of SIR-Spheres in combination with the drug oxaliplatin - another major anti-cancer drug used for the treatment of advanced bowel cancer. Supported by French-based anti-cancer specialist Sanofi Synthelabo, this trial will be conducted both in Australia and several major cancer centres in Europe. SIRTeX Medical is also currently in the process of researching and developing Dox-Spheres and Thermo-Spheres. Both are based on the same micro-particle technology as SIR-Spheres, but are used to

  16. Definition of treatment geometry in radiation therapy

    International Nuclear Information System (INIS)

    Aaltonen, P.

    1996-01-01

    When accurate systems for quality assurance and treatment optimization are employed, a precise system for fixation and dosimetric and portal verification are as important as a continued and standardized code of practice for dosimetry and patient follow-up, including registration of tumour responses and acute and late normal tissue reactions. To improve the accuracy of existing dose response relations in order to improve future therapy the treatment geometry and dose delivery concepts have to be accurately defined and uniformly employed. A Nordic working group was set up in 1991 (by Nordic Association of Clinica Physics) to standardize the concepts and quantities used during the whole radiotherapy process in the Nordic countries. Now the group is finalizing its report ''Specification of Dose Delivery in Radiation Therapy''. The report emphasizes that the treatment geometry shall be consistent with the geometry used during the diagnostic work up. The patient fixation is of importance early in the diagnostic phase to ensure that the same reference points and patients position will be used both during the diagnostic work up, simulation and treatment execution. Reference Coordinate System of the patient is a concept based on defined anatomic reference points. This Patient Reference System is a local system which has validity for the tissues, organs and volumes defined during radiotherapy. The reference points of the Patient Reference System should in turn be used for beam set-up. The treatment geometry is then defined by using different concepts describing tissues which are mobile in the Patient Reference System, and finally, volumes which are fixed in this coordinate system. A Set-up Margin has to be considered for movements of the volumes defined in the Reference Coordinate System of the Patient in relation to the radiation beam. The Set-up Margin is dependent on the treatment technique and it is needed in the treatment planning procedure to ensure that the prescribed

  17. SU-F-T-508: A Collimator-Based 3-Dimensional Grid Therapy Technique in a Small Animal Radiation Research Platform

    Energy Technology Data Exchange (ETDEWEB)

    Jin, J; Kong, V; Zhang, H [Georgia Regents University, Augusta, GA (Georgia)

    2016-06-15

    Purpose: Three dimensional (3D) Grid Therapy using MLC-based inverse-planning has been proposed to achieve the features of both conformal radiotherapy and spatially fractionated radiotherapy, which may deliver very high dose in a single fraction to portions of a large tumor with relatively low normal tissue dose. However, the technique requires relatively long delivery time. This study aims to develop a collimator-based 3D grid therapy technique. Here we report the development of the technique in a small animal radiation research platform. Methods: Similar as in the MLC-based technique, 9 non-coplanar beams in special channeling directions were used for the 3D grid therapy technique. Two specially designed grid collimators were fabricated, and one of them was selectively used to match the corresponding gantry/couch angles so that the grid opening of all 9 beams are met in the 3D space in the target. A stack of EBT3 films were used as 3D dosimetry to demonstrate the 3D grid-like dose distribution in the target. Three 1-mm beams were delivered to the stack of films in the area outside the target for alignment when all the films were scanned to reconstruct the 3D dosimtric image. Results: 3D film dosimetry showed a lattice-like dose distribution in the 3D target as well as in the axial, sagittal and coronal planes. The dose outside the target also showed a grid like dose distribution, and the average dose gradually decreased with the distance to the target. The peak to valley ratio was approximately 5:1. The delivery time was 7 minutes for 18 Gy peak dose, comparing to 6 minutes to deliver a 18-Gy 3D conformal plan. Conclusion: We have demonstrated the feasibility of the collimator-based 3D grid therapy technique which can significantly reduce delivery time comparing to MLC-based inverse planning technique.

  18. The synergistic effect of nanoparticles in photodynamic therapy and radiation therapy

    International Nuclear Information System (INIS)

    Chen Na; Tu Yu; Zhang Xuguang

    2010-01-01

    This paper describes a novel treatment: based on nanoparticles that combines radiotherapy and photodynamic therapy. With this approach, the application of traditional photodynamic therapies only to surface treatment can be solved, so that the therapeutic effect can be improved; the approach also could guarantee the effectiveness of treatment and reduce radiation doses, so it can effectively control the complications of radiotherapy, This new modality will open a new chapter for cancer therapy. (authors)

  19. Postoperative radiation therapy for adenoid cystic carcinoma

    International Nuclear Information System (INIS)

    Oguchi, Masahiko; Shikama, Naoto; Gomi, Koutarou; Shinoda, Atsunori; Nishikawa, Atsushi; Arakawa, Kazukiyo; Sasaki, Shigeru; Takei, Kazuyoshi; Sone, Syusuke

    2000-01-01

    The authors retrospectively assessed the usefulness of postoperative radiation therapy after local resection of adenoid cystic carcinoma, with emphasis on organ-conserving treatment and the cosmetic results. Between 1985 and 1995, 32 patients underwent local resection followed by postoperative radiation therapy with curative and organ-conserving intent. None of patients received any form of chemotherapy as part of their initial treatment. Radiation therapy was carried out by techniques that were appropriate for the site and extension of each tumor. The 5-year local control, disease-free, and overall survival rates of all patients were 76%, 68%, and 86%, respectively. The 5-year local control rate and disease-free survival rate of patients with microscopically positive margins were 89% and 75%, respectively, and higher than in patients with macroscopically residual disease, but no significant difference in 5-year overall survival rate was observed. The postoperative cosmetic results in 29 patients with head and neck lesions were evaluated. No difference was documented between the cosmetic results postoperatively setting and after postoperative radiotherapy, and no significant differences in cosmetic results were observed according to radiation dose. The combination of local resection with organ-conserving intent and postoperative radiation therapy provided good cosmetic results in patients with T1 or T2 lesions. Postoperative radiation therapy with smaller fractions is useful, because good local control can be achieved in patients with adenoid cystic carcinoma having microscopically positive margins without inducing any late adverse reactions. However, the number of patients was too small and the follow-up period was too short to draw any definite conclusion in regard to fraction size. A much longer follow-up study with a larger number patients will be required to accurately determine the optimal treatment intensity and duration of treatment. (K.H.)

  20. Bullous pemphigoid after radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-02-01

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

  1. Radiation dose received by TAMVEC neutron therapy staff

    International Nuclear Information System (INIS)

    Smathers, J.B.; Graves, R.G.; Sandel, P.S.; Almond, P.R.; Otte, V.A.; Grant, W.H.

    1978-01-01

    Based on over 5 years of experience in fast neutron radiotherapy, the activation radiation source origins and magnitudes are discussed and the staff radiation exposures reviewed. Source magnitudes were determined using ionization chamber survey instruments and staff doses by commercial TLD and film badge service reports. It is concluded that while staff doses exceed those obtained in conventional therapy, the levels received are well within published guidelines for occupational exposure. (author)

  2. PET/CT in Radiation Therapy Planning

    DEFF Research Database (Denmark)

    Specht, Lena; Berthelsen, Anne Kiil

    2018-01-01

    Radiation therapy (RT) is an important component of the management of lymphoma patients. Most lymphomas are metabolically active and accumulate 18F-fluorodeoxyglucose (FDG). Positron emission tomography with computer tomography (PET/CT) imaging using FDG is used routinely in staging and treatment...

  3. Electron beams in radiation therapy

    International Nuclear Information System (INIS)

    Bruinvis, I.A.D.

    1987-01-01

    Clinical electron beams in interaction with beam flattening and collimating devices are studied, in order to obtain the means for adequate electron therapy. A treatment planning method for arbitrary field shapes is developed that takes the properties of the collimated electron beams into account. An electron multiple-scattering model is extended to incorporate a model for the loss of electrons with depth, in order to improve electron beam dose planning. A study of ionisation measurements in two different phantom materials yields correction factors for electron beam dosimetry. (Auth.)

  4. Radiation therapy for esophageal carcinoma

    International Nuclear Information System (INIS)

    Chatani, Masashi; Matayoshi, Yoshinobu; Masaki, Norie

    1992-01-01

    From 1977 through 1989, 149 patients with esophageal carcinoma were treated with external irradiation (EI) with or without high-dose rate intraluminal irradiation (HDRII) using remote afterloading system. Concerning complete response group EI alone showed higher local control rate than EI + HDRII, especially in ulcerative type. Another problem is the EI field. Fourteen of 22 patients who were salvaged by surgery due to local recurrence after EI showed marginal or out-field metastasis of the lymph node. These preliminary results suggest that HDRII is not effective for the local control of the ulcerative lesion as a boost therapy, EI should be given for the entire regional lymph nodes. (author)

  5. Cherenkov excited phosphorescence-based pO2 estimation during multi-beam radiation therapy: phantom and simulation studies.

    Science.gov (United States)

    Holt, Robert W; Zhang, Rongxiao; Esipova, Tatiana V; Vinogradov, Sergei A; Glaser, Adam K; Gladstone, David J; Pogue, Brian W

    2014-09-21

    Megavoltage radiation beams used in External Beam Radiotherapy (EBRT) generate Cherenkov light emission in tissues and equivalent phantoms. This optical emission was utilized to excite an oxygen-sensitive phosphorescent probe, PtG4, which has been developed specifically for NIR lifetime-based sensing of the partial pressure of oxygen (pO2). Phosphorescence emission, at different time points with respect to the excitation pulse, was acquired by an intensifier-gated CCD camera synchronized with radiation pulses delivered by a medical linear accelerator. The pO2 distribution was tomographically recovered in a tissue-equivalent phantom during EBRT with multiple beams targeted from different angles at a tumor-like anomaly. The reconstructions were tested in two different phantoms that have fully oxygenated background, to compare a fully oxygenated and a fully deoxygenated inclusion. To simulate a realistic situation of EBRT, where the size and location of the tumor is well known, spatial information of a prescribed region was utilized in the recovery estimation. The phantom results show that region-averaged pO2 values were recovered successfully, differentiating aerated and deoxygenated inclusions. Finally, a simulation study was performed showing that pO2 in human brain tumors can be measured to within 15 mmHg for edge depths less than 10-20 mm using the Cherenkov Excited Phosphorescence Oxygen imaging (CEPhOx) method and PtG4 as a probe. This technique could allow non-invasive monitoring of pO2 in tumors during the normal process of EBRT, where beams are generally delivered from multiple angles or arcs during each treatment fraction.

  6. Selective internal radiation therapy for liver tumours.

    Science.gov (United States)

    Sundram, Francis X; Buscombe, John R

    2017-10-01

    Primary and secondary liver malignancies are common and associated with a poor prognosis. Surgical resection is the treatment of choice; however, many patients have unresectable disease. In these cases, several liver directed therapies are available, including selective internal radiation therapy (SIRT). SIRT is a multidisciplinary treatment involving nuclear medicine, interventional radiology and oncology. High doses of localised internal radiation are selectively delivered to liver tumour tissues, with relative sparing of adjacent normal liver parenchyma. Side effects are minimal and radiation protection measures following treatment are straightforward. In patients who have progressed following chemotherapy, clinical trials demonstrate prolonged liver progression-free survival. SIRT is offered at 10 centres in England via the NHS England Commissioning through Evaluation programme and is approved by the National Institute for Health and Care Excellence for certain liver malignancies. SIRT holds unique promise for personalised treatment of liver tumours. © Royal College of Physicians 2017. All rights reserved.

  7. Drug delivery system and radiation therapy

    International Nuclear Information System (INIS)

    Shibata, Tokushi

    2005-01-01

    This paper describes the review of radiation therapy, neutron capture therapy (NCT) and drug delivery system for the latter. In cancer radiation therapy, there are problems of body movement like breathing, needless irradiation of normal tissues, difficulty to decide the correct irradiation position and tumor morphology. NCT has advantages to overcome these, and since boron has a big cross section for thermal neutron, NPT uses the reaction 10 B(n, α) 7 Li in the target cancer which previously incorporated the boron-containing drug. During the period 1966-1996, 246 patients were treated with this in Japan and the treatment has been continued thereafter. The tasks for NCT are developments of drug delivery system efficient to deliver the drug into the tumor and of convenient neutron source like the accelerator. (S.I.)

  8. Radiation therapy of Graves' ophthalmopathy

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Toshiki; Koga, Sukehiko; Anno, Hirofumi; Komai, Satoshi (Fujita-Gakuen Health Univ., Toyoake, Aichi (Japan))

    1992-01-01

    During the decade from 1978 to 1987, 20 patients with Graves' ophthalmopathy were treated with irradiation of 2000 cGy to the orbital tissue. We examined the effects of the therapy on 17 such patients. Exophthalmos tended to decrease. When the degree of deviation of the exophthalmic eye was small, the effect of therapy tended to be better than when it was large. Two cases that showed an increase in retrobulbar fatty tissue without thickening of the extraocular muscles did not respond as well as those that had thickening of the extraocular muscles. Diplopia tended to improve both subjectively and objectively. Ocular movement improved in 11 of the 17 patients. There were no serious radiation injuries after the radiation therapy, except for some transient swelling of the eyelid. (author).

  9. Database for radiation therapy images

    International Nuclear Information System (INIS)

    Shalev, S.; Cosby, S.; Leszczynski, K.; Chu, T.

    1989-01-01

    The authors have developed a database for images acquired during simulation and verification of radiation treatments. Simulation images originate as planning films that are digitized with a video camera, or through direct digitization of fluoroscopic images. Verification images may also be digitized from portal films or acquired with an on-line portal imaging system. Images are classified by the patient, the fraction, the field direction, static or dynamic (movie) sequences, and the type of processing applied. Additional parameters indicate whether the source is a simulation or treatment, whether images are digitized film or real-time acquisitions, and whether treatment is portal or double exposure for beam localization. Examples are presented for images acquired, processed, stored, and displayed with on-line portal imaging system (OPIUM) and digital simulation system (FLIP)

  10. Electron wedges for radiation therapy

    International Nuclear Information System (INIS)

    Lief, Eugene P.; Lo, Y.-C.; Humm, John L.

    1998-01-01

    Purpose: Brain tumors can be advantageously treated with electron over photon radiation, by exploiting the rapid fall-off in dose with depth. This advantage could be further enhanced by utilizing multiple electron beams. However, in some beam configurations, wedged dose profiles would be necessary for the dose uniformity. Unlike photons, shaped pieces of material placed in electron beam severely degrade the energy, give additional scattering and, therefore, are suboptimal. The purpose of this study was to create wedged electron fields, using intensity modulation. The combination of electron wedges enables a more uniform coverage of brain tumors with a reduced dose to normal tissue. Methods and Materials: Intensity modulation was performed for 10 to 50 MeV electrons using a narrow scanning elementary beam of a racetrack Microtron accelerator, delivering radiation pulses with coordinates and intensities prescribed by a custom scan matrix. Dispensing more pulses (or longer pulses) within the field to increase the local dose, one can sharpen the penumbra at depth and generate wedged dose distributions of arbitrary angle as well as many other desired profiles. We modulated the electron beams, measured dose distributions using film in an anthropomorphic phantom, and compared the results with conventional techniques. Results: Intensity modulation of electron beams decreases the 50-90% penumbra at depth by 40% and increases the flatness by 80%. Wedged profiles at depth can be created for any angle up to about 70 deg. , depending on the beam energy. Multiple modulated electron beams give smaller 20-70% but larger 70-100% isodose regions than photon beams. Conclusions: Electron beams can improve dose distributions in brain compared to the same number of photon beams, reducing the 20-70% isodoses region in normal tissue by 30%. Intensity modulation significantly improves the dose distribution from combined electron beams providing a sharper penumbra, better conformity, and

  11. Enhanced radiation therapy with internalized polyelectrolyte modified nanoparticles

    Science.gov (United States)

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

    2014-08-01

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

  12. Determinants of job satisfaction among radiation therapy faculty.

    Science.gov (United States)

    Swafford, Larry G; Legg, Jeffrey S

    2009-01-01

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

  13. Guidelines for safe practice of stereotactic body (ablative) radiation therapy

    International Nuclear Information System (INIS)

    Foote, Matthew; Barry, Tamara; Bailey, Michael; Smith, Leigh; Seeley, Anna; Siva, Shankar; Hegi-Johnson, Fiona; Booth, Jeremy; Ball, David; Thwaites, David

    2015-01-01

    The uptake of stereotactic ablative body radiation therapy (SABR) / stereotactic body radiation therapy (SBRT) worldwide has been rapid. The Australian and New Zealand Faculty of Radiation Oncology (FRO) assembled an expert panel of radiation oncologists, radiation oncology medical physicists and radiation therapists to establish guidelines for safe practice of SABR. Draft guidelines were reviewed by a number of international experts in the field and then distributed through the membership of the FRO. Members of the Australian Institute of Radiography and the Australasian College of Physical Scientists and Engineers in Medicine were also asked to comment on the draft. Evidence-based recommendations (where applicable) address aspects of departmental staffing, procedures and equipment, quality assurance measures, as well as organisational considerations for delivery of SABR treatments. Central to the guidelines is a set of key recommendations for departments undertaking SABR. These guidelines were developed collaboratively to provide an educational guide and reference for radiation therapy service providers to ensure appropriate care of patients receiving SABR.

  14. Utilization of Radiation Therapy in Norway After the Implementation of The National Cancer Plan—A National, Population-Based Study

    International Nuclear Information System (INIS)

    Åsli, Linn M.; Kvaløy, Stein O.; Jetne, Vidar; Myklebust, Tor Å.; Levernes, Sverre G.; Tveit, Kjell M.; Green, Tor O.; Johannesen, Tom B.

    2014-01-01

    Purpose: To estimate actual utilization rates of radiation therapy (RT) in Norway, describe time trends (1997-2010), and compare these estimates with corresponding optimal RT rates. Methods and Materials: Data from the population-based Cancer Registry of Norway was used to identify all patients diagnosed with cancer and/or treated by RT for cancer in 1997-2010. Radiation therapy utilization rates (RURs) were calculated as (1) the proportion of incident cancer cases who received RT at least once within 1 year of diagnosis (RUR 1Y ); and (2) the proportion who received RT within 5 years of diagnosis (RUR 5Y ). The number of RT treatment courses per incident cancer case (TCI) was also calculated for all cancer sites combined. The actual RURs were compared with corresponding Australian and Canadian epidemiologic- and evidence-based model estimates and criterion-based benchmark estimates of optimal RURs. The TCIs were compared with TCI estimates from the 1997 Norwegian/National Cancer Plan (NCP). Joinpoint regression was used to identify changes in trends and to estimate annual percentage change (APC) in actual RUR 1Y and actual TCI. Results: The actual RUR 5Y (all sites) increased significantly to 29% in 2005 but still differed markedly from the Australian epidemiologic- and evidence-based model estimate of 48%. With the exception of RUR 5Y for breast cancer and RUR 1Y for lung cancers, all actual RURs were markedly lower than optimal RUR estimates. The actual TCI increased significantly during the study period, reaching 42.5% in 2010, but was still lower than the 54% recommended in the NCP. The trend for RUR 1Y (all sites) and TCI changed significantly, with the annual percentage change being largest during the first part of the study period. Conclusions: Utilization rates of RT in Norway increased after the NCP was implemented and RT capacity was increased, but they still seem to be lower than optimal levels

  15. Time-Resolved Intrafraction Target Translations and Rotations During Stereotactic Liver Radiation Therapy: Implications for Marker-based Localization Accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Bertholet, Jenny, E-mail: jennbe@rm.dk [Department of Oncology, Aarhus University Hospital, Aarhus C (Denmark); Worm, Esben S. [Department of Medical Physics, Aarhus University Hospital, Aarhus C (Denmark); Fledelius, Walther; Høyer, Morten; Poulsen, Per R. [Department of Oncology, Aarhus University Hospital, Aarhus C (Denmark)

    2016-06-01

    Purpose: Image guided liver stereotactic body radiation therapy (SBRT) often relies on implanted fiducial markers. The target localization accuracy decreases with increased marker-target distance. This may occur partly because of liver rotations. The aim of this study was to examine time-resolved translations and rotations of liver marker constellations and investigate if time-resolved intrafraction rotational corrections can improve localization accuracy in liver SBRT. Methods and Materials: Twenty-nine patients with 3 implanted markers received SBRT in 3 to 6 fractions. The time-resolved trajectory of each marker was estimated from the projections of 1 to 3 daily cone beam computed tomography scans and used to calculate the translation and rotation of the marker constellation. In all cone beam computed tomography projections, the time-resolved position of each marker was predicted from the position of another surrogate marker by assuming that the marker underwent either (1) the same translation as the surrogate marker; or (2) the same translation as the surrogate marker corrected by the rotation of the marker constellation. The localization accuracy was quantified as the root-mean-square error (RMSE) between the estimated and the actual marker position. For comparison, the RMSE was also calculated when the marker's position was estimated as its mean position for all the projections. Results: The mean translational and rotational range (2nd-98th percentile) was 2.0 mm/3.9° (right-left), 9.2 mm/2.9° (superior-inferior), 4.0 mm/4.0° (anterior-posterior), and 10.5 mm (3-dimensional). Rotational corrections decreased the mean 3-dimensional RMSE from 0.86 mm to 0.54 mm (P<.001) and halved the RMSE increase per millimeter increase in marker distance. Conclusions: Intrafraction rotations during liver SBRT reduce the accuracy of marker-guided target localization. Rotational correction can improve the localization accuracy with a factor of approximately 2

  16. Spectroscopic properties and radiation damage investigation of a diamond based Schottky diode for ion-beam therapy microdosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Verona, C.; Marinelli, Marco; Verona-Rinati, G. [INFN - Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata,” Roma (Italy); Magrin, G.; Solevi, P.; Mayer, R. [EBG MedAustron Marie Curie-St. 5, 2700 Wiener Neustadt (Austria); Grilj, V.; Jakšić, M. [Ruder Boškovic Institute, Bijenicka cesta 54, P.O. Box 180, 10002 Zagreb (Croatia)

    2015-11-14

    In this work, a detailed analysis of the properties of a novel microdosimeter based on a synthetic single crystal diamond is reported. Focused ion microbeams were used to investigate the device spectropscopic properties as well as the induced radiation damage effects. A diamond based Schottky diode was fabricated by chemical vapor deposition with a very thin detecting region, about 400 nm thick (approximately 1.4 μm water equivalent thickness), corresponding to the typical size in microdosimetric measurements. A 200 × 200 μm{sup 2} square metallic contact was patterned on the diamond surface by standard photolithography to define the sensitive area. Experimental measurements were carried out at the Ruder Boškovic′ Institute microbeam facility using 4 MeV carbon and 5 MeV silicon ions. Ion beam induced charge maps were employed to characterize the microdosimeter response in terms of its charge collection properties. A stable response with no evidence of polarization or memory effects was observed up to the maximum investigated ion beam flux of about 1.7 × 10{sup 9} ions·cm{sup −2}·s{sup −1}. A homogeneity of the response about 6% was found over the sensitive region with a well-defined confinement of the response within the active area. Tests of the radiation damage effect were performed by selectively irradiating small areas of the device with different ion fluences, up to about 10{sup 12} ions/cm{sup 2}. An exponential decrease of the charge collection efficiency was observed with a characteristic decay constant of about 4.8 MGy and 1 MGy for C and Si ions, respectively. The experimental data were analyzed by means of GEANT4 Monte Carlo simulations. A direct correlation between the diamond damaging effect and the Non Ionizing Energy Loss (NIEL) fraction was found. In particular, an exponential decay of the charge collection efficiency with an exponential decay as a function of NIEL is observed, with a characteristic constant of about

  17. Three-dimensional personalized dosimetry for 188Re liver selective internal radiation therapy based on quantitative post-treatment SPECT studies

    Science.gov (United States)

    Shcherbinin, S.; Grimes, J.; Bator, A.; Cwikla, J. B.; Celler, A.

    2014-01-01

    We demonstrate that accurate patient-specific distributions of microspheres labeled with 188Re and resulting absorbed doses can be obtained from single-photon emission computed tomography (SPECT) studies performed after 188Re selective internal radiation therapy when accurate correction methods are employed in image reconstruction. Our quantitative image reconstruction algorithm includes corrections for attenuation, resolution degradations and scatter as well as a window-based compensation for contamination. The procedure has been validated using four phantom experiments containing an 18 ml cylindrical source (82-93 MBq of 188Re activity) simulating a liver tumor. In addition, we applied our approach to post-therapy SPECT studies of ten patients with progressive primary or metastatic liver carcinomas. Our quantitative algorithm accurately (within 9%) recovered 188Re activity from four phantom experiments. In addition, for two patients that received three scans, deviations remained consistent between the measured and the reconstructed activities that were determined from studies with differing severity of the dead-time effect. The analysis of absorbed doses for patient studies allowed us to hypothesize that D90 (the minimum dose received by 90% of the tumor volume) may be a reliable metric relating therapy outcomes to the calculated doses. Among several considered metrics, only D90 showed statistically significant correlation with the overall survival.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  20. Pulsed laser radiation therapy of skin tumors

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  1. Impact of Using Audit Data to Improve the Evidence-Based Use of Single-Fraction Radiation Therapy for Bone Metastases in British Columbia

    International Nuclear Information System (INIS)

    Olson, Robert A.; Tiwana, Manpreet; Barnes, Mark; Cai, Eric; McGahan, Colleen; Roden, Kelsey; Yurkowski, Emily; Gentles, Quinn; French, John; Halperin, Ross; Olivotto, Ivo A.

    2016-01-01

    Purpose: To assess the impact of a population-based intervention to increase the consistency and use of single-fraction radiation therapy (SFRT) for bone metastases. Methods and Materials: In 2012, an audit of radiation therapy prescriptions for bone metastases in British Columbia identified significant interphysician and -center (26%-73%) variation in the use of SFRT. Anonymous physician-level and identifiable regional cancer center SFRT use data were presented to all radiation oncologists, together with published guidelines, meta-analyses, and recommendations from practice leaders. The use of SFRT for bone metastases from 2007 through 2011 was compared with use of SFRT in 2013, to assess the impact of the audit and educational intervention. Multilevel logistic regression was used to assess the relationship between the usage of SFRT and the timing of the radiation while controlling for potentially confounding variables. Physician and center were included as group effects to account for the clustered structure of the data. Results: A total of 16,898 courses of RT were delivered from 2007 through 2011, and 3200 courses were delivered in 2013. The rates of SFRT use in 2007, 2008, 2009, 2010, 2011, and 2013 were 50.5%, 50.9%, 48.3%, 48.5%, 48.0%, and 59.7%, respectively (P<.001). Use of SFRT increased in each of 5 regional centers: A: 26% to 32%; B: 36% to 56%; C: 39% to 57%; D: 49% to 56%; and E: 73% to 85.0%. Use of SFRT was more consistent; 3 of 5 centers used SFRT for 56% to 57% of bone metastases RT courses. The regression analysis showed strong evidence that the usage of SFRT increased after the 2012 intervention (odds ratio 2.27, 95% confidence interval 2.06-2.50, P<.0001). Conclusion: Assessed on a population basis, an audit-based intervention increased utilization of SFRT for bone metastases. The intervention reversed a trend to decreasing SFRT use, reduced costs, and improved patient convenience. This suggests that dissemination of programmatic quality

  2. COMPARISON OF HYPOFRACTIONATED RADIATION THERAPY VERSUS CONVENTIONAL RADIATION THERAPY IN POST MASTECTOMY BREAST CANCER

    Directory of Open Access Journals (Sweden)

    Abhilash

    2016-03-01

    Full Text Available INTRODUCTION Breast cancer is the most common cancer in women worldwide and a leading cause of cancer death in females and accounts for 1.8 million new cases and approximately 0.5 million deaths annually. Patients who present with locally advanced breast cancer (LABC require multidisciplinary team approach that incorporates diagnostic imaging, surgery, chemotherapy and histopathological assessment, including molecular-based studies, radiation, and, if indicated, biologic and hormonal therapies. Hypofractionated radiation therapy following mastectomy has been used in many institutions for several decades and have demonstrated equivalent local control, cosmetic and normal tissues between 50 Gy in 25 fractions and various hypofractionated radiotherapy prescriptions employing 13-16 fractions. Evidence suggests that hypofractionated radiotherapy may also be safe and effective for regional nodal disease. AIMS AND OBJECTIVES To compare the local control and side effects of hypofractionated radiation therapy with conventional radiation therapy in post mastectomy carcinoma breast with stage II and III and to compare the tolerability and compliance of both schedules. MATERIALS AND METHODS The study was conducted on 60 histopathologically proven patients of carcinoma of breast, treated surgically with modified radical mastectomy. Group I patients were given external radiation to chest flap and drainage areas, a dose of 39 Gy/13 fractions/3.1 weeks, a daily dose 3 Gy for 13 fractions in 4 days a week schedule and Group II patients were given external radiation to chest flap and drainage areas, a dose of 50 Gy/25 fractions/5 weeks, to receive a daily dose 2 Gy for 25 fractions in a 5 days a week schedule. RESULTS The median age at presentation in Group I and II was 48 and 50 years respectively. Locoregional control after completion of radiotherapy in Group I vs. Group II was 26/30 (86.7% vs. 27/30 (90% respectively. Acute reactions and their grades in Group

  3. Magnetic Resonance Imaging-Based Target Volume Delineation in Radiation Therapy Treatment Planning for Brain Tumors Using Localized Region-Based Active Contour

    International Nuclear Information System (INIS)

    Aslian, Hossein; Sadeghi, Mahdi; Mahdavi, Seied Rabie; Babapour Mofrad, Farshid; Astarakee, Mahdi; Khaledi, Navid; Fadavi, Pedram

    2013-01-01

    Purpose: To evaluate the clinical application of a robust semiautomatic image segmentation method to determine the brain target volumes in radiation therapy treatment planning. Methods and Materials: A local robust region-based algorithm was used on MRI brain images to study the clinical target volume (CTV) of several patients. First, 3 oncologists delineated CTVs of 10 patients manually, and the process time for each patient was calculated. The averages of the oncologists’ contours were evaluated and considered as reference contours. Then, to determine the CTV through the semiautomatic method, a fourth oncologist who was blind to all manual contours selected 4-8 points around the edema and defined the initial contour. The time to obtain the final contour was calculated again for each patient. Manual and semiautomatic segmentation were compared using 3 different metric criteria: Dice coefficient, Hausdorff distance, and mean absolute distance. A comparison also was performed between volumes obtained from semiautomatic and manual methods. Results: Manual delineation processing time of tumors for each patient was dependent on its size and complexity and had a mean (±SD) of 12.33 ± 2.47 minutes, whereas it was 3.254 ± 1.7507 minutes for the semiautomatic method. Means of Dice coefficient, Hausdorff distance, and mean absolute distance between manual contours were 0.84 ± 0.02, 2.05 ± 0.66 cm, and 0.78 ± 0.15 cm, and they were 0.82 ± 0.03, 1.91 ± 0.65 cm, and 0.7 ± 0.22 cm between manual and semiautomatic contours, respectively. Moreover, the mean volume ratio (=semiautomatic/manual) calculated for all samples was 0.87. Conclusions: Given the deformability of this method, the results showed reasonable accuracy and similarity to the results of manual contouring by the oncologists. This study shows that the localized region-based algorithms can have great ability in determining the CTV and can be appropriate alternatives for manual approaches in brain cancer

  4. SU-F-J-32: Do We Need KV Imaging During CBCT Based Patient Set-Up for Lung Radiation Therapy?

    Energy Technology Data Exchange (ETDEWEB)

    Gopal, A; Zhou, J; Prado, K; D’souza, W; Yi, B [University of Maryland School of Medicine, Baltimore, MD (United States)

    2016-06-15

    Purpose: To evaluate the role of 2D kilovoltage (kV) imaging to complement cone beam CT (CBCT) imaging in a shift threshold based image guided radiation therapy (IGRT) strategy for conventional lung radiotherapy. Methods: A retrospective study was conducted by analyzing IGRT couch shift trends for 15 patients that received lung radiation therapy to evaluate the benefit of performing orthogonal kV imaging prior to CBCT imaging. Herein, a shift threshold based IGRT protocol was applied, which would mandate additional CBCT verification if the applied patient shifts exceeded 3 mm to avoid intraobserver variability in CBCT registration and to confirm table shifts. For each patient, two IGRT strategies: kV + CBCT and CBCT alone, were compared and the recorded patient shifts were categorized into whether additional CBCT acquisition would have been mandated or not. The effectiveness of either strategy was gauged by the likelihood of needing additional CBCT imaging for accurate patient set-up. Results: The use of CBCT alone was 6 times more likely to require an additional CBCT than KV+CBCT, for a 3 mm shift threshold (88% vs 14%). The likelihood of additional CBCT verification generally increased with lower shift thresholds, and was significantly lower when kV+CBCT was used (7% with 5 mm shift threshold, 36% with 2 mm threshold), than with CBCT alone (61% with 5 mm shift threshold, 97% with 2 mm threshold). With CBCT alone, treatment time increased by 2.2 min and dose increased by 1.9 cGy per fraction on average due to additional CBCT with a 3mm shift threshold. Conclusion: The benefit of kV imaging to screen for gross misalignments led to more accurate CBCT based patient localization compared with using CBCT alone. The subsequently reduced need for additional CBCT verification will minimize treatment time and result in less overall patient imaging dose.

