Stereotactic radiosurgery as a salvage treatment for locally persistent and recurrent nasopharyngeal carcinoma

Background. The purpose of this work was to study the efficacy of stereotactic radiosurgery as a salvage treatment in patients with locally persistent and recurrent nasopharyngeal carcinoma (NPC). Methods. Between March 1996 and August 1997, 10 patients with locally persistent or recurrent NPC were treated by linac-based stereotactic radiosurgery. Four patients had radiosurgery for persistent disease after a first course of radiotherapy, 3 had radiosurgery as a boost after reirradiation for local recurrence, and 3 had radiosurgery for disease that recurred after reirradiation. The tumor volume ranged from 1.3 to 23.7 cc (median: 5.2). Treatment was prescribed at 80% isodose line and ranged from 12 to 18 Gy (median: 13.4), with a mean tumor surface dose ranged from 10-21 Gy (median: 14). The median clinical followup was 10.5 months (range 8-27), and the median imaging follow-up was 9.5 months (range 6-26). Results. One patient had complete regression of tumor after radiosurgery, five had reduction in tumor size, three had no change, and one had progression of tumor. The overall response rate to radiosurgery was 60% (6/10), with 10% (1/10) developing in-field progression. Excluding patients receiving radiosurgery as a boost treatment after reirradiation, the response rate was 57% (4/7) and none developed in-field progression. Only one patient developed a new cranial neuropathy in the absence of disease progression. Conclusion. In selected patients with locally persistent or recurrent NPC, stereotactic radiosurgery can be considered as a salvage treatment with good short-term local control. The complications appear to be minimal except for treating recurrence in the cavernous sinus, Early results are encouraging although more experience and longer follow-up are still needed to better define the role of radiosurgery in the management of persistent and recurrent NPC. (C) 1999 John Wiley & Sons, Inc.