High energy radiation from neutron stars

International Nuclear Information System (INIS)

Ruderman, M.

1985-04-01

Topics covered include young rapidly spinning pulsars; static gaps in outer magnetospheres; dynamic gaps in pulsar outer magnetospheres; pulse structure of energetic radiation sustained by outer gap pair production; outer gap radiation, Crab pulsar; outer gap radiation, the Vela pulsar; radioemission; and high energy radiation during the accretion spin-up of older neutron stars. 26 refs., 10 figs

Radiation monitoring in high energy research facility

International Nuclear Information System (INIS)

Miyajima, Mitsuhiro

1975-01-01

In High Energy Physics Research Laboratory, construction of high energy proton accelerator is in progress. The accelerator is a cascaded machine comprising Cockcroft type (50 keV), linac (20 MeV), booster synchrotron (500 MeV), and synchrotron (8-12 GeV). Its proton beam intensity is 1x10 13 photons/pulse, and acceleration is carried out at the rate of every 2 minutes. The essential problems of radiation control in high energy accelerators are those of various radiations generated secondarily by proton beam and a number of induced radiations simultaneously originated with such secondary particles. In the Laboratory, controlled areas are divided into color-coded four regions, red, orange, yellow and green, based on each dose-rate. BF 3 counters covered with thick paraffin are used as neutron detectors, and side-window GM tubes, NaI (Tl) scintillators and ionization chambers as γ-detectors. In red region, however, ionization chambers are applied to induced radiation detection, and neutrons are not monitored. NIM standards are adopted for the circuits of all above monitors considering easy maintenance, economy and interchangeability. Notwithstanding the above described systems, these monitors are not sufficient to complete the measurement of whole radiations over wide energy region radiated from the accelerators. Hence separate radiation field measurement is required periodically. An example of the monitoring systems in National Accelerator Laboratory (U.S.) is referred at the last section. (Wakatsuki, Y.)

Dose measurement techniques for high-energy photon and electron radiation

International Nuclear Information System (INIS)

Hohlfeld, K.; Roos, M.

1992-08-01

By law the Federal Institute of Physics and Technology (PTB) has been assigned the tasks of representing, preserving and passing on dose units. The analogous continuation of these tasks consists in improving, at the user level, dosimetry techniques in radiation therapy for the benefit of patients. The PTB had an essential share in working out the scientific foundations of dosimetry for high-energy radiation, and the corresponding DIN standards were established with the PTB playing a prominent part. The seminar aimed at presenting the measuring techniques fixed in the new DIN standard 6800 part 2 'Dose measurement techniques according to the probe method - ionization dosimetry', to discuss their physical background and practical implications resulting from them. (orig.) [de

WE-A-BRF-01: Dual-Energy CT Imaging in Diagnostic Imaging and Radiation Therapy

International Nuclear Information System (INIS)

Molloi, S; Li, B; Yin, F; Chen, H

2014-01-01

classification based on calcium scores shows excellent agreement with classification on the basis of conventional coronary artery calcium scoring. These studies demonstrate dual-energy cardiovascular CT can potentially be a noninvasive and sensitive modality in high risk patients. On-board KV/MV Imaging. To enhance soft tissue contrast and reduce metal artifacts, we have developed a dual-energy CBCT technique and a novel on-board kV/MV imaging technique based on hardware available on modern linear accelerators. We have also evaluated the feasibility of these two techniques in various phantom studies. Optimal techniques (energy, beam filtration, # of overlapping projections, etc) have been investigated with unique calibration procedures, which leads to successful decomposition of imaged material into acrylic-aluminum basis material pair. This enables the synthesis of virtual monochromatic (VM) CBCT images that demonstrate much less beam hardening, significantly reduced metal artifacts, and/or higher soft tissue CNR compared to single-energy CBCT. Adaptive Radiation Therapy. DECT could actually contribute to the area of Dose-Guided Radiation Therapy (or Adaptive Therapy). The application of DECT imaging using 80kV and 140 kV combinations could potentially increase the image quality by reducing the bone or high density material artifacts and also increase the soft tissue contrast by a light contrast agent. The result of this higher contrast / quality images is beneficial for deformable image registration / segmentation algorithm to improve its accuracy hence to make adaptive therapy less time consuming in its recontouring process. The real time re-planning prior to per treatment fraction could become more realistic with this improvement especially in hypofractional SBRT cases. Learning Objectives: Learn recent developments of dual-energy imaging in diagnosis and radiation therapy; Understand the unique clinical problem and required quantification accuracy in each application

Radiosensitization of high-Z compounds by medium-energy 160 kV vs. high-energy 6 MV X-rays for radiation therapy: Theoretical, in vitro and in vivo studies of platinum compounds activating glioma F98 cancer cells

Science.gov (United States)

Lim, S.; Pradhan, A.; Nahar, S.; Montenegro, M.; Barth, R.; Nakkula, R.; Turro, C.

2013-03-01

Energy dependence of X-ray irradiation of high-Z compounds for enhanced radiosensitization is explored thoeretically and via in vitro and in vivo experiments. The cell killing ability of medium-energy X-rays from 160 kV source are found to be more effective than 6 MV X-rays in activating high-Z contrast agents. Results are presented for a newly synthesized Pt compound, Pyridine Terpyridine Pt(II) Nitrate ([Pt(typ)(py)]) and carboplatin in treating F98 rat glioma. In-vitro results show considerable reduction in cell viability for radiosensitized cells irradiated with a 160 kV irradiator. Cells treated with 6 MV LINAC radiation find little variation with radiation dose. Maximum dose enhancement factors (DEFs) and minimum cancer cell survival fractions correspond to 50-200 keV range, and fall rapidly at higher energies. Theoretical calculations of photoelectric absorption vis-a-vis total scattering demonstrates this energy dependence. However, in vivo studies of rats treated with [Pt(tpy)(py)] had a severe negative neurotoxic response, confirmed by histopathological analysis. But subsequent in vivo studies using carboplatin showed very positive results in the treatment of F98 glioma bearing rats and potential clinical radiation therapy.

Quasi-VMAT in high-grade glioma radiation therapy

International Nuclear Information System (INIS)

Fadda, G.; Massazza, G.; Zucca, S.; Durzu, S.; Meleddu, G.; Possanzini, M.; Farace, P.

2013-01-01

Purpose: To compare a quasi-volumetric modulated arc therapy (qVMAT) with three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) for the treatment of high-grade gliomas. The qVMAT technique is a fast method of radiation therapy in which multiple equispaced beams analogous to those in rotation therapy are radiated in succession. Patients and methods: This study included 12 patients with a planning target volume (PTV) that overlapped at least one organ at risk (OAR). 3D-CRT was planned using 2-3 non-coplanar beams, whereby the field-in-field technique (FIF) was used to divide each field into 1-3 subfields to shield the OAR. The qVMAT strategy was planned with 15 equispaced beams and IMRT was planned using 9 beams with a total of 80 segments. Inverse planning for qVMAT and IMRT was performed by direct machine parameter optimization (DMPO) to deliver a homogenous dose distribution of 60 Gy within the PTV and simultaneously limit the dose received by the OARs to the recommended values. Finally, the effect of introducing a maximum dose objective (max. dose 95% and conformity index (CI) values in comparison to 3D-CRT (PTV 95% = 90.7 % vs. 82.0 %; CI = 0.79 vs. 0.74, respectively). A further improvement was achieved by IMRT (PTV 95% = 94.4 %, CI = 0.78). In qVMAT and IMRT, the addition of a 0.5 cm ring around the PTV produced a significant increase in CI (0.87 and 0.88, respectively), but dosage homogeneity within the PTV was considerably reduced (PTV 95% = 88.5 % and 92.3 %, respectively). The time required for qVMAT dose delivery was similar to that required using 3D-CRT. Conclusion: These findings suggest that qVMAT should be preferred to 3D-CRT for the treatment of high-grade gliomas. The qVMAT method could be applied in hospitals, for example, which have limited departmental resources and are not equipped with systems capable of VMAT delivery. (orig.)

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 ...

Paradigm Shift in Radiation Biology/Radiation Oncology-Exploitation of the "H₂O₂ Effect" for Radiotherapy Using Low-LET (Linear Energy Transfer) Radiation such as X-rays and High-Energy Electrons.

Science.gov (United States)

Ogawa, Yasuhiro

2016-02-25

Most radiation biologists/radiation oncologists have long accepted the concept that the biologic effects of radiation principally involve damage to deoxyribonucleic acid (DNA), which is the critical target, as described in "Radiobiology for the Radiologist", by E.J. Hall and A.J. Giaccia [1]. Although the concepts of direct and indirect effects of radiation are fully applicable to low-LET (linear energy transfer) radioresistant tumor cells/normal tissues such as osteosarcoma cells and chondrocytes, it is believed that radiation-associated damage to DNA does not play a major role in the mechanism of cell death in low-LET radiosensitive tumors/normal tissues such as malignant lymphoma cells and lymphocytes. Hall and Giaccia describe lymphocytes as very radiosensitive, based largely on apoptosis subsequent to irradiation. As described in this review, apoptosis of lymphocytes and lymphoma cells is actually induced by the "hydrogen peroxide (H₂O₂) effect", which I propose in this review article for the first time. The mechanism of lymphocyte death via the H₂O₂ effect represents an ideal model to develop the enhancement method of radiosensitivity for radiation therapy of malignant neoplasms. In terms of imitating the high radiosensitivity of lymphocytes, osteosarcoma cells (representative of low-LET radioresistant cells) might be the ideal model for indicating the conversion of cells from radioresistant to radiosensitive utilizing the H₂O₂ effect. External beam radiation such as X-rays and high-energy electrons for use in modern radiotherapy are generally produced using a linear accelerator. We theorized that when tumors are irradiated in the presence of H₂O₂, the activities of anti-oxidative enzymes such as peroxidases and catalase are blocked and oxygen molecules are produced at the same time via the H₂O₂ effect, resulting in oxidative damage to low-LET radioresistant tumor cells, thereby rendering them highly sensitive to irradiation. In this

High energy radiation effects on the human body

International Nuclear Information System (INIS)

Kato, Kazuaki

1977-01-01

High-energy radiation injuries and their risks were recognized, information on low-energy radiation injuries was also arranged, and with these backgrounds, countermeasures against prevention of radiation injuries were considered. Redintegration of DNA and mutation by radiation were described, and relationship between radiation injuries and dose was considered. Interaction of high-energy radiation and substances in the living body and injuries by the interaction were also considered. Expression method of risk was considered, and a concept of protection dose was suggested. Protection dose is dose equivalent which is worthy of value at the point where the ratio to permissible dose distributed among each part of the body is at its maximum in the distribution of dose equivalent formed within the body when standard human body is placed at a certain radiation field for a certain time. Significance and countermeasures of health examination which is under an abligation to make radiation workers receive health check were thought, and problems were proposed on compensation when radiation injuries should appear actually. (Tsunoda, M.)

The Clatterbridge high-energy neutron therapy facility: specification and performance

International Nuclear Information System (INIS)

Bonnett, D.E.; Blake, S.W.; Shaw, J.E.; Bewley, D.K.

1988-01-01

A high energy neutron therapy facility has been installed at the Douglas Cyclotron Centre, Clatterbridge Hospital Merseyside, to extend M.R.C. clinical trials of fast neutrons. The neutron beam is produced by bombarding a beryllium target with 62 MeV protons. The target is isocentrically mounted with potential for 360 0 rotation, with a fully variable collimator, giving a range of rectilinear field sizes from 5 cm x 5 cm to 30 cm x 30 cm. Basic neutron beam data including output, field flatness, penumbra and depth-dose data have been measured. For a 10 cm x 10 cm field, 50% depth dose occurs at 16.2 cm in water and output is 1.63 cGy μ A -1 min -1 at maximum dose depth. Effectiveness of the target shielding and neutron-induced radioactivity in the treatment head were also measured. It is concluded that the equipment meets design specifications and fully satisfies criticisms of earlier neutron therapy equipment. A full radiation survey showed that radiation levels present no significant staff hazard. (UK)

Quasi-VMAT in high-grade glioma radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Fadda, G.; Massazza, G.; Zucca, S.; Durzu, S.; Meleddu, G.; Possanzini, M.; Farace, P. [Regional Oncological Hospital, Cagliari (Italy). Dept. of Radio-Oncology

2013-05-15

Purpose: To compare a quasi-volumetric modulated arc therapy (qVMAT) with three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) for the treatment of high-grade gliomas. The qVMAT technique is a fast method of radiation therapy in which multiple equispaced beams analogous to those in rotation therapy are radiated in succession. Patients and methods: This study included 12 patients with a planning target volume (PTV) that overlapped at least one organ at risk (OAR). 3D-CRT was planned using 2-3 non-coplanar beams, whereby the field-in-field technique (FIF) was used to divide each field into 1-3 subfields to shield the OAR. The qVMAT strategy was planned with 15 equispaced beams and IMRT was planned using 9 beams with a total of 80 segments. Inverse planning for qVMAT and IMRT was performed by direct machine parameter optimization (DMPO) to deliver a homogenous dose distribution of 60 Gy within the PTV and simultaneously limit the dose received by the OARs to the recommended values. Finally, the effect of introducing a maximum dose objective (max. dose < 54 Gy) for a virtual OAR in the form of a 0.5 cm ring around the PTV was investigated. Results: The qVMAT method gave rise to significantly improved PTV{sub 95%} and conformity index (CI) values in comparison to 3D-CRT (PTV{sub 95%} = 90.7 % vs. 82.0 %; CI = 0.79 vs. 0.74, respectively). A further improvement was achieved by IMRT (PTV{sub 95%} = 94.4 %, CI = 0.78). In qVMAT and IMRT, the addition of a 0.5 cm ring around the PTV produced a significant increase in CI (0.87 and 0.88, respectively), but dosage homogeneity within the PTV was considerably reduced (PTV{sub 95%} = 88.5 % and 92.3 %, respectively). The time required for qVMAT dose delivery was similar to that required using 3D-CRT. Conclusion: These findings suggest that qVMAT should be preferred to 3D-CRT for the treatment of high-grade gliomas. The qVMAT method could be applied in hospitals, for example

Low and high linear energy transfer radiation sensitization of HCC cells by metformin

International Nuclear Information System (INIS)

Kim, Eun Ho; Jung, Won-Gyun; Kim, Mi-Sook; Cho, Chul-Koo; Jeong, Youn Kyoung; Jeong, Jae-Hoon

2014-01-01

The purpose of this study was to investigate the efficacy of metformin as a radiosensitizer for use in combination therapy for human hepatocellular carcinoma (HCC). Three human HCC cell lines (Huh7, HepG2, Hep3B) and a normal human hepatocyte cell line were treated with metformin alone or with radiation followed by metformin. In vitro tests were evaluated by clonogenic survival assay, FACS analysis, western blotting, immunofluorescence and comet assay. Metformin significantly enhanced radiation efficacy under high and low Linear Energy Transfer (LET) radiation conditions in vitro. In combination with radiation, metformin abrogated G2/M arrest and increased the cell population in the sub-G1 phase and the ROS level, ultimately increasing HCC cellular apoptosis. Metformin inhibits the repair of DNA damage caused by radiation. The radiosensitizing effects of metformin are much higher in neutron (high LET)-irradiated cell lines than in γ (low LET)-irradiated cell lines. Metformin only had a moderate effect in normal hepatocytes. Metformin enhances the radiosensitivity of HCC, suggesting it may have clinical utility in combination cancer treatment with high-LET radiation. (author)

Semiconductor high-energy radiation scintillation detector

International Nuclear Information System (INIS)

Kastalsky, A.; Luryi, S.; Spivak, B.

2006-01-01

We propose a new scintillation-type detector in which high-energy radiation generates electron-hole pairs in a direct-gap semiconductor material that subsequently recombine producing infrared light to be registered by a photo-detector. The key issue is how to make the semiconductor essentially transparent to its own infrared light, so that photons generated deep inside the semiconductor could reach its surface without tangible attenuation. We discuss two ways to accomplish this, one based on doping the semiconductor with shallow impurities of one polarity type, preferably donors, the other by heterostructure bandgap engineering. The proposed semiconductor scintillator combines the best properties of currently existing radiation detectors and can be used for both simple radiation monitoring, like a Geiger counter, and for high-resolution spectrography of the high-energy radiation. An important advantage of the proposed detector is its fast response time, about 1 ns, essentially limited only by the recombination time of minority carriers. Notably, the fast response comes without any degradation in brightness. When the scintillator is implemented in a qualified semiconductor material (such as InP or GaAs), the photo-detector and associated circuits can be epitaxially integrated on the scintillator slab and the structure can be stacked-up to achieve virtually any desired absorption capability

Radiographic imaging system for high energy radiation

International Nuclear Information System (INIS)

Barrett, H.H.

1976-01-01

A radiographic imaging system for high energy radiation utilizing a detector of such radiation and a mask having regions relatively transparent to such radiation interspersed among regions relatively opaque to such radiation is described. A relative motion is imparted between the mask and the detector, the detector providing a time varying signal in response to the incident radiation and in response to the relative motion. The time varying signal provides, with the aid of a decoder, an image of a source of such radiation

Radiographic imaging system for high energy radiation

International Nuclear Information System (INIS)

1975-01-01

A radiographic imaging system for high energy radiation is described utilizing a detector of such radiation and a mask having regions relatively transparent to such radiation and interspersed among regions relatively opaque to such radiation. A relative motion is imparted between the mask and the detector, the detector providing a time varying signal in response to the incident radiation and in response to the relative motion. The time varying signal provides, with the aid of a decoder, an image of a source of such radiation

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

International Nuclear Information System (INIS)

Kun, Larry E.; Beltran, Chris

2009-01-01

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

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)

Quasi-VMAT in high-grade glioma radiation therapy.

Science.gov (United States)

Fadda, G; Massazza, G; Zucca, S; Durzu, S; Meleddu, G; Possanzini, M; Farace, P

2013-05-01

To compare a quasi-volumetric modulated arc therapy (qVMAT) with three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) for the treatment of high-grade gliomas. The qVMAT technique is a fast method of radiation therapy in which multiple equispaced beams analogous to those in rotation therapy are radiated in succession. This study included 12 patients with a planning target volume (PTV) that overlapped at least one organ at risk (OAR). 3D-CRT was planned using 2-3 non-coplanar beams, whereby the field-in-field technique (FIF) was used to divide each field into 1-3 subfields to shield the OAR. The qVMAT strategy was planned with 15 equispaced beams and IMRT was planned using 9 beams with a total of 80 segments. Inverse planning for qVMAT and IMRT was performed by direct machine parameter optimization (DMPO) to deliver a homogenous dose distribution of 60 Gy within the PTV and simultaneously limit the dose received by the OARs to the recommended values. Finally, the effect of introducing a maximum dose objective (max. dose < 54 Gy) for a virtual OAR in the form of a 0.5 cm ring around the PTV was investigated. The qVMAT method gave rise to significantly improved PTV95% and conformity index (CI) values in comparison to 3D-CRT (PTV95% = 90.7 % vs. 82.0 %; CI = 0.79 vs. 0.74, respectively). A further improvement was achieved by IMRT (PTV95% = 94.4 %, CI = 0.78). In qVMAT and IMRT, the addition of a 0.5 cm ring around the PTV produced a significant increase in CI (0.87 and 0.88, respectively), but dosage homogeneity within the PTV was considerably reduced (PTV95% = 88.5 % and 92.3 %, respectively). The time required for qVMAT dose delivery was similar to that required using 3D-CRT. These findings suggest that qVMAT should be preferred to 3D-CRT for the treatment of high-grade gliomas. The qVMAT method could be applied in hospitals, for example, which have limited departmental

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)

Radiation processing with high-energy X-rays

International Nuclear Information System (INIS)

Cleland, Marshall R.; Stichelbaut, Frederic

2009-01-01

The physical, chemical or biological characteristics of selected commercial products and materials can be improved by radiation processing. The ionizing energy can be provided by accelerated electrons with energies between 75 keV and 10 MeV, gamma rays from cobalt-60 with average energies of 1.25 MeV or X-rays with maximum energies up to 7.5 MeV. Electron beams are preferred for thin products, which are processed at high speeds. Gamma rays are used for products that are too thick for treatment with electron beams. High-energy X-rays can also be used for these purposes because their penetration in solid materials is similar to or even slightly greater than that of gamma rays. Previously, the use of X-rays had been inhibited by their slower processing rates and higher costs when compared with gamma rays. Since then, the price of cobalt-60 sources has been increased and the radiation intensity from high-energy, high-power X-ray generators has also increased. For facilities requiring at least 2 MCi of cobalt-60, the capital and operating costs of X-ray facilities with equivalent processing rates can be less than that of gamma-ray irradiators. Several high-energy electron beam facilities have been equipped with removable X-ray targets so that irradiation processes can be done with either type of ionizing energy. A new facility is now being built which will be used exclusively in the X-ray mode to sterilize medical products. Operation of this facility will show that high-energy, high-power X-ray generators are practical alternatives to large gamma-ray sources. (author)

Improved Survival With Radiation Therapy in High-Grade Soft Tissue Sarcomas of the Extremities: A SEER Analysis

International Nuclear Information System (INIS)

Koshy, Matthew; Rich, Shayna E.; Mohiuddin, Majid M.

2010-01-01

Purpose: The benefit of radiation therapy in extremity soft tissue sarcomas remains controversial. The purpose of this study was to determine the effect of radiation therapy on overall survival among patients with primary soft tissue sarcomas of the extremity who underwent limb-sparing surgery. Methods and Materials: A retrospective study from the Surveillance, Epidemiology, and End Results (SEER) database that included data from January 1, 1988, to December 31, 2005. A total of 6,960 patients constituted the study population. Overall survival curves were constructed using the Kaplan-Meir method and for patients with low- and high-grade tumors. Hazard ratios were calculated based on multivariable Cox proportional hazards models. Results: Of the cohort, 47% received radiation therapy. There was no significant difference in overall survival among patients with low-grade tumors by radiation therapy. In high-grade tumors, the 3-year overall survival was 73% in patients who received radiation therapy vs. 63% for those who did not receive radiation therapy (p < 0.001). On multivariate analysis, patients with high-grade tumors who received radiation therapy had an improved overall survival (hazard ratio 0.67, 95% confidence interval 0.57-0.79). In patients receiving radiation therapy, 13.5% received it in a neoadjuvant setting. The incidence of patients receiving neoadjuvant radiation did not change significantly between 1988 and 2005. Conclusions: To our knowledge, this is the largest population-based study reported in patients undergoing limb-sparing surgery for soft tissue sarcomas of the extremities. It reports that radiation was associated with improved survival in patients with high-grade tumors.

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

Challenge of high energy radiation dosimetry and protection

International Nuclear Information System (INIS)

Nelson, W.R.; Jenkins, T.M.

1976-08-01

An accelerator health physicist can make contributions in many fields of science in addition to the various operational tasks that he is charged with. He can support others in his laboratory by designing shielding for new accelerators and storage rings, by consulting with experimenters on background radiation problems that they may encounter, by helping the high energy physicist select appropriate radiation sources for checking out his equipment, by providing him with low energy atomic and nuclear physics calculations, and many other ways. Most of all, he can perform and publish research using the many tools and techniques that are at his disposal at a high-energy accelerator laboratory

High-energy outer radiation belt dynamic modeling

International Nuclear Information System (INIS)

Chiu, Y.T.; Nightingale, R.W.; Rinaldi, M.A.

1989-01-01

Specification of the average high-energy radiation belt environment in terms of phenomenological montages of satellite measurements has been available for some time. However, for many reasons both scientific and applicational (including concerns for a better understanding of the high-energy radiatino background in space), it is desirable to model the dynamic response of the high-energy radiation belts to sources, to losses, and to geomagnetic activity. Indeed, in the outer electron belt, this is the only mode of modeling that can handle the large intensity fluctuations. Anticipating the dynamic modeling objective of the upcoming Combined Release and Radiation Effects Satellite (CRRES) program, we have undertaken to initiate the study of the various essential elements in constructing a dynamic radiation belt model based on interpretation of satellite data according to simultaneous radial and pitch-angle diffusion theory. In order to prepare for the dynamic radiation belt modeling based on a large data set spanning a relatively large segment of L-values, such as required for CRRES, it is important to study a number of test cases with data of similar characteristics but more restricted in space-time coverage. In this way, models of increasing comprehensiveness can be built up from the experience of elucidating the dynamics of more restrictive data sets. The principal objectives of this paper are to discuss issues concerning dynamic modeling in general and to summarize in particular the good results of an initial attempt at constructing the dynamics of the outer electron radiation belt based on a moderately active data period from Lockheed's SC-3 instrument flown on board the SCATHA (P78-2) spacecraft. Further, we shall discuss the issues brought out and lessons learned in this test case

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)

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)

Radiation safety aspects of high energy particle accelerators

International Nuclear Information System (INIS)

Subbaiah, K.V.

2007-01-01

High-energy accelerators are widely used for various applications in industry, medicine and research. These accelerators are capable of accelerating both ions and electrons over a wide range of energy and subsequently are made to impinge on the target materials. Apart from generating intended reactions in the target, these projectiles can also generate highly penetrating radiations such as gamma rays and neutrons. Over exposure to these radiations will cause deleterious effects on the living beings. Various steps taken to protect workers and general public from these harmful radiations is called radiation safety. The primary objective in establishing permissible values for occupational workers is to keep the radiation worker well below a level at which adverse effects are likely to be observed during one's life time. Another objective is to minimize the incidence of genetic effects for the population as a whole. Today's presentation on radiation safety of accelerators will touch up on the following sub-topics: Types of particle accelerators and their applications; AERB directives on dose limits; Radiation Source term of accelerators; Shielding Design-Use of Transmission curves and Tenth Value layers; Challenges for accelerator health physicists

Paradigm Shift in Radiation Biology/Radiation Oncology—Exploitation of the “H2O2 Effect” for Radiotherapy Using Low-LET (Linear Energy Transfer Radiation such as X-rays and High-Energy Electrons

Directory of Open Access Journals (Sweden)

Yasuhiro Ogawa

2016-02-01

Full Text Available Most radiation biologists/radiation oncologists have long accepted the concept that the biologic effects of radiation principally involve damage to deoxyribonucleic acid (DNA, which is the critical target, as described in “Radiobiology for the Radiologist”, by E.J. Hall and A.J. Giaccia [1]. Although the concepts of direct and indirect effects of radiation are fully applicable to low-LET (linear energy transfer radioresistant tumor cells/normal tissues such as osteosarcoma cells and chondrocytes, it is believed that radiation-associated damage to DNA does not play a major role in the mechanism of cell death in low-LET radiosensitive tumors/normal tissues such as malignant lymphoma cells and lymphocytes. Hall and Giaccia describe lymphocytes as very radiosensitive, based largely on apoptosis subsequent to irradiation. As described in this review, apoptosis of lymphocytes and lymphoma cells is actually induced by the “hydrogen peroxide (H2O2 effect”, which I propose in this review article for the first time. The mechanism of lymphocyte death via the H2O2 effect represents an ideal model to develop the enhancement method of radiosensitivity for radiation therapy of malignant neoplasms. In terms of imitating the high radiosensitivity of lymphocytes, osteosarcoma cells (representative of low-LET radioresistant cells might be the ideal model for indicating the conversion of cells from radioresistant to radiosensitive utilizing the H2O2 effect. External beam radiation such as X-rays and high-energy electrons for use in modern radiotherapy are generally produced using a linear accelerator. We theorized that when tumors are irradiated in the presence of H2O2, the activities of anti-oxidative enzymes such as peroxidases and catalase are blocked and oxygen molecules are produced at the same time via the H2O2 effect, resulting in oxidative damage to low-LET radioresistant tumor cells, thereby rendering them highly sensitive to irradiation. In this

Radiation Therapy for Cancer

Science.gov (United States)

Radiation therapy is a type of cancer treatment that uses high doses of radiation to kill cancer cells and shrink tumors. Learn about the types of radiation, why side effects happen, which ones you might have, and more.

Combined adjuvant radiation and interferon-alpha 2B therapy in high-risk melanoma patients: the potential for increased radiation toxicity

International Nuclear Information System (INIS)

Hazard, Lisa J.; Sause, William T.; Noyes, R. Dirk

2002-01-01

Purpose: Surgically resected melanoma patients with high-risk features commonly receive adjuvant therapy with interferon-alpha 2b combined with radiation therapy; the purpose of our study was to evaluate the potential enhancement of radiation toxicity by interferon. Methods and Materials: Patients at LDS Hospital and the University of Utah Medical Center in Salt Lake City treated with interferon during radiotherapy or within 1 month of its completion were retrospectively identified, and their charts were reviewed. If possible, the patients were asked to return to the LDS Hospital radiation therapy department for follow-up. Results: Five of 10 patients receiving interferon-alpha 2b therapy during radiation therapy or within 1 month of its completion experienced severe subacute/late complications of therapy. Severe subacute/late complications included two patients with peripheral neuropathy, one patient with radiation necrosis in the brain, and two patients with radiation necrosis in the s.c. tissue. One patient with peripheral neuropathy and one patient with radiation necrosis also developed lymphedema. Conclusions: In vitro studies have identified a radiosensitizing effect by interferon-alpha on certain cell lines, which suggests the possibility that patients treated with interferon and radiation therapy may experience more severe radiation toxicities. We have observed severe subacute/late complications in five of 10 patients treated with interferon-alpha 2b during radiation therapy or within 1 month of its completion. Although an observational study of 10 patients lacks the statistic power to reach conclusions regarding the safety and complication rates of combined interferon and radiation therapy, it is sufficient to raise concerns and suggest the need for prospective studies

Physics of intense, high energy radiation effects

International Nuclear Information System (INIS)

Hjalmarson, Harold Paul; Hartman, E. Frederick; Magyar, Rudolph J.; Crozier, Paul Stewart

2011-01-01

This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic calculations, the

High-energy X-ray detection using organic luminescent materials: a novel application for radiation therapy

International Nuclear Information System (INIS)

Schimitberger, Thiago; Ferreira, Giovana Ribeiro; Silva, Mariana de Melo; Saraiva, M.F.; Bianchi, Rodrigo Fernando

2010-01-01

In this work, it is presented the characterization and fabrication of a novel ionizing radiation sensor for high energy X-ray (6 MeV). It is used organic luminescent materials usually applied in light-emitting and nanostructure device, but still few explored in radiation dosimetry. Organic solutions of tris(8-hydroxyquinolinato) aluminum - Alq_3 and poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] - MEH-PPV were prepared to better study the impact of spectral overlap between the Alq_3 emission and MEH-PPV absorption. It is observed a blue-shift on the photoluminescence of the MEH-PPV/Alq_3 solution system from red-orange (λ_m_a_x = 598 nm) to green (λ_m_a_x = 545 nm) when the radiation dose changes from 0 to 100 Gy. This effect is attributed to the photooxidation process of MEH-PPV and was employed to design dose accumulation sensors in order to represent easily the radiation dose for cancer treatment. (author)

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)

Experimental microdosimetry in high energy radiation fields

International Nuclear Information System (INIS)

Spurny, F.; Bednar, J.; Vlcek, B.; Bottollier-Depois, J.-F.; Molokanov, A.G.

2000-01-01

To determine microdosimetric characteristics in the beams and fields of high energy panicles with the goal, also, to compare the classical method of experimental microdosimetry, a tissue equivalent low pressure proportional counter (TEPC) with the linear energy transfer (LET) spectrometer based on a chemically etched polyallyldiglycolcarbonate as a track etched detector (TED). To test the use of TED LET spectrometer in the conditions, where the use or TEPC is not possible (high energy charged particle beams at high dose rates). The results obtained with the TEPC NAUSICAA were used in this work to compare them with other data. This TEPC measures directly the linear energy in the interval between 0.15 and 1500 keV/μm in tissue, the low gas pressure (propan based TE mixture) permits to simulate a tissue element of about 3 μm. It can be used in the fields with instantaneous dose equivalent rates between 1 μSv/hour and 1 mSv/ hour. TED LET spectrometer developed to determine LET spectra between 10 and 700 keV/μm in tissue. Primarily, track-to-bulk etch rate ratios are determined through the track parameters measurements, the spectra of these ratios are convened to LET spectra using the calibration curve established by means of heavy charge panicles. The critical volume of thi spectrometer is supposed to be a few nm. There is no limit of use for the dose rate, the background tracks limit the lowest threshold to about 1 mSv, the overlapping of tracks (the highest one) to 100 mSv. Both experimental microdosimetry methods have been used in on board aircraft radiation fields, in on-Earth high energy radiation reference fields, and in the beams of protons with energies up to 300 MeV (Dubna, Moscow, Loma Linda). First, it should be emphasized, that in all high energy radiation fields studied, we concentrated our analysis on the region, where both methods overlap, i.e. between 10 and 1000 keV/μm in tissue. It should be also stressed, that the events observed in this region

High linear-energy-transfer radiation can overcome radioresistance of glioma stem-like cells to low linear-energy-transfer radiation.

Science.gov (United States)

Hirota, Yuki; Masunaga, Shin-Ichiro; Kondo, Natsuko; Kawabata, Shinji; Hirakawa, Hirokazu; Yajima, Hirohiko; Fujimori, Akira; Ono, Koji; Kuroiwa, Toshihiko; Miyatake, Shin-Ichi

2014-01-01

Ionizing radiation is applied as the standard treatment for glioblastoma multiforme (GBM). However, radiotherapy remains merely palliative, not curative, because of the existence of glioma stem cells (GSCs), which are regarded as highly radioresistant to low linear-energy-transfer (LET) photons. Here we analyzed whether or not high-LET particles can overcome the radioresistance of GSCs. Glioma stem-like cells (GSLCs) were induced from the GBM cell line A172 in stem cell culture medium. The phenotypes of GSLCs and wild-type cells were confirmed using stem cell markers. These cells were irradiated with (60)Co gamma rays or reactor neutron beams. Under neutron-beam irradiation, high-LET proton particles can be produced through elastic scattering or nitrogen capture reaction. Radiosensitivity was assessed by a colony-forming assay, and the DNA double-strand breaks (DSBs) were assessed by a histone gamma-H2AX focus detection assay. In stem cell culture medium, GSLCs could form neurosphere-like cells and express neural stem cell markers (Sox2 and Musashi) abundantly in comparison with their parental cells. GSLCs were significantly more radioresistant to gamma rays than their parental cells, but neutron beams overcame this resistance. There were significantly fewer gamma-H2AX foci in the A172 GSLCs 24 h after irradiation with gamma rays than in their parental cultured cells, while there was no apparent difference following neutron-beam irradiation. High-LET radiation can overcome the radioresistance of GSLCs by producing unrepairable DNA DSBs. High-LET radiation therapy might have the potential to overcome GBM's resistance to X-rays in a clinical setting.

High energy dosimetry

International Nuclear Information System (INIS)

Ruhm, W.

2010-01-01

Full text: Currently, quantification of doses from high-energy radiation fields is a topical issue. This is so because high-energy neutrons play an important role for radiation exposure of air crew members and personnel outside the shielding of ion therapy facilities. In an effort to study air crew exposure from cosmic radiation in detail, two Bonner Sphere Spectrometers (BSSs) have recently been installed to measure secondary neutrons from cosmic radiation, one at the environmental research station 'Schneefernerhaus' at an altitude of 2650 m on the Zugspitze mountain, Germany, the other at the Koldewey station close to the North Pole on Spitsbergen. Based on the measured neutron fluence distributions and on fluence-to-dose conversion coefficients, mean ambient dose equivalent rate values of 75.0 ± 2.9 nSv/h and 8.7 ± 0.6 nSv/h were obtained for October 2008, respectively. Neutrons with energies above about 20 MeV contribute about 50% to dose, at 2650 m. Ambient dose equivalent rates measured by means of a standard rem counter and an extended rem counter at the Schneefernerhaus confirm this result. In order to study the response of state-of-the-art radiation instrumentation in such a high-energy radiation field, a benchmark exercise that included both measurements in and simulation of the stray neutron radiation field at the high-energy particle accelerator at GSI, Germany, were performed. This CONRAD (COordinated Network for RAdiation Dosimetry) project was funded by the European Commission, and the organizational framework was provided by the European Radiation Dosimetry Group, EURADOS. The Monte Carlo simulations of the radiation field and the experimental determination of the neutron spectra with various Bonner Sphere Spectrometers suggest the neutron fluence distributions to be very similar to those of secondary neutrons from cosmic radiation. The results of this intercomparison exercise in terms of ambient dose equivalent are also discussed

Emulsion polymerization with high energy radiation

International Nuclear Information System (INIS)

Stannett, V.T.; Stahel, E.P.