  5. External beam radiation therapy for recurrent sigmoid colorectal cancer. Retrospective analysis by group comparison between the radiation therapy alone and the radiation therapy combined with other therapies

    International Nuclear Information System (INIS)

    Churei, Hisahiko; Takeshita, Tsuyoshi; Hiraki, Yoshiyuki; Baba, Yasutaka; Hokotate, Hirohumi; Nakajo, Masayuki; Ohkubo, Kouichi; Miyaji, Noriaki

    1999-01-01

    The purpose of this study is to evaluate retrospectively clinical efficacy of curativeintent external beam radiation therapy for recurrent sigmoid colorectal cancer. As the radiation therapy of higher dose level combined with other therapies might improve pain control, tumor response, and prognosis, the total dose over 60 Gy was delivered except cases that were received surgery for the recurrent tumor. The study population consisted of 25 patients received the radiation therapy alone (RTA) and 24 patients received the radiation therapy combined with other one or two treatment modalities (RTC), which included surgery (tumor resection) in 15 cases, chemotherapy (low dose daily CDDP) in 13 cases, and hyperthermia in 6 cases. They received the radiation therapy from January, 1989 to June, 1996. Data on pain relief and tumor response were compared between the groups of RTA and RTC. The effect on pain relief was not different between the two groups. Tumor response appeared to be high in the patients combined with chemotherapy, but the difference was not statistically significant between the groups. There were no differences in the prognosis by the recurrent tumor size, the pain relief, and the tumor response. There was a statistically significant difference in the prognosis between the groups with and without extrapelvic distant metastases. A more effective treatment modality combined with the external radiation therapy is necessary to improve the clinical efficacy for the recurrent sigmoid colorectal cancer. (author)

  6. Polymer gel dosimetry system for radiation therapy

    International Nuclear Information System (INIS)

    Maryanski, M.J.; Schulz, R.J.; Gignac, C.; Eastman, P.; Gore, J.C.

    1995-01-01

    Purpose/Objective: Recently developed treatment modalities such as stereotactic and conformal radiation therapy produce complex dose distributions which are difficult or impractical to measure with conventional dosimetry instrumentation. Three-dimensional treatment planning systems which purport to calculate these complex dose distributions should be compared to experimental results before being routinely applied to clinical problems. There is a need for a new class of tissue-equivalent dosimeters capable of providing accurate, high resolution, time-integrated and three dimensional dose distributions. The recently developed BANG polymer gel dosimetry system (MGS Research, Inc., Guilford, CT) is ideally suited for the task described above. Physico-chemical principles of the polymer gel dosimetry are presented, together with examples of its application to radiation therapy. Data analysis and display program, written for Macintosh computer, is demonstrated. Materials and Methods: Radiation-induced polymerization of acrylic monomers, which are dispersed in tissue-equivalent gelatin, has been shown to be dependent on the dose, but independent of the dose rate or photon energy. Therefore, the spatial distribution of polymer in the gel is precisely representative of the dose distribution. As the polymeric microparticles reduce the water proton NMR relaxation times in the gel, the dose distribution can be measured with high resolution and accuracy using magnetic resonance imaging. Also, as these microparticles cannot diffuse through the gelatin matrix, their distribution is permanent. An improved formulation of the BANG dosimeter consists of 3% w/v acrylic acid, 3% N,N'-methylene-bis-acrylamide, 1% sodium hydroxide, 5% gelatin, and 88% water. MR images are transferred via a local network to a Macintosh computer, and R2 maps constructed on the basis of multiple TE images, using a non-linear least squares fit based on the Levenberg-Marquardt algorithm. A dose-to-R2

  7. k-space sampling optimization for ultrashort TE imaging of cortical bone: applications in radiation therapy planning and MR-based PET attenuation correction.

    Science.gov (United States)

    Hu, Lingzhi; Su, Kuan-Hao; Pereira, Gisele C; Grover, Anu; Traughber, Bryan; Traughber, Melanie; Muzic, Raymond F

    2014-10-01

    using a reduced sampled UTE sequence with no visible compromise in image quality and they preserved bone-to-air contrast with as low as a 25% sampling rate. This UTE strategy with angular undersampling preserves the image quality and contrast of cortical bone, while reducing the total scanning time by as much as 75%. The quantitative results of R2(∗) and the water fraction of skull based on Dixon analysis of UTE images acquired at multiple echo times provide guidance for the clinical adoption and further parameter optimization of the UTE sequence when used for radiation therapy and MR-based PET attenuation correction.

  8. k-space sampling optimization for ultrashort TE imaging of cortical bone: Applications in radiation therapy planning and MR-based PET attenuation correction

    International Nuclear Information System (INIS)

    Hu, Lingzhi; Traughber, Melanie; Su, Kuan-Hao; Pereira, Gisele C.; Grover, Anu; Traughber, Bryan; Muzic, Raymond F. Jr.

    2014-01-01

    -enhanced images can be generated using a reduced sampled UTE sequence with no visible compromise in image quality and they preserved bone-to-air contrast with as low as a 25% sampling rate. Conclusions: This UTE strategy with angular undersampling preserves the image quality and contrast of cortical bone, while reducing the total scanning time by as much as 75%. The quantitative results of R2 ∗ and the water fraction of skull based on Dixon analysis of UTE images acquired at multiple echo times provide guidance for the clinical adoption and further parameter optimization of the UTE sequence when used for radiation therapy and MR-based PET attenuation correction

  9. On probabilistically defined margins in radiation therapy

    International Nuclear Information System (INIS)

    Papiez, Lech; Langer, Mark

    2006-01-01

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

  10. On probabilistically defined margins in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Papiez, Lech; Langer, Mark [Department of Radiation Oncology, Indiana University, Indianapolis, IN (United States)

    2006-08-21

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

  11. 21 CFR 892.5840 - Radiation therapy simulation system.

    Science.gov (United States)

    2010-04-01

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

  12. 21 CFR 892.5750 - Radionuclide radiation therapy system.

    Science.gov (United States)

    2010-04-01

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

  13. Radiation therapy with fast neutrons: A review

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  14. The physical basis and future of radiation therapy.

    Science.gov (United States)

    Bortfeld, T; Jeraj, R

    2011-06-01

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

  15. The physical basis and future of radiation therapy

    Science.gov (United States)

    Bortfeld, T; Jeraj, R

    2011-01-01

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

  16. Meningeal hemangiopericytoma treated with surgery and radiation therapy -case report-

    International Nuclear Information System (INIS)

    Jang, Ji Young; Oh, Yoon Kyeong

    2006-01-01

    Meningeal hemangiopericytoma (HPC) is an uncommon dura-based tumor and can recur not only locally but also distantly in the neural axis or extraneural sites. We report our experience of radiation therapy, one preoperative and one elective postoperative, in two patients with meningeal HPC and reviewed the role of radiation therapy. A 41-year-old man (Case 1) presented with a 3-month history of headache and right hemiparesis. The mass was nearly unresectable at the first and second operation and diagnosed as meningeal HPC. Preoperative radiation therapy was given with a total dose of 55.8 Gy/31 fractions to the large residual mass of left frontoparietal area. Follow-up computerized tomography (CT) showed marked regression of tumor after radiation therapy. The third operation was performed to remove the residual tumor at 6 months after the radiation therapy and a 2 x 2 cm sized tumor was encountered. The mass was totally removed. The serial follow-up CT showed no evidence of recurrence and he is alive without distant metastasis for 4 years and 10 months after the first operation. A 45-year-old woman (Case 2) presented with suddenly developed headache and visual impairment. Tumor mass occupying right frontal lobe was removed with the preoperative diagnosis of meningioma. It was totally removed with attached sagittal sinus and diagnosed as meningeal HPC. Elective postoperative radiation therapy was performed to reduce local recurrence with a total dose of 54 Gy/30 fractions to the involved area of right frontal lobe. She is alive for 5 years maintaining normal activity without local recurrence and distant metastasis

  17. Three-dimensional conformal radiation therapy: the tomo-therapy approach

    International Nuclear Information System (INIS)

    Linthout, N.; Verellen, D.; Coninck, P. de; Bel, A.; Storme, G.

    2000-01-01

    Conformal radiation therapy allows the possibility of delivering high doses at the tumor volume whilst limiting the dose to the surrounding tissues and diminishing the secondary effects. With the example of the conformal radiation therapy used at the AZ VU8 (3DCRT and tomo-therapy), two treatment plans of a left ethmoid carcinoma will be evaluated and discussed in detail. The treatment of ethmoid cancer is technically difficult for both radiation therapy and surgery because of the anatomic constraints and patterns of local spread. A radiation therapy is scheduled to be delivered after surgical resection of the tumor. The treatment plan for the radiation therapy was calculated on a three-dimensional (3D) treatment planning system based on virtual simulation with a beam's eye view: George Sherouse's Gratis. An effort was made to make the plan as conformal and as homogeneous as possible to deliver a dose of 66 Gy in 33 fractions at the tumor bed with a maximum dose of 56 Gy to the right optic nerve and the chiasma. To establish the clinical utility and potential advantages of tomo-therapy over 3DCRT for ethmoid carcinoma, the treatment of this patient was also planned with Peacock Plant. For both treatment plans the isodose distributions and cumulative dose volume histograms (CDVH) were computed. Superimposing the CDVHs yielded similar curves for the target and an obvious improvement for organs at risk such as the chiasma, brainstem and the left eye when applying tomo-therapy. These results have also been reflected in the tumor control probabilities (equal for both plans) and the normal tissue complication probabilities (NTCP), yielding significant reductions in NTCP for tomo-therapy. The probability of uncomplicated tumor control was 52.7% for tomo-therapy against 38.3% for 3DCRT. (authors)

  18. Quality Assurance Needs for Modern Image-Based Radiotherapy: Recommendations From 2007 Interorganizational Symposium on 'Quality Assurance of Radiation Therapy: Challenges of Advanced Technology'

    International Nuclear Information System (INIS)

    Williamson, Jeffrey F.; Dunscombe, Peter B.; Sharpe, Michael B.; Thomadsen, Bruce R.; Purdy, James A.; Deye, James A.

    2008-01-01

    This report summarizes the consensus findings and recommendations emerging from 2007 Symposium, 'Quality Assurance of Radiation Therapy: Challenges of Advanced Technology.' The Symposium was held in Dallas February 20-22, 2007. The 3-day program, which was sponsored jointly by the American Society for Therapeutic Radiology and Oncology (ASTRO), American Association of Physicists in Medicine (AAPM), and National Cancer Institute (NCI), included >40 invited speakers from the radiation oncology and industrial engineering/human factor communities and attracted nearly 350 attendees, mostly medical physicists. A summary of the major findings follows. The current process of developing consensus recommendations for prescriptive quality assurance (QA) tests remains valid for many of the devices and software systems used in modern radiotherapy (RT), although for some technologies, QA guidance is incomplete or out of date. The current approach to QA does not seem feasible for image-based planning, image-guided therapies, or computer-controlled therapy. In these areas, additional scientific investigation and innovative approaches are needed to manage risk and mitigate errors, including a better balance between mitigating the risk of catastrophic error and maintaining treatment quality, complimenting the current device-centered QA perspective by a more process-centered approach, and broadening community participation in QA guidance formulation and implementation. Industrial engineers and human factor experts can make significant contributions toward advancing a broader, more process-oriented, risk-based formulation of RT QA. Healthcare administrators need to appropriately increase personnel and ancillary equipment resources, as well as capital resources, when new advanced technology RT modalities are implemented. The pace of formalizing clinical physics training must rapidly increase to provide an adequately trained physics workforce for advanced technology RT. The specific

  19. Quality assurance needs for modern image-based radiotherapy: recommendations from 2007 interorganizational symposium on "quality assurance of radiation therapy: challenges of advanced technology".

    Science.gov (United States)

    Williamson, Jeffrey F; Dunscombe, Peter B; Sharpe, Michael B; Thomadsen, Bruce R; Purdy, James A; Deye, James A

    2008-01-01

    This report summarizes the consensus findings and recommendations emerging from 2007 Symposium, "Quality Assurance of Radiation Therapy: Challenges of Advanced Technology." The Symposium was held in Dallas February 20-22, 2007. The 3-day program, which was sponsored jointly by the American Society for Therapeutic Radiology and Oncology (ASTRO), American Association of Physicists in Medicine (AAPM), and National Cancer Institute (NCI), included >40 invited speakers from the radiation oncology and industrial engineering/human factor communities and attracted nearly 350 attendees, mostly medical physicists. A summary of the major findings follows. The current process of developing consensus recommendations for prescriptive quality assurance (QA) tests remains valid for many of the devices and software systems used in modern radiotherapy (RT), although for some technologies, QA guidance is incomplete or out of date. The current approach to QA does not seem feasible for image-based planning, image-guided therapies, or computer-controlled therapy. In these areas, additional scientific investigation and innovative approaches are needed to manage risk and mitigate errors, including a better balance between mitigating the risk of catastrophic error and maintaining treatment quality, complimenting the current device-centered QA perspective by a more process-centered approach, and broadening community participation in QA guidance formulation and implementation. Industrial engineers and human factor experts can make significant contributions toward advancing a broader, more process-oriented, risk-based formulation of RT QA. Healthcare administrators need to appropriately increase personnel and ancillary equipment resources, as well as capital resources, when new advanced technology RT modalities are implemented. The pace of formalizing clinical physics training must rapidly increase to provide an adequately trained physics workforce for advanced technology RT. The specific

  20. Y90 selective internal radiation therapy.

    Science.gov (United States)

    Lee, Edward W; Thakor, Avnesh S; Tafti, Bashir A; Liu, David M

    2015-01-01

    Primary liver malignancies and liver metastases are affecting millions of individuals worldwide. Because of their late and advanced stage presentation, only 10% of patients can receive curative surgical treatment, including transplant or resection. Alternative treatments, such as systemic chemotherapy, ablative therapy, and chemoembolization, have been used with marginal survival benefits. Selective internal radiation therapy (SIRT), also known as radioembolization, is a compelling alternative treatment option for primary and metastatic liver malignancies with a growing body of evidence. In this article, an introduction to SIRT including background, techniques, clinical outcomes, and complications is reviewed. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. A virtual radiation therapy workflow training simulation

    International Nuclear Information System (INIS)

    Bridge, P.; Crowe, S.B.; Gibson, G.; Ellemor, N.J.; Hargrave, C.; Carmichael, M.

    2016-01-01

    Aim: Simulation forms an increasingly vital component of clinical skills development in a wide range of professional disciplines. Simulation of clinical techniques and equipment is designed to better prepare students for placement by providing an opportunity to learn technical skills in a “safe” academic environment. In radiotherapy training over the last decade or so this has predominantly comprised treatment planning software and small ancillary equipment such as mould room apparatus. Recent virtual reality developments have dramatically changed this approach. Innovative new simulation applications and file processing and interrogation software have helped to fill in the gaps to provide a streamlined virtual workflow solution. This paper outlines the innovations that have enabled this, along with an evaluation of the impact on students and educators. Method: Virtual reality software and workflow applications have been developed to enable the following steps of radiation therapy to be simulated in an academic environment: CT scanning using a 3D virtual CT scanner simulation; batch CT duplication; treatment planning; 3D plan evaluation using a virtual linear accelerator; quantitative plan assessment, patient setup with lasers; and image guided radiotherapy software. Results: Evaluation of the impact of the virtual reality workflow system highlighted substantial time saving for academic staff as well as positive feedback from students relating to preparation for clinical placements. Students valued practice in the “safe” environment and the opportunity to understand the clinical workflow ahead of clinical department experience. Conclusion: Simulation of most of the radiation therapy workflow and tasks is feasible using a raft of virtual reality simulation applications and supporting software. Benefits of this approach include time-saving, embedding of a case-study based approach, increased student confidence, and optimal use of the clinical environment

  2. ARCHERRT – A GPU-based and photon-electron coupled Monte Carlo dose computing engine for radiation therapy: Software development and application to helical tomotherapy

    Science.gov (United States)

    Su, Lin; Yang, Youming; Bednarz, Bryan; Sterpin, Edmond; Du, Xining; Liu, Tianyu; Ji, Wei; Xu, X. George

    2014-01-01

    Purpose: Using the graphical processing units (GPU) hardware technology, an extremely fast Monte Carlo (MC) code ARCHERRT is developed for radiation dose calculations in radiation therapy. This paper describes the detailed software development and testing for three clinical TomoTherapy® cases: the prostate, lung, and head & neck. Methods: To obtain clinically relevant dose distributions, phase space files (PSFs) created from optimized radiation therapy treatment plan fluence maps were used as the input to ARCHERRT. Patient-specific phantoms were constructed from patient CT images. Batch simulations were employed to facilitate the time-consuming task of loading large PSFs, and to improve the estimation of statistical uncertainty. Furthermore, two different Woodcock tracking algorithms were implemented and their relative performance was compared. The dose curves of an Elekta accelerator PSF incident on a homogeneous water phantom were benchmarked against DOSXYZnrc. For each of the treatment cases, dose volume histograms and isodose maps were produced from ARCHERRT and the general-purpose code, GEANT4. The gamma index analysis was performed to evaluate the similarity of voxel doses obtained from these two codes. The hardware accelerators used in this study are one NVIDIA K20 GPU, one NVIDIA K40 GPU, and six NVIDIA M2090 GPUs. In addition, to make a fairer comparison of the CPU and GPU performance, a multithreaded CPU code was developed using OpenMP and tested on an Intel E5-2620 CPU. Results: For the water phantom, the depth dose curve and dose profiles from ARCHERRT agree well with DOSXYZnrc. For clinical cases, results from ARCHERRT are compared with those from GEANT4 and good agreement is observed. Gamma index test is performed for voxels whose dose is greater than 10% of maximum dose. For 2%/2mm criteria, the passing rates for the prostate, lung case, and head & neck cases are 99.7%, 98.5%, and 97.2%, respectively. Due to specific architecture of GPU, modified

  3. ARCHERRT - a GPU-based and photon-electron coupled Monte Carlo dose computing engine for radiation therapy: software development and application to helical tomotherapy.

    Science.gov (United States)

    Su, Lin; Yang, Youming; Bednarz, Bryan; Sterpin, Edmond; Du, Xining; Liu, Tianyu; Ji, Wei; Xu, X George

    2014-07-01

    Using the graphical processing units (GPU) hardware technology, an extremely fast Monte Carlo (MC) code ARCHERRT is developed for radiation dose calculations in radiation therapy. This paper describes the detailed software development and testing for three clinical TomoTherapy® cases: the prostate, lung, and head & neck. To obtain clinically relevant dose distributions, phase space files (PSFs) created from optimized radiation therapy treatment plan fluence maps were used as the input to ARCHERRT. Patient-specific phantoms were constructed from patient CT images. Batch simulations were employed to facilitate the time-consuming task of loading large PSFs, and to improve the estimation of statistical uncertainty. Furthermore, two different Woodcock tracking algorithms were implemented and their relative performance was compared. The dose curves of an Elekta accelerator PSF incident on a homogeneous water phantom were benchmarked against DOSXYZnrc. For each of the treatment cases, dose volume histograms and isodose maps were produced from ARCHERRT and the general-purpose code, GEANT4. The gamma index analysis was performed to evaluate the similarity of voxel doses obtained from these two codes. The hardware accelerators used in this study are one NVIDIA K20 GPU, one NVIDIA K40 GPU, and six NVIDIA M2090 GPUs. In addition, to make a fairer comparison of the CPU and GPU performance, a multithreaded CPU code was developed using OpenMP and tested on an Intel E5-2620 CPU. For the water phantom, the depth dose curve and dose profiles from ARCHERRT agree well with DOSXYZnrc. For clinical cases, results from ARCHERRT are compared with those from GEANT4 and good agreement is observed. Gamma index test is performed for voxels whose dose is greater than 10% of maximum dose. For 2%/2mm criteria, the passing rates for the prostate, lung case, and head & neck cases are 99.7%, 98.5%, and 97.2%, respectively. Due to specific architecture of GPU, modified Woodcock tracking algorithm

  4. Radiation Therapy in Elderly Skin Cancer

    International Nuclear Information System (INIS)

    Kim, Jin Hee

    2008-01-01

    To evaluate the long term results (local control, survival, failure, and complications) after radiation therapy for skin cancer in elderly patients. The study spanned from January 1990 to October 2002. Fifteen elderly patients with skin cancer were treated by radiotherapy at the Keimyung University Dongsan Medical Center. The age distribution of the patients surveyed was 72 to 95 years, with a median age of 78.8 years. The pathologic classification of the 15 patients included squamous cell carcinoma (10 patients), basal cell carcinoma (3 patients), verrucous carcinoma (1 patient) and skin adnexal origin carcinoma (1 patient). The most common tumor location was the head (13 patients). The mean tumor diameter was 4.9 cm (range 2 to 9 cm). The radiation dose was delivered via an electron beam of 6 to 15 MeV. The dose range was adjusted to the tumor diameter and depth of tumor invasion. The total radiation dose ranged from 50∼80 Gy (mean: 66 Gy) with a 2 Gy fractional dose prescribed to the 80% isodose line once a day and 5 times a week. One patient with lymph node metastasis was treated with six MV photon beams boosted with electron beams. The length of the follow-up periods ranged from 10 to 120 months with a median follow-up period of 48 months. The local control rates were 100% (15/15). In addition, the five year disease free survival rate (5YDFS) was 80% and twelve patients (80%) had no recurrence and skin cancer recurrence occurred in 3 patients (20%). Three patients have lived an average of 90 months (68∼120 months) without recurrence or metastasis. A total of 9 patients who died as a result of other causes had a mean survival time of 55.8 months after radiation therapy. No severe acute or chronic complications were observed after radiation therapy. Only minor complications including radiation dermatitis was treated with supportive care. The results suggest that radiation therapy is an effective and safe treatment method for the treatment of skin cancer in

  5. Radiation therapy for head and neck cancers

    International Nuclear Information System (INIS)

    Gillette, S.M.; Gillette, E.L.

    1995-01-01

    Radiation therapy may be indicated for larger invasive tumors of the head and neck that may be difficult to surgically excise or for which surgery would be significantly disfiguring. Previous studies of oral squamous cell carcinomas indicate that it should be possible to control approximately 80% of all but the most advanced local or locoregional tumors. Aggressive radiation therapy to total doses of 56 Gy or greater may be required. That can be done by using smaller doses per fraction and gradually reducing the size of the field so that the highest dose is given only to the tumor with a relatively tight margin. Malignant melanomas can be controlled locally apparently with a few large fractions. Metastatic disease limits survival; therefore, some type of systemic therapy seems to be needed to improve survival of those patients. Canine oral fibrosarcomas require a very high dose for a reasonable probability of control. It seems that a dose of 56 Gy given in 3.3 Gy fractions might provide local control of 50% of the tumors. It is likely that a combination of surgery and radiation would significantly improve the probability for control. Oral squamous cell carcinomas of cats must also be treated very aggressively to improve local control. Tumors of the nasal cavity are usually very large and invasive at the time of diagnosis. Radiation therapy has been shown to be effective in some instances. It is possible that with better definition of the tumor through computerized tomography imaging and improved treatment planning, control of these difficult to manage nasal tumors can be improved

  6. Targeted Radiation Therapy for Cancer Initiative

    Science.gov (United States)

    2017-11-01

    CONTRACTING ORGANIZATION: The Geneva Foundation , Tacoma, WA 98402 REPORT DATE: November 2017 TYPE OF REPORT: Final PREPARED FOR: U.S. Army Medical...ADDRESS. 1. REPORT DATE November 2017 2. REPORT TYPE Final 3. DATES COVERED 08/04/2008 - 08/03/2017 4. TITLE AND SUBTITLE Targeted Radiation Therapy...REPORT NUMBER The Geneva Foundation 917 Pacific Ave, Suite 600 Tacoma, WA 98402 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR

  7. The concept and evolution of involved site radiation therapy for lymphoma

    DEFF Research Database (Denmark)

    Specht, Lena; Yahalom, Joachim

    2015-01-01

    We describe the development of radiation therapy for lymphoma from extended field radiotherapy of the past to modern conformal treatment with involved site radiation therapy based on advanced imaging, three-dimensional treatment planning and advanced treatment delivery techniques. Today, radiation...... therapy is part of the multimodality treatment of lymphoma, and the irradiated tissue volume is much smaller than before, leading to highly significant reductions in the risks of long-term complications....

  8. Prospective observer and software-based assessment of magnetic resonance imaging quality in head and neck cancer: Should standard positioning and immobilization be required for radiation therapy applications?

    Science.gov (United States)

    Ding, Yao; Mohamed, Abdallah S R; Yang, Jinzhong; Colen, Rivka R; Frank, Steven J; Wang, Jihong; Wassal, Eslam Y; Wang, Wenjie; Kantor, Michael E; Balter, Peter A; Rosenthal, David I; Lai, Stephen Y; Hazle, John D; Fuller, Clifton D

    2015-01-01

    The purpose of this study was to investigate the potential of a head and neck magnetic resonance simulation and immobilization protocol on reducing motion-induced artifacts and improving positional variance for radiation therapy applications. Two groups (group 1, 17 patients; group 2, 14 patients) of patients with head and neck cancer were included under a prospective, institutional review board-approved protocol and signed informed consent. A 3.0-T magnetic resonance imaging (MRI) scanner was used for anatomic and dynamic contrast-enhanced acquisitions with standard diagnostic MRI setup for group 1 and radiation therapy immobilization devices for group 2 patients. The impact of magnetic resonance simulation/immobilization was evaluated qualitatively by 2 observers in terms of motion artifacts and positional reproducibility and quantitatively using 3-dimensional deformable registration to track intrascan maximum motion displacement of voxels inside 7 manually segmented regions of interest. The image quality of group 2 (29 examinations) was significantly better than that of group 1 (50 examinations) as rated by both observers in terms of motion minimization and imaging reproducibility (P quality of head and neck MRI in terms of motion-related artifacts and positional reproducibility was greatly improved by use of radiation therapy immobilization devices. Consequently, immobilization with external and intraoral fixation in MRI examinations is required for radiation therapy application. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  9. Chronic neuroendocrinological sequelae of radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-03-30

    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.

  10. Generalized Morphea after Breast Cancer Radiation Therapy

    Directory of Open Access Journals (Sweden)

    Jonathan Kushi

    2011-01-01

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

  11. Image-guided radiation therapy: physician's perspectives

    International Nuclear Information System (INIS)

    Gupta, T.; Anand Narayan, C.

    2012-01-01

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

  12. TU-H-BRA-02: The Physics of Magnetic Field Isolation in a Novel Compact Linear Accelerator Based MRI-Guided Radiation Therapy System

    International Nuclear Information System (INIS)

    Low, D; Mutic, S; Shvartsman, S; Chmielewski, T; Fought, G; Sharma, A; Dempsey, J

    2016-01-01

    Purpose: To develop a method for isolating the MRI magnetic field from field-sensitive linear accelerator components at distances close to isocenter. Methods: A MRI-guided radiation therapy system has been designed that integrates a linear accelerator with simultaneous MR imaging. In order to accomplish this, the magnetron, port circulator, radiofrequency waveguide, gun driver, and linear accelerator needed to be placed in locations with low magnetic fields. The system was also required to be compact, so moving these components far from the main magnetic field and isocenter was not an option. The magnetic field sensitive components (exclusive of the waveguide) were placed in coaxial steel sleeves that were electrically and mechanically isolated and whose thickness and placement were optimized using E&M modeling software. Six sets of sleeves were placed 60° apart, 85 cm from isocenter. The Faraday effect occurs when the direction of propagation is parallel to the magnetic RF field component, rotating the RF polarization, subsequently diminishing RF power. The Faraday effect was avoided by orienting the waveguides such that the magnetic field RF component was parallel to the magnetic field. Results: The magnetic field within the shields was measured to be less than 40 Gauss, significantly below the amount needed for the magnetron and port circulator. Additional mu-metal was employed to reduce the magnetic field at the linear accelerator to less than 1 Gauss. The orientation of the RF waveguides allowed the RT transport with minimal loss and reflection. Conclusion: One of the major challenges in designing a compact linear accelerator based MRI-guided radiation therapy system, that of creating low magnetic field environments for the magnetic-field sensitive components, has been solved. The measured magnetic fields are sufficiently small to enable system integration. This work supported by ViewRay, Inc.

