Neutron relative biological effectiveness in Hiroshima and Nagasaki atomic bomb survivors: a critical review
The calculated risk of cancer in humans due to radiation exposure is based primarily on long-term follow-up studies, e.g. the life-span study (LSS) on atomic bomb (A-bomb) survivors in Hiroshima and Nagasaki. Since A-bomb radiation consists of a mixture of -rays and neutrons, it is essential that the relative biological effectiveness (RBE) of neutrons is adequately evaluated if a study is to serve as a reference for cancer risk. However, the relatively small neutron component hampered the direct estimation of RBE in LSS data. To circumvent this problem, several strategies have been attempted, including dose-independent con...
Source: Journal of Radiation Research - December 2, 2016 Category: Physics Authors: Sasaki, M. S., Endo, S., Hoshi, M., Nomura, T. Tags: Review Source Type: research
Carbon-ion pencil beam scanning for thoracic treatment - initiation report and dose metrics evaluation
In conclusion, scanned beam CIRT provided treatments equivalent to passive scattering CIRT for thoracic tumors. Increased sample numbers and longer-term observation are needed. (Source: Journal of Radiation Research)
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Karube, M., Mori, S., Tsuji, H., Yamamoto, N., Nakajima, M., Nakagawa, K., Kamada, T. Tags: Technical report Source Type: research
PU-H71, a novel Hsp90 inhibitor, as a potential cancer-specific sensitizer to carbon-ion beam therapy
PU-H71, a heat shock protein 90 (Hsp90) inhibitor, has yielded therapeutic efficacy in many preclinical models and is currently in clinical trials. Carbon-ion radiotherapy (CIRT) has provided successful tumor control; however, there is still room for improvement, particularly in terms of tumor-specific radiosensitization. The Hsp90 inhibitor PU-H71 has been shown to sensitize tumor cells to X-ray radiation. A murine osteosarcoma cell line (LM8) and a normal human fibroblast cell line (AG01522) were treated with PU-H71 before X-ray, 14- or 50-keV/µm carbon-ion beam (C-ion) irradiation. Cell survival and protein expres...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Li, H. K., Matsumoto, Y., Furusawa, Y., Kamada, T. Tags: Short communication Source Type: research
A novel Nrf2 activator from microbial transformation inhibits radiation-induced dermatitis in mice
Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcriptional factor that regulates many antioxidants, and we have recently succeeded in obtaining a novel Nrf2 activator, RS9, from microbial transformation. RS9 is categorized as a triterpenoid, and well-known triterpenoids such as RTA 402 (bardoxolone methyl) and RTA 408 have been tested in clinical trials. RTA 408 lotion is currently being tested in patients at risk for radiation dermatitis. This prompted us to study the profiles of RS9 in the skin. All the above triterpenoids increased the level of an Nrf2-targeted gene, NADPH:quinone oxidoreductase-1, in norma...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Nakagami, Y., Masuda, K. Tags: Short communication Source Type: research
The impact of emphysema on dosimetric parameters for stereotactic body radiotherapy of the lung
The purpose of this study was to evaluate the impact of emphysematous changes in lung on dosimetric parameters in stereotactic body radiation therapy (SBRT) for lung tumor. A total of 72 treatment plans were reviewed, and dosimetric factors [including homogeneity index (HI) and conformity index (CI)] were evaluated. Emphysematous changes in lung were observed in 43 patients (60%). Patients were divided into three groups according to the severity of emphysema: no emphysema (n = 29), mild emphysema (n = 22) and moderate to severe emphysema groups (n = 21). The HI (P < 0.001) and the CI (P = 0.029) were significantly diffe...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Ochiai, S., Nomoto, Y., Yamashita, Y., Inoue, T., Murashima, S., Hasegawa, D., Kurita, Y., Watanabe, Y., Toyomasu, Y., Kawamura, T., Takada, A., Ii, N., Kobayashi, S., Sakuma, H. Tags: Regular paper Source Type: research
Dosimetric comparison of carbon ion and X-ray radiotherapy for Stage IIIA non-small cell lung cancer