1992-01-01

High energy radiation, particularly that of cobalt-60 or caesium-137 gamma-rays, provides in principle an ideal initiator for emulsion polymerization. The high free radical yields from the radiolysis of the aqueous phase combined with the high kinetic chain lengths associated with emulsion polymerization lead to a highly effective utilization of the radiation. There are other important advantages compared with the use of chemical initiators such as potassium persulfate. These are outlined in the chapter, together with some attendant disadvantages. Radiation-induced initiation is temperature independent, and low temperature polymerizations can be conducted with ease. Monomers that mainly terminate their growing chains by chain transfer to monomer give higher molecular weights at lower temperatures. Industrially, vinyl acetate is an important example of such a monomer, and it has been studied using radiation initiation. Both laboratory and pilot plant studies have been carried out and reported. The results are summarized in this chapter. Styrene is the classical example of a material that under a number of conditions closely obeys the so-called ideal Smith-Ewart kinetics. It has been found that under similar conditions but substituting radiation for potassium persulfate as the initiator, ideal kinetics were closely followed. Most of the conventional and some non-standard vinyl and diene monomers have been studied to some extent with radiation-initiated polymerizations in emulsion. To conserve space however, this chapter presents and discusses the results obtained only with styrene and vinyl acetate, both in laboratory and pilot plant investigations. Other monomers and special situations are referenced either directly or to the other available reviews. (orig.)

Photoelectric-enhanced radiation therapy with quasi-monochromatic computed tomography.

Science.gov (United States)

Jost, Gregor; Mensing, Tristan; Golfier, Sven; Lawaczeck, Rüdiger; Pietsch, Hubertus; Hütter, Joachim; Cibik, Levent; Gerlach, Martin; Krumrey, Michael; Fratzscher, Daniel; Arkadiev, Vladimir; Wedell, Reiner; Haschke, Michael; Langhoff, Norbert; Wust, Peter; Lüdemann, Lutz

2009-06-01

Photoelectric-enhanced radiation therapy is a bimodal therapy, consisting of the administration of highly radiation-absorbing substances into the tumor area and localized regional irradiation with orthovoltage x-rays. Irradiation can be performed by a modified computed tomography (CT) unit equipped with an additional x-ray optical module which converts the polychromatic, fan-shaped CT beam into a monochromatized and focused beam for energy-tuned photoelectric-enhanced radiotherapy. A dedicated x-ray optical module designed for spatial collimation, focusing, and monochromatization was mounted at the exit of the x-ray tube of a clinical CT unit. Spectrally resolved measurements of the resulting beam were performed using an energy-dispersive detection system calibrated by synchrotron radiation. The spatial photon fluence was determined by film dosimetry. Depth-dose measurements were performed and compared to the polychromatic CT and a therapeutic 6 MV beam. The spatial dose distribution in phantoms using a rotating radiation source (quasimonochromatic CT and 6 MV, respectively) was investigated by gel dosimetry. The photoelectric dose enhancement for an iodine fraction of 1% in tissue was calculated and verified experimentally. The x-ray optical module selectively filters the energy of the tungsten Kalpha emission line with an FWHM of 5 keV. The relative photon fluence distribution demonstrates the focusing characteristic of the x-ray optical module. A beam width of about 3 mm was determined at the isocenter of the CT gantry. The depth-dose measurements resulted in a half-depth value of approximately 36 mm for the CT beams (quasi-monochromatic, polychromatic) compared to 154 mm for the 6 MV beam. The rotation of the radiation source leads to a steep dose gradient at the center of rotation; the gel dosimetry yields an entrance-to-peak dose ratio of 1:10.8 for the quasi-monochromatic CT and 1:37.3 for a 6 MV beam of the same size. The photoelectric dose enhancement

Photoelectric-enhanced radiation therapy with quasi-monochromatic computed tomography

International Nuclear Information System (INIS)

Jost, Gregor; Mensing, Tristan; Golfier, Sven; Lawaczeck, Ruediger; Pietsch, Hubertus; Huetter, Joachim; Cibik, Levent; Gerlach, Martin; Krumrey, Michael; Fratzscher, Daniel; Arkadiev, Vladimir; Wedell, Reiner; Haschke, Michael; Langhoff, Norbert; Wust, Peter; Luedemann, Lutz

2009-01-01

Photoelectric-enhanced radiation therapy is a bimodal therapy, consisting of the administration of highly radiation-absorbing substances into the tumor area and localized regional irradiation with orthovoltage x-rays. Irradiation can be performed by a modified computed tomography (CT) unit equipped with an additional x-ray optical module which converts the polychromatic, fan-shaped CT beam into a monochromatized and focused beam for energy-tuned photoelectric-enhanced radiotherapy. A dedicated x-ray optical module designed for spatial collimation, focusing, and monochromatization was mounted at the exit of the x-ray tube of a clinical CT unit. Spectrally resolved measurements of the resulting beam were performed using an energy-dispersive detection system calibrated by synchrotron radiation. The spatial photon fluence was determined by film dosimetry. Depth-dose measurements were performed and compared to the polychromatic CT and a therapeutic 6 MV beam. The spatial dose distribution in phantoms using a rotating radiation source (quasi-monochromatic CT and 6 MV, respectively) was investigated by gel dosimetry. The photoelectric dose enhancement for an iodine fraction of 1% in tissue was calculated and verified experimentally. The x-ray optical module selectively filters the energy of the tungsten Kα emission line with an FWHM of 5 keV. The relative photon fluence distribution demonstrates the focusing characteristic of the x-ray optical module. A beam width of about 3 mm was determined at the isocenter of the CT gantry. The depth-dose measurements resulted in a half-depth value of approximately 36 mm for the CT beams (quasi-monochromatic, polychromatic) compared to 154 mm for the 6 MV beam. The rotation of the radiation source leads to a steep dose gradient at the center of rotation; the gel dosimetry yields an entrance-to-peak dose ratio of 1:10.8 for the quasi-monochromatic CT and 1:37.3 for a 6 MV beam of the same size. The photoelectric dose enhancement factor

Photoelectric-enhanced radiation therapy with quasi-monochromatic computed tomography

Energy Technology Data Exchange (ETDEWEB)

Jost, Gregor; Mensing, Tristan; Golfier, Sven; Lawaczeck, Ruediger; Pietsch, Hubertus; Huetter, Joachim; Cibik, Levent; Gerlach, Martin; Krumrey, Michael; Fratzscher, Daniel; Arkadiev, Vladimir; Wedell, Reiner; Haschke, Michael; Langhoff, Norbert; Wust, Peter; Luedemann, Lutz [TRG Diagnostic Imaging, Bayer Schering Pharma AG, 13353 Berlin (Germany); Department of Radiotherapy, Charite Medical Centre, 13353 Berlin (Germany); TRG Diagnostic Imaging, Bayer Schering Pharma AG, 13353 Berlin (Germany); Physikalisch-Technische Bundesanstalt, 10587 Berlin (Germany); Institute of Applied Photonics e.V., 12489 Berlin (Germany); Institute for Scientific Instruments GmbH, 12489 Berlin (Germany); Department of Radiotherapy, Charite Medical Centre, 13353 Berlin (Germany)

2009-06-15

Photoelectric-enhanced radiation therapy is a bimodal therapy, consisting of the administration of highly radiation-absorbing substances into the tumor area and localized regional irradiation with orthovoltage x-rays. Irradiation can be performed by a modified computed tomography (CT) unit equipped with an additional x-ray optical module which converts the polychromatic, fan-shaped CT beam into a monochromatized and focused beam for energy-tuned photoelectric-enhanced radiotherapy. A dedicated x-ray optical module designed for spatial collimation, focusing, and monochromatization was mounted at the exit of the x-ray tube of a clinical CT unit. Spectrally resolved measurements of the resulting beam were performed using an energy-dispersive detection system calibrated by synchrotron radiation. The spatial photon fluence was determined by film dosimetry. Depth-dose measurements were performed and compared to the polychromatic CT and a therapeutic 6 MV beam. The spatial dose distribution in phantoms using a rotating radiation source (quasi-monochromatic CT and 6 MV, respectively) was investigated by gel dosimetry. The photoelectric dose enhancement for an iodine fraction of 1% in tissue was calculated and verified experimentally. The x-ray optical module selectively filters the energy of the tungsten K{alpha} emission line with an FWHM of 5 keV. The relative photon fluence distribution demonstrates the focusing characteristic of the x-ray optical module. A beam width of about 3 mm was determined at the isocenter of the CT gantry. The depth-dose measurements resulted in a half-depth value of approximately 36 mm for the CT beams (quasi-monochromatic, polychromatic) compared to 154 mm for the 6 MV beam. The rotation of the radiation source leads to a steep dose gradient at the center of rotation; the gel dosimetry yields an entrance-to-peak dose ratio of 1:10.8 for the quasi-monochromatic CT and 1:37.3 for a 6 MV beam of the same size. The photoelectric dose enhancement

Internal high linear energy transfer (LET) targeted radiotherapy for cancer

International Nuclear Information System (INIS)

Allen, Barry J

2006-01-01

High linear energy transfer (LET) radiation for internal targeted therapy has been a long time coming on to the medical therapy scene. While fundamental principles were established many decades ago, the clinical implementation has been slow. Localized neutron capture therapy, and more recently systemic targeted alpha therapy, are at the clinical trial stage. What are the attributes of these therapies that have led a band of scientists and clinicians to dedicate so much of their careers? High LET means high energy density, causing double strand breaks in DNA, and short-range radiation, sparing adjacent normal tissues. This targeted approach complements conventional radiotherapy and chemotherapy. Such therapies fail on several fronts. Foremost is the complete lack of progress for the control of primary GBM, the holy grail for cancer therapies. Next is the inability to regress metastatic cancer on a systemic basis. This has been the task of chemotherapy, but palliation is the major application. Finally, there is the inability to inhibit the development of lethal metastatic cancer after successful treatment of the primary cancer. This review charts, from an Australian perspective, the developing role of local and systemic high LET, internal radiation therapy. (review)

Whole-Pelvic Nodal Radiation Therapy in the Context of Hypofractionation for High-Risk Prostate Cancer Patients: A Step Forward

International Nuclear Information System (INIS)

Kaidar-Person, Orit; Roach, Mack; Créhange, Gilles

2013-01-01

Given the low α/β ratio of prostate cancer, prostate hypofractionation has been tested through numerous clinical studies. There is a growing body of literature suggesting that with high conformal radiation therapy and even with more sophisticated radiation techniques, such as high-dose-rate brachytherapy or image-guided intensity modulated radiation therapy, morbidity associated with shortening overall treatment time with higher doses per fraction remains low when compared with protracted conventional radiation therapy to the prostate only. In high-risk prostate cancer patients, there is accumulating evidence that either dose escalation to the prostate or hypofractionation may improve outcome. Nevertheless, selected patients who have a high risk of lymph node involvement may benefit from whole-pelvic radiation therapy (WPRT). Although combining WPRT with hypofractionated prostate radiation therapy is feasible, it remains investigational. By combining modern advances in radiation oncology (high-dose-rate prostate brachytherapy, intensity modulated radiation therapy with an improved image guidance for soft-tissue sparing), it is hypothesized that WPRT could take advantage of recent results from hypofractionation trials. Moreover, the results from hypofractionation trials raise questions as to whether hypofractionation to pelvic lymph nodes with a high risk of occult involvement might improve the outcomes in WPRT. Although investigational, this review discusses the challenging idea of WPRT in the context of hypofractionation for patients with high-risk prostate cancer

Whole-Pelvic Nodal Radiation Therapy in the Context of Hypofractionation for High-Risk Prostate Cancer Patients: A Step Forward

Energy Technology Data Exchange (ETDEWEB)

Kaidar-Person, Orit [Division of Oncology, Rambam Health Care Campus, Haifa (Israel); Roach, Mack [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Créhange, Gilles, E-mail: gcrehange@cgfl.fr [Department of Radiation Oncology, Georges-François Leclerc Cancer Center, Dijon (France)

2013-07-15

Given the low α/β ratio of prostate cancer, prostate hypofractionation has been tested through numerous clinical studies. There is a growing body of literature suggesting that with high conformal radiation therapy and even with more sophisticated radiation techniques, such as high-dose-rate brachytherapy or image-guided intensity modulated radiation therapy, morbidity associated with shortening overall treatment time with higher doses per fraction remains low when compared with protracted conventional radiation therapy to the prostate only. In high-risk prostate cancer patients, there is accumulating evidence that either dose escalation to the prostate or hypofractionation may improve outcome. Nevertheless, selected patients who have a high risk of lymph node involvement may benefit from whole-pelvic radiation therapy (WPRT). Although combining WPRT with hypofractionated prostate radiation therapy is feasible, it remains investigational. By combining modern advances in radiation oncology (high-dose-rate prostate brachytherapy, intensity modulated radiation therapy with an improved image guidance for soft-tissue sparing), it is hypothesized that WPRT could take advantage of recent results from hypofractionation trials. Moreover, the results from hypofractionation trials raise questions as to whether hypofractionation to pelvic lymph nodes with a high risk of occult involvement might improve the outcomes in WPRT. Although investigational, this review discusses the challenging idea of WPRT in the context of hypofractionation for patients with high-risk prostate cancer.

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.

Physics of intense, high energy radiation effects.

Energy Technology Data Exchange (ETDEWEB)

Hjalmarson, Harold Paul; Hartman, E. Frederick; Magyar, Rudolph J.; Crozier, Paul Stewart

2011-02-01

This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic

Postoperative radiation therapy after hip replacement in high-risk patients for development of heterotopic bone formation

International Nuclear Information System (INIS)

Hashem, R.; Rene, N.; Souhami, L.; Tanzer, M.; Evans, M.

2011-01-01

Purpose. - To report the results of postoperative radiation therapy in preventing the development of heterotopic bone formation after hip replacement surgery in high-risk patients. Patients and methods. - Between 1991 and 2007, 44 patients were preventively treated with postoperative RT after total hip replacement. In total, 47 hips were treated. All patients were considered at high risk for developing heterotopic bone formation. Most patients (63.5%) were treated because of a history of severe osteoarthritis or ankylosing spondylitis. All patients were treated with shaped parallel-opposed fields with a single fraction of 7 Gy using 6 or 18 MV photons. Most patients (94%) received radiation therapy within 72 hours postoperative and in only three patients radiation therapy was delivered after 72 hours post-surgery (5-8 days). Results. - Minimum follow-up was 1 year. There were 18 females and 26 males. Median age was 63 years (range: 18-80). Treatments were well tolerated and no acute toxicity was seen post-radiation therapy. Only one of the 47 hips (2%) developed heterotopic bone formation. This patient received postoperative radiation therapy to both hips but only developed heterotopic bone formation in one of them. None of the three patients treated beyond 72 hours failed. To date no late toxicity has been observed. Conclusion. - The use of postoperative radiation therapy was an effective and safe treatment in the prevention of heterotopic bone formation in a high-risk group of patients undergoing total hip replacement. (authors)

Radiative energy losses from a high-current air-blast arc

International Nuclear Information System (INIS)

Strachan, D.C.; Lidgate, D.; Jones, G.R.

1977-01-01

The importance of total radiation losses from high-current arcs burning in highly accelerated air flows representative of conditions existing in commercial gas-blast switchgear has been investigated. Such losses have been measured both in the high-pressure region upstream of a shaped orifice, where gas velocities are low, and in the region downstream where velocities become supersonic and pressure conditions approach ambient. The dominance of upstream electrode vapor as the source of plasma radiation losses is demonstrated and the importance of radiated losses within the arc energy balance is examined using measured values of axial electric field. For upstream electrodes of elkonite (sintered copper/tungsten) as used in high-power gas-blast circuit breakers, it is shown that some 30--40% of the electrical energy input upstream of the orifice is lost as radiation, while downstream this figure becomes 10--20%. The effect of reservoir pressure on arc electric fields is examined and the contribution to this effect of radiation losses is quantified

Results of high energy x-ray therapy of gastric carcinoma, 2. Recurrent gastric carcinoma

Energy Technology Data Exchange (ETDEWEB)

Asakawa, H; Otawa, H; Yamada, S [Miyagi Prefectural Adult Disease Center, Natori (Japan)

1979-01-01

Thirty cases with recurrent gastric carcinoma were treated with a combination of high energy x-ray and some anti-cancer drugs at Miyagi Seijinbyo Center between 1967 and 1977. Twenty three cases of them tolerated well such treatment; the irradiated dose was more than 4000 rad without any serious complication. The response of recurrent tumor to irradiation was marked in 11 lesions of 21 local recurrences and 4 metastases of the lymph node. The survival rates of those irradiated more than 4000 rad were 22% at one year, 15% at two years and 5% at three years. The median survival month was 6,9 months. These rates obtained in a combined radiation therapy seemed to be well matched for those reported by other authors in a surgical management of recurrent gastric carcinoma. As a conclusion, it was suggested that a combined radiation therapy with some anticancer drugs should be an effective procedure to prolong the life of a patient of recurrent gastric carcinoma.

Radiation Build-Up Of High Energy Gamma In Shielding Of High Atomic Number

International Nuclear Information System (INIS)

Yuliati, Helfi; Akhadi, Mukhlis

2000-01-01

Research to observe effect of radiation build-up factor (b) in iron (Fe) and lead (Pb) for high energy gamma shielding from exp.137 Cs (E gamma : 662 keV) and exp.60 Co (E gamma : 1332 keV) sources has been carried out. Research was conducted bt counting of radiation intensity behind shielding with its thickness vary from 1 to 5 times of half value thickness (HVT). NaI (TI) detector which connected to multi channel analyzer (MCA) was used for the counting. Calculation result show that all of b value are near to 1 (b∼1) both for Fe and Pb. Without inserting b in calculation, from the experiment it was obtained HVT value of Fe for high gamma radiation of 662 and 1332 keV were : (12,94 n 0,03) mm and (17,33 n 0,01) mm with their deviation standards were 0,2% and 0,06% respectively. Value of HVT for Pb with the same energy were : (6,31 n 0,03) mm and (11,86 n 0,03) mm with their deviation standars were : 0,48% and 0,25% respectively. HVL concept could be applied directly to estimate shielding thickness of high atomic number of high energy gamma radiation, without inserting correction of radiation build-up factor

High linear-energy-transfer radiation can overcome radioresistance of glioma stem-like cells to low linear-energy-transfer radiation

International Nuclear Information System (INIS)

Hirota, Yuki; Kawabata, Shinji; Kuroiwa, Toshihiko; Miyatake, Shin-ichi; Masunaga, Shin-ichiro; Kondo, Natsuko; Ono, Koji; Hirakawa, Hirokazu; Yajima, Hirohiko; Fujimori, Akira

2014-01-01

Ionizing radiation is applied as the standard treatment for glioblastoma multiforme (GBM). However, radiotherapy remains merely palliative, not curative, because of the existence of glioma stem cells (GSCs), which are regarded as highly radioresistant to low linear-energy-transfer (LET) photons. Here we analyzed whether or not high-LET particles can overcome the radioresistance of GSCs. Glioma stem-like cells (GSLCs) were induced from the GBM cell line A172 in stem cell culture medium. The phenotypes of GSLCs and wild-type cells were confirmed using stem cell markers. These cells were irradiated with 60 Co gamma rays or reactor neutron beams. Under neutron-beam irradiation, high-LET proton particles can be produced through elastic scattering or nitrogen capture reaction. Radiosensitivity was assessed by a colony-forming assay, and the DNA double-strand breaks (DSBs) were assessed by a histone gamma-H2AX focus detection assay. In stem cell culture medium, GSLCs could form neurosphere-like cells and express neural stem cell markers (Sox2 and Musashi) abundantly in comparison with their parental cells. GSLCs were significantly more radioresistant to gamma rays than their parental cells, but neutron beams overcame this resistance. There were significantly fewer gamma-H2AX foci in the A172 GSLCs 24 h after irradiation with gamma rays than in their parental cultured cells, while there was no apparent difference following neutron-beam irradiation. High-LET radiation can overcome the radioresistance of GSLCs by producing unrepairable DNA DSBs. High-LET radiation therapy might have the potential to overcome GBM's resistance to X-rays in a clinical setting. (author)

High energy radiation from black holes gamma rays, cosmic rays, and neutrinos

CERN Document Server

Dermer, Charles D

2009-01-01

Bright gamma-ray flares observed from sources far beyond our Milky Way Galaxy are best explained if enormous amounts of energy are liberated by black holes. The highest- energy particles in nature--the ultra-high-energy cosmic rays--cannot be confined by the Milky Way's magnetic field, and must originate from sources outside our Galaxy. Understanding these energetic radiations requires an extensive theoretical framework involving the radiation physics and strong-field gravity of black holes. In High Energy Radiation from Black Holes, Charles Dermer and Govind Menon present a systemat

Modern Radiation Therapy for Hodgkin Lymphoma

DEFF Research Database (Denmark)

Specht, Lena; Yahalom, Joachim; Illidge, Tim

2014-01-01

Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced...... 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......, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom...

A Variable Energy CW Compact Accelerator for Ion Cancer Therapy

Energy Technology Data Exchange (ETDEWEB)

Johnstone, Carol J. [Fermilab; Taylor, J. [Huddersfield U.; Edgecock, R. [Huddersfield U.; Schulte, R. [Loma Linda U.

2016-03-10

Cancer is the second-largest cause of death in the U.S. and approximately two-thirds of all cancer patients will receive radiation therapy with the majority of the radiation treatments performed using x-rays produced by electron linacs. Charged particle beam radiation therapy, both protons and light ions, however, offers advantageous physical-dose distributions over conventional photon radiotherapy, and, for particles heavier than protons, a significant biological advantage. Despite recognition of potential advantages, there is almost no research activity in this field in the U.S. due to the lack of clinical accelerator facilities offering light ion therapy in the States. In January, 2013, a joint DOE/NCI workshop was convened to address the challenges of light ion therapy [1], inviting more than 60 experts from diverse fields related to radiation therapy. This paper reports on the conclusions of the workshop, then translates the clinical requirements into accelerat or and beam-delivery technical specifications. A comparison of available or feasible accelerator technologies is compared, including a new concept for a compact, CW, and variable energy light ion accelerator currently under development. This new light ion accelerator is based on advances in nonscaling Fixed-Field Alternating gradient (FFAG) accelerator design. The new design concepts combine isochronous orbits with long (up to 4m) straight sections in a compact racetrack format allowing inner circulating orbits to be energy selected for low-loss, CW extraction, effectively eliminating the high-loss energy degrader in conventional CW cyclotron designs.

Radiation therapy for gastric cancer

International Nuclear Information System (INIS)

Dobelbower, R.R.; Bagne, F.; Ajlouni, M.I.; Milligan, A.J.

1988-01-01

Adenocarcinoma of the stomach is a moderately radioresponsive neoplasm. Attempts to treat patients with unresectable disease with external beam radiation therapy alone have generally failed because of problems with tumor localization and adequate dose delivery as well as the inherent radioresponsiveness of the gastric mucosa and the organs intimately related to the stomach. Combining external beam therapy and chemotherapy (acting as a systemic agent and as a radiosensitizer) seems to be of some (albeit limited) benefit in the management of unresectable adenocarcinoma of the stomach. Optimum combinations of radiation therapy, chemotherapy, and radiation sensitizers in this situation remain to be determined. The authors discuss strides which have been made in the treatment of gastric cancer. They also address the unanswered clinical questions which remain regarding the use of radiation therapy in the treatment of this highly lethal disease

Energy dependence of ulrathin LiF-dosemeters for high energy electrons and high energy X-radiation

International Nuclear Information System (INIS)

Kupfer, T.

1977-02-01

The energy dependence of ultrathin LiF-dosemeters for high energy electrons (5-40 MeV) and high energy X-radiation (6 MV, 42 MV) is experimentally determined. The experimental values are compared to values calculted earlier by other authors. The influence of the thickness of the dosemeters have been considered by comparison of experimental values for 0.03 mm thick dosemeters and theoretical values for 0.13 mm and 0.38 mm thick ones. Also different commersially available dosemeters have been compared by experiments. It is difficult to draw any other conclutions about the energy dependence than that the variation of the relative responce is within +- 3 percent (2S). However the results seems to be sulficient for clinical applications

Local dose enhancement in radiation therapy: Monte Carlo simulation study

International Nuclear Information System (INIS)

Silva, Laura E. da; Nicolucci, Patricia

2014-01-01

The development of nanotechnology has boosted the use of nanoparticles in radiation therapy in order to achieve greater therapeutic ratio between tumor and healthy tissues. Gold has been shown to be most suitable to this task due to the high biocompatibility and high atomic number, which contributes to a better in vivo distribution and for the local energy deposition. As a result, this study proposes to study, nanoparticle in the tumor cell. At a range of 11 nm from the nanoparticle surface, results have shown an absorbed dose 141 times higher for the medium with the gold nanoparticle compared to the water for an incident energy spectrum with maximum photon energy of 50 keV. It was also noted that when only scattered radiation is interacting with the gold nanoparticles, the dose was 134 times higher compared to enhanced local dose that remained significant even for scattered radiation. (author)

Radiation Fields in High Energy Accelerators and their impact on Single Event Effects

CERN Document Server

García Alía, Rubén; Wrobel, Frédéric; Brugger, Markus

Including calculation models and measurements for a variety of electronic components and their concerned radiation environments, this thesis describes the complex radiation field present in the surrounding of a high-energy hadron accelerator and assesses the risks related to it in terms of Single Event Effects (SEE). It is shown that this poses not only a serious threat to the respective operation of modern accelerators but also highlights the impact on other high-energy radiation environments such as those for ground and avionics applications. Different LHC-like radiation environments are described in terms of their hadron composition and energy spectra. They are compared with other environments relevant for electronic component operation such as the ground-level, avionics or proton belt. The main characteristic of the high-energy accelerator radiation field is its mixed nature, both in terms of hadron types and energy interval. The threat to electronics ranges from neutrons of thermal energies to GeV hadron...

Radiation therapy services in South Africa

African Journals Online (AJOL)

available were pooled according to health regions and related to population ... Megavoltage radiation therapy units in South Africa. Photon. Electron. Machine energy beam. Tvl .... Remote afrerloading brachytherapy devices have developed ...

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).

Occurrence of chronic esophageal ulcer after high dose rate intraluminal radiation therapy for esophageal cancer

International Nuclear Information System (INIS)

Soejima, Toshinori; Hirota, Saeko; Okamoto, Yoshiaki; Obayashi, Kayoko; Takada, Yoshiki

1995-01-01

Ninety-eight patients with esophageal cancer were treated by high dose rate intraluminal radiation therapy at the Department of Radiology of the Hyogo Medical Center for Adults between January 1982 and December 1993. Twenty patients with complete response after intraluminal radiation therapy, who were followed up with esophageal fiberscopy in our institute, were reviewed. The one-year cumulative rate of occurrence of esophageal ulcers was 81%, and in 69% of the cases the ulcers occurred from 4 to 8 months after completion of intraluminal radiation therapy. We graded esophageal ulcer by fiberscopic findings. Grade 0 was defined as no ulcer, grade 1 as superficial ulcer, grade 2 as deep ulcer, grade 3 as circumferencial ulcer, and severe stenosis. Factors related to grade were studied, and shorter distances from the source to the surface of the mucosa and lower surface doses of intraluminal radiation therapy appear to reduce the severity as graded on the above scale, of the esophageal ulcer. Four of the five 2-year recurrence-free patients suffered esophageal ulcers, which were cured from 15 to 22 months after intraluminal radiation therapy. However ulcers recurred in two patients, ong term care was thought to be necessary. (author)

LET spectrometry with track etch detectors-Use in high-energy radiation fields

International Nuclear Information System (INIS)

Jadrnickova, I.; Spurny, F.

2008-01-01

For assessing the risk from ionizing radiation it is necessary to know not only the absorbed dose but also the quality of the radiation; radiation quality is connected with the physical quantity linear energy transfer (LET). One of the methods of determination of LET is based on chemically etched track detectors. This contribution concerns with a spectrometer of LET based on the track detectors and discusses some results obtained at: ·high-energy radiation reference field created at the SPS accelerator at CERN; and ·onboard of International Space Station where track-etch based LET spectrometer has been exposed 273 days during 'Matrjoshka - R' experiment. Results obtained are compared with the results of studies at some lower-energy neutron sources; some conclusions on the registrability of neutrons and the ability of this spectrometer to determine dose equivalent in high-energy radiation fields are formulated

Radiation-hard silicon photonics for high energy physics and beyond

CERN Multimedia

CERN. Geneva

2016-01-01

Silicon photonics (SiPh) is currently being investigated as a promising technology for future radiation hard optical links. The possibility of integrating SiPh devices with electronics and/or silicon particle sensors as well as an expected very high resistance against radiation damage make this technology particularly interesting for potential use close to the interaction points in future in high energy physics experiments and other radiation-sensitive applications. The presentation will summarize the outcomes of the research on radiation hard SiPh conducted within the ICE-DIP projected.

Comparison of particle-radiation-therapy modalities

International Nuclear Information System (INIS)

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

1981-01-01

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

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)

Gold Nanoparticles and Their Alternatives for Radiation Therapy Enhancement

Directory of Open Access Journals (Sweden)

Daniel R. Cooper

2014-10-01

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

Development of nuclear energy and radiation textbooks for high school students

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Koo; Park, Pil Han; Choi, Yoon Seok; Kim, Wook; Jeong, Im Soon; Han, Eun Ok [Dept. of Education and Research, Korea Academy of Nuclear Safety, Seoul (Korea, Republic of)

2015-04-15

This study aimed to develop textbooks about nuclear energy and radiation targeting high school students-the leaders of the next generation. Students learn about nuclear power generation and radiation through minimal information in science textbooks; most students acquire concepts through teaching-learning activities between teachers and students. Therefore, if a science teacher has an inaccurate perception about nuclear energy and radiation, this may have an improper influence on students. Before the failure of securing social acceptance due to ignorance about nuclear energy and radiation leads to biased political effects, the correct information should be provided in schools to allow future generations to develop educated value judgments. The present textbooks were developed as a part of such effort.

Development of nuclear energy and radiation textbooks for high school students

International Nuclear Information System (INIS)

Lee, Seung Koo; Park, Pil Han; Choi, Yoon Seok; Kim, Wook; Jeong, Im Soon; Han, Eun Ok

2015-01-01

This study aimed to develop textbooks about nuclear energy and radiation targeting high school students-the leaders of the next generation. Students learn about nuclear power generation and radiation through minimal information in science textbooks; most students acquire concepts through teaching-learning activities between teachers and students. Therefore, if a science teacher has an inaccurate perception about nuclear energy and radiation, this may have an improper influence on students. Before the failure of securing social acceptance due to ignorance about nuclear energy and radiation leads to biased political effects, the correct information should be provided in schools to allow future generations to develop educated value judgments. The present textbooks were developed as a part of such effort

Measurement of energy transitions for the decay radiations of 75Ge and 69Ge in a high purity germanium detector

Science.gov (United States)

Aydın, Güral; Usta, Metin; Oktay, Adem

2018-06-01

Photoactivation experiments have a wide range of application areas in nuclear, particle physics, and medical physics such as measuring energy levels and half-lifes of nuclei, experiments for understanding imaging methods in medicine, isotope production for patient treatment, radiation security and transportation, radiation therapy, and astrophysics processes. In this study, some energy transition values of the decay radiations of 75Ge and 69Ge, which are the products of photonuclear reactions (γ, n) with germanium isotopes (75Ge and 69Ge), were measured. The gamma spectrum as a result of atomic transitions were analysed by using a high purity semiconductor germanium detector and the energy transition values which are presented here were compared with the ones which are the best in literature. It was observed that the results presented are in agreement with literature in error range and some results have better precisions.

A new era in nuclear energy science. When will radiation application receive citizenship ranking along with energy utilization

International Nuclear Information System (INIS)

Tabata, Yoneho; Tagawa, Seiichi; Saito, Naoki; Fujii, Yasuhiko

2005-01-01

Japan has been obtaining definite results in these decades in both fields of nuclear power generation (energy utilization) and radiation application thus contributing to a sustainable development of the world. The present special issue of 'Atom Eye' introduces (1) Japanese achievements in cooperative relationships with developing countries in the field of radiation applications, (2) history of research and development of radiation-utilization techniques in Japan, (3) present status of quantum-beam applications in life-science, medial application, and nano-technology, etc, (4) applications of high-intensity neutron source, (5) cancer therapy using high-energy heavy-ion beams, (6) radiation sterilizations, (7) radiation mutations, (8) three interviewer's reports visiting several research institutes of radiation applications in Japan, and introduction of (9) a bencher enterprise and also (10) an accelerator business. (S. Ohno)

Shielding Design and Leaking Measurement for the High Energy Radiation Room

International Nuclear Information System (INIS)

Chu, Sung Sil

1979-01-01

An optimum shielding design and the computation of protective barriers for high energy radiation therapy room, Toshiba 13 MeV , are presented. We obtained following results by comparison between the p recalculating values and actual survey after complete installation of radio generating units. 1. The precalculating values of protective barrier are 5 times more protective than that of actual measurement. 2. The dose rate during exposure are 2-10 mR /hr at out of the door and the control room. 3. The exposure doses for occupationally persons are relatively low levels, the average values of exposure dose is 10-50 mR per month. 4. The foul smelling and ozone gas production from long exposure of cancer patients cannot be eliminated when the room is ill ventilated

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)

Radiation of transient high-current arcs: energy measurements in the optical range

International Nuclear Information System (INIS)

Bauchire, J M; Hong, D; Rabat, H; Riquel, G

2012-01-01

When no protection is used, the radiation emitted by a high-power electric arc can be dangerous for the eyes and the skin of a person. To ensure effective protection, it is first necessary to know the energy emitted by such arcs. The aim of our work was to experimentally determine the energy emitted by high-current (from 4 to 40 kA) transient arcs, for two different (10 cm and 2 m) lengths and for electrodes in copper or steel. These experiments enabled the radiative energy of the arcs to be quantified and also showed the influence of metal vapors in the spectral distribution of the radiation.

System for determining absorbed dose and its distribution for high-energy electron radiation

International Nuclear Information System (INIS)

Hegewald, H.; Wulff, W.

1977-01-01

Taking into account the polarization effect, the dose determination for high-energy electron radiation from particle accelerators depends on the knowledge of the energy dependence of the mass stopping power. Results obtained with thermoluminescent dosemeters agree with theoretical values. For absorbed dose measurements the primary energy of electron radiation has been determined by nuclear photoreactions, and the calculation of the absorbed dose from charge measurements by means of the mass stopping power is described. Thus the calibration of ionization chambers for high-energy electron radiation by absolute measurements with the Faraday cage and chemical dosemeters has become possible. (author)

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

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

International Nuclear Information System (INIS)

Hess, Clayton B.; Thompson, Holly M.; Benedict, Stanley H.; Seibert, J. Anthony; Wong, Kenneth; Vaughan, Andrew T.; Chen, Allen M.

2016-01-01

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.”

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.”.

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.

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.

High-energy extracorporeal shock wave therapy as a treatment for chronic noninsertional Achilles tendinopathy.

Science.gov (United States)

Furia, John P

2008-03-01

High-energy extracorporeal shock wave therapy has been shown to be an effective treatment for chronic insertional Achilles tendinopathy. The results of high-energy shock wave therapy for chronic noninsertional Achilles tendinopathy have not been determined. Shock wave therapy is an effective treatment for noninsertional Achilles tendinopathy. Case control study; Level of evidence, 3. Thirty-four patients with chronic noninsertional Achilles tendinopathy were treated with a single dose of high-energy shock wave therapy (shock wave therapy group; 3000 shocks; 0.21 mJ/mm(2); total energy flux density, 604 mJ/mm(2)). Thirty-four patients with chronic noninsertional Achilles tendinopathy were treated not with shock wave therapy but with additional forms of nonoperative therapy (control group). All shock wave therapy procedures were performed using regional anesthesia. Evaluation was by change in visual analog score and by Roles and Maudsley score. One month, 3 months, and 12 months after treatment, the mean visual analog scores for the control and shock wave therapy groups were 8.4 and 4.4 (P wave therapy and control groups were 12 and 0 (P wave therapy group than in the control group (P wave therapy is an effective treatment for chronic noninsertional Achilles tendinopathy.

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)

High-energy irradiation in the management of chondrosarcoma

International Nuclear Information System (INIS)

Kim, R.Y.; Salter, M.M.; Brascho, D.J.

