Sequential external beam radiotherapy and high-dose-rate intracavitary brachytherapy in T1 and T2 nasopharyngeal carcinoma: an evaluation of long-term outcome.

OBJECTIVES/HYPOTHESIS: The standard treatment for nonmetastatic nasopharyngeal carcinoma (NPC) is external beam radiotherapy (EBRT), with or without chemotherapy. Because local control in NPC is an independent prognostic factor for distant metastases and survival, various dose-escalation strategies have been used to reduce recurrences at the primary site. The objective of this report was to evaluate the outcome of adjuvant high-dose-rate intracavitary brachytherapy (HDRIB) in patients with T1 and T2 NPC. STUDY DESIGN AND METHODS: Thirty-three consecutive patients with T1 and T2 NPC were treated prospectively according to a standardized institutional protocol between March 1999 and July 2001. Seventeen patients with stage I/II disease were treated with EBRT to 66 Gy followed by HDRIB (10 Gy in 2 weekly 5 Gy fractions). The remaining 16 patients with Stage III to IVb disease received chemotherapy in addition to radiation. All patients were assessed for treatment response, local control, survival, and toxicity. RESULTS: Median follow-up for all surviving patients was 67 (range 52-76) months. Local failure occurred in two patients; both subsequently underwent successful salvage treatments. Three patients died of metastatic disease, whereas two died of unrelated causes. Five year local control, overall survival, and disease-free survival rates were 93.8%, 83.9% and 78.4%, respectively. All patients experienced acute or late radiotherapy-related sequelae. However, no grade 4/5 toxicities were reported. Specifically, toxicities that could be attributed to brachytherapy were not seen, except for in one patient who developed severe choanal stenosis. CONCLUSIONS: EBRT supplemented by HDRIB produced superior local control rates for T1 and T2 NPC at 5 years of follow-up, with acceptable rates of acute and late toxicities.

Adjuvant high-dose rate brachytherapy after chemoradiation for treatment of early T-stage nasopharyngeal carcinoma.

The local control of nasopharyngeal carcinoma after conventional radiotherapy has historically been suboptimal. Recently, investigators have reported improved outcomes for this patient population with the use of combined chemoradiotherapy. The purpose of this analysis of our prospective treatment protocol was to evaluate the additional value of high-dose rate intracavitary brachytherapy (HDRIB) on the disease response, local control, and survival. Between March 1999 and January 2001, 16 patients with newly diagnosed locally advanced (stage III and IV) nasopharyngeal carcinoma were treated prospectively at the Radiation Oncology Department of the National University Hospital of Singapore. All patients were staged according to the AJCC (1997) Staging System and had early T stages (T1 and T2). Treatments included concurrent external beam radiotherapy (EBRT) and chemotherapy as follows: 66 Gy to the primary tumor in conventional fractionation with cisplatin based concurrent chemotherapy followed by adjuvant cisplatin and 5-fluorouracil (5-FU) chemotherapy. Ten Gy of HDRIB in 2 weekly fractions were delivered after the completion of EBRT to all 16 patients. All patients were evaluable for treatment response, local control, survival, and toxicity analysis. The median follow-up for the whole group of patients was 18 months (range: 10-34 months). All patients obtained pathologic complete response at the primary site at 4 months after the completion of the treatment. At the time of this analysis, 15 (93.8%) patients are alive with no evidence of disease. One patient (6.2%) developed locoregional recurrence in the neck at 9 months, and distant metastasis at 11 months after the completion of treatment. Our experience has shown adjuvant HDRIB after concurrent chemoradiation offers encouraging disease response, local control, and survival. A prospective study is being planned to further evaluate the role of adjuvant HDRIB after concurrent chemoradiation on treatment outcome.