Fractionated stereotactic radiotherapy in residual or recurrent nasopharyngeal carcinoma

The aim of this study was to evaluate results of fractionated stereotactic radiotherapy (FSRT) in patients with residual or recurrent nasopharyngeal carcinoma (NPC) in terms of local progression-free (LPFS) and overall survival (OS) rate and complications after treatment. There were 32 residual or recurrent NPC patients treated with FSRT using linac- based radiosurgery system. Time from the previous radiotherapy to FSRT was 1-165 months (median, 15). Two patients were treated for the second and one for the third recurrence. Thirteen patients (40.6%) also received chemotherapy with FSRT. Tumor volume ranged from 6.2-215 cc (median, 44.4). Average FSRT dose was 17-59.4 Gy (median, 34.6) in 4-25 fractions (median, 6) in 1 - 5.5 weeks (median, 3). Median follow-up time was 25.5 (3-67) months. LPFS rate at 1 and 3 years after FSRT was 67.8% and 37.9%. OS rate at 1 and 3 years was 89.7% and 71.2%. If all patients who had tumor progression with no further follow- up were assumed dead, the OS rate at 1 and 3 years would be 75.0% and 37.9%. Univariate analysis showed better local tumor control in patients with tumor volume <= 100 cc (p = 0.04) or in those without chemotherapy (p = 0.0005). Only chemotherapy retained significance in multivariate analysis (hazard ratio 5.47, 95% CI 1.86-16.04). Eight patients (25%) had complications after FSRT, all grade 2-3 except 1 grade 4 with complete recovery.