Fractionated stereotactic radiosurgery for 50 patients with recurrent or residual nasopharyngeal carcinoma.

Abstract

This study was conducted to evaluate the clinical value of fractionated stereotactic radiosurgery (FSRS) as a boost treatment in 44 patients with residual or recurrent nasopharyngeal carcinoma after conventional radiotherapy (70-80 Gy) or a second course of radiotherapy (50 Gy) or as salvage treatment in 6 patients with recurrent nasopharyngeal carcinoma after a first or second course of radiotherapy at the primary site. From September 20, 1995 to December 30, 1998, 50 patients were treated with FSRS with 6 MV of photons. The total FSRS dose was 14-35 Gy (median dose 24) prescribed at 1-4 centers on the 60-90% isodose curves normalized to the isocenter by multiple fractions of 6-8, 12, or 15 Gy, with interfraction intervals of 4-6 days. Thirty-eight patients (76%) had a complete tumor response, 9 (18%) had a partial response, and 3 (6%) were not assessable. The overall rate of survival was 83.6% at 1 year, 65.0% at 2 years, and 59.6% at 3 years. The overall disease-free survival rate among patients with residual tumor was 89.94% at 1 year, 73.97% at 2 years, and 73.97% at 3 years. Patients who were treated for recurrent lesions or who received FSRS as salvage therapy had a 46.53% rate of disease-free survival at both 1 and 2 years after therapy. FSRS is strongly indicated for recurrent or residual nasopharyngeal carcinoma at the primary site.