  13. Parotid Glands Dose–Effect Relationships Based on Their Actually Delivered Doses: Implications for Adaptive Replanning in Radiation Therapy of Head-and-Neck Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, Klaudia U. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Fernandes, Laura L. [Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Vineberg, Karen A.; McShan, Daniel; Antonuk, Alan E. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Cornwall, Craig [Department of Hospital Dentistry, University of Michigan, Ann Arbor, Michigan (United States); Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Schipper, Mathew J. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Balter, James M. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Eisbruch, Avraham, E-mail: eisbruch@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

    2013-11-15

    Purpose: Doses actually delivered to the parotid glands during radiation therapy often exceed planned doses. We hypothesized that the delivered doses correlate better with parotid salivary output than the planned doses, used in all previous studies, and that determining these correlations will help make decisions regarding adaptive radiation therapy (ART) aimed at reducing the delivered doses. Methods and Materials: In this prospective study, oropharyngeal cancer patients treated definitively with chemoirradiation underwent daily cone-beam computed tomography (CBCT) with clinical setup alignment based on the C2 posterior edge. Parotid glands in the CBCTs were aligned by deformable registration to calculate cumulative delivered doses. Stimulated salivary flow rates were measured separately from each parotid gland pretherapy and periodically posttherapy. Results: Thirty-six parotid glands of 18 patients were analyzed. Average mean planned doses was 32 Gy, and differences from planned to delivered mean gland doses were −4.9 to +8.4 Gy, median difference +2.2 Gy in glands in which delivered doses increased relative to planned. Both planned and delivered mean doses were significantly correlated with posttreatment salivary outputs at almost all posttherapy time points, without statistically significant differences in the correlations. Large dispersions (on average, SD 3.6 Gy) characterized the dose–effect relationships for both. The differences between the cumulative delivered doses and planned doses were evident at first fraction (r=.92, P<.0001) because of complex setup deviations (eg, rotations and neck articulations), uncorrected by the translational clinical alignments. Conclusions: After daily translational setup corrections, differences between planned and delivered doses in most glands were small relative to the SDs of the dose–saliva data, suggesting that ART is not likely to gain measurable salivary output improvement in most cases. These differences were

  14. TU-H-BRA-01: The Physics of High Power Radiofrequency Isolation in a Novel Compact Linear Accelerator Based MRI Guided Radiation Therapy System

    Energy Technology Data Exchange (ETDEWEB)

    Lamb, J; Low, D [University of California, Los Angeles, Los Angeles, CA (United States); Mutic, S [Washington University School of Medicine, Saint Louis, MO (United States); Shvartsman, S; Chmielewski, T; Fought, G; Sharma, A; Dempsey, J [ViewRay, Inc., Oakwood Village, OH (United States)

    2016-06-15

    Purpose: To develop a method for isolating the radiofrequency waves emanating from linear accelerator components from the magnetic resonance imaging (MRI) system of an integrated MRI-linac. Methods: An MRI-guided radiation therapy system has been designed that integrates a linear accelerator with simultaneous MR imaging. The radiofrequency waves created by the accelerating process would degrade MR image quality, so a method for containing the radiofrequency waves and isolating the MR imager from them was developed. The linear accelerator radiofrequency modulator was placed outside the room, so a filter was designed to eliminate the radiofrequency corresponding to the proton Larmour frequency of 14.7 MHz. Placing the radiofrequency emitting components in a typical Faraday cage would have reduced the radiofrequency emissions, but the design would be susceptible to small gaps in the shield due to the efficiency of the Faraday cage reflecting internal radiofrequency emissions. To reduce internal radiofrequency reflections, the Faraday cage was lined with carbon fiber sheets. Carbon fiber has the property of attenuating the radiofrequency energy so that the overall radiofrequency field inside the Faraday cage is reduced, decreasing any radiofrequency energy emitted from small gaps in the cage walls. Results: Within a 1.2 MHz band centered on the Larmor frequency, the radiofrequency (RF) leakage from the Faraday cage was measured to be −90 dB with no RF on, −40 dB with the RF on and no shield, returning to −90 dB with the RF on and shields in place. The radiofrequency filter attenuated the linear accelerator modulator emissions in the 14.7 MHz band by 70 dB. Conclusions: One of the major challenges in designing a compact linear accelerator based MRI-guided radiation therapy system, that of isolating the high power RF system from the MRI, has been solved. The measured radiofrequency emissions are sufficiently small to enable system integration. This research was

  15. Comparison of Planning Quality and Efficiency Between Conventional and Knowledge-based Algorithms in Nasopharyngeal Cancer Patients Using Intensity Modulated Radiation Therapy.

    Science.gov (United States)

    Chang, Amy T Y; Hung, Albert W M; Cheung, Fion W K; Lee, Michael C H; Chan, Oscar S H; Philips, Helen; Cheng, Yung-Tang; Ng, Wai-Tong

    2016-07-01

    Intensity modulated radiation therapy (IMRT) is widely used to achieve a highly conformal dose and improve treatment outcome. However, plan quality and planning time are institute and planner dependent, and no standardized tool exists to recognize an optimal plan. RapidPlan, a knowledge-based algorithm, can generate constraints to assist optimization and produce high-quality IMRT plans. This report evaluated the quality and efficiency of using RapidPlan in nasopharyngeal carcinoma (NPC) IMRT planning. RapidPlan was configured using 79 radical IMRT plans for NPC; 20 consecutive NPC patients indicated for radical radiation therapy between October 2014 and May 2015 were then recruited to assess its performance. The ability of RapidPlan to produce acceptable plans was evaluated. For plans that could not achieve clinical acceptance, manual touch-up was performed. The IMRT plans produced without RapidPlan (manual plans) and with RapidPlan (RP-2 plans, including those with manual touch-up) were compared in terms of dosimetric quality and planning efficiency. RapidPlan by itself could produce clinically acceptable plans for 9 of the 20 patients; manual touch-up increased the number of acceptable plans (RP-2 plans) to 19. The target dose coverage and conformity were very similar. No difference was found in the maximum dose to the brainstem and optic chiasm. RP-2 plans delivered a higher maximum dose to the spinal cord (46.4 Gy vs 43.9 Gy, P=.002) but a lower dose to the parotid (mean dose to right parotid, 37.3 Gy vs 45.4 Gy; left, 34.4 Gy vs 43.1 Gy; Pmanual plans (64 minutes vs 295 minutes, P<.001). This study shows that RapidPlan can significantly improve planning efficiency and produce quality IMRT plans for NPC patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Quality-of-life assessment following surgery with or without postoperative radiation therapy for squamous cell carcinoma of the tongue base

    International Nuclear Information System (INIS)

    Nisi, K.W.; Earle, J.M.; Foote, R.L.

    1996-01-01

    Purpose/Objective: To evaluate the quality-of-life after surgery with or without postoperative radiation therapy for carcinoma of the tongue base. Materials and Methods: At the 1995 ASTRO meeting, the University of Florida and MSKCC reported the quality-of-life (QOL) functional outcome of patients treated with primary radiation therapy (RT) for squamous cell carcinoma of the tongue base (BOT). Relatively little data evaluating the QOL following primary surgery has been published. Between January 1974 and December 1993, 89 patients (pts) underwent surgery alone (65 pts) or surgery combined with postoperative radiation therapy (24 pts) for tongue base cancer. Twenty-seven pts were alive at last contact. Three pts have been lost to follow-up and three pts declined to participate in the QOL assessment. Twenty-one pts consented to QOL assessment. Their median follow-up is 5.4 years (range 2.0-20.8 years). These patients completed: 1) the Performance Status Scale for Head and Neck Cancer Patients (PSS), a measure of ability to eat in public, understandability of speech, and normalcy of diet (scale 0-100, best score = 100); and 2) Functional Assessment of Cancer Therapy (FACT) (scale 0-28 for physical and social well-being, and 0-20 for emotional well-being, higher number=best score). Pathologic T stage was T1-7, T2-10, T3-3, T4-1. Twenty patients had ipsilateral neck dissection and 6 had bilateral neck dissection. The 8 patients who were treated with adjuvant RT received a median dose of 60 Gy. Prior to treatment, 62% had either full or part-time employment with a median annual income of $10,000-$40,000. Results: Mean PSS scores for all patients were 82 for eating in public, 92 for understandability of speech, and 78 for normalcy of diet. Normalcy of diet was significantly better in the surgery alone group than in the adjuvant RT group (91 vs. 56, p=0.0005). The ability to eat in public (88 vs. 72, p=NS) and understandability of speech (96 vs. 84, p=NS) did not differ

  17. Radiation therapy of psoriasis and parapsoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Wiskemann, A.

    1982-09-15

    Selective UV-Phototherapy with lambda 300-320 nm (SUP) as well as oral photochemotherapy with 8-methoxy-psoralen plus UVA-radiation (PUVA intern) are very effective in clearing the lesions of the generalized psoriasis and those of the chronic forms of parapsoriasis. Being treated with 4 suberythemal doses per week psoriasis patients are free or nearly free of symptoms after averagely 6.3 weeks of SUP-therapy or after 5.3 weeks of PUVA orally. The PUVA-therapy is mainly indicated in pustular, inverse and erythrodermic psoriasis as well as in parapsoriasis en plaques and variegata. In all other forms of psoriasis and in pityriasis lichenoides-chronica, we prefer the SUP-therapy because of less acute or chronic side effects, and because of its better practicability. X-rays are indicated in psoriais of nails, grenz-rays in superficial psoriatic lesions of the face, the armpits, the genitals and the anal region.

  18. An opioid-based pain control program for head and neck cancer patients undergoing chemoradiation therapy achieves a high completion rate of radiation

    International Nuclear Information System (INIS)

    Kato, Kengo; Matsuura, Kazuto; Zenda, Sadamoto

    2011-01-01

    Appropriate supportive care is essential for intensive chemoradiation therapy (CRT), and pain management is an important supportive care for CRT for head and neck cancer. We developed an opioid-based pain control program for head and neck cancer patients undergoing CRT, and assessed its efficacy and safety. 110 head and neck cancer patients undergoing platinum-based concomitant CRT were enrolled from 10 cancer centers or university hospitals. Their pain caused by CRT was managed with a four-step opioid-based pain control program, and adverse events and usage of opioid were analyzed. 101 suitable cases of 110 patients were analyzed. 53% of cases suffered grade 3-4 mucositis. The rate of completion of radiotherapy was 99% and the rate of unplanned breaks in radiotherapy was 13%. The usage rate of opioid was 83% and the rate of compliance with the pain control program was 92%. The median maximum quantity of morphine used per day was 35 mg. No patient had to stop the opioid program or radiotherapy due to adverse effects of opioids. An opioid-based pain control program for head and neck cancer patients undergoing CRT achieves a high completion rate of radiation. (author)

  19. Radiation therapy in Africa: distribution and equipment

    International Nuclear Information System (INIS)

    Levin, C.V.; Meghzifene, A.; Gueddari, B. el

    1999-01-01

    Africa is the least developed continent as regards radiation oncology resources. The documented ASR of cancer is of the order of 1 to 2 per 1000. With improving health care this is becoming more significant. This review was undertaken to help develop priorities for the region. Radiation Oncology departments in Africa were identified and a survey of their equipment performed. These were compared to the reported situation in 1991. Population tables for the year 2000 were compared to available megavoltage machines. Of 56 countries in Africa, only 22 are confidently known to have megavoltage therapy concentrated in the southern and northern extremes of the continent. The 155 megavoltage machines operating represents over 100% increase over the past 8 years. The population served by each megavoltage machine ranges from 0.6 million to 70 million per machine. Overall, only 50% of the population have some access to Radiation Oncology services. Progress has been made in initiating radiation oncology in Ghana, Ethiopia and Namibia. There has been some increase in machines in Algeria, Egypt, Libya, Morocco and Tunisia. However, a large backlog exists for basic radiation services. (author.)

  20. Hypofractionated stereotactic radiation therapy for recurrent glioblastoma: single institutional experience

    International Nuclear Information System (INIS)

    Ciammella, Patrizia; Podgornii, Ala; Galeandro, Maria; D’Abbiero, Nunziata; Pisanello, Anna; Botti, Andrea; Cagni, Elisabetta; Iori, Mauro; Iotti, Cinzia

    2013-01-01

    Glioblastoma (GBM) is the most common malignant primary brain tumor in adults. Tumor control and survival have improved with the use of radiotherapy (RT) plus concomitant and adjuvant chemotherapy, but the prognosis remain poor. In most cases the recurrence occurs within 7–9 months after primary treatment. Currently, many approaches are available for the salvage treatment of patients with recurrent GBM, including resection, re-irradiation or systemic agents, but no standard of care exists. We analysed a cohort of patients with recurrent GBM treated with frame-less hypofractionated stereotactic radiation therapy with a total dose of 25 Gy in 5 fractions. Of 91 consecutive patients with newly diagnosed GBM treated between 2007 and 2012 with conventional adjuvant chemo-radiation therapy, 15 underwent salvage RT at recurrence. The median time interval between primary RT and salvage RT was 10.8 months (range, 6–54 months). Overall, patients undergoing salvage RT showed a longer survival, with a median survival of 33 vs. 9.9 months (p= 0.00149). Median overall survival (OS) from salvage RT was 9.5 months. No patients demonstrated clinically significant acute morbidity, and all patients were able to complete the prescribed radiation therapy without interruption. Our results suggest that hypofractionated stereotactic radiation therapy is effective and safe in recurrent GBM. However, until prospective randomized trials will confirm these results, the decision for salvage treatment should remain individual and based on a multidisciplinary evaluation of each patient

  1. Radiation therapy for superior vena cava syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hee [Keimyung University School of Medicine, Daegu (Korea, Republic of)

    2005-06-15

    We studied the effect of such variables as the symptom improvement rate, survival and prognostic factors on the treatment results of radiation therapy for Superior Vena Cava Syndrome (SVCS). From 1988 to 2003, seventy two patients with SVCS were treated with radiation therapy at the Department of Radiation Oncology, Keimyung University Dongsan Medical Center. The patients' ages ranged from 10 to 83 years old with the median age being 61, and sixty four patients were male. For the causes of the SVCS, 64 patients had lung cancer, four had metastatic lung cancer, two had malignant lymphoma and two had thymoma. The radiotherapy was delivered with 6-MV X-ray and all patients received above 900 cGy up to 6,600 cGy, with the median dose being 4,000 cGy. The follow-up periods were from 1 to 180 months with a median of 5.6 months. The main clinical manifestations were dyspnea (84.7%), facial edema (81.9%), arm edema (22.2%), neck vein distension (25%), hoarseness (12.5%) and facial plethora (5.6%). Eighty percent of patients achieved excellent to good symptom improvement and 19.4% experienced minimal improvement. The median survival period was 5.1 months, and overall survival rates were 17.7% at 2 years (2YOS) and 14.8% at five years (5YOS) for all the patients. The median survival period, the two and five year disease free survival rates were 4.3 months, 16.7% and 13.4% for the lung cancer patients, respectively. The total tumor dose was a statistically significant survival factor on the univariate analysis for the patients with lung cancer (2YSR; > 30 Gy, 25.6%, {<=} 30 Gy 6.7%, {rho} < 0.01). On the multivariated analysis, a higher total tumor dose ({rho} < 0.01) and younger age ({rho} < 0.05) were statistically significant factors of survival for the lung cancer patients. Patients with NSCLC showed better survival than did the patients with SCLC, but this was not statistically significant ({rho} > 0.05). Radiation therapy for the patients with SVCS due to

  2. A Pragmatic Evaluation of the National Cancer Institute Physician Data Query (PDQ)®-Based Brief Counseling on Cancer-Related Fatigue among Patients Undergoing Radiation Therapy.

    Science.gov (United States)

    Bauml, Joshua; Xie, Sharon X; Penn, Courtney; Desai, Krupali; Dong, Kimberly W; Bruner, Deborah Watkins; Vapiwala, Neha; Mao, Jun James

    2012-01-01

    Cancer-Related Fatigue (CRF) negatively affects quality of life among cancer patients. This study seeks to evaluate the outcome and patient receptiveness of a brief counseling program based on National Cancer Institute (NCI) PDQ® information to manage CRF when integrated into Radiation Therapy (RT). We conducted a prospective cohort study among patients undergoing non-palliative RT. Patients with stage I-III tumors and with Karnofsky score 60 or better were given a ten-minute behavioral counseling session during the first two weeks of RT. The Brief Fatigue Inventory (BFI) was administered at baseline/end of RT. Of 93 patients enrolled, 89% found the counseling useful and practical. By the end of RT, 59% reported increased exercise, 41.6% sought nutrition counseling, 72.7% prioritized daily activities, 74.4% took daytime naps, and 70.5% talked with other cancer patients. Regarding counseling, patients who had received chemotherapy prior to RT had no change in fatigue (-0.2), those who received RT alone had mild increase in fatigue (0.7, p=0.02), and those who received concurrent chemotherapy experienced a substantial increase in fatigue (3.0 to 5.2, p=0.05). Higher baseline fatigue and receipt of chemotherapy were predictive of worsened fatigue in a multivariate model (both pbrief behavioral counseling based on NCI guidelines is well accepted by patients showing an uptake in many activities to cope with CRF. Those who receive concurrent chemotherapy and with higher baseline fatigue are at risk for worsening fatigue despite of guideline-based therapy.

  3. Quantification of late complications after radiation therapy

    International Nuclear Information System (INIS)

    Jung, Horst; Beck-Bornholdt, Hans-Peter; Svoboda, Vladimir; Alberti, Winfried; Herrmann, Thomas

    2001-01-01

    Background: An increasing number of patients survive cancer after having received radiation therapy. Therefore, the occurrence of late normal tissue complications among long-term survivors is of particular concern. Methods: Sixty-three patients treated by radical surgery and irradiation for rectal carcinoma were subjected to an unconventional sandwich therapy. Preoperative irradiation was given in four fractions of 5 Gy each applied within 2 or 3 days; postoperative irradiation consisted mostly of 15x2 Gy (range, 20-40 Gy). A considerable proportion of these patients developed severe late complications (Radiother Oncol 53 (1999) 177). The data allowed a detailed analysis of complication kinetics, leading to a new model which was tested using data from the literature. Results: Data on late complications were obtained for eight different organs with a follow-up of up to 10 years. For the various organs, the percentage of patients being free from late complications, plotted as a function of time after start of radiation therapy, was adequately described by exponential regression. From the fit, the parameter p a was obtained, which is the percentage of patients at risk in a given year of developing a complication in a given organ during that year. The rate p a remained about constant with time. Following sandwich therapy, the annual incidence of complications in the bladder, ileum, lymphatic and soft tissue, and ureters was about the same (p a =10-14%/year), whereas complications in bone or dermis occurred at lower rates (4.7 or 7.5%/year, respectively). Discussion: Numerous data sets collected from published reports were analyzed in the same way. Many of the data sets studied were from patients in a series where there was a high incidence of late effects. Three types of kinetics for the occurrence of late effects after radiotherapy were identified: Type 1, purely exponential kinetics; Type 2, exponential kinetics, the slope of which decreased exponentially with time

  4. Optical Tracking Technology in Stereotactic Radiation Therapy

    International Nuclear Information System (INIS)

    Wagner, Thomas H.; Meeks, Sanford L.; Bova, Frank J.; Friedman, William A.; Willoughby, Twyla R.; Kupelian, Patrick A.; Tome, Wolfgang

    2007-01-01

    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

  5. External beam radiation therapy for prostate cancer

    International Nuclear Information System (INIS)

    Forman, Jeffrey D.

    1996-01-01

    Purpose/Objectives: The intent of this course is to review the issues involved in the management of non-metastatic adenocarcinoma of the prostate. -- The value of pre-treatment prognostic factors including stage, grade and PSA value will be presented, and their value in determining therapeutic strategies will be discussed. -- Controversies involving the simulation process and treatment design will be presented. The value of CT scanning, Beams-Eye View, 3-D planning, intravesicle, intraurethral and rectal contrast will be presented. The significance of prostate and patient movement and strategies for dealing with them will be presented. -- The management of low stage, low to intermediate grade prostate cancer will be discussed. The dose, volume and timing of irradiation will be discussed as will the role of neo-adjuvant hormonal therapy, neutron irradiation and brachytherapy. The current status of radical prostatectomy and cryotherapy will be summarized. Treatment of locally advanced, poorly differentiated prostate cancer will be presented including a discussion of neo-adjuvant and adjuvant hormones, dose-escalation and neutron irradiation. -- Strategies for post-radiation failures will be presented including data on cryotherapy, salvage prostatectomy and hormonal therapy (immediate, delayed and/or intermittent). New areas for investigation will be reviewed. -- The management of patients post prostatectomy will be reviewed. Data on adjuvant radiation and therapeutic radiation for biochemical or clinically relapsed patients will be presented. This course hopes to present a realistic and pragmatic overview for treating patients with non-metastatic prostatic cancer

  6. Reduction of treatment breaks and radiation-induced esophagitis and pneumonitis using amifostine in unresectable non-small cell lung cancer patients receiving definitive concurrent chemotherapy and radiation therapy: a prospective community-based clinical trial.

    Science.gov (United States)

    Wynn, Raymond B; Mehta, Vivek

    2005-04-01

    Concurrent chemotherapy with daily thoracic radiation therapy is a common regimen used in patients with non-small cell lung cancer resulting in excellent response rates but with appreciable morbidity. Radiation-induced toxicities may increase the number of treatment breaks and then may limit the use of this aggressive treatment approach for some patients. We are conducting an open-label, multicenter trial determining the incidence of radiation treatment breaks and severity of treatment-related toxicities with the concurrent use of a cytoprotective agent. Approximately 15 to 20 sites in the United States will participate with a total of 200 patients. Patients will receive one of two chemotherapy regimens and daily radiation (1.8 to 2.0 Gy daily; total dose, 60 to 70 Gy) and amifostine 500 mg subcutaneously or intravenous push daily over a 6- to 7-week period. Patients will receive amifostine (Ethyol; MedImmune Inc, Gaithersburg, MD) 500 mg daily. The route of amifostine administration chosen at the time of patient registration must be adhered to throughout the study. In addition, all patients may receive consolidation chemotherapy consisting of intravenous docetaxel 75 mg/m 2 once every 3 weeks for three courses, starting more than 30 but less than 60 days after the last dose of amifostine or thoracic radiation therapy, whichever is the last therapy discontinued. The objectives of this study are to determine the incidence of radiation treatment breaks and evaluate acute radiation esophagitis, acute radiation pneumonitis, chronic radiation pneumonitis, and pulmonary function in patients with measurable, medically inoperable non-small cell lung cancer stage II, unresectable stage IIIA, or IIIB disease receiving combined modality therapy and amifostine.

  7. Selective internal radiation therapy for liver malignancies.

    Science.gov (United States)

    Moir, J A G; Burns, J; Barnes, J; Colgan, F; White, S A; Littler, P; Manas, D M; French, J J

    2015-11-01

    Selective internal radiation therapy (SIRT) is a non-ablative technique for the treatment of liver primaries and metastases, with the intention of reducing tumour bulk. This study aimed to determine optimal patient selection, and elucidate its role as a downsizing modality. Data were collected retrospectively on patients who underwent SIRT between 2011 and 2014. The procedure was performed percutaneously by an expert radiologist. Response was analysed in two categories, based on radiological (CT/MRI according to Response Evaluation Criteria In Solid Tumours (RECIST)) and biological (α-fetoprotein, carcinoembryonic antigen, carbohydrate antigen 19-9, chromogranin A) parameters. Forty-four patients were included. Liver metastases from colorectal cancer (22 patients) and hepatocellular carcinoma (HCC) (9) were the most common pathologies. Radiological response data were collected from 31 patients. A reduction in sum of diameters (SOD) was observed in patients with HCC (median -24.1 (95 per cent c.i. -43.4 to -3.8) per cent) and neuroendocrine tumours (-30.0 (-45.6 to -7.7) per cent), whereas a slight increase in SOD was seen in patients with colorectal cancer (4.9 (-10.6 to 55.3) per cent). Biological response was assessed in 17 patients, with a reduction in 12, a mixed response in two and no improvement in three. Six- and 12-month overall survival rates were 71 and 41 per cent respectively. There was no difference in overall survival between the RECIST response groups (median survival 375, 290 and 214 days for patients with a partial response, stable disease and progressive disease respectively; P = 0.130), or according to primary pathology (P = 0.063). Seven patients underwent liver resection with variable responses after SIRT. SIRT may be used to downsize tumours and may be used as a bridge to surgery in patients with tumours deemed borderline for resection. © 2015 BJS Society Ltd Published by John Wiley & Sons Ltd.

  8. Oral care of the cancer patient receiving radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Holtzhausen, T. (Medical Univ. of Southern Africa, Pretoria (South Africa). Dept. of Community Dentistry)

    1982-07-01

    Radiation therapy is frequently being used for the patient with oral cancer. The survival rate is increasing, due to more effective treatment technique. The question of whether any teeth should be extracted, the mode of therapy and the side effects of radiation like Xerostomia, caries, stomatitis, trismus and osteo-radionecrosis and also post radiation care are discussed.

  9. Oral care of the cancer patient receiving radiation therapy

    International Nuclear Information System (INIS)

    Holtzhausen, T.

    1982-01-01

    Radiation therapy is frequently being used for the patient with oral cancer. The survival rate is increasing, due to more effective treatment technique. The question of whether any teeth should be extracted, the mode of therapy and the side effects of radiation like Xerostomia, caries, stomatitis, trismus and osteo-radionecrosis and also post radiation care are discussed

  10. Two component-theory and radiation therapy

    International Nuclear Information System (INIS)

    Wideroee, R.

    1990-01-01

    The two component theory which describes the biological effect of X-ray and particle irradiation divides radiation into densely ionizing radiation (ion density in water greater than four ions per 100 A, i.e. LET>12 keV/μm) und loosely ionizing radiation with low ion densities. In case of densely ionizing radiation, the ions can produce breaks of both cords of DNA thus causing the death of the cell (α effect). Lower ion densities will produce only slight damages which are possibly lethal but can be partly repaired (β effect). If the cell parameters are known (L. Cohen 1983), the number of surviving cells after an irradiation can be calculated. The surviving lung cells and tumor cells (squamous cell carcinoma) have been calculated for a pulmonary irradiation with 30 MeV electrons and 200 keV X-rays (single doses of 2 and 5 Gy), respectively. The electron irradiation with single doses of 5 Gy turned out to be the most favorable therapy sparing the greatest number of lung cells and reducing the tumor cells in the most effective way (down to 1.6x10 -10 ). (orig.) [de

  11. Radiation therapy in the treatment of hilar cholangiocarcinoma

    International Nuclear Information System (INIS)

    Jing Jin; Zhai Renyou

    2007-01-01

    The incidence of hilar cholangiocarcinoma is very rare worldwide. Radical resection is the only prognostic factor for long survival in patients with hilar cholangiocarcinoma. Postoperative radiation therapy can improve local control and survival rates for patients with palliative resection, but it remains controversial in patients with radical resection. Biliary drainage can effectively release bile duct obstruction for the majority of patients with locally advanced disease, and may even prolong survival when combined with radiation therapy. Radiation therapy includes extrernal beam therapy alone, external beam therapy with intraluminal brachytheapy and new radiation technique, such as three dimentional conformal therapy and intensity modulated radiation therapy. The propective randomized clinical study is needed for further investigation in the role of combined modality therapy especially for hilar cholangiocarcinoma. (authors)

  12. Treatment of arterial lesions after radiation therapy

    International Nuclear Information System (INIS)

    Bergqvist, D.; Jonsson, K.; Nilsson, M.; Takolander, R.

    1987-01-01

    Of 1,724 patients who underwent peripheral vascular operation, 12 (0.7 per cent) underwent radiation therapy of the areas including the relevant arteries one and one-half to 28 years (a mean of 15 years) previously; one patient had carcinoma of the breast, three had tumors of the neck and eight patients had malignant gynecologic disease. One patient with an occluded carotid artery was not actively treated, two underwent percutaneous transluminal angioplasty and the remaining patients underwent different types of vascular reconstructions. These patients frequently have other radiation lesions as well with involvement of the skin, bladder or intestine, which may make them problematic from a surgical point of view. Extra-anatomic reconstructions or percutaneous transluminal angioplasty can be recommended. One patient died of malignant disease three years after arterial operation. Otherwise, the results of follow-up study for these patients did not differ from other patients who underwent arterial reconstruction

  13. Radiation therapy for carcinoma of the eyelid

    International Nuclear Information System (INIS)

    Tsuchiya, Miwako; Takahashi, Mitsuhiro; Shinozaki, Jun; Kaneda, Koichi; Oda, Norio; Tabuchi, Yoshiko

    1987-01-01

    Between 1969 and 1985, 30 patients with carcinomas of the eyelid were treated by radiation, including 19 primary cases and 11 secondary cases. The latter were less controlable than the former. According to histology, there were 21 squamous cell carcinomas, 6 basal cell carcinomas and 3 adenocarcinomas. Among the 21 patients with squamous cell carcinomas, 5 had local recurrences, 10 had lymph node metastasis and 3 had distant metastasis. Patients with other histological classifications had no local recurrences, except for one who received incomplete therapy due to diabetes. Almost all of the controlled patients with squamous cell carcinomas were treated with a TDF value greater than 90. Although the visual function was damaged by irradiation in seven patients, the lesions of 6 of them were too advanced to avoid radiation injuries. (author)

  14. TH-C-17A-02: New Radioluminescence Strategies Based On CRET (Cerenkov Radiation Energy Transfer) for Imaging and Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Volotskova, O; Sun, C; Pratx, G; Xing, L [Stanford University, Stanford, CA (United States)

    2014-06-15

    Purpose: Cerenkov photons are produced when charged particles, emitted from radionuclides, travel through a media with a speed greater than that of the light in the media. Cerenkov radiation is mostly in the UV/Blue region and, thus, readily absorbed by biological tissue. Cerenkov Radiation Energy Transfer (CRET) is a wavelength-shifting phenomenon from blue Cerenkov light to more penetrating red wavelengths. We demonstrate the feasibility of in-depth imaging of CRET light originating from radionuclides realized by down conversion of gold nanoclusters (AuNCs, a novel particle composed of few atoms of gold coated with serum proteins) in vivo. Methods: Bovine Serum Albumin, Human Serum Albumin and Transferrin conjugated gold nanoclusters were synthesized, characterized and examined for CRET. Three different clinically used radiotracers: 18F-FDG, 90Y and 99mTc were used. Optical spectrum (440–750 nm) was recorded by sensitive bioluminescence imaging system at physiological temperature. Dose dependence (activity range from 0.5 up to 800uCi) and concentration dependence (0.01 to 1uM) studies were carried out. The compound was also imaged in a xenograft mouse model. Results: Only β+ and β--emitting radionuclides (18F-FDG, 90Y) are capable of CRET; no signal was found in 99mTc (γ-emitter). The emission peak of CRET by AuNCs was found to be ∼700 nm and was ∼3 fold times of background. In vitro studies showed a linear dependency between luminescence intensity and dose and concentration. CRET by gold nanoclusters was observed in xenografted mice injected with 100uCi of 18F-FDG. Conclusion: The unique optical, transport and chemical properties of AuNCs (gold nanoclusters) make them ideal candidates for in-vivo imaging applications. Development of new molecular imaging probes will allow us to achieve substantially improved spatiotemporal resolution, sensitivity and specificity for tumor imaging and detection.

