Reirradiation of locally recurrent nasopharyngeal carcinoma.

PURPOSE

To study the efficacy of reirradiation as salvage treatment in patients with locally recurrent nasopharyngeal carcinoma.

PATIENTS AND METHODS

Between 1993 and 2000, 20 consecutive patients (twelve males and eight females) with nasopharyngeal cancer, previously irradiated in different Hungarian institutions, were reirradiated for biopsy-proven locally recurrent tumor. Histologically, 85% of the patients had WHO type III, 5% type II, and 10% type I disease. Stages I-IV (AJCC 1997 staging system) were assigned to five (25%), seven (35%), five (25%), and three (15%) patients, respectively; none of them had distant metastases, and only eight (40%) displayed regional dissemination. The median time period between termination of primary treatment and local recurrence was 30 (range, 10-204) months. Brachytherapy was the method most frequently used: in ten cases alone (especially for rT1 tumors), and in eight cases in combination with external beam therapy. Two patients with locally advanced disease underwent external beam therapy only. The median dose in the event of brachytherapy alone was 20 Gy (4 x 5 Gy or 5 x 4 Gy, range, 16-36 Gy), and the dose range for exclusive external irradiation was 30-40 Gy. In cases of combined irradiation, a median 20-Gy brachytherapy (range, 16-40 Gy) was associated with 30-40 Gy of external irradiation. Radiotherapy was supplemented by neck dissection (six patients), nasopharyngectomy (one patient), or chemotherapy (eleven patients).

RESULTS

16 patients were reirradiated once, three twice, and one patient three times, with a median equivalent dose for tumor effect of 36 Gy (mean, 44 Gy; range, 19-117 Gy; the estimated alpha/beta-ratio was 10 Gy). The median equivalent dose of reirradiation for late effect on normal tissue (with an estimated 70% delivery of the tumor dose) amounted to 30 Gy (mean, 37 Gy; range, 13-101 Gy, estimated alpha/beta-ratio 3 Gy). After a median follow-up of 37 (range, 12-72) months, the overall survival was 60% (12/20). Seven of the twelve surviving patients are currently tumor-free. After primary irradiation, xerostomy occurred in all patients as an unavoidable side effect of treatment. Following reirradiation, a severe (grade 3 or higher) late toxicity (CTC criteria, version 2) has been observed in two tumor-free patients (10%) so far (necrosis of soft palate and paresis of glossopharyngeal nerve).

CONCLUSION

Retreatment of nasopharyngeal carcinoma with radiotherapy (preferably a combined modality), can result in longterm local control and survival in a substantial proportion of patients, at the price of an acceptable morbidity.