The present study compared the dose–volume histograms of patients with Stage IIIA non–small cell lung cancer (NSCLC) treated with carbon ion radiotherapy with those of patients treated with X-ray radiotherapy. Patients with Stage IIIA NSCLC (n = 10 patients for each approach) were enrolled. Both radiotherapy plans were calculated with the same targets and organs at risk on the same CT. The treatment plan for the prophylactic lymph node and primary tumor (PTV1) delivered 40 Gy for X-ray radiotherapy and 40 Gy (relative biological effectiveness; RBE) for carbon ion radiotherapy. The total doses for the ...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Kubo, N., Saitoh, J.-i., Shimada, H., Shirai, K., Kawamura, H., Ohno, T., Nakano, T. Tags: Regular paper Source Type: research
Radiation therapy for nasopharyngeal carcinoma: the predictive value of interim survival assessment
Pretreatment characteristics are suggested as predictive and/or prognostic factors for nasopharyngeal carcinoma (NPC); however, individual tumor radiosensitivities have previously not been considered. As boost planning is recommended for NPC, we performed interim assessments of magnetic resonance (MR) images for boost planning and retrospectively evaluated their predictive value for the survival of NPC patients. Radiation therapy via elective nodal irradiation (median dose: 39.6 Gy) with/without chemotherapy was used to treat 63 NPC patients. Boost irradiation (median total dose: 70 Gy) was performed based on the interim a...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Toya, R., Murakami, R., Saito, T., Murakami, D., Matsuyama, T., Baba, Y., Nishimura, R., Hirai, T., Semba, A., Yumoto, E., Yamashita, Y., Oya, N. Tags: Regular Paper Source Type: research
Impact of pretreatment whole-tumor perfusion computed tomography and 18F-fluorodeoxyglucose positron emission tomography/computed tomography measurements on local control of non-small cell lung cancer treated with stereotactic body radiotherapy
This study aimed to investigate the correlation between the average iodine density (AID) detected by dual-energy computed tomography (DE-CT) and the maximum standardized uptake value (SUVmax) yielded by [18F] fluorodeoxyglucose positron emission tomography (18F-FDG PET) for non–small cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT). Seventy-four patients with medically inoperable NSCLC who underwent both DE-CT and 18F-FDG PET/CT before SBRT (50-60 Gy in 5-6 fractions) were followed up after a median interval of 24.5 months. Kaplan–Meier analysis was used to determine associations betw...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Aoki, M., Akimoto, H., Sato, M., Hirose, K., Kawaguchi, H., Hatayama, Y., Seino, H., Kakehata, S., Tsushima, F., Fujita, H., Fujita, T., Fujioka, I., Tanaka, M., Miura, H., Ono, S., Takai, Y. Tags: Regular paper Source Type: research
Whole-pelvic radiotherapy with spot-scanning proton beams for uterine cervical cancer: a planning study
The aim of this study was to compare the dosimetric parameters of whole-pelvic radiotherapy (WPRT) for cervical cancer among plans involving 3D conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), or spot-scanning proton therapy (SSPT). The dose distributions of 3D-CRT-, IMRT-, and SSPT-based WPRT plans were compared in 10 patients with cervical cancer. All of the patients were treated with a prescribed dose of 50.4 Gy in 1.8-Gy daily fractions, and all of the plans involved the same planning target volume (PTV) constrictions. A 3D-CRT plan involving a four-field box, an IMRT plan involving seven copla...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Hashimoto, S., Shibamoto, Y., Iwata, H., Ogino, H., Shibata, H., Toshito, T., Sugie, C., Mizoe, J.-e. Tags: Regular paper Source Type: research
Efficacy of stereotactic body radiotherapy for hepatocellular carcinoma with portal vein tumor thrombosis/inferior vena cava tumor thrombosis: evaluation by comparison with conventional three-dimensional conformal radiotherapy
This study aimed to evaluate the efficacy of stereotactic body radiotherapy (SBRT) compared with three-dimensional conformal radiotherapy (3DCRT). Forty-three patients with portal vein tumor thrombosis (PVTT)/inferior vena cava tumor thrombosis (IVCTT) treated with SBRT (27 with CyberKnife (CK) and 16 with TrueBeam (TB)) from April 2013 to December 2014, and 54 treated with 3DCRT from June 2008 to March 2013 were evaluated. Dosimetric parameters, response to radiotherapy (RT) and survival outcomes were compared in total SBRT vs. 3DCRT, CK vs. 3DCRT and TB vs. 3DCRT, respectively. The median biologically effective dose 10 (...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Matsuo, Y., Yoshida, K., Nishimura, H., Ejima, Y., Miyawaki, D., Uezono, H., Ishihara, T., Mayahara, H., Fukumoto, T., Ku, Y., Yamaguchi, M., Sugimoto, K., Sasaki, R. Tags: Regular Paper Source Type: research