1983-01-01

We present a retrospective analysis of seven patients with chondrosarcoma of the bone treated by high-energy irradiation between 1961 and 1976. Its major role in this series was prevention of local recurrence in cases with inadequate resection. In three of the five cases in which radiation therapy was adjuvant rather than primary treatment, long-term local control was obtained in a dose of 5,000 to 6,500 rads in five to six weeks. Although primary treatment of chondrosarcoma is surgical, high-dose radiation therapy is indicated when surgical resection is not possible. Chondrosarcoma can respond to high doses of irradiation even though the response is slow

RADIATION THERAPY COMMUNICATION-REIRRADIATION OF A NASAL TUMOR IN A BRACHYCEPHALIC DOG USING INTENSITY MODULATED RADIATION THERAPY.

Science.gov (United States)

Rancilio, Nicholas J; Custead, Michelle R; Poulson, Jean M

2016-09-01

A 5-year-old spayed female Shih Tzu was referred for evaluation of a nasal transitional carcinoma. A total lifetime dose of 117 Gy was delivered to the intranasal mass in three courses over nearly 2 years using fractionated intensity modulated radiation therapy (IMRT) to spare normal tissues. Clinically significant late normal tissue side effects were limited to bilaterally diminished tear production. The patient died of metastatic disease progression 694 days after completion of radiation therapy course 1. This case demonstrates that retreatment with radiation therapy to high lifetime doses for recurrent local disease may be well tolerated with IMRT. © 2016 American College of Veterinary Radiology.

The response of film badge dosemeters to high energy photon radiation

International Nuclear Information System (INIS)

Playle, T.S.

1988-12-01

The sites of the earlier magnox reactor power stations at Berkeley and Bradwell in the United Kingdom are subject to 6 MeV photon radiation from the coolant gas. Since 1966 the Central Electricity Generating Board has included in its film badge personal dosimetry procedures an algorithm for applying a correction for over-response to high energy photon radiation. The correction is based on laboratory irradiations using a source of pure 6 MeV photon radiation. Recently, the opportunity arose to evaluate the response of the film badges at locations around the Berkeley reactors where spectrum-dependent dose equivalent rates had been measured. This report compares the response of the film badge in these characterised radiation environments with the response measured in the calibration laboratory. It is concluded that in the location where measurements were made, the high energy enhancement of measured dose was obscured by the effects of low energy scattered radiation, and it is considered that this will be the case for all practical situations on the power station site. There is therefore no advantage in using the 6 MeV correction factors for routine film badge dosimetry in these locations. (author)

Shielding for high energy, high intensity electron accelerator installation

International Nuclear Information System (INIS)

Warawas, C.; Chongkum, S.

1997-03-01

The utilization of electron accelerators (eBA) is gradually increased in Thailand. For instance, a 30-40 MeV eBA are used for tumor and cancer therapy in the hospitals, and a high current eBA in for gemstone colonization. In the near future, an application of eBA in industries will be grown up in a few directions, e.g., flue gases treatment from the coal fire-power plants, plastic processing, rubber vulcanization and food preservation. It is the major roles of Office of Atomic Energy for Peace (OAEP) to promote the peaceful uses of nuclear energy and to regulate the public safety and protection of the environment. By taking into account of radiation safety aspect, high energy electrons are not only harmful to human bodies, but the radioactive nuclides can be occurred. This report presents a literature review by following the National Committee on Radiation Protection and Measurements (NCRP) report No.31. This reviews for parametric calculation and shielding design of the high energy (up to 100 MeV), high intensity electron accelerator installation

Modern radiation therapy for primary cutaneous lymphomas

DEFF Research Database (Denmark)

Specht, Lena; Dabaja, Bouthaina; Illidge, Tim

2015-01-01

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......, 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....

Place of radiation therapy for the treatment of gynecologic and urologic tumors in 1994

International Nuclear Information System (INIS)

Maulard-Durdux, C.; Housset, M.

1995-01-01

External-beam radiation therapy and brachytherapy are currently used both as curative and as palliative therapy in patients with gynecologic and urologic tumors. Ionizing radiation plays a key role in the locoregional control of uterine and prostatic tumors, in particular in combination with surgery. External-beam radiation therapy in combination with concomitant radiosensitizing chemotherapy may allow conservation of the bladder in patients with infiltrating vesical tumors classically treated by cystectomy. It has beneficial effects on some of the most incapacitating complications of these cancers: its hemostatic effect is valuable in patients with vaginal bleeding or hematuria and it relieves the pain due to bone metastases, which are particularly common in prostatic cancer. Furthermore, use of high energy accelerators, development of better imaging techniques, and advances in dosimetry have substantially reduced the rate of delayed radiation-induced complications. Thus, external-beam radiation therapy and brachytherapy are important tools for the treatment of gynecologic and urologic tumors. A discussion is provided of the role of radiation therapy in the four most common types of gynecologic and urologic cancer: cancers of the prostate, bladder, uterine cervix, and uterine corpus. (authors). 52 refs., 2 tabs

Simultaneous adjuvant radiation therapy and chemotherapy in high-risk breast cancer--toxicity and dose modification: a trans-tasman radiation oncology group multi-institution study

International Nuclear Information System (INIS)

Denham, James W.; Hamilton, Christopher S.; Christie, David; O'Brien, Maree; Bonaventura, Antonino; Stewart, John F.; Ackland, Stephen P.; Lamb, David S.; Spry, Nigel A.; Dady, Peter; Atkinson, Christopher H.; Wynne, Christopher; Joseph, David J.

1995-01-01

Purpose: To establish the toxicity profile of simultaneously administered postoperative radiation therapy and CMF chemotherapy as a prelude to a randomized controlled study addressing the sequencing of the two modalities. Methods and Materials: One hundred and thirty eight breast cancer patients at high risk of locoregional, as well as systemic relapse, who were referred to three centers in Australia and New Zealand were treated with postoperative radiation therapy and chemotherapy simultaneously. Acute toxicity and dose modifications in these patients were compared with 83 patients treated over the same time frame with chemotherapy alone. In a separate study the long-term radiation and surgical effects in 24 patients treated simultaneously with radiation therapy and chemotherapy at Newcastle (Australia) following conservative surgery were compared with 23 matched patients treated at Newcastle with radiation therapy alone. Results: Myelotoxicity was increased in patients treated simultaneously with radiation therapy and chemotherapy. The effect was not great, but may have contributed to chemotherapy dose reductions. Lymphopenia was observed to be the largest factor in total white cell depressions caused by the simultaneous administration of radiation therapy. Postsurgical appearances were found to so dominate long-term treatment effects on the treated breast that the effect of radiation therapy dose and additional chemotherapy was difficult to detect. Conclusion: Studies addressing the sequencing of radiation therapy and chemotherapy will necessarily be large because adverse effects from administering the two modalities simultaneously are not great. The present study has endorsed the importance in future studies of stratification according to the extent and type of surgery and adherence to a single strict policy of chemotherapy dose modification

Radiation exposure for 'caregivers' during high-dose outpatient radioiodine therapy

International Nuclear Information System (INIS)

Marriott, C. J.; Webber, C. E.; Gulenchyn, K. Y.

2007-01-01

On 27 occasions, radiation doses were measured for a family member designated as the 'caregiver' for a patient receiving high-dose radioiodine outpatient therapy for differentiated thyroid carcinoma. For 25 of the administrations, patients received 3.7 GBq of 131 I. Radiation doses for the designated caregivers were monitored on an hourly basis for 1 week using electronic personal dosemeters. The average penetrating dose was 98±64 μSv. The maximum penetrating dose was 283 μSv. Measured dose rate profiles showed that, on average, one-third of the caregiver dose was received during the journey home from hospital. The mean dose rate profile showed rapid clearance of 131 I with three distinct phases. The corresponding clearance half-times were 131 I contaminating the home. (authors)

SU-F-J-45: Sparing Normal Tissue with Ultra-High Dose Rate in Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Feng, Y [DCH Reg. Medical Center, Tuscaloosa, AL (United States)

2016-06-15

Purpose: To spare normal tissue by reducing the location uncertainty of a moving target, we proposed an ultra-high dose rate system and evaluated. Methods: High energy electrons generated with a linear accelerator were injected into a storage ring to be accumulated. The number of the electrons in the ring was determined based on the prescribed radiation dose. The dose was delivered within a millisecond, when an online imaging system found that the target was in the position that was consistent with that in a treatment plan. In such a short time period, the displacement of the target was negligible. The margin added to the clinical target volume (CTV) could be reduced that was evaluated by comparing of volumes between CTV and ITV in 14 cases of lung stereotactic body radiation therapy (SBRT) treatments. A design of the ultra-high dose rate system was evaluated based clinical needs and the recent developments of low energy (a few MeV) electron storage ring. Results: This design of ultra-high dose rate system was feasible based on the techniques currently available. The reduction of a target volume was significant by reducing the margin that accounted the motion of the target. ∼50% volume reduction of the internal target volume (ITV) could be achieved in lung SBRT treatments. Conclusion: With this innovation of ultra-high dose rate system, the margin of target is able to be significantly reduced. It will reduce treatment time of gating and allow precisely specified gating window to improve the accuracy of dose delivering.

Thyroid neoplasia following radiation therapy for Hodgkin's lymphoma

International Nuclear Information System (INIS)

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

1987-01-01

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

Radiation therapy of malignant melanoma: Experience with high individual treatment doses

International Nuclear Information System (INIS)

Habermalz, H.J.; Fischer, J.J.

1984-01-01

Melanoma is a complex tumor, metastasizes early both by lymphatic and blood vessels, and which may invoke a significant host ''immune,'' response. One can imagine a number of potentially useful roles for an effective radiation therapy regimen: 1. Treatment of the primary lesion. For small lesions located on the extremities, surgery may be simpler and obviate the risk of radiation failure. In other areas, e.g., head and neck, which may require more cosmetically or functionally debilitating surgery, a trial of radiation therapy may be worthwhile. 2. Preoperative radiation to the primary lesion before surgical resection in the hope of preventing tumor dissemination. 3. Prophylactic, local and regional lymph node radiation therapy. It has been popular in the past to remove malignant melanoma with wide local excision and dissection of adjacent node areas. It is still an open question whether some or any additional patients will be cured by the more vigorous local and extended treatment. Generally, those procedures have fallen into disfavor because of the associated morbidity. Presumably subclinical amounts of malignant melanoma could be sterilized with doses of radiation smaller than those necessary for bulk tumor. Wide field irradiation to the areas surrounding the primary lesion and the adjacent lymph nodes, to doses causing little morbidity, may well be worth clinical trial. 4. In combination with other forms of therapy, e.g., chemotherapy, immunotherapy, hyperthermia, to reduce the number of malignant cells in localized areas known to contain diseases. This may be particularly important prior to initiation of immunotherapy which may be much more effective in the absence of gross disease

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.

Comparison between the mechanical and radiative electron-capture processes at high energies

International Nuclear Information System (INIS)

Gonzalez, A.D.; Miraglia, J.E.

1984-01-01

The ground-state--ground-state mechanical and radiative electron-capture processes are studied at very high, but not relativistic, projectile velocities. Three-body calculations were carried out with use of the continuum distorted-wave theoretical method for both processes. Total cross sections and final-atom angular distributions were computed, and the importance of each mechanism examined. For total cross sections, the numerical results reaffirm that the radiative process is the predominant mechanism at very high projectile energies. For a given incident charge, the range of projectile energies in which the nonrelativistic radiative mechanism is the most important decreases as the target charge increases. It is found that the radiative mechanism produces a very sharp final-atom angular distribution in the forward direction. When both processes, the radiative and mechanical, give the same total cross section, the calculations show that the radiative differential cross section in the forward direction is almost 2 orders of magnitude larger than the mechanical one

Proton-minibeam radiation therapy: A proof of concept

Energy Technology Data Exchange (ETDEWEB)

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

2013-03-15

Purpose: This Monte Carlo simulation work aims at studying a new radiotherapy approach called proton-minibeam radiation therapy (pMBRT). The main objective of this proof of concept was the evaluation of the possible gain in tissue sparing, thanks to the spatial fractionation of the dose, which could be used to deposit higher and potentially curative doses in clinical cases where tissue tolerances are a limit for conventional methods. Methods: Monte Carlo simulations (GATE v.6) have been used as a method to calculate the ratio of the peak-to-valley doses (PVDR) for arrays of proton minibeams of 0.7 mm width and several center-to-center distances, at different depths in a water phantom. The beam penumbras were also evaluated as an important parameter for tissue sparing, for example, in the treatment of non-cancer diseases like epilepsy. Two proton energies were considered in this study: a clinically relevant energy (105 MeV) and a very high energy (1 GeV), to benefit from a reduced lateral scattering. For the latter case, an interlaced geometry was also evaluated. Results: Higher or similar PVDR than the ones obtained in x-rays minibeam radiation therapy were achieved in several pMBRT configurations. In addition, for the two energies studied, the beam penumbras are smaller than in the case of Gamma Knife radiosurgery. Conclusions: The high PVDR obtained for some configurations and the small penumbras in comparison with existing radiosurgery techniques, suggest a potential gain in healthy tissue sparing in this new technique. Biological studies are warranted to assess the effects of pMBRT on both normal and tumoral tissues.

An investigation of fission models for high-energy radiation transport calculations

International Nuclear Information System (INIS)

Armstrong, T.W.; Cloth, P.; Filges, D.; Neef, R.D.

1983-07-01

An investigation of high-energy fission models for use in the HETC code has been made. The validation work has been directed checking the accuracy of the high-energy radiation transport computer code HETC to investigate the appropriate model for routine calculations, particularly for spallation neutron source applications. Model calculations are given in terms of neutron production, fission fragment energy release, and residual nuclei production for high-energy protons incident on thin uranium targets. The effect of the fission models on neutron production from thick uranium targets is also shown. (orig.)

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

International Nuclear Information System (INIS)

Adam, Jean-Francois

2005-01-01

High-grade gliomas are the most frequent type of primary brain tumors in adults. Unfortunately, the management of glioblastomas is still mainly palliative and remains a difficult challenge, despite advances in brain tumor molecular biology and in some emerging therapies. Synchrotron radiation opens fields for medical imaging and radiation therapy by using monochromatic intense x-ray beams. It is now well known that angiogenesis plays a critical role in the tumor growth process and that brain perfusion is representative of the tumor mitotic activity. Synchrotron radiation quantitative computed tomography (SRCT) is one of the most accurate techniques for measuring in vivo contrast agent concentration and thus computing precise and accurate absolute values of the brain perfusion key parameters. The methodological developments of SRCT absolute brain perfusion measurements as well as their preclinical validation are detailed in this thesis. In particular, absolute cerebral volume and blood brain barrier permeability high-resolution (pixel size 2 ) parametric maps were reported. In conventional radiotherapy, the treatment of these tumors remains a delicate challenge, because the damages to the surrounding normal brain tissue limit the amount of radiation that can be delivered. One strategy to overcome this limitation is to infuse an iodinated contrast agent to the patient during the irradiation. The contrast agent accumulates in the tumor, through the broken blood brain barrier, and the irradiation is performed with kilovoltage x rays, in tomography mode, the tumor being located at the center of rotation and the beam size adjusted to the tumor dimensions. The dose enhancement results from the photoelectric effect on the heavy element and from the irradiation geometry. Synchrotron beams, providing high intensity, tunable monochromatic x rays, are ideal for this treatment. The beam properties allow the selection of monochromatic irradiation, at the optimal energy, for a

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

Some computer graphical user interfaces in radiation therapy.

Science.gov (United States)

Chow, James C L

2016-03-28

the multileaf collimator to deliver intensity modulated beams for a specific fluence map used in quality assurance or research. DOSCTP is a treatment planning system using the computed tomography images. Radiation beams (photon or electron) with different energies and field sizes produced by a linear accelerator can be placed in different positions to irradiate the tumour in the patient. DOSCTP is linked to a Monte Carlo simulation engine using the EGSnrc-based code, so that 3D dose distribution can be determined accurately for radiation therapy. Moreover, DOSCTP can be used for treatment planning of patient or small animal. PMUC is a GUI for calculation of the monitor unit based on the prescription dose of patient in photon beam radiation therapy. The calculation is based on dose corrections in changes of photon beam energy, treatment depth, field size, jaw position, beam axis, treatment distance and beam modifiers. All GUIs mentioned in this review were written either by the Microsoft Visual Basic.net or a MATLAB GUI development tool called GUIDE. In addition, all GUIs were verified and tested using measurements to ensure their accuracies were up to clinical acceptable levels for implementations.

Communication skills training for radiation therapists: preparing patients for radiation therapy.

Science.gov (United States)

Halkett, Georgia; O'Connor, Moira; Aranda, Sanchia; Jefford, Michael; Merchant, Susan; York, Debra; Miller, Lisa; Schofield, Penelope

2016-12-01

Patients sometimes present for radiation therapy with high levels of anxiety. Communication skills training may assist radiation therapists to conduct more effective consultations with patients prior to treatment planning and treatment commencement. The overall aim of our research is to examine the effectiveness of a preparatory programme 'RT Prepare' delivered by radiation therapists to reduce patient psychological distress. The purpose of this manuscript was to describe the communication skills workshops developed for radiation therapists and evaluate participants' feedback. Radiation therapists were invited to participate in two communication skills workshops run on the same day: (1) Consultation skills in radiation therapy and (2) Eliciting and responding to patients' emotional cues. Evaluation forms were completed. Radiation therapists' consultations with patients were then audio-recorded and evaluated prior to providing a follow-up workshop with participants. Nine full day workshops were held. Sixty radiation therapists participated. Positive feedback was received for both workshops with 88% or more participants agreeing or strongly agreeing with all the statements about the different components of the two workshops. Radiation therapists highlighted participating in role play with an actor, discussing issues; receiving feedback; acquiring new skills and knowledge; watching others role play and practicing with checklist were their favourite aspects of the initial workshop. The follow-up workshops provided radiation therapists with feedback on how they identified and addressed patients' psychological concerns; time spent with patients during consultations and the importance of finding private space for consultations. Communication skills training consisting of preparing patients for radiation therapy and eliciting and responding to emotional cues with follow-up workshops has the potential to improve radiation therapists' interactions with patients undergoing

Breast conservation therapy for breast cancer. Radiation oncologist's point of view

International Nuclear Information System (INIS)

Hiraoka, Masahiro; Mitsumori, Michihide; Kokubo, Masaki; Fujishiro, Satsuki

1998-01-01

The roles and problems of radiation therapy in breast conserving therapy for breast cancer were presented. The roles of radiation therapy include decrease in breast recurrence, an alternative to axillary dissection for N0 cases, and neo-adjuvant radiation therapy. On the other hand, problems associated with radiation therapy are question of using radiation therapy for all cases, complications and worsening of cosmetics, and relatively high breast recurrence rates for margin-positive cases. The concept of breast conserving therapy is to improve QOL without decreasing treatment outcomes. It is considered that we should be more concentrated on the aspects of QOL because treatment outcomes of breast conserving therapy in Japan demonstrated sofar appear excellent. (author)

Brachial Plexus-Associated Neuropathy After High-Dose Radiation Therapy for Head-and-Neck Cancer

International Nuclear Information System (INIS)

Chen, Allen M.; Hall, William H.; Li, Judy; Beckett, Laurel; Farwell, D. Gregory; Lau, Derick H.; Purdy, James A.

2012-01-01

Purpose: To identify clinical and treatment-related predictors of brachial plexus–associated neuropathies after radiation therapy for head-and-neck cancer. Methods and Materials: Three hundred thirty patients who had previously completed radiation therapy for head-and-neck cancer were prospectively screened using a standardized instrument for symptoms of neuropathy thought to be related to brachial plexus injury. All patients were disease-free at the time of screening. The median time from completion of radiation therapy was 56 months (range, 6–135 months). One-hundred fifty-five patients (47%) were treated by definitive radiation therapy, and 175 (53%) were treated postoperatively. Radiation doses ranged from 50 to 74 Gy (median, 66 Gy). Intensity-modulated radiation therapy was used in 62% of cases, and 133 patients (40%) received concurrent chemotherapy. Results: Forty patients (12%) reported neuropathic symptoms, with the most common being ipsilateral pain (50%), numbness/tingling (40%), motor weakness, and/or muscle atrophy (25%). When patients with <5 years of follow-up were excluded, the rate of positive symptoms increased to 22%. On univariate analysis, the following factors were significantly associated with brachial plexus symptoms: prior neck dissection (p = 0.01), concurrent chemotherapy (p = 0.01), and radiation maximum dose (p < 0.001). Cox regression analysis confirmed that both neck dissection (p < 0.001) and radiation maximum dose (p < 0.001) were independently predictive of symptoms. Conclusion: The incidence of brachial plexus–associated neuropathies after radiation therapy for head-and-neck cancer may be underreported. In view of the dose–response relationship identified, limiting radiation dose to the brachial plexus should be considered when possible.

High energy protons application for radiotherapy of the esophagus affected with cancer

International Nuclear Information System (INIS)

Ruderman, A.I.; Astrakhan, B.V.; Kulakov, G.A.; Makarova, G.V.; Zhuravleva, N.T.

1975-01-01

As in radiation therapy of tumours located elsewhere, local radiation treatment of an esophagus tumour is often aggravated by the development, after some time, of a trophic ulcer as a result of decreased regenerative ability of the irradiated sound tissues and also of newly formed hystostructures which have replaced the destroyed tumorous tissue. It has been established that the number of complications increases with the total focal dose, but at the same time (up to a certain point) the number of local curings increases as well. Some promise was shown by high-energy protons with their physical advantages unique for radiation therapy, such as the strictly controlled free path length of particles in the tissues, the presence of the Bragg peak, the absence of lateral scattering, i.e. features which permit of a high dose in the target with a minimum injury to the sound tissues surrounding the tumour. Proton therapy of esophagus cancer was carried out by two techniques, static and shuttle-rotary. The results of proton therapy of esophagus cancer indicate that the use of high-energy protons for treating esophagus cancer holds promise

Radiation therapy in old patients. Side effects and results of radiation therapy in old patients

International Nuclear Information System (INIS)

Geinitz, H.; Zimmermann, F.B.; Molls, M.

1999-01-01

Background: Despite a growing number of elderly patients receiving radiation therapy little is known about side effects and outcome of irradiation in this section of the population. Methods: In a review article epidemiologic data, aspects of radiation-biology as well as side effects and outcome of radiation therapy of elderly patients are discussed. Results: Cancer incidence rises with age and is exceeding 3.5% for males older than 85 years. With a life expectancy of more than 4 years, curative therapy is indicated even at this age. Furthermore, several retrospective studies indicate that local control and disease-Specific survival after radiation therapy of elderly patients is comparable with that of younger persons. The exception contains elderly patients with grade-III to IV gliomas or with rectal carcinoma who show a reduced survival which is perhaps caused by less aggressive combined treatment (tumor resection). Although some biological and molecular data indicate a rise in radiation sensitivity with growing age like the reduction of the capacity of some DNA-repair enzymes, there is no convincing evidence in animal studies or in retrospective clinical studies that radiation therapy is generally less well tolerated by older individuals. Some age-depending differences in organ toxicities are described in 3 large studies, which evaluate the data of patients who were enrolled in different EORTC-trials: Older patients suffer more of functional mucositis in case of radiation therapy to the head and neck, they have an increased weight loss and a higher frequency of late esophageal damage when irradiated in the thorax, and they show a higher prevalence of sexual dysfunction when treated with radiation therapy to the pelvis. On the other hand younger patients suffer more from acute toxicity like skin damage, nausea, and deterioration of the performance status during pelvic radiotherapy. When discussing the dose intensity of radiation therapy concomitant disease which

Effect of Photon Beam Energy, Gold Nanoparticle Size and Concentration on the Dose Enhancement in Radiation Therapy

Directory of Open Access Journals (Sweden)

Nahideh Gharehaghaji

2013-02-01

Full Text Available Introduction: Gold nanoparticles have been used as radiation dose enhancing materials in recent investigations. In the current study, dose enhancement effect of gold nanoparticles on tumor cells was evaluated using Monte Carlo (MC simulation. Methods: We used MCNPX code for MC modeling in the current study. A water phantom and a tumor region with a size of 1×1×1 cm3 loaded with gold nanoparticles were simulated. The macroscopic dose enhancement factor was calculated for gold nanoparticles with sizes of 30, 50, and 100 nm. Also, we simulated different photon beams including mono-energetic beams (50-120 keV, a Cobalt-60 beam, 6 & 18 MV photon beams of a conventional linear accelerator. Results: We found a dose enhancement factor (DEF of from 1.4 to 3.7 for monoenergetic kilovoltage beams, while the DEFs for megavoltage beams were negligible and less than 3% for all GNP sizes and concentrations. The optimum energy for higher DEF was found to be the 90 keV monoenergetic beam. The effect of GNP size was not considerable, but the GNP concentration had a substantial impact on achieved DEF in GNP-based radiation therapy. Conclusion: The results were in close agreement with some previous studies considering the effect of photon energy and GNP concentration on observed DEF. Application of GNP-based radiation therapy using kilovoltage beams is recommended.

Radiation therapy

International Nuclear Information System (INIS)

Peschel, R.E; Fisher, J.J.

1986-01-01

The new insights and controversies concerning the radiobiological properties of malignant melanoma and how these relate to new clinical approaches are reviewed. The recent clinical experience with large individual fraction sizes is analyzed. The treatment of malignant melanoma in certain specialized sites is also described. An attempt is made to place in perspective the usefulness of radiation therapy in the treatment of this complex disease. Finally, certain new applications for radiation therapy both alone and in combustion with other treatment modalities are proposed that may ultimately prove appropriate for clinical trials

Ultrasound-mediated microbubble enhancement of radiation therapy studied using three-dimensional high-frequency power Doppler ultrasound.

Science.gov (United States)

Kwok, Sheldon J J; El Kaffas, Ahmed; Lai, Priscilla; Al Mahrouki, Azza; Lee, Justin; Iradji, Sara; Tran, William Tyler; Giles, Anoja; Czarnota, Gregory J

2013-11-01

Tumor responses to high-dose (>8 Gy) radiation therapy are tightly connected to endothelial cell death. In the study described here, we investigated whether ultrasound-activated microbubbles can locally enhance tumor response to radiation treatments of 2 and 8 Gy by mechanically perturbing the endothelial lining of tumors. We evaluated vascular changes resulting from combined microbubble and radiation treatments using high-frequency 3-D power Doppler ultrasound in a breast cancer xenograft model. We compared treatment effects and monitored vasculature damage 3 hours, 24 hours and 7 days after treatment delivery. Mice treated with 2 Gy radiation and ultrasound-activated microbubbles exhibited a decrease in vascular index to 48 ± 10% at 24 hours, whereas vascular indices of mice treated with 2 Gy radiation alone or microbubbles alone were relatively unchanged at 95 ± 14% and 78 ± 14%, respectively. These results suggest that ultrasound-activated microbubbles enhance the effects of 2 Gy radiation through a synergistic mechanism, resulting in alterations of tumor blood flow. This novel therapy may potentiate lower radiation doses to preferentially target endothelial cells, thus reducing effects on neighboring normal tissue and increasing the efficacy of cancer treatments. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

A study of build-up effects in high-energy radiation fields using a TEPC

Energy Technology Data Exchange (ETDEWEB)

Hoefert, M; Stevenson, G R [CERN, European Laboratory for Particle Physics, Geneva (Switzerland); Aroua, A [IAR, Institute for Applied Radiophysics, Lausanne (Switzerland); Sannikov, A V [IHEP, Institute for High-Energy Physics, Protvino (Russian Federation)

1995-09-04

A dose of 2 mSv close to the body surface of a pregnant woman is considered by ICRP to assure a dose limit of 1 mSv to the foetus. Such an assumption depends on the energy spectrum and composition of the external radiation field and it was tested in radiation fields containing high-energy particles similar to those found around high-energy particle accelerators and in air-craft. Measurements of dose and dose equivalent were performed as a function of wall thickness using a tissue-equivalent proportional counter (TEPC) in radiation fields at the CERN-EU Reference Radiation Facility. Results are presented both with respect to integral quantities and event size spectra. The decrease in dose and dose equivalent at a depth equivalent to that of the foetus was typically 10% in a high-energy stray radiation field and in the case of PuBe source neutrons amounted to only 30%. It is concluded that it would be prudent under such exposure conditions to limit the dose of a pregnant woman to 1 mSv in order to assure that the dose to the foetus remains below the same limit. (author)

A study of build-up effects in high-energy radiation fields using a TEPC

International Nuclear Information System (INIS)

Hoefert, M.; Stevenson, G.R.; Aroua, A.; Sannikov, A.V.

1995-01-01

A dose of 2 mSv close to the body surface of a pregnant woman is considered by ICRP to assure a dose limit of 1 mSv to the foetus. Such an assumption depends on the energy spectrum and composition of the external radiation field and it was tested in radiation fields containing high-energy particles similar to those found around high-energy particle accelerators and in air-craft. Measurements of dose and dose equivalent were performed as a function of wall thickness using a tissue-equivalent proportional counter (TEPC) in radiation fields at the CERN-EU Reference Radiation Facility. Results are presented both with respect to integral quantities and event size spectra. The decrease in dose and dose equivalent at a depth equivalent to that of the foetus was typically 10% in a high-energy stray radiation field and in the case of PuBe source neutrons amounted to only 30%. It is concluded that it would be prudent under such exposure conditions to limit the dose of a pregnant woman to 1 mSv in order to assure that the dose to the foetus remains below the same limit. (author)

Characteristics of silicon diodes as patient dosemeters in external radiation therapy

International Nuclear Information System (INIS)

Nilsson, B.; Sorcini, B.

1988-01-01

Silicon diodes connected to an integrating instrument that are used to measure the entrance dose on patients undergoing radiation therapy have been investigated with special emphasis on practical clinical aspects. The variation of the diode response for different photon qualities with different field sizes and different irradiation situations including oblique fields, wedges, blocking filters giving different electron contamination have been measured. The diode response for the different situations met in clinical practice when using various electron energies have also been examined. The results from measurements for patients treated with high energy are presented. The study has shown that if the mean value of all measured entrance doses with the diode on a patient differ more than ±3% from the presented absorbed dose for 60 Co gamma radiation, a correction of the given dose should be made. The corresponding figure for high energy X-rays is ±5%. 23 refs.; 6 figs.; 5 tabs

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)

Whole-brain radiation therapy for brain metastases: detrimental or beneficial?

International Nuclear Information System (INIS)

Gemici, Cengiz; Yaprak, Gokhan

2015-01-01

Stereotactic radiosurgery is frequently used, either alone or together with whole-brain radiation therapy to treat brain metastases from solid tumors. Certain experts and radiation oncology groups have proposed replacing whole-brain radiation therapy with stereotactic radiosurgery alone for the management of brain metastases. Although randomized trials have favored adding whole-brain radiation therapy to stereotactic radiosurgery for most end points, a recent meta-analysis demonstrated a survival disadvantage for patients treated with whole-brain radiation therapy and stereotactic radiosurgery compared with patients treated with stereotactic radiosurgery alone. However the apparent detrimental effect of adding whole-brain radiation therapy to stereotactic radiosurgery reported in this meta-analysis may be the result of inhomogeneous distribution of the patients with respect to tumor histologies, molecular histologic subtypes, and extracranial tumor stages between the groups rather than a real effect. Unfortunately, soon after this meta-analysis was published, even as an abstract, use of whole-brain radiation therapy in managing brain metastases has become controversial among radiation oncologists. The American Society of Radiation Oncology recently recommended, in their “Choose Wisely” campaign, against routinely adding whole-brain radiation therapy to stereotactic radiosurgery to treat brain metastases. However, this situation creates conflict for radiation oncologists who believe that there are enough high level of evidence for the effectiveness of whole-brain radiation therapy in the treatment of brain metastases

Medulloblastoma: Conventional Radiation Therapy in Comparison to Chemo Radiation Therapy in The Post-operative Treatment of High-Risk Patients

International Nuclear Information System (INIS)

Abd El-Aal, H.H.; Mokhtar, M.M.; Habib, E.E.; El-Kashef, A.T.; Fahmy, E.S.

2005-01-01

The aim of this study is to assess treatment results of 48 pediatric high-risk medulloblastoma cases that were treated by surgery, radiotherapy with or without chemotherapy. The impact of adjuvant combination chemotherapy on treatment results will be assessed. Forty-eight cases of pediatric high-risk medulloblastoma treated from July 2001 to July 2004 were randomized into two groups. The first (group I) included 21 patients who received postoperative craniospinal radiation therapy (36 Gy + boost 20 Gy to the posterior fossa). The second (group II) included 27 cases who received postoperative combination cranio-spinal radiation therapy (with the same dose as the first group) and chemotherapy (vincristine, etoposide, cisplatin). Both groups were compared as regards overall survival (OS), disease free survival (DFS), response rate and treatment toxicity. In-group I, complete remission (CR) was achieved in 71.4% of the cases; partial remission (PR) in 14.3% of the patients; stationary disease (SD) in 14.3% and none of the cases suffered from progressive disease. The three year OS was 69.5% and the three-year OFS was 61.3%. In-group II, CR was achieved in 59.3% of the cases; PR in 3.7%; SO in 3.7% and PO in 37.3% of the cases. The three-year OS was 48.4% and the 3-year OFS was 48.9%. Regarding acute treatment toxicity in group I, nine patients (31.5%) developed grade I myelo-suppression and seven cases (24.5%) developed grade II myelo-suppression with three to five days treatment interruption. Whereas in group II, 13 patients (45.5%) developed grade I myelosuppression and seven cases (24.5%) developed grade II myelo-suppression requiring interruption of treatment for a period ranging from five to seven days with spontaneous recovery. In group I no other acute toxicity was recognized, whereas in group II other toxicities related to chemotherapy were noticed. For example, three patients (II %) developed peripheral neuritis during the course of treatment and two patients

Investigation of Radiation Protection Methodologies for Radiation Therapy Shielding Using Monte Carlo Simulation and Measurement

Science.gov (United States)

Tanny, Sean

The advent of high-energy linear accelerators for dedicated medical use in the 1950's by Henry Kaplan and the Stanford University physics department began a revolution in radiation oncology. Today, linear accelerators are the standard of care for modern radiation therapy and can generate high-energy beams that can produce tens of Gy per minute at isocenter. This creates a need for a large amount of shielding material to properly protect members of the public and hospital staff. Standardized vault designs and guidance on shielding properties of various materials are provided by the National Council on Radiation Protection (NCRP) Report 151. However, physicists are seeking ways to minimize the footprint and volume of shielding material needed which leads to the use of non-standard vault configurations and less-studied materials, such as high-density concrete. The University of Toledo Dana Cancer Center has utilized both of these methods to minimize the cost and spatial footprint of the requisite radiation shielding. To ensure a safe work environment, computer simulations were performed to verify the attenuation properties and shielding workloads produced by a variety of situations where standard recommendations and guidance documents were insufficient. This project studies two areas of concern that are not addressed by NCRP 151, the radiation shielding workload for the vault door with a non-standard design, and the attenuation properties of high-density concrete for both photon and neutron radiation. Simulations have been performed using a Monte-Carlo code produced by the Los Alamos National Lab (LANL), Monte Carlo Neutrons, Photons 5 (MCNP5). Measurements have been performed using a shielding test port designed into the maze of the Varian Edge treatment vault.

Experimental perforating injury with high energy electrons to inhibit intraocular proliferation

International Nuclear Information System (INIS)

Velikay, M.; Binder, S.; Stolba, U.; Wedrich, AJ.; Datlinger, P.; Handl-Zeller, L.

1994-01-01

Since 1980, the fibroblast model creating experimental proliferative vitreoretinopathy has been used to evaluate the antiproliferative effect of various drugs. In previous studies radiation therapy was found to reduce effectively intraocular proliferation in this model. We therefore investigated the effect of high energy electrons in a standard perforating injury model creating a traumatic proliferative vitreoretinopathy. In 36 eyes we performed a 8 mm pars plana incision and injected 0.4 ml of 80% fibronection solution intravitreally. Ten rabbits (20 eyes) received radiation therapy with a Betatron accelerator in a total dosage of 3000 cGy to each eye divided into 10 single fractions starting on the first post-operative day. Maximum concentration of the dose was focused to the posterior vitreous. The other 9 rabbits, 18 eyes, served as control. In our perforating injury model we observed a reduction of retinal detachment rate of 72% in the controls to 55% in the treated group. The effect of radiation therapy with high energy electrons and total dosage of 3000 cGy was not statistically significant in experimental traumatic proliferative vitreoretinopathy. (au) (12 refs.)

