Comparative study on prophylactic irradiation to the whole neck and to the upper neck for patients with neck lymph node-negative nasopharyngeal carcinoma.

Abstract

The purpose of this study was to investigate the prophylactic irradiation volume to neck drainage areas for patients with N0 classification nasopharyngeal carcinoma (NPC) treated by intensity-modulated radiotherapy (IMRT). From January 2003 to October 2008, 270 patients with N0 classification (American Joint Committee on Cancer [AJCC] 2002 staging system) NPC who had undergone IMRT were retrospectively analyzed. Among all the patients, 171 patients received prophylactic upper-neck irradiation, and 99 patients received prophylactic whole-neck irradiation. At a median follow-up of 65.1 months (range, 4-106 months). The 5-year overall survival (OS), nodal recurrence-free survival (NRFS), and distant metastasis-free survival (DMFS) rates of the upper neck group and the whole neck group were 93.6% vs 90.9% (p = .553), 99.4% vs 99.0% (p = .278), and 98.8% vs 94.9% (p = .128), respectively. A total of 3 neck recurrences were found, including 2 from the whole neck group and 1 from the upper neck group. The latter (0.6%) was an out-of-field recurrence. Prophylactic irradiation to the upper neck (levels II, III, and VA) may be feasible for patients with neck lymph node-negative NPC.