Adjuvant High-Dose Rate Brachytherapy after Chemoradiation for Treatment of Early T-Stage Nasopharyngeal Carcinoma

Abstract

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.