Hiroki Shirato

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PURPOSE To determine how the omission of whole brain radiotherapy (WBRT) affects the neurocognitive function of patients with one to four brain metastases who have been treated with stereotactic radiosurgery (SRS). METHODS AND MATERIALS In a prospective randomized trial between WBRT+SRS and SRS alone for patients with one to four brain metastases, we(More)
PURPOSE In this work, three-dimensional (3D) motion of lung tumors during radiotherapy in real time was investigated. Understanding the behavior of tumor motion in lung tissue to model tumor movement is necessary for accurate (gated or breath-hold) radiotherapy or CT scanning. METHODS Twenty patients were included in this study. Before treatment, a 2-mm(More)
The Synchrony Respiratory Tracking System (RTS) is a treatment option of the CyberKnife robotic treatment device to irradiate extra-cranial tumors that move due to respiration. Advantages of RTS are that patients can breath normally and that there is no loss of linac duty cycle such as with gated therapy. Tracking is based on a measured correspondence model(More)
BACKGROUND Stereotactic irradiation (STI) has been actively performed using various methods to achieve better local control of Stage I nonsmall cell lung carcinoma (NSCLC) in Japan. The authors retrospectively evaluated results from a Japanese multiinstitutional study. METHODS Patients with Stage I NSCLC (n = 245; median age, 76 years; T1N0M0, n = 155;(More)
INTRODUCTION Hypofractionated stereotactic radiotherapy (HypoFXSRT) has recently been used for the treatment of small lung tumors. We retrospectively analyzed the treatment outcome of HypoFXSRT for stage I non-small cell lung cancer (NSCLC) treated in a Japanese multi-institutional study. METHODS This is a retrospective study to review 257 patients with(More)
Germ cell tumours (GCTs) of the central nervous system (CNS) encompass various histological subtypes, and their optimal management has been the subject of debate. To indicate a better management strategy for each subtype, we analysed the records of 111 patients (median age 14 years), who underwent treatment since 1970. With a median follow-up duration of 86(More)
We have shown that metastasis is suppressed by low-dose total-body irradiation (TBI) in tumor-bearing rats. We have evaluated the immunological effects of low-dose TBI. Total-body irradiation with 0.2 Gy was given 14 days after the implantation of 5 x 10(5) allogenic hepatoma cells (KDH-8) which produce transforming growth factor beta (TGF-beta). On day 21,(More)
PURPOSE To determine the role of radiotherapy in the management of spinal cord gliomas. METHODS AND MATERIALS Thirty-six patients with spinal cord glioma treated between 1979 and 1993 were examined. The patients had 13 astrocytic tumors (7 astrocytomas, 4 anaplastic astrocytomas, 2 glioblastomas), 22 ependymal tumors (18 ependymomas, 4 myxopapillary(More)
Image guidance in radiotherapy and extracranial radiosurgery offers the potential for precise radiation dose delivery to a moving tumour. Recent work has demonstrated how to locate and track the position of a tumour in real-time using diagnostic x-ray imaging to find implanted radio-opaque markers. However, the delivery of a treatment plan through gating or(More)
PURPOSE To examine the variability in the qualitative and quantitative results of computed tomographic (CT) perfusion imaging generated from identical source data of stroke patients by using commercially available software programs provided by various CT manufacturers. MATERIALS AND METHODS Institutional review board approval and informed consent were(More)