@article{oai:repo.qst.go.jp:00048949,
 author = {Ikawa, Hiroaki and Koto, Masashi and Takagi, Ryo and Ebner, Daniel and Hasegawa, Azusa and Naganawa, Kensuke and Takenouchi, Toshinao and Nagao, Toshitaka and Nomura, Takeshi and Shibahara, Takahiko and Tsuji, Hiroshi and Kamada, Tadashi and 伊川 裕明 and 小藤 昌志 and 高木 亮 and エブナー ダニエル and 長谷川 安都佐 and 長縄 憲亮 and 武内 利直 and 長尾 俊孝 and 柴原 孝彦 and 辻 比呂志 and 鎌田 正},
 issue = {3},
 journal = {Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology},
 month = {May},
 note = {Purpose: The aim of this study was to evaluate the effect of histological subtypes of head and neck adenoid cystic carcinoma (ACC) on the results of carbon-ion radiotherapy (CIRT).
Material and methods: Of the 113 patients with ACC who were treated with CIRT between December 2006 and July 2013, 100 patients with identified histological subtypes were enrolled in this study. CIRT at a total dose of 57.6 or 64.0 Gy (RBE) was administered in 16 fractions. Histological grading was defined as the presence or absence of a solid growth pattern.
Results: Median follow-up was 60 months. 5-Year local control (LC), overall survival (OS) and distant metastasis free survival (DMFS) of all patients were 68.6%, 74.8% and 65.7%, respectively. On multivariate analysis, the prescribed dose (p = 0.001) and gross tumor volume (p = 0.002) were significant independent risk factors for LC. No significant difference for local control of solid/non-solid growth patterns was found (p = 0.093). Solid growth pattern was an independent risk factor for both OS (p = 0.033) and DMFS (p = 0.024).
Conclusions: CIRT appears able to locally control solid growth pattern ACC in the head and neck. Improved intervention is needed to extend DMFS and OS.},
 pages = {387--393},
 title = {Prognostic factors of adenoid cystic carcinoma of the head and neck in carbon-ion radiotherapy: The impact of histological subtypes},
 volume = {123},
 year = {2017}
}