title: Robotic system-based fractionated stereotactic radiotherapy in locally recurrent nasopharyngeal carcinoma.
abstract: OBJECTIVE
  We reviewed survival, local control, and toxicity in patients with locally recurrent nasopharyngeal carcinoma (NPC) who had been treated with fractionated stereotactic radiotherapy (FSRT).
  
  
  METHODS
  Between June 2002 and March 2008, we retrospectively reviewed 35 patients with locally recurrent NPC treated using FSRT with CyberKnife. Gross tumor volumes ranged from 2.6 to 64.0 ml (median, 7.9 ml). Radiation doses were prescribed at the isodose line (75-84% of the maximum dose; median, 80%). The prescribed dose of FSRT ranged from 24 to 45 Gy (median, 33 Gy) in three or five fractions.
  
  
  RESULTS
  The overall survival (OS) rate, local failure-free survival (LFFS) rate, and disease progression-free survival (DPFS) rate at 5 years were 60%, 79%, and 74%, respectively. Twenty-three patients achieved complete response after FSRT. Only T stage at recurrence was an independent prognostic factor for OS and DPFS. Five patients exhibited severe late toxicity (Grade 4 or 5).
  
  
  CONCLUSIONS
  With regard to OS and LFFS, our study provided favorable outcomes. The incidence of severe late toxicities was acceptable in our study. FSRT would be considered as the alternative treatment of choice in re-irradiation for locally recurrent NPC.
authors.affiliation: Department of Radiation Oncology, Korea Institute of Radiological & Medical Sciences, Republic of Korea.
authors.forename: YoungSeok
authors.initials: Y
authors.lastname: Seo
authors.forename: HyungJun
authors.initials: H
authors.lastname: Yoo
authors.forename: SungYul
authors.initials: S
authors.lastname: Yoo
authors.forename: ChulKoo
authors.initials: C
authors.lastname: Cho
authors.forename: KwangMo
authors.initials: K
authors.lastname: Yang
authors.forename: Mi-Sook
authors.initials: MS
authors.lastname: Kim
authors.forename: ChulWon
authors.initials: C
authors.lastname: Choi
authors.forename: YoungJu
authors.initials: Y
authors.lastname: Shin
authors.forename: DongHan
authors.initials: D
authors.lastname: Lee
authors.forename: GukHang
authors.initials: G
authors.lastname: Lee
mesh_terms: D002277:Carcinoma / Q000401:mortality / Q000601:surgery*; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000601:surgery*; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000601:surgery*; D011379:Prognosis; D016634:Radiosurgery / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012371:Robotics; D015996:Survival Rate