Radiation protection of the operation of accelerator facilities. On high energy proton and electron accelerators

International Nuclear Information System (INIS)

Kondo, Kenjiro

1997-01-01

Problems in the radiation protection raised by accelerated particles with energy higher than several hundreds MeV in strong accelerator facilities were discussed in comparison with those with lower energy in middle- and small-scale facilities. The characteristics in the protection in such strong accelerator facilities are derived from the qualitative changes in the interaction between the high energy particles and materials and from quantitative one due to the beam strength. In the former which is dependent on the emitting mechanism of the radiation, neutron with broad energy spectrum and muon are important in the protection, and in the latter, levels of radiation and radioactivity which are proportional to the beam strength are important. The author described details of the interaction between high energy particles and materials: leading to the conclusion that in the electron accelerator facilities, shielding against high energy-blemsstrahlung radiation and -neutron is important and in the proton acceleration, shielding against neutron is important. The characteristics of the radiation field in the strong accelerator facilities: among neutron, ionized particles and electromagnetic wave, neutron is most important in shielding since it has small cross sections relative to other two. Considerations for neutron are necessary in the management of exposure. Multiplicity of radionuclides produced: which is a result of nuclear spallation reaction due to high energy particles, especially to proton. Radioactivation of the accelerator equipment is a serious problem. Other problems: the interlock systems, radiation protection for experimenters and maintenance of the equipment by remote systems. (K.H.). 11 refs

Thyroid dysfunction after radiation therapy to the neck

International Nuclear Information System (INIS)

Soejima, Toshinori; Hirota, Saeko; Obayashi, Kayoko; Takada, Yoshiki; Kimura, Shuji; Yoshida, Shoji.

1993-01-01

The effects of radiation on the thyroid were investigated in 102 patients treated by radiation therapy to the neck. All patients had radiation ports which included the thyroid gland. Serum thyroid stimulating hormone (TSH) levels were elevated in 41 cases and the cumulative elevation rate was 52.1% in 5 years. The high frequency of elevated serum TSH levels observed in patients whose thyroid glands were included within the radiation fields (74.1%) was statistically significant compared to those whose thyroid glands were only partially included (23.4%). Among the patients whose entire thyroid glands were included within the radiation field, combination with chemotherapy increased the frequency of elevated serum TSH levels, but the increase was not statistically significant. Among 36 laryngeal cancer patients treated by only radiation therapy through a portal encompassing part of the thyroid, 4 (14%) were found to have elevated serum TSH levels. We advocate routine monitoring of thyroid functions after radiation therapy to the neck. (author)

Impact of [F-18]-fluoro-ethyl-tyrosine PET imaging on target definition for radiation therapy of high-grade glioma

DEFF Research Database (Denmark)

af Rosenschold, Per Munck; Costa, Junia; Engelholm, Svend Aage

2015-01-01

BACKGROUND: We sought to assess the impact of amino-acid (18)F-fluoro-ethyl-tyrosine (FET) positron emission tomography (PET) on the volumetric target definition for radiation therapy of high-grade glioma versus the current standard using MRI alone. Specifically, we investigated the influence....... Patients with grade IV glioma were found to be the primary candidates for PET-guided radiation therapy planning....

Activities of the Radiation Shielding Information Center and a report on codes/data for high energy radiation transport

International Nuclear Information System (INIS)

Roussin, R.W.

1993-01-01

From the very early days in its history Radiation Shielding Information Center (RSIC) has been involved with high energy radiation transport. The National Aeronautics and Space Administration was an early sponsor of RSIC until the completion of the Apollo Moon Exploration Program. In addition, the intranuclear cascade work of Bertini at Oak Ridge National Laboratory provided valuable resources which were made available through RSIC. Over the years, RSIC has had interactions with many of the developers of high energy radiation transport computing technology and data libraries and has been able to collect and disseminate this technology. The current status of this technology will be reviewed and prospects for new advancements will be examined

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

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.

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).

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.

Design of radiation shielding for the proton therapy facility at the National Cancer Center in Korea

International Nuclear Information System (INIS)

Kim, J. W.; Kwon, J. W.; Lee, J.

2005-01-01

The design of radiation shielding was evaluated for a proton therapy facility being established at the National Cancer Center in Korea. The proton beam energy from a 230 MeV cyclotron is varied for therapy using a graphite target. This energy variation process produces high radiation and thus thick shielding walls surround the region. The evaluation was first carried out using analytical expressions at selected locations. Further detailed evaluations have been performed using the Monte Carlo method. Dose equivalent values were calculated to be compared with analytical results. The analytical method generally yielded more conservative values. With consideration of adequate occupancy factors annual dose equivalent rates are kept -1 in all areas. Construction of the building is expected to be completed near the end of 2004 and the installation of therapy equipments will begin a few months later. (authors)

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.

Effect of high linear energy transfer radiation on biological membranes

International Nuclear Information System (INIS)

Choudhary, D.; Srivastava, M.; Kale, R.K.; Sarma, A.

1998-01-01

Cellular membranes are vital elements, and their integrity is extremely essential for the viability of the cells. We studied the effects of high linear energy transfer (LET) radiation on the membranes. Rabbit erythrocytes (1 x 10 7 cells/ml) and microsomes (0.6 mg protein/ml) prepared from liver of rats were irradiated with 7 Li ions of energy 6.42 MeV/u and 16 O ions of energy 4.25 MeV/u having maximum LET values of 354 keV/μm and 1130 keV/μm, respectively. 7 Li- and 16 O-induced microsomal lipid peroxidation was found to increase with fluence. The 16 O ions were more effective than 7 Li ions, which could be due to the denser energy distribution in the track and the yield of free radicals. These findings suggested that the biological membranes could be peroxidized on exposure to high-LET radiation. Inhibition of the lipid peroxidation was observed in the presence of a membrane-active drug, chlorpromazine (CPZ), which could be due to scavenging of free radicals (mainly HO. and ROO.), electron donation, and hydrogen transfer reactions. The 7 Li and 16 O ions also induced hemolysis in erythrocytes. The extent of hemolysis was found to be a function of time and fluence, and showed a characteristic sigmoidal pattern. The 16 O ions were more effective in the lower fluence range than 7 Li ions. These results were compared with lipid peroxidation and hemolysis induced by gamma-radiation. (orig.)

Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy

International Nuclear Information System (INIS)

Chu, Sung Sil; Suh, Chang Ok; Kim, Gwi Eon

2002-01-01

High energy photon beams from medical linear accelerators produce large scattered radiation by various components of the treatment head, collimator and walls or objects in the treatment room including the patient. These scattered radiation do not provide therapeutic dose and are considered a hazard from the radiation safety perspective. Scattered dose of therapeutic high energy radiation beams are contributed significant unwanted dose to the patient. ICRP take the position that a dose of 500mGy may cause abortion at any stage of pregnancy and that radiation detriment to the fetus includes risk of mental retardation with a possible threshold in the dose response relationship around 100 mGy for the gestational period. The ICRP principle of As Low As Reasonably Achievable (ALARA) was recommended for protection of occupation upon the linear no-threshold dose response hypothesis for cancer induction. We suggest this ALARA principle be applied to the fetus and testicle in therapeutic treatment. Radiation dose outside a photon treatment filed is mostly due to scattered photons . This scattered dose is a function of the distance from the beam edge, treatment geometry, primary photon energy, and depth in the patient. The need for effective shielding of the fetus and testicle is reinforced when young patients are treated with external beam radiation therapy and then shielding designed to reduce the scattered photon dose to normal organs have to considered. Irradiation was performed in phantom using high energy photon beams produced by a Varian 2100C/D medical linear accelerator (Varian Oncology Systems, Polo Alto, CA) located at the Yonsei Cancer Center. The composite phantom used was comprised of a commercially available anthropomorphic Rando phantom (Phantom Laboratory Inc., Salem, YN) and a rectangular solid polystyrene phantom of dimensions 30cm x 30cm x 20cm. The anthropomorphic Rando phantom represents an average man made from tissue equivalent materials that is

Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Chu, Sung Sil; Suh, Chang Ok; Kim, Gwi Eon [Yonsei Univ., Seoul (Korea, Republic of)

2002-03-15

High energy photon beams from medical linear accelerators produce large scattered radiation by various components of the treatment head, collimator and walls or objects in the treatment room including the patient. These scattered radiation do not provide therapeutic dose and are considered a hazard from the radiation safety perspective. Scattered dose of therapeutic high energy radiation beams are contributed significant unwanted dose to the patient. ICRP take the position that a dose of 500mGy may cause abortion at any stage of pregnancy and that radiation detriment to the fetus includes risk of mental retardation with a possible threshold in the dose response relationship around 100 mGy for the gestational period. The ICRP principle of As Low As Reasonably Achievable (ALARA) was recommended for protection of occupation upon the linear no-threshold dose response hypothesis for cancer induction. We suggest this ALARA principle be applied to the fetus and testicle in therapeutic treatment. Radiation dose outside a photon treatment filed is mostly due to scattered photons . This scattered dose is a function of the distance from the beam edge, treatment geometry, primary photon energy, and depth in the patient. The need for effective shielding of the fetus and testicle is reinforced when young patients are treated with external beam radiation therapy and then shielding designed to reduce the scattered photon dose to normal organs have to considered. Irradiation was performed in phantom using high energy photon beams produced by a Varian 2100C/D medical linear accelerator (Varian Oncology Systems, Polo Alto, CA) located at the Yonsei Cancer Center. The composite phantom used was comprised of a commercially available anthropomorphic Rando phantom (Phantom Laboratory Inc., Salem, YN) and a rectangular solid polystyrene phantom of dimensions 30cm x 30cm x 20cm. The anthropomorphic Rando phantom represents an average man made from tissue equivalent materials that is

21 CFR 892.5710 - Radiation therapy beam-shaping block.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiation therapy beam-shaping block. 892.5710 Section 892.5710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... block. (a) Identification. A radiation therapy beam-shaping block is a device made of a highly...

Local Control With 21-Gy Radiation Therapy for High-Risk Neuroblastoma

International Nuclear Information System (INIS)

Casey, Dana L.; Kushner, Brian H.; Cheung, Nai-Kong V.; Modak, Shakeel; LaQuaglia, Michael P.; Wolden, Suzanne L.

2016-01-01

Purpose: To evaluate local control after 21-Gy radiation therapy (RT) to the primary site in patients with high-risk neuroblastoma. Methods and Materials: After receiving dose-intensive chemotherapy and gross total resection (GTR), 246 patients (aged 1.2-17.9 years, median 4.0 years) with high-risk neuroblastoma underwent RT to the primary site at Memorial Sloan Kettering from 2000 to 2014. Radiation therapy consisted of 21 Gy in twice-daily fractions of 1.5 Gy each. Local failure (LF) was correlated with biologic prognostic factors and clinical findings at the time of diagnosis and start of RT. Results: Median follow-up of surviving patients was 6.4 years. Cumulative incidence of LF was 7.1% at 2 years after RT and 9.8% at 5 years after RT. The isolated LF rate was 3.0%. Eighty-six percent of all local failures were within the RT field. Local control was worse in patients who required more than 1 surgical resection to achieve GTR (22.4% vs 8.3%, P=.01). There was also a trend toward inferior local control with MYCN-amplified tumors or serum lactate dehydrogenase ≥1500 U/L (P=.09 and P=.06, respectively). Conclusion: After intensive chemotherapy and maximal surgical debulking, hyperfractionated RT with 21 Gy in high-risk neuroblastoma results in excellent local control. Given the young patient age, concern for late effects, and local control >90%, dose reduction may be appropriate for patients without MYCN amplification who achieve GTR.

Local Control With 21-Gy Radiation Therapy for High-Risk Neuroblastoma

Energy Technology Data Exchange (ETDEWEB)

Casey, Dana L. [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Kushner, Brian H.; Cheung, Nai-Kong V.; Modak, Shakeel [Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); LaQuaglia, Michael P. [Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Wolden, Suzanne L., E-mail: woldens@mskcc.org [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States)

2016-10-01

Purpose: To evaluate local control after 21-Gy radiation therapy (RT) to the primary site in patients with high-risk neuroblastoma. Methods and Materials: After receiving dose-intensive chemotherapy and gross total resection (GTR), 246 patients (aged 1.2-17.9 years, median 4.0 years) with high-risk neuroblastoma underwent RT to the primary site at Memorial Sloan Kettering from 2000 to 2014. Radiation therapy consisted of 21 Gy in twice-daily fractions of 1.5 Gy each. Local failure (LF) was correlated with biologic prognostic factors and clinical findings at the time of diagnosis and start of RT. Results: Median follow-up of surviving patients was 6.4 years. Cumulative incidence of LF was 7.1% at 2 years after RT and 9.8% at 5 years after RT. The isolated LF rate was 3.0%. Eighty-six percent of all local failures were within the RT field. Local control was worse in patients who required more than 1 surgical resection to achieve GTR (22.4% vs 8.3%, P=.01). There was also a trend toward inferior local control with MYCN-amplified tumors or serum lactate dehydrogenase ≥1500 U/L (P=.09 and P=.06, respectively). Conclusion: After intensive chemotherapy and maximal surgical debulking, hyperfractionated RT with 21 Gy in high-risk neuroblastoma results in excellent local control. Given the young patient age, concern for late effects, and local control >90%, dose reduction may be appropriate for patients without MYCN amplification who achieve GTR.

Technological progress in radiation therapy for brain tumors

LENUS (Irish Health Repository)

Vernimmen, Frederik Jozef

2014-01-01

To achieve a good therapeutic ratio the radiation dose to the tumor should be as high as possible with the lowest possible dose to the surrounding normal tissue. This is especially the case for brain tumors. Technological ad- vancements in diagnostic imaging, dose calculations, and radiation delivery systems, combined with a better un- derstanding of the pathophysiology of brain tumors have led to improvements in the therapeutic results. The widely used technology of delivering 3-D conformal therapy with photon beams (gamma rays) produced by Li-near Accelerators has progressed into the use of Intensity modulated radiation therapy (IMRT). Particle beams have been used for several decades for radiotherapy because of their favorable depth dose characteristics. The introduction of clinically dedicated proton beam therapy facilities has improved the access for cancer patients to this treatment. Proton therapy is of particular interest for pediatric malignancies. These technical improvements are further enhanced by the evolution in tumor physiology imaging which allows for improved delineation of the tumor. This in turn opens the potential to adjust the radiation dose to maximize the radiobiological effects. The advances in both imaging and radiation therapy delivery will be discussed.

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)

Energy and intensity modulated radiation therapy with electrons

OpenAIRE

Olofsson, Lennart

2005-01-01

In recent years intensity modulated radiation therapy with photons (xIMRT) has gained attention due to its ability to reduce the dose in the tissues close to the tumour volume. However, this technique also results in a large low dose volume. Electron IMRT (eIMRT) has the potential to reduce the integral dose to the patient due to the dose fall off in the electron depth dose curves. This dose fall off makes it possible to modulate the dose distribution in the direction of the beam by selecting...

Control of the radiation environment and the worker in high-energy facilities

International Nuclear Information System (INIS)

Stevenson, G.R.

1993-01-01

The philosophy behind the prediction, measurement, monitoring and limitation by access control of the radiation hazard in high-energy accelerator facilities is compared with that which could be employed for controlling similar hazards due to cosmic radiation in civil aircraft flights. Special mention is made of computer simulations of the radiation environment as a means of predicting necessary control measures, of the reliability and integration of radiation measuring devices into control procedures and of the relevance of different access control procedures. (author)

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

Radiation effects on integrated circuits used in high energy research

International Nuclear Information System (INIS)

Kanofsky, A.S.; Yost, B.; Farr, W.

1990-01-01

The authors report here on radiation effects on two amplifiers used in high energy experiments. These are standard devices that are produced by LeCroy. They describe each of the devices and the experimental techniques. Finally, they present and discuss the results of the measurements. 5 figs

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.

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

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

Radiation Therapy Side Effects

Science.gov (United States)

Radiation therapy has side effects because it not only kills or slows the growth of cancer cells, it can also affect nearby healthy cells. Many people who get radiation therapy experience fatigue. Other side effects depend on the part of the body that is being treated. Learn more about possible side effects.

The Effect of High Dose Radioiodine Therapy on Formation of Radiation Retinopathy During Thyroid Cancer Treatment

Directory of Open Access Journals (Sweden)

Tülay Kaçar Güvel

2014-10-01

Full Text Available Objective: Non-thyroidal complication of high-dose radioiodine therapy for thyroid carcinoma might cause salivary and lacrimal gland dysfunction, which may be transient or permanent in a dose-dependent manner. However, radiation retinopathy complicating 131I therapy, has not been previously well characterized. The aim of this study was to evaluate the extent of retinal damage among patients who had received high doses of radioiodine treatment. Methods: Forty eyes of 20 patients (3 male, 17 female who received 250-1000 mCi during 131I therapy and on ophthalmological follow up for a year after the last treatment were included in the study. Mean age of the study group was 50 years (range 25-70 years. In ophthalmologic examination, visual acuity was measured in order to determine visual loss. Intraocular pressure was measured in all the patients. Then lens examination was carried out with slit lamp biomicroscopy in order to investigate cataract or partial lens opacities. Fundus observation was carried out through the dilated pupil with slit lamp biomicroscopy using 90 D noncontact lens. Result: The best corrected visual aquity with Snellen chart was found as 1.0 in 36 eyes (90% and between 0.6 and 0.9 (10% in 4 eyes (10%. At the biomicroscopic fundus examination, retinal hemorrhage consistent with radiation retinopathy, microaneurysm, microinfarction, edema or exudation, vitreus hemorrhage, partial or total optical disc pallor indicating papillopathy in the optic disc were not observed in any of the eyes. Conclusion: This result indicates that there is not any significant correlation between repeated high-dose radioiodine therapy and radiation retinopathy in differentiated thyroid carcinomas. Even though there is not a significant restriction in use of higher doses of radioiodine therapy in differentiated thyroid carcinoma, more extensive studies are needed in order to obtain more accurate data on possible occurrence of retinopathy.

Internal Radiation Therapy for Cancer

Science.gov (United States)

When getting internal radiation therapy, a source of radiation is put inside your body, in either liquid or solid form. It can be used treat different kinds of cancer, including thyroid, head and neck, breast, cervix, prostate, and eye. Learn more about how what to expect when getting internal radiation therapy.

Use of high energy radiation in decomposition and removal of organic water pollutants

International Nuclear Information System (INIS)

Toelgyessy, P.

1990-01-01

The present review deals with the radiation chemistry of dilute aqueous solutions of organic substances emphasizing the possibility of use of high energy radiation in waste water treatment. Effects of radiation on biodegradability, toxicity to water organisms and changes in molecules of solutes showing resistance to biochemical degradation and toxicity to water organisms are discussed. (author) 31 refs

High-voltage therapy of carcinoma of the prostate

International Nuclear Information System (INIS)

Schnorr, D.; Kelly, L.U.; Guddat, H.M.; Schubert, J.; Gorski, J.; Schorcht, J.; Mau, S.; Wehnert, J.; Medizinische Akademie, Dresden

1983-01-01

High-voltage therapy is becoming increasingly important as a form of individual differential therapy of carcinoma of the prostate. Around 40% of all patients with a diagnosis of carcinoma of the prostate can be treated with high-voltage therapy. The precondition is the absence of bone and soft tissue metastases and of juxtaregional lymph node metastases. Individual carcinoma therapy is based on pre therapeutic tumor classification according to the TNM system. The 5-year survival rates are presented from a retrospective study carried out using primary radiation monotherapy and a combined hormone and radiation therapy; these figures were calculated by the life-table method. The study revealed no significant differences between the two forms of therapy as regards 5-year survival rates. The 5-year survival rates of all patients of the classifications T 0 -T 3 N/sub x/-N 2 M 0 irradiated (n: 198) (72% +- 11% for hormone plus radiation therapy and 74% +- 11% for radiation monotherapy) did not differ greatly from those of a normal male population of the same age (77%). High-voltage therapy of carcinoma of the prostate can thus be classified as a curative method of treatment. (author)

Higher energy: is it necessary, is it worth the cost for radiation oncology?

Science.gov (United States)

Das, I J; Kase, K R

1992-01-01

The physical characteristics of the interactions of megavoltage photons and electrons with matter provide distinct advantages, relative to low-energy (orthovoltage) x rays, that lead to better radiation dose distributions in patients. Use of these high-energy radiations has resulted in better patient care, which has been reflected in improved radiation treatment outcome in recent years. But, as the desire for higher energy radiation beams increases, it becomes important to determine whether the physical characteristics that make megavoltage beams beneficial continue to provide a net advantage. It is demonstrated that, in fact, there is an energy range from 4 to 15 MV for photons and 4 to 20 MeV for electrons that is optimally suited for the treatment of cancer in humans. Radiation beams that exceed these maximum energies were found to add no advantage. This is because the costs (price of unit, installation, maintenance, shielding for neutron and photons) are not justified by either improved physical characteristics of the radiation (penetration, skin sparing, dose distribution) or treatment outcome. In fact, for photon beams some physical characteristics result in less desirable dose distributions, less accurate dosimetry, and increased safety problems as the energy increases for example, increasingly diffuse beam edges, loss of electron equilibrium, uncertainty in dose perturbations at interfaces, increased neutron contamination, and potential for higher personnel dose. The special features that make electron beams useful at lower energies, for example, skin sparing and small penetration, are lost at high energies. These physical factors are analyzed together with the economic factors related to radiation therapy patient care using megavoltage beams.

Radiation environment in the tunnel of a high-energy proton accelerator at energies near 1 TeV

International Nuclear Information System (INIS)

McCaslin, J.B.; Sun, R.K.S.; Swanson, W.P.

1987-12-01

Neutron energy spectra, fluence distributions and rates in the FNAL Tevatron tunnel are summarized. This work has application to radiation damage to electronics and research equipment at high energy accelerators, as well as to radiological protection. 7 refs., 4 figs

Endoscopic diode laser therapy for chronic radiation proctitis.

Science.gov (United States)

Polese, Lino; Marini, Lucia; Rizzato, Roberto; Picardi, Edgardo; Merigliano, Stefano

2018-01-01

The purpose of this study is to determine the effectiveness of endoscopic diode laser therapy in patients presenting rectal bleeding due to chronic radiation proctitis (CRP). A retrospective analysis of CRP patients who underwent diode laser therapy in a single institution between 2010 and 2016 was carried out. The patients were treated by non-contact fibers without sedation in an outpatient setting. Fourteen patients (median age 77, range 73-87 years) diagnosed with CRP who had undergone high-dose radiotherapy for prostatic cancer and who presented with rectal bleeding were included. Six required blood transfusions. Antiplatelet (three patients) and anticoagulant (two patients) therapy was not suspended during the treatments. The patients underwent a median of two sessions; overall, a mean of 1684 J of laser energy per session was used. Bleeding was resolved in 10/14 (71%) patients, and other two patients showed improvement (93%). Only one patient, who did not complete the treatment, required blood transfusions after laser therapy; no complications were noted during or after the procedures. Study findings demonstrated that endoscopic non-contact diode laser treatment is safe and effective in CRP patients, even in those receiving antiplatelet and/or anticoagulant therapy.

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 ...

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

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....

Radiative corrections to high-energy neutrino scattering

International Nuclear Information System (INIS)

Rujula, A. de; Petronzio, R.; Savoy-Navarro, A.

1979-01-01

Motivated by precise neutrino experiments, the electromagnetic radiative corrections to the data are reconsidered. The usefulness is investigated and the simplicity demonstrated of the 'leading log' approximation: the calculation to order α ln (Q/μ), α ln (Q/msub(q)). Here Q is an energy scale of the overall process, μ is the lepton mass and msub(q) is a hadronic mass, the effective quark mass in a parton model. The leading log radiative corrections to dsigma/dy distributions and to suitably interpreted dsigma/dx distributions are quark-mass independent. The authors improve upon the conventional leading log approximation and compute explicitly the largest terms that lie beyond the leading log level. In practice this means that the model-independent formulae, though approximate, are likely to be excellent estimates everywhere except at low energy or very large y. It is pointed out that radiative corrections to measurements of deviations from the Callan-Gross relation and to measurements of the 'sea' constituency of nucleons are gigantic. The QCD inspired study of deviations from scaling is of particular interest. The authors compute, beyond the leading log level, the radiative corrections of the QCD predictions. (Auth.)

Different Approaches in Radiation Therapy

Directory of Open Access Journals (Sweden)

Rolf-Dieter eKortmann

2011-12-01

Full Text Available Radiation therapy is a cornerstone in the therapeutic management of craniopharyngioma. The close proximity to neighbouring eloquent structures pose a particular challenge to radiation therapy. Modern treatment technologies including fractionated 3-d conformal radiotherapy, intensity modulated radiation therapy and recently proton therapy are able to precisely cover the target while preserving surrounding tissue,Tumour controls between 80 and in access of 90 % can be achieved. Alternative treatments consisting of radiosurgery, intracavitary application of isotopes and brachytherapy also offer an acceptable tumour control and might be given in selected cases. More research is needed to establish the role of each treatment modality.

High energy radiation effects on mechanical properties of butyl rubber compounds

International Nuclear Information System (INIS)

Pozenato, Cristina A.; Scagliusi, Sandra R.; Cardoso, Elisabeth C.L.; Lugao, Ademar B.

2013-01-01

The high energy radiation on butyl rubber compounds causes a number of chemical reactions that occur after initial ionization and excitation events. These reactions lead to changes in molecular mass of the polymer through scission and crosslinking of the molecules, being able to affect the physical and mechanical properties. Butyl rubber has excellent mechanical properties and oxidation resistance as well as low gas and water vapor permeability. Due to all these properties butyl rubber is widely used industrially and particularly in tires manufacturing. In accordance with various authors, the major effect of high energy, such as gamma rays in butyl rubber, is the yielding of free-radicals along with changes in mechanical properties. There were evaluated effects imparted from high energy radiation on mechanical properties of butyl rubber compounds, non-irradiated and irradiated with 25 kGy, 50 kGy, 150 kGy and 200 kGy. It was also observed a sharp reducing in stress rupture and elongation at break for doses higher than 50 kGy, pointing toward changes in polymeric chain along build-up of free radicals and consequent degradation. (author)

New three-dimensional moving field radiation therapy for brain tumors

Energy Technology Data Exchange (ETDEWEB)

Mitsuyama, Fuyuki; Kanno, Tetsuo; Nagata, Yutaka; Koga, Sukehiko [Fujita-Gakuen Health Univ., Toyoake, Aichi (Japan); Jain, V K

1992-06-01

A new modified rotation radiation method called 'three-dimensional moving field radiation therapy' is described. The new method uses rotation in many planes while maintaining the same isocenter to achieve a good spatial dose distribution. This delivers a high dose to tumors and spares the surrounding normal structures. This easy method can be carried out using the equipment for conventional rotation radiation therapy. The new method was superior to the one plane rotation radiation therapy using a physical phantom with film, a chemical phantom using the iodine-starch reaction, and a new biological model using tumor cells. Treatment of six brain tumors irradiated with total air doses of 50-60 Gy caused no hair loss or radiation necrosis. (author).

Radiation therapy for the treatment of feline advanced cutaneous squamous cell carcinoma

International Nuclear Information System (INIS)

Cunha, S.C.S.; Corgozinho, K.B.; Ferreira, A.M.R; Carvalho, L.A.V.; Holguin, P.G.

2014-01-01

The efficacy of radiation therapy for feline advanced cutaneous squamous cell carcinoma was evaluated. A full course radiation therapy protocol was applied to six cats showing single or multiple facial squamous cell carcinomas, in a total of seven histologically confirmed neoplastic lesions. Of the lesions, one was staged as T 1 , and six as T 4 according to WHO staging system of epidermal tumors. The animals were submitted to twelve radiation fractions of 4 Gy each, on a Monday-Wednesday-Friday schedule, and the equipment used was an orthovoltage unit. Energy used was 120 kV, 15 mA and 2 mm aluminum filter. The cats were evaluated during the treatment and 30 and 60 days after the end of the radiation therapy. In this study, 87% of the lesions had complete remission and 13% partial remission to the treatment. Side effects were considered mild according to Veterinary Radiation Therapy Oncology Group Toxicity criteria, and included erythema, epilation and rhinitis. Radiation Therapy was considered safe for feline cutaneous squamous cell carcinoma, leading to mild side effects and can represent a good therapeutic option. (author)

Radiation therapy alone for adenocarcinoma of the uterine cervix

International Nuclear Information System (INIS)

Nakano, Takashi; Arai, Tatsuo; Morita, Shinroku; Oka, Kuniyuki

1995-01-01

Purpose: Radiation therapy alone for adenocarcinoma of the cervix is currently evaluated by the accumulation of long-term results because of the low incidence of this disease. Materials and Methods: Fifty-eight patients with adenocarcinoma of the cervix treated with radiation therapy alone between 1961 and 1988 were studied. The radiation therapy consisted of a combination of intracavitary and external pelvis irradiation. Intracavitary treatment was performed with low dose rate and/or high dose rate sources. Results: The 5-year survival rates for Stages I, II, III, and IV were 85.7%, 66.7%, 32.3%, and 9.1%, respectively, and the 10-year survival rates were 85.7%, 60.0%, 27.6%, and 9.1%, respectively. The local control rate with high dose rate treatment was 45.5%, significantly lower than 85.7% and 72.7% with low and mixed dose rate treatments, respectively. Five-year survival and local control rates by tumor volume were 68.6% and 80.0% for small tumors, 63.6% and 66.0% for medium tumors, and 14.4% and 18.2% for large tumors, respectively. The survival rate and local control rate for large tumors were significantly lower than those for small and medium tumors. Multiple regression analysis indicated that stage and tumor volume were independent variables for survival and local control, respectively. Isoeffective dose expressed by time dose fractionation (TDF) was not associated with local control. Radiation complications developed in 10 patients (17.2%), most of which were of moderate degree. Conclusion: Radiation therapy alone for adenocarcinoma of the cervix was regarded to be an effective treatment, comparable to combination therapy of surgery and radiation therapy

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

Audit of high energy therapy beams in hospital oncology departments by the National Radiation Laboratory

International Nuclear Information System (INIS)

Smyth, V.G.

1994-02-01

In 1993 the output of every high energy radiotherapy beam used clinically in New Zealand was measured by National Radiation Laboratory (NRL) staff using independent dosimetry equipment. The purpose of this was to audit the dosimetry that is used by hospital physicists for the basis of patient treatments, and to uncover any errors that may be clinically significant. This report analyses the uncertainties involved in comparing the NRL and hospital measurements, and presents the results of the 1993 audit. The overall uncertainty turns out to be about 1.5%. The results for linear accelerator photon beams are consistent with a purely random variation within this uncertainty. Electron beams show some small errors beyond the expected uncertainty. Gamma beams have the potential to be the most accurately measured, but in practice are less accurately measured than linear accelerator beams. None of the disagreements indicated an error of clinical significance. 8 refs., 3 figs., 2 tabs

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...

High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

Energy Technology Data Exchange (ETDEWEB)

Bizen, Teruhiko [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)]. E-mail: bizen@spring8.or.jp; Asano, Yoshihiro [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Marechal, Xavier-Marie [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Seike, Takamitsu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Aoki, Tsuyoshi [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Fukami, Kenji [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hosoda, Naoyasu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Yonehara, Hiroto [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Takagi, Tetsuya [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hara, Toru [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Tanaka, Takashi [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kitamura, Hideo [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2007-05-11

High-energy electron-beam bombardment of Nd{sub 2}Fe{sub 14}B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small.

High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

International Nuclear Information System (INIS)

Bizen, Teruhiko; Asano, Yoshihiro; Marechal, Xavier-Marie; Seike, Takamitsu; Aoki, Tsuyoshi; Fukami, Kenji; Hosoda, Naoyasu; Yonehara, Hiroto; Takagi, Tetsuya; Hara, Toru; Tanaka, Takashi; Kitamura, Hideo

2007-01-01

High-energy electron-beam bombardment of Nd 2 Fe 14 B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small

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.)

Radiation hardness of silicon detectors - a challenge from high-energy physics

CERN Document Server

Lindström, G; Fretwurst, E

1999-01-01

An overview of the radiation-damage-induced problems connected with the application of silicon particle detectors in future high-energy physics experiments is given. Problems arising from the expected hadron fluences are summarized and the use of the nonionizing energy loss for normalization of bulk damage is explained. The present knowledge on the deterioration effects caused by irradiation is described leading to an appropriate modeling. Examples are given for a correlation between the change in the macroscopic performance parameters and effects to be seen on the microscopic level by defect analysis. Finally possible ways are out-lined for improving the radiation tolerance of silicon detectors either by operational conditions, process technology or defect engineering.

Radiation Therapy of Large Intact Breasts Using a Beam Spoiler or Photons with Mixed Energies

International Nuclear Information System (INIS)

Lief, Eugene P.; Hunt, Margie A.; Hong, Linda X.; Amols, Howard I.

2007-01-01

Radiation treatment of large intact breasts with separations of more than 24 cm is typically performed using x-rays with energies of 10 MV and higher, to eliminate high-dose regions in tissue. The disadvantage of the higher energy beams is the reduced dose to superficial tissue in the buildup region. We evaluated 2 methods of avoiding this underdosage: (1) a beam spoiler: 1.7-cm-thick Lucite plate positioned in the blocking tray 35 cm from the isocenter, with 15-MV x-rays; and (2) combining 6- and 15-MV x-rays through the same portal. For the beam with the spoiler, we measured the dose distribution for normal and oblique incidence using a film and ion chamber in polystyrene, as well as a scanning diode in a water tank. In the mixed-energy approach, we calculated the dose distributions in the buildup region for different proportions of 6- and 15-MV beams. The dose enhancement due to the beam spoiler exhibited significant dependence upon the source-to-skin distance (SSD), field size, and the angle of incidence. In the center of a 20 x 20-cm 2 field at 90-cm SSD, the beam spoiler raises the dose at 5-mm depth from 77% to 87% of the prescription, while maintaining the skin dose below 57%. Comparison of calculated dose with measurements suggested a practical way of treatment planning with the spoiler-usage of 2-mm 'beam' bolus-a special option offered by in-house treatment planning system. A second method of increasing buildup doses is to mix 6- and 15-MV beams. For example, in the case of a parallel-opposed irradiation of a 27-cm-thick phantom, dose to D max for each energy, with respect to midplane, is 114% for pure 6-, 107% for 15-MV beam with the spoiler, and 108% for a 3:1 mixture of 15- and 6-MV beams. Both methods are practical for radiation therapy of large intact breasts

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

Present status of quality assurance system for radiation therapy in the national hospital and sanatorium

International Nuclear Information System (INIS)

Uno, Takashi; Itami, Jun; Kotaka, Kikuo; Terui, Takashi

1994-01-01

In order to improve the precision of radiation therapy and structure of radiation oncology, the state of quality assurance (QA) system for external radiation therapy in Japanese national hospitals and sanatoriums were investigated, by a questionnaire method. The questionnaire included the equipments, the personnel, and a frequency in quality assurance check of each radiation therapy facilities. The results clarified that real photon energy of megavoltage equipment was measured in only 57% of 58% institutions; frequency of the dose monitor calibration was suboptimal; personnel scale was markedly insufficient; some treatment-related apparatus was inappropriately arranged between institutions. Based on these results, it was considered that the precision of radiation therapy and its QA state could not be improved without personnel sufficiency. In the present situation, we should consider the arrangement of treatment facilities in each area and specialization of radiation therapy between institutions. (author)

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

A self-powered thin-film radiation detector using intrinsic high-energy current

Energy Technology Data Exchange (ETDEWEB)

Zygmanski, Piotr, E-mail: pzygmanski@LROC.HARVARD.EDU, E-mail: Erno-Sajo@uml.edu [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Sajo, Erno, E-mail: pzygmanski@LROC.HARVARD.EDU, E-mail: Erno-Sajo@uml.edu [Department of Physics and Applied Physics, Medical Physics Program, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States)

2016-01-15

Purpose: The authors introduce a radiation detection method that relies on high-energy current (HEC) formed by secondary charged particles in the detector material, which induces conduction current in an external readout circuit. Direct energy conversion of the incident radiation powers the signal formation without the need for external bias voltage or amplification. The detector the authors consider is a thin-film multilayer device, composed of alternating disparate electrically conductive and insulating layers. The optimal design of HEC detectors consists of microscopic or nanoscopic structures. Methods: Theoretical and computational developments are presented to illustrate the salient properties of the HEC detector and to demonstrate its feasibility. In this work, the authors examine single-sandwiched and periodic layers of Cu and Al, and Au and Al, ranging in thickness from 100 nm to 300 μm and separated by similarly sized dielectric gaps, exposed to 120 kVp x-ray beam (half-value thickness of 4.1 mm of Al). The energy deposition characteristics and the high-energy current were determined using radiation transport computations. Results: The authors found that in a dual-layer configuration, the signal is in the measurable range. For a defined total detector thickness in a multilayer structure, the signal sharply increases with decreasing thickness of the high-Z conductive layers. This paper focuses on the computational results while a companion paper reports the experimental findings. Conclusions: Significant advantages of the device are that it does not require external power supply and amplification to create a measurable signal; it can be made in any size and geometry, including very thin (sub-millimeter to submicron) flexible curvilinear forms, and it is inexpensive. Potential applications include medical dosimetry (both in vivo and external), radiation protection, and other settings where one or more of the above qualities are desired.

