title: Predictive value of skin invasion in recurrent head and neck cancer patients treated by hypofractionated stereotactic re-irradiation using a cyberknife.
abstract: BACKGROUND
  This study aimed to elucidate the influence of skin invasion in patients with recurrent head and neck cancer treated with re-irradiation using stereotactic radiotherapy.
  
  
  METHODS
  We reviewed 104 patients treated using CyberKnife in four institutions.
  
  
  RESULTS
  Nine cases of skin invasion were recognized (8.6 %). Larger tumors tended to exhibit skin invasion. The skin invasion (+) group showed a lower response rate (0/9, 0 %) than the skin invasion (-) group (56/95, 59 %) (p = 0.002). The skin invasion (+) group showed lower local control (LC) and progression free survival (PFS) rates, both 0 % at 6 months, than the skin invasion (-) group, which had a LC of 69 % (p = 0.0001) and a PFS of 48 % at 1 year (p = 0.0157). Median survival time and one-year survival rates for the skin invasion (+) and (-) groups were 6.6 vs. 15.3 months and 14 % vs. 59 % (p = 0.0005), respectively. No patient with skin invasion survived more than 14.4 months. The percentage of patients who developed grade 3 or higher toxicity was 44 % in the skin invasion (+) group and 18 % in the skin invasion (-) group (p = 0.14).
  
  
  CONCLUSIONS
  Skin invasion is an important predictor of poor prognosis in recurrent head and neck cancer after re-irradiation with stereotactic radiation therapy.
authors.affiliation: Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajiicho Kawaramachi Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan. hideya10@hotmail.com.|CyberKnife Center, Soseikai General Hospital, 126 Kami-Misu, Shimotoba Fushimi-ku, Kyoto, Japan. hideya10@hotmail.com.
authors.forename: Hideya
authors.initials: H
authors.lastname: Yamazaki
authors.affiliation: Department of Radiotherapy, Fujimoto Hayasuzu Hospital, Hayasuzu 17-1, Miyakonojo, Miyazaki, 885-0055, Japan. ogi@orange.ocn.ne.jp.
authors.forename: Mikio
authors.initials: M
authors.lastname: Ogita
authors.affiliation: Department of Radiology, Japanese Red cross Okayama Hospital, Aoe 2-1-1, Kita-ku, Okayama, Okayama, 700-8607, Japan. khimei@okayama-med.jrc.or.jp.
authors.forename: Kengo
authors.initials: K
authors.lastname: Himei
authors.affiliation: Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajiicho Kawaramachi Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan. satoaki@nakamura.pro.
authors.forename: Satoaki
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajiicho Kawaramachi Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan. gensuzumedkurume@yahoo.co.jp.
authors.forename: Gen
authors.initials: G
authors.lastname: Suzuki
authors.affiliation: Department of Radiation Oncology, National Hospital Organization Osaka National Hospital, 2-1-14, Hoenzaka, Chuo-ku, Osaka, Osaka, 540-0006, Japan. tkotsuma-osaka@umin.net.
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Kotsuma
authors.affiliation: Department of Radiation Oncology, National Hospital Organization Osaka National Hospital, 2-1-14, Hoenzaka, Chuo-ku, Osaka, Osaka, 540-0006, Japan. yoshidaisbt@gmail.com.
authors.forename: Ken
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan. yoshioka@radonc.med.osaka-u.ac.jp.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshioka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D006258:Head and Neck Neoplasms / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery*; D011379:Prognosis; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies