Dosimetric comparison and observation of three-dimensional conformal radiotherapy for recurrent nasopharyngeal carcinoma

The aim of the study was to investigate the effect of three-dimensional conformal radiation therapy (3D-CRT) on nasopharyngeal carcinoma (NPC) and the incidence of complications. Between May 2010 and June 2012, 141 patients diagnosed with local recurrence of NPC due to cranial base lesions or cranial nerve symptoms, confirmed by pathology biopsy and/or by CT/MRI, were included in the present study. In accordance with the principle of randomized control, the patients were divided into three groups and treated with three different doses of 3D-CRT. The planned radiotherapy doses of 3D-CRT were 58/1.8-2 Gy, 62/1.8-2 Gy and 68/1.8-2 Gy, respectively. The survival rate, disease-free survival (DFS) rate and local control rate of the three groups of patients were compared as well as the adverse reactions observed after radiotherapy. The prognoses of NPC patients were analyzed by univariate and multivariate analyses. The follow-up rate of the study was 100%. The 5-year overall survival, DFS, and locoregional recurrence-free survival rates were: 43.2 vs. 64.53 vs. 75%, 29.13 vs. 42.82 vs. 39.7% and 30.76 vs. 44.19 vs. 45.4%, respectively. In addition, 62/1.8-2 Gy was similar in treatment effects to 68/1.8-2 Gy, but 68/1.8-2 Gy showed more adverse reactions than 62/1.8-2 Gy. Thus, 62/1.8-2 Gy can be used as a safe and effective dose for 3D-CRT treatment of NPC. Univariate and multivariate analyses showed that age may be the main prognostic factor of patients with NPC. In conclusion, 3D-CRT with a dose of 62/1.8-2 Gy is a safe, effective and tolerable treatment for NPC patients with good clinical value.