Application of an ultraminiature thermal neutron monitor for irradiation field study of accelerator-based neutron capture therapy
Phantom experiments to evaluate thermal neutron flux distribution were performed using the Scintillator with Optical Fiber (SOF) detector, which was developed as a thermal neutron monitor during boron neutron capture therapy (BNCT) irradiation. Compared with the gold wire activation method and Monte Carlo N-particle (MCNP) calculations, it was confirmed that the SOF detector is capable of measuring thermal neutron flux as low as 105 n/cm2/s with sufficient accuracy. The SOF detector will be useful for phantom experiments with BNCT neutron fields from low-current accelerator-based neutron sources. (Source: Journal of Radiation Research)
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Ishikawa, M., Tanaka, K., Endo, S., Hoshi, M. Tags: Physics Source Type: research
Estimation of relative biological effectiveness for boron neutron capture therapy using the PHITS code coupled with a microdosimetric kinetic model
The absorbed doses deposited by boron neutron capture therapy (BNCT) can be categorized into four components: α and 7Li particles from the 10B(n, α)7Li reaction, 0.54-MeV protons from the 14N(n, p)14C reaction, the recoiled protons from the 1H(n, n) 1H reaction, and photons from the neutron beam and 1H(n, )2H reaction. For evaluating the irradiation effect in tumors and the surrounding normal tissues in BNCT, it is of great importance to estimate the relative biological effectiveness (RBE) for each dose component in the same framework. We have, therefore, established a new method for estimating the RBE of all B...
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Horiguchi, H., Sato, T., Kumada, H., Yamamoto, T., Sakae, T. Tags: Physics Source Type: research
Development of a wavelength-separated type scintillator with optical fiber (SOF) dosimeter to compensate for the Cerenkov radiation effect
The scintillator with optical fiber (SOF) dosimeter consists of a miniature scintillator mounted on the tip of an optical fiber. The scintillator of the current SOF dosimeter is a 1-mm diameter hemisphere. For a scintillation dosimeter coupled with an optical fiber, measurement accuracy is influenced by signals due to Cerenkov radiation in the optical fiber. We have implemented a spectral filtering technique for compensating for the Cerenkov radiation effect specifically for our plastic scintillator-based dosimeter, using a wavelength-separated counting method. A dichroic mirror was used for separating input light signals....
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Ishikawa, M., Nagase, N., Matsuura, T., Hiratsuka, J., Suzuki, R., Miyamoto, N., Sutherland, K. L., Fujita, K., Shirato, H. Tags: Physics Source Type: research
A comparison of the dose distributions between the brachytherapy 125I source models, STM1251 and Oncoseed 6711, in a geometry lacking radiation equilibrium scatter conditions
The purpose of this study was to estimate the uncertainty in the dose distribution for the 125I source STM1251, as measured with a radiophotoluminescent glass rod dosimeter and calculated using the Monte Carlo code EGS5 in geometry that included the source structure reported by Kirov et al. This was performed at a range of positions in and on a water phantom 18 cm in diameter and 16 cm in length. Some dosimetry positions were so close to the surface that the backscatter margin was insufficient for photons. Consequently, the combined standard uncertainty (CSU) at the coverage factor k of 1 was 11.0–11.2% for the measu...
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Tanaka, K., Kamo, K.-i., Tateoka, K., Asanuma, O., Sato, K., Takeda, H., Sakata, K.-i., Takada, J. Tags: Physics Source Type: research
Co-visualization of DNA damage and ion traversals in live mammalian cells using a fluorescent nuclear track detector
We present a novel approach that uses a fluorescent nuclear track detector (FNTD) for the simultaneous detection of the geometrical images of ion traversals and DNA damage in single cells using confocal microscopy. HT1080 or HT1080–53BP1-GFP cells were cultured on the surface of a FNTD and exposed to 5.1-MeV/n neon ions. The positions of the ion traversals were obtained as fluorescent images of a FNTD. Localized DNA damage in cells was identified as fluorescent spots of -H2AX or 53BP1-GFP. These track images and images of damaged DNA were obtained in a short time using a confocal laser scanning microscope. The geomet...
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Kodaira, S., Konishi, T., Kobayashi, A., Maeda, T., Ahmad, T. A. F. T., Yang, G., Akselrod, M. S., Furusawa, Y., Uchihori, Y. Tags: Short Communication Source Type: research
Assessment of transposed ovarian movement: how much of a safety margin should be added during pelvic radiotherapy?
