title: Stereotactic radiotherapy for locally recurrent nasopharyngeal carcinoma.
abstract: OBJECTIVE
  To study the treatment outcome in patients with locally recurrent nasopharyngeal carcinoma (NPC) who were treated with stereotactic radiotherapy (SRT).
  
  
  METHODS
  Thirty patients with non-metastatic, locally recurrent NPC who were treated with curative intent between 1998 and 2002 were retrospectively analyzed. The International Union Against Cancer T-stage distribution at recurrence (rT) was as follows: rT1-14, rT2-7, rT3-3, and rT4-6. All patients were treated with SRT with a daily fractional dose of 2.5-4.5 Gy (median, 3 Gy) in 8-22 fractions (median, 18 fractions). Total equivalent dose (TED) was calculated by the linear-quadratic formula without a time factor correction.
  
  
  RESULTS
  The 5-year actuarial overall survival rate, disease-specific survival rate, and local failure-free survival (LFFS) rate for the whole group were 40%, 41.4%, and 56.8%, respectively. The 3-year LFFS rates of rT1-2 and rT3-4 diseases were 65% and 66.7%, respectively. Seven of nine patients who received a TED <55 Gy recurred locally compared with 4 of 21 patients who received > or =55 Gy. Their corresponding 5-year LFFS rates were 22.2% and 75.8% (p = 0.005). The TED was the only factor significant in affecting the local control on univariate analyses.
  
  
  CONCLUSIONS
  SRT is an effective treatment for locally recurrent NPC. TED > or =55 Gy should be given to secure a higher local control rate. The late complication rates were acceptable for patients with rT1-2 disease. For patients with rT3-4 disease, more works need to be done to further decrease the late complications.
authors.affiliation: Department of Clinical Oncology, Queen Mary Hospital, Hong Kong, People's Republic of China. tw_leung@hotmail.com
authors.forename: To-Wai
authors.initials: TW
authors.lastname: Leung
authors.forename: Victy Y W
authors.initials: VY
authors.lastname: Wong
authors.forename: Stewart Y
authors.initials: SY
authors.lastname: Tung