Value of FDG PET-CT in outcome assessment and prognostic evaluation for recurrent nasopharyngeal carcinoma / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the value of FDG PET-CT in the outcome assessment and prognostic evaluation for recurrent nasopharyngeal carcinoma (rNPC).Methods From January 2008 to December 2013,92 rNPC patients were treated in our center,who were histologically or radiologically diagnosed and re-staged according to the 2008 clinical staging system for nasopharyngeal carcinoma in China.The numbers of patients in stage Ⅰ,stage Ⅱ,stage Ⅲ,and stage Ⅳ were 8,11,39,and 34,respectively.According to the recurrent T stage (rT),the numbers of patients in rT1,rT2,rT3,and rT4 were 10,11,38,and 33,respectively.Twenty-eight patients had recurrence in the neck lymph nodes.All patients underwent pretreatment FDG PET-CT for the whole body or head/neck,and treated by radiotherapy with or without chemotherapy.The relationship of maximum standard uptake value (SUVmax) and clinical factors with clinical outcomes was analyzed.The Kaplan-Meier method was used to calculate overall survival (OS),disease-free survival (DFS),local recurrence-free survival (LRFS),regional recurrence-free survival (RRFS),and distant metastasis-free survival (DMFS).The log-rank test was used for survival difference analysis and univariate prognostic analysis.The Cox model was used for multivariate prognostic analysis.Results The 3-year OS,DFS,LRFS,RRFS,and DMFS were 33.6％,32.1％,32.8％,31.8％,and 33.7％,respectively.The median SUVmax was 8.35 (2.7-21.5).The SUVmax of 7.0 was taken as the optimal cut-off value for all patients.Patients with SUVmax ≤7.0 had a significantly higher 3-year OS rate than those with SUVm ax ＞7.0 (42.0％ vs.28.3％,P=0.019).The univariate analysis revealed that patient age,SUV and rN were significantly associated with OS (P=0.023,0.019,and 0.002).The multivariate analysis showed that SUVmax and rN were significant influencing factors for OS,DFS,and DMFS (HR=1.68,P=0.045 and HR=2.23,P=