title: Frequency, outcome and prognostic factors of carotid blowout syndrome after hypofractionated re-irradiation of head and neck cancer using CyberKnife: a multi-institutional study.
abstract: OBJECTIVE
  Re-irradiation has attracted attention as a potential therapy for recurrent head and neck tumors. However, carotid blowout syndrome (CBS) has become a serious complication of re-irradiation because of the associated life-threatening toxicity. Determining of the characteristics of CBS is important. We conducted a multi-institutional study.
  
  
  METHODS
  Head and neck carcinoma patients (n=381) were treated with 484 re-irradiation sessions at 7 Japanese CyberKnife institutions between 2000 and 2010.
  
  
  RESULTS
  Of these, 32 (8.4%) developed CBS, which proved fatal that median survival time after CBS onset was 0.1 month, and the 1-year survival rate was 37.5%. The median duration between re-irradiation and CBS onset was 5 months (range, 0-69 months). Elder age, skin invasion, and necrosis/infection were identified as statistically significant risk factors after CBS by univariate analysis. The presence of skin invasion at the time of treatment found only in postoperative case, is identified as only statistically significant prognostic factor after CBS in multivariate analysis. The 1-year survival rate for the group without skin invasion was 42%, whereas no patient with skin invasion survived more than 4 months (0% at 1 year, p=0.0049).
  
  
  CONCLUSIONS
  Careful attention should be paid to the occurrence of CBS if the tumor is located adjacent to the carotid artery. The presence of skin invasion at CBS onset is ominous sign of lethal consequences.
authors.affiliation: Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan. hideya10@hotmail.com
authors.forename: Hideya
authors.initials: H
authors.lastname: Yamazaki
authors.forename: Mikio
authors.initials: M
authors.lastname: Ogita
authors.forename: Naohiro
authors.initials: N
authors.lastname: Kodani
authors.forename: Satoakai
authors.initials: S
authors.lastname: Nakamura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inoue
authors.forename: Kengo
authors.initials: K
authors.lastname: Himei
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Kotsuma
authors.forename: Ken
authors.initials: K
authors.lastname: Yoshida
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshioka
authors.forename: Koichi
authors.initials: K
authors.lastname: Yamashita
authors.forename: Hiroki
authors.initials: H
authors.lastname: Udono
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002340:Carotid Artery Diseases / Q000453:epidemiology* / Q000401:mortality; D019583:Dose Fractionation, Radiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000150:complications / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D016634:Radiosurgery; D012867:Skin / Q000473:pathology; D013577:Syndrome; D047368:Tumor Burden
keywords: Carotid blowout syndrome; Head and neck cancer; Re-irradiation; Stereotactic radiotherapy