The purpose of this study was to analyze transposed ovarian movement. Data from 27 patients who underwent ovarian transposition after surgical treatment for uterine cancer were retrospectively analyzed. Computed tomography (CT) images including transposed ovaries were superimposed on other CT images acquired at different times, and were matched on bony structures. Differences in ovarian position between the CT images were measured. The planning organ at risk volume (PRV) margins were calculated from the formula of the 90% reference intervals (RIs) and the 95% RI, which were defined as mean ± 1.65 standard deviation ...
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Soda, I., Ishiyama, H., Ono, S., Takenaka, K., Arai, M., Arai, T., Iwase, H., Sekiguchi, A., Kawakami, S., Komori, S., Onda, T., Hayakawa, K. Tags: Oncology Source Type: research
Definitive radiotherapy for primary vaginal cancer: correlation between treatment patterns and recurrence rate
In conclusion, our treatment outcomes for vaginal cancer were acceptable, but external beam radiotherapy with brachytherapy (interstitial or intracavitary) was needed regardless of FIGO stage. Improvement of treatment outcomes in cases of FIGO Stage III or IV remains a significant challenge. (Source: Journal of Radiation Research)
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Kanayama, N., Isohashi, F., Yoshioka, Y., Baek, S., Chatani, M., Kotsuma, T., Tanaka, E., Yoshida, K., Seo, Y., Suzuki, O., Mabuchi, S., Shiki, Y., Tatsumi, K., Kimura, T., Teshima, T., Ogawa, K. Tags: Oncology Source Type: research
Dose-volume histogram comparison between static 5-field IMRT with 18-MV X-rays and helical tomotherapy with 6-MV X-rays
We treated prostate cancer patients with static 5-field intensity-modulated radiation therapy (IMRT) using linac 18-MV X-rays or tomotherapy with 6-MV X-rays. As X-ray energies differ, we hypothesized that 18-MV photon IMRT may be better for large patients and tomotherapy may be more suitable for small patients. Thus, we compared dose–volume parameters for the planning target volume (PTV) and organs at risk (OARs) in 59 patients with T1–3 N0M0 prostate cancer who had been treated using 5-field IMRT. For these same patients, tomotherapy plans were also prepared for comparison. In addition, plans of 18 patients w...
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Hayashi, A., Shibamoto, Y., Hattori, Y., Tamura, T., Iwabuchi, M., Otsuka, S., Sugie, C., Yanagi, T. Tags: Oncology Source Type: research
Differences in rates of radiation-induced true and false rib fractures after stereotactic body radiation therapy for Stage I primary lung cancer
The purpose of this study was to analyze the dosimetry and investigate the clinical outcomes of radiation-induced rib fractures (RIRFs) after stereotactic body radiotherapy (SBRT). A total of 126 patients with Stage I primary lung cancer treated with SBRT, who had undergone follow-up computed tomography (CT) at least 12 months after SBRT and who had no previous overlapping radiation exposure were included in the study. We used the Mantel–Haenszel method and multiple logistic regression analysis to compare risk factors. We analyzed D(0.5 cm3) (minimum absolute dose received by a 0.5-cm3 volume) and identified each rib...
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Miura, H., Inoue, T., Shiomi, H., Oh, R.-J. Tags: Oncology Source Type: research
The role of radiotherapy in the treatment of hepatocellular carcinoma with portal vein tumor thrombus
The aim of this study was to evaluate the role of radiotherapy in the treatment of hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVT) and to determine the prognostic factors for overall survival. Altogether, 106 patients with HCC and PVT referred for radiotherapy between 2004 and 2009 were retrospectively reviewed. A total of 60 Gy in 30 daily fractions was delivered with intensity-modulated radiotherapy techniques. Patient-related and treatment-related factors were analyzed to evaluate their prognostic significance for the overall survival rate. Complete response was noted in 10 patients and partial re...
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Yeh, S.-A., Chen, Y.-S., Perng, D.-S. Tags: Oncology Source Type: research
Clinical experience of volumetric modulated arc therapy for malignant pleural mesothelioma after extrapleural pneumonectomy
The purpose of this study was to evaluate the efficacy and safety of volumetric modulated arc therapy (VMAT) after extrapleural pneumonectomy (EPP) in patients with malignant pleural mesothelioma (MPM). A total of 15 patients who received VMAT after EPP were enrolled. All patients were males, and the median age was 67 years (Stage IB in two, II in six, and III in seven patients). The clinical target volume (CTV) included the entire preoperative ipsilateral hemithorax and involved nodal stations. The CTV was generally expanded by 10–15 mm beyond the planning target volume (PTV). The dose prescription was designed to c...