A strategy to develop and implement Canadian standards for quality assurance in radiation therapy

International Nuclear Information System (INIS)

1999-05-01

In Canada, the Atomic Energy Control Board (AECB) regulates the limits of radiation exposure to the public and to workers in industry. In 1993, it discussed the fact that the safety of radiation therapy patients who receive medical exposures is not regulated [AE93]. The Group of Medical Advisors (GMA) to the AECB initiated a research contract to review quality assurance in Canadian radiation oncology centres and nuclear medicine departments. The review [MA95] revealed that the level of quality assurance in radiation therapy facilities varied across the country. As a result, the GMA undertook its own review of quality assurance in radiation therapy centres and made recommendations on how to achieve a uniform national system [MA98]. In response to the GMA report, the President of the AECB formed a Joint Working Group (JWG-11) to propose how Canadian Standards for Quality Assurance in Radiation Therapy could be developed and implemented. These national standards for quality assurance will serve as a common basis for establishing and evaluating quality assurance programs at individual radiation therapy centres. These standards should address the structure of quality assurance programs and quality assurance for radiation therapy equipment, personnel, and procedures. (author)

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

Protection of the patient in radiation therapy

International Nuclear Information System (INIS)

1991-01-01

In the ICRP report (ICRP-Pub-44) a broad picture of radiotheraphy is presented useful to all involved in the care of cancer patients, for instance to physicians, including medical oncologists, and to medical physicists, radiographers, dosimetrists, and administrators. Information is given on the general principles of radiation therapy including external beam therapy and brachytherapy; the accuracy of radiation delivery and quality assurance; the biological radiation response; the expected risk to specific organs or tissues from therapeutic irradiation; the absorbed dose to tissues inside and outside the useful radiation beams; the organization and planning of radiation oncology services; radiation therapy staff education, training and duties; and finally medical research involving the use of radiation therapy. (orig./HP) [de

Role of radiation therapy for 'juvenile' angiofibroma

Energy Technology Data Exchange (ETDEWEB)

Gudea, F.; Vega, M.; Canals, E.; Montserrat, J.M.; Valdano, J. (Univ. Autonoma de Barcelona (Spain). Hospital de la Santa Creu i Sant Pau (Spain))

1990-09-01

Juvenile nasopharyngeal angiofibroma (JNA) is a rare benign neoplasm which occurs primarily in male adolescents and is characterized by aggressive local growth. The controversy concerning appropriate treatment for patients with juvenile angiofibroma persists. Radiation therapy and survival resection have both been reported to be effective to control a high proportion of these tumours. The case reported here demonstrates a locally advanced JNA controlled by radiation therapy. (author).

Radiation biology and radiation therapy

International Nuclear Information System (INIS)

Wideroee, R.

1975-01-01

Radiation biology and radiation therapy can be compared with investigations in different layers of earth. Radiation biology works upwards from the elementary foundations, therapy works downwards with roots to secure and improve the clinical 'surface work'. The Ellis formula (Strandquist), which is a collection of clinical experience, is suited to form connections with radiobiology in the middle layers, and cooperation can give impulses for research. The structure and conditions of tumours and the complicated problems met with are discussed, based on the Carmel symposium of 1969. The oxygen problem in anoxic tumours is not yet solved. Experimental investigations of the effect itself give partly contradictory results. From a clinical viewpoint reoxygenation is of the utmost significance for obtaining control over the primary tumour, and advanced irradiation programmes will here give better results than the traditional ones. New chemicals, e.g. R 0 -07-0582, appear to reduce the OER value to 1.5, thereby making neutron therapy superfluous. Finally a problem from fundamental research is dealt with, wherein two hypotheses explaining the β-effect are described. The repair hypothesis gives a simple explanation but leaves many questions unanswered. The other hypothesis explains the β-effect as two neighbouring single breaks of the DNA molecule. It still presents difficulties, and is scarcely the correct explanation. (JIW)

A dual energy CT study on vascular effects of gold nanoparticles in radiation therapy

Science.gov (United States)

Ashton, Jeffrey R.; Hoye, Jocelyn; Deland, Katherine; Whitley, Melodi; Qi, Yi; Moding, Everett; Kirsch, David G.; West, Jennifer; Badea, Cristian T.

2016-03-01

Gold nanoparticles (AuNPs) are emerging as promising agents for both cancer therapy and CT imaging. AuNPs are delivered to tumors via the enhanced permeability and retention effect and they preferentially accumulate in close proximity to the tumor blood vessels. AuNPs produce low-energy, short-range photoelectrons during external beam radiation therapy (RT), boosting dose. This work is focused on understanding how tumor vascular permeability is influenced by AuNP-augmented radiation therapy (RT), and how this knowledge can potentially improve the delivery of additional nanoparticle-based chemotherapeutics. We use dual energy (DE) CT to detect accumulation of AuNPs and increased vascular permeability to liposomal iodine (i.e. a surrogate for chemotherapeutics with liposome encapsulation) following RT. We used sarcoma tumors generated in LSL-KrasG12D; p53FL/FL conditional mutant mice. A total of n=37 mice were used in this study. The treated mice were injected with 20 mg AuNP (0.1 ml/25 g mouse) 24 hours before delivery of 5 Gy RT (n=5), 10 Gy RT (n=3) or 20 Gy RT (n=6). The control mice received no AuNP injection and either no RT (n=6), 5 Gy RT (n=3), 10 Gy RT (n=3), 20 Gy RT (n=11). Twenty four hours post-RT, the mice were injected with liposomal iodine (0.3 ml/25 mouse) and imaged with DE-CT three days later. The results suggest that independent of any AuNP usage, RT levels of 10 Gy and 20 Gy increase the permeability of tumor vasculature to liposomal iodine and that the increase in permeability is dose-dependent. We found that the effect of RT on vasculature may already be at its maximum response i.e. saturated at 20 Gy, and therefore the addition of AuNPs had almost no added benefit. Similarly, at 5 Gy RT, our data suggests that there was no effect of AuNP augmentation on tumor vascular permeability. However, by using AuNPs with 10 Gy RT, we observed an increase in the vascular permeability, however this is not yet statistically significant due to the small

Preliminary Toxicity Analysis of 3-Dimensional Conformal Radiation Therapy Versus Intensity Modulated Radiation Therapy on the High-Dose Arm of the Radiation Therapy Oncology Group 0126 Prostate Cancer Trial

Energy Technology Data Exchange (ETDEWEB)

Michalski, Jeff M., E-mail: jmichalski@radonc.wustl.edu [Department of Radiation Oncology Washington University Medical Center, St. Louis, Missouri (United States); Yan, Yan [Radiation Therapy Oncology Group Statistical Center, Philadelphia, Pennsylvania (United States); Watkins-Bruner, Deborah [Emory University School of Nursing, Atlanta, Georgia (United States); Bosch, Walter R. [Department of Radiation Oncology Washington University Medical Center, St. Louis, Missouri (United States); Winter, Kathryn [Radiation Therapy Oncology Group Statistical Center, Philadelphia, Pennsylvania (United States); Galvin, James M. [Department of Radiation Oncology Thomas Jefferson University Hospital, Philadelphia, Pennsylvania (United States); Bahary, Jean-Paul [Department of Radiation Oncology Centre Hospitalier de l' Université de Montréal-Notre Dame, Montreal, QC (Canada); Morton, Gerard C. [Department of Radiation Oncology Toronto-Sunnybrook Regional Cancer Centre, Toronto, ON (Canada); Parliament, Matthew B. [Department of Oncology Cross Cancer Institute, Edmonton, AB (Canada); Sandler, Howard M. [Department of Radiation Oncology Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, California (United States)

2013-12-01

Purpose: To give a preliminary report of clinical and treatment factors associated with toxicity in men receiving high-dose radiation therapy (RT) on a phase 3 dose-escalation trial. Methods and Materials: The trial was initiated with 3-dimensional conformal RT (3D-CRT) and amended after 1 year to allow intensity modulated RT (IMRT). Patients treated with 3D-CRT received 55.8 Gy to a planning target volume that included the prostate and seminal vesicles, then 23.4 Gy to prostate only. The IMRT patients were treated to the prostate and proximal seminal vesicles to 79.2 Gy. Common Toxicity Criteria, version 2.0, and Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late morbidity scores were used for acute and late effects. Results: Of 763 patients randomized to the 79.2-Gy arm of Radiation Therapy Oncology Group 0126 protocol, 748 were eligible and evaluable: 491 and 257 were treated with 3D-CRT and IMRT, respectively. For both bladder and rectum, the volumes receiving 65, 70, and 75 Gy were significantly lower with IMRT (all P<.0001). For grade (G) 2+ acute gastrointestinal/genitourinary (GI/GU) toxicity, both univariate and multivariate analyses showed a statistically significant decrease in G2+ acute collective GI/GU toxicity for IMRT. There were no significant differences with 3D-CRT or IMRT for acute or late G2+ or 3+ GU toxicities. Univariate analysis showed a statistically significant decrease in late G2+ GI toxicity for IMRT (P=.039). On multivariate analysis, IMRT showed a 26% reduction in G2+ late GI toxicity (P=.099). Acute G2+ toxicity was associated with late G3+ toxicity (P=.005). With dose–volume histogram data in the multivariate analysis, RT modality was not significant, whereas white race (P=.001) and rectal V70 ≥15% were associated with G2+ rectal toxicity (P=.034). Conclusions: Intensity modulated RT is associated with a significant reduction in acute G2+ GI/GU toxicity. There is a trend for a

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

External Beam Radiation Therapy for Cancer

Science.gov (United States)

External beam radiation therapy is used to treat many types of cancer. it is a local treatment, where a machine aims radiation at your cancer. Learn more about different types of external beam radiation therapy, and what to expect if you're receiving treatment.

High-dose superselective intra-arterial cisplatin and concomitant radiation therapy for carcinoma of the oral cavity

International Nuclear Information System (INIS)

Suzuki, Gen; Tanaka, Norimitsu; Ogo, Etuyo

2007-01-01

The purpose of this study was to evaluate the effect of high-dose superselective intra-arterial cisplatin and concomitant radiation therapy for carcinoma of the oral cavities. The subjects consisted of 18 patients with carcinoma of the oral, and cavity treated with superselective intra-arterial infusion of high dose cisplatin (100 mg/body) concomitant with delivery of external beam radiotherapy (median total dose, 60.8 Gy) between 2001 and 2004. Sodium thiosulfate was administered intravenously to provide effective cisplatin neutlization. They were International Union Against Cancer (UICC)1997 stage II-IV (stage II: 4 patients, stage III: 4 patients, stage IV: 10 patients). Patients ranged from 43-81 years of age, with a median of 60 years, and included 14 men and 4 women. A follow-up period was 6 months minimum from the atart of the radiation therapy, the median follow up period at 28 months. The three-year overall survival rate was 71%. The three-year disease free rate and local control rate were 60% and 65%, respectively. Three-year local control rate of the T2-3 was achieved at 83%, and that for T4 at 50%. There was borderline significant difference in local control rate between T2-3 and T4 (p=0.05). We conclude that the high-dose superselective intra-arterial cisplatin and concomitant radiation therapy provides effective results in organ preservation for cancer of oral cavities. Further studies are also required to determine the validity of this method. (author)

Characterization of CERN-EU high energy reference radiation fields with recombination chamber

International Nuclear Information System (INIS)

Golnik, N.

1998-01-01

The CERN-EU reference radiation field facility (called CERFF) is available behind a shielding of high-energy particles beam at CERN since 1993. At present the parameters of the radiation from beam target are well investigated, however, there are still some serious doubts concerning contribution of low-LET concurrent radiation. This paper presents an experimental procedure for determination of the contribution from the concurrent radiation by measuring the absorbed dose and recombination index of radiation quality at different beam intensities. Additionally, the values of H * (10) were measured in several measuring locations. Measurements were performed with a REM-2 recombination chamber and compared with those obtained by using a HANDI-TEPC instrument. (author)

High energy synchrotron radiation. A new probe for condensed matter research

International Nuclear Information System (INIS)

Schneider, J.R.; Bouchard, R.; Brueckel, T.; Lippert, M.; Neumann, H.B.; Poulsen, H.F.; Ruett, U.; Schmidt, T.; Zimmermann, M. von

1994-01-01

The absorption of 150 keV synchrotron radiation in matter is weak and, as normally done with neutrons, bulk properties are studied in large samples. However, the k-space resolution obtained with a Triple Crystal Diffractometer (TCD) for high energy synchrotron radiation is about one order of magnitude better than in high resolution neutron diffraction. The technique has been applied to measure the structure factor S(Q) of amorphous solids up to momentum transfers of the order of 32 A -1 , to study the intermediate range Ortho-II ordering in large, high quality YBa 2 Cu 3 O 6.5 single crystals and for investigations of the defect scattering from annealed Czochralski grown silicon crystals. Magnetic superlattice reflections have been measured in MnF 2 demonstrating the potential of the technique for high resolution studies of ground state bulk antiferromagnetism. Recently the question of two length scales in the critical scattering at the 100 K phase transition in SrTiO 3 was studied. At the PETRA storage ring, which serves as an accumulator for the HERA electron-proton-ring at DESY and which can be operated up to electron energies of 12 GeV, an undulator beam line is currently under construction and should be available in summer 1995. It opens up exciting new research opportunities for photon energies from about 20 to 150 keV. (orig.)

Role of secondary low energy electrons in radiobiology and chemoradiation therapy of cancer

Science.gov (United States)

Sanche, Léon

2009-05-01

With the chemotherapeutic agent cisplatin bound to DNA, damage to the molecule by electrons of low and high energies increases by factors varying from 1.3 to 4.4. The enhancement in bond dissociation is triggered by modifications of the interaction of low energy electrons with DNA. From our understanding of the latter, the present Letter attempts to explain the basic radiation-damage mechanism responsible for the efficiency of the concomitant chemoradiation treatment of cancer. Such a basic comprehension of the direct effects of radiation may have implications in the design of new chemotherapeutic and radiosensitizing drugs, as well as in the development of more efficient protocols in chemoradiation therapy.

Radiation tolerant fiber optic humidity sensors for High Energy Physics applications

CERN Document Server

Berruti, Gaia Maria; Cusano, Andrea

This work is devoted to the development of fiber optic humidity sensors to be applied in high-energy physics applications and in particular in experiments currently running at CERN. The high radiation level resulting from the operation of the accelerator at full luminosity can cause serious performance deterioration of the silicon sensors which are responsible for the particle tracking. To increase their lifetime, the sensors must be kept cold at temperatures below 0 C. At such low temperatures, any condensation risk has to be prevented and a precise thermal and hygrometric control of the air filling and surrounding the tracker detector cold volumes is mandatory. The technologies proposed at CERN for relative humidity monitoring are mainly based on capacitive sensing elements which are not designed with radiation resistance characteristic. In this scenario, fiber optic sensors seem to be perfectly suitable. Indeed, the fiber itself, if properly selected, can tolerate a very high level of radiation, optical fi...

Pion radiation for high grade astrocytoma: results of a randomized study

International Nuclear Information System (INIS)

Pickles, Tom; Goodman, George B.; Rheaume, Dorianne E.; Duncan, Graeme G.; Fryer, Chris J.; Bhimji, Shamim; Ludgate, Charles; Syndikus, Isabel; Graham, Peter; Dimitrov, Mario; Bowen, Julie

1997-01-01

Purpose: This study attempted to compare within a randomized study the outcome of pion radiation therapy vs. conventional photon irradiation for the treatment of high-grade astrocytomas. Methods and Materials: Eighty-four patients were randomized to pion therapy (33-34.5 Gyπ), or conventional photon irradiation (60 Gy). Entry criteria included astrocytoma (modified Kernohan high Grade 3 or Grade 4), age 18-70, Karnofsky performance status (KPS) ≥50, ability to start irradiation within 30 days of surgery, unifocal tumor, and treatment volume < 850 cc. The high-dose volume in both arms was computed tomography enhancement plus a 2-cm margin. The study was designed with the power to detect a twofold difference between arms. Results: Eighty-one eligible patients were equally balanced for all known prognostic variables. Pion patients started radiation 7 days earlier on average than photon patients, but other treatment-related variables did not differ. There were no significant differences for either early or late radiation toxicity between treatment arms. Actuarial survival analysis shows no differences in terms of time to local recurrence or overall survival where median survival was 10 months in both arms (p = 0.22). The physician-assessed KPS and patient-assessed quality of life (QOL) measurements were generally maintained within 10 percentage points until shortly before tumor recurrence. There was no apparent difference in the serial KPS or QOL scores between treatment arms. Conclusion: In contrast to high linear energy transfer (LET) therapy for central nervous system tumors, such as neutron or neon therapy, the safety of pion therapy, which is of intermediate LET, has been reaffirmed. However, this study has demonstrated no therapeutic gain for pion therapy of glioblastoma

A novel transition radiation detector utilizing superconducting microspheres for measuring the energy of relativistic high-energy charged particles

International Nuclear Information System (INIS)

Yuan, Luke C.L.; Chen, C.P.; Huang, C.Y.; Lee, S.C.; Waysand, G.; Perrier, P.; Limagne, D.; Jeudy, V.; Girard, T.

2000-01-01

A novel transition radiation detector (TRD) utilizing superheated superconducting microspheres of tin of 22-26, 27-32 and 32-38 μm in diameter, respectively, has been constructed which is capable of measuring accurately the energy of relativistic high-energy charged particles. The test has been conducted in a high-energy electron beam facility at the CERN PS in the energy range of 1-10 GeV showing an energy dependence of the TR X-ray photon produced and hence the value γ=E/mc 2 of the charged particle

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.

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)

Monte Carlo and analytic simulations in nanoparticle-enhanced radiation therapy

Directory of Open Access Journals (Sweden)

Paro AD

2016-09-01

Full Text Available Autumn D Paro,1 Mainul Hossain,2 Thomas J Webster,1,3,4 Ming Su1,4 1Department of Chemical Engineering, Northeastern University, Boston, MA, USA; 2NanoScience Technology Center and School of Electrical Engineering and Computer Science, University of Central Florida, Orlando, Florida, USA; 3Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia; 4Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Science, Wenzhou Medical University, Zhejiang, People’s Republic of China Abstract: Analytical and Monte Carlo simulations have been used to predict dose enhancement factors in nanoparticle-enhanced X-ray radiation therapy. Both simulations predict an increase in dose enhancement in the presence of nanoparticles, but the two methods predict different levels of enhancement over the studied energy, nanoparticle materials, and concentration regime for several reasons. The Monte Carlo simulation calculates energy deposited by electrons and photons, while the analytical one only calculates energy deposited by source photons and photoelectrons; the Monte Carlo simulation accounts for electron–hole recombination, while the analytical one does not; and the Monte Carlo simulation randomly samples photon or electron path and accounts for particle interactions, while the analytical simulation assumes a linear trajectory. This study demonstrates that the Monte Carlo simulation will be a better choice to evaluate dose enhancement with nanoparticles in radiation therapy. Keywords: nanoparticle, dose enhancement, Monte Carlo simulation, analytical simulation, radiation therapy, tumor cell, X-ray 

Quality assurance in radiation therapy: clinical aspects

International Nuclear Information System (INIS)

Souhami, L.

1984-01-01

A survey was conducted in Latin America to evaluate the clinical aspects of quality assurance in radiotherapy. A questionnaire was prepared and sent to 46 institutions. Twenty-seven centers (58.5%), from nine countries, answered the questionnaire. The study was divided into three topics: a) patient-related statistics; b) staffing and education; and c) equipment and facilities. Radiotherapy training programs are available in only 37% of the centers studied. A large number of megavoltage units are old, operating at a shorter than optimum distance with sources of very low activity. The number of high energy linear accelerators is unsatisfactory. Problems in treatment planning facilities were also identified. Regionalization of radiation therapy services is recommended as a possible way to improve quality at a reasonable cost

Complex of programs for calculating radiation fields outside plane protecting shields, bombarded by high-energy nucleons

International Nuclear Information System (INIS)

Gel'fand, E.K.; Man'ko, B.V.; Serov, A.Ya.; Sychev, B.S.

1979-01-01

A complex of programs for modelling various radiation situations at high energy proton accelerators is considered. The programs are divided into there main groups according to their purposes. The first group includes programs for preparing constants describing the processes of different particle interaction with a substanc The second group of programs calculates the complete function of particle distribution arising in shields under irradiation by high energy nucleons. Concrete radiation situations arising at high energy proton accelerators are calculated by means of the programs of the third group. A list of programs as well as their short characteristic are given

Complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities

CERN Document Server

Bilski, P; D'Errico, F; Esposito, A; Fehrenbacher, G; Fernàndez, F; Fuchs, A; Golnik, N; Lacoste, V; Leuschner, A; Sandri, S; Silari, M; Spurny, F; Wiegel, B; Wright, P

2006-01-01

This report outlines the research needs and research activities within Europe to develop new and improved methods and techniques for the characterization of complex radiation fields at workplaces around high-energy accelerators and the next generation of thermonuclear fusion facilities under the auspices of the COordinated Network for RAdiation Dosimetry (CONRAD) project funded by the European Commission.

The PEREGRINE ^TM program: using physics and computer simulation to improve radiation therapy for cancer

Energy Technology Data Exchange (ETDEWEB)

Siantar, Christine L. Hartmann [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Moses, Edward I. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

1998-11-01

When using radiation to treat cancer, doctors rely on physics and computer technology to predict where radiation dose will by deposited in the patient. The accuracy of computerized treatment planning plays a critical role in the ultimate success or failure of the radiation treatment. Inaccurate dose calculations can result in either insufficient radiation for cure, or excessive radiation to nearby healthy tissue, which can reduce the patient's quality of life. This article describes how advanced physics, computer, and engineering techniques originally developed for nuclear weapons and high energy physics research are being used to predict radiation dose in cancer patients. Results for radiation therapy planning, achieved in the Lawrence Livermore National Laboratory (LLNL) PEREGRINE program, show that these tools can give doctors new insights into their patients' treatments by providing substantially more accurate dose distributions than have been available in the past. It is believed that greater accuracy in radiation therapy treatment planning will save lives by improving doctors' ability to target radiation to the tumor and reduce suffering by reducing the incidence of radiation-induced complications.

Doses to Carotid Arteries After Modern Radiation Therapy for Hodgkin Lymphoma

DEFF Research Database (Denmark)

Maraldo, M.V.; Brodin, Nils Patrik; Aznar, Marianne Camille

2013-01-01

Hodgkin lymphoma (HL) survivors are at an increased risk of stroke because of carotid artery irradiation. However, for early-stage HL involved node radiation therapy (INRT) reduces the volume of normal tissue exposed to high doses. Here, we evaluate 3-dimensional conformal radiation therapy (3D......-CRT), volumetric-modulated arc therapy (VMAT), and proton therapy (PT) delivered as INRT along with the extensive mantle field (MF) by comparing doses to the carotid arteries and corresponding risk estimates....

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)

Comparing two strategies of dynamic intensity modulated radiation therapy (dIMRT with 3-dimensional conformal radiation therapy (3DCRT in the hypofractionated treatment of high-risk prostate cancer

Directory of Open Access Journals (Sweden)

Yartsev Slav

2008-01-01

Full Text Available Abstract Background To compare two strategies of dynamic intensity modulated radiation therapy (dIMRT with 3-dimensional conformal radiation therapy (3DCRT in the setting of hypofractionated high-risk prostate cancer treatment. Methods 3DCRT and dIMRT/Helical Tomotherapy(HT planning with 10 CT datasets was undertaken to deliver 68 Gy in 25 fractions (prostate and simultaneously delivering 45 Gy in 25 fractions (pelvic lymph node targets in a single phase. The paradigms of pelvic vessel targeting (iliac vessels with margin are used to target pelvic nodes and conformal normal tissue avoidance (treated soft tissues of the pelvis while limiting dose to identified pelvic critical structures were assessed compared to 3DCRT controls. Both dIMRT/HT and 3DCRT solutions were compared to each other using repeated measures ANOVA and post-hoc paired t-tests. Results When compared to conformal pelvic vessel targeting, conformal normal tissue avoidance delivered more homogenous PTV delivery (2/2 t-test comparisons; p dose, 1–3 Gy over 5/10 dose points; p Conclusion dIMRT/HT nodal and pelvic targeting is superior to 3DCRT in dose delivery and critical structure sparing in the setting of hypofractionation for high-risk prostate cancer. The pelvic targeting paradigm is a potential solution to deliver highly conformal pelvic radiation treatment in the setting of nodal location uncertainty in prostate cancer and other pelvic malignancies.

Clinical experience of radiation therapy for Graves` ophthalmopathy

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Takahashi, Takeo; Mitsuhashi, Norio; Nagashima, Hisako; Sakurai, Hideyuki; Murata, Osamu; Ishizeki, Kei; Shimaya, Sanae; Hayakawa, Kazushige; Niibe, Hideo [Gunma Univ., Maebashi (Japan). School of Medicine

1996-11-01

The effect of radiation therapy for Graves` ophthalmopathy was evaluated. Ten patients with Graves` ophthalmopathy were treated with radiation therapy between 1992 and 1993 in Gunma University Hospital. All patients had a past history of hyperthyroidism and received 2,000 cGy to the retrobulbar tissues in 20 fractions. Nine of ten patients were treated with radiation therapy after the failure of corticosteroids. Six patients (60%) showed good or excellent responses. The exophthalmos type was more responsive to radiation therapy than the double vision type in this series. Two of five patients with the exophthalmos type demonstrated excellent responses, and their symptoms disappeared almost completely. The improvement of symptoms appeared within 3-6 months, and obvious clinical effects were demonstrated after 6 months of radiotherapy. Radiation therapy was well tolerated, and we have not observed any side effects of radiation therapy. In conclusion, radiation therapy is effective treatment for Graves` ophthalmopathy. (author)

Clinical experience of radiation therapy for Graves' ophthalmopathy

International Nuclear Information System (INIS)

Takahashi, Takeo; Mitsuhashi, Norio; Nagashima, Hisako; Sakurai, Hideyuki; Murata, Osamu; Ishizeki, Kei; Shimaya, Sanae; Hayakawa, Kazushige; Niibe, Hideo

1996-01-01

The effect of radiation therapy for Graves' ophthalmopathy was evaluated. Ten patients with Graves' ophthalmopathy were treated with radiation therapy between 1992 and 1993 in Gunma University Hospital. All patients had a past history of hyperthyroidism and received 2,000 cGy to the retrobulbar tissues in 20 fractions. Nine of ten patients were treated with radiation therapy after the failure of corticosteroids. Six patients (60%) showed good or excellent responses. The exophthalmos type was more responsive to radiation therapy than the double vision type in this series. Two of five patients with the exophthalmos type demonstrated excellent responses, and their symptoms disappeared almost completely. The improvement of symptoms appeared within 3-6 months, and obvious clinical effects were demonstrated after 6 months of radiotherapy. Radiation therapy was well tolerated, and we have not observed any side effects of radiation therapy. In conclusion, radiation therapy is effective treatment for Graves' ophthalmopathy. (author)

A low power high speed radiation hard serializer for High Energy Physics experiments

CERN Document Server

AUTHOR|(CDS)2080243; Marchioro, Alessandro; Ottavi, Marco

This Ph.D. thesis focuses on the development and the characterization of novel solutions for electronic systems for high-speed data transmission in extremely high radio-active environment (e.g. high energy physics application). The text proposes two alternative full-custom solutions for a fundamental enabling block for a lowpower serial data transmission system, the serializer. This block will find place in a future transceiver conceived for the future upgraded phase of the Large Hadron Collider, or LHC, at CERN. The first solution proposed, called “triple module redundancy”, is based on hardware redundancy, a well-known solution, to obtain protection against the temporary malfunctioning induced by radiation. In the second case a new architecture, called “code protected”, is proposed. This architecture takes advantage of the error correction code present in the data word to obtain radiation robustness on data and some parts of the control logic and to further reduce the power consumption. A test chip ...

An investigation of build-up effects in high energy radiation fields using a Handi TEPC

International Nuclear Information System (INIS)

Aroua, A.; Sannikov, A.V.

1995-01-01

ICRP considers that a dose limit of 2 mSv close to the body surface of a pregnant woman will ensure a dose limit of 1 mSv to the foetus. This assumption depends on the energy spectrum and composition of the radiation fields, especially those containing high energy particles such as are found around particle accelerators or in aircraft. In this work the response of a tissue-equivalent proportional counter in radiation fields of different composition and energy was measured as a function of depth in cylindrical phantoms. The decrease in dose and dose equivalent at a phantom depth equivalent to that of a foetus was 10% in a typical high energy stray radiation field and 30% for neutrons from a Pu-Be source. It is concluded that it would be prudent in these cases to limit the exposure of a pregnant woman to 1 mSv in order to ensure that the dose to the foetus stays below the same limit. (Author)

Palliative radiation therapy for overloading radiotherapy centre, especially for developing country

International Nuclear Information System (INIS)

Myo, M.; Susworo; San, T.

2001-01-01

In a developing country, most of the cancer cases are diagnosed in the advanced stages. So, the palliative radiation therapy is the only choice of therapy for these inoperable cases where chemotherapy is not effective or affordable. In conventional radiation therapy, a daily dose of 200 cGy for total 4000 cGy in more than 20 fractions (sometimes, up to 6000 cGy) is used. By using linear-quadratic model theory of cell killing by radiation, it can be calculated early and late effects by using alpha and beta ratio. This theory is still the best for radiation cell killing until the new detail one is discovered. These data are obtained by experimental as well as clinical results. The effective radiation dose can be calculated by using the data to different organs which is involved in the radiation fields. This can change the daily dose to palliative cases in which the late effect is unnecessary. The daily doses can be 300, 400, 500, and sometimes 1000 cGy per single fraction. These modalities are well documented. It is recommend to change the short term high-dose palliative radiation therapy instead of using conventional palliative radiation therapy in overloading radiotherapy centre, especially for developing country. The reasons are mainly radiation protection aspect, not only for the patients and those who involved with the radiation therapy but also to reduce the unnecessary radiation exposure to the environment. (author)

Trial Watch: Immunotherapy plus radiation therapy for oncological indications.

Science.gov (United States)

Vacchelli, Erika; Bloy, Norma; Aranda, Fernando; Buqué, Aitziber; Cremer, Isabelle; Demaria, Sandra; Eggermont, Alexander; Formenti, Silvia Chiara; Fridman, Wolf Hervé; Fucikova, Jitka; Galon, Jérôme; Spisek, Radek; Tartour, Eric; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

2016-01-01

Malignant cells succumbing to some forms of radiation therapy are particularly immunogenic and hence can initiate a therapeutically relevant adaptive immune response. This reflects the intrinsic antigenicity of malignant cells (which often synthesize a high number of potentially reactive neo-antigens) coupled with the ability of radiation therapy to boost the adjuvanticity of cell death as it stimulates the release of endogenous adjuvants from dying cells. Thus, radiation therapy has been intensively investigated for its capacity to improve the therapeutic profile of several anticancer immunotherapies, including (but not limited to) checkpoint blockers, anticancer vaccines, oncolytic viruses, Toll-like receptor (TLR) agonists, cytokines, and several small molecules with immunostimulatory effects. Here, we summarize recent preclinical and clinical advances in this field of investigation.

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

Surface dose measurements under stretched, perforated thermoplast sheets and under protective wound dressings for high energy photon radiation

International Nuclear Information System (INIS)

Staudenraus, J.; Christ, G.

2000-01-01

Patient fixation masks made of perforated thermoplast sheets are widely used in radiotherapy. These masks in particular serve to immobilize the head and neck region during radiation treatment. We placed samples made of differently stretched, perforated mask material on the surface of a white polystyrene (RW3) phantom and measured for high energy photon beams from Co-60 radiation up to 25 MV bremsstrahlung the dose increase resulting from the build-up under the hole and bridge areas. Depending on the energy of the incident beam and the thickness of the stretched mask material we observed a dose increase under the bridges at the phantom surface of 55% up to 140% compared to the dose without a layer of mask material. Under a hole the dose increase is almost half the value found under a bridge. However, deeper than 1 mm under the phantom surface this difference in dose increase under holes and bridges decreases to less than 10%. The mean dose increase under a perforated thermoplast sheet is lower than the dose increase under a homogeneous sheet made of the same material with the same mean thickness. Radiation induced skin lesions or an ulcerating tumour, respectively, may require a protective wound dressing under a patient fixation mask during radiation therapy. Choosing a thin hydrocolloid wound dressing the additional dose increase of the skin, compared to the dose increase due to the fixation mask, can be kept low. (orig.) [de

Characteristics of background radiation behind one-dimensional radiation shielding of high-energy particle beams; Kharakteristiki fonovogo izlucheniya za odnomernymi radiatsionnymi zashchitami puchkov vysokoehnergeticheskikh chastits

Energy Technology Data Exchange (ETDEWEB)

Gorbatkov, D V; Kryuchkov, V P

1994-12-31

The calculational investigations of component, spatial and energy distributions of background radiation behind radiation shielding of high-energy hadron beams were carried out. The relations between different ingredients of radiation have been obtained. The numerous data of spatial and energy distribution of protons, neutrons, pions and photons in homogeneous and heterogeneous shielding from concrete and iron, presented in the paper, can be used as a reference data. 23 refs., 50 figs.

Radical radiation therapy for prostate cancer in Japan. A patterns of care study report

International Nuclear Information System (INIS)

Nakamura, Katsumasa; Mitsuhashi, Norio

2003-01-01

The patterns of radical radiation therapy for prostate cancer are unclear in Japan. A Patterns of Care Study was performed throughout Japan to examine the patterns of radiation therapy for prostate cancer. From 1999 to 2000, extramural audits were performed on 50 randomly selected institutions (∼7% of all institutions in Japan). Detailed information was collected on a total of 311 prostate cancer patients without evidence of distant metastases, who were treated by radiation therapy between 1996 and 1998. Of these 311 patients, 162 treated radically using photon beams were analyzed in this study. Eighty percent of the patients had high-risk diseases defined as T3 or T4 tumors, a pretreatment prostate-specific antigen level >20 ng/ml or poorly differentiated adenocarcinoma. Androgen ablation was performed in 85.8% of patients and the median duration of hormonal therapy before and after radiation therapy was 5.3 and 21.4 months, respectively. The median total dose of radiation therapy to the prostate was 65.0 Gy (range: 20-74 Gy). The 3-year overall and biochemical relapse-free survival rates were 86.7 and 86.1%, respectively. Late toxicity was mild, with only nine patients (5.6%) exhibiting grade 2 late morbidity. The majority of the patients who received radical radiation therapy in Japan have high-risk disease. Androgen ablation plus radiation therapy was commonly used to treat these patients and resulted in high rates of initial control with a low risk of complications. (author)

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.)

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

High-energy versus low-energy extracorporeal shock wave therapy for calcifying tendinitis of the shoulder: which is superior? A meta-analysis.

