Experience in fractionated stereotactic body radiation therapy boost for newly diagnosed nasopharyngeal carcinoma

PURPOSE: Radiotherapy is the most effective treatment for nasopharyngeal carcinoma (NPC). The aim of this study is to evaluate the efficacy and toxicity of fractionated stereotactic body radiation therapy (SBRT) boost for NPC. METHODS AND MATERIALS: Sixty-four patients with newly diagnosed, nonmetastatic NPC were treated with conventional radiotherapy 64.8-68.4 Gy followed by fractionated SBRT boost 12-15 Gy between January 2002 and July 2004. Most patients (72%) presented with Stage III-IV disease. Fifty-two patients also received cisplatin-based concurrent (38) or neoadjuvant (14) chemotherapy. The major endpoints were local control, overall survival, and complications. RESULTS: All patients finished the planned dose of radiotherapy. After a median follow-up of 31 months (range, 22-54), 15 patients developed tumor recurrences--3 in the nasopharynx, 4 in the neck, 5 in distant sites, 1 in both nasopharynx and neck, 2 in the neck and a distant site. The 3-year actuarial rate of local control was 93.1%, regional control 91.4%, freedom from distant metastasis 90.3%, and overall survival 84.9%, respectively. There were no Grade 4 acute or chronic radiation-related complications. CONCLUSIONS: Fractionated SBRT boost for NPC is technically feasible and provides good local control without any severe complications.