title: Treatment outcomes of particle radiotherapy using protons or carbon ions as a single-modality therapy for adenoid cystic carcinoma of the head and neck.
abstract: OBJECTIVE
  The aim of this study was to retrospectively analyse the outcomes of cases of adenoid cystic carcinomas (ACCs) of the head and neck that were treated at a single institution with particle therapy consisting of either protons or carbon ions.
  
  
  METHODS
  Between February 2002 and March 2012, 80 patients were treated with proton therapy (PT) or carbon ion therapy (CIT) alone. PT and CIT were employed in 40 (50%) patients each, and more than half of the patients received 65.0 GyE in 26 fractions (n=47, 59%).
  
  
  RESULTS
  The median duration of follow-up was 38 months (range, 6-115 months). For all patients, the 5-year for overall survival (OS) rate, progression-free survival (PFS) rate, and local control (LC) rate were 63%, 39%, and 75%, respectively. No significant differences between PT and CIT were observed. The 5-year LC rates for T4 and inoperable cases were 66% and 68%, respectively. Twenty-one patients (26%) experienced grade 3 or greater late toxicities, including three patients who developed grade 5 bleeding from nasopharyngeal ulcers.
  
  
  CONCLUSIONS
  Particle radiotherapy for ACC achieves favourable LC, and its efficacy in inoperable or T4 cases is promising. There were no significant differences between PT and CIT in terms of OS, PFS and LC.
authors.affiliation: Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan. Electronic address: mtakagidear@gmail.com.
authors.forename: Masaru
authors.initials: M
authors.lastname: Takagi
authors.affiliation: Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Demizu
authors.affiliation: Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Hashimoto
authors.affiliation: Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Mima
authors.affiliation: Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Terashima
authors.affiliation: Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Fujii
authors.affiliation: Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
authors.forename: Dongcun
authors.initials: D
authors.lastname: Jin
authors.affiliation: Department of Radiology, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Yasue
authors.initials: Y
authors.lastname: Niwa
authors.affiliation: Division of Otorhinolaryngology-Head and Neck Surgery, Kobe University Graduate School of Medicine, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Morimoto
authors.affiliation: Department of Radiation Physics, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Akagi
authors.affiliation: Department of Biostatistics, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Daimon
authors.affiliation: Section of Radiation Oncology, Kobe University Graduate School of Medicine, Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Sasaki
authors.affiliation: Department of Radiology, Medipolis Proton Therapy and Research Center, Ibusuki, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hishikawa
authors.affiliation: Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
authors.forename: Mitsuyuki
authors.initials: M
authors.lastname: Abe
authors.affiliation: Center for Radiation Oncology, Dokkyo Medical University, Shimotsuga-gun, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Murakami
authors.affiliation: Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Japan.
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Fuwa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003528:Carcinoma, Adenoid Cystic / Q000401:mortality / Q000532:radiotherapy*; D018572:Disease-Free Survival; D005260:Female; D006258:Head and Neck Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D063193:Heavy Ion Radiotherapy / Q000379:methods*; D006801:Humans; D007477:Ions / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D061766:Proton Therapy; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D007477:Ions
keywords: Adenoid cystic carcinoma; Carbon ion therapy; Particle therapy; Proton therapy