Science.gov (United States)

Verstraelen, F U; In den Kleef, N J H M; Jansen, L; Morrenhof, J W

2014-09-01

There are several treatment options for calcifying tendinitis of the shoulder. The next step treatment after conservative treatment fails is still a matter of dispute. Extracorporeal shock wave therapy (ESWT) has been shown to be a good alternative to surgery, but the best treatment intensity remains unknown. High-energy ESWT is much more painful, more expensive, and usually is done in an inpatient setting, whereas low-energy ESWT can be performed in an outpatient setting by a physical therapist. A systematic review and meta-analysis of randomized trials was performed to answer two clear research questions: (1) Is there a greater increase in the Constant-Murley score in patients treated with high-energy ESWT compared with those treated with low-energy ESWT by 3 months and by 6 months? (2) Is there a greater chance of complete resorption of the calcifications in patients treated with high-energy ESWT compared with those treated with low-energy ESWT by 3 months and by 6 months? Five relevant electronic online databases, Medline (through PubMed), EMBASE (through OVID), Cinahl (through EBSCO), Web of Science, and the Cochrane Central Register of Controlled Trials, were systematically searched. We also crosschecked the reference lists of articles and reviews for possible relevant studies. Eligible for inclusion were all randomized controlled trials (RCTs) that compared high-energy ESWT (> 0.28 mJ/mm(2)) with low-energy ESWT (energy ESWT compared with patients treated with low-energy ESWT at 3 and 6 months. The 3-month mean difference was 9.88 (95% CI, 9.04-10.72, p energy ESWT more often resulted in complete resorption of the deposits at 3 months. The corresponding odds ratio was 3.40 (95% CI, 1.35-8.58) and p = 0.009 (6-month data could not be pooled). When shock wave therapy is chosen, high-energy shock wave therapy is more likely to result in improved Constant-Murley score and resorption of the deposits compared with low-energy therapy. Level I, therapeutic study

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...

Technical basis of radiation therapy. Practical clinical applications. 5. ed.

Energy Technology Data Exchange (ETDEWEB)

Levitt, Seymour H. [Karolinska Institutet Stockholm (Sweden). Dept. of Oncol-Pathol; Perez, Carlos A. [Washington Univ. Medical Center, St. Louis, MO (United States). Dept. of Radiation Oncology; Purdy, James A. [California Univ., Sacramento, CA (United States). Dept. of Radiation Oncology; Poortmans, Philip [Institute Verbeeten, Tilburg (Netherlands). Dept. of Radiation Oncology

2012-07-01

This well-received book, now in its fifth edition, is unique in providing a detailed description of the technological basis of radiation therapy. Another novel feature is the collaborative writing of the chapters by North American and European authors. This considerably broadens the book's perspective and increases its applicability in daily practice throughout the world. The book is divided into two sections. The first covers basic concepts in treatment planning, including essential physics and biological principles related to time-dose-fractionation, and explains the various technological approaches to radiation therapy, such as intensity-modulated radiation therapy, tomotherapy, stereotactic radiotherapy, and high and low dose rate brachytherapy. Issues relating to quality assurance, technology assessment, and cost-benefit analysis are also reviewed. The second part of the book discusses in depth the practical clinical applications of the different radiation therapy techniques in a wide range of cancer sites. All of the chapters have been written by leaders in the field. This book will serve to instruct and acquaint teachers, students, and practitioners in the various fields of oncology with the basic technological factors and approaches in radiation therapy. (orig.)

Radiation effects on semiconductor devices in high energy heavy ion accelerators

Energy Technology Data Exchange (ETDEWEB)

Belousov, Anton

2014-10-20

Radiation effects on semiconductor devices in GSI Helmholtz Center for Heavy Ion Research are becoming more and more significant with the increase of beam intensity due to upgrades. Moreover a new accelerator is being constructed on the basis of GSI within the project of facility for antiproton and ion research (FAIR). Beam intensities will be increased by factor of 100 and energies by factor of 10. Radiation fields in the vicinity of beam lines will increase more than 2 orders of magnitude and so will the effects on semiconductor devices. It is necessary to carry out a study of radiation effects on semiconductor devices considering specific properties of radiation typical for high energy heavy ion accelerators. Radiation effects on electronics in accelerator environment may be divided into two categories: short-term temporary effects and long-term permanent degradation. Both may become critical for proper operation of some electronic devices. This study is focused on radiation damage to CCD cameras in radiation environment of heavy ion accelerator. Series of experiments with irradiation of devices under test (DUTs) by secondary particles produced during ion beam losses were done for this study. Monte Carlo calculations were performed to simulate the experiment conditions and conditions expected in future accelerator. Corresponding comparisons and conclusions were done. Another device typical for accelerator facilities - industrial Ethernet switch was tested in similar conditions during this study. Series of direct irradiations of CCD and MOS transistors with heavy ion beams were done as well. Typical energies of the primary ion beams were 0.5-1 GeV/u. Ion species: from Na to U. Intensities of the beam up to 10{sup 9} ions/spill with spill length of 200-300 ns. Criteria of reliability and lifetime of DUTs in specific radiation conditions were formulated, basing on experimental results of the study. Predictions of electronic device reliability and lifetime were

Variable-Energy Cyclotron for Proton Therapy Application

CERN Document Server

Alenitsky, Yu G; Vorozhtsov, A S; Glazov, A A; Mytsyn, G V; Molokanov, A G; Onishchenko, L M

2004-01-01

The requirements to characteristics of the beams used for proton therapy are considered. The operation and proposed cyclotrons for proton therapy are briefly described. The technical decisions of creation of the cyclotron with energy variation in the range 70-230 MeV and with current up to 100 nA are estimated. Taking into account the fact, that the size and cost of the cyclotron are approximately determined by the maximum proton energy, it is realistically offered to limit the maximum proton energy to 190 MeV and to elaborate a cyclotron project with a warm winding of the magnet for acceleration of H^{-} ions. The energy of the extracted protons for each run is determined by a stripped target radius in the vacuum chamber of the accelerator, and the radiation dose field for the patient is created by the external devices using the developed techniques.

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.

Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study

International Nuclear Information System (INIS)

Lee, Katrina; Lenards, Nishele; Holson, Janice

2016-01-01

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.

Final Report. Hydrodynamics by high-energy-density plasma flow and hydrodynamics and radiative hydrodynamics with astrophysical application

International Nuclear Information System (INIS)

R Paul Drake

2004-01-01

OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves

External radiation therapy of prostatic carcinoma and its relationship to hormonal therapy

International Nuclear Information System (INIS)

Takada, Chitose; Ito, Koushiro; Nishi, Junko; Yamamoto, Toshihiro; Hatanaka, Yoshimi; Baba, Yuji; Takahashi, Mutsumasa.

1995-01-01

From 1980 to 1990, a total of 54 patients with prostatic carcinoma were treated with external radiation therapy at the Kumamoto National Hospital. Ten patients were classified as Stage B, 22 as Stage C, and another 22 as Stage D according to the American Urological Association Clinical Staging System. The 5-year survival for all 54 patients was 30%. The 5-year disease-specific survival was 67% for Stage B, 47% for Stage C, and 26% for Stage D. The 5-year survival was 43% for patients in whom radiation therapy was initiated immediately after the first diagnosis or with less than one year of hormonal therapy, while it was 0% for patients in whom radiation therapy was initiated after more than one year of hormonal therapy (p=0.01). The cause of intercurrent death was acute myocardial infarction in four patients and acute cardiac failure in one. Four of these patients received hormonal therapy for more than one year. The incidence of radiation-induced proctitis was not severe. This study suggests that long-term hormonal therapy prior to radiation therapy worsens the prognosis of patients with prostatic carcinoma. (author)

Accelerated hypofractionated radiation therapy compared to conventionally fractionated radiation therapy for the treatment of inoperable non-small cell lung cancer

Directory of Open Access Journals (Sweden)

Amini Arya

2012-03-01

Full Text Available Abstract Background While conventionally fractionated radiation therapy alone is an acceptable option for poor prognostic patients with unresectable stage III NSCLC, we hypothesized that accelerated hypofractionated radiotherapy will have similar efficacy without increasing toxicity. Methods This is a retrospective analysis of 300 patients diagnosed with stage III NSCLC treated between 1993 and 2009. Patients included in the study were medically or surgically inoperable, were free of metastatic disease at initial workup and did not receive concurrent chemotherapy. Patients were categorized into three groups. Group 1 received 45 Gy in 15 fractions over 3 weeks (Accelerated Radiotherapy (ACRT while group 2 received 60-63 Gy (Standard Radiation Therapy 1 (STRT1 and group 3 received > 63 Gy (Standard Radiation Therapy (STRT2. Results There were 119 (39.7% patients in the ACRT group, 90 (30.0% in STRT1 and 91 (30.3% in STRT2. More patients in the ACRT group had KPS ≤ 60 (p 5% (p = 0.002, and had stage 3B disease (p Conclusions Despite the limitations of a retrospective analysis, our experience of accelerated hypofractionated radiation therapy with 45 Gy in 15 fractions appears to be an acceptable treatment option for poor performance status patients with stage III inoperable tumors. Such a treatment regimen (or higher doses in 15 fractions should be prospectively evaluated using modern radiation technologies with the addition of sequential high dose chemotherapy in stage III NSCLC.

New challenges in high-energy particle radiobiology

Science.gov (United States)

2014-01-01

Densely ionizing radiation has always been a main topic in radiobiology. In fact, α-particles and neutrons are sources of radiation exposure for the general population and workers in nuclear power plants. More recently, high-energy protons and heavy ions attracted a large interest for two applications: hadrontherapy in oncology and space radiation protection in manned space missions. For many years, studies concentrated on measurements of the relative biological effectiveness (RBE) of the energetic particles for different end points, especially cell killing (for radiotherapy) and carcinogenesis (for late effects). Although more recently, it has been shown that densely ionizing radiation elicits signalling pathways quite distinct from those involved in the cell and tissue response to photons. The response of the microenvironment to charged particles is therefore under scrutiny, and both the damage in the target and non-target tissues are relevant. The role of individual susceptibility in therapy and risk is obviously a major topic in radiation research in general, and for ion radiobiology as well. Particle radiobiology is therefore now entering into a new phase, where beyond RBE, the tissue response is considered. These results may open new applications for both cancer therapy and protection in deep space. PMID:24198199

Collaboration with a local organization on the subjects of energy/radiation field in high school science education

International Nuclear Information System (INIS)

Suzuki, Takahiro; Mori, Chizuo

2005-01-01

We, high school teachers, collaborated with a local organization, Chubu Atomic Power Conference (partly in co-operation with The Radiation Education Forum), in the education on the subjects of energy and radiation fields. In addition to the subjects concerned with radiations, cloud chamber and personal radiation-monitor, we developed a few new subjects, which are not directly connected themselves with radiations, for the purpose to widen the fields and to bring the high acceptability of the subjects in high school side. (author)

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

International Nuclear Information System (INIS)

Okumura, Toshiyuki; Itai, Yuji; Tsuji, Hiroshi

1994-01-01

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

Actual survey of dose evaluation method for standardization of radiation therapy techniques. With special reference to display method of radiation doses

International Nuclear Information System (INIS)

Kumagai, Kozo; Yoshiura, Takao; Izumi, Takashi; Araki, Fujio; Takada, Takuo; Jingu, Kenichi.

1994-01-01

This report presents the results of questionnaire survey for actual conditions of radiation therapy, which was conducted with the aim of establishing the standardization of radiation therapy techniques. Questionnaires were sent to 100 facilities in Japan, and 86 of these answered, consisting of 62 university hospitals, 2 national hospitals, 14 cancer centers, 4 prefectural or municipal hospitals, and 4 other hospitals. In addition to electron beam therapy, the following typical diseases for radiation therapy were selected as standard irradiation models: cancers of the larynx, esophagus, breast, and uterine cervix, and malignant lymphomas. According to these models, questionnaire results are analyzed in terms of the following four items: (1) irradiation procedures, (2) energy used for radiotherapy, (3) the depth for calculating target absorption doses, and (4) points for displaying target absorption doses. (N.K.)

New apparatus with high radiation energy between 320 to 460 nm: physical description and dermatological applications

International Nuclear Information System (INIS)

Mutzhas, M.F.; Holzle, E.; Hofmann, C.; Plewig, G.

1981-01-01

A new apparatus (UVASUN 5000) is presented with high radiation energy between 320 to 460 nm. The radiator is a specially developed source for high uv-A intensity, housing a quartz bulb with a mixture of argon, mercury and metal-halides. The uv-A energy in the range of 320 to 400 nm is about 84% of the total radiation energy. Effects of very high doses of uv-A on human skin were studied. Following single uv-A applications the minimal tanning dose uv-A (MTD) and the immediate pigment darkening (IPD) dose of uv-A were established. Repeated exposure to this uv-A delivering system yields long lasting dark brown skin pigmentation without any clinical or histological signs of sunburn (uv-B) damage, epidermal hyperplasia or thickening of the stratum corneum. Minimal therapeutic results were seen in the phototherapy of vitiligo and inflammatory acne

Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

Science.gov (United States)

Higuchi, Yoshinori; Nelson, Gregory A.; Vazquez, Marcelo; Laskowitz, Daniel T.; Slater, James M.; Pearlstein, Robert D.

2002-01-01

Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. METHODS: Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. ROTAROD TEST: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. OPEN FIELD TEST: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. MORRIS WATER MAZE: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. CONCLUSIONS: These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the CNS. ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process.

Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

International Nuclear Information System (INIS)

Higuchi, Yoshinori; Nelson, G.A.; Slater, J.M.; Pearlstein, R.D.; Laskowitz, D.T.

2002-01-01

Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. Rotarod test: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. Open field test: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. Morris water maze: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the central nervous system (CNS). ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process. (author)

Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

Energy Technology Data Exchange (ETDEWEB)

Higuchi, Yoshinori; Nelson, G.A.; Slater, J.M.; Pearlstein, R.D. [Loma Linda Univ., CA (United States). Medical Center; Vazquez, M. [Brookhaven National Lab., Upton, NY (United States); Laskowitz, D.T. [Duke Univ., Durham, NC (United States). Medical Center

2002-12-01

Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. Rotarod test: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. Open field test: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. Morris water maze: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the central nervous system (CNS). ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process. (author)

Radiation protection and dosimetry problems around medium energy accelerators

Energy Technology Data Exchange (ETDEWEB)

Pavlovic, R; Pavlovic, S; Markovic, S [Inst. of Nuclear Sciences Vinca, Belgrade (Yugoslavia); Boreli, F [Fac. of Electrical Engineering, Belgrade (Yugoslavia)

1996-12-31

In the Institute of Nuclear Sciences `VINCA`, the Accelerator Installation `TESLA`, which is an ion accelerator facility consisting of an isochronous cyclotron `VINCY`, a heavy ion source, a D{sup -} / H{sup -} ion source, three low energy and five high energy experimental channels is now under construction. The Tesla Accelerator Installation should by the principal facility for basic and applied research in physics, chemistry, biology, and material science, as well as for production of radioisotopes, medical diagnostics and therapy with radioisotopes and accelerated particle beams. Some problems in defining radiation protection and safety programme, particularly problems in construction appropriate shielding barriers at the Accelerator Installation `TESLA` are discussed in this paper. (author) 1 fig., 9 refs.

Compilation of radiation damage test data part III: materials used around high-energy accelerators

CERN Document Server

Beynel, P; Schönbacher, H; CERN. Geneva

1982-01-01

For pt.II see CERN report 79-08 (1979). This handbook gives the results of radiation damage tests on various engineering materials and components intended for installation in radiation areas of the CERN high-energy particle accelerators. It complements two previous volumes covering organic cable-insulating materials and thermoplastic and thermosetting resins.

Imaging and Data Acquisition in Clinical Trials for Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

FitzGerald, Thomas J., E-mail: Thomas.Fitzgerald@umassmed.edu [Imaging and Radiation Oncology Core Rhode Island, University of Massachusetts Memorial Medical Center, University of Massachusetts Medical School, Worcester, Massachusetts (United States); Bishop-Jodoin, Maryann [Imaging and Radiation Oncology Core Rhode Island, University of Massachusetts Medical School, Worcester, Massachusetts (United States); Followill, David S. [Imaging and Radiation Oncology Core Houston, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Galvin, James [Imaging and Radiation Oncology Core Philadelphia, Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Knopp, Michael V. [Imaging and Radiation Oncology Core Ohio, Wexner Medical Center, Ohio State University, Columbus, Ohio (United States); Michalski, Jeff M. [Imaging and Radiation Oncology Core St. Louis, Washington University School of Medicine, St. Louis, Missouri (United States); Rosen, Mark A. [Imaging and Radiation Oncology Core Philadelphia, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States); Bradley, Jeffrey D. [Washington University School of Medicine–Radiation Oncology, St. Louis, Missouri (United States); Shankar, Lalitha K. [National Cancer Institute, Clinical Radiation Oncology Branch, Rockville, Maryland (United States); Laurie, Fran [Imaging and Radiation Oncology Core Rhode Island, University of Massachusetts Medical School, Worcester, Massachusetts (United States); Cicchetti, M. Giulia; Moni, Janaki [Imaging and Radiation Oncology Core Rhode Island, University of Massachusetts Memorial Medical Center, University of Massachusetts Medical School, Worcester, Massachusetts (United States); Coleman, C. Norman; Deye, James A.; Capala, Jacek; Vikram, Bhadrasain [National Cancer Institute, Clinical Radiation Oncology Branch, Rockville, Maryland (United States)

2016-02-01

Cancer treatment evolves through oncology clinical trials. Cancer trials are multimodal and complex. Assuring high-quality data are available to answer not only study objectives but also questions not anticipated at study initiation is the role of quality assurance. The National Cancer Institute reorganized its cancer clinical trials program in 2014. The National Clinical Trials Network (NCTN) was formed and within it was established a Diagnostic Imaging and Radiation Therapy Quality Assurance Organization. This organization is Imaging and Radiation Oncology Core, the Imaging and Radiation Oncology Core Group, consisting of 6 quality assurance centers that provide imaging and radiation therapy quality assurance for the NCTN. Sophisticated imaging is used for cancer diagnosis, treatment, and management as well as for image-driven technologies to plan and execute radiation treatment. Integration of imaging and radiation oncology data acquisition, review, management, and archive strategies are essential for trial compliance and future research. Lessons learned from previous trials are and provide evidence to support diagnostic imaging and radiation therapy data acquisition in NCTN trials.

Imaging and Data Acquisition in Clinical Trials for Radiation Therapy

International Nuclear Information System (INIS)

FitzGerald, Thomas J.; Bishop-Jodoin, Maryann; Followill, David S.; Galvin, James; Knopp, Michael V.; Michalski, Jeff M.; Rosen, Mark A.; Bradley, Jeffrey D.; Shankar, Lalitha K.; Laurie, Fran; Cicchetti, M. Giulia; Moni, Janaki; Coleman, C. Norman; Deye, James A.; Capala, Jacek; Vikram, Bhadrasain

2016-01-01

Cancer treatment evolves through oncology clinical trials. Cancer trials are multimodal and complex. Assuring high-quality data are available to answer not only study objectives but also questions not anticipated at study initiation is the role of quality assurance. The National Cancer Institute reorganized its cancer clinical trials program in 2014. The National Clinical Trials Network (NCTN) was formed and within it was established a Diagnostic Imaging and Radiation Therapy Quality Assurance Organization. This organization is Imaging and Radiation Oncology Core, the Imaging and Radiation Oncology Core Group, consisting of 6 quality assurance centers that provide imaging and radiation therapy quality assurance for the NCTN. Sophisticated imaging is used for cancer diagnosis, treatment, and management as well as for image-driven technologies to plan and execute radiation treatment. Integration of imaging and radiation oncology data acquisition, review, management, and archive strategies are essential for trial compliance and future research. Lessons learned from previous trials are and provide evidence to support diagnostic imaging and radiation therapy data acquisition in NCTN trials.

Shielding technology for high energy radiation production facility

International Nuclear Information System (INIS)

Lee, Byung Chul; Kim, Heon Il

2004-06-01

In order to develop shielding technology for high energy radiation production facility, references and data for high energy neutron shielding are searched and collected, and calculations to obtain the characteristics of neutron shield materials are performed. For the evaluation of characteristics of neutron shield material, it is chosen not only general shield materials such as concrete, polyethylene, etc., but also KAERI developed neutron shields of High Density PolyEthylene (HDPE) mixed with boron compound (B 2 O 3 , H 2 BO 3 , Borax). Neutron attenuation coefficients for these materials are obtained for later use in shielding design. The effect of source shape and source angular distribution on the shielding characteristics for several shield materials is examined. This effect can contribute to create shielding concept in case of no detail source information. It is also evaluated the effect of the arrangement of shield materials using current shield materials. With these results, conceptual shielding design for PET cyclotron is performed. The shielding composite using HDPE and concrete is selected to meet the target dose rate outside the composite, and the dose evaluation is performed by configuring the facility room conceptually. From the result, the proper shield configuration for this PET cyclotron is proposed

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.

A Novel Simple Phantom for Verifying the Dose of Radiation Therapy

Directory of Open Access Journals (Sweden)

J. H. Lee

2015-01-01

Full Text Available A standard protocol of dosimetric measurements is used by the organizations responsible for verifying that the doses delivered in radiation-therapy institutions are within authorized limits. This study evaluated a self-designed simple auditing phantom for use in verifying the dose of radiation therapy; the phantom design, dose audit system, and clinical tests are described. Thermoluminescent dosimeters (TLDs were used as postal dosimeters, and mailable phantoms were produced for use in postal audits. Correction factors are important for converting TLD readout values from phantoms into the absorbed dose in water. The phantom scatter correction factor was used to quantify the difference in the scattered dose between a solid water phantom and homemade phantoms; its value ranged from 1.084 to 1.031. The energy-dependence correction factor was used to compare the TLD readout of the unit dose irradiated by audit beam energies with 60Co in the solid water phantom; its value was 0.99 to 1.01. The setup-condition factor was used to correct for differences in dose-output calibration conditions. Clinical tests of the device calibrating the dose output revealed that the dose deviation was within 3%. Therefore, our homemade phantoms and dosimetric system can be applied for accurately verifying the doses applied in radiation-therapy institutions.

Use dibunol therapy for radiation injuries of the skin and mucous membranes

Energy Technology Data Exchange (ETDEWEB)

Agafonova, G.B.; Barsel' , V.A.; Sarkisyan, Yu.Kh.; Terekhova, G.S.; Podlyashchuk, E.L.; Ustinova, V.F. (Nauchno-Issledovatel' skij Inst. Rentgenologii i Radiologii, Moscow (USSR); AN SSSR, Moscow. Inst. Khimicheskoj Fiziki)

1983-04-01

There are presented the results of the use of dibunol in the form of liniment (1-10%) for the treatment of radiation cystitis and rectitis resulting from radiation therapy of small pelvic tumors, epidermitis and epithelitis that develop in the course of treatment of skin and lower lip tumors. A high efficacy of the drug in the therapy of radiation injury has been shown in 212 patients.

High dose radiation damage in nuclear energy structural materials investigated by heavy ion irradiation simulation

International Nuclear Information System (INIS)

Zheng Yongnan; Xu Yongjun; Yuan Daqing

2014-01-01

Structural materials in ITER, ADS and fast reactor suffer high dose irradiations of neutrons and/or protons, that leads to severe displacement damage up to lOO dpa per year. Investigation of radiation damage induced by such a high dose irradiation has attracted great attention along with the development of nuclear energy facilities of new generation. However, it is deeply hampered for the lacking of high dose neutron and proton sources. Irradiation simulation of heavy ions produced by accelerators opens up an effective way for laboratory investigation of high dose irradiation induced radiation damage encountered in the ITER, ADS, etc. Radiation damage is caused mainly by atomic displacement in materials. The displacement rate of heavy ions is about lO 3 ∼10 7 orders higher than those of neutrons and protons. High displacement rate of heavy ions significantly reduces the irradiation time. The heavy ion irradiation simulation technique (HIIS) technique has been developed at China Institute of Atomic Energy and a series of the HIIS experiments have been performed to investigate radiation damage in stainless steels, tungsten and tantalum at irradiation temperatures from room temperature to 800 ℃ and in the irradiation dose region up to 100 dpa. The experimental results show that he radiation swelling peak for the modified stainless steel appears in the temperature region around 580 ℃ and the radiation damage is more sensitive to the temperature, the size of the radiation induced vacancy cluster or void increase with the increasing of the irradiation dose, and among the three materials the home-made modified stainless steel has the best radiation resistant property. (authors)

Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study.

Science.gov (United States)

Lee, Katrina; Lenards, Nishele; Holson, Janice

2016-01-01

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. Copyright © 2016 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Sacral chordomas: Impact of high-dose proton/photon-beam radiation therapy combined with or without surgery for primary versus recurrent tumor

International Nuclear Information System (INIS)

Park, Lily; De Laney, Thomas F.; Liebsch, Norbert J.; Hornicek, Francis J.; Goldberg, Saveli; Mankin, Henry; Rosenberg, Andrew E.; Rosenthal, Daniel I.; Suit, Herman D.

2006-01-01

Purpose: To assess the efficacy of definitive treatment of sacral chordoma by high-dose proton/photon-beam radiation therapy alone or combined with surgery. Methods and Materials: The records of 16 primary and 11 recurrent sacral chordoma patients treated from November 1982 to November 2002 by proton/photon radiation therapy alone (6 patients) or combined with surgery (21 patients) have been analyzed for local control, survival, and treatment-related morbidity. The outcome analysis is based on follow-up information as of 2005. Results: Outcome results show a large difference in local failure rate between patients treated for primary and recurrent chordomas. Local control results by surgery and radiation were 12/14 vs. 1/7 for primary and recurrent lesions. For margin-positive patients, local control results were 10 of 11 and 0 of 5 in the primary and recurrent groups, respectively; the mean follow-up on these locally controlled patients was 8.8 years (4 at 10.3, 12.8, 17, and 21 years). Radiation alone was used in 6 patients, 4 of whom received ≥73.0 Gy (E); local control was observed in 3 of these 4 patients for 2.9, 4.9, and 7.6 years. Conclusion: These data indicate a high local control rate for surgical and radiation treatment of primary (12 of 14) as distinct from recurrent (1 of 7) sacral chordomas. Three of 4 chordomas treated by ≥73.0 Gy (E) of radiation alone had local control; 1 is at 91 months. This indicates that high-dose proton/photon therapy offers an effective treatment option

Scatter Dose in Patients in Radiation Therapy

International Nuclear Information System (INIS)

Schmidt, W. F. O.

2003-01-01

Patients undergoing radiation therapy are often treated with high energy radiation (bremsstrahlung) which causes scatter doses in the patients from various sources as photon scatter coming from collimator, gantry, patient, patient table or room (walls, floor, air) or particle doses resulting from gamma-particle reactions in the atomic nucleus if the photon energies are above 8 MeV. In the last years new treatment techniques like IMRT (esp the step-and-shoot- or the MIMIC-techniques) have increased interest in these topics again. In the lecture an overview about recent measurements on scatter doses resulting from gantry, table and room shall be given. Scatter doses resulting from the volume treated in the patient to other critical parts of the body like eyes, ovarii etc. have been measured in two diploma works in our institute and are compared with a program (PERIDOSE; van der Giessen, Netherlands) to estimate them. In some cases these scatter doses have led to changes of treatment modalities. Also an overview and estimation of doses resulting from photon-particle interactions is given according to a publication from Gudowska et al.(Gudowska I, Brahme A, Andreo P, Gudowski W, Kierkegaard J. Calculation of absorbed dose and biological effectiveness from photonuclear reactions in a bremsstrahlung beam of end point 50 MeV. Phys Med Biol 1999; 44(9):2099-2125.). Energy dose has been calculated with Monte Carlo-methods and is compared with analytical methods for 50 MV bremsstrahlung. From these data biologically effective doses from particles in different depths of the body can be estimated also for energies used in normal radiotherapy. (author)

Indirect radio-chemo-beta therapy: a targeted approach to increase biological efficiency of x-rays based on energy.

Science.gov (United States)

Oktaria, Sianne; Corde, Stéphanie; Lerch, Michael L F; Konstantinov, Konstantin; Rosenfeld, Anatoly B; Tehei, Moeava

2015-10-21

Despite the use of multimodal treatments incorporating surgery, chemotherapy and radiotherapy, local control of gliomas remains a major challenge. The potential of a new treatment approach called indirect radio-chemo-beta therapy using the synergy created by combining methotrexate (MTX) with bromodeoxyuridine (BrUdR) under optimum energy x-ray irradiation is assessed. 9L rat gliosarcoma cells pre-treated with 0.01 μM MTX and/or 10 μM BrUdR were irradiated in vitro with 50 kVp, 125 kVp, 250 kVp, 6 MV and 10 MV x-rays. The cytotoxicity was assessed using clonogenic survival as the radiobiological endpoint. The photon energy with maximum effect was determined using radiation sensitization enhancement factors at 10% clonogenic survival (SER10%). The cell cycle distribution was investigated using flow cytometric analysis with propidium iodide staining. Incorporation of BrUdR in the DNA was detected by the fluorescence of labelled anti-BrUdR antibodies. The radiation sensitization enhancement exhibits energy dependence with a maximum of 2.3 at 125 kVp for the combined drug treated cells. At this energy, the shape of the clonogenic survival curve of the pharmacological agents treated cells changes substantially. This change is interpreted as an increased lethality of the local radiation environment and is attributed to supplemented inhibition of DNA repair. Radiation induced chemo-beta therapy was demonstrated in vitro by the targeted activation of combined pharmacological agents with optimized energy tuning of x-ray beams on 9 L cells. Our results show that this is a highly effective form of chemo-radiation therapy.

Combined neck dissection and postoperative radiation therapy in the management of the high-risk neck: a matched-pair analysis

International Nuclear Information System (INIS)

Lundahl, Robert E.; Foote, Robert L.; Bonner, James A.; Suman, Vera J.; Lewis, Jean E.; Kasperbauer, Jan L.; McCaffrey, Thomas V.; Olsen, Kerry D.

1998-01-01

Purpose: The purpose of this study was to determine the efficacy of postoperative adjuvant radiation therapy with regard to reducing the rate of recurrence in the neck, cancer-related death, and death from any cause in patients with squamous cell carcinoma of the head and neck region metastatic to neck nodes. Methods: This was a retrospective review of patients with pathologically confirmed nodal metastases who underwent neck dissection and postoperative adjuvant radiation therapy for squamous cell carcinoma of the head and neck region. Time to recurrence in the dissected area of the neck, any recurrence in the neck, cancer-related death, and death from any cause were estimated with the Kaplan-Meier method. A matched-pair analysis was performed utilizing a cohort of patients who underwent neck dissection without postoperative radiation therapy. The patients from the two cohorts were matched according to previously reported high-risk features for cancer recurrence and death. Cox hazards models for the matched pairs were used to evaluate the relative risk of subsequent recurrence in the dissected side of the neck, any neck recurrence, cancer-related death, and overall survival. Materials: The medical records and pathologic slides of 95 consecutive patients with pathologically confirmed nodal metastases from squamous cell carcinoma of the head and neck region who underwent neck dissection and postoperative adjuvant radiation therapy between January 1974 and December 1990 were reviewed. Previously published data from 284 patients with squamous cell carcinoma of the head and neck region treated with neck dissection alone between January 1970 and December 1980 were used for a matched-pair analysis. Results: The relative risks for recurrence in the dissected side of the neck, any neck recurrence (dissected neck or delayed undissected neck metastasis), cancer-related death, and death from any cause for patients treated with operation alone relative to those treated with

Tracheoinnominate artery fistula as a complication of radiation therapy

International Nuclear Information System (INIS)

Reiter, D.; Piccone, B.R.; Littman, P.; Lisker, S.A.

1979-01-01

Tracheoinnominate artery fistulization is a well-known complication of tracheostomy and of tracheal resection. The first known occurrence of this problem in a patient in whom no transtracheal procedure had ever been performed is reported, and high-dose radiation therapy delivered three years before for a mediastinal malignancy is suggested as the cause. No evidence of tumor was found in or adjacent to the tracheovascular communication. The tracheoinnominate artery fistula must be considered a potential complication of radiation therapy as well as of surgery

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

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

Ionizing radiation, radiation sources, radiation exposure, radiation effects. Pt. 2

International Nuclear Information System (INIS)

Schultz, E.

1985-01-01

Part 2 deals with radiation exposure due to artificial radiation sources. The article describes X-ray diagnosis complete with an analysis of major methods, nuclear-medical diagnosis, percutaneous radiation therapy, isotope therapy, radiation from industrial generation of nucler energy and other sources of ionizing radiation. In conclusion, the authors attempt to asses total dose, genetically significant dose and various hazards of total radiation exposure by means of a summation of all radiation impacts. (orig./WU) [de

Cherenkov Video Imaging Allows for the First Visualization of Radiation Therapy in Real Time

International Nuclear Information System (INIS)

Jarvis, Lesley A.; Zhang, Rongxiao; Gladstone, David J.; Jiang, Shudong; Hitchcock, Whitney; Friedman, Oscar D.; Glaser, Adam K.; Jermyn, Michael; Pogue, Brian W.

2014-01-01

Purpose: To determine whether Cherenkov light imaging can visualize radiation therapy in real time during breast radiation therapy. Methods and Materials: An intensified charge-coupled device (CCD) camera was synchronized to the 3.25-μs radiation pulses of the clinical linear accelerator with the intensifier set × 100. Cherenkov images were acquired continuously (2.8 frames/s) during fractionated whole breast irradiation with each frame an accumulation of 100 radiation pulses (approximately 5 monitor units). Results: The first patient images ever created are used to illustrate that Cherenkov emission can be visualized as a video during conditions typical for breast radiation therapy, even with complex treatment plans, mixed energies, and modulated treatment fields. Images were generated correlating to the superficial dose received by the patient and potentially the location of the resulting skin reactions. Major blood vessels are visible in the image, providing the potential to use these as biological landmarks for improved geometric accuracy. The potential for this system to detect radiation therapy misadministrations, which can result from hardware malfunction or patient positioning setup errors during individual fractions, is shown. Conclusions: Cherenkoscopy is a unique method for visualizing surface dose resulting in real-time quality control. We propose that this system could detect radiation therapy errors in everyday clinical practice at a time when these errors can be corrected to result in improved safety and quality of radiation therapy

Megavoltage radiation therapy: Meeting the technological needs

International Nuclear Information System (INIS)

Van Dyk, J.

2002-01-01

addressing technological needs for megavoltage radiation treatment, that the radiation treatment machine technology not be considered in isolation from the technologies associated with the other steps of the treatment process. It makes no sense to have highly sophisticated linear accelerators capable of 3-D conformal and intensity modulated radiation therapy (IMRT) if there is not a good imaging capability for accurately defining the extent and location of both tumours and normal tissues. Requirements for a radiation therapy facility have been defined in an IAEA report. This report considered cobalt-60 megavoltage therapy machines but indicated that the IAEA would not consider provisions for linear accelerators. In 1993, the Pan American Health Organization along with the WHO and the IAEA produced a report describing the design requirements for megavoltage x-ray machines for cancer treatment in developing countries. Clearly, even within the last decade, there are still different opinions on the benefits (and risks) of cobalt-60 versus linear accelerators for provision of radiation treatment especially in the context of developing countries. There are a number of considerations when a particular institution in any country makes decisions about the purchase of radiation therapy equipment. Broadly speaking, these include: Societal infrastructure considerations (e.g. is there stable electrical power available to support the treatment and related technologies?); Financial considerations (e.g. are there sufficient financial resources to purchase, operate, maintain and eventually dispose of the treatment technology?); Types and stage of diseases most likely to be treated (e.g. late stage diseases have different planning and treatment requirements compared to early stage and well localized tumours); The number and types of professional staff available to support the treatment technologies (e.g. radiation oncologists, medical physicists, radiation therapists (technologists), and

External and internal radiation therapy: Past and future directions

Directory of Open Access Journals (Sweden)

Sadeghi Mahdi

2010-01-01

Full Text Available Cancer is a leading cause of morbidity and mortality in the modern world. Treatment modalities comprise radiation therapy, surgery, chemotherapy and hormonal therapy. Radiation therapy can be performed by using external or internal radiation therapy. However, each method has its unique properties which undertakes special role in cancer treatment, this question is brought up that: For cancer treatment, whether external radiation therapy is more efficient or internal radiation therapy one? To answer this question, we need to consider principles and structure of individual methods. In this review, principles and application of each method are considered and finally these two methods are compared with each other.

Dose distribution following selective internal radiation therapy

International Nuclear Information System (INIS)

Fox, R.A.; Klemp, P.F.; Egan, G.; Mina, L.L.; Burton, M.A.; Gray, B.N.

