Comparison of effectiveness of intensity-modulated radiotherapy with conventional two-dimensional radiotherapy for patients with locally recurrent nasopharyngeal carcinoma / 中华放射肿瘤学杂志

ABSTRACT

ObjectiveTo compare the efficacy and side-effects in locally recurrent nasopharyngeal carcinoma (NPC) treated by intensity-modulated radiotherapy (IMRT) and two-dimensional conventional radiotherapy (2DCRT).MethodsAmong the 292 newly diagnosed,nonmetastatic recurrent NPC,211were treated with IMRT and 81 with 2DCRT.All patients were staged according to the seventh edition of the UICC 2009 staging system.Kaplan-Meier and Logrank methods were used for survival analysis.A Cox proportional hazard model was used to examine prognostic factors.ResultsThe follow-up rate was 91.8％,there are 38 patients in 2DCRT and 106 patients in IMRT group was followed more than 3 years.There were significant differences in the 3-year actuarial overall survival (OS) rate ( 36.9％ and 51.3％,x2 =8.44,P =0.004) and local progression-free survival (LRFS) rate (63.3％ and 86.0％,x2 =13.83,P =0.000),and no significant differences in actuarial distant metastasis free survival rates (79.0％ and 83.5％,x2 =0.25,P=0.618 ) between the 2DCRT group and the IMRT group.Multivariate analysis showed that T category and IMRT ( yes vs.no) were the independently prognostic factors for OS and LRFS ( x2 =9.51,5.20,P =0.002,0.023 and x2 =4.84,9.24,P =0.027,0.002 ).The incidence of grade 3and4 trismus and radiation-induced encephalopathy were 19.9％,8.1％ for the IMRT group and 43.2％,24.7％ for the 2DCRT group ( x2 =16.37,P =0.000 and x2 =14.64,P =0.000).Whereas,severe mucosa necrosis and/or massive hemorrhage in the nasopharynx was observed in IMRT group which was not common in 2DCRT (33.2％∶7.4％,x2 =20.19,P=0.000).ConclusionsHigher local tumor control and overall survival were achieved by IMRT than 2DCRT,the incidence of severe trismus and radiation-induced encephalopathy was also reduced by IMRT,in cost of a higher incidence of mucosa necrosis and/or massive hemorrhage in the nasopharynx.