Stereotactic radiotherapy for locally recurrent nasopharyngeal carcinoma

Objective: To determine the efficacy of stereotactic radiotherapy (SRT) in the treatment of recurrent nasopharyngeal carcinoma. Study Design: A retrospective review of the outcome of SRT for patients with recurrent nasopharyngeal carcinomas following definitive conventional radiation therapy. Methods: Five patients were treated with daily static multiportal irradiation. Two Gy was administered with eight isocentric portals in a single plane 5 days a week, and the plane was changed for every 20 to 30 Gy. Of these patients, three had poorly differentiated squamous cell carcinoma. Tumor sizes ranged from 1 to 15 cm(3), with a median size 3.2 cm3. Median follow-up time from SRT was 34 months (range, 4-61 mo). Results: Four of five recurrent tumors responded well and achieved complete regression. Three patients have survived without evidence of local recurrence with a median follow-up time of 34 months. Marginal recurrence was observed at the posterosuperior wall in a patient with adenoid cystic carcinoma at 30 months after SRT. One patient who received SRT after the two complete courses of radiation therapy died 6 months after SRT as a result of rupture of a branch of the left carotid artery, but autopsy revealed no local residual tumor. Conclusions: Stereotactic radiotherapy with isocentric multiportals in one plane, which is changed at every 20 to 30 Gy, can provide local control with acceptable toxicity in patients with recurrent nasopharyngeal carcinoma, but increased clinical experience and longer follow-up Rill be necessary to evaluate the overall role of this technique in nasopharyngeal carcinoma.