@article{oai:repo.qst.go.jp:00046787,
 author = {Koto, Masashi and Hasegawa, Azusa and Takagi, Ryo and Fujikawa, Akira and Morikawa, Takamichi and Kishimoto, Riwa and Jingu, Keiichi and Tsujii, Hirohiko and Kamada, Tadashi and 小藤 昌志 and 長谷川 安都佐 and 高木 亮 and 藤川 陽 and 森川 貴迪 and 岸本 理和 and 辻井 博彦 and 鎌田 正},
 issue = {1},
 journal = {Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology},
 month = {Dec},
 note = {BACKGROUND AND PURPOSE: This study aimed to determine the risk factors for radiation-induced brain injury (RIBI) after carbon ion radiotherapy (CIRT) for treating skull base tumors.
\nMATERIALS AND METHODS: Between April 1997 and January 2009, CIRT at a total dose of 48.0-60.8Gy equivalent (GyE) was administered in 16 fractions to 47 patients with skull base tumors. Of these patients, 39 who were followed up with magnetic resonance imaging (MRI) for more than 24months were analyzed. RIBI was assessed according to the MRI findings based on the Late Effects of Normal Tissue-Subjective, Objective, Management, Analytic criteria; clinical symptoms were assessed according to the Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer tables. The correlations of clinical and dosimetric parameters with incidence of ⩾grade 2 RIBI were retrospectively analyzed.
\nRESULTS: The median follow-up period was 67months. The 5-year actuarial likelihoods of ⩾grade 2 RIBI and ⩾grade 2 clinical symptoms were 24.5% and 7.0%, respectively. Multivariate analysis demonstrated that the brain volume receiving more than 50GyE (V50) was a significant risk factor for the development of ⩾grade 2 RIBI (p=0.004).
\nCONCLUSION: V50 was a significant risk factor for ⩾grade 2 RIBI after CIRT using a 16-fraction regimen.},
 pages = {25--29},
 title = {Risk factors for brain injury after carbon ion radiotherapy for skull base tumors.},
 volume = {111},
 year = {2013}
}