Abstract: Objective · To retrospectively analyze the treatment outcome, radiation toxicity and the prognostic factors in patients with locally recurrent nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT). Methods · January 2012 to August 2016, a total of44 patients who were diagnosed with locally recurrent NPC and received reirradiation with IMRT were included in the study. Among all the patients, there were 33 male patients and 11 female patients, the median age of whom was 51.5 years (range 25–76 years). According to the 2012 American Joint Committee on Cancer Stage Classification Cancer Staging Manual, the distribution of disease restaging was 25.0% for stage rT1, 22.7% for stage rT2,22.7% for stage rT3 and 29.6% for stage rT4. The median recurrence interval was 28 months (range 5–168 months). The median prescribed dose to the target volume was 66 Gy (range 54–70 Gy). The toxicities were evaluatedRadiation Therapy Oncology Group (RTOG). The survival rate was determined using the Kaplan-Meier method. Prognostic factors were analyzedLog-rank tests and Cox proportional hazard model. Results · Three months after reirradiation therapy, the complete remission rate, the partial remission rate, the stabilization rate and the progressive rate were 18.2%(8/44), 47.7% (21/44), 27.3% (12/44) and 6.8% (3/44), respectively. The 3-year overall survival (OS), 3-year progression free survival (PFS), 3-year local recurrence-free survival and distant metastasis rates were 56.8%, 43.2%, 58.9% and 11.4%, respectively. In a univariate analysis, age, recurrent T stage, recurrence interval, adverse reactions and response to re-IMRT were significant prognostic factors for OS and recurrent T stage was also an independent prognostic factor for PFS. In a multivariate analysis, recurrent T stage remained significant for OS and PFS. During follow-up, 21 patients died. Five patients died of nasopharynx hemorhea. Grade 3–4 toxicities were reported in 12 patients. Conclusion · Re-irradiation with IMRT is available to improve OS and thus is a reasonable choice for patients with locally recurrent NPC. However, the incidence of severe adverse events is still high. Younger ages lower recurrent T stage and longer recurrent interval are independent prognostic factors for OS of recurrent NPC.

Key words: nasopharyngeal carcinoma, recurrent, intensity-modulated radiotherapy, prognosis