Stereotactic Radiotherapy for Locally Recurrent Nasopharyngeal Carcinoma

Abstract

To study the treatment outcome in patients with locally recurrent nasopharyngeal carcinoma (NPC) who were treated with stereotactic radiotherapy (SRT). 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. 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. 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.