title: Proton-beam therapy for olfactory neuroblastoma.
abstract: OBJECTIVE
  To analyze the feasibility and efficacy of proton-beam therapy (PBT) for olfactory neuroblastoma (ONB) as a definitive treatment, by reviewing our preliminary experience. Olfactory neuroblastoma is a rare disease, and a standard treatment strategy has not been established. Radiation therapy for ONB is challenging because of the proximity of ONBs to critical organs. Proton-beam therapy can provide better dose distribution compared with X-ray irradiation because of its physical characteristics, and is deemed to be a feasible treatment modality.
  
  
  METHODS
  A retrospective review was performed on 14 patients who underwent PBT for ONB as definitive treatment at the National Cancer Center Hospital East (Kashiwa, Chiba, Japan) from November 1999 to February 2005. A total dose of PBT was 65 cobalt Gray equivalents (Gy(E)), with 2.5-Gy(E) once-daily fractionations.
  
  
  RESULTS
  The median follow-up period for surviving patients was 40 months. One patient died from disseminated disease. There were two persistent diseases, one of which was successfully salvaged with surgery. The 5-year overall survival rate was 93%, the 5-year local progression-free survival rate was 84%, and the 5-year relapse-free survival rate was 71%. Liquorrhea was observed in one patient with Kadish's stage C disease (widely destroying the skull base). Most patients experienced Grade 1 to 2 dermatitis in the acute phase. No other adverse events of Grade 3 or greater were observed according to the RTOG/EORTC acute and late morbidity scoring system.
  
  
  CONCLUSIONS
  Our preliminary results of PBT for ONB achieved excellent local control and survival outcomes without serious adverse effects. Proton-beam therapy is considered a safe and effective modality that warrants further study.
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan. westvill@med.kobe-u.ac.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Nishimura
authors.forename: Takashi
authors.initials: T
authors.lastname: Ogino
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Kawashima
authors.forename: Keiji
authors.initials: K
authors.lastname: Nihei
authors.forename: Satoko
authors.initials: S
authors.lastname: Arahira
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Onozawa
authors.forename: Shoichi
authors.initials: S
authors.lastname: Katsuta
authors.forename: Teiji
authors.initials: T
authors.lastname: Nishio
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D018304:Esthesioneuroblastoma, Olfactory / Q000175:diagnosis / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000517:prevention & control*; D009669:Nose Neoplasms / Q000175:diagnosis / Q000532:radiotherapy*; D061766:Proton Therapy; D012189:Retrospective Studies; D011522:Protons
chemical_list: D011522:Protons