Treatment results of intensity-modulated radiotherapy for nasopharyngeal carcinoma: an analysis of 147 patients / 中华放射肿瘤学杂志

ABSTRACT

Objective To evaluate the efficacy of intensity-madulated radiotherapy(IMRT) as the primary treatment in nasopharyngeal carcinoma (NPC). Methods Between November 2001 and March 2006,147 newly diagnosed NPC patients were treated with IMRT. The disease was Stage I in 3 patients, Stage Ⅱ in 35,Stage Ⅲ in 67 and Stage Ⅳ in 42. For T1-2 disease,the prescription dose was 70 Gy to the gross tumor volume( GTVnx) and positive neck nodes ,60 Gy to the planning target volume I, and 50-56 Gy to the clinically negative neck. For T3-4 disease,the prescription dose was 74-78 Gy to GTVnx. The local control rate(LC),overall survival (OS), disease-free survival (DFS) and distant metastasis-free survival (DMFS) were estimated by Kaplan-Meier method. Results The 3-year LC, OS, DFS and DMFS of the whole group were 93.2% ,93.5% ,72.6% and 74.4% ,respectively. T stage was a significant predictor of LC and OS. For patients with T1-2 and T3-4 disease,the LC was 100% and 86.9% (P=0.007) and OS was 95.5% and 91.3% (P=0.030), respectively. N stage was a significant predictor of OS, DFS and DMFS(P=0.03,0.004 and 0.0004,respectively). The grade Ⅰ+ Ⅱ and Ⅲ acute toxieities of parotid were 96.6% and 1.4%. The rate of grade Ⅱ xerostomia at 3-month, 6-month, 1-year and 2-year after radiotherapy were 43.0%, 12.0% ,4.9% and 3.2%. Conclusions The treatment results are promising according to our target definition and dose prescription protocol for nasopharyngeal carcinoma.