@article{oai:repo.qst.go.jp:00048357,
 author = {Saitoh, Jun-ichi and Koto, Masashi and Demizu, Yusuke and Suefuji, Hiroaki and Ohno, Tatsuya and Tsuji, Hiroshi and Okimoto, Tomoaki and Shioyama, Yoshiyuki and Nemoto, Kenji and Nakano, Takashi and Kamada, Tadashi and 小藤 昌志 and 末藤 大明 and 大野 達也 and 辻 比呂志 and 沖本 智昭 and 塩山 善之 and 根本 建二 and 中野 隆史 and 鎌田 正},
 issue = {2},
 journal = {Int J Radiation Oncol Biol Phys},
 month = {May},
 note = {Purpose: Head and neck (HN) adenocarcinoma is rare, and to date, there have been no
reports of prospective studies. We retrospectively evaluated the efficacy and safety of
carbon-ion radiation therapy (C-ion RT) for HN adenocarcinoma in institutions in
Japan.
Methods and Materials: HN adenocarcinoma patients with N0M0 or N1M0 disease
who were treated with C-ion RT at institutions in Japan between November 2003
and December 2014 were analyzed retrospectively. We enrolled 47 patients (30 male
and 17 female patients; median age, 60 years) with HN adenocarcinoma.
Results: Primary sites included the nasal and paranasal sinus in 21 patients, orbit in
11, salivary grand in 7, oral cavity and pharynx in 6, and acoustic organ in 2.
Thirty-two patients had T4 tumors, 6 had T3, and 6 had T2. Forty-five patients
received a diagnosis of N0 disease, whereas 2 had N1 disease. The median total dose
of C-ion RT and the number of fractions were 64.0 Gy (relative biological effectiveness)
and 16 fractions, respectively. The median follow-up period was 51 months
(range, 6-118 months). The 2- and 5-year overall survival rates were 87.9% and
60.4%, respectively, and the 2- and 5-year local control rates were 83.3% and
79.3%, respectively. Multivariate analysis showed that operability (patients with
operable tumors) (PZ.045) and fractionation (16 fractions) (PZ.010) were significant independent prognostic factors for better overall survival. No grade 5 late morbidities
were observed. Grade 4 late morbidities were observed in 4 patients, and all of
these grade 4 morbidities were visual impairments. All 4 patients with grade 4 visual
impairment had T4 tumors in the nasopharynx or paranasal sinuses, which implied
inoperable tumors with orbital or brain invasion.},
 pages = {442--449},
 title = {A Multicenter Study of Carbon-Ion Radiation Therapy for Head and Neck Adenocarcinoma},
 volume = {99},
 year = {2017}
}