Emerging issues in radiogenic cataracts and cardiovascular disease
In 2011, the International Commission on Radiological Protection issued a statement on tissue reactions (formerly termed non-stochastic or deterministic effects) to recommend lowering the threshold for cataracts and the occupational equivalent dose limit for the crystalline lens of the eye. Furthermore, this statement was the first to list circulatory disease (cardiovascular and cerebrovascular disease) as a health hazard of radiation exposure and to assign its threshold for the heart and brain. These changes have stimulated various discussions and may have impacts on some radiation workers, such as those in the medical se...
Source: Journal of Radiation Research - September 10, 2014 Category: Physics Authors: Hamada, N., Fujimichi, Y., Iwasaki, T., Fujii, N., Furuhashi, M., Kubo, E., Minamino, T., Nomura, T., Sato, H. Tags: Review Source Type: research
How to incorporate the dose-rate effect into evaluation of cancer risk for radiation protection
(Source: Journal of Radiation Research)
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Tatsumi, K., Tanooka, H. Tags: Meeting Report Source Type: research
Long-term epigenetic effects of exposure to low doses of 56Fe in the mouse lung
Despite significant progress, the long-term health effects of exposure to high charge (Z) and energy (E) nuclei (HZEs) and the underlying mechanisms remain poorly understood. Mouse studies show that space missions can result in pulmonary pathological states. The goal of this study was to evaluate the pro-fibrotic and pro-carcinogenic effects of exposure to low doses of heavy iron ions (56Fe) in the mouse lung. Exposure to 56Fe (600 MeV; 0.1, 0.2 and 0.4 Gy) resulted in minor pro-fibrotic changes, detected at the beginning of the fibrotic phase (22 weeks post exposure), which were exhibited as increased expression of chemok...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Nzabarushimana, E., Miousse, I. R., Shao, L., Chang, J., Allen, A. R., Turner, J., Stewart, B., Raber, J., Koturbash, I. Tags: Short Communications Source Type: research
Enhanced radiobiological effects at the distal end of a clinical proton beam: in vitro study
In the clinic, the relative biological effectiveness (RBE) value of 1.1 has usually been used in relation to the whole depth of the spread-out Bragg-peak (SOBP) of proton beams. The aim of this study was to confirm the actual biological effect in the SOBP at the very distal end of clinical proton beams using an in vitro cell system. A human salivary gland tumor cell line, HSG, was irradiated with clinical proton beams (accelerated by 190 MeV/u) and examined at different depths in the distal part and the center of the SOBP. Surviving fractions were analyzed with the colony formation assay. Cell survival curves and the survi...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Matsumoto, Y., Matsuura, T., Wada, M., Egashira, Y., Nishio, T., Furusawa, Y. Tags: Short Communications Source Type: research
Relative biological effectiveness of therapeutic proton beams for HSG cells at Japanese proton therapy facilities
We investigated the relative biological effectiveness (RBE) of therapeutic proton beams at six proton facilities in Japan with respect to cell lethality of HSG cells. The RBE of treatments could be determined from experimental data. For this purpose, we used a cell survival assay to compare the cell-killing efficiency of proton beams. Among the five linear accelerator (LINAC) X-ray machines at 4 or 6 MeV that were used as reference beams, there was only a small variation (coefficient of variation CV = 3.1% at D10) in biological effectiveness. The averaged value of D10 for the proton beams at the middle position of the spre...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Aoki-Nakano, M., Furusawa, Y., Uzawa, A., Matsumoto, Y., Hirayama, R., Tsuruoka, C., Ogino, T., Nishio, T., Kagawa, K., Murakami, M., Kagiya, G., Kume, K., Hatashita, M., Fukuda, S., Yamamoto, K., Fuji, H., Murayama, S., Hata, M., Sakae, T., Matsumoto, H. Tags: Technology Source Type: research
Inflammation as well as angiogenesis may participate in the pathophysiology of brain radiation necrosis
Radiation necrosis (RN) after intensive radiation therapy is a serious problem. Using human RN specimens, we recently proved that leaky angiogenesis is a major cause of brain edema in RN. In the present study, we investigated the same specimens to speculate on inflammation's effect on the pathophysiology of RN. Surgical specimens of symptomatic RN in the brain were retrospectively reviewed by histological and immunohistochemical analyses using hematoxylin and eosin (H&E) staining as well as immunohistochemical staining for VEGF, HIF-1α, CXCL12, CXCR4, GFAP, CD68, hGLUT5, CD45, IL-1α, IL-6 TNF-α and NF...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Yoritsune, E., Furuse, M., Kuwabara, H., Miyata, T., Nonoguchi, N., Kawabata, S., Hayasaki, H., Kuroiwa, T., Ono, K., Shibayama, Y., Miyatake, S.-I. Tags: Oncology Source Type: research
Analysis of simultaneous modulated accelerated radiotherapy (SMART) for nasopharyngeal carcinomas
The purpose of this study was to analyze the clinical outcomes of simultaneous modulated accelerated radiotherapy (SMART) in patients with nasopharyngeal carcinoma (NPC). A total of 97 patients who underwent SMART for NPC between August 2005 and November 2011 were evaluated. The prescribed dose was 69.9 Gy/30 fractions at 2.33 Gy/fraction to the primary gross tumor volume (PGTV) including the nasopharynx gross target volume and the positive neck lymph nodes, and 60 Gy/30 fraction at 2.0 Gy/fraction to the PCTV1; 54 Gy/30 fractions at 1.8 Gy/fraction was given to the PCTV2. Among 59 patients with local advanced disease, 31 ...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Tang, J. M., Ma, X. M., Hou, Y. L., Dai, L. Y., Cao, H. B., Ye, M., Bai, Y. R. Tags: Oncology Source Type: research
Dose-volume histogram parameters of high-dose-rate brachytherapy for Stage I-II cervical cancer (