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Kimura, T., Doi, Y., Nakashima, T., Imano, N., Katsuta, T., Takahashi, S., Kenjo, M., Ozawa, S., Murakami, Y., Nagata, Y. Tags: Oncology Source Type: research
Efficacy and safety of nedaplatin-based concurrent chemoradiotherapy for FIGO Stage IB2-IVA cervical cancer and its clinical prognostic factors
Cisplatin-based concurrent chemoradiotherapy (CCRT) is a standard treatment for cervical cancer, but nedaplatin-based CCRT is not routinely administered. We evaluated the efficacy and safety of nedaplatin-based CCRT (35 mg/m2 weekly) and analyzed prognostic factors for survival among 52 patients with International Federation of Gynecology and Obstetrics (FIGO) Stage IB2–IVA cervical cancer treated from 1999 to 2009. Patients were treated with a combination of external beam radiotherapy of 40–56 Gy (in 20–28 fractions) and 13.6–28.8 Gy (in 2–4 fractions) of high-dose-rate (HDR) intracavitary br...
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Fujiwara, M., Isohashi, F., Mabuchi, S., Yoshioka, Y., Seo, Y., Suzuki, O., Sumida, I., Hayashi, K., Kimura, T., Ogawa, K. Tags: Oncology Source Type: research
Effects of X-ray and carbon ion beam irradiation on membrane permeability and integrity in Saccharomyces cerevisiae cells
Saccharomyces cerevisiae has served as a eukaryotic model in radiation biology studies of cellular responses to ionizing radiation (IR). Research in this field has thus far mainly been focused on DNA strand breaks, DNA base damage, or inhibition of protein activity. However, the effects of IR on S. cerevisiae cell membranes have barely been studied. Here, we investigated the changes in the permeability and integrity of S. cerevisiae cell membranes induced by high–linear energy transfer carbon ion (CI) beam or low–linear energy transfer X-ray. After CI exposure, protein elution and nucleotide diffusion were more...
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Cao, G., Zhang, M., Miao, J., Li, W., Wang, J., Lu, D., Xia, J. Tags: Biology Source Type: research
Sam68 is cleaved by caspases under apoptotic cell death induced by ionizing radiation
In this study, we found that Sam68 protein is cleaved in immune cells undergoing apoptosis induced by -radiation. Moreover, we found that Sam68 cleavage was induced by apoptotic stimuli containing -radiation in a caspase-dependent manner. In particular, we showed that activated casepase-3, 7, 8 and 9 can directly cleave Sam68 protein through in vitro protease cleavage assay. Finally, we found that the knockdown of Sam68 attenuated -radiation–induced cell death and growth suppression. Conclusively, the cleavage of Sam68 is a new indicator for the cell damaging effects of ionizing radiation. (Source: Journal of Radiation Research)
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Cho, S.-J., Choi, M. H., Nam, S. Y., Kim, J. Y., Kim, C. S., Pyo, S., Yang, K. H. Tags: Biology Source Type: research
Radioprotector WR-2721 and mitigating peptidoglycan synergistically promote mouse survival through the amelioration of intestinal and bone marrow damage
In this study, we evaluated the therapeutic impact of single agent or combination treatments with 2-(3-aminopropylamino) ethylsulphanyl phosphonic acid (WR-2721) and peptidoglycan (PGN, a toll-like receptor 2 (TLR-2) agonist) on radiation-induced injury of the intestine and bone marrow in lethally irradiated male C57BL/6 mice. A dose of 3 mg of WR-2721 per mouse (167 mg/kg, intraperitoneally) was given 30 min before irradiation, and 30 μg of PGN per mouse (1.7 mg/kg) was injected intraperitoneally 24 h after 10 Gy irradiation. Bone marrow cluster of differentiation (CD)45+ and CD34+ markers of multiple haematopoietic li...
Source: Journal of Radiation Research - March 13, 2015 Category: Physics Authors: Liu, W., Chen, Q., Wu, S., Xia, X., Wu, A., Cui, F., Gu, Y.-p., Zhang, X., Cao, J. Tags: Biology Source Type: research