1991-01-01

Selective Internal Radiation Therapy is the intrahepatic arterial injection of microspheres labelled with 90Y. The microspheres lodge in the precapillary circulation of tumor resulting in internal radiation therapy. The activity of the 90Y injected is managed by successive administrations of labelled microspheres and after each injection probing the liver with a calibrated beta probe to assess the dose to the superficial layers of normal tissue. Predicted doses of 75 Gy have been delivered without subsequent evidence of radiation damage to normal cells. This contrasts with the complications resulting from doses in excess of 30 Gy delivered from external beam radiotherapy. Detailed analysis of microsphere distribution in a cubic centimeter of normal liver and the calculation of dose to a 3-dimensional fine grid has shown that the radiation distribution created by the finite size and distribution of the microspheres results in an highly heterogeneous dose pattern. It has been shown that a third of normal liver will receive less than 33.7% of the dose predicted by assuming an homogeneous distribution of 90Y

Utilization of a photon transport code to investigate radiation therapy treatment planning quantities and techniques

International Nuclear Information System (INIS)

Palta, J.R.

1981-01-01

A versatile computer program MORSE, based on neutron and photon transport theory has been utilzed to investigate radiation therapy treatment planning quantities and techniques. A multi-energy group representation of transport equation provides a concise approach in utilizing Monte Carlo numerical techniques to multiple radiation therapy treatment planning problems. Central axis total and scattered dose distributions for homogeneous and inhomogeneous water phantoms are calculated and the correction factor for lung and bone inhomogeneities are also evaluated. Results show that Monte Carlo calculations based on multi-energy group tansport theory predict the depth dose distributions that are in good agreement with available experimental data. Central axis depth dose distributions for a bremsstrahlung spectrum from a linear accelerator is also calculated to exhibit the versatility of the computer program in handling multiple radiation therapy problems. A novel approach is undertaken to study the dosimetric properties of brachytherapy sources

High resolution X-ray fluorescence imaging for a microbeam radiation therapy treatment planning system

Science.gov (United States)

Chtcheprov, Pavel; Inscoe, Christina; Burk, Laurel; Ger, Rachel; Yuan, Hong; Lu, Jianping; Chang, Sha; Zhou, Otto

2014-03-01

Microbeam radiation therapy (MRT) uses an array of high-dose, narrow (~100 μm) beams separated by a fraction of a millimeter to treat various radio-resistant, deep-seated tumors. MRT has been shown to spare normal tissue up to 1000 Gy of entrance dose while still being highly tumoricidal. Current methods of tumor localization for our MRT treatments require MRI and X-ray imaging with subject motion and image registration that contribute to the measurement error. The purpose of this study is to develop a novel form of imaging to quickly and accurately assist in high resolution target positioning for MRT treatments using X-ray fluorescence (XRF). The key to this method is using the microbeam to both treat and image. High Z contrast media is injected into the phantom or blood pool of the subject prior to imaging. Using a collimated spectrum analyzer, the region of interest is scanned through the MRT beam and the fluorescence signal is recorded for each slice. The signal can be processed to show vascular differences in the tissue and isolate tumor regions. Using the radiation therapy source as the imaging source, repositioning and registration errors are eliminated. A phantom study showed that a spatial resolution of a fraction of microbeam width can be achieved by precision translation of the mouse stage. Preliminary results from an animal study showed accurate iodine profusion, confirmed by CT. The proposed image guidance method, using XRF to locate and ablate tumors, can be used as a fast and accurate MRT treatment planning system.

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

International Nuclear Information System (INIS)

Bolderston, Amanda

2008-01-01

Objectives: The purpose of this study was to discover and compare radiation therapy patients' and radiation therapists' perceptions of patients' educational topics of interest and methods of information delivery during a course of radiation therapy. Methods: Using Likert-type 4-point rating scales, 42 therapists and 183 radiation therapy patients were surveyed to rate the degree of importance of 15 informational items (for example, 'What it feels like to have treatment'). In addition, therapists and patients ranked 11 methods of informational delivery (for example, 'Watching video tapes') in order of preference. Results: Results indicated several differences in therapists' and patients' perceptions of both the educational topics of interest and methods of information delivery. Among other things, patients assigned high importance to after treatment issues ('What happens after radiation therapy is finished') and how radiation therapy works, these areas were not seen as important by the studied therapists. Patients expressed a strong preference for receiving information about radiation therapy from their family doctor (ranked third), therapists ranked this source of information as the least important. Conclusion: It is vital to tailor educational interventions according to the patient's preference to optimize both understanding and compliance. This study demonstrated noteworthy differences in several areas between therapists' and patients' perceptions. Recommendations therefore include raising therapist's awareness of topics that are important to patients and meaningful informational delivery methods

Radiation hygienization of cattle and swine slurry with high energy electron beam

International Nuclear Information System (INIS)

Skowron, Krzysztof; Olszewska, Halina; Paluszak, Zbigniew; Zimek, Zbigniew; Kałuska, Iwona; Skowron, Karolina Jadwiga

2013-01-01

The research was carried out to assess the efficiency of radiation hygienization of cattle and swine slurry of different density using the high energy electron beam based on the inactivation rate of Salmonella ssp, Escherichia coli, Enterococcus spp and Ascaris suum eggs. The experiment was conducted with use of the linear electron accelerator Elektronika 10/10 in Institute of Nuclear Chemistry and Technology in Warsaw. The inoculated slurry samples underwent hygienization with high energy electron beam of 1, 3, 5, 7 and 10 kGy. Numbers of reisolated bacteria were determined according to the MPN method, using typical microbiological media. Theoretical lethal doses, D 90 doses and hygienization efficiency of high energy electron beam were determined. The theoretical lethal doses for all tested bacteria ranged from 3.63 to 8.84 kGy and for A. suum eggs from 4.07 to 5.83 kGy. Salmonella rods turned out to be the most sensitive and Enterococcus spp were the most resistant to electron beam hygienization. The effectiveness or radiation hygienization was lower in cattle than in swine slurry and in thick than in thin one. Also the species or even the serotype of bacteria determined the dose needed to inactivation of microorganisms. - Highlights: ► The hygienic efficiency of electron beam against slurry was researched. ► The hygienization efficiency depended on the slurry characteristics and microorganism species. ► In most of the cases 7 kGy dose was sufficient for slurry hygienization. ► Dose below 1 kGy allowed for 90% elimination of microorganism population. ► The radiation hygienization is a good alternative for typical slurry treatment methods

In vivo dosimetry in radiation therapy in Sweden

International Nuclear Information System (INIS)

Eriksson, Jacob; Blomquist, Michael

2010-07-01

A prerequisite for achieving high radiation safety for patients receiving external beam radiation therapy is that the hospitals have a quality assurance program. The program should include include monitoring of the radiation dose given to the patient. Control measurements are performed both at the system level and at the individual level. Control measurement is normally performed using in vivo dosimetry, e.g. a method to measure the radiation dose at the individual level during the actual radiation treatment time. In vivo dosimetry has proven to be an important tool to detect and prevent serious errors in patient treatment. The purpose of this research project was to identify the extent to which vivo dosimetry is used and the methods available for this at Swedish radiation therapy clinics. The authority also wanted to get an overall picture of how hospitals manage results of in vivo dosimetry, and how clinics control radiation dose when using modern treatment techniques. The report reflects the situation in Swedish radiotherapy clinics 2007. The report shows that all hospitals use some form of in vivo dosimetry. The instruments used are mainly diodes and termoluminiscence dosimeters

Modern radiation therapy for extranodal lymphomas

DEFF Research Database (Denmark)

Yahalom, Joachim; Illidge, Tim; Specht, Lena

2015-01-01

Extranodal lymphomas (ENLs) comprise about a third of all non-Hodgkin lymphomas (NHL). Radiation therapy (RT) is frequently used as either primary therapy (particularly for indolent ENL), consolidation after systemic therapy, salvage treatment, or palliation. The wide range of presentations of ENL...... and treatment planning for the most frequently involved organs. Specifically, detailed recommendations for RT volumes are provided. We have applied the same modern principles of involved site radiation therapy as previously developed and published as guidelines for Hodgkin lymphoma and nodal NHL. We have...... there is a lack of guidelines for the use of RT in the management of ENL. This report presents an effort by the International Lymphoma Radiation Oncology Group (ILROG) to harmonize and standardize the principles of treatment of ENL, and to address the technical challenges of simulation, volume definition...

Factors influencing radiation therapy student clinical placement satisfaction

Science.gov (United States)

Bridge, Pete; Carmichael, Mary-Ann

2014-01-01

Introduction: Radiation therapy students at Queensland University of Technology (QUT) attend clinical placements at five different clinical departments with varying resources and support strategies. This study aimed to determine the relative availability and perceived importance of different factors affecting student support while on clinical placement. The purpose of the research was to inform development of future support mechanisms to enhance radiation therapy students’ experience on clinical placement. Methods: This study used anonymous Likert-style surveys to gather data from years 1 and 2 radiation therapy students from QUT and clinical educators from Queensland relating to availability and importance of support mechanisms during clinical placements in a semester. Results: The study findings demonstrated student satisfaction with clinical support and suggested that level of support on placement influenced student employment choices. Staff support was perceived as more important than physical resources; particularly access to a named mentor, a clinical educator and weekly formative feedback. Both students and educators highlighted the impact of time pressures. Conclusions: The support offered to radiation therapy students by clinical staff is more highly valued than physical resources or models of placement support. Protected time and acknowledgement of the importance of clinical education roles are both invaluable. Joint investment in mentor support by both universities and clinical departments is crucial for facilitation of effective clinical learning. PMID:26229635

Factors influencing radiation therapy student clinical placement satisfaction

Energy Technology Data Exchange (ETDEWEB)

Bridge, Pete; Carmichael, Mary-Ann [School of Clinical Sciences, Queensland University of Technology, Brisbane (Australia)

2014-02-15

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

Factors influencing radiation therapy student clinical placement satisfaction

International Nuclear Information System (INIS)

Bridge, Pete; Carmichael, Mary-Ann

2014-01-01

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

Radiation Therapy for Cancer

Science.gov (United States)

... can cause pain. Radiation given to shrink a tumor near the esophagus , which can interfere with a patient’s ability to eat and drink. How is radiation therapy planned for an individual ... show the location of a patient’s tumor and the normal areas around it. These scans ...

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

International Nuclear Information System (INIS)

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

2012-01-01

Purpose: To determine the incidence of and risk factors for radiation pneumonitis (RP) after stereotactic ablative radiation therapy (SABR) to the lung in patients who had previously undergone conventional thoracic radiation therapy. Methods and Materials: Seventy-two patients who had previously received conventionally fractionated radiation therapy to the thorax were treated with SABR (50 Gy in 4 fractions) for recurrent disease or secondary parenchymal lung cancer (T 10 and mean lung dose (MLD) of the previous plan and the V 10 -V 40 and MLD of the composite plan were also related to RP. Multivariate analysis revealed that ECOG PS scores of 2-3 before SABR (P=.009), FEV1 ≤65% before SABR (P=.012), V 20 ≥30% of the composite plan (P=.021), and an initial PTV in the bilateral mediastinum (P=.025) were all associated with RP. Conclusions: We found that severe RP was relatively common, occurring in 20.8% of patients, and could be predicted by an ECOG PS score of 2-3, an FEV1 ≤65%, a previous PTV spanning the bilateral mediastinum, and V 20 ≥30% on composite (previous RT+SABR) plans. Prospective studies are needed to validate these predictors and the scoring system on which they are based.

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

High technology for radiation application

International Nuclear Information System (INIS)

Iida, Toshiyuki

2005-03-01

Fundamentals of radiations, radioactivity, and their applications in recent industrial, medical, agricultural and various research fields are reviewed. The book begins with historical description regarding to discovery of radiation at the end of 19th century and the exploration into the inside of an atom utilizing the radiation discovered, discovery of the neutron which finally leaded to nuclear energy liberation. Developments of radiation sources, including nuclear reactors, and charged-particle accelerators follow with simultaneous description on radiation measurement or detection technology. In medical fields, X-ray diagnosis, interventional radiology (IVR), nuclear medicine (PET and others), and radiation therapy are introduced. In pharmaceutical field, synthesis of labeled compounds and tracer techniques are explained. In industrial application, radiation-reinforced wires and heat-resistant cables whose economic effect can be estimated to amount to more than 10 12 yen, radiation mutation, food irradiation, and applied accelerators such as polymer modifications, decomposition of environmentally harmful substances, and ion-implantations important in semiconductor device fabrication. Finally, problems relating to general public such as radiation education and safety concept are also discussed. (S. Ohno)

TH-F-202-00: MRI for Radiation Therapy

International Nuclear Information System (INIS)

2016-01-01

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image-guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy. Learning Objectives: To learn basics of MR physics and understand the differences between various pulse sequences To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapy Partly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai

TH-F-202-00: MRI for Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

NONE

2016-06-15

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image-guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy. Learning Objectives: To learn basics of MR physics and understand the differences between various pulse sequences To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapy Partly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai.

Phase I and pharmacokinetic study of preirradiation chemotherapy with BCNU, cisplatin, etoposide, and accelerated radiation therapy in patients with high-grade glioma

International Nuclear Information System (INIS)

Rajkumar, S. Vincent; Buckner, Jan C.; Schomberg, Paula J.; Reid, Joel M.; Bagniewski, Pamela J.; Ames, Matthew M.; Cascino, Terrence L.; Marks, Randolph S.

1998-01-01

Purpose: We conducted a Phase I study of bischloroethylnitrosourea (BCNU), cisplatin, and oral etoposide administered prior to and during accelerated hyperfractionated radiation therapy in newly diagnosed high-grade glioma. Pharmacokinetic studies of oral etoposide were also done. Methods and Materials: Patients started chemotherapy after surgery but prior to definitive radiation therapy (160 cGy twice daily x 15 days; 4800 cGy total). Initial chemotherapy consisted of BCNU 40 mg/m 2 days 1-3, cisplatin 30 mg/m 2 days 1-3 and 29-31, and etoposide 50 mg orally days 1-14 and 29-42, repeated in 8 weeks concurrent with radiation therapy. BCNU 200 mg/m 2 every 8 weeks x 4 cycles was given after radiation therapy. Results: Sixteen patients, 5 with grade 3 anaplastic astrocytoma and 11 with glioblastoma were studied. Grade 3-4 leukopenia (38%) and thrombocytopenia (31%) were dose-limiting. Other toxicities were anorexia (81%), nausea (94%), emesis (56%), alopecia (88%), and ototoxicity (38%). The maximum tolerated dose was BCNU 40 mg/m 2 days 1-3, cisplatin 20 mg/m 2 days 1-3 and 29-31, and oral etoposide 50 mg days 1-21 and 29-49 prior to radiation therapy and repeated in 8 weeks with the start of radiation therapy followed by BCNU 200 mg/m 2 every 8 weeks for 4 cycles. Median time to progression and survival were 13 and 14 months respectively. Responses occurred in 2 of 9 (22%) patients with evaluable disease. In pharmacokinetic studies, all patients achieved plasma concentrations of >0.1 μg/ml etoposide (the in vitro radiosensitizing threshold), following a 50 mg oral dose. The mean ± SD 2 hr and 6 hr plasma concentrations were 0.92 ± 0.43 μg/ml and 0.36 ± 0.12 μg/ml, respectively. Estimated duration of exposure to >0.1 μg/ml etoposide was 10-17 hr. Conclusions: Preirradiation chemotherapy with BCNU, cisplatin, and oral etoposide with accelerated hyperfractionated radiation therapy in high-grade gliomas is feasible and merits further investigation. Sustained

The incidence of breast cancer following mantle field radiation therapy as a function of dose and technique

International Nuclear Information System (INIS)

Tinger, Alfred; Wasserman, Todd H.; Klein, Eric E.; Miller, Elizabeth A.; Roberts, Tracy; Piephoff, James V.; Kucik, Nancy A.

1997-01-01

Purpose: There is an increased incidence of breast cancer following mantle field radiation therapy for Hodgkin's disease (HD). We reviewed the experience at the Mallinckrodt Institute of Radiology (MIR) for radiation factors related to the development of breast cancer after mantle field radiation therapy for HD. Methods: The radiation therapy records of 152 women treated with mantle field irradiation for HD at MIR between 1966-1985 were reviewed for the development of breast cancer and treatment-related factors. All patients had a minimum of 5 years of follow-up. The treatment era (1966-1974 vs. 1975-1985), stage of HD, mediastinal dose, axillary dose, maximum dose from the anterior field (anterior d max dose), the anterior-posterior:posterior-anterior (AP:PA) ratio, age at the time of treatment, length of follow-up, and history of splenectomy were analyzed as possible contributing factors for the development of breast cancer. The observed number of breast cancers was compared to the expected number based on age-adjusted incidences from the Connecticut Tumor Registry. Results: Ten breast cancers occurred in the population. Eight involved an upper outer quadrant. In a multivariate analysis, the development of breast cancer was significantly associated with axillary dose. Patients in the early treatment era were at an increased risk for the development of breast cancer due to high anterior d max and breast doses from weighting the fields anteriorly on a low energy linear accelerator. The use of current radiation therapy techniques was not related to an increased risk of breast cancer with a median follow-up of 13 years. Conclusions: A high dose to the axilla and the anterior d max point is significantly associated with the development of breast cancer after mantle field irradiation for HD. Efforts to protect the breast from high doses will likely lessen the increased risk of breast cancer in women treated with radiation therapy for HD

Phase 1 Trial of Neoadjuvant Radiation Therapy Before Prostatectomy for High-Risk Prostate Cancer

International Nuclear Information System (INIS)

Koontz, Bridget F.; Quaranta, Brian P.; Pura, John A.; Lee, W.R.; Vujaskovic, Zeljko; Gerber, Leah; Haake, Michael; Anscher, Mitchell S.; Robertson, Cary N.; Polascik, Thomas J.; Moul, Judd W.

2013-01-01

Purpose: To evaluate, in a phase 1 study, the safety of neoadjuvant whole-pelvis radiation therapy (RT) administered immediately before radical prostatectomy in men with high-risk prostate cancer. Methods and Materials: Twelve men enrolled and completed a phase 1 single-institution trial between 2006 and 2010. Eligibility required a previously untreated diagnosis of localized but high-risk prostate cancer. Median follow-up was 46 months (range, 14-74 months). Radiation therapy was dose-escalated in a 3 × 3 design with dose levels of 39.6, 45, 50.4, and 54 Gy. The pelvic lymph nodes were treated up to 45 Gy with any additional dose given to the prostate and seminal vesicles. Radical prostatectomy was performed 4-8 weeks after RT completion. Primary outcome measure was intraoperative and postoperative day-30 morbidity. Secondary measures included late morbidity and oncologic outcomes. Results: No intraoperative morbidity was seen. Chronic urinary grade 2+ toxicity occurred in 42%; 2 patients (17%) developed a symptomatic urethral stricture requiring dilation. Two-year actuarial biochemical recurrence-free survival was 67% (95% confidence interval 34%-86%). Patients with pT3 or positive surgical margin treated with neoadjuvant RT had a trend for improved biochemical recurrence-free survival compared with a historical cohort with similar adverse factors. Conclusions: Neoadjuvant RT is feasible with moderate urinary morbidity. However, oncologic outcomes do not seem to be substantially different from those with selective postoperative RT. If this multimodal approach is further evaluated in a phase 2 setting, 54 Gy should be used in combination with neoadjuvant androgen deprivation therapy to improve biochemical outcomes

Phase 1 Trial of Neoadjuvant Radiation Therapy Before Prostatectomy for High-Risk Prostate Cancer

Energy Technology Data Exchange (ETDEWEB)

Koontz, Bridget F., E-mail: Bridget.Koontz@duke.edu [Department of Radiation Oncology, Duke Cancer Institute, Durham, North Carolina (United States); Duke Prostate Center, Duke Cancer Institute, Durham, North Carolina (United States); Quaranta, Brian P. [21st Century Oncology, Asheville, North Carolina (United States); Pura, John A. [Division of Biostatistics, Duke Cancer Institute, Durham, North Carolina (United States); Lee, W.R.; Vujaskovic, Zeljko [Department of Radiation Oncology, Duke Cancer Institute, Durham, North Carolina (United States); Duke Prostate Center, Duke Cancer Institute, Durham, North Carolina (United States); Gerber, Leah [Duke Prostate Center, Duke Cancer Institute, Durham, North Carolina (United States); Haake, Michael [Southeast Radiation Oncology, Charlotte, North Carolina (United States); Anscher, Mitchell S. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States); Robertson, Cary N.; Polascik, Thomas J.; Moul, Judd W. [Department of Surgery, Duke Cancer Institute, Durham, North Carolina (United States); Duke Prostate Center, Duke Cancer Institute, Durham, North Carolina (United States)

2013-09-01

Purpose: To evaluate, in a phase 1 study, the safety of neoadjuvant whole-pelvis radiation therapy (RT) administered immediately before radical prostatectomy in men with high-risk prostate cancer. Methods and Materials: Twelve men enrolled and completed a phase 1 single-institution trial between 2006 and 2010. Eligibility required a previously untreated diagnosis of localized but high-risk prostate cancer. Median follow-up was 46 months (range, 14-74 months). Radiation therapy was dose-escalated in a 3 × 3 design with dose levels of 39.6, 45, 50.4, and 54 Gy. The pelvic lymph nodes were treated up to 45 Gy with any additional dose given to the prostate and seminal vesicles. Radical prostatectomy was performed 4-8 weeks after RT completion. Primary outcome measure was intraoperative and postoperative day-30 morbidity. Secondary measures included late morbidity and oncologic outcomes. Results: No intraoperative morbidity was seen. Chronic urinary grade 2+ toxicity occurred in 42%; 2 patients (17%) developed a symptomatic urethral stricture requiring dilation. Two-year actuarial biochemical recurrence-free survival was 67% (95% confidence interval 34%-86%). Patients with pT3 or positive surgical margin treated with neoadjuvant RT had a trend for improved biochemical recurrence-free survival compared with a historical cohort with similar adverse factors. Conclusions: Neoadjuvant RT is feasible with moderate urinary morbidity. However, oncologic outcomes do not seem to be substantially different from those with selective postoperative RT. If this multimodal approach is further evaluated in a phase 2 setting, 54 Gy should be used in combination with neoadjuvant androgen deprivation therapy to improve biochemical outcomes.

On the origin of very-high-energy photons in astrophysics: a short introduction to acceleration and radiation physics

International Nuclear Information System (INIS)

Lemoine, M.; Pelletier, G.

2015-01-01

Powerful astrophysical sources produce non-thermal spectra of very-high-energy photons, with generic power-law distributions, through various radiative processes of charged particles, e.g., synchrotron radiation, inverse Compton processes, and hadronic interactions. Those charged particles have themselves been accelerated to ultra-relativistic energies in intense electromagnetic fields in the source. In many cases, the exact acceleration scheme is not known, but standard scenarios, such as Fermi mechanisms and reconnection processes are generally considered as prime suspects for the conversion of bulk kinetic or electromagnetic energy into a power law of supra-thermal particles. This paper proposes a short introduction to the various acceleration and radiative processes which shape the distributions of very-high-energy photons (E > 100 MeV) in astrophysics. (authors)

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.

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

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

Universality, maximum radiation, and absorption in high-energy collisions of black holes with spin.

Science.gov (United States)

Sperhake, Ulrich; Berti, Emanuele; Cardoso, Vitor; Pretorius, Frans

2013-07-26

We explore the impact of black hole spins on the dynamics of high-energy black hole collisions. We report results from numerical simulations with γ factors up to 2.49 and dimensionless spin parameter χ=+0.85, +0.6, 0, -0.6, -0.85. We find that the scattering threshold becomes independent of spin at large center-of-mass energies, confirming previous conjectures that structure does not matter in ultrarelativistic collisions. It has further been argued that in this limit all of the kinetic energy of the system may be radiated by fine tuning the impact parameter to threshold. On the contrary, we find that only about 60% of the kinetic energy is radiated for γ=2.49. By monitoring apparent horizons before and after scattering events we show that the "missing energy" is absorbed by the individual black holes in the encounter, and moreover the individual black-hole spins change significantly. We support this conclusion with perturbative calculations. An extrapolation of our results to the limit γ→∞ suggests that about half of the center-of-mass energy of the system can be emitted in gravitational radiation, while the rest must be converted into rest-mass and spin energy.

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

Effect of radiation therapy against intracranial hemangiopericytoma

Energy Technology Data Exchange (ETDEWEB)

Uemura, Shozaburo; Kuratsu, Jun-ichi; Hamada, Jun-ichiro; Yoshioka, Susumu; Kochi, Masato; Ushio, Yukitaka [Kumamoto Univ. (Japan). School of Medicine; Nakahara, Tadashi; Kishida, Katsuaki

1992-06-01

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).

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)

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.

Radiation processing of polymers with high energy electron beams: novel materials and processes

International Nuclear Information System (INIS)

Sarma, K.S.S.; Sabharwal, Sunil

2002-01-01

High-energy ionizing radiation available from electron beam (EB) accelerators has the ability to create extremely reactive species like free radicals or ions at room temperature or even at low temperature in any phase and in a variety of substrates without addition of external additives. This unique advantage of high energy has been utilized in the recent years to produce better quality materials in an environment friendly and cost-effective manner. The availability of high power and reliable EB accelerators has provided new tools to modify the materials and/or processes for a variety of applications. At BARC, a 2 MeV, 20 kW electron beam accelerator has been the nucleus of developing industrial applications of radiation processing in India for last 10 years. The focus has been on developing technologies that are of relevance to Indian socio-economic conditions and also provide economic benefits to the industry. In the areas of polymer processing industry, commercial success has already been achieved while for exploring its applications in the areas of food and agriculture and environment, technology demonstration plants are being set up. The current status of the programme, the new developments and future direction of radiation processing technology shall be presented in this paper. (author)

Intensity-modulated radiation therapy clinical evidence and techniques

CERN Document Server

Nishimura, Yasumasa

2015-01-01

Successful clinical use of intensity-modulated radiation therapy (IMRT) represents a significant advance in radiation oncology. Because IMRT can deliver high-dose radiation to a target with a reduced dose to the surrounding organs, it can improve the local control rate and reduce toxicities associated with radiation therapy. Since IMRT began being used in the mid-1990s, a large volume of clinical evidence of the advantages of IMRT has been collected. However, treatment planning and quality assurance (QA) of IMRT are complicated and difficult for the clinician and the medical physicist. This book, by authors renowned for their expertise in their fields, provides cumulative clinical evidence and appropriate techniques for IMRT for the clinician and the physicist. Part I deals with the foundations and techniques, history, principles, QA, treatment planning, radiobiology and related aspects of IMRT. Part II covers clinical applications with several case studies, describing contouring and dose distribution with cl...

Intra-oral cone radiation therapy for selected carcinomas of the oral cavity

International Nuclear Information System (INIS)

Wang, C.C.; Doppke, K.P.; Biggs, P.J.

1983-01-01

A study of 101 patients with early carcinomas of the oral cavity, T1 and T2, treated by external cobalt 60 beam and/or intra-oral cone (IOC) radiation therapy between 1964 through 1980 was made. The two year disease-free survival rate, including surgical salvage, was 88% and the local control rate was 85%. The incidence of radiation complications, i.e., soft tissue ulceration and/or osteoradionecrosis, was 14% and varied with various tumor sites and radiation doses delivered. The present review shows that local control and radiation complications are closely related to radiation doses and varies with different tumor sites of the oral cavity. Radiation therapy dosages expressed in terms of TDF values for these lesions are herein recommended. With proper selections of lesions arising from the oral cavity, combined external beam and IOC radiation therapy has been found extremely efficacious in achieving good local tumor control and high survival rates with excellent cosmetic and functional results and minimum radiation sequalae

Radiation therapy and late reactions in normal tissues

International Nuclear Information System (INIS)

Aoyama, Takashi; Kuroda, Yasumasa

1998-01-01

Recent developments in cancer therapy have made us increasingly aware that the quality of life of a patient is as valuable as other benefits received from therapy. This awareness leads to an emphasis on organ and/or function preservation in the course of therapy. In line with this new thinking, greater consideration is placed on radiation therapy as an appropriate modality of cancer therapy. Possible complications in normal tissues, especially those of late reaction type after the therapy must be overcome. This review, therefore, focuses on recent progress of studies on mechanisms of the complications of the late reaction type. An observation of a clinical case concerning a late reaction of spinal cord (radiation myelopathy) and surveys of experimental studies on the mechanisms of late reactions (including radiation pneumonitis and lung fibrosis, and radiation response of vascular endothelial cells) provide a hypothesis that apoptosis through the pathway starting with radiation-induced sphingomyelin hydrolysis may play an important role in causing a variety of late reactions. This insight is based on the fact that radiation also activates protein kinase C which appears to block apoptosis. The mechanisms of late reactions, therefore, may involve a balance between radiation-induced apoptotic death and its down regulation by suppressor mechanisms through protein kinase C. (author)

A current perspective on stereotactic body radiation therapy for pancreatic cancer

Directory of Open Access Journals (Sweden)

Hong JC

2016-10-01

Full Text Available Julian C Hong, Brian G Czito, Christopher G Willett, Manisha Palta Department of Radiation Oncology, Duke University, Durham, NC, USA Abstract: Pancreatic cancer is a formidable malignancy with poor outcomes. The majority of patients are unable to undergo resection, which remains the only potentially curative treatment option. The management of locally advanced (unresectable pancreatic cancer is controversial; however, treatment with either chemotherapy or chemoradiation is associated with high rates of local tumor progression and metastases development, resulting in low survival rates. An emerging local modality is stereotactic body radiation therapy (SBRT, which uses image-guided, conformal, high-dose radiation. SBRT has demonstrated promising local control rates and resultant quality of life with acceptable rates of toxicity. Over the past decade, increasing clinical experience and data have supported SBRT as a local treatment modality. Nevertheless, additional research is required to further evaluate the role of SBRT and improve upon the persistently poor outcomes associated with pancreatic cancer. This review discusses the existing clinical experience and technical implementation of SBRT for pancreatic cancer and highlights the directions for ongoing and future studies. Keywords: pancreatic cancer, stereotactic body radiation therapy, SBRT, radiation therapy

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

Comparison of acute and subacute genitourinary and gastrointestinal adverse events of radiotherapy for prostate cancer using intensity-modulated radiation therapy, three-dimensional conformal radiation therapy, permanent implant brachytherapy and high-dose-rate brachytherapy

NARCIS (Netherlands)

Morimoto, Masahiro; Yoshioka, Yasuo; Konishi, Koji; Isohashi, Fumiaki; Takahashi, Yutaka; Ogata, Toshiyuki; Koizumi, Masahiko; Teshima, Teruki; Bijl, Henk P; van der Schaaf, Arjen; Langendijk, Johannes A; Ogawa, Kazuhiko

2014-01-01

AIMS AND BACKGROUND: To examine acute and subacute urinary and rectal toxicity in patients with localized prostate cancer monotherapeutically treated with the following four radiotherapeutic techniques: intensity-modulated radiation therapy, three-dimensional conformal radiation therapy,

Radiative polarization in high-energy storage rings

International Nuclear Information System (INIS)

Mane, S.R.

1989-01-01

Electron and positron beams circulating in high-energy storage rings become spontaneously polarized by the emission of synchrotron radiation. The asymptotic degree of polarization that can be attained is strongly affected by so-called depolarizing resonances. Detailed experimental measurements of the polarization were made SPEAR about ten years ago, but due to lack of a suitable theory only a limited theoretical fit to the data has so far been achieved. The author presents a general formalism for calculating depolarizing resonances, which has been coded into a computer program called SMILE, and use it to fit the SPEAR data. By the use of suitable approximations, the author is able to fit both higher order and nonlinear resonances, and thereby to interpret many hitherto unexplained features in the data, and to resolve a puzzle concerning the asymmetry of certain resonance widths seen in the data. 18 refs., 2 figs

The use dibunol therapy for radiation injuries of the skin and mucous membranes

International Nuclear Information System (INIS)

Agafonova, G.B.; Barsel', V.A.; Sarkisyan, Yu.Kh.; Terekhova, G.S.; Podlyashchuk, E.L.; Ustinova, V.F.; AN SSSR, Moscow. Inst. Khimicheskoj Fiziki)

1983-01-01

There are presented the results of the use of dibunol in the form of liniment (1-10%) for the treatment of radiation cystitis and rectitis resulting from radiation therapy of small pelvic tumors, epidermitis and epithelitis that develop in the course of treatment of skin and lower lip tumors. A high efficacy of the drug in the therapy of radiation injury has been shown in 212 patients

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

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

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

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

International Nuclear Information System (INIS)

Jang, Joon Yung; Park, Soo Yun; Kim, Jong Sik; Choi, Byeong Gi; Song, Gi Won

2011-01-01

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.

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.

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

Radiative recombination of highly charged ions: Enhanced rates at low energies

International Nuclear Information System (INIS)

Frank, A.; Mueller, A.; Haselbauer, J.; Schennach, S.; Spies, W.; Uwira, O.; Wagner, M.

1992-01-01

In a single-pass merged-beams experiment employing a dense cold electron target recombination of highly charged ions is studied. Unexpected high recombination rates are observed at low energies E cm in the electron-ion center-of-mass frame. In particular, theoretical estimates for radiative recombination are dramatically exceeded by the experimental recombination rates at E cm =0 eV for U 28+ and for Au 25+ ions. Considerable rate enhancement is also observed for Ar 15+ . This points to a general phenomenon which has to be interpreted as a consequence of high electron densities, low electron beam temperatures, high ion charge states and presence of strong magnetic fields. (orig.)

Radiation therapy for primary undifferentiated carcinoma of the esophagus

International Nuclear Information System (INIS)

Ohno, Tatsuya; Yamakawa, Michitaka; Shiojima, Kazumi; Hasegawa, Masatoshi; Akimoto, Tetsuo; Nakayama, Yuko; Kitamoto, Yoshizumi; Mitsuhashi, Norio; Niibe, Hideo

1996-01-01

Eight patients with undifferentiated carcinoma of the esophagus were treated by radiation therapy. Loco-regional control was easily achieved by radiation therapy alone and no loco-regional recurrence was observed for six patients treated with total dose of more than 30 Gy. However four patients developed distant metastases and died of tumor. Median survival was 3.5 months with a range of 0 to 48 months. Only one patient is alive with no evidence of tumor for 48 months. Combination chemotherapy should be recommended for primary undifferentiated carcinoma of the esophagus because of having a high incidence of distant metastases. (author)

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.

Insufficiency fractures following radiation therapy for gynecologic malignancies

Energy Technology Data Exchange (ETDEWEB)

Ikushima, Hitoshi; Takegawa, Yoshihiro; Matsuki, Hirokazu; Yasuda, Hiroaki; Kawanaka, Takashi; Shiba, Atsushi; Kishida, Yoshiomi; Iwamoto, Seiji; Nishitani, Hiromu [Tokushima Univ. (Japan). School of Medicine

2002-12-01

The purpose of this study was to investigate the incidence, clinical and radiological findings of insufficiency fractures (IF) of the female pelvis following radiation therapy. We retrospectively reviewed the radiation oncology records of 108 patients with gynecologic malignancies who underwent external beam radiation therapy of the whole pelvis. All patients underwent conventional radiography and computed tomography (CT) scan every 6 months in follow-up after radiation therapy and magnetic resonance imaging (MRI) and radionuclide bone scan were added when the patients complained of pelvic pain. Thirteen of 108 patients (12%) developed IF in the irradiated field with a median interval of 6 months (range 3-51) from the completion of external beam radiation therapy. All patients who developed IF were postmenopausal women. Age of the patients who developed IF was significantly higher than that of the other patients. The parts of IF were sacroiliac joints, pubis, sacral body and 5th lumbar vertebra and six of 14 patients had multiple lesions. Treatment with rest and nonsteroidal anti-inflammatory drugs lead to symptomatic relief in all patients, although symptoms lasted from 3 to 20 months. Radiation-induced pelvic IF following radiation therapy for gynecologic malignancies were frequently observed in the post-menopausal patients within 1 year after external beam radiation therapy. Symmetrical fractures of the bilateral sacroiliac joint and pubis were the characteristic pattern of pelvic IF. All patients healed with conservative treatment, and nobody became non-ambulant. (author)

Comparing two strategies of dynamic intensity modulated radiation therapy (dIMRT) with 3-dimensional conformal radiation therapy (3DCRT) in the hypofractionated treatment of high-risk prostate cancer

International Nuclear Information System (INIS)

Yuen, Jasper; Rodrigues, George; Trenka, Kristina; Coad, Terry; Yartsev, Slav; D'Souza, David; Lock, Michael; Bauman, Glenn

2008-01-01

To compare two strategies of dynamic intensity modulated radiation therapy (dIMRT) with 3-dimensional conformal radiation therapy (3DCRT) in the setting of hypofractionated high-risk prostate cancer treatment. 3DCRT and dIMRT/Helical Tomotherapy(HT) planning with 10 CT datasets was undertaken to deliver 68 Gy in 25 fractions (prostate) and simultaneously delivering 45 Gy in 25 fractions (pelvic lymph node targets) in a single phase. The paradigms of pelvic vessel targeting (iliac vessels with margin are used to target pelvic nodes) and conformal normal tissue avoidance (treated soft tissues of the pelvis while limiting dose to identified pelvic critical structures) were assessed compared to 3DCRT controls. Both dIMRT/HT and 3DCRT solutions were compared to each other using repeated measures ANOVA and post-hoc paired t-tests. When compared to conformal pelvic vessel targeting, conformal normal tissue avoidance delivered more homogenous PTV delivery (2/2 t-test comparisons; p < 0.001), similar nodal coverage (8/8 t-test comparisons; p = ns), higher and more homogenous pelvic tissue dose (6/6 t-test comparisons; p < 0.03), at the cost of slightly higher critical structure dose (D dose , 1–3 Gy over 5/10 dose points; p < 0.03). The dIMRT/HT approaches were superior to 3DCRT in sparing organs at risk (22/24 t-test comparisons; p < 0.05). dIMRT/HT nodal and pelvic targeting is superior to 3DCRT in dose delivery and critical structure sparing in the setting of hypofractionation for high-risk prostate cancer. The pelvic targeting paradigm is a potential solution to deliver highly conformal pelvic radiation treatment in the setting of nodal location uncertainty in prostate cancer and other pelvic malignancies

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

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

International Nuclear Information System (INIS)

Chadwick, M.B.