  15. Impact of radiation therapy for benign diseases

    International Nuclear Information System (INIS)

    Kantor, G.; Van Houtte, P.; Beauvois, S.; Roelandts, M.

    1997-01-01

    Radiation therapy of benign diseases represent a wide panel of indications. Some indications are clearly identified as treatment of arteriovenous malformations (AVM), hyperthyroid ophthalmopathy, postoperative heterotopic bone formations or keloid scars. Some indications are under evaluation as complications induced by neo-vessels of age-related macular degeneration or coronary restenosis after angioplasty. Some indications remain controversial with poor evidence of efficiency as treatment of bursitis, tendinitis or Dupuytren's disease. Some indications are now obsolete such as warts, or contra-indicated as treatment of infant and children. (authors)

  16. Modern Radiation Therapy and Cardiac Outcomes in Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Boero, Isabel J.; Paravati, Anthony J.; Triplett, Daniel P.; Hwang, Lindsay; Matsuno, Rayna K.; Gillespie, Erin F.; Yashar, Catheryn M.; Moiseenko, Vitali; Einck, John P.; Mell, Loren K. [Department of Radiation Medicine and Applied Sciences, Moores Cancer Center, University of California, San Diego, La Jolla, California (United States); Parikh, Sahil A. [University Hospitals Case Medical Center, Harrington Heart and Vascular Institute, and Case Western Reserve University School of Medicine, Cleveland, Ohio (United States); Murphy, James D., E-mail: j2murphy@ucsd.edu [Department of Radiation Medicine and Applied Sciences, Moores Cancer Center, University of California, San Diego, La Jolla, California (United States)

    2016-03-15

    Purpose: Adjuvant radiation therapy, which has proven benefit against breast cancer, has historically been associated with an increased incidence of ischemic heart disease. Modern techniques have reduced this risk, but a detailed evaluation has not recently been conducted. The present study evaluated the effect of current radiation practices on ischemia-related cardiac events and procedures in a population-based study of older women with nonmetastatic breast cancer. Methods and Materials: A total of 29,102 patients diagnosed from 2000 to 2009 were identified from the Surveillance, Epidemiology, and End Results–Medicare database. Medicare claims were used to identify the radiation therapy and cardiac outcomes. Competing risk models were used to assess the effect of radiation on these outcomes. Results: Patients with left-sided breast cancer had a small increase in their risk of percutaneous coronary intervention (PCI) after radiation therapy—the 10-year cumulative incidence for these patients was 5.5% (95% confidence interval [CI] 4.9%-6.2%) and 4.5% (95% CI 4.0%-5.0%) for right-sided patients. This risk was limited to women with previous cardiac disease. For patients who underwent PCI, those with left-sided breast cancer had a significantly increased risk of cardiac mortality with a subdistribution hazard ratio of 2.02 (95% CI 1.23-3.34). No other outcome, including cardiac mortality for the entire cohort, showed a significant relationship with tumor laterality. Conclusions: For women with a history of cardiac disease, those with left-sided breast cancer who underwent radiation therapy had increased rates of PCI and a survival decrement if treated with PCI. The results of the present study could help cardiologists and radiation oncologists better stratify patients who need more aggressive cardioprotective techniques.

  17. Modern Radiation Therapy and Cardiac Outcomes in Breast Cancer

    International Nuclear Information System (INIS)

    Boero, Isabel J.; Paravati, Anthony J.; Triplett, Daniel P.; Hwang, Lindsay; Matsuno, Rayna K.; Gillespie, Erin F.; Yashar, Catheryn M.; Moiseenko, Vitali; Einck, John P.; Mell, Loren K.; Parikh, Sahil A.; Murphy, James D.

    2016-01-01

    Purpose: Adjuvant radiation therapy, which has proven benefit against breast cancer, has historically been associated with an increased incidence of ischemic heart disease. Modern techniques have reduced this risk, but a detailed evaluation has not recently been conducted. The present study evaluated the effect of current radiation practices on ischemia-related cardiac events and procedures in a population-based study of older women with nonmetastatic breast cancer. Methods and Materials: A total of 29,102 patients diagnosed from 2000 to 2009 were identified from the Surveillance, Epidemiology, and End Results–Medicare database. Medicare claims were used to identify the radiation therapy and cardiac outcomes. Competing risk models were used to assess the effect of radiation on these outcomes. Results: Patients with left-sided breast cancer had a small increase in their risk of percutaneous coronary intervention (PCI) after radiation therapy—the 10-year cumulative incidence for these patients was 5.5% (95% confidence interval [CI] 4.9%-6.2%) and 4.5% (95% CI 4.0%-5.0%) for right-sided patients. This risk was limited to women with previous cardiac disease. For patients who underwent PCI, those with left-sided breast cancer had a significantly increased risk of cardiac mortality with a subdistribution hazard ratio of 2.02 (95% CI 1.23-3.34). No other outcome, including cardiac mortality for the entire cohort, showed a significant relationship with tumor laterality. Conclusions: For women with a history of cardiac disease, those with left-sided breast cancer who underwent radiation therapy had increased rates of PCI and a survival decrement if treated with PCI. The results of the present study could help cardiologists and radiation oncologists better stratify patients who need more aggressive cardioprotective techniques.

  18. Dose calculation algorithms for radiation therapy with an MRI-Integrated radiation device

    International Nuclear Information System (INIS)

    Pfaffenberger, Asja

    2013-01-01

    Image-guided adaptive radiation therapy (IGART) aims at improving therapy outcome on the basis of more precise knowledge of the anatomical and physiological situation during treatment. By integration of magnetic resonance imaging (MRI), better differentiation is possible between the target volume to be irradiated and healthy surrounding tissues. In addition, changes that occur either between or during treatment fractions can be taken into account. On the basis of this information, a better conformation of radiation dose to the target volume may be achieved, which may in turn improve prognosis and reduce radiation side effects. This requires a precise calculation of radiation dose in a magnetic field that is present in these integrated irradiation devices. Real-time adaptation of the treatment plan is aimed at for which fast dose calculation is needed. Kernel-based methods are good candidates to achieve short calculation times; however, they presently only exist for radiation therapy in the absence of magnetic fields. This work suggests and investigates two approaches towards kernel-based dose calculation algorithms. One of them is integrated into treatment plan optimisation and applied to four clinical cases.

  19. MO-D-BRB-09: Treatment Delivery QA for Online Adaptive Radiation Therapy Based on Dynamic Machine Information (DMI): A Feasibility Study.

    Science.gov (United States)

    Li, T; Yuan, L; Wu, Q; Yin, F; Wu, Q J

    2012-06-01

    To implement a quality assurance (QA) system for the treatment delivery of online adaptive radiation therapy utilizing Dynamic Machine Information (DMI). DMI provides the expected/actual MLC leaf-positions, delivered MU, and beam-on status every 50ms during delivery. In this study a stream of DMI inputs is simulated by playing back Dynalog information recorded while delivering a test fluence map (FM). Based on these DMI inputs, the QA system performs three levels of monitoring/verification on the plan delivery process: (1) Following each input, actual and expected FMs delivered up to the current MLC position is dynamically updated using corresponding MLC positions in the DMI. The magnitude and frequency of pixel-by-pixel fluence differences between these two FMs are calculated and visualized in histograms.(2) At each control point, actual MLC positions are verified against the treatment plan for potential errors in data transfer between the treatment planning system (TPS) and the MLC controller.(3) Both (1) and (2) can signal beam-hold with a user-specified error tolerance.(4) After treatment, delivered dose is reconstructed in TPS based on DMI data during delivery, and compared to planned dose. (1) Efficiency: Average latency from DMI input to the completion of fluence difference calculation is Varian) Research partially supported by Varian Medical Systems. © 2012 American Association of Physicists in Medicine.

  20. Results of radiation therapy on cervical cancer

    International Nuclear Information System (INIS)

    Mitsuhashi, Norio; Nagai, Teruo; Yamakawa, Michitaka; Tsuchiya, Miwako; Takahashi, Mitsuhiro; Niibe, Hideo

    1989-01-01

    Between 1969 and 1985, a total of 298 patients with cervical cancer were treated by radiation therapy at the Department of Radiology, Gunma University Hospital. Another 111 patients were treated with irradiation as a follow up to surgery; 69 for prophylactic reasons and 42 to treat residual tumors. Patients treated with irradiation alone were given a combination of external irradiation to the pelvis and low dose rate intracavitary irradiation. Patients treated post-operatively were given intracavitary electron beam irradiation of the resected end of the vagina, and external irradiation of the entire pelvis. The following results were obtained: In patients treated by radiation therapy alone, the relative 5-year survival rates according to clinical stage were: 108% for patients with stage I cancer, 90% for stage II, 62% for stage III, and 31% for stage IV. Stage IV patients with no evidence of hematogenous metastasis could be candidates for radical therapy. Local recurrence was observed in 13% of stage II and III patients, attributed to inadequate intracavitary treatment and the histological diagnosis of adenocarcinoma. Severe complications occurred in only 12 (4%) of the 298 patients treated with irradiation alone. The relative 5-year survival rates for patients treated with post-operative irradiation were 91% for patients treated prophylactically and 49% for patients treated for residual tumor. Patients treated with post-operative irradiation for residual tumor at the resected end of the vagina showed a high cumulative survival rate of 77%. Since urinary sequelae developed in only 4 patients, it would seem that electron beam irradiation of the resected end of the vagina is a safe and effective method of therapy. (author)

  1. Gene expression profiles in cervical cancer with radiation therapy alone and chemo-radiation therapy

    International Nuclear Information System (INIS)

    Lee, Kyu Chan; Kim, Joo Young; Hwang, You Jin; Kim, Meyoung Kon; Choi, Myung Sun; Kim, Chul Young

    2003-01-01

    To analyze the gene expression profiles of uterine cervical cancer, and its variation after radiation therapy, with or without concurrent chemotherapy, using a cDNA microarray. Sixteen patients, 8 with squamous cell carcinomas of the uterine cervix, who were treated with radiation alone, and the other 8 treated with concurrent chemo-radiation, were included in the study. Before the starting of the treatment, tumor biopsies were carried out, and the second time biopsies were performed after a radiation dose of 16.2-27 Gy. Three normal cervix tissues were used as a control group. The microarray experiments were performed with 5 groups of the total RNAs extracted individually and then admixed as control, pre-radiation therapy alone, during-radiation therapy alone, pre-chemoradiation therapy, and during chemoradiation therapy. The 33P-labeled cDNAs were synthesized from the total RNAs of each group, by reverse transcription, and then they were hybridized to the cDNA microarray membrane. The gene expression of each microarrays was captured by the intensity of each spot produced by the radioactive isotopes. The pixels per spot were counted with an Arrayguage, and were exported to Microsoft Excel. The data were normalized by the Z transformation, and the comparisons were performed on the Z-ratio values calculated. The expressions of 15 genes, including integrin linked kinase (ILK), CDC28 protein kinase 2, Spry 2, and ERK 3, were increased with the Z-ratio values of over 2.0 for the cervix cancer tissues compared to those for the normal controls. Those genes were involved in cell growth and proliferation, cell cycle control, or signal transduction. The expressions of the other 6 genes, including G protein coupled receptor kinase 6, were decreased with the Z-ratio values of below -2.0. After the radiation therapy, most of the genes, with a previously increase expressions, represented the decreased expression profiles, and the genes, with the Z-ratio values of over 2.0, were

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

    International Nuclear Information System (INIS)

    Rosenthal, C.J.; Rotman, M.

    1986-01-01

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

  3. A Comparison of Evidence-Based Estimates and Empirical Benchmarks of the Appropriate Rate of Use of Radiation Therapy in Ontario

    International Nuclear Information System (INIS)

    Mackillop, William J.; Kong, Weidong; Brundage, Michael; Hanna, Timothy P.; Zhang-Salomons, Jina; McLaughlin, Pierre-Yves; Tyldesley, Scott

    2015-01-01

    Purpose: Estimates of the appropriate rate of use of radiation therapy (RT) are required for planning and monitoring access to RT. Our objective was to compare estimates of the appropriate rate of use of RT derived from mathematical models, with the rate observed in a population of patients with optimal access to RT. Methods and Materials: The rate of use of RT within 1 year of diagnosis (RT 1Y ) was measured in the 134,541 cases diagnosed in Ontario between November 2009 and October 2011. The lifetime rate of use of RT (RT LIFETIME ) was estimated by the multicohort utilization table method. Poisson regression was used to evaluate potential barriers to access to RT and to identify a benchmark subpopulation with unimpeded access to RT. Rates of use of RT were measured in the benchmark subpopulation and compared with published evidence-based estimates of the appropriate rates. Results: The benchmark rate for RT 1Y , observed under conditions of optimal access, was 33.6% (95% confidence interval [CI], 33.0%-34.1%), and the benchmark for RT LIFETIME was 41.5% (95% CI, 41.2%-42.0%). Benchmarks for RT LIFETIME for 4 of 5 selected sites and for all cancers combined were significantly lower than the corresponding evidence-based estimates. Australian and Canadian evidence-based estimates of RT LIFETIME for 5 selected sites differed widely. RT LIFETIME in the overall population of Ontario was just 7.9% short of the benchmark but 20.9% short of the Australian evidence-based estimate of the appropriate rate. Conclusions: Evidence-based estimates of the appropriate lifetime rate of use of RT may overestimate the need for RT in Ontario

  4. Dose linearity and uniformity of a linear accelerator designed for implementation of multileaf collimation system-based intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Saw, Cheng B.; Li Sicong; Ayyangar, Komanduri M.; Yoe-Sein, Maung; Pillai, Susha; Enke, Charles A.; Celi, Juan C.

    2003-01-01

    The dose linearity and uniformity of a linear accelerator designed for multileaf collimation system- (MLC) based IMRT was studied as a part of commissioning and also in response to recently published data. The linear accelerator is equipped with a PRIMEVIEW, a graphical interface and a SIMTEC IM-MAXX, which is an enhanced autofield sequencer. The SIMTEC IM-MAXX sequencer permits the radiation beam to be 'ON' continuously while delivering intensity modulated radiation therapy subfields at a defined gantry angle. The dose delivery is inhibited when the electron beam in the linear accelerator is forced out of phase with the microwave power while the MLC configures the field shape of a subfield. This beam switching mechanism reduces the overhead time and hence shortens the patient treatment time. The dose linearity, reproducibility, and uniformity were assessed for this type of dose delivery mechanism. The subfields with monitor units ranged from 1 MU to 100 MU were delivered using 6 MV and 23 MV photon beams. The doses were computed and converted to dose per monitor unit. The dose linearity was found to vary within 2% for both 6 MV and 23 MV photon beam using high dose rate setting (300 MU/min) except below 2 MU. The dose uniformity was assessed by delivering 4 subfields to a Kodak X-OMAT TL film using identical low monitor units. The optical density was converted to dose and found to show small variation within 3%. Our results indicate that this linear accelerator with SIMTEC IM-MAXX sequencer has better dose linearity, reproducibility, and uniformity than had been reported

  5. Intensity-modulated radiation therapy: dynamic MLC (DMLC) therapy, multisegment therapy and tomotherapy. An example of QA in DMLC therapy

    International Nuclear Information System (INIS)

    Webb, S.

    1998-01-01

    Intensity-modulated radiation therapy will make a quantum leap in tumor control. It is the new radiation therapy for the new millennium. The major methods to achieve IMRT are: 1. Dynamic multileaf collimator (DMLC) therapy, 2. multisegment therapy, and 3. tomotherapy. The principles of these 3 techniques are briefly reviewed. Each technique presents unique QA issues which are outlined. As an example this paper will present the results of a recent new study of an important QA concern in DMLC therapy. (orig.) [de

  6. Mapping the literature of radiation therapy.

    Science.gov (United States)

    Delwiche, Frances A

    2013-04-01

    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. 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. 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. 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.

  7. Image Guidance and Assessment of Radiation Induced Gene Therapy

    National Research Council Canada - National Science Library

    Pelizzari, Charles

    2004-01-01

    Image guidance and assessment techniques are being developed for combined radiation/gene therapy, which utilizes a radiation-inducible gene promoter to cause expression of tumor necrosis factor alpha...

  8. Comparison of Planning Quality and Efficiency Between Conventional and Knowledge-based Algorithms in Nasopharyngeal Cancer Patients Using Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Amy T.Y., E-mail: changty@ha.org.hk [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Hung, Albert W.M. [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Cheung, Fion W.K.; Lee, Michael C.H. [Department of Medical Physics, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Chan, Oscar S.H. [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Philips, Helen; Cheng, Yung-Tang [Varian Medical Systems, Palo Alto, California (United States); Ng, Wai-Tong [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong)

    2016-07-01

    Purpose: Intensity modulated radiation therapy (IMRT) is widely used to achieve a highly conformal dose and improve treatment outcome. However, plan quality and planning time are institute and planner dependent, and no standardized tool exists to recognize an optimal plan. RapidPlan, a knowledge-based algorithm, can generate constraints to assist optimization and produce high-quality IMRT plans. This report evaluated the quality and efficiency of using RapidPlan in nasopharyngeal carcinoma (NPC) IMRT planning. Methods and Materials: RapidPlan was configured using 79 radical IMRT plans for NPC; 20 consecutive NPC patients indicated for radical radiation therapy between October 2014 and May 2015 were then recruited to assess its performance. The ability of RapidPlan to produce acceptable plans was evaluated. For plans that could not achieve clinical acceptance, manual touch-up was performed. The IMRT plans produced without RapidPlan (manual plans) and with RapidPlan (RP-2 plans, including those with manual touch-up) were compared in terms of dosimetric quality and planning efficiency. Results: RapidPlan by itself could produce clinically acceptable plans for 9 of the 20 patients; manual touch-up increased the number of acceptable plans (RP-2 plans) to 19. The target dose coverage and conformity were very similar. No difference was found in the maximum dose to the brainstem and optic chiasm. RP-2 plans delivered a higher maximum dose to the spinal cord (46.4 Gy vs 43.9 Gy, P=.002) but a lower dose to the parotid (mean dose to right parotid, 37.3 Gy vs 45.4 Gy; left, 34.4 Gy vs 43.1 Gy; P<.001) and the right cochlea (mean dose, 48.6 Gy vs 52.6 Gy; P=.02). The total planning time for RP-2 plans was significantly less than that for manual plans (64 minutes vs 295 minutes, P<.001). Conclusions: This study shows that RapidPlan can significantly improve planning efficiency and produce quality IMRT plans for NPC patients.

  9. Comparison of Planning Quality and Efficiency Between Conventional and Knowledge-based Algorithms in Nasopharyngeal Cancer Patients Using Intensity Modulated Radiation Therapy

    International Nuclear Information System (INIS)

    Chang, Amy T.Y.; Hung, Albert W.M.; Cheung, Fion W.K.; Lee, Michael C.H.; Chan, Oscar S.H.; Philips, Helen; Cheng, Yung-Tang; Ng, Wai-Tong

    2016-01-01

    Purpose: Intensity modulated radiation therapy (IMRT) is widely used to achieve a highly conformal dose and improve treatment outcome. However, plan quality and planning time are institute and planner dependent, and no standardized tool exists to recognize an optimal plan. RapidPlan, a knowledge-based algorithm, can generate constraints to assist optimization and produce high-quality IMRT plans. This report evaluated the quality and efficiency of using RapidPlan in nasopharyngeal carcinoma (NPC) IMRT planning. Methods and Materials: RapidPlan was configured using 79 radical IMRT plans for NPC; 20 consecutive NPC patients indicated for radical radiation therapy between October 2014 and May 2015 were then recruited to assess its performance. The ability of RapidPlan to produce acceptable plans was evaluated. For plans that could not achieve clinical acceptance, manual touch-up was performed. The IMRT plans produced without RapidPlan (manual plans) and with RapidPlan (RP-2 plans, including those with manual touch-up) were compared in terms of dosimetric quality and planning efficiency. Results: RapidPlan by itself could produce clinically acceptable plans for 9 of the 20 patients; manual touch-up increased the number of acceptable plans (RP-2 plans) to 19. The target dose coverage and conformity were very similar. No difference was found in the maximum dose to the brainstem and optic chiasm. RP-2 plans delivered a higher maximum dose to the spinal cord (46.4 Gy vs 43.9 Gy, P=.002) but a lower dose to the parotid (mean dose to right parotid, 37.3 Gy vs 45.4 Gy; left, 34.4 Gy vs 43.1 Gy; P<.001) and the right cochlea (mean dose, 48.6 Gy vs 52.6 Gy; P=.02). The total planning time for RP-2 plans was significantly less than that for manual plans (64 minutes vs 295 minutes, P<.001). Conclusions: This study shows that RapidPlan can significantly improve planning efficiency and produce quality IMRT plans for NPC patients.

  10. Selective use of adjuvant radiation therapy in resectable colorectal adenocarcinoma

    International Nuclear Information System (INIS)

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

    1981-01-01

    Colorectal cancer recurs within the operative field in 10-20 per cent of patients undergoing potentially curative surgery. In certain subgroups, the recurrence rate is 20-50 per cent. There are some data to suggest either preoperative or postoperative radiation therapy as an adjuvant to potentially curative surgery can reduce the local operative failure rate. However, since radiation therapy has significant side effects, patient selection to maximize the therapeutic ratio is important. This report defines the criteria at the Massachusetts General Hospital for selection of patients with colorectal cancer for adjuvant radiation therapy, defines radiation therapy-surgery sequencing alternatives used, and describes techniques to reduce radiation side effects. Over a period of three and a half years, 196 patients received adjuvant radiation therapy: 51 patients received either moderate or low dose preoperative radiation therapy to rectal or rectosigmoid cancers, and 161 patients received postoperative radiation therapy to the pelvis or extrapelvic colonic tumor-lymph node beds. Some patients who received low-dose preoperative radiation therapy also received moderate-dose postoperative radiation therapy. We prefer moderate-dose postoperative radiation therapy as the approach most likely to decrease the local recurrence rate with minimal interference with surgical procedures and late small-bowel complications. Patients who received postoperative radiation therapy were those without distant metastases, whose primary tumor pathology revealed macroscopic or extensive microscopic transmural tumor penetration into extraperitoneal tissues. Careful case selection, multiple field techniques, the use of reperitonealization, omental flaps, and retroversion of the uterus into the pelvis were combined with postoperative small-bowel x-rays, bladder distention, and lateral portals to minimize radiation damage to normal structures

  11. Highly Efficient Training, Refinement, and Validation of a Knowledge-based Planning Quality-Control System for Radiation Therapy Clinical Trials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nan; Carmona, Ruben [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Sirak, Igor; Kasaova, Linda [Department of Oncology and Radiotherapy, University Hospital, Hradec Kralove (Czech Republic); Followill, David [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Michalski, Jeff; Bosch, Walter; Straube, William [Department of Radiation Oncology, Washington University in St Louis, St Louis, Missouri (United States); Mell, Loren K. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Moore, Kevin L., E-mail: kevinmoore@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States)

    2017-01-01

    Purpose: To demonstrate an efficient method for training and validation of a knowledge-based planning (KBP) system as a radiation therapy clinical trial plan quality-control system. Methods and Materials: We analyzed 86 patients with stage IB through IVA cervical cancer treated with intensity modulated radiation therapy at 2 institutions according to the standards of the INTERTECC (International Evaluation of Radiotherapy Technology Effectiveness in Cervical Cancer, National Clinical Trials Network identifier: 01554397) protocol. The protocol used a planning target volume and 2 primary organs at risk: pelvic bone marrow (PBM) and bowel. Secondary organs at risk were rectum and bladder. Initial unfiltered dose-volume histogram (DVH) estimation models were trained using all 86 plans. Refined training sets were created by removing sub-optimal plans from the unfiltered sample, and DVH estimation models… and DVH estimation models were constructed by identifying 30 of 86 plans emphasizing PBM sparing (comparing protocol-specified dosimetric cutpoints V{sub 10} (percentage volume of PBM receiving at least 10 Gy dose) and V{sub 20} (percentage volume of PBM receiving at least 20 Gy dose) with unfiltered predictions) and another 30 of 86 plans emphasizing bowel sparing (comparing V{sub 40} (absolute volume of bowel receiving at least 40 Gy dose) and V{sub 45} (absolute volume of bowel receiving at least 45 Gy dose), 9 in common with the PBM set). To obtain deliverable KBP plans, refined models must inform patient-specific optimization objectives and/or priorities (an auto-planning “routine”). Four candidate routines emphasizing different tradeoffs were composed, and a script was developed to automatically re-plan multiple patients with each routine. After selection of the routine that best met protocol objectives in the 51-patient training sample (KBP{sub FINAL}), protocol-specific DVH metrics and normal tissue complication probability were compared for original

  12. Percutaneous radiation therapy of peyronie's disease with 137cesium

    International Nuclear Information System (INIS)

    Schreiber, B.; Rossbach, T.; Schmitt, G.; Essen Univ.

    1978-01-01

    From 1966 to 1977, 49 patients suffering from Peyronie's disease received percutaneous radiation treatment with 137 Cesium ( 137 Cs). Therapy results were followed up for a period of from 2 months to 11 years. The method of 137 Cs radiation is described and the results compared with other forms of therapy. Percutaneous radiation therapy with 137 Cs seems to be the preferred treatment of Peyronie's disease because of its few side effects, rapid effectiveness, and low cost. (orig.) [de

  13. Potential for heavy particle radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Raju, M.R.; Phillips, T.L.

    1977-03-01

    Radiation therapy remains one of the major forms of cancer treatment. When x rays are used in radiotherapy, there are large variations in radiation sensitivity among tumors because of the possible differences in the presence of hypoxic but viable tumor cells, differences in reoxygenation during treatment, differences in distribution of the tumor cells in their cell cycle, and differences in repair of sublethal damage. When high-LET particles are used, depending upon the LET distribution, these differences are reduced considerably. Because of these differences between x rays and high-LET particle effects, the high-LET particles may be more effective on tumor cells for a given effect on normal cells. Heavy particles have potential application in improving radiotherapy because of improved dose localization and possible advantages of high-LET particles due to their radiobiological characteristics. Protons, because of their defined range, Bragg peak, and small effects of scattering, have good dose localization characteristics. The use of protons in radiotherapy minimizes the morbidity of radiotherapy treatment and is very effective in treating deep tumors located near vital structures. Fast neutrons have no physical advantages over /sup 60/Co gamma rays but, because of their high-LET component, could be very effective in treating tumors that are resistant to conventional radiations. Negative pions and heavy ions combine some of the advantages of protons and fast neutrons.

  14. Potential for heavy particle radiation therapy

    International Nuclear Information System (INIS)

    Raju, M.R.; Phillips, T.L.

    1977-03-01

    Radiation therapy remains one of the major forms of cancer treatment. When x rays are used in radiotherapy, there are large variations in radiation sensitivity among tumors because of the possible differences in the presence of hypoxic but viable tumor cells, differences in reoxygenation during treatment, differences in distribution of the tumor cells in their cell cycle, and differences in repair of sublethal damage. When high-LET particles are used, depending upon the LET distribution, these differences are reduced considerably. Because of these differences between x rays and high-LET particle effects, the high-LET particles may be more effective on tumor cells for a given effect on normal cells. Heavy particles have potential application in improving radiotherapy because of improved dose localization and possible advantages of high-LET particles due to their radiobiological characteristics. Protons, because of their defined range, Bragg peak, and small effects of scattering, have good dose localization characteristics. The use of protons in radiotherapy minimizes the morbidity of radiotherapy treatment and is very effective in treating deep tumors located near vital structures. Fast neutrons have no physical advantages over 60 Co gamma rays but, because of their high-LET component, could be very effective in treating tumors that are resistant to conventional radiations. Negative pions and heavy ions combine some of the advantages of protons and fast neutrons

  15. Radiation therapy for advanced gastric cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kosaka, Takeo; Sejima, Teruhiro; Sugaya, Jun-ichi [Kanazawa Medical Univ. (Japan)] [and others

    1997-09-01

    Thirteen patients with advanced gastric cancer treated by palliative radiotherapy were retrospectively analyzed. The radiation sites were abdominal cavities in 8 cases, superficial masses in 5 and lung metastasis in one. The purposes were to diminish mass size in 5 cases, to relieve pain in 3 and to reduce stenosis in 6. The total doses were more than 40 Gy in 10 patients. In 2 cases, the intracavitary irradiation was performed using {sup 192}Ir. In one case, radiation had to be stopped at the dose of 22.5 Gy because of poor general condition. Partial response was obtained in 6 of 12 cases (RP, 50%). The sites of responders were superficial lesions in 4 and hepatic hilar mass in 2, which were given intracavitary as well as external radiation. Pain relief was achieved in all patients suffering from it. One of 3 cases with esophageal stenosis showed marked improvement in swallowing. Two patients showed a decrease in the levels of tumor markers. Five patients had side effects of more than grade 2. Two of them were grade 3, one thrombocytopenia and one diarrhea. The median survival time of all cases was 9 months, and 5 patients could shift to home care. These results suggest that palliative radiotherapy could be one of the most useful locoregional therapies for advanced gastric cancer, in the aspect of improvement of patient`s QOL. (author)

  16. Radiation therapy for advanced gastric cancer

    International Nuclear Information System (INIS)

    Kosaka, Takeo; Sejima, Teruhiro; Sugaya, Jun-ichi

    1997-01-01

    Thirteen patients with advanced gastric cancer treated by palliative radiotherapy were retrospectively analyzed. The radiation sites were abdominal cavities in 8 cases, superficial masses in 5 and lung metastasis in one. The purposes were to diminish mass size in 5 cases, to relieve pain in 3 and to reduce stenosis in 6. The total doses were more than 40 Gy in 10 patients. In 2 cases, the intracavitary irradiation was performed using 192 Ir. In one case, radiation had to be stopped at the dose of 22.5 Gy because of poor general condition. Partial response was obtained in 6 of 12 cases (RP, 50%). The sites of responders were superficial lesions in 4 and hepatic hilar mass in 2, which were given intracavitary as well as external radiation. Pain relief was achieved in all patients suffering from it. One of 3 cases with esophageal stenosis showed marked improvement in swallowing. Two patients showed a decrease in the levels of tumor markers. Five patients had side effects of more than grade 2. Two of them were grade 3, one thrombocytopenia and one diarrhea. The median survival time of all cases was 9 months, and 5 patients could shift to home care. These results suggest that palliative radiotherapy could be one of the most useful locoregional therapies for advanced gastric cancer, in the aspect of improvement of patient's QOL. (author)

  17. Adjuvant radiation therapy in uterine carcinosarcoma: A population-based analysis of patient demographic and clinical characteristics, patterns of care and outcomes.