Protective effects of ulinastatin and methylprednisolone against radiation-induced lung injury in mice
The effectiveness of ulinastatin and methylprednisolone in treating pathological changes in mice with radiation-induced lung injury (RILI) was evaluated. Forty C57BL/6 female mice received whole-chest radiation (1.5 Gy/min for 12 min) and were randomly allocated into Group R (single radiation, n = 10), Group U (ulinastatin treatment, n = 10), Group M (methylprednisolone treatment, n = 10), or Group UM (ulinastatin and methylprednisolone treatment, n = 10). Another 10 untreated mice served as controls (Group C). Pathological changes in lung tissue, pulmonary interstitial area density ...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Sun, Y., Du, Y.-J., Zhao, H., Zhang, G.-X., Sun, N., Li, X.-J. Tags: Regular Paper Source Type: research
Consecutive CT-guided core needle tissue biopsy of lung lesions in the same dog at different phases of radiation-induced lung injury
This project aimed to set up a Beagle dog model of radiation-induced lung injury in order to supply fresh lung tissue samples in the different injury phases for gene and protein research. Three dogs received 18 Gy X-ray irradiation in one fraction, another three dogs received 8 Gy in each of three fractions at weekly intervals, and one control dog was not irradiated. Acute pneumonitis was observed during the first 3 months after radiation, and chronic lung fibrosis was found during the next 4–12 months in all the dogs exposed to radiation. CT-guided core needle lung lesion biopsies were extracted from each dog five t...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Yin, Z., Deng, S., Liang, Z., Wang, Q. Tags: Regular paper Source Type: research
A calibration method for realistic neutron dosimetry in radiobiological experiments assisted by MCNP simulation
Many studies on biological effects of neutrons involve dose responses of neutrons, which rely on accurately determined absorbed doses in the irradiated cells or living organisms. Absorbed doses are difficult to measure, and are commonly surrogated with doses measured using separate detectors. The present work describes the determination of doses absorbed in the cell layer underneath a medium column (DA) and the doses absorbed in an ionization chamber (DE) from neutrons through computer simulations using the MCNP-5 code, and the subsequent determination of the conversion coefficients R (= DA/DE). It was found that R in...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Shahmohammadi Beni, M., Krstic, D., Nikezic, D., Yu, K. N. Tags: Regular paper Source Type: research
Changes in the distribution and function of leukocytes after whole-body iron ion irradiation
This study evaluated C57BL/6 mice on Day 40 after total-body 56Fe26+ irradiation at 0, 1, 2 and 3 gray (Gy). Radiation consistently increased thymus mass (one-way ANOVA: P < 0.005); spleen, liver and lung masses were similar among all groups. In the blood, there was no radiation effect on the white blood cell (WBC) count or major leukocyte types. However, the red blood cell count, hemoglobin, hematocrit and the CD8+ T cytotoxic (Tc) cell count and percentage all decreased, while both the CD4:CD8 (Th:Tc) cell ratio and spontaneous blastogenesis increased, in one or more irradiated groups compared with unirradia...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Gridley, D. S., Pecaut, M. J. Tags: Regular paper Source Type: research
Upregulation of microRNA-98 increases radiosensitivity in esophageal squamous cell carcinoma
In this study, we aimed to identify the miRNAs that are associated with radioresistance in ESCC. We used a miRNA microarray to perform a comparison of miRNA expression in both ESCC parental and acquired radioresistance cell lines. qRT-PCR was used to confirm the alterations. Cell radiosensitivity was determined with a survival fraction assay. Functional analyses of the identified miRNA in ESCC cells with regard to metastasis and apoptosis were performed by transwell assays and flow cytometry. The miRNA targets were identified with pathway analysis and confirmed with a luciferase assay. miR-98 was recognized as the most dow...
Source: Journal of Radiation Research - September 29, 2016 Category: Physics Authors: Jin, Y.-Y., Chen, Q.-J., Wei, Y., Wang, Y.-L., Wang, Z.-W., Xu, K., He, Y., Ma, H.-B. Tags: Regular paper Source Type: research