1998-01-01

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

The penetration, diffusion and energy deposition of high-energy photon in layered media

International Nuclear Information System (INIS)

Zhengming, Luo; Chengjun, Gou; Laub, Wolfram

2002-01-01

This paper presents a new theory for calculating the transport of high-energy photons and their secondary charged particles. We call this new algorithm characteristic line method, which is completely analytic. Using this new method we can not only accurately calculate the transport behavior of energetic photons, but also precisely describes the transport behavior and energy deposition of secondary electrons, photoelectrons, Compton recoil electrons and positron-electron pairs. Its calculation efficiency is much higher than the Monte Carlo method's. The theory can be directly applied to layered media situation and obtain a pencil-beam-modeled solution. Therefore, it may be applied to clinical applications for radiation therapy

New self-similar radiation-hydrodynamics solutions in the high-energy density, equilibrium diffusion limit

International Nuclear Information System (INIS)

Lane, Taylor K; McClarren, Ryan G

2013-01-01

This work presents semi-analytic solutions to a radiation-hydrodynamics problem of a radiation source driving an initially cold medium. Our solutions are in the equilibrium diffusion limit, include material motion and allow for radiation-dominated situations where the radiation energy is comparable to (or greater than) the material internal energy density. As such, this work is a generalization of the classical Marshak wave problem that assumes no material motion and that the radiation energy is negligible. Including radiation energy density in the model serves to slow down the wave propagation. The solutions provide insight into the impact of radiation energy and material motion, as well as present a novel verification test for radiation transport packages. As a verification test, the solution exercises the radiation–matter coupling terms and their v/c treatment without needing a hydrodynamics solve. An example comparison between the self-similar solution and a numerical code is given. Tables of the self-similar solutions are also provided. (paper)

EFFECTS OF SPIN ON HIGH-ENERGY RADIATION FROM ACCRETING BLACK HOLES

Energy Technology Data Exchange (ETDEWEB)

O’ Riordan, Michael; Pe’er, Asaf [Physics Department, University College Cork, Cork (Ireland); McKinney, Jonathan C., E-mail: michael_oriordan@umail.ucc.ie [Department of Physics and Joint Space-Science Institute, University of Maryland, College Park, MD 20742 (United States)

2016-11-01

Observations of jets in X-ray binaries show a correlation between radio power and black hole spin. This correlation, if confirmed, points toward the idea that relativistic jets may be powered by the rotational energy of black holes. In order to examine this further, we perform general relativistic radiative transport calculations on magnetically arrested accretion flows, which are known to produce powerful jets via the Blandford–Znajek (BZ) mechanism. We find that the X-ray and γ -ray emission strongly depend on spin and inclination angle. Surprisingly, the high-energy power does not show the same dependence on spin as the BZ jet power, but instead can be understood as a redshift effect. In particular, photons observed perpendicular to the spin axis suffer little net redshift until originating from close to the horizon. Such observers see deeper into the hot, dense, highly magnetized inner disk region. This effect is largest for rapidly rotating black holes due to a combination of frame dragging and decreasing horizon radius. While the X-ray emission is dominated by the near horizon region, the near-infrared (NIR) radiation originates at larger radii. Therefore, the ratio of X-ray to NIR power is an observational signature of black hole spin.

Radiation therapy of Graves' ophthalmopathy. 2; Therapy started time

Energy Technology Data Exchange (ETDEWEB)

Kawamura, Toshinori; Koga, Sukehiko (Fujita Health Univ., Toyoake, Aichi (Japan). School of Medicine)

1994-04-01

The difference in the improvement of exophthalmos according to the period of starting radiation therapy was investigated for 26 patients of thyroid ophthalmopathy, also taking thyroidism during radiation into consideration. A 4 MV X-ray was used to a total dose of 20 Gy per 2 weeks. The treatment value tended to be better for the patients in whom the period from the appearance of exophthalmos in an euthyroid condition to the start of radiation was less than 12 months; those of a longer period showed poorer improvement. Radiation treatment of a hyperthyroid condition also showed poor results and it was thought it was not an adequately long enough period for the radiation to take effect. As a result, it was considered that the radiation therapy shall be advantageous if started within 12 months after the appearance of exophthalmos in an euthyroid condition. (author).

Effect of high-energy radiation on the rheological characteristics and structure of liquid rubbers

International Nuclear Information System (INIS)

Govorkov, A.T.; Zaitseva, V.I.; Muryshkin, D.L.; Safonov, Yu.N.

1987-01-01

The effect of high-energy radiation (γ-radiation and accelerated electrons) on liquid polybutadiene and polyisoprene rubbers (SKD, SKD-KTR, SKN) and butyl rubber (BR) was studied by IR and EPR spectroscopy, rheoviscosimetry, and chemical analysis. Newtonian flow was conserved in the rubbers under irradiation. The activation energy of viscous flow was unchanged, evidence of an increase in the contour length of the macromolecules without significant branching and cross-linking at the initial stages of the irradiation. A quantitative relationship was established between the rubber's dynamic viscosity and the absorbed dose, and features of the structure-formation mechanism in the liquid rubbers were determined

Proceedings of the third specialists` meeting on high energy nuclear data

Energy Technology Data Exchange (ETDEWEB)

Fukahori, Tokio [ed.

1998-11-01

This report is the Proceedings of the Third Specialists` Meeting on High Energy Nuclear Data. The meeting was held on March 30-31, 1998, at the Tokai Research Establishment of Japan Atomic Energy Research Institute with the participation of forty-odd specialists, who were the evaluators, theorists, experimentalists and users of high energy nuclear data including the members of the Japanese Nuclear Data Committee. The need of the high energy nuclear data up to a few Gev has been stressed in the meeting for many applications, such as spallation neutron sources for radioactive waste treatment, accelerator shielding design, medical isotope production, radiation therapy, the effects of space radiation on astronauts and their equipments, and the cosmic history of meteorites and other galactic substances. Since the Second Specialists` Meeting in 1995, such an evaluation activity in Japan has been grown and the results are accumulated. Foreign activities of high energy nuclear data evaluation are also being increased. According to the above situation, with the view point of reviewing and validating an evaluated high energy nuclear data file, project of high energy nuclear data file production, differential and integral experiments, status of evaluation and reviewing methods, processing and transport calculation methods, benchmark tests, international trends, etc. were discussed. The 16 of the presented papers are indexed individually. (J.P.N.)

Measurement and analysis of high energy radiation through activation detectors. Application in dosimetry

International Nuclear Information System (INIS)

Sklavenitis, L.

1967-10-01

This work is concerned with the possibility of measurement and analysis of radiation fluences within objects of small volume submitted to a high energy proton beam. The first part, consecrated to the establishment of a method of analysis, comprises a detailed study of the radiation nature and energy spectra as well as of the various dosimetry methods. In order to select a group of detectors, high energy nuclear reactions were systematically studied and for some of them cross sections were measured or calculated: for example the cross section of the reaction 11 B (p,n) 11 C between 150 and 3000 MeV and of the reaction 34 S (p,2pn) 32 P between 50 and 3000 MeV. The second part is relative to the application of the fore-mentioned analysis to radiation within a tissue equivalent phantom irradiated by 3 GeV protons. This analysis is sufficiently detailed to allow the reconstitution of the absorbed doses, the dose equivalent and, contingent on a better knowledge of the dose due to heavy particles, the quality factors. It allowed also to follow the evolution of the various dosimetric data as a function of the depth inside the phantom and to verify calculations already done by other researchers. The comparison of the measured doses and the corresponding detector activities revealed the possibility that some detectors could give directly the absorbed dose, or even the dose equivalent, by a simple activity measurement. (author) [fr

Radiation therapy for metastatic lesions from breast cancer. Breast cancer metastasis to bone

International Nuclear Information System (INIS)

Hayashi, Shinya; Hoshi, Hiroaki

2000-01-01

This paper summarizes radiation therapy in the treatment of bone metastases from breast cancer. Bone metastasis occurs in approximately 70% of breast cancer patients, and the goals of radiation therapy for bone metastasis are: palliation of pain, prevention and treatment of neuropathic symptoms, and prevention of pathologic fractures. The prognosis of bone metastasis from breast cancer is known to be better than that of bone metastasis from other solid tumors. Local-field radiation, hemibody (or wide-field) radiation, and systemic radionuclide treatment are the major methods of radiation therapy for pain palliation. Although many studies have shown that breast cancer is more responsive to radiation therapy for pain palliation than other solid tumors, some studies found no significant difference. Local-field radiation therapy, which includes multi-fraction irradiation and single-fraction irradiation, is currently the most generally used method of radiotherapy for pain palliation. Pain palliation has been reported to be achieved in approximately 80% to 90% of patients treated with local-field external beam irradiation. Three types of multi-fraction irradiation therapy are administered depending on the prognosis: high-dose fraction irradiation (36-50 Gy/12-25 Fr/2.4-5 wk), short-course irradiation (20-30 Gy/10-15 Fr/2-3 wk), and ultra-short-course irradiation (15-25 Gy/2-5 Fr/1 wk). The most common irradiation schedule is 30 Gy/10 Fr/2 wk. Although many reports indicate no significant difference in pain palliation according to the dose, the percentage of patients who show a complete cure is significantly higher in those treated with doses of 30 Gy or more, and thus the total irradiation dose should be at least 30 Gy. High-dose fraction irradiation is indicated for patients with an expected survival time of 6 months or more while short-course or single-fraction irradiation is indicated for those with an expected survival time of 3 months or more. Single

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

Energy Technology Data Exchange (ETDEWEB)

Ding, Xuanfeng; Dionisi, Francesco; Tang, Shikui; Ingram, Mark; Hung, Chun-Yu; Prionas, Evangelos; Lichtenwalner, Phil; Butterwick, Ian; Zhai, Huifang; Yin, Lingshu; Lin, Haibo; Kassaee, Alireza; Avery, Stephen, E-mail: stephen.avery@uphs.upenn.edu

2014-07-01

With traditional photon therapy to treat large postoperative pancreatic target volume, it often leads to poor tolerance of the therapy delivered and may contribute to interrupted treatment course. This study was performed to evaluate the potential advantage of using passive-scattering (PS) and modulated-scanning (MS) proton therapy (PT) to reduce normal tissue exposure in postoperative pancreatic cancer treatment. A total of 11 patients with postoperative pancreatic cancer who had been previously treated with PS PT in University of Pennsylvania Roberts Proton Therapy Center from 2010 to 2013 were identified. The clinical target volume (CTV) includes the pancreatic tumor bed as well as the adjacent high-risk nodal areas. Internal (iCTV) was generated from 4-dimensional (4D) computed tomography (CT), taking into account target motion from breathing cycle. Three-field and 4-field 3D conformal radiation therapy (3DCRT), 5-field intensity-modulated radiation therapy, 2-arc volumetric-modulated radiation therapy, and 2-field PS and MS PT were created on the patients’ average CT. All the plans delivered 50.4 Gy to the planning target volume (PTV). Overall, 98% of PTV was covered by 95% of the prescription dose and 99% of iCTV received 98% prescription dose. The results show that all the proton plans offer significant lower doses to the left kidney (mean and V{sub 18} {sub Gy}), stomach (mean and V{sub 20} {sub Gy}), and cord (maximum dose) compared with all the photon plans, except 3-field 3DCRT in cord maximum dose. In addition, MS PT also provides lower doses to the right kidney (mean and V{sub 18} {sub Gy}), liver (mean dose), total bowel (V{sub 20} {sub Gy} and mean dose), and small bowel (V{sub 15} {sub Gy} absolute volume ratio) compared with all the photon plans and PS PT. The dosimetric advantage of PT points to the possibility of treating tumor bed and comprehensive nodal areas while providing a more tolerable treatment course that could be used for dose

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

International Nuclear Information System (INIS)

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

2014-01-01

With traditional photon therapy to treat large postoperative pancreatic target volume, it often leads to poor tolerance of the therapy delivered and may contribute to interrupted treatment course. This study was performed to evaluate the potential advantage of using passive-scattering (PS) and modulated-scanning (MS) proton therapy (PT) to reduce normal tissue exposure in postoperative pancreatic cancer treatment. A total of 11 patients with postoperative pancreatic cancer who had been previously treated with PS PT in University of Pennsylvania Roberts Proton Therapy Center from 2010 to 2013 were identified. The clinical target volume (CTV) includes the pancreatic tumor bed as well as the adjacent high-risk nodal areas. Internal (iCTV) was generated from 4-dimensional (4D) computed tomography (CT), taking into account target motion from breathing cycle. Three-field and 4-field 3D conformal radiation therapy (3DCRT), 5-field intensity-modulated radiation therapy, 2-arc volumetric-modulated radiation therapy, and 2-field PS and MS PT were created on the patients’ average CT. All the plans delivered 50.4 Gy to the planning target volume (PTV). Overall, 98% of PTV was covered by 95% of the prescription dose and 99% of iCTV received 98% prescription dose. The results show that all the proton plans offer significant lower doses to the left kidney (mean and V 18 Gy ), stomach (mean and V 20 Gy ), and cord (maximum dose) compared with all the photon plans, except 3-field 3DCRT in cord maximum dose. In addition, MS PT also provides lower doses to the right kidney (mean and V 18 Gy ), liver (mean dose), total bowel (V 20 Gy and mean dose), and small bowel (V 15 Gy absolute volume ratio) compared with all the photon plans and PS PT. The dosimetric advantage of PT points to the possibility of treating tumor bed and comprehensive nodal areas while providing a more tolerable treatment course that could be used for dose escalation and combining with radiosensitizing

Hypofractionated High-Dose Radiation Therapy for Prostate Cancer: Long-Term Results of a Multi-Institutional Phase II Trial

Energy Technology Data Exchange (ETDEWEB)

Fonteyne, Valerie, E-mail: valerie.fonteyne@uzgent.be [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium); Soete, Guy [Department of Radiotherapy, Universitair Ziekenhuis Brussels, Jette (Belgium); Arcangeli, Stefano [Department of Radiotherapy, Regina Elena National Cancer Institute, Rome (Italy); De Neve, Wilfried [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium); Rappe, Bernard [Department of Urology, Algemeen Stedelijk Ziekenhuis, Aalst (Belgium); Storme, Guy [Department of Radiotherapy, Universitair Ziekenhuis Brussels, Jette (Belgium); Strigari, Lidia [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome (Italy); Arcangeli, Giorgio [Department of Radiotherapy, Regina Elena National Cancer Institute, Rome (Italy); De Meerleer, Gert [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium)

2012-11-15

Purpose: To report late gastrointestinal (GI) and genitourinary (GU) toxicity, biochemical and clinical outcomes, and overall survival after hypofractionated radiation therapy for prostate cancer (PC). Methods and Materials: Three institutions included 113 patients with T1 to T3N0M0 PC in a phase II study. Patients were treated with 56 Gy in 16 fractions over 4 weeks. Late toxicity was scored using Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria extended with additional symptoms. Biochemical outcome was reported according to the Phoenix definition for biochemical failure. Results: The incidence of late GI and GU toxicity was low. The 3-year actuarial risk of developing late GU and GI toxicity of grade {>=}2 was 13% and 8% respectively. Five-year biochemical non-evidence of disease (bNED) was 94%. Risk group, T stage, and deviation from planned hormone treatment were significant predictive factors for bNED. Deviation from hormone treatment remained significant in multivariate analysis. Five-year clinical non evidence of disease and overall survival was 95% and 91% respectively. No patient died from PC. Conclusions: Hypofractionated high-dose radiation therapy is a valuable treatment option for patients with PC, with excellent biochemical and clinical outcome and low toxicity.

High-energy radiation from collisions of high-velocity clouds and the Galactic disc

Science.gov (United States)

del Valle, Maria V.; Müller, A. L.; Romero, G. E.

2018-04-01

High-velocity clouds (HVCs) are interstellar clouds of atomic hydrogen that do not follow normal Galactic rotation and have velocities of a several hundred kilometres per second. A considerable number of these clouds are falling down towards the Galactic disc. HVCs form large and massive complexes, so if they collide with the disc a great amount of energy would be released into the interstellar medium. The cloud-disc interaction produces two shocks: one propagates through the cloud and the other through the disc. The properties of these shocks depend mainly on the cloud velocity and the disc-cloud density ratio. In this work, we study the conditions necessary for these shocks to accelerate particles by diffusive shock acceleration and we study the non-thermal radiation that is produced. We analyse particle acceleration in both the cloud and disc shocks. Solving a time-dependent two-dimensional transport equation for both relativistic electrons and protons, we obtain particle distributions and non-thermal spectral energy distributions. In a shocked cloud, significant synchrotron radio emission is produced along with soft gamma rays. In the case of acceleration in the shocked disc, the non-thermal radiation is stronger; the gamma rays, of leptonic origin, might be detectable with current instruments. A large number of protons are injected into the Galactic interstellar medium, and locally exceed the cosmic ray background. We conclude that under adequate conditions the contribution from HVC-disc collisions to the galactic population of relativistic particles and the associated extended non-thermal radiation might be important.

Higgs radiation off top particles in high-energy e+e- colliders

International Nuclear Information System (INIS)

Djouadi, A.; Technische Hochschule Aachen; Kalinowski, J.; Zerwas, P.M.

1991-10-01

Higgs particles can be radiated off heavy top quarks which will be produced copiously in high energy e + e - colliders. This process can be used to measure the Higgs-top quark coupling. We present the cross section for the production of Higgs bosons in the Standard Model. In addition we have studied the production of neutral and charged Higgs particles in association with heavy fermions in the Minimal Supersymmetric Standard Model. (orig.)

Particle therapy for noncancer diseases

Energy Technology Data Exchange (ETDEWEB)

Bert, Christoph; Engenhart-Cabillic, Rita; Durante, Marco [GSI Helmholtzzentrum fuer Schwerionenforschung, Biophysics Department, Planckstrasse 1, 64291 Darmstadt (Germany); Philipps-University Marburg, Center for Radiology, Department of Radiation Therapy, Baldinger Strasse, 35043 Marburg (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Biophysics Department, Planckstrasse 1, 64291 Darmstadt (Germany); Technische Universitaet Darmstadt, Institut fuer Festkoerperphysik, Hochschulstrasse 3, 64289 Darmstadt (Germany) and Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany)

2012-04-15

Radiation therapy using high-energy charged particles is generally acknowledged as a powerful new technique in cancer treatment. However, particle therapy in oncology is still controversial, specifically because it is unclear whether the putative clinical advantages justify the high additional costs. However, particle therapy can find important applications in the management of noncancer diseases, especially in radiosurgery. Extension to other diseases and targets (both cranial and extracranial) may widen the applications of the technique and decrease the cost/benefit ratio of the accelerator facilities. Future challenges in this field include the use of different particles and energies, motion management in particle body radiotherapy and extension to new targets currently treated by catheter ablation (atrial fibrillation and renal denervation) or stereotactic radiation therapy (trigeminal neuralgia, epilepsy, and macular degeneration). Particle body radiosurgery could be a future key application of accelerator-based particle therapy facilities in 10 years from today.

Detoxication and antiproteolytic therapy of radiation complications

International Nuclear Information System (INIS)

Yakhontov, N.E.; Klimov, I.A.; Lavrikova, L.P.; Martynov, A.D.; Provorova, T.P.; Serdyukov, A.S.; Shestakov, A.F.

1984-01-01

49 patients with uterine cervix and ovarian carcinomas were treated with detoxication and antiproteolytic therapy of radiation-induced side-effects. The therapy permits to complete without interruption the remote gamma-therapy course and to reduce patients in-hospital periods by 10+- 1 days. The prescription of hemoder intravenous injection in a dose of 450 ml and contrical intramuscular injection (10000 AtrE) in cases of pronounced manifestations of radiation-induced side-effects (asthenia, leukopenia, enterocolitis) for 3 days should be considered an efficient therapy

Design principles and clinical possibilities with a new generation of radiation therapy equipment

Energy Technology Data Exchange (ETDEWEB)

Ruden, B P [Department of Hospital physics Karolinska institute, (Sudan)

1997-12-31

The main steps in the development of isocentric megavoltage external beam radiation therapy machines are briefly reviewed identifying three principal types or generations of equipment to date. The new fourth generation of equipment presented here is characterized by considerably increased flexibility in dose delivery through the use of scanned elementary electron and photon beams of very high quality. Furthermore, the wide energy range and the possibility of using high resolution multi leaf collimation with all beam modalities makes it possible to simplify irradiation techniques and increase the accuracy in dose delivery. The main design features are described including a dual magnet scanning system, a photon beam purging magnet, a helium atmosphere in the treatment head, a beam`s eye view video read-out system of the collimator setting and a radiotherapeutic computed tomography facility. Some of the clinical applications of this new type of radiation therapy machine are finally reviewed, such as the ease of performance, became flattening, beam filtering and compensation, and the simplification of many treatment techniques using the wide spectrum of high quality electron and photon beams. Finally, the interesting possibility of doing conformation and more general isocentric treatments with non-uniform beams using the multi leaf collimator and the scanning systems are demonstrated. 9 figs., 1 tab.

Electron Paramagnetic Resonance pO2 Image Tumor Oxygen-Guided Radiation Therapy Optimization.

Science.gov (United States)

Epel, Boris; Maggio, Matt; Pelizzari, Charles; Halpern, Howard J

2017-01-01

Modern standards for radiation treatment do not take into account tumor oxygenation for radiation treatment planning. Strong correlation between tumor oxygenation and radiation treatment success suggests that oxygen-guided radiation therapy (OGRT) may be a promising enhancement of cancer radiation treatment. We have developed an OGRT protocol for rodents. Electron paramagnetic resonance (EPR) imaging is used for recording oxygen maps with high spatial resolution and excellent accuracy better than 1 torr. Radiation is delivered with an animal intensity modulated radiation therapy (IMRT) XRAD225Cx micro-CT/ therapy system. The radiation plan is delivered in two steps. First, a uniform 15% tumor control dose (TCD 15 ) is delivered to the whole tumor. In the second step, an additional booster dose amounting to the difference between TCD 98 and TCD 15 is delivered to radio-resistant, hypoxic tumor regions. Delivery of the booster dose is performed using a multiport conformal beam protocol. For radiation beam shaping we used individual radiation blocks 3D-printed from tungsten infused ABS polymer. Calculation of beam geometry and the production of blocks is performed next to the EPR imager, immediately after oxygen imaging. Preliminary results demonstrate the sub-millimeter precision of the radiation delivery and high dose accuracy. The efficacy of the radiation treatment is currently being tested on syngeneic FSa fibrosarcoma tumors grown in the legs of C3H mice.

Preliminary results of concurrent chemotherapy and radiation therapy using high-dose-rate brachytherapy for cervical cancer

Energy Technology Data Exchange (ETDEWEB)

Lee, Kyung Ja; Lee, Ji Hye; Lee, Re Na; Suh, Hyun Suk [Ewha Womans University College of Medicine, Seoul (Korea, Republic of)

2006-09-15

To determine the efficacy and safety of concurrent chemotherapy and radiation therapy with high-dose-rate brachytherapy for cervical cancer. From January 2001 to December 2002, 30 patients with cervical cancer were treated with concurrent chemotherapy (cisplatin and 5-FU) and definitive radiation therapy. The median age was 58 (range 34 {approx} 74) year old. The pathology of the biopsy sections was squamous cell carcinoma in 29 patients and one was adenocarcinoma. The distribution to FIGO staging system was as follow: stage IB, 7 (23%); IIA, 3 (10%); IIB, 12 (40%); IIIA, 3 (10%); IIIB, 5 (17%). All patients received pelvic external beam irradiation (EBRT) to a total dose of 45 {approx} 50.4 Gy (median: 50.4 Gy) over 5 {approx} 5.5 weeks. Ir-192 HDR intracavity brachytherapy (ICBT) was given after a total dose of 41.1 Gy. HDR-ICBT was performed twice a week, with a fraction point. A dose of 4 Gy and median dose to point A was 28 Gy (range: 16 {approx} 32 Gy) in 7 fractions. The median cumulative biologic effective dose (BED) at point A (EBRT + ICBT) was 88 Gy{sub 10} (range:77 {approx} 94 Gy{sub 10}). The median cumulative BED at ICRU 38 reference point (EBRT + ICBT) was 131 Gy{sub 3} (range: 122 {approx} 140 Gy{sub 3}) at point A, 109 Gy{sub 3} (range:88{approx} 125 Gy{sub 3}) at the rectum and 111 Gy{sub 3} (range: 91 {approx} 123 Gy{sub 3}) at the urinary bladder. Cisplatin (60 mg/m{sup 2}) and 5-FU (1,000 mg/m{sup 2}) was administered intravenously at 2 weeks interval from the first day of radiation for median 5 (range:2 {approx} 6) cycles. The assessment was performed at 1 month after completion of radiation therapy by clinical examination and CT scan. The median follow-up time was 36 months (range:8{approx} 50 months). The complete response rate after concurrent chemo radiation therapy was 93.3%. The 3-yr actuarial pelvic control rate was 87% and 3-yr actuarial overall survival and disease-free survival rate was 93% and 87%, respectively. The local failure

Preliminary results of concurrent chemotherapy and radiation therapy using high-dose-rate brachytherapy for cervical cancer

International Nuclear Information System (INIS)

Lee, Kyung Ja; Lee, Ji Hye; Lee, Re Na; Suh, Hyun Suk

2006-01-01

To determine the efficacy and safety of concurrent chemotherapy and radiation therapy with high-dose-rate brachytherapy for cervical cancer. From January 2001 to December 2002, 30 patients with cervical cancer were treated with concurrent chemotherapy (cisplatin and 5-FU) and definitive radiation therapy. The median age was 58 (range 34 ∼ 74) year old. The pathology of the biopsy sections was squamous cell carcinoma in 29 patients and one was adenocarcinoma. The distribution to FIGO staging system was as follow: stage IB, 7 (23%); IIA, 3 (10%); IIB, 12 (40%); IIIA, 3 (10%); IIIB, 5 (17%). All patients received pelvic external beam irradiation (EBRT) to a total dose of 45 ∼ 50.4 Gy (median: 50.4 Gy) over 5 ∼ 5.5 weeks. Ir-192 HDR intracavity brachytherapy (ICBT) was given after a total dose of 41.1 Gy. HDR-ICBT was performed twice a week, with a fraction point. A dose of 4 Gy and median dose to point A was 28 Gy (range: 16 ∼ 32 Gy) in 7 fractions. The median cumulative biologic effective dose (BED) at point A (EBRT + ICBT) was 88 Gy 10 (range:77 ∼ 94 Gy 10 ). The median cumulative BED at ICRU 38 reference point (EBRT + ICBT) was 131 Gy 3 (range: 122 ∼ 140 Gy 3 ) at point A, 109 Gy 3 (range:88∼ 125 Gy 3 ) at the rectum and 111 Gy 3 (range: 91 ∼ 123 Gy 3 ) at the urinary bladder. Cisplatin (60 mg/m 2 ) and 5-FU (1,000 mg/m 2 ) was administered intravenously at 2 weeks interval from the first day of radiation for median 5 (range:2 ∼ 6) cycles. The assessment was performed at 1 month after completion of radiation therapy by clinical examination and CT scan. The median follow-up time was 36 months (range:8∼ 50 months). The complete response rate after concurrent chemo radiation therapy was 93.3%. The 3-yr actuarial pelvic control rate was 87% and 3-yr actuarial overall survival and disease-free survival rate was 93% and 87%, respectively. The local failure rate was 13% and distant metastatic rate was 3.3%. The crude rate of minor hematologic

The Role of Nuclear Fragmentation in Particle Therapy and Space Radiation Protection.

Science.gov (United States)

Zeitlin, Cary; La Tessa, Chiara

2016-01-01

The transport of the so-called HZE particles (those having high charge, Z, and energy, E) through matter is crucially important both in space radiation protection and in the clinical setting where heavy ions are used for cancer treatment. HZE particles are usually considered those having Z > 1, though sometimes Z > 2 is meant. Transport physics is governed by two types of interactions, electromagnetic (ionization energy loss) and nuclear. Models of transport, such as those used in treatment planning and space mission planning must account for both effects in detail. The theory of electromagnetic interactions is well developed, but nucleus-nucleus collisions are so complex that no fundamental physical theory currently describes them. Instead, interaction models are generally anchored to experimental data, which in some areas are far from complete. The lack of fundamental physics knowledge introduces uncertainties in the calculations of exposures and their associated risks. These uncertainties are greatly compounded by the much larger uncertainties in biological response to HZE particles. In this article, we discuss the role of nucleus-nucleus interactions in heavy charged particle therapy and in deep space, where astronauts will receive a chronic low dose from galactic cosmic rays (GCRs) and potentially higher short-term doses from sporadic, unpredictable solar energetic particles (SEPs). GCRs include HZE particles; SEPs typically do not and we, therefore, exclude them from consideration in this article. Nucleus-nucleus collisions can result in the breakup of heavy ions into lighter ions. In space, this is generally beneficial because dose and dose equivalent are, on the whole, reduced in the process. The GCRs can be considered a radiation field with a significant high-LET component; when they pass through matter, the high-LET component is attenuated, at the cost of a slight increase in the low-LET component. Not only are the standard measures of risk

Radiation therapy in patients with hematologic diseases

International Nuclear Information System (INIS)

Hennequin, C.; Maylin, C.

1995-01-01

Radiation therapy has a significant place in the treatment of hematologic diseases. Irradiation is a key component of the treatment strategy for Hodgkin's disease and has benefited from clinical studies aimed at improving its therapeutic index. There have been many recent improvements, in particular with regard to accuracy of techniques, imagery, dosimetry, and implementation of quality-control procedures. In localized non-Hodgkin's lymphoma, the gold-standard treatment is radiation therapy coupled with a short course of chemotherapy. In contrast, the place of irradiation in disseminated lymphomas remains to be defined. Prophylactic irradiation of the brain is still used in patients with acute lymphoblastic leukemia. Radiation therapy is of value as palliative treatment of bone lesions of myeloma, in chemo-resistant lymphomas, and in relapses of leukemia. Total body irradiation is a cumbersome but irreplaceable method, which has also benefited from recent clinical and biological studies. Optimal radiation therapy with the best possible therapeutic index requires adequate technological and human resources. (authors). 30 refs., 1 tab

Perspectives on High-Energy-Density Physics

Science.gov (United States)

Drake, R. Paul

2008-11-01

Much of 21st century plasma physics will involve work to produce, understand, control, and exploit very non-traditional plasmas. High-energy density (HED) plasmas are often examples, variously involving strong Coulomb interactions and few particles per Debeye sphere, dominant radiation effects, strongly relativistic effects, or strongly quantum-mechanical behavior. Indeed, these and other modern plasma systems often fall outside the early standard theoretical definitions of ``plasma''. This presentation will focus on two types of HED plasmas that exhibit non-traditional behavior. Our first example will be the plasmas produced by extremely strong shock waves. Shock waves are present across the entire realm of plasma densities, often in space or astrophysical contexts. HED shock waves (at pressures > 1 Mbar) enable studies in many areas, from equations of state to hydrodynamics to radiation hydrodynamics. We will specifically consider strongly radiative shocks, in which the radiative energy fluxes are comparable to the mechanical energy fluxes that drive the shocks. Modern HED facilities can produce such shocks, which are also present in dense, energetic, astrophysical systems such as supernovae. These shocks are also excellent targets for advanced simulations due to their range of spatial scales and complex radiation transport. Our second example will be relativistic plasmas. In general, these vary from plasmas containing relativistic particle beams, produced for some decades in the laboratory, to the relativistic thermal plasmas present for example in pulsar winds. Laboratory HED relativistic plasmas to date have been those produced by laser beams of irradiance ˜ 10^18 to 10^22 W/cm^2 or by accelerator-produced HED electron beams. These have applications ranging from generation of intense x-rays to production of proton beams for radiation therapy to acceleration of electrons. Here we will focus on electron acceleration, a spectacular recent success and a rare

New apparatus with high radiation energy between 320-460 nm: physical description and dermatological applications

International Nuclear Information System (INIS)

Mutzhas, M.F.; Holzle, E.; Hofmann, C.; Plewig, G.

1981-01-01

A new apparatus (UVASUN 5000) is presented with high-radiation energy between 320 to 460 nm. The measureable energy below 320 nm was shown to be many orders of magnitude too low to produce erythema. The radiator is a specially developed source for high uv-A intensity, housing a quartz bulb with a mixture of argon, mercury and metal-halides. At a skin-target distance of 0.2 m the size of the irradiated area is 0.35 x 0.35 m, and the measured mean uv-A intensity is about 1400 W. m-2 (140 mW . cm-2). The uv-A energy in the range of 320 to 400 nm is about 84% of the total radiation energy. Effects of very high doses of uv-A on human skin were studied. Following single uv-a applications the minimal tanning dose uv-A (MTD) and the immediate pigment darkening (IPD) dose of uv-A were established. The calculated IPD threshold time was 1.8 min at 0.2 m. Repeated exposure to this uv-A delivering system yields long lasting dark brown skin pigmentation without any clinical or histological signs of sunburn (uv-B) damage, epidermal hyperplasia or thickening of the stratum corneum. The instrument was also successfully used for photo-patch testing and reproduction of skin lesions of polymorphous light eruption. Minimal therapeutic results were seen in the phototherapy of vitiligo and inflammatory acne

Ferrites based infrared radiation coatings with high emissivity and high thermal shock resistance and their application on energy-saving kettle

International Nuclear Information System (INIS)

Zhang, Jianyi; Fan, Xi’an; Lu, Lei; Hu, Xiaoming; Li, Guangqiang

2015-01-01

Highlights: • The ferrites based infrared radiation coating was prepared by HVOF for the first time. • The infrared radiation coatings were applied firstly on the household kettle. • The bonding strength between the coating and substrate could reach 30.7 MPa. • The coating kept intact when cycle reached 27 by quenching from 1000 °C using water. • The energy-saving efficiency of the kettle with coating could reach 30.5%. - Abstract: Starting from Fe 2 O 3 , MnO 2 , Co 2 O 3 and NiO powders, the ferrites based infrared radiation coatings with high emissivity and high thermal shock resistance were successfully prepared on the surface of carbon steel by high velocity oxy-fuel spraying (HVOF). The coating thickness was about 120–150 μm and presented a typical flat lamellar structure. The coating surface was rough and some submicron grade grains distributed on it. The infrared emissivity of the ferrites based coating by HVOF was over 0.74 in 3–20 μm waveband at 800 °C, which was obviously higher than that of the coating by brushing process in the short waveband. The bonding strength was 30.7 MPa between the coating and substrate, which was five times more than that of conventional coatings by brushing process. The combined effect of the superior bonding strength, typical lamellar structure, pre-existing microcracks and newly generated pores made the cycle times reach 27 when the coating samples were quenched from 1000 °C using water. Lastly, the infrared radiation coatings were applied on the underside of household kettle, and the energy-saving efficiency could reach 30.5%. The ferrites based infrared radiation coatings obtained in this work are good candidates for saving energy in the field of cookware and industrial high temperature furnace