    Science.gov (United States)

    Manzerova, Julia; Sison, Cristina P; Gupta, Divya; Holcomb, Kevin; Caputo, Thomas A; Parashar, Bhupesh; Nori, Dattatreyudu; Wernicke, A Gabriella

    2016-05-01

    To examine clinical and demographic characteristics of a population-based cohort of patients with uterine carcinosarcoma (UCS), to assess access to treatment and survival patterns. Surveillance, Epidemiology and End Results database was queried for patients diagnosed in 1999-2010 and treated with surgery with or without adjuvant radiation therapy (aRT). The Kaplan-Meier method was used to estimate survival functions, and Cox proportional hazards regression - to analyze the effect of covariates on survival. 2342 patients were eligible. African Americans presented with more advanced AJCC stages than other races (35.4% vs. 29.1%; pAfrican Americans vs. others, and women diagnosed in 1999-2004 vs. in 2005-2010, received aRT at a similar rate: 36.5% vs. 39.9% (p=NS), and 39.5% vs. 38.9% (p=NS), respectively. There was a trend towards higher aRT utilization among patients younger than 65 vs. older (41.4% vs. 37.5%; paRT group: 42 vs. 22 (paRT group. African Americans were more likely to present with later stage disease and die of UCS than non-African Americans. Age and stage, but not race, influenced receipt of aRT. Patients treated more recently survived longer. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Evaluation of an atlas-based automatic segmentation software for the delineation of brain organs at risk in a radiation therapy clinical context

    International Nuclear Information System (INIS)

    Isambert, Aurelie; Dhermain, Frederic; Bidault, Francois; Commowick, Olivier; Bondiau, Pierre-Yves; Malandain, Gregoire; Lefkopoulos, Dimitri

    2008-01-01

    Background and purpose: Conformal radiation therapy techniques require the delineation of volumes of interest, a time-consuming and operator-dependent task. In this work, we aimed to evaluate the potential interest of an atlas-based automatic segmentation software (ABAS) of brain organs at risk (OAR), when used under our clinical conditions. Materials and methods: Automatic and manual segmentations of the eyes, optic nerves, optic chiasm, pituitary gland, brain stem and cerebellum of 11 patients on T1-weighted magnetic resonance, 3-mm thick slice images were compared using the Dice similarity coefficient (DSC). The sensitivity and specificity of the ABAS were also computed and analysed from a radiotherapy point of view by splitting the ROC (Receiver Operating Characteristic) space into four sub-regions. Results: Automatic segmentation of OAR was achieved in 7-8 min. Excellent agreement was obtained between automatic and manual delineations for organs exceeding 7 cm 3 : the DSC was greater than 0.8. For smaller structures, the DSC was lower than 0.41. Conclusions: These tests demonstrated that this ABAS is a robust and reliable tool for automatic delineation of large structures under clinical conditions in our daily practice, even though the small structures must continue to be delineated manually by an expert

  19. SU-E-P-58: Dosimetric Study of Conventional Intensity-Modulated Radiotherapy and Knowledge-Based Radiation Therapy for Postoperation of Cervix Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ma, C; Yin, Y [Shandong Tumor Hospital, Jinan, Shandong Provice (China)

    2015-06-15

    Purpose: To compare the dosimetric difference of the target volume and organs at risk(OARs) between conventional intensity-modulated radiotherapy(C-IMRT) and knowledge-based radiation therapy (KBRT) plans for cervix cancer. Methods: 39 patients with cervical cancer after surgery were randomly selected, 20 patient plans were used to create the model, the other 19 cases used for comparative evaluation. All plans were designed in Eclipse system. The prescription dose was 30.6Gy, 17 fractions, OARs dose satisfied to the clinical requirement. A paired t test was used to evaluate the differences of dose-volume histograms (DVH). Results: Comparaed to C-IMRT plan, the KBRT plan target can achieve the similar target dose coverage, D98,D95,D2,HI and CI had no difference (P≥0.05). The dose of rectum, bladder and femoral heads had no significant differences(P≥0.05). The time was used to design treatment plan was significant reduced. Conclusion: This study shows that postoperative radiotherapy of cervical KBRT plans can achieve the similar target and OARs dose, but the shorter designing time.

  20. Modern radiation therapy for extranodal lymphomas

    DEFF Research Database (Denmark)

    Yahalom, Joachim; Illidge, Tim; Specht, Lena

    2015-01-01

    , involving any organ in the body and the spectrum of histological sub-types, poses a challenge both for routine clinical care and for the conduct of prospective and retrospective studies. This has led to uncertainty and lack of consistency in RT approaches between centers and clinicians. Thus far...... adopted RT volume definitions based on the International Commission on Radiation Units and Measurements (ICRU), as has been widely adopted by the field of radiation oncology for solid tumors. Organ-specific recommendations take into account histological subtype, anatomy, the treatment intent, and other...

  1. Delayed damage after radiation therapy for head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Yoshiyuki [Osaka Dental Univ., Hirakata (Japan)

    2000-03-01

    I investigated radiation damage, including osteoradionecrosis, arising from tooth extraction in fields that had received radiation therapy for head and neck cancer, and evaluated the effectiveness of pilocarpine for xerostomia. Between January 1990 and April 1996, I examined 30 patients for bone changes after tooth extraction in fields irradiated at the Department of Oral Radiology, Osaka Dental University Hospital. Nineteen of the patients had been treated for nasopharyngeal cancer and 11 for oropharyngeal cancer. Between January and April 1996, 4 additional patients were given pilocarpine hydrochloride (3-mg, 6-mg and 9-mg of KSS-694 orally three times a day) for 12 weeks and evaluated every 4 weeks as a base line. One had been treated for nasopharyngeal carcinoma, two for cancer of the cheek and one for an unknown carcinoma. Eighteen of the patients (11 with nasopharyngeal carcinoma and 7 with oropharyngeal carcinoma) had extractions. Use of preoperative and postoperative radiographs indicated that damage to the bone following tooth extraction after radiation exposure was related to whether antibiotics were administered the day before the extraction, whether forceps or elevators were used, and whether the tooth was in the field of radiation. Xerostomia improved in all 4 of the patients who received 6-mg or 9-mg of pilocarpine. It improved saliva production and relieved the symptoms of xerostomia after radiation therapy for head and neck cancer, although there were minor side effects such as fever. This information can be used to improve the oral environment of patients who have received radiation therapy for head and neck cancer, and to better understand their oral environment. (author)

  2. Delayed damage after radiation therapy for head and neck cancer

    International Nuclear Information System (INIS)

    Matsumoto, Yoshiyuki

    2000-01-01

    I investigated radiation damage, including osteoradionecrosis, arising from tooth extraction in fields that had received radiation therapy for head and neck cancer, and evaluated the effectiveness of pilocarpine for xerostomia. Between January 1990 and April 1996, I examined 30 patients for bone changes after tooth extraction in fields irradiated at the Department of Oral Radiology, Osaka Dental University Hospital. Nineteen of the patients had been treated for nasopharyngeal cancer and 11 for oropharyngeal cancer. Between January and April 1996, 4 additional patients were given pilocarpine hydrochloride (3-mg, 6-mg and 9-mg of KSS-694 orally three times a day) for 12 weeks and evaluated every 4 weeks as a base line. One had been treated for nasopharyngeal carcinoma, two for cancer of the cheek and one for an unknown carcinoma. Eighteen of the patients (11 with nasopharyngeal carcinoma and 7 with oropharyngeal carcinoma) had extractions. Use of preoperative and postoperative radiographs indicated that damage to the bone following tooth extraction after radiation exposure was related to whether antibiotics were administered the day before the extraction, whether forceps or elevators were used, and whether the tooth was in the field of radiation. Xerostomia improved in all 4 of the patients who received 6-mg or 9-mg of pilocarpine. It improved saliva production and relieved the symptoms of xerostomia after radiation therapy for head and neck cancer, although there were minor side effects such as fever. This information can be used to improve the oral environment of patients who have received radiation therapy for head and neck cancer, and to better understand their oral environment. (author)

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

    International Nuclear Information System (INIS)

    Orton, C; Borras, C; Carlson, D

    2014-01-01

    Mechanisms by which radiation kills cells and ways cell damage can be repaired will be reviewed. The radiobiological parameters of dose, fractionation, delivery time, dose rate, and LET will be discussed. The linear-quadratic model for cell survival for high and low dose rate treatments and the effect of repopulation will be presented and discussed. The rationale for various radiotherapy techniques such as conventional fractionation, hyperfractionation, hypofractionation, and low and high dose rate brachytherapy, including permanent implants, will be presented. The radiobiological principles underlying radiation protection guidelines and the different radiation dosimetry terms used in radiation biology and in radiation protection will be reviewed. Human data on radiation induced cancer, including increases in the risk of second cancers following radiation therapy, as well as data on radiation induced tissue reactions, such as cardiovascular effects, for follow up times up to 20–40 years, published by ICRP, NCRP and BEIR Committees, will be examined. The latest risk estimates per unit dose will be presented. Their adoption in recent radiation protection standards and guidelines and their impact on patient and workers safety in radiotherapy will be discussed. Biologically-guided radiotherapy (BGRT) provides a systematic method to derive prescription doses that integrate patient-specific information about tumor and normal tissue biology. Treatment individualization based on patient-specific biology requires the identification of biological objective functions to facilitate the design and comparison of competing treatment modalities. Biological objectives provide a more direct approach to plan optimization instead of relying solely on dose-based surrogates and can incorporate factors that alter radiation response, such as DNA repair, tumor hypoxia, and relative biological effectiveness. We review concepts motivating biological objectives and provide examples of how

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

    Energy Technology Data Exchange (ETDEWEB)

    Orton, C [Wayne State University, Grosse Pointe, MI (United States); Borras, C [Radiological Physics and Health Services, Washington, DC (United States); Carlson, D [Yale University School of Medicine, New Haven, CT (United States)

    2014-06-15

    Mechanisms by which radiation kills cells and ways cell damage can be repaired will be reviewed. The radiobiological parameters of dose, fractionation, delivery time, dose rate, and LET will be discussed. The linear-quadratic model for cell survival for high and low dose rate treatments and the effect of repopulation will be presented and discussed. The rationale for various radiotherapy techniques such as conventional fractionation, hyperfractionation, hypofractionation, and low and high dose rate brachytherapy, including permanent implants, will be presented. The radiobiological principles underlying radiation protection guidelines and the different radiation dosimetry terms used in radiation biology and in radiation protection will be reviewed. Human data on radiation induced cancer, including increases in the risk of second cancers following radiation therapy, as well as data on radiation induced tissue reactions, such as cardiovascular effects, for follow up times up to 20–40 years, published by ICRP, NCRP and BEIR Committees, will be examined. The latest risk estimates per unit dose will be presented. Their adoption in recent radiation protection standards and guidelines and their impact on patient and workers safety in radiotherapy will be discussed. Biologically-guided radiotherapy (BGRT) provides a systematic method to derive prescription doses that integrate patient-specific information about tumor and normal tissue biology. Treatment individualization based on patient-specific biology requires the identification of biological objective functions to facilitate the design and comparison of competing treatment modalities. Biological objectives provide a more direct approach to plan optimization instead of relying solely on dose-based surrogates and can incorporate factors that alter radiation response, such as DNA repair, tumor hypoxia, and relative biological effectiveness. We review concepts motivating biological objectives and provide examples of how

  5. Whole abdomen radiation therapy in ovarian cancers: a comparison between fixed beam and volumetric arc based intensity modulation

    International Nuclear Information System (INIS)

    Mahantshetty, Umesh; Shrivastava, Shyamkishore; Cozzi, Luca; Jamema, Swamidas; Engineer, Reena; Deshpande, Deepak; Sarin, Rajiv; Fogliata, Antonella; Nicolini, Giorgia; Clivio, Alessandro; Vanetti, Eugenio

    2010-01-01

    A study was performed to assess dosimetric characteristics of volumetric modulated arcs (RapidArc, RA) and fixed field intensity modulated therapy (IMRT) for Whole Abdomen Radiotherapy (WAR) after ovarian cancer. Plans for IMRT and RA were optimised for 5 patients prescribing 25 Gy to the whole abdomen (PTV-WAR) and 45 Gy to the pelvis and pelvic nodes (PTV-Pelvis) with Simultaneous Integrated Boost (SIB) technique. Plans were investigated for 6 MV (RA6, IMRT6) and 15 MV (RA15, IMRT15) photons. Objectives were: for both PTVs V 90% > 95%, for PTV-Pelvis: D max < 105%; for organs at risk, maximal sparing was required. The MU and delivery time measured treatment efficiency. Pre-treatment Quality assurance was scored with Gamma Agreement Index (GAI) with 3% and 3 mm thresholds. IMRT and RapidArc resulted comparable for target coverage. For PTV-WAR, V 90% was 99.8 ± 0.2% and 93.4 ± 7.3% for IMRT6 and IMRT15, and 98.4 ± 1.7 and 98.6 ± 0.9% for RA6 and RA15. Target coverage resulted improved for PTV-Pelvis. Dose homogeneity resulted slightly improved by RA (Uniformity was defined as U 5-95% = D 5% -D 95% /D mean ). U 5 - 95% for PTV-WAR was 0.34 ± 0.05 and 0.32 ± 0.06 (IMRT6 and IMRT15), 0.30 ± 0.03 and 0.26 ± 0.04 (RA6 and RA15); for PTV-Pelvis, it resulted equal to 0.1 for all techniques. For organs at risk, small differences were observed between the techniques. MU resulted 3130 ± 221 (IMRT6), 2841 ± 318 (IMRT15), 538 ± 29 (RA6), 635 ± 139 (RA15); the average measured treatment time was 18.0 ± 0.8 and 17.4 ± 2.2 minutes (IMRT6 and IMRT15) and 4.8 ± 0.2 (RA6 and RA15). GAI IMRT6 = 97.3 ± 2.6%, GAI IMRT15 = 94.4 ± 2.1%, GAI RA6 = 98.7 ± 1.0% and GAI RA15 = 95.7 ± 3.7%. RapidArc showed to be a solution to WAR treatments offering good dosimetric features with significant logistic improvements compared to IMRT

  6. Whole abdomen radiation therapy in ovarian cancers: a comparison between fixed beam and volumetric arc based intensity modulation

    Directory of Open Access Journals (Sweden)

    Clivio Alessandro

    2010-11-01

    Full Text Available Abstract Purpose A study was performed to assess dosimetric characteristics of volumetric modulated arcs (RapidArc, RA and fixed field intensity modulated therapy (IMRT for Whole Abdomen Radiotherapy (WAR after ovarian cancer. Methods and Materials Plans for IMRT and RA were optimised for 5 patients prescribing 25 Gy to the whole abdomen (PTV_WAR and 45 Gy to the pelvis and pelvic nodes (PTV_Pelvis with Simultaneous Integrated Boost (SIB technique. Plans were investigated for 6 MV (RA6, IMRT6 and 15 MV (RA15, IMRT15 photons. Objectives were: for both PTVs V90% > 95%, for PTV_Pelvis: Dmax Results IMRT and RapidArc resulted comparable for target coverage. For PTV_WAR, V90% was 99.8 ± 0.2% and 93.4 ± 7.3% for IMRT6 and IMRT15, and 98.4 ± 1.7 and 98.6 ± 0.9% for RA6 and RA15. Target coverage resulted improved for PTV_Pelvis. Dose homogeneity resulted slightly improved by RA (Uniformity was defined as U5-95% = D5%-D95%/Dmean. U5-95% for PTV_WAR was 0.34 ± 0.05 and 0.32 ± 0.06 (IMRT6 and IMRT15, 0.30 ± 0.03 and 0.26 ± 0.04 (RA6 and RA15; for PTV_Pelvis, it resulted equal to 0.1 for all techniques. For organs at risk, small differences were observed between the techniques. MU resulted 3130 ± 221 (IMRT6, 2841 ± 318 (IMRT15, 538 ± 29 (RA6, 635 ± 139 (RA15; the average measured treatment time was 18.0 ± 0.8 and 17.4 ± 2.2 minutes (IMRT6 and IMRT15 and 4.8 ± 0.2 (RA6 and RA15. GAIIMRT6 = 97.3 ± 2.6%, GAIIMRT15 = 94.4 ± 2.1%, GAIRA6 = 98.7 ± 1.0% and GAIRA15 = 95.7 ± 3.7%. Conclusion RapidArc showed to be a solution to WAR treatments offering good dosimetric features with significant logistic improvements compared to IMRT.

  7. Radiation therapy of psoriasis and parapsoriasis

    International Nuclear Information System (INIS)

    Wiskemann, A.

    1982-01-01

    Selective UV-Phototherapy with lambda 300-320 nm (SUP) as well as oral photochemotherapy with 8-methoxy-psoralen plus UVA-radiation (PUVA intern) are very effective in clearing the lesions of the generalized psoriasis and those of the chronic forms of parapsoriasis. Being treated with 4 suberythemal doses per week psoriasis patients are free or nearly free of symptoms after averagely 6.3 weeks of SUP-therapy or after 5.3 weeks of PUVA orally. The PUVA-therapy is mainly indicated in pustular, inverse and erythrodermic psoriasis as well as in parapsoriasis en plaques and variegata. In all other forms of psoriasis and in pityriasis lichenoides-chronica, we prefer the SUP-therapy because of less acute or chronic side effects, and because of its better practicability. X-rays are indicated in psoriais of nails, grenz-rays in superficial psoriatic lesions of the face, the armpits, the genitals and the anal region. (orig.) [de

  8. Deformable image registration in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Seung Jong; Kim, Si Yong [Dept. of Radiation Oncology, Virginia Commonwealth University, Richmond (United States)

    2017-06-15

    The number of imaging data sets has significantly increased during radiation treatment after introducing a diverse range of advanced techniques into the field of radiation oncology. As a consequence, there have been many studies proposing meaningful applications of imaging data set use. These applications commonly require a method to align the data sets at a reference. Deformable image registration (DIR) is a process which satisfies this requirement by locally registering image data sets into a reference image set. DIR identifies the spatial correspondence in order to minimize the differences between two or among multiple sets of images. This article describes clinical applications, validation, and algorithms of DIR techniques. Applications of DIR in radiation treatment include dose accumulation, mathematical modeling, automatic segmentation, and functional imaging. Validation methods discussed are based on anatomical landmarks, physical phantoms, digital phantoms, and per application purpose. DIR algorithms are also briefly reviewed with respect to two algorithmic components: similarity index and deformation models.

  9. Volumetric modulated arc therapy versus step-and-shoot intensity modulated radiation therapy in the treatment of large nerve perineural spread to the skull base: a comparative dosimetric planning study

    Energy Technology Data Exchange (ETDEWEB)

    Gorayski, Peter; Fitzgerald, Rhys; Barry, Tamara [Department of Radiation Oncology, Princess Alexandra Hospital, Woolloongabba, Queensland (Australia); Burmeister, Elizabeth [Nursing Practice Development Unit, Princess Alexandra Hospital and Research Centre for Clinical and Community Practice Innovation, Griffith University, Brisbane, Queensland (Australia); Foote, Matthew [Department of Radiation Oncology, Princess Alexandra Hospital, Woolloongabba, Queensland (Australia); Diamantina Institute, University of Queensland, Brisbane, Queensland (Australia)

    2014-06-15

    Cutaneous squamous cell carcinoma with large nerve perineural (LNPN) infiltration of the base of skull is a radiotherapeutic challenge given the complex target volumes to nearby organs at risk (OAR). A comparative planning study was undertaken to evaluate dosimetric differences between volumetric modulated arc therapy (VMAT) versus intensity modulated radiation therapy (IMRT) in the treatment of LNPN. Five consecutive patients previously treated with IMRT for LNPN were selected. VMAT plans were generated for each case using the same planning target volumes (PTV), dose prescriptions and OAR constraints as IMRT. Comparative parameters used to assess target volume coverage, conformity and homogeneity included V95 of the PTV (volume encompassed by the 95% isodose), conformity index (CI) and homogeneity index (HI). In addition, OAR maximum point doses, V20, V30, non-target tissue (NTT) point max doses, NTT volume above reference dose, monitor units (MU) were compared. IMRT and VMAT plans generated were comparable for CI (P = 0.12) and HI (P = 0.89). VMAT plans achieved better V95 (P = < 0.001) and reduced V20 and V30 by 652 cubic centimetres (cc) (28.5%) and 425.7 cc (29.1%), respectively. VMAT increased MU delivered by 18% without a corresponding increase in NTT dose. Compared with IMRT plans for LNPN, VMAT achieved comparable HI and CI.

  10. Cost evaluation to optimise radiation therapy implementation in different income settings: A time-driven activity-based analysis.

    Science.gov (United States)

    Van Dyk, Jacob; Zubizarreta, Eduardo; Lievens, Yolande

    2017-11-01

    With increasing recognition of growing cancer incidence globally, efficient means of expanding radiotherapy capacity is imperative, and understanding the factors impacting human and financial needs is valuable. A time-driven activity-based costing analysis was performed, using a base case of 2-machine departments, with defined cost inputs and operating parameters. Four income groups were analysed, ranging from low to high income. Scenario analyses included department size, operating hours, fractionation, treatment complexity, efficiency, and centralised versus decentralised care. The base case cost/course is US$5,368 in HICs, US$2,028 in LICs; the annual operating cost is US$4,595,000 and US$1,736,000, respectively. Economies of scale show cost/course decreasing with increasing department size, mainly related to the equipment cost and most prominent up to 3 linacs. The cost in HICs is two or three times as high as in U-MICs or LICs, respectively. Decreasing operating hours below 8h/day has a dramatic impact on the cost/course. IMRT increases the cost/course by 22%. Centralising preparatory activities has a moderate impact on the costs. The results indicate trends that are useful for optimising local and regional circumstances. This methodology can provide input into a uniform and accepted approach to evaluating the cost of radiotherapy. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  11. SU-F-T-258: Efficacy of Exit Fluence-Based Dose Calculation for Prostate Radiation Therapy

    International Nuclear Information System (INIS)

    Siebers, J; Gardner, J; Neal, B

    2016-01-01

    Purpose: To investigate the efficacy of exit-fluence-based dose computation for prostate radiotherapy by determining if it estimates true dose more accurately than the original planning dose. Methods: Virtual exit-fluencebased dose computation was performed for 19 patients, each with 9–12 repeat CT images. For each patient, a 78 Gy treatment plan was created utilizing 5 mm CTV-to-PTV and OAR-to-PRV margins. A Monte Carlo framework was used to compute dose and exit-fluence images for the planning image and for each repeat CT image based on boney-anatomyaligned and prostate-centroid-aligned CTs. Identical source particles were used for the MC dose-computations on the planning and repeat CTs to maximize correlation. The exit-fluence-based dose and image were computed by multiplying source particle weights by FC(x,y)=FP(x,y)/FT(x,y), where (x,y) are the source particle coordinates projected to the exit-fluence plane and we denote the dose/fluence from the plan by (DP,FP), from the repeat-CT as (DT,FT), and the exit-fluence computation by (DFC,FFC). DFC mimics exit-fluence backprojection through the planning image as FT=FFC. Dose estimates were intercompared to judge the efficacy of exit-fluence-based dose computation. Results: Boney- and prostate-centroid aligned results are combined as there is no statistical difference between them, yielding 420 dose comparisons per dose-volume metric. DFC is more accurate than DP for 46%, 33%, and 44% of cases in estimating CTV D98, D50, and D2 respectively. DFC improved rectum D50 and D2 estimates 54% and 49% respectively and bladder D50 and D2 47 and 49% respectively. While averaged over all patients and images DFC and DP were within 3.1% of DT, they differed from DT by as much as 22% for GTV D98, 71% for the Bladder D50, 17% for Bladder D2, 19% for Rectum D2. Conclusion: Exit-fluence based dose computations infrequently improve CTV or OAR dose estimates and should be used with caution. Research supported in part by Varian

  12. Analysis of Vision Loss Caused by Radiation-Induced Optic Neuropathy After Particle Therapy for Head-and-Neck and Skull-Base Tumors Adjacent to Optic Nerves

    International Nuclear Information System (INIS)

    Demizu, Yusuke; Murakami, Masao; Miyawaki, Daisuke; Niwa, Yasue; Akagi, Takashi; Sasaki, Ryohei; Terashima, Kazuki; Suga, Daisaku; Kamae, Isao; Hishikawa, Yoshio

    2009-01-01

    Purpose: To assess the incident rates of vision loss (VL; based on counting fingers or more severe) caused by radiation-induced optic neuropathy (RION) after particle therapy for tumors adjacent to optic nerves (ONs), and to evaluate factors that may contribute to VL. Methods and Materials: From August 2001 to August 2006, 104 patients with head-and-neck or skull-base tumors adjacent to ONs were treated with carbon ion or proton radiotherapy. Among them, 145 ONs of 75 patients were irradiated and followed for greater than 12 months. The incident rate of VL and the prognostic factors for occurrence of VL were evaluated. The late effects of carbon ion and proton beams were compared on the basis of a biologically effective dose at α/β = 3 gray equivalent (GyE 3 ). Results: Eight patients (11%) experienced VL resulting from RION. The onset of VL ranged from 17 to 58 months. The median follow-up was 25 months. No significant difference was observed between the carbon ion and proton beam treatment groups. On univariate analysis, age (>60 years), diabetes mellitus, and maximum dose to the ON (>110 GyE 3 ) were significant, whereas on multivariate analysis only diabetes mellitus was found to be significant for VL. Conclusions: The time to the onset of VL was highly variable. There was no statistically significant difference between carbon ion and proton beam treatments over the follow-up period. Based on multivariate analysis, diabetes mellitus correlated with the occurrence of VL. A larger study with longer follow-up is warranted.

  13. Zero TE-based pseudo-CT image conversion in the head and its application in PET/MR attenuation correction and MR-guided radiation therapy planning.

    Science.gov (United States)

    Wiesinger, Florian; Bylund, Mikael; Yang, Jaewon; Kaushik, Sandeep; Shanbhag, Dattesh; Ahn, Sangtae; Jonsson, Joakim H; Lundman, Josef A; Hope, Thomas; Nyholm, Tufve; Larson, Peder; Cozzini, Cristina

    2018-02-18

    To describe a method for converting Zero TE (ZTE) MR images into X-ray attenuation information in the form of pseudo-CT images and demonstrate its performance for (1) attenuation correction (AC) in PET/MR and (2) dose planning in MR-guided radiation therapy planning (RTP). Proton density-weighted ZTE images were acquired as input for MR-based pseudo-CT conversion, providing (1) efficient capture of short-lived bone signals, (2) flat soft-tissue contrast, and (3) fast and robust 3D MR imaging. After bias correction and normalization, the images were segmented into bone, soft-tissue, and air by means of thresholding and morphological refinements. Fixed Hounsfield replacement values were assigned for air (-1000 HU) and soft-tissue (+42 HU), whereas continuous linear mapping was used for bone. The obtained ZTE-derived pseudo-CT images accurately resembled the true CT images (i.e., Dice coefficient for bone overlap of 0.73 ± 0.08 and mean absolute error of 123 ± 25 HU evaluated over the whole head, including errors from residual registration mismatches in the neck and mouth regions). The linear bone mapping accounted for bone density variations. Averaged across five patients, ZTE-based AC demonstrated a PET error of -0.04 ± 1.68% relative to CT-based AC. Similarly, for RTP assessed in eight patients, the absolute dose difference over the target volume was found to be 0.23 ± 0.42%. The described method enables MR to pseudo-CT image conversion for the head in an accurate, robust, and fast manner without relying on anatomical prior knowledge. Potential applications include PET/MR-AC, and MR-guided RTP. © 2018 International Society for Magnetic Resonance in Medicine.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Clayton B. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Thompson, Holly M. [Department of Diagnostic Radiology, University of California Davis Medical Center, Sacramento, California (United States); Benedict, Stanley H. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Seibert, J. Anthony [Department of Diagnostic Radiology, University of California Davis Medical Center, Sacramento, California (United States); Wong, Kenneth [Department of Radiation Oncology, University of California Los Angeles Jonsson Comprehensive Cancer Center, University of California David Geffen School of Medicine, Los Angeles, California (United States); Vaughan, Andrew T. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Chen, Allen M., E-mail: allenmchen@yahoo.com [Department of Radiation Oncology, University of California Los Angeles Jonsson Comprehensive Cancer Center, University of California David Geffen School of Medicine, Los Angeles, California (United States)

    2016-04-01

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

  15. Application of the measurement-based Monte Carlo method in nasopharyngeal cancer patients for intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Yeh, C.Y.; Lee, C.C.; Chao, T.C.; Lin, M.H.; Lai, P.A.; Liu, F.H.; Tung, C.J.

    2014-01-01

    This study aims to utilize a measurement-based Monte Carlo (MBMC) method to evaluate the accuracy of dose distributions calculated using the Eclipse radiotherapy treatment planning system (TPS) based on the anisotropic analytical algorithm. Dose distributions were calculated for the nasopharyngeal carcinoma (NPC) patients treated with the intensity modulated radiotherapy (IMRT). Ten NPC IMRT plans were evaluated by comparing their dose distributions with those obtained from the in-house MBMC programs for the same CT images and beam geometry. To reconstruct the fluence distribution of the IMRT field, an efficiency map was obtained by dividing the energy fluence of the intensity modulated field by that of the open field, both acquired from an aS1000 electronic portal imaging device. The integrated image of the non-gated mode was used to acquire the full dose distribution delivered during the IMRT treatment. This efficiency map redistributed the particle weightings of the open field phase-space file for IMRT applications. Dose differences were observed in the tumor and air cavity boundary. The mean difference between MBMC and TPS in terms of the planning target volume coverage was 0.6% (range: 0.0–2.3%). The mean difference for the conformity index was 0.01 (range: 0.0–0.01). In conclusion, the MBMC method serves as an independent IMRT dose verification tool in a clinical setting. - Highlights: ► The patient-based Monte Carlo method serves as a reference standard to verify IMRT doses. ► 3D Dose distributions for NPC patients have been verified by the Monte Carlo method. ► Doses predicted by the Monte Carlo method matched closely with those by the TPS. ► The Monte Carlo method predicted a higher mean dose to the middle ears than the TPS. ► Critical organ doses should be confirmed to avoid overdose to normal organs

  16. Radiation therapy in extrahepatic bile duct carcinoma

    International Nuclear Information System (INIS)

    Mahe, Marc; Romestaing, Pascale; Talon, Bernard; Ardiet, J.M.; Salerno, Nathalie; Sentenac, Irenee; Gerard, J.P.

