Clinical Outcomes and Dose-volume Analysis of Local Recurrence after Intensitymodulated Radiation Therapy for Nasopharyngeal Carcinoma Patients

Objective To evaluate the reasonability of treatment plan by analyzing the dose distribution of intensity-modulated radiation therapy plan for nasopharyngeal carcinoma(NPC) patients, especially for the recurrent NPC. Methods The intensity modulated radiation therapy(IMRT) for 339 patients with biopsyproven and newly diagnosed NPC were analyzed retrospectively, and 12 cases with locally recurrent NPC were performed in dosimetric analysis. Results The 1-year local control rate and regional control rate of the whole group were 98.1% and 99.3%, respectively. And the 2-year local control rate and regional control rate were 96.5% and 98.5%, respectively. Local treatments for 12 patients were failures and all the recurrent tumor volume were in fi eld. Conclusion With IMRT, excellent local control rates and tumor coverage are achieved, and adjacent organs at risk are protected well. Recurrent tumors volume in fi eld suggest that smaller target volume defi nition and increasing dose for local primary tumor would improve local control rate.