Shigeyuki Murayama

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PURPOSE Proton beam therapy (PBT) is theoretically an excellent modality for external beam radiotherapy, providing an ideal dose distribution. However, it is not clear whether PBT for prostate cancer can clinically control toxicities. The purpose of the present study was to estimate prospectively the incidence of late rectal toxicities after PBT for(More)
BACKGROUND AND PURPOSE To compare treatment planning methods in high-dose-rate (HDR) brachytherapy of prostate cancer. In particular, to assess quantitatively the dosimetric superiority, if any, of the anatomy-based dwell position (ABDP) and inverse optimization (IO) over the conventional cylindrical dwell position (CDP), geometric optimization (GO), and(More)
We explored the general feasibility of proton beam therapy for chordoma and chondrosarcoma of the skull base. Clinical records and treatment-planning data of patients with the pathological diagnosis of chordoma or chondrosarcoma were examined. Proton beam therapy was administered for gross tumor mass as well as microscopic residual disease after surgery.(More)
PURPOSE To evaluate dose-volume histogram (DVH) parameters as predictors of radiation pneumonitis (RP) in esophageal cancer patients treated with definitive concurrent chemoradiotherapy. PATIENTS AND METHODS Thirty-seven esophageal cancer patients treated with radiotherapy with concomitant chemotherapy consisting of 5-fluorouracil and cisplatin were(More)
PURPOSE The aim of this study was to investigate the frequency and characteristics of a docetaxel-induced radiation recall phenomenon. METHODS AND MATERIALS Past histories of radiotherapy and radiation recall phenomenon (RRP) were analyzed in 461 patients who were administered docetaxel at our hospital between September 2002 and November 2005. RESULTS(More)
Intensity-modulated proton therapy (IMPT) is expected to improve treatment results with fewer side effects than other proton therapies. The purpose of this study was to evaluate the tumor sites for which IMPT was effective under the same beam calculation conditions by planning IMPT for typical cases treated with passive scattering proton therapy (PSPT). We(More)
Recent progress in the treatment for pediatric malignancies using a combination of surgery, chemotherapy, and radiotherapy has improved survival. However, late toxicities of radiotherapy are a concern in long-term survivors. A recent study suggested reduced secondary cancer and other late toxicities after proton beam therapy (PBT) due to dosimetric(More)
PURPOSE The efficiency and precision of respiratory gated radiation therapy for tumors is affected by variations in respiration-induced tumor motion. We evaluated the use of individualized and population-based parameters for such treatment. METHODS AND MATERIALS External respiratory signal records and images of respiration-induced tumor motion were(More)
This study aimed to evaluate the efficacy and safety of reirradiation with intensity-modulated radiation therapy (IMRT) for spinal metastases. We retrospectively analyzed 23 patients with spinal metastases who underwent IMRT reirradiation between December 2006 and July 2013. We evaluated the spinal radiation doses during the first and second radiation(More)
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(More)