Proton Therapy in Japan

Abstract

There are two facilities for clinical trials with protons in Japan: the National Institute of Radiological Sciences (NIRS), Chiba, and the Particle Radiation Medical Science Center (PARMS), University of Tsukuba. At the National Institute of Radiological Sciences, patient treatment with the 70 MeV proton beam began in November 1979, and 29 patients were treated through December 1984. Of 11 patients who received protons only, 9 have had local control of the tumor. Two of the 9 patients, suffering from recurrent tumor after radical photon beam irradiation, developed complications after proton treatment. In the patients treated with photons or neutrons followed by proton boost, tumors were controlled in 12 of 18 patients (66.6%), and no complications were observed in this series. Malignant melanoma could not be controlled with the proton beam. A spot-beam-scanning system for protons has been effectively used in the clinical trials to minimize the dose to the normal tissues and to concentrate the dose in the target volume. At the Particle Radiation Medical Science Center, University of Tsukuba, treatment with a vertical 250 MeV proton beam was begun in April 1983, and 22 patients were treated through February 1984. Local control of the tumor was observed in 14 of 22 patients (63.6%), whereas there was no local control in the treatment of glioblastoma multiforme. There have been no severe complications in patients treated at PARMS. The results suggest that local control of tumors will be better with proton beams than with photon beams, whereas additional modalities are required to manage radioresistant tumors.

Reducing stray radiation dose to patients receiving passively scattered proton radiotherapy for prostate cancer

“…A passively scattered nozzle at the Proton Medical Research Center at the University of Tsukuba (Japan) uses a brass multi-leaf collimator to remove non-therapeutic protons from the beam. The spot-beam-scanning system at the National Institute of Radiological Sciences in Chiba, Japan uses a backup multi-rod collimator made of brass (Tsunemoto et al 1985). Reinforcing the idea of incorporating a variable multi-leaf collimator in nozzle design is the work by Tayama et al (2006), who investigated the effect of changing the aperture size of a pre-collimator on dose equivalent from stray neutrons emanating from the nozzle.…”

Nuclear physics in particle therapy: a review

“…The clinical implications of beam scanning were analyzed in the late 1970s and early 1980s (Grunder andLeemann 1977, Goitein andChen 1983). Spot scanning, where the beam spots are delivered one by one with beam off time in between, covering the target volume without an aperture, was first introduced at NIRS using a 70 MeV proton beam (Tsunemoto et al 1985). Pencil beam scanning was implemented in carbon ion therapy for the first time at GSI (Haberer et al 1993) and is now also a standard in all heavy ion centers in Europe and China.…”

Instrumentation for treatment of cancer using proton and light-ion beams

“…121 •Very active proton therapy programs are in progress in Japan. 122 Between 1979 and 1991 the National Institute of Radiological Sciences (NIRS) in Chiba has treated 75 patients using 70-MeV ( 11 ) protons (to be upgraded to 90 Me V). 123 In 1983 a clinical study of proton radiotherapy was initiated at the Particle Radiation Medical Science Center (PARMS) of the University of Tsukuba, Japan using the 250-MeV protons obtained by degrading the 500-MeV protons from the booster synchrotron of the High Energy Physics Laboratory (KEK).…”