    1991-01-01

    Fifty-one patients with carcinoma of the extrahepatic bile ducts (EHBD) received radiation therapy between Jan 1980-Dec 1988. The location of the tumors was: proximal third, 20 patients; middle third, 23; distal third, 3; diffuse, 5 patients. Thirty-six patients underwent surgery with complete gross resection in 14 (10/14 with positive margins), incomplete gross resection in 12 and only biopsy in 10. Fifteen patients had only biliary drainage without laparotomy after cytologic diagnosis of malignancy in 11/15. Radiation therapy was done with curative intent after complete or incomplete resection (n=26) and it was palliative in patients who had no resection or only biliary drainage (n=25). Twenty-five patients received external radiation-therapy (ERT) alone to the tumor and lymph nodes (mean dose 45 Gy/2Gy per fraction for cure, 35 Gy/10 fractions for palliation), 8 patients had only iridium-192 ( 192 Ir) implant (50-60 Gy at a 1 cm radius for cure, 30 Gy for palliation), 17 patients had both ERT + 192 Ir(ERT 42.5 Gy + 192 Ir 10-15 Gy for cure; ERT 20 Gy/5 fractions + 192 Ir 20-30 Gy for palliation) and one intra-operative irradiation + ERT. The overall survival rate for the entire group was 55, 28.5 and 15 percent at 12, 24, 36 months and median survival 12 months. Median survival was 22 months in patients treated with curative intent and only 10 months after palliative treatment (p0.03). Among patients who had curative treatment, median survival was 27.5 months after complete gross resection and 13 months after incomplete gross resection (p0.045). After complete gross resection 5/14 patients were alive without evolutive disease at 11, 19, 20, 23 and 41 months, 2 were alive with metastases at 25 and 27 months and 7/14 died of cancer from 7 to 59 months. The rate of complications was low: 3 cholangitis responsive to antibiotics, 1 hemobilia and 2 gastric ulcers. These results are encouraging especially for patients with complete gross resection but they must be

  17. Megavoltage X-Ray Imaging Based on Cerenkov Effect: A New Application of Optical Fibres to Radiation Therapy

    Directory of Open Access Journals (Sweden)

    A. Teymurazyan

    2012-01-01

    Full Text Available A Monte Carlo simulation was used to study imaging and dosimetric characteristics of a novel design of megavoltage (MV X-ray detectors for radiotherapy applications. The new design uses Cerenkov effect to convert X-ray energy absorbed in optical fibres into light for MV X-ray imaging. The proposed detector consists of a matrix of optical fibres aligned with the incident X rays and coupled to an active matrix flat-panel imager (AMFPI for image readout. Properties, such as modulation transfer function, detection quantum efficiency (DQE, and energy response of the detector, were investigated. It has been shown that the proposed detector can have a zero-frequency DQE more than an order of magnitude higher than that of current electronic portal imaging device (EPID systems and yet a spatial resolution comparable to that of video-based EPIDs. The proposed detector is also less sensitive to scattered X rays from patients than current EPIDs.

  18. SU-E-J-16: Automatic Image Contrast Enhancement Based On Automatic Parameter Optimization for Radiation Therapy Setup Verification

    International Nuclear Information System (INIS)

    Qiu, J; Li, H. Harlod; Zhang, T; Yang, D; Ma, F

    2015-01-01

    Purpose: In RT patient setup 2D images, tissues often cannot be seen well due to the lack of image contrast. Contrast enhancement features provided by image reviewing software, e.g. Mosaiq and ARIA, require manual selection of the image processing filters and parameters thus inefficient and cannot be automated. In this work, we developed a novel method to automatically enhance the 2D RT image contrast to allow automatic verification of patient daily setups as a prerequisite step of automatic patient safety assurance. Methods: The new method is based on contrast limited adaptive histogram equalization (CLAHE) and high-pass filtering algorithms. The most important innovation is to automatically select the optimal parameters by optimizing the image contrast. The image processing procedure includes the following steps: 1) background and noise removal, 2) hi-pass filtering by subtracting the Gaussian smoothed Result, and 3) histogram equalization using CLAHE algorithm. Three parameters were determined through an iterative optimization which was based on the interior-point constrained optimization algorithm: the Gaussian smoothing weighting factor, the CLAHE algorithm block size and clip limiting parameters. The goal of the optimization is to maximize the entropy of the processed Result. Results: A total 42 RT images were processed. The results were visually evaluated by RT physicians and physicists. About 48% of the images processed by the new method were ranked as excellent. In comparison, only 29% and 18% of the images processed by the basic CLAHE algorithm and by the basic window level adjustment process, were ranked as excellent. Conclusion: This new image contrast enhancement method is robust and automatic, and is able to significantly outperform the basic CLAHE algorithm and the manual window-level adjustment process that are currently used in clinical 2D image review software tools

  19. iMagis 2.0: a platform toward image-based processes inherent to radiation therapy

    International Nuclear Information System (INIS)

    Daudinot Lopez, M.; Miller Clemente, R.; Gonce Hernandez, E.

    2015-01-01

    Radiotherapy is one of the main weapons against the leading cause of death in Cuba. The integration between radiotherapy and imaging modalities show an increasing trend across clinical applications, innovation and research. The availability of a platform for the inclusion of new applications in this area is crucial. the goal of this work was to demonstrate the possibilities of iMagis 2.0 as an existing platform, with applications in the planning process of pre-treatment based on images of cancer patients. iMagis® was the first Cuban PACS DICOM support, and the most widely applied in the Cuban Health System. Some available plugins were applied for medical planning of simulated patients with a homemade flatbed prototype, the latter installed on a CT unit SHIMADZU SCT 7800 TC in an Oncology Center. Multiple views for definitions of treatment volume were used, including the two-dimensional multiplanar reconstructions visualization. the viability of basic operations such as zoom images, rotations and translations are demonstrated. Monitoring changes in tumor volume during treatment were shown in combination with the estimated statistics of regions of interest. iMagis® supports a wide range of imaging modalities: computed Tomography, Magnetic Imaging PET / CT scan, Ultrasound, angiography, SPECT and providing a ready platform for adding new feature for radiotherapy and diagnostic. (Author)

  20. Effect of body mass index on shifts in ultrasound-based image-guided intensity-modulated radiation therapy for abdominal malignancies

    International Nuclear Information System (INIS)

    Choi, Mehee; Fuller, Clifton D.; Wang, Samuel J.; Siddiqi, Ather; Wong, Adrian; Thomas, Charles R.; Fuss, Martin

    2009-01-01

    Background and purpose: We investigated whether corrective shifts determined by daily ultrasound-based image-guidance correlate with body mass index (BMI) of patients treated with image-guided intensity-modulated radiation therapy (IG-IMRT) for abdominal malignancies. The utility of daily image-guidance, particularly for patients with BMI > 25.0, is examined. Materials and methods: Total 3162 ultrasound-directed shifts were performed in 86 patients. Direction and magnitude of shifts were correlated with pretreatment BMI. Bivariate statistical analysis and analysis of set-up correction data were performed using systematic and random error calculations. Results: Total 2040 daily alignments were performed. Average 3D vector of set-up correction for all patients was 12.1 mm/fraction. Directional and absolute shifts and 3D vector length were significantly different between BMI cohorts. 3D displacement averaged 4.9 mm/fraction and 6.8mm/fraction for BMI ≤ 25.0 and BMI > 25.0, respectively. Systematic error in all axes and 3D vector was significantly greater for BMI > 25.0. Differences in random error were not statistically significant. Conclusions: Set-up corrections derived from daily ultrasound-based IG-IMRT of abdominal tumors correlated with BMI. Daily image-guidance may improve precision of IMRT delivery with benefits assessed for the entire population, particularly patients with increased habitus. Requisite PTV margins suggested in the absence of daily image-guidance are significantly greater in patients with BMI > 25.0.

  1. Method of radiation therapy treatment planning

    International Nuclear Information System (INIS)

    Hodes, L.

    1976-01-01

    A technique of radiation therapy treatment planning designed to allow the assignment of dosage limits directly to chosen points in the computer-displayed cross-section of the patient. These dosage limits are used as constraints in a linear programming attempt to solve for beam strengths, minimizing integral dosage. If a feasible plan exists, the optimized plan will be displayed for approval as an isodose pattern. If there is no feasible plan, the operator/therapist can designate some of the point dosage constraints as ''relaxed.'' Linear programming will then optimize for minimum deviation at the relaxed points. This process can be iterated and new points selected until an acceptable plan is realized. In this manner the plan is optimized for uniformity as well as overall low dosage. 6 claims, 6 drawing figures

  2. Radiation protection at hadron therapy facilities

    International Nuclear Information System (INIS)

    Pelliccioni, M.

    2011-01-01

    The Italian National Centre for Oncological Hadron-therapy is currently under construction in Pavia. It is designed for the treatment of deep-seated tumours (up to a depth of 27 cm of water equivalent) with proton and C-ion beams as well as for both clinical and radio-biological research. The particles will be accelerated by a 7-MeV u -1 LINAC injector and a 400-MeV u -1 synchrotron. In the first phase of the project, three treatment rooms will be in operation, equipped with four fixed beams, three horizontal and one vertical. The accelerators are currently undergoing commissioning. The main radiation protection problems encountered (shielding, activation, etc.) are hereby illustrated and discussed in relation to the constraints set by the Italian national authorities. (authors)

  3. Clinical results of radiation therapy for thymoma

    Energy Technology Data Exchange (ETDEWEB)

    Masunaga, Shin-ichiro; Ono, Koji; Hiraoka, Masahiro; Sasai, Keisuke; Kitakabu, Yoshizumi; Abe, Mitsuyuki (Kyoto Univ. (Japan). Faculty of Medicine); Takahashi, Masaji; Tsutsui, Kazushige; Fushiki, Masato

    1992-05-01

    From August 1968 to December 1989, 58 patients with thymoma were treated by radiotherapy using cobalt-60 gamma ray. Eleven cases were treated by radiothrapy alone, 1 by preoperative radiotheapy, 43 by postoperative radiotherapy, and 3 in combination with intraoperative radiotherapy. The following points were clarified: (a) Postoperative and intraoperative radiotherapy were effective; (b) For postoperative radiotherapy, operability was the major factor influencing survival and local control, and Stage I and II tumors resected totally or subtotally as well as Stage III tumors resected totally were good indications for such therapy; (c) The patients with complicating myasthenia gravis had a longer survival time and better local control rate than those without it. Radiation pneumonitis was observed in 17 patients, and none of them died of this complication. In all cases in combination with intraoperative radiotherapy, dry desquamation was observed within the irradiated field. (author).

  4. Radiation therapy for intrahepatic recurrence after hepatectomy for hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Otsuka, Masaaki; Ohara, Kiyosi; Takada, Yasutsugu; Ueda, Takanori; Murata, Souichirou; Ushijima, Ryou; Adachi, Shinya; Todoroki, Takesi

    2003-01-01

    The intrahepatic recurrence rate after curative hepatectomy for hepatocellular carcinoma (HCC) is high, and management of recurrence is thus important for long-term survival. The use of radiation therapy has been relatively uncommon in the treatment of recurrent HCC. Eight patients underwent radiation therapy for recurrent HCC 12-98 months after hepatectomy. Five of them were treated with protons (250 MeV; 68.8-84.5 Gy), and three were treated with X-rays (6 MV; 60 or 70 Gy). One patient received radiation therapy twice for another lesion with a 79-month interval. The target tumors were 1.2-4.5 cm. All patients also underwent transcatheter arterial embolization or other regional therapy. Although transient ascites was found in three patients after radiation therapy, no patient died as a result of the irradiation. Seven patients died 9 months to 4 years (median 1 year 6 months) after radiation therapy. Re-recurrence was observed in the irradiated liver in two patients (local control 78%). Four patients died of lung metastasis after radiation therapy. The median survival time was 3 years 3 months (range 1 year 1 month to 8 years 6 months) after recurrence. Multimodality therapy is necessary for the management of recurrence. Radiation therapy could be beneficial when other therapies present some difficulty regarding application or are performed incompletely. It must be emphasized that radiation therapy should be considered in addition to other regional therapies for the treatment of recurrent or re-recurrent HCC, and that radiation therapy can be repeated in selected patients. (author)

  5. Survival Outcomes of Whole-Pelvic Versus Prostate-Only Radiation Therapy for High-Risk Prostate Cancer Patients With Use of the National Cancer Data Base

    Energy Technology Data Exchange (ETDEWEB)

    Amini, Arya; Jones, Bernard L.; Yeh, Norman; Rusthoven, Chad G.; Armstrong, Hirotatsu; Kavanagh, Brian D., E-mail: brian.kavanagh@ucdenver.edu

    2015-12-01

    Purpose/Objectives: The addition of whole pelvic (WP) compared with prostate-only (PO) radiation therapy (RT) for clinically node-negative prostate cancer remains controversial. The purpose of our study was to evaluate the survival benefit of adding WPRT versus PO-RT for high-risk, node-negative prostate cancer, using the National Cancer Data Base (NCDB). Methods and Materials: Patients with high-risk prostate cancer treated from 2004 to 2006, with available data for RT volume, coded as prostate and pelvis (WPRT) or prostate alone (PO-RT) were included. Multivariate analysis (MVA) and propensity-score matched analysis (PSM) were performed. Recursive partitioning analysis (RPA) based on overall survival (OS) using Gleason score (GS), T stage, and pretreatment prostate-specific antigen (PSA) was also conducted. Results: A total of 14,817 patients were included: 7606 (51.3%) received WPRT, and 7211 (48.7%) received PO-RT. The median follow-up time was 81 months (range, 2-122 months). Under MVA, the addition of WPRT for high-risk patients had no OS benefit compared with PO-RT (HR 1.05; P=.100). On subset analysis, patients receiving dose-escalated RT also did not benefit from WPRT (HR 1.01; P=.908). PSM confirmed no survival benefit with the addition of WPRT for high-risk patients (HR 1.05; P=.141). In addition, RPA was unable to demonstrate a survival benefit of WPRT for any subset. Other prognostic factors for inferior OS under MVA included older age (HR 1.25; P<.001), increasing comorbidity scores (HR 1.46; P<.001), higher T stage (HR 1.17; P<.001), PSA (HR 1.81; P<.001), and GS (HR 1.29; P<.001), and decreasing median county household income (HR 1.15; P=.011). Factors improving OS included the addition of androgen deprivation therapy (HR 0.92; P=.033), combination external beam RT plus brachytherapy boost (HR 0.71; P<.001), and treatment at an academic/research institution (HR 0.84; P=.002). Conclusion: In the largest reported analysis of WPRT for patients with

  6. Radiation Therapy in Peru: Achievements and Challenges

    International Nuclear Information System (INIS)

    Guerrero, P.; Má, C.; Venegas, D.; Bustamante, R.

    2015-01-01

    Peru is the fastest growing economy in Latin America (sustained increase in GDP, low inflation and poverty reduction). The health system is fragmented and until 2012, almost half of the population had no health insurance. The current government poses: Improved access to health and education, employment and social security, reducing extreme poverty, within a context of social inclusion. The Plan for Prevention and Control of Cancer (“Plan Esperanza”) was established in 2012 in order to reduce cancer mortality and morbidity, with greater access to oncology services (promotion, prevention, early diagnosis, treatment and palliative care). With an area of 1 285 216 square kilometers and almost 30 million inhabitants, cancer treatment resources are scarce. Regarding Radiation Therapy, until 2007, it existed only in Lima, the capital city (over 9 million inhabitants). Later, another services were established in two more regions. At present, there is 23 radiotherapy machines in whole country. In this regard, Plan Esperanza is working on strengthening Radiation Therapy Services nationwide. Considering the population demand and availability of other cancer services (chemotherapy, oncologic surgery), the regions where need create new radiotherapy services were identified: 3 Hospitals in Lima (in peripheral areas: Cayetano Heredia at the North, Hipólito Unanue at East and Maria Auxiliadora at South). Also, other Regions of the country: Piura, Lambayeque, La Libertad at North; Junín in the Central Highland, Cusco in the Southern Highland, and Loreto in the Northern Forest. Each with 2 linear accelerators, except Loreto, where they will consider two 60 Cobalt bomb instead, due to the geographical conditions. Moreover, one linear accelerator in Arequipa Region will be acquired. In Lima, the Hospitals are projected to become operational in 2016, while in the Regions, the Ministry of Health is providing them technical assistance in needs identification, planning and

  7. Managing radiation therapy side effects with complementary medicine.

    Science.gov (United States)

    Thomas, Jerah; Beinhorn, Curtiss; Norton, Dena; Richardson, Michael; Sumler, Sat-Siri; Frenkel, Moshe

    2010-01-01

    Over one-third of Americans use complementary and alternative medicine (CAM). The prevalence among cancer patients may even be higher. Complementary therapies may reduce possible symptom burdens caused by conventional cancer treatments. Integrating CAM therapies has become more common and more accepted in clinical oncology. However, little research is available on beneficial CAM therapies for radiation therapy patients. This article reviews potential CAM therapies that have been shown to be effective in decreasing the symptom burden related to radiation therapy treatments and includes clinical observations from CAM practitioners in a comprehensive cancer center.

  8. Breast Cancer Biology: Clinical Implications for Breast Radiation Therapy.

    Science.gov (United States)

    Horton, Janet K; Jagsi, Reshma; Woodward, Wendy A; Ho, Alice

    2018-01-01

    Historically, prognosis and treatment decision making for breast cancer patients have been dictated by the anatomic extent of tumor spread. However, in recent years, "breast cancer" has proven to be a collection of unique phenotypes with distinct prognoses, patterns of failure, and treatment responses. Recent advances in biologically based assays and targeted therapies designed to exploit these unique phenotypes have profoundly altered systemic therapy practice patterns and treatment outcomes. Data associating locoregional outcomes with tumor biology are emerging. However, the likelihood of obtaining level I evidence for fundamental radiation therapy questions within each of the specific subtypes in the immediate future is low. As such, this review aims to summarize the existing data and provide practical context for the incorporation of breast tumor biology into clinical practice. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Urothelial cancers following radiation therapy for cervical cancer

    International Nuclear Information System (INIS)

    Nakata, Seiji; Hasumi, Masaru; Sato, Jin; Mayuzumi, Takuji; Kumasaka, Fuminari; Shimizu, Toshihiro.

    1996-01-01

    Some reports have indicated that bladder cancer is induced by radiation therapy for cervical cancer. We encountered 6 cases of urothelial cancer (5 cases of bladder cancer and 1 case of ureter cancer) following radiation therapy for cervical cancer. Age at the time of diagnosis of cervical cancer ranged from 38 to 66 years, and the average was 51.2±11.0 (S.D.) years old. Age at the time of diagnosis of urothelial cancer ranged from 53 to 83 years, and the average was 67.5±10.3 years old. The interval between the diagnosis of cervical cancer and urothelial cancer ranged from 3 to 25 years, averaging 16.3 years. It is impossible to evaluate the risk of development of urothelial cancer after radiation therapy based on our data. However, it is important to make an effort to diagnose urothelial cancer at an early stage by educating patients (e.g., advising regular urine tests) after the follow-up period to cervical cancer. (author)

  10. Stroke After Radiation Therapy for Head and Neck Cancer: What Is the Risk?

    International Nuclear Information System (INIS)

    Arthurs, Erin; Hanna, Timothy P.; Zaza, Khaled; Peng, Yingwei; Hall, Stephen F.

    2016-01-01

    Purpose: A retrospective population-based cohort study was conducted to determine the risk of ischemic stroke with respect to time, associated with curative radiation therapy in head and neck squamous cell carcinomas (HNSCC). Methods and Materials: On the basis of data from the Ontario Cancer Registry and regional cancer treatment centers, 14,069 patients were identified with diagnoses of squamous cell carcinoma of the oral cavity, larynx, and pharynx who were treated for cure between 1990 and 2010. Hazards of stroke and time to stroke were examined, accounting for the competing risk of death. Stroke risk factors identified through diagnostic and procedural administrative codes were adjusted for in the comparison between treatment regimens, which included surgery alone versus radiation therapy alone and surgery alone versus any exposure to radiation therapy. Results: Overall, 6% of patients experienced an ischemic stroke after treatment, with 5% experiencing a stroke after surgery, 8% after radiation therapy alone, and 6% after any exposure to radiation therapy. The cause-specific hazard ratios of ischemic stroke after radiation therapy alone and after any exposure to radiation therapy compared with surgery were 1.70 (95% confidence interval [CI]: 1.41-2.05) and 1.46 (95% CI: 1.23-1.73), respectively, after adjustment for stroke risk factors, patient factors, and disease-related factors. Conclusions: Radiation therapy was associated with an increased risk of ischemic stroke compared with surgery alone: for both radiation therapy alone and after all treatment modalities that included any radiation treatment were combined. Because of a shift toward a younger HNSCC patient population, our results speak to the need for adequate follow-up and survivorship care among patients who have been treated with radiation therapy. Advances in treatment that minimize chronic morbidity also require further evaluation.

  11. Stroke After Radiation Therapy for Head and Neck Cancer: What Is the Risk?

    Energy Technology Data Exchange (ETDEWEB)

    Arthurs, Erin [Department of Public Health Sciences, Queen' s University, Kingston, Ontario (Canada); Hanna, Timothy P. [Division of Cancer Care and Epidemiology, Queen' s University, Kingston, Ontario (Canada); Department of Oncology, Queen' s University, Kingston, Ontario (Canada); Zaza, Khaled [Department of Oncology, Queen' s University, Kingston, Ontario (Canada); Peng, Yingwei [Department of Public Health Sciences, Queen' s University, Kingston, Ontario (Canada); Hall, Stephen F., E-mail: sfh@queensu.ca [Division of Cancer Care and Epidemiology, Queen' s University, Kingston, Ontario (Canada); Department of Otolaryngology, Queen' s University, Kingston, Ontario (Canada)

    2016-11-01

    Purpose: A retrospective population-based cohort study was conducted to determine the risk of ischemic stroke with respect to time, associated with curative radiation therapy in head and neck squamous cell carcinomas (HNSCC). Methods and Materials: On the basis of data from the Ontario Cancer Registry and regional cancer treatment centers, 14,069 patients were identified with diagnoses of squamous cell carcinoma of the oral cavity, larynx, and pharynx who were treated for cure between 1990 and 2010. Hazards of stroke and time to stroke were examined, accounting for the competing risk of death. Stroke risk factors identified through diagnostic and procedural administrative codes were adjusted for in the comparison between treatment regimens, which included surgery alone versus radiation therapy alone and surgery alone versus any exposure to radiation therapy. Results: Overall, 6% of patients experienced an ischemic stroke after treatment, with 5% experiencing a stroke after surgery, 8% after radiation therapy alone, and 6% after any exposure to radiation therapy. The cause-specific hazard ratios of ischemic stroke after radiation therapy alone and after any exposure to radiation therapy compared with surgery were 1.70 (95% confidence interval [CI]: 1.41-2.05) and 1.46 (95% CI: 1.23-1.73), respectively, after adjustment for stroke risk factors, patient factors, and disease-related factors. Conclusions: Radiation therapy was associated with an increased risk of ischemic stroke compared with surgery alone: for both radiation therapy alone and after all treatment modalities that included any radiation treatment were combined. Because of a shift toward a younger HNSCC patient population, our results speak to the need for adequate follow-up and survivorship care among patients who have been treated with radiation therapy. Advances in treatment that minimize chronic morbidity also require further evaluation.

  12. Intraoperative validation of CT-based lymph nodal levels, sublevels IIa and IIb: Is it of clinical relevance in selective radiation therapy?

    International Nuclear Information System (INIS)

    Levendag, Peter; Gregoire, Vincent; Hamoir, Marc; Voet, Peter; Est, Henrie van der; Heijmen, Ben; Kerrebijn, Jeroen

    2005-01-01

    Purpose: The objectives of this study are to discuss the intraoperative validation of CT-based boundaries of lymph nodal levels in the neck, and in particular the clinical relevance of the delineation of sublevels IIa and IIb in case of selective radiation therapy (RT). Methods and Materials: To validate the radiologically defined level contours, clips were positioned intraoperatively at the level boundaries defined by surgical anatomy. In 10 consecutive patients, clips were placed, at the time of a neck dissection being performed, at the most cranial border of the neck. Anterior-posterior and lateral X-ray films were obtained intraoperatively. Next, in 3 patients, neck levels were contoured on preoperative contrast-enhanced CT scans according to the international consensus guidelines. From each of these 3 patients, an intraoperative CT scan was also obtained, with clips placed at the surgical-anatomy-based level boundaries. The preoperative (CT-based) and intraoperative (surgery-defined) CT scans were matched. Results: Clips placed at the most cranial part of the neck lined up at the caudal part of the transverse process of the cervical vertebra C-I. The posterior border of surgical level IIa (spinal accessory nerve [SAN]) did not match with the posterior border of CT-based level IIa (internal jugular vein [IJV]). Other surgical boundaries and CT-based contours were in good agreement. Conclusions: The cranial border of the neck, i.e., the cranial border of level IIa/IIb, corresponds to the caudal edge of the lateral process of C-I. Except for the posterior border between level IIa and level IIb, a perfect match was observed between the other surgical-clip-identified levels II-V boundaries (surgical-anatomy) and the CT-based delineation contours. It is argued that (1) because of the parotid gland overlapping part of level II, and (2) the frequent infestation of occult metastatic cells in the lymph channels around the IJV, the division of level II into radiologic

  13. Diagnostic imaging and radiation therapy equipment

    International Nuclear Information System (INIS)

    1990-05-01

    This is the third edition of CSA Standard C22.2 No. 114 (now CAN/CSA-C22.2 No. 114), which is one of a series of standards issued by the Canadian Standards Association under Part II of the Canadian Electrical Code. This edition marks an important shift towards harmonization of Canadian requirements with those of the European community and the United States. Also important to this edition is the expansion of its scope to include the complete range of diagnostic imaging and radiation therapy equipment, rather than solely radiation-emitting equipment. In so doing, equipment previously addressed by CSA Standard C22.2 No. 125, Electromedical Equipment, specifically lasers for medical applications and diagnostic ultrasound units, is now dealt with in the new edition. By virtue of this expanded scope, many of the technical requirements in the electromedical equipment standard have been introduced to the new edition, thereby bringing CSA Standard C22.2 No. 114 up to date. 14 tabs., 16 figs

  14. Coronary artery disease following mediastinal radiation therapy

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  15. Experimental frontiers in radiation therapy of cancer

    International Nuclear Information System (INIS)

    Kaplan, H.S.

    1979-01-01

    Eighty years of the history of radiation therapy are reviewed. Discovery of X-ray, radioactivity and radium was made at the end of the 19th Century. The products of nuclear fission reactions such as 60 Co and the high-energy beam generated by megavoltage devices are used as effective tools to ionize beneath the skin surface where cancerous change is present. Development of more selective devices was performed from both the irradiating means and chemically sensitive and selective sensitizers. Differential radioprotection is also a valid means to improve therapeutic gain. The radiosensitivity of mammalian cells is reduced approximately 3-fold when they are irradiated in nitrogen atmosphere rather than in air or in oxygen. As the differential modification of radiosensitivity currently used, the following means are practiced: (a) increased yield of irreversible radiation lesions, (b) increased intrinsic sensitivity of target DNA, (c) inhibition of repair, (d) optimization of dose fractionation schedules and (e) differential radioprotection of normal tumors. With 156 references up to 1978. (Yamashita, S.)

  16. Virtual reality in radiation therapy training.

    Science.gov (United States)

    Boejen, Annette; Grau, Cai

    2011-09-01

    Integration of virtual reality (VR) in clinical training programs is a novel tool in radiotherapy. This paper presents a review of the experience with VR and Immersive visualization in 3D perspective for planning and delivery of external radiotherapy. Planning and delivering radiation therapy is a complex process involving physicians, physicists, radiographers and radiation therapists/nurses (RTT's). The specialists must be able to understand spatial relationships in the patient anatomy. Although still in its infancy, VR tools have become available for radiotherapy training, enabling students to simulate and train clinical situations without interfering with the clinical workflow, and without the risk of making errors. Immersive tools like a 3D linear accelerator and 3D display of dose distributions have been integrated into training, together with IT-labs with clinical software. Training in a VR environment seems to be cost-effective for the clinic. Initial reports suggest that 3D display of dose distributions may improve treatment planning and decision making. Whether VR training qualifies the students better than conventional training is still unsettled, but the first results are encouraging. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Aesthetic results following partial mastectomy and radiation therapy

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  18. The Effect of Therapy Oriented CT in Radiation Therapy Planning

    International Nuclear Information System (INIS)

    Kim, Sung Kyu; Shin, Sei One; Kim, Myung Se

    1987-01-01

    The success of radiation therapy depends on exact treatment of the tumor with significant high dose for maximizing local control and excluding the normal tissues for minimizing unwanted complications. To achieve these goals, correct estimation of target volume in three dimension, exact dose distribution in tumor and normal critical structures and correction of tissue inhomogeneity are required. The effect of therapy oriented CT (planning CT) were compared with conventional simulation method in necessity of planning change, set dose, and proper distribution of tumor dose. Of 365 new patients examined, planning CT was performed in 104 patients (28%). Treatment planning was changed in 47% of head and neck tumor, 79% of intrathoracic tumor and 63% of abdominal tumor. In breast cancer and musculoskeletal tumors, planning CT was recommended for selection of adequate energy and calculation of exact dose to critical structures such as kidney or spinal cord. The average difference of tumor doses between CT planning and conventional simulation was 10% in intrathoracic and intra-abdominal tumors but 20% in head and neck tumors which suggested that tumor dose may be overestimated in conventional simulation. Although some limitations and disadvantages including the cost and irradiation during CT are still criticizing, our study showed that CT planning is very helpful in radiotherapy planning

  19. Physics fundamentals and biological effects of synchrotron radiation therapy

    International Nuclear Information System (INIS)

    Prezado, Y.

    2010-01-01

    The main goal of radiation therapy is to deposit a curative dose in the tumor without exceeding the tolerances in the nearby healthy tissues. For some radioresistant tumors, like gliomas, requiring high doses for complete sterilization, the major obstacle for curative treatment with ionizing radiation remains the limited tolerance of the surrounding healthy tissue. This limitation is particularly severe for brain tumors and, especially important in children, due to the high risk of complications in the development of the central nervous system. In addition, the treatment of tumors close to an organ at risk, like the spinal cord, is also restricted. One possible solution is the development of new radiation therapy techniques exploiting radically different irradiation modes and modifying, in this way, the biological equivalent doses. This is the case of synchrotron radiation therapy (SRT). In this work the three new radiation therapy techniques under development at the European Synchrotron Radiation Facility (ESRF), in Grenoble (France) will be described, namely: synchrotron stereotactic radiation therapy (SSRT), microbeam radiation therapy (MRT) and minibeam radiation therapy. The promising results in the treatment of the high grade brain tumors obtained in preclinical studies have paved the way to the clinical trials. The first patients are expected in the fall of 2010. (Author).

  20. Precise positioning of patients for radiation therapy

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  1. Radiation therapy for malignant lid tumor

    International Nuclear Information System (INIS)

    Totsuka, Seiichi; Itsuno, Hajime

    1991-01-01

    The case of a 42-year-old man with Meibomian gland carcinoma in his right lower lid is reported. The tumor found in the nasal part of the lower lid, was 12 mm x 13 mm in size. First, surgical resection was performed. The pathological diagnosis of the frozen section was 'undifferentiated basal cell epithelioma'. Second, cryotherapy was performed all over the cut surface. Later, the permanent section was pathologically diagnosed as 'undifferentiated Meibomian gland carcinoma'. Total 50 Gy irradiation therapy was therefore performed using a 9 Mev Linac electron beam, 25 x 20 mm field, with a lead protector for the cornea and lens. A lead contact lens did not afford good results because it was too easily shifted on the cornea, owing to its weight. Therefore, we made a racket-shaped lead protector. Fixed well with tape, this protector afforded good protective effect. Three years after treatment, the patient has good visual function, with no recurrence. This racket-shaped lead protector is thought to be useful in radiation therapy for malignant lid tumors. (author)

  2. Influence of radiation therapy on T-lymphocyte subpopulations

    International Nuclear Information System (INIS)

    Job, G.

