title: Proton beam therapy in Japan: current and future status.
abstract: The number of patients treated by proton beam therapy in Japan since 2000 has increased; in 2016, 11 proton facilities were available to treat patients. Notably, proton beam therapy is very useful for pediatric cancer; since the pediatric radiation dose to normal tissues should be reduced as much as possible because of the effect of radiation on growth, intellectual development, endocrine organ function and secondary cancer development. Hepatocellular carcinoma is common in Asia, and most of the studies of proton beam therapy for liver cancer have been reported by Japanese investigators. Proton beam therapy is also a standard treatment for nasal and paranasal lesions and lesions at the base of the skull, because the radiation dose to critical organs such as the eyes, optic nerves and central nervous system can be reduced with proton beam therapy. For prostate cancer, comparative studies that address adverse effects, safety, patient quality of life and socioeconomic issues should be performed to determine the appropriate use of proton beam therapy for prostate cancer. Regarding new proton beam therapy applications, experience with proton beam therapy combined with chemotherapy is limited, although favorable outcomes have been recently reported for locally advanced lung cancer, esophageal cancer and pancreatic cancer. Therefore, 'chemoproton' therapy appears to be a very attractive field for further clinical investigations. In conclusion, there are cost issues and considerations regarding national insurance for the use of proton beam therapy in Japan. Further studies and discussions are needed to address the use of proton beam therapy for several types of cancers, and for maintaining the quality of life of patients while retaining a high cure rate.
authors.affiliation: Department of Radiation Oncology and Proton Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki, Japan hsakurai@pmrc.tsukuba.ac.jp.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Sakurai
authors.affiliation: Department of Radiation Oncology and Proton Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ishikawa
authors.affiliation: Department of Radiation Oncology and Proton Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Okumura
mesh_terms: D002173:Cancer Care Facilities; D004938:Esophageal Neoplasms / Q000532:radiotherapy; D006801:Humans; D019458:Insurance Coverage; D007564:Japan; D008113:Liver Neoplasms / Q000473:pathology / Q000532:radiotherapy; D008297:Male; D009369:Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D009669:Nose Neoplasms / Q000532:radiotherapy; D010190:Pancreatic Neoplasms / Q000532:radiotherapy; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D061766:Proton Therapy / Q000191:economics / Q000295:instrumentation / Q000379:methods*
keywords: particle therapy; proton therapy; radiation oncology