We investigated the rectal dose-sparing effect and tumor control of a point A dose-reduced plan in patients with Stage I–II cervical cancer (≤4 cm) arising from a small-sized uterus. Between October 2008 and August 2011, 19 patients with Stage I–II cervical cancer (≤4 cm) were treated with external beam radiotherapy (EBRT) for the pelvis and CT-guided brachytherapy. Seven patients were treated with brachytherapy with standard loading of source-dwell positions and a fraction dose of 6 Gy at point A (conventional brachy-plan). The other 12 patients with a small uterus close to the rectum or small intestine ...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Nakagawa, A., Ohno, T., Noda, S.-e., Kubo, N., Kuwako, K., Saitoh, J.-i., Nakano, T. Tags: Oncology Source Type: research
Dose error from deviation of dwell time and source position for high dose-rate 192Ir in remote afterloading system
The influence of deviations in dwell times and source positions for 192Ir HDR-RALS was investigated. The potential dose errors for various kinds of brachytherapy procedures were evaluated. The deviations of dwell time T of a 192Ir HDR source for the various dwell times were measured with a well-type ionization chamber. The deviations of source position P were measured with two methods. One is to measure actual source position using a check ruler device. The other is to analyze peak distances from radiographic film irradiated with 20 mm gap between the dwell positions. The composite dose errors were calculated using Gaussia...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Okamoto, H., Aikawa, A., Wakita, A., Yoshio, K., Murakami, N., Nakamura, S., Hamada, M., Abe, Y., Itami, J. Tags: Oncology Source Type: research
Utility of Smart Arc CDR for intensity-modulated radiation therapy for prostate cancer
The objective of this study was to clarify the utility of CDR mode for prostate IMRT. Pinnacle3 and Clinac 21EX linac (Varian, 10 MV X-rays) were used for planning. The plans were created for 28 patients using a fixed multi-field IMRT (f-IMRT), VMAT and CDR techniques. The dose distribution results were classified into three groups: optimal, suboptimal and reject. For the f-IMRT, VMAT and CDR results, 25, 26 and 21 patients were classified as ‘optimal’, respectively. Our results show a significant reduction in the achievement rate of ‘optimal’ for a CDR when the bladder volume is <100 cm3. The to...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Hatanaka, S., Tamaki, S., Endo, H., Mizuno, N., Nakamura, N. Tags: Oncology Source Type: research
Determination of the optimal method for the field-in-field technique in breast tangential radiotherapy
Several studies have reported the usefulness of the field-in-field (FIF) technique in breast radiotherapy. However, the methods for the FIF technique used in these studies vary. These methods were classified into three categories. We simulated a radiotherapy plan with each method and analyzed the outcomes. In the first method, a pair of subfields was added to each main field: the single pair of subfields method (SSM). In the second method, three pairs of subfields were added to each main field: the multiple pairs of subfields method (MSM). In the third method, subfields were alternately added: the alternate subfields metho...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Tanaka, H., Hayashi, S., Hoshi, H. Tags: Oncology Source Type: research
The clinical outcome of intracranial hemangioblastomas treated with linac-based stereotactic radiosurgery and radiotherapy
The objective of this study was to analyze the clinical results of 14 patients with 56 intracranial hemangioblastomas treated with linear accelerator (linac)-based stereotactic radiosurgery (SRS) and radiotherapy (SRT) in the same institute. The median age of patients was 41 years (range, 28–73 years). Nine of the patients (64%) had von Hippel-Lindau disease. A total of 39 lesions (70%) were treated with CyberKnife (CK), and 17 lesions (30%) were treated with X-Knife. The median pretreatment volume was 0.26 cm3 (range, 0.026–20.4 cm3). The median marginal dose was 20 Gy (range, 10–32 Gy) in 1 fraction (ra...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Puataweepong, P., Dhanachai, M., Hansasuta, A., Dangprasert, S., Sitathanee, C., Puddhikarant, P., Jiarpinitnun, C., Ruangkanchanasetr, R., Dechsupa, P., Pairat, K. Tags: Oncology Source Type: research
Correlation between target volume and electron transport effects affecting heterogeneity corrections in stereotactic body radiotherapy for lung cancer
In this study, the correlation between the planning target volume (PTV) and the dose delivery is investigated by separation of the heterogeneity correction effects into photon attenuation and electron transport. Under Institutional Review Board exemption status, 74 patients with lung cancer who were treated with SBRT were retrospectively evaluated. All treatment plans were generated using an anisotropic analytical algorithm (AAA) of an Eclipse (Varian Medical Systems, Palo Alto, CA) treatment planning system. Two additional plans were created using the same treatment parameters (monitor units, beam angles and energy): a pl...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Akino, Y., Das, I. J., Cardenes, H. R., Desrosiers, C. M. Tags: Oncology Source Type: research
Radiation therapy for carcinoma of the uterine cervix: comparison of two brachytherapy schedules
We compared the survival rates and late effects for two groups of cervical cancer patients treated with almost the same external radiotherapy but different remote afterloading systems (RALS) for high-dose-rate intracavitary radiation therapy regimens. A total of 218 patients with carcinoma of the uterine cervix were treated. For 98 patients, intracavitary brachytherapy was delivered with 6–7.5 Gy/fraction to Point A (Group A), and for 120, 5 Gy/fraction with a modified source step size (Group B). The 3-year cause-specific survival rates by stage and treatment schedule were Group A: 91% and Group B: 96% in Stage I, 89...
Source: Journal of Radiation Research - July 15, 2014 Category: Physics Authors: Chatani, M., Tsuboi, K., Yagi, M., Fujiwara, K., Tachimoto, R. Tags: Oncology Source Type: research