    1984-01-01

    The author claims this to be the first time where monoclonal antibodies are used in a long-term study in order to determine the influence of radiation therapy on T-lymphozyte-subpopulations in patients suffering from malignant growths. The influence of radiation therapy on B-cells, T-cells and macrophages was also checked. Two groups of patients were given two different radiation doses, and examined separately in order to discover possible effects of the dosage. Radiation therapy reduced B- and T-lymphocytes to the same degree as the total lymphozyte population so that their shares in percent remained unchanged. The same was also found for macrophages. Determination of clones and suppressor T-lymphozytes before, during and after radiation showed T-lymphozytes to have a higher resistance against the influence of radiation than clones. Suppressor cells also regenerated more quickly than clones after the end of the therapy. While radiation therapy was applied the clone/suppressor cell ratio dropped to values lower than those of the healthy reference group. After the end of the therapy this quotient dropped even further in some cases while in others it began to rise slowly, but even 6 months after the end of the therapy it was still lower than normal. As a number of diseases show an increased 'immunoregulatory quotient' it would be conceivable to influence this quotient with radiation therapy in order to achieve a therapeutic effect. (orig./MG) [de

  3. Source book of educational materials for radiation therapy. Final report

    International Nuclear Information System (INIS)

    Pijar, M.L.

    1979-08-01

    The Source Book is a listing of educational materials in radiation therapy technology. The first 17 sections correspond to the subjects identified in the ASRT Curriculum Guide for schools of radiation therapy. Each section is divided into publications and in some sections audiovisuals and training aids. Entries are listed without endorsement

  4. The role of radiation therapy in bone metastases management

    OpenAIRE

    Felice, Francesca De; Piccioli, Andrea; Musio, Daniela; Tombolini, Vincenzo

    2017-01-01

    Bone metastases represent an important complication of malignant tumours. Despite improvement in surgical techniques and advances in systemic therapies, management of patients with bone metastatic disease remains a powerful cornerstone for the radiation oncologist. The primary goal of radiation therapy is to provide pain relief, preserving patients quality of life.

  5. Stereotactic radiation therapy combined with immunotherapy: augmenting the role of radiation in local and systemic treatment.

    Science.gov (United States)

    Sharabi, Andrew B; Tran, Phuoc T; Lim, Michael; Drake, Charles G; Deweese, Theodore L

    2015-05-01

    Stereotactic radiosurgery and stereotactic body radiation therapy are two contemporary radiation modalities that can treat tumors in any area of the body using highly focused radiation. Recently, immunotherapy has established itself as a viable and powerful anticancer treatment. In this review we detail the rationale supporting a combination of immunotherapy and stereotactic radiation. Additionally, we discuss the evidence for the immune stimulatory effects of focused radiation and the role that radiation may play in enhancing the systemic treatment effects of immunotherapy.

  6. Radiation therapy among atomic bomb survivors, Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Pinkston, J.A.; Antoku, Shigetoshi; Russell, W.J.

    1980-10-01

    In the continuing evaluations of atomic bomb survivors for late radiation effects, not only doses from the A-bombs but those from other radiation sources must be considered, for the latter may be concomitantly acting factors causing bias among these investigations. In the present study, among 73 Hiroshima and 22 Nagasaki Adult Health Study (AHS) subjects who reported receiving radiation therapy, from 1970 through 1979, the medical records of 72 and 20, respectively, were reviewed, and 41 Hiroshima and 14 Nagasaki subjects were confirmed to have received radiation therapy. The data obtained in the present study were pooled with those of the previous investigation on radiation therapy exposures of AHS subjects prior to 1970. A total of 190 subjects have been documented as receiving radiation therapy and their doses were estimated. Energies used in treatments and diseases treated are discussed. Malignancies developed subsequent to radiation therapy in seven cases; five after treatment for malignancies and two after treatment for benign diseases. Neoplasms of 12 AHS subjects may have been induced by earlier radiation therapy; 5 in the earlier study and 7 in the present one. These investigations underscore the need for continued documentation of exposures to ionizing radiation for medical reasons, especially from sources incurring relatively high doses. Bias in assessments of late radiation effects among A-bomb survivors can thus be avoided. (author)

  7. Laryngeal necrosis after combined chemotherapy and radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Miyaguchi, Mamoru; Kubo, Takeshi [Osaka Univ., Suita (Japan). School of Medicine; Takashima, Hitoshi [Kagawa Medical School (Japan)

    1997-08-01

    Post-radiation necrosis of the larynx is a major complication after irradiation and has become rare. Recently, combined chemotherapy and radiation therapy has been introduced for head and neck tumours. The authors report a case of laryngeal necrosis after combination therapy for a patient with cervical lymph node metastases of nasopharyngeal carcinoma and review the literature on late laryngeal necrosis. Although radiation-induced laryngeal necrosis has become a rare complication, the combination of chemotherapy and radiation therapy may increase its incidence. (author).

  8. Radiation therapy technology (radiation therapists) manpower needs 1992 comparison of radiation therapeutic technology education in Europe and the United States 1994

    International Nuclear Information System (INIS)

    Rominger, C. Jules; Owen, Jean; Thompson, Phyllis; Giordano, Patricia; Buck, Beverly; Hanks, Gerald

    1995-01-01

    The shortage of radiation therapists (radiation therapy technologists) has existed in the United States for many years. It now appears the supply may be matching the demand. This report analyzes the data from the most recent manpower study from ACR/ASTRO carried out in 1990 using the Patterns of Care Master Facility list. The report is a comparison of these figures with similar figures published in IJROBP in December, 1983. Between 1980 and 1990 the number of radiation therapists rose from 3096 to 5353, an increase of 72%. During this period of time, the number of radiation therapy machines increased 47%, and the number of patients being treated increased 30%. The total number of educational programs in radiation therapy technology increased from 101 in 1989 to 123 in 1993. The total enrollment in these programs grew from 806 in 1989 to 1591 in 1993. The number of first time examinees in radiation therapy technology by ARRT in 1983 was 387 and increased to 943 in 1994. It is apparent that as a result of the increase in the number of radiation therapy educational programs and the more effective recruitment into these program, the supply of graduating radiation therapists has reached the demand. The future needs for entry level radiation therapists should be based on current data as well as new Blue Book standards that are being developed

  9. Use of Single- versus Multiple-Fraction Palliative Radiation Therapy for Bone Metastases: Population-Based Analysis of 16,898 Courses in a Canadian Province

    International Nuclear Information System (INIS)

    Olson, Robert A.; Tiwana, Manpreet S.; Barnes, Mark; Kiraly, Andrew; Beecham, Kwamena; Miller, Stacy; Hoegler, David; Olivotto, Ivo

    2014-01-01

    Purpose: There is abundant evidence that a single fraction (SF) of palliative radiation therapy (RT) for bone metastases is equivalent to more protracted and costly multiple fraction courses. Despite this, there is low utilization of SFRT internationally. We sought to determine the utilization of SFRT in a population-based, publicly funded health care system. Methods and Materials: All consecutive patients with bone metastases treated with RT during 2007 to 2011 in British Columbia (BC) were identified. Associations between utilization of SFRT and patient and provider characteristics were investigated. Results: A total of 16,898 courses of RT were delivered to 8601 patients. SFRT was prescribed 49% of the time. There were positive relationships among SFRT utilization and primary tumor group (P<.001; most commonly in prostate cancer), worse prognosis (P<.001), increasing physician experience (P<.001), site of metastases (P<.001; least for spine metastases), and area of training (P<.001; most commonly for oncologists trained in the United Kingdom). There was wide variation in the prescription of SFRT across 5 regional cancer centers, ranging from 25.5% to 73.4%, which persisted after controlling for other, potentially confounding factors (P<.001). Conclusions: The large variability in SFRT utilization across BC Cancer Agency (BCCA) cancer centers suggests there is a strong cultural effect, where physicians' use of SFRT is influenced by their colleagues' practice. SFRT use in BC was similar to that in other Canadian and western European reports but strikingly higher than in the United States. Further work is needed to standardize SFRT prescribing practices internationally for this common indication for RT, with the potential for huge health system cost savings and substantial improvements in patients' quality of life

  10. SU-F-R-53: CT-Based Radiomics Analysis of Non-Small Cell Lung Cancer Patients Treated with Stereotactic Body Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, E; Coroller, T; Narayan, V; Agrawal, V; Hou, Y; Romano, J; Franco, I; Mak, R; Aerts, H [Brigham Women’s Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: Stereotactic body radiation therapy (SBRT) is the standard of care for medically inoperable non-small cell lung cancer (NSCLC) patients and has demonstrated excellent local control and survival. However, some patients still develop distant metastases and local recurrence, and therefore, there is a clinical need to identify patients at high-risk of disease recurrence. The aim of the current study is to use a radiomics approach to identify imaging biomarkers, based on tumor phenotype, for clinical outcomes in SBRT patients. Methods: Radiomic features were extracted from free breathing computed tomography (CT) images of 113 Stage I-II NSCLC patients treated with SBRT. Their association to and prognostic performance for distant metastasis (DM), locoregional recurrence (LRR) and survival was assessed and compared with conventional features (tumor volume and diameter) and clinical parameters (e.g. performance status, overall stage). The prognostic performance was evaluated using the concordance index (CI). Multivariate model performance was evaluated using cross validation. All p-values were corrected for multiple testing using the false discovery rate. Results: Radiomic features were associated with DM (one feature), LRR (one feature) and survival (four features). Conventional features were only associated with survival and one clinical parameter was associated with LRR and survival. One radiomic feature was significantly prognostic for DM (CI=0.670, p<0.1 from random), while none of the conventional and clinical parameters were significant for DM. The multivariate radiomic model had a higher median CI (0.671) for DM than the conventional (0.618) and clinical models (0.617). Conclusion: Radiomic features have potential to be imaging biomarkers for clinical outcomes that conventional imaging metrics and clinical parameters cannot predict in SBRT patients, such as distant metastasis. Development of a radiomics biomarker that can identify patients at high-risk of

  11. A point kernel algorithm for microbeam radiation therapy

    Science.gov (United States)

    Debus, Charlotte; Oelfke, Uwe; Bartzsch, Stefan

    2017-11-01

    Microbeam radiation therapy (MRT) is a treatment approach in radiation therapy where the treatment field is spatially fractionated into arrays of a few tens of micrometre wide planar beams of unusually high peak doses separated by low dose regions of several hundred micrometre width. In preclinical studies, this treatment approach has proven to spare normal tissue more effectively than conventional radiation therapy, while being equally efficient in tumour control. So far dose calculations in MRT, a prerequisite for future clinical applications are based on Monte Carlo simulations. However, they are computationally expensive, since scoring volumes have to be small. In this article a kernel based dose calculation algorithm is presented that splits the calculation into photon and electron mediated energy transport, and performs the calculation of peak and valley doses in typical MRT treatment fields within a few minutes. Kernels are analytically calculated depending on the energy spectrum and material composition. In various homogeneous materials peak, valley doses and microbeam profiles are calculated and compared to Monte Carlo simulations. For a microbeam exposure of an anthropomorphic head phantom calculated dose values are compared to measurements and Monte Carlo calculations. Except for regions close to material interfaces calculated peak dose values match Monte Carlo results within 4% and valley dose values within 8% deviation. No significant differences are observed between profiles calculated by the kernel algorithm and Monte Carlo simulations. Measurements in the head phantom agree within 4% in the peak and within 10% in the valley region. The presented algorithm is attached to the treatment planning platform VIRTUOS. It was and is used for dose calculations in preclinical and pet-clinical trials at the biomedical beamline ID17 of the European synchrotron radiation facility in Grenoble, France.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Gunther, Jillian R. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Sato, Mariko; Chintagumpala, Murali [Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Texas Children' s Cancer Center, Houston, Texas (United States); Ketonen, Leena [Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Jones, Jeremy Y. [Department of Pediatric Radiology, Texas Children' s Hospital, Houston, Texas (United States); Allen, Pamela K. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Paulino, Arnold C. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Texas Children' s Cancer Center, Houston, Texas (United States); Okcu, M. Fatih; Su, Jack M. [Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Texas Children' s Cancer Center, Houston, Texas (United States); Weinberg, Jeffrey [Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Boehling, Nicholas S. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Khatua, Soumen [Department of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Adesina, Adekunle [Department of Pathology, Baylor College of Medicine, Texas Children' s Hospital, Houston, Texas (United States); Dauser, Robert; Whitehead, William E. [Department of Neurosurgery, Texas Children' s Hospital, Houston, Texas (United States); Mahajan, Anita, E-mail: amahajan@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2015-09-01

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

  14. Modern role and issues of radiation therapy for benign diseases

    International Nuclear Information System (INIS)

    Miyashita, Tsuguhiro; Tateno, Atsushi; Kumazaki, Tatsuo

    1999-01-01

    Cases of radiation therapy for benign diseases have diminished in number because of recent alternative methods and knowledge about radiation carcinogenesis. In contrast to this tendency, our cases of benign diseases have recently increased. The facts made us reconsider today's radiation therapy of benign diseases. We reviewed 349 patients who were diagnosed as having benign tumors or non-neoplastic conditions and treated by radiation therapy in the past sixteen years. Analyzed items were the annual transition of treatment number, sorts of diseases, patients' age and sex, and the goal of therapy. Of all radiation therapy patients, benign diseases account for 9.26%. The annual percentages were 0.5%, 6.0%, 11.2% and 13.7% at intervals of five years since 1982. The majority was 246 post-operative irradiation for keloids (71%) and 41 pituitary adenomas (12%). Compared with malignant tumors, benign disease patients were statistically younger and female-dominant. Applications of radiation therapy in keloids and pituitary adenomas had definite goals, but were unclear in other rare diseases. Benign diseases should be treated by radiation therapy as the second or third option, provided the patients have serious symptoms and their diseases do not respond to other modalities. It seems to be widely accepted that favorite cases such as keloids and pituitary adenomas are treated by radiation therapy. But, optimal radiation therapies for other rare benign diseases have not been established. Therefore, the building of databases on radiation therapy on benign diseases should be pursued. Since benign disease patients were young and female-dominant and had many remaining years, their carcinogenicity potential should be considered. (author)

  15. Near Real-Time Assessment of Anatomic and Dosimetric Variations for Head and Neck Radiation Therapy via Graphics Processing Unit–based Dose Deformation Framework

    International Nuclear Information System (INIS)

    Qi, X. Sharon; Santhanam, Anand; Neylon, John; Min, Yugang; Armstrong, Tess; Sheng, Ke; Staton, Robert J.; Pukala, Jason; Pham, Andrew; Low, Daniel A.; Lee, Steve P.; Steinberg, Michael; Manon, Rafael; Chen, Allen M.; Kupelian, Patrick

    2015-01-01

    Purpose: The purpose of this study was to systematically monitor anatomic variations and their dosimetric consequences during intensity modulated radiation therapy (IMRT) for head and neck (H&N) cancer by using a graphics processing unit (GPU)-based deformable image registration (DIR) framework. Methods and Materials: Eleven IMRT H&N patients undergoing IMRT with daily megavoltage computed tomography (CT) and weekly kilovoltage CT (kVCT) scans were included in this analysis. Pretreatment kVCTs were automatically registered with their corresponding planning CTs through a GPU-based DIR framework. The deformation of each contoured structure in the H&N region was computed to account for nonrigid change in the patient setup. The Jacobian determinant of the planning target volumes and the surrounding critical structures were used to quantify anatomical volume changes. The actual delivered dose was calculated accounting for the organ deformation. The dose distribution uncertainties due to registration errors were estimated using a landmark-based gamma evaluation. Results: Dramatic interfractional anatomic changes were observed. During the treatment course of 6 to 7 weeks, the parotid gland volumes changed up to 34.7%, and the center-of-mass displacement of the 2 parotid glands varied in the range of 0.9 to 8.8 mm. For the primary treatment volume, the cumulative minimum and mean and equivalent uniform doses assessed by the weekly kVCTs were lower than the planned doses by up to 14.9% (P=.14), 2% (P=.39), and 7.3% (P=.05), respectively. The cumulative mean doses were significantly higher than the planned dose for the left parotid (P=.03) and right parotid glands (P=.006). The computation including DIR and dose accumulation was ultrafast (∼45 seconds) with registration accuracy at the subvoxel level. Conclusions: A systematic analysis of anatomic variations in the H&N region and their dosimetric consequences is critical in improving treatment efficacy. Nearly real

  16. Near Real-Time Assessment of Anatomic and Dosimetric Variations for Head and Neck Radiation Therapy via Graphics Processing Unit–based Dose Deformation Framework

    Energy Technology Data Exchange (ETDEWEB)

    Qi, X. Sharon, E-mail: xqi@mednet.ucla.edu [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Santhanam, Anand; Neylon, John; Min, Yugang; Armstrong, Tess; Sheng, Ke [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Staton, Robert J.; Pukala, Jason [Department of Radiation Oncology, UF Health Cancer Center - Orlando Health, Orlando, Florida (United States); Pham, Andrew; Low, Daniel A.; Lee, Steve P. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Steinberg, Michael; Manon, Rafael [Department of Radiation Oncology, UF Health Cancer Center - Orlando Health, Orlando, Florida (United States); Chen, Allen M.; Kupelian, Patrick [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States)

    2015-06-01

    Purpose: The purpose of this study was to systematically monitor anatomic variations and their dosimetric consequences during intensity modulated radiation therapy (IMRT) for head and neck (H&N) cancer by using a graphics processing unit (GPU)-based deformable image registration (DIR) framework. Methods and Materials: Eleven IMRT H&N patients undergoing IMRT with daily megavoltage computed tomography (CT) and weekly kilovoltage CT (kVCT) scans were included in this analysis. Pretreatment kVCTs were automatically registered with their corresponding planning CTs through a GPU-based DIR framework. The deformation of each contoured structure in the H&N region was computed to account for nonrigid change in the patient setup. The Jacobian determinant of the planning target volumes and the surrounding critical structures were used to quantify anatomical volume changes. The actual delivered dose was calculated accounting for the organ deformation. The dose distribution uncertainties due to registration errors were estimated using a landmark-based gamma evaluation. Results: Dramatic interfractional anatomic changes were observed. During the treatment course of 6 to 7 weeks, the parotid gland volumes changed up to 34.7%, and the center-of-mass displacement of the 2 parotid glands varied in the range of 0.9 to 8.8 mm. For the primary treatment volume, the cumulative minimum and mean and equivalent uniform doses assessed by the weekly kVCTs were lower than the planned doses by up to 14.9% (P=.14), 2% (P=.39), and 7.3% (P=.05), respectively. The cumulative mean doses were significantly higher than the planned dose for the left parotid (P=.03) and right parotid glands (P=.006). The computation including DIR and dose accumulation was ultrafast (∼45 seconds) with registration accuracy at the subvoxel level. Conclusions: A systematic analysis of anatomic variations in the H&N region and their dosimetric consequences is critical in improving treatment efficacy. Nearly real

  17. Using Oxygen “Microbubbles” To Improve Radiation Therapy

    Science.gov (United States)

    Oxygen-carrying “microbubbles” could potentially improve the effectiveness of radiation therapy in the treatment of breast cancer, findings from a study in mice suggest. Using the bubbles along with radiation slowed tumor growth more than radiation alone, as this NCI Cancer Currents post reports.

  18. Occurrence of BOOP outside radiation field after radiation therapy for small cell lung cancer

    International Nuclear Information System (INIS)

    Hamanishi, Tohru; Oida, Kazukiyo; Morimatu, Takafumi

    2001-01-01

    We report a case of bronchiolitis obliterans organizing pneumonia (BOOP) that occurred outside the radiation field after radiation therapy for small cell lung cancer. A 74-year-old woman received chemotherapy and a total of 60 Gy of radiation therapy to the right hilum and mediastinum for small cell carcinoma of the suprahilar area of the right lung. Radiation pneumonitis developed within the radiation port 3 months after the completion of radiation therapy. She complained of cough and was admitted 7 months after completion of the radiation therapy. Chest radiography and computed tomography demonstrated peripheral alveolar opacities outside the radiation field on the side contralateral to that receiving the radiation therapy. Bronchoalveolar lavage showed that the total cell count was increased, with a markedly increased percentage of lymphocytes. Transbronchial lung biopsy revealed a histologic pattern consistent with BOOP. Treatment with corticosteroids resulted in rapid improvement of the symptoms and complete resolution of the radiographic abnormalities of the left lung. Although some cases of BOOP following radiation therapy for breast cancer have been reported, none of BOOP after radiation therapy for lung cancer have appeared in the literature. (author)

  19. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a (60)Co Magnetic Resonance Image Guidance Radiation Therapy System

    DEFF Research Database (Denmark)

    Wooten, H Omar; Green, Olga; Yang, Min

    2015-01-01

    PURPOSE: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating (60)Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. METHODS AND MATERIALS...

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

    Science.gov (United States)

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

    2012-01-01

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

  1. CT follow-up after radiation therapy for pituitary adenomas

    International Nuclear Information System (INIS)

    Rush, S.C.; Newall, J.

    1988-01-01

    Between 1973 and 1985, 105 patients received radiation therapy as all or part of their treatment for pituitary tumor at the New York University Medical Center. Of these, 48 patients underwent computed tomography (CT) at a minimum of 2 years following treatment, with detailed reports available for analysis of tumor regression. There were 28 men with a median age of 46 years (range, 18-71 years) and 20 women with a median age of 53 years (range, 28-80 years). Tumors were classified as secretory in 23 patients, nonsecretory in 21, and undetermined in four. Sixteen patients were treated with radiation therapy alone, 23 patients with surgery and radiation therapy, and the other with bromocriptine and radiation therapy, with or without surgery. With a median follow-up of 5 years (range, 2-14 years), 16 patients developed an empty sella, 25 patients had residual sellar mass, and seven patients had persistent extrasellar components or no change in their intrasellar mass. Among patients who did not have hypopituitarism at the inception of radiation therapy, five of 13 with empty sellas and 12 of 22 with residual mass subsequently required therapy. The authors conclude that residual mass is commonly found in long-term follow-up after radiation therapy, that isolated imaging studies revealing such findings after treatment in no way herald a diagnosis of recurrence, and that hypopituitarism following pituitary radiation therapy does not correlate with the ablation or persistence of tissue within the sella

  2. Evaluation of selection criteria for graduate students in radiation therapy.

    Science.gov (United States)

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

    2006-12-01

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

  3. Cellular therapy to treat ionizing radiation-induced cutaneous radiation syndrome: 2 cases report

    International Nuclear Information System (INIS)

    Benderitter, M.; Chapel, A.; Trompier, F.; Clairand, I.; Bottolier-Depois, J.F.; Gourmelon, P.; Bey, E.; Lataillade, J.J.

    2008-01-01

    Full Text: Localized irradiation at high dose exposition could induce severe radiation burns characterized by the occurrence of unpredictable successive inflammatory waves leading to the extension in surface and depth of necrotic processes. The medical management of these severe radiation burns remains today a challenging issue unresolved by the classical therapeutical approach. For the first time, two victims (accident of Chile, 2006 and accident of Senegal, 2007) accidentally exposed to an iridium gammagraphy radioactive source experienced a new and innovative therapeutic strategy combining dosimetry-guided surgery lesion excision and injection of MSC. The clinical evolution was remarkable. The clinical transfer of this therapeutic option was possible based on the research perform in the Institute and the IRSN/Percy hospital cooperation. Our data suggested that cellular therapy based on Mesenchymal Stem Cell (MSC) injection could be used to repair numerous injured tissues. We have studied the potential use of human MSC (hMSC) in order to limit radiation-induced skin lesions. Our pre-clinical data suggest a possible use of hMSC for the treatment of the early phase of the cutaneous radiation syndrome. The understanding of the precise healing mechanisms of hMSC in animal model is under investigation. These results will be helpful to generalize this innovative therapy to the treatment of other radiological complications. (author)

  4. Postoperative radiation therapy for lung cancer

    International Nuclear Information System (INIS)

    Teshima, Teruki; Chatani, Masashi; Inoue, Toshihiko; Kurokawa, Eiji; Kodama, Ken; Doi, Osamu

    1987-01-01

    From January 1978 through December 1982, a total of 241 cases with lung cancer underwent surgery. Twenty-nine cases (operative death: 7, relative non-curative operation: 13, exploratory thoracotomy: 9) were excluded because they did not receive radiation therapy (RT). The remaining 212 cases were available for this analysis. Forty-two of them were treated with RT postoperatively. Three-year survival rates according to curability in the non-RT and RT groups were 83 % and 71 % (NS) in the curative operation group. In the relatively curative operation group, the corresponding figures were 40 % and 33 % (NS), and in the absolutely non-curative operation group, 3 % and 20 % (p < 0.01), respectively. The analysis of background factors revealed that in the curative operation group the rate of combined resection and in the relatively curative operation group pT3 and combined resection were significantly higher in the RT group than non-RT group. In the absolutely non-curative operation group, the rate of pM1 was significantly lower in RT group than the non-RT group. The pattern of failure of the RT group by histology was analysed. Local and regional failure was most common in the squamous cell carcinoma group and distant failure in the adenocarcinoma group. However, in the adenocarcinoma group local and regional or supraclavicular lymph node failure was also frequently noted. The relationship between the radiation field and local and regional or supraclavicular lymph node failure was analysed. In the squamous cell carcinoma group, in-field failure was most common, whereas in the adenocarcinoma group, outside (marginal) failure was common, especially in the supraclavicular lymph nodes. Concerning squamous cell carcinoma, microscopic or macroscopic residual tumor at the surgical margin, which includes the chest wall, stump (BS or VS) and pericardium was well controlled in each operation group with more than 50 Gy of RT. (J.P.N.)

  5. Scatter factors assessment in microbeam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  6. Radiation-induced myocardial perfusion abnormalities in breast cancer patients following external beam radiation therapy

    Directory of Open Access Journals (Sweden)

    Mohammad Eftekhari

    2015-01-01

    Full Text Available Objective(s: Radiation therapy for breast cancer can induce myocardial capillary injury and increase cardiovascular morbidity and mortality. A prospective cohort was conducted to study the prevalence of myocardial perfusion abnormalities following radiation therapy of left-sided breast cancer patients as compared to those with right–sided cancer. Methods: To minimize potential confounding factors, only those patients with low 10-year risk of coronary artery disease (based on Framingham risk scoring were included. All patients were initially treated by modified radical mastectomy and then were managed by postoperative 3D Conformal Radiation Therapy (CRT to the surgical bed with an additional 1-cm margin, delivered by 46-50 Gy (in 2 Gy daily fractions over a 5-week course. The same dose-adjusted chemotherapy regimen (including anthracyclines, cyclophosphamide and taxol was given to all patients. Six months after radiation therapy, all patients underwent cardiac SPECT for the evaluation of myocardial perfusion. Results: A total of 71 patients with a mean age of 45.3±7.2 years [35 patients with leftsided breast cancer (exposed and 36 patients with right-sided cancer (controls] were enrolled. Dose-volume histogram (DVH [showing the percentage of the heart exposed to >50% of radiation] was significantly higher in patients with left-sided breast cancer. Visual interpretation detected perfusion abnormalities in 42.9% of cases and 16.7% of controls (P=0.02, Odds ratio=1.46. In semiquantitative segmental analysis, only apical (28.6% versus 8.3%, P=0.03 and anterolateral (17.1% versus 2.8%, P=0.049 walls showed significantly reduced myocardial perfusion in the exposed group. Summed Stress Score (SSS of>3 was observed in twelve cases (34.3%, while in five of the controls (13.9%,(Odds ratio=1.3. There was no significant difference between the groups regarding left ventricular ejection fraction. Conclusion: The risk of radiation induced myocardial

  7. Degree and therapy of acute radiation syndromes. Introduction of a suggestion on acute radiation sickness therapy made by strategic national stockpile radiation working group of USA. part 2

    International Nuclear Information System (INIS)

    Min Rui; Pan Zhen; Li Yu

    2005-01-01

    Recommendations based on radiation dose and physiologic response are made for treatment of the hematopoietic syndrome. Therapy includes treatment with hematopoietic cytokines, blood transfusion, and stem-cell transplantation in selected cases. Additional medical management based on the evolution of clinical signs and symptoms includes the use of antimicrobial agents (quinolones, antiviral therapy, and antifungal agents), antiemetic agents, and analgesic agents. Because of the strong psychological impact of a possible radiation exposure, psychosocial support will be required for those exposed, regardless of the dose, as well as for family and friends. Treatment of pregnant women must account for risk to the fetus. For terrorist or accidental events involving exposure to radioiodines, prophylaxis against malignant disease of the thyroid is also recommended, particularly for children and adolescents. (authors)

  8. New modalities in radiation therapy for treatment of cancer

    International Nuclear Information System (INIS)

    Kumar, Deepak

    2013-01-01

    Cancer is a generic term for a large group of diseases characterized by rapid creation of abnormal cells that grow beyond their usual boundaries, and which can then invade adjoining parts of the body and spread to other organs. Cancer mortality is the second and most common cause of death in the USA and in most European countries. In India, it is the fourth leading disease and the major cause of death. Cancer remains one of the most dreadful disease and approximately ten million cases of cancer occur in the world every year. The course of cancer treatment depends on the type of cancer, its location, and its state of advancement. Cancer is treated with surgery, chemotherapy, radiation therapy, hormone therapy, biological therapy and targeted therapy. Radiation therapy is an important an affordable modality for cancer treatment with minimal side effects. Radiation kills cancer cells with high-energy rays targeted directly to the tumor. Radiation therapy works by damaging the DNA and preventing its replication: therefore, it preferentially kills cancer cells, which rapidly divides. Radiation therapy is used for cure, control, and palliation of cancers in more than 60% of cancer patients. The goal of radiotherapy is to treat the cancer and spare the normal tissue as much as possible. Advances have been made in radiotherapy that allow delivery of higher doses of radiation to the tumor while sparing a greater amount of surrounding tissue, thus achieving more cures and fewer acute and long-term side effects. Technological advances and research are being continued to result in improvements in the field. Several new devices and techniques are used these days in radiotherapy for accurate treatment of cancer. Teletherapy (external radiation therapy) used focused radiation beams targeting well defined tumor through extremely detailed imaging scans. Conventional external beam radiation therapy (2DXRT) is delivered via two-dimensional beams using linear accelerator machines (X

  9. SU-E-J-244: Development and Validation of a Knowledge Based Planning Model for External Beam Radiation Therapy of Locally Advanced Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z; Kennedy, A [Sarah Cannon, Nashville, TN (United States); Larsen, E; Hayes, C; Grow, A [North Florida Cancer Center, Gainesville, FL (United States); Bahamondes, S.; Zheng, Y; Wu, X [JFK Comprehensive Cancer Institute, Lake Worth, FL (United States); Choi, M; Pai, S [Good Samaritan Hospital, Los Gatos, CA (United States); Li, J [Doctors Hospital of Augusta, Augusta, GA (United States); Cranford, K [Trident Medical Center, Charleston, SC (United States)

    2015-06-15

    Purpose: The study aims to develop and validate a knowledge based planning (KBP) model for external beam radiation therapy of locally advanced non-small cell lung cancer (LA-NSCLC). Methods: RapidPlan™ technology was used to develop a lung KBP model. Plans from 65 patients with LA-NSCLC were used to train the model. 25 patients were treated with VMAT, and the other patients were treated with IMRT. Organs-at-risk (OARs) included right lung, left lung, heart, esophagus, and spinal cord. DVH and geometric distribution DVH were extracted from the treated plans. The model was trained using principal component analysis and step-wise multiple regression. Box plot and regression plot tools were used to identify geometric outliers and dosimetry outliers and help fine-tune the model. The validation was performed by (a) comparing predicted DVH boundaries to actual DVHs of 63 patients and (b) using an independent set of treatment planning data. Results: 63 out of 65 plans were included in the final KBP model with PTV volume ranging from 102.5cc to 1450.2cc. Total treatment dose prescription varied from 50Gy to 70Gy based on institutional guidelines. One patient was excluded due to geometric outlier where 2.18cc of spinal cord was included in PTV. The other patient was excluded due to dosimetric outlier where the dose sparing to spinal cord was heavily enforced in the clinical plan. Target volume, OAR volume, OAR overlap volume percentage to target, and OAR out-of-field volume were included in the trained model. Lungs and heart had two principal component scores of GEDVH, whereas spinal cord and esophagus had three in the final model. Predicted DVH band (mean ±1 standard deviation) represented 66.2±3.6% of all DVHs. Conclusion: A KBP model was developed and validated for radiotherapy of LA-NSCLC in a commercial treatment planning system. The clinical implementation may improve the consistency of IMRT/VMAT planning.

  10. Beam’s-eye-view dosimetrics (BEVD) guided rotational station parameter optimized radiation therapy (SPORT) planning based on reweighted total-variation minimization

    Science.gov (United States)

    Kim, Hojin; Li, Ruijiang; Lee, Rena; Xing, Lei

    2015-03-01

    Conventional VMAT optimizes aperture shapes and weights at uniformly sampled stations, which is a generalization of the concept of a control point. Recently, rotational station parameter optimized radiation therapy (SPORT) has been proposed to improve the plan quality by inserting beams to the regions that demand additional intensity modulations, thus formulating non-uniform beam sampling. This work presents a new rotational SPORT planning strategy based on reweighted total-variation (TV) minimization (min.), using beam’s-eye-view dosimetrics (BEVD) guided beam selection. The convex programming based reweighted TV min. assures the simplified fluence-map, which facilitates single-aperture selection at each station for single-arc delivery. For the rotational arc treatment planning and non-uniform beam angle setting, the mathematical model needs to be modified by additional penalty term describing the fluence-map similarity and by determination of appropriate angular weighting factors. The proposed algorithm with additional penalty term is capable of achieving more efficient and deliverable plans adaptive to the conventional VMAT and SPORT planning schemes by reducing the dose delivery time about 5 to 10 s in three clinical cases (one prostate and two head-and-neck (HN) cases with a single and multiple targets). The BEVD guided beam selection provides effective and yet easy calculating methodology to select angles for denser, non-uniform angular sampling in SPORT planning. Our BEVD guided SPORT treatment schemes improve the dose sparing to femoral heads in the prostate and brainstem, parotid glands and oral cavity in the two HN cases, where the mean dose reduction of those organs ranges from 0.5 to 2.5 Gy. Also, it increases the conformation number assessing the dose conformity to the target from 0.84, 0.75 and 0.74 to 0.86, 0.79 and 0.80 in the prostate and two HN cases, while preserving the delivery efficiency, relative to conventional single-arc VMAT plans.

  11. Beam’s-eye-view dosimetrics (BEVD) guided rotational station parameter optimized radiation therapy (SPORT) planning based on reweighted total-variation minimization

    International Nuclear Information System (INIS)

    Kim, Hojin; Li, Ruijiang; Xing, Lei; Lee, Rena

    2015-01-01

    Conventional VMAT optimizes aperture shapes and weights at uniformly sampled stations, which is a generalization of the concept of a control point. Recently, rotational station parameter optimized radiation therapy (SPORT) has been proposed to improve the plan quality by inserting beams to the regions that demand additional intensity modulations, thus formulating non-uniform beam sampling. This work presents a new rotational SPORT planning strategy based on reweighted total-variation (TV) minimization (min.), using beam’s-eye-view dosimetrics (BEVD) guided beam selection. The convex programming based reweighted TV min. assures the simplified fluence-map, which facilitates single-aperture selection at each station for single-arc delivery. For the rotational arc treatment planning and non-uniform beam angle setting, the mathematical model needs to be modified by additional penalty term describing the fluence-map similarity and by determination of appropriate angular weighting factors. The proposed algorithm with additional penalty term is capable of achieving more efficient and deliverable plans adaptive to the conventional VMAT and SPORT planning schemes by reducing the dose delivery time about 5 to 10 s in three clinical cases (one prostate and two head-and-neck (HN) cases with a single and multiple targets). The BEVD guided beam selection provides effective and yet easy calculating methodology to select angles for denser, non-uniform angular sampling in SPORT planning. Our BEVD guided SPORT treatment schemes improve the dose sparing to femoral heads in the prostate and brainstem, parotid glands and oral cavity in the two HN cases, where the mean dose reduction of those organs ranges from 0.5 to 2.5 Gy. Also, it increases the conformation number assessing the dose conformity to the target from 0.84, 0.75 and 0.74 to 0.86, 0.79 and 0.80 in the prostate and two HN cases, while preserving the delivery efficiency, relative to conventional single-arc VMAT plans

  12. Measurement-based Monte Carlo simulation of high definition dose evaluation for nasopharyngeal cancer patients treated by using intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Yeh, C.Y.; Tung, C.J.; Lee, C.C.; Lin, M.H.; Chao, T.C.

    2014-01-01

    Measurement-based Monte Carlo (MBMC) simulation using a high definition (HD) phantom was used to evaluate the dose distribution in nasopharyngeal cancer (NPC) patients treated with intensity modulated radiation therapy (IMRT). Around nasopharyngeal cavity, there exists many small volume organs-at-risk (OARs) such as the optic nerves, auditory nerves, cochlea, and semicircular canal which necessitate the use of a high definition phantom for accurate and correct dose evaluation. The aim of this research was to study the advantages of using an HD phantom for MBMC simulation in NPC patients treated with IMRT. The MBMC simulation in this study was based on the IMRT treatment plan of three NPC patients generated by the anisotropic analytical algorithm (AAA) of the Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA, USA) using a calculation grid of 2 mm 2 . The NPC tumor was treated to a cumulative dose of 7000 cGy in 35 fractions using the shrinking-field sequential IMRT (SIMRT) method. The BEAMnrc MC Code was used to simulate a Varian EX21 linear accelerator treatment head. The HD phantom contained 0.5 × 0.5 × 1 mm 3 voxels for the nasopharyngeal area and 0.5 × 0.5 × 3 mm 3 for the rest of the head area. An efficiency map was obtained for the amorphous silicon aS1000 electronic portal imaging device (EPID) to adjust the weighting of each particle in the phase-space file for each IMRT beam. Our analysis revealed that small volume organs such as the eighth cranial nerve, semicircular canal, cochlea and external auditory canal showed an absolute dose difference of ≥200 cGy, while the dose difference for larger organs such as the parotid glands and tumor was negligible for the MBMC simulation using the HD phantom. The HD phantom was found to be suitable for Monte Carlo dose volume analysis of small volume organs. - Highlights: • HD dose evaluation for IMRT of NPC patients have been verified by the MC method. • MC results shows

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

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Katrina, E-mail: Trinabena23@gmail.com; Lenards, Nishele; Holson, Janice

    2016-04-01

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

  14. Implementation of MRI gel dosimetry in radiation therapy

    International Nuclear Information System (INIS)

    Baeck, S.Aa.J.

    1998-12-01

    Gel dosimetry was used together with magnetic resonance imaging (MRI) to measure three-dimensional absorbed dose distributions in radiation therapy. Two different dosimeters were studied: ferrous- and monomer gel, based on the principles of radiation-induced oxidation and polymerisation, respectively. Single clinical electron and photon beams were evaluated and gel dose distributions were mainly within 2% of conventional detector results. The ferrous-gel was also used for clinical proton beams. A decrease in signal per absorbed dose was found close to the end of the range of the protons (15-20%). This effect was explained as a linear energy transfer dependence, further supported with Monte Carlo simulations. A method for analysing and comparing data from treatment planning system (TPS) and gel measurements was developed. The method enables a new pixel by pixel evaluation, isodose comparison and dose volume histogram verification. Two standard clinical radiation therapy procedures were examined using the developed TPS verification method. The treatment regimes included several beams of different radiation qualities. The TPS calculated data were in very good agreement with the dose distribution measured by the ferrous-gel. However, in a beam abutment region, larger dose difference was found. Beam adjustment errors and a minor TPS underestimation of the lateral scatter contribution outside the primary electron beam may explain the discrepancy. The overall uncertainty in the ferrous-gel dose determination was considerably reduced using an optimised MRI acquisition protocol and a new MRI scanner. The relative dose uncertainty was found to be better than 3.3% for all dose levels (95% confidence level). Using the method developed for comparing measured gel data with calculated treatment plans, the gel dosimetry method was proven to be a useful tool for radiation treatment planning verification

  15. Implementation of MRI gel dosimetry in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Baeck, S.Aa.J

    1998-12-01

    Gel dosimetry was used together with magnetic resonance imaging (MRI) to measure three-dimensional absorbed dose distributions in radiation therapy. Two different dosimeters were studied: ferrous- and monomer gel, based on the principles of radiation-induced oxidation and polymerisation, respectively. Single clinical electron and photon beams were evaluated and gel dose distributions were mainly within 2% of conventional detector results. The ferrous-gel was also used for clinical proton beams. A decrease in signal per absorbed dose was found close to the end of the range of the protons (15-20%). This effect was explained as a linear energy transfer dependence, further supported with Monte Carlo simulations. A method for analysing and comparing data from treatment planning system (TPS) and gel measurements was developed. The method enables a new pixel by pixel evaluation, isodose comparison and dose volume histogram verification. Two standard clinical radiation therapy procedures were examined using the developed TPS verification method. The treatment regimes included several beams of different radiation qualities. The TPS calculated data were in very good agreement with the dose distribution measured by the ferrous-gel. However, in a beam abutment region, larger dose difference was found. Beam adjustment errors and a minor TPS underestimation of the lateral scatter contribution outside the primary electron beam may explain the discrepancy. The overall uncertainty in the ferrous-gel dose determination was considerably reduced using an optimised MRI acquisition protocol and a new MRI scanner. The relative dose uncertainty was found to be better than 3.3% for all dose levels (95% confidence level). Using the method developed for comparing measured gel data with calculated treatment plans, the gel dosimetry method was proven to be a useful tool for radiation treatment planning verification 103 refs, 20 figs, 6 tabs

  16. Two case reports of a cerebrovascular disorder after radiation therapy

    International Nuclear Information System (INIS)

    Ono, Jiro; Mimaki, Takashi; Tagawa, Tetsuzo

    1985-01-01

    The use of radiation therapy has significantly improved the prognosis of certain brain tumors. However, a few patients have been reported who developed cerebrovasculopathy accompanying transient ischemic attacks several months to several years after radiation therapy. The present report described cerebrovascular disorders after radiation therapy for brain tumors. The first case was an 8-year-6-month-old boy treated with a total dose of 5,200 rads after partial removal of a right periventricular astrocytoma extending into the thalamus. Two years and 7 months after completion of the radiation therapy, he showed transient ischemic attacks of numbness in the right upper limb and right hemiparesis. Arteriography revealed stenosis or occlusion of the anterior and middle cerebral arteries. Preoperative arteriography did not show occlusion nor narrowing of the cerebral arteries. The second case was a 2-year-8-month-old boy diagnosed as diencephalic syndrome, because of marked emaciation and a huge tumor mass expanding into the diencephalon and frontal lobe on the brain CT scan. He was irradiated with up to 5,000 rads. Seven months after radiation therapy, he developed transient right hemiparesis. Arteriography revealed stenosis or occlusion of the middle sized cerebral arteries. Although radiation therapy is acceptable in children with certain brain tumors, and very few patients develop postradiation vasculopathy, the risk of radiation therapy requires more careful consideration in the treatment of intracranial tumors. (author)

  17. Treatment of Recurrent Chordomas by Percutaneous Ethanol Injection Therapy and Radiation Therapy

    International Nuclear Information System (INIS)

    Nakajo, M.; Ohkubo, K.; Fukukura, Y.; Nandate, T.; Nakajo, M.

    2006-01-01

    We report a case of recurrent sacral chordomas that have been successfully controlled by the combination therapy of percutaneous ethanol injection therapy (PEIT) and radiation therapy in a 71-year-old man. PEIT may be one of the adjuvant therapies for recurrent chordomas

  18. Phantom dosimetry at 15 MV conformal radiation therapy

    International Nuclear Information System (INIS)

    Thompson, Larissa; Campos, Tarcisio P.R.

    2015-01-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  19. Phantom dosimetry at 15 MV conformal radiation therapy

    International Nuclear Information System (INIS)

    Thompson, Larissa; Campos, Tarcisio P.R.; Dias, Humberto G.

    2013-01-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  20. Phantom dosimetry at 15 MV conformal radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larissa; Campos, Tarcisio P.R., E-mail: larissathompson@hotmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Dias, Humberto G., E-mail: fisicamedica.hl@mariopenna.org.br [Luxemburgo Hospital, Mario Penna Institute, Belo Horizonte, MG (Brazil)

    2015-07-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  1. Phantom dosimetry at 15 MV conformal radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larissa; Campos, Tarcisio P.R., E-mail: larissathompson@hotmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Minas Gerais, MG (Brazil). Dept. de Engenharia Nuclear; Dias, Humberto G., E-mail: fisicamedica.hl@mariopenna.org.br [Instituto Mario Penna, Minas Gerais, MG (Brazil). Hospital Luxemburgo

    2013-07-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  2. Cost-containment in hypofractionated radiation therapy: a literature review.

    Science.gov (United States)

    Hunter, Darren; Mauldon, Emily; Anderson, Nigel

    2018-03-13

    Recent technological advances in radiation therapy have allowed for greater accuracy in planning and treatment delivery. The development of hypofractionated radiation treatment regimens is an example, and has the potential to decrease the cost per episode of care, relative to conventional treatments. Our aim was to analyse published literature on the cost-effectiveness and budgetary implications of hypofractionated radiation therapy. As such, this article will quantify the projected health care cost savings and address the optimal means of treatment delivery, associated patient outcomes, and implications arising from an increased use of hypofractionated regimens. © 2018 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.

  3. Radiation therapy for the solitary plasmacytoma

    Directory of Open Access Journals (Sweden)

    Esengül Koçak

    2010-06-01

    Full Text Available Plasma-cell neoplasms are classically categorized into four groups as: multiple myeloma (MM, plasma-cell leukemias, solitary plasmacytomas (SP of the bone (SPB, and extramedullary plasmacytomas (EMP. These tumors may be described as localized or diffuse in presentation. Localized plasma-cell neoplasms are rare, and include SP of the skeletal system, accounting for 2-5% of all plasma-cell neoplasms, and EMP of soft tissue, accounting for approximately 3% of all such neoplasms. SP is defined as a solitary mass of neoplastic plasma cells either in the bone marrow or in various soft tissue sites. There appears to be a continuum in which SP often progresses to MM. The main treatment modality for SP is radiation therapy (RT. However, there are no conclusive data in the literature on the optimal RT dose for SP. This review describes the interrelationship of plasma-cell neoplasms, and attempts to determine the minimal RT dose required to obtain local control.

  4. Radianttrademark Liquid Radioisotope Intravascular Radiation Therapy System

    International Nuclear Information System (INIS)

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

    1998-01-01

    RADIANTtrademark is manufactured by United States Surgical Corporation, Vascular Therapies Division, (formerly Progressive Angioplasty Systems). The system comprises a liquid β-radiation source, a shielded isolation/transfer device (ISAT), modified over-the-wire or rapid exchange delivery balloons, and accessory kits. The liquid β-source is Rhenium-188 in the form of sodium perrhenate (NaReO 4 ), Rhenium-188 is primarily a β-emitter with a physical half-life of 17.0 hours. The maximum energy of the β-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 Championtrademark over-the-wire, and TNTtrademark rapid exchange stent delivery balloons. These balloons have thickened polyethylene walls to augment puncture resistance; dual radio-opaque markers and specially configured connectors

  5. Stereotactic radiation therapy for large vestibular schwannomas

    International Nuclear Information System (INIS)

    Mandl, Ellen S.; Meijer, Otto W.M.; Slotman, Ben J.; Vandertop, W. Peter; Peerdeman, Saskia M.

    2010-01-01

    Background and purpose: To evaluate the morbidity and tumor-control rate in the treatment of large vestibular schwannomas (VS) after stereotactic radiation therapy in our institution. Material and methods: Twenty-five consecutive patients (17 men, 8 women) with large VS (diameter 3.0 cm or larger), treated with stereotactic radiotherapy (SRT) or stereotactic radiosurgery (SRS) between 1992 and 2007, were retrospectively studied after a mean follow-up period of three years with respect to tumor-control rate and complications. Results: Actuarial 5-year maintenance of pre-treatment hearing level probability of 30% was achieved. Five of 17 patients suffered permanent new facial nerve dysfunction. The actuarial 5-year facial nerve preservation probability was 80%. Permanent new trigeminal nerve neuropathy occurred in two of 15 patients, resulting in an actuarial 5-year trigeminal nerve preservation probability of 85%. Tumor progression occurred in four of 25 (16%) patients. The overall 5-year tumor control probability was 82%. Conclusion: Increased morbidity rates were found in patients with large VS treated with SRT or SRS compared to the published series on regular sized VS and other smaller retrospective studies on large VS.

  6. Radiation therapy for long-bone metastases

    International Nuclear Information System (INIS)

    Wadasaki, Kouichi; Tomiyoshi, Hideki; Ooshima, Yoshie; Urashima, Masaki; Mori, Masaki

    1992-01-01

    Efficacy of palliative and prophylactic radiotherapies for metastatic bone pain and pathological fracture was investigated in 14 patients with long bone metastases. Irradiation sites were the femur in 10 patients, the humerus in 2, the radius in one, and the tibia in one. Radiographs showed osteolytic lesion in 13 patients and osteoblastic lesion in one. A total dose of 48.6 Gy to 87.3 Gy was delivered in daily fractional doses of 2 Gy (one patient), 2.5 Gy (3), 3 Gy (6), 4 Gy (2) and 5 Gy (2), 5 days a week. For 13 patients, except for one death within one month after the completion of irradiation, pain relief was attained. Of these patients, 7 (54%) had complete pain relief. In one patient, pathological fracture occurred as early as 10 days after the beginning of irradiation when irradiation efficacy was not attained. In none of the 13 others, was pathological fracture encountered. No side effects were seen at all during or after irradiation. Radiation therapy was an extremely effective means for managing patients with long bone metastases in terms of its palliative and prophylactic role. (N.K.)

  7. The Indiana University proton radiation therapy project

    International Nuclear Information System (INIS)

    Bloch, C.; Derenchuk, V.; Cameron, J.; Fasano, M.; Gilmore, J.; Hashemian, R.; Hornback, N.; Low, D.A.; Morphis, J.; Peterson, C.; Rosselot, D.; Sandison, G.; Shen, R.N.; Shidnia, H.

    1993-01-01

    A fixed horizontal beam line at the Indiana University cyclotron facility (IUCF) has been equipped for proton radiation therapy treatment of head, neck, and brain tumors. The complete system will be commissioned and ready to treat patients early in 1993. IUCF can produce external proton beams from 45 to 200 MeV in energy, which corresponds to a maximum range in water of 26 cm. Beam currents over 100 nA are easily attained, allowing dose rates in excess of 200 cGy/min, even for large fields. Beam spreading systems have been tested which provide uniform fields up to 20 cm in diameter. Range modulation is accomplished with a rotating acrylic device, which provides uniform depth dose distributions from 3 to 18 cm in extent. Tests have been conducted on detectors which monitor the beam position and current, and the dose symmetry. This report discusses those devices, as well as the cyclotron characteristics, measured beam properties, safety interlocks, computerized dose delivery/monitoring system, and future plans. (orig.)

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

    Science.gov (United States)

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

    2006-01-01

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

  9. Safety and feasibility of STAT RAD: Improvement of a novel rapid tomotherapy-based radiation therapy workflow by failure mode and effects analysis.

    Science.gov (United States)

    Jones, Ryan T; Handsfield, Lydia; Read, Paul W; Wilson, David D; Van Ausdal, Ray; Schlesinger, David J; Siebers, Jeffrey V; Chen, Quan

    2015-01-01

    The clinical challenge of radiation therapy (RT) for painful bone metastases requires clinicians to consider both treatment efficacy and patient prognosis when selecting a radiation therapy regimen. The traditional RT workflow requires several weeks for common palliative RT schedules of 30 Gy in 10 fractions or 20 Gy in 5 fractions. At our institution, we have created a new RT workflow termed "STAT RAD" that allows clinicians to perform computed tomographic (CT) simulation, planning, and highly conformal single fraction treatment delivery within 2 hours. In this study, we evaluate the safety and feasibility of the STAT RAD workflow. A failure mode and effects analysis (FMEA) was performed on the STAT RAD workflow, including development of a process map, identification of potential failure modes, description of the cause and effect, temporal occurrence, and team member involvement in each failure mode, and examination of existing safety controls. A risk probability number (RPN) was calculated for each failure mode. As necessary, workflow adjustments were then made to safeguard failure modes of significant RPN values. After workflow alterations, RPN numbers were again recomputed. A total of 72 potential failure modes were identified in the pre-FMEA STAT RAD workflow, of which 22 met the RPN threshold for clinical significance. Workflow adjustments included the addition of a team member checklist, changing simulation from megavoltage CT to kilovoltage CT, alteration of patient-specific quality assurance testing, and allocating increased time for critical workflow steps. After these modifications, only 1 failure mode maintained RPN significance; patient motion after alignment or during treatment. Performing the FMEA for the STAT RAD workflow before clinical implementation has significantly strengthened the safety and feasibility of STAT RAD. The FMEA proved a valuable evaluation tool, identifying potential problem areas so that we could create a safer workflow

  10. Long-term Results of Carbon Ion Radiation Therapy for Locally Advanced or Unfavorably Located Choroidal Melanoma: Usefulness of CT-based 2-Port Orthogonal Therapy for Reducing the Incidence of Neovascular Glaucoma

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, Shingo [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Department of Heavy Particle Therapy and Radiation Oncology, Faculty of Medicine, Saga University, Saga (Japan); Tsuji, Hiroshi, E-mail: h_tsuji@nirs.go.jp [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Mizoguchi, Nobutaka; Nomiya, Takuma; Kamada, Tadashi [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Tokumaru, Sunao [Department of Heavy Particle Therapy and Radiation Oncology, Faculty of Medicine, Saga University, Saga (Japan); Mizota, Atsushi [Department of Ophthalmology, Teikyo University School of Medicine, Tokyo (Japan); Ohnishi, Yoshitaka [Department of Ophthalmology, Wakayama Medical University, Wakayama (Japan); Tsujii, Hirohiko [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan)

    2013-06-01

    Purpose: To determine the long-term results of carbon ion radiation therapy (C-ion RT) in patients with choroidal melanoma, and to assess the usefulness of CT-based 2-port irradiation in reducing the risk of neovascular glaucoma (NVG). Methods and Materials: Between January 2001 and February 2012, a total of 116 patients with locally advanced or unfavorably located choroidal melanoma received CT-based C-ion RT. Of these patients, 114 were followed up for more than 6 months and their data analyzed. The numbers of T3 and T2 patients (International Union Against Cancer [UICC], 5th edition) were 106 and 8, respectively. The total dose of C-ion RT varied from 60 to 85 GyE, with each dose given in 5 fractions. Since October 2005, 2-port therapy (51 patients) has been used in an attempt to reduce the risk of NVG. A dose-volume histogram analysis was also performed in 106 patients. Results: The median follow-up was 4.6 years (range, 0.5-10.6 years). The 5-year overall survival, cause-specific survival, local control, distant metastasis-free survival, and eye retention rates were 80.4% (95% confidence interval 89.0%-71.8%), 82.2% (90.6%-73.8%), 92.8% (98.5%-87.1%), 72.1% (81.9%-62.3%), and 92.8% (98.1%-87.5%), respectively. The overall 5-year NVG incidence rate was 35.9% (25.9%-45.9%) and that of 1-port group and 2-port group were 41.6% (29.3%-54.0%) and 13.9% (3.2%-24.6%) with statistically significant difference (P<.001). The dose-volume histogram analysis showed that the average irradiated volume of the iris-ciliary body was significantly lower in the non-NVG group than in the NVG group at all dose levels, and significantly lower in the 2-port group than in the 1-port group at high dose levels. Conclusions: The long-term results of C-ion RT for choroidal melanoma are satisfactory. CT-based 2-port C-ion RT can be used to reduce the high-dose irradiated volume of the iris-ciliary body and the resulting risk of NVG.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  12. Chondronecrosis of the cricoid cartilage following radiation therapy

    International Nuclear Information System (INIS)

    Tanabe, Masahiro; Isshiki, Nobuhiko; Kojima, Hisayoshi

    1979-01-01

    Chondronecrosis of the laryngeal cartilage following radiation therapy is a rare but serious complication. We report herein a case of post-radiation chondronecrosis and discuss factors predisposing to its development. A 67-year-old man received telecobalt therapy for cancer of the right vocal cord. A year after the radiation therapy given in a dose of 7,000r, the patient developed dysphagia and dyspnea. Following tracheotomy, he underwent total laryngectomy. The surgical specimen showed no cancer but chondronecrosis of the cricoid cartilage was present. After laryngectomy he developed progressive soft tissue necrosis of the neck and died following a carotid hemorrhage. (author)

  13. Radiation therapy quality control in MRCCC radiotherapy units

    International Nuclear Information System (INIS)

    Fielda Djuita; Rina Taurisia; Andreas Nainggolan

    2011-01-01

    Increasing cancer patients in Indonesia is not supported with the number of equipment that is able to treat cancer patients, especially in the radiation therapy field. Therefore, several private hospitals have joined to provide radiation therapy services and one of them is MRCCC. As a new hospital providing services in radiotherapy field, the writer tries to present our quality control program that we have done in our hospital. Purpose: As quality control to radiation therapy clinical practice. Methods: Descriptive essay of what we do in our institution. Conclusion: Average output photon and electron lower more than tolerance dose. (author)

  14. Optimizing patient positioning for intensity modulated radiation therapy in hippocampal-sparing whole brain radiation therapy.

    Science.gov (United States)

    Siglin, Joshua; Champ, Colin E; Vakhnenko, Yelena; Witek, Matthew E; Peng, Cheng; Zaorsky, Nicholas G; Harrison, Amy S; Shi, Wenyin

    2014-01-01

    Sparing the hippocampus during whole brain radiation therapy (WBRT) offers potential neurocognitive benefits. However, previously reported intensity modulated radiation therapy (IMRT) plans use multiple noncoplanar beams for treatment delivery. An optimized coplanar IMRT template for hippocampal-sparing WBRT would assist in clinical workflow and minimize resource utilization. In this study, we sought to determine the optimal patient position to facilitate coplanar treatment planning and delivery of hippocampal-sparing WBRT using IMRT. A variable angle, inclined board was utilized for patient positioning. An anthropomorphic phantom underwent computed tomography simulation at various head angles. The IMRT goals were designed to achieve target coverage of the brain while maintaining hippocampal dose-volume constraints designed to conform to the Radiation Therapy Oncology Group 0933 protocol. Optimal head angle was then verified using data from 8 patients comparing coplanar and noncoplanar WBRT IMRT plans. Hippocampal, hippocampal avoidance region, and whole brain mean volumes were 1.1 cm(3), 12.5 cm(3), and 1185.1 cm(3), respectively. The hippocampal avoidance region occupied 1.1% of the whole brain planning volume. For the 30-degree head angle, a 7-field coplanar IMRT plan was generated, sparing the hippocampus to a maximum dose of 14.7 Gy; D100% of the hippocampus was 7.4 Gy and mean hippocampal dose was 9.3 Gy. In comparison, for flat head positioning the hippocampal Dmax was 22.9 Gy with a D100% of 9.2 Gy and mean dose of 11.7 Gy. Target coverage and dose homogeneity was comparable with previously published noncoplanar IMRT plans. Compared with conventional supine positioning, an inclined head board at 30 degrees optimizes coplanar whole brain IMRT treatment planning. Clinically acceptable hippocampal-sparing WBRT dosimetry can be obtained using a simplified coplanar plan at a 30-degree head angle, thus obviating the need for complex and time consuming noncoplanar

  15. Approach of combined cancer gene therapy and radiation: response of promoters to ionizing radiation

    International Nuclear Information System (INIS)

    Anstett, A.

    2005-09-01

    Gene therapy is an emerging cancer treatment modality. We are interested in developing a radiation-inducible gene therapy system to sensitize the tumor vasculature to the effects of ionizing radiation (IR) treatment. An expression system based on irradiation-inducible promoters will drive the expression of anti-tumor genes in the tumor vasculature. Solid tumors are dependent on angio genesis, a process in which new blood vessels are formed from the pre-existing vasculature. Vascular endothelial cells are un transformed and genetically stable, thus avoiding the problem of resistance to the treatments. Vascular endothelial cells may therefore represent a suitable target for this therapeutic gene therapy strategy.The identification of IR-inducible promoters native to endothelial cells was performed by gene expression profiling using cDNA micro array technology. We describe the genes modified by clinically relevant doses of IR. The extension to high doses aimed at studying the effects of total radiation delivery to the tumor. The radio-inductiveness of the genes selected for promoter study was confirmed by RT-PCR. Analysis of the activity of promoters in response to IR was also assessed in a reporter plasmid. We found that authentic promoters cloned onto a plasmid are not suitable for cancer gene therapy due to their low induction after IR. In contrast, synthetic promoters containing repeated sequence-specific binding sites for IR-activated transcription factors such as NF-κB are potential candidates for gene therapy. The activity of five tandemly repeated TGGGGACTTTCCGC elements for NF-κB binding in a luciferase reporter was increased in a dose-dependent manner. Interestingly, the response to fractionated low doses was improved in comparison to the total single dose. Thus, we put present evidence that a synthetic promoter for NF-κB specific binding may have application in the radio-therapeutic treatment of cancer. (author)

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

    Science.gov (United States)

    Amols, Howard I

    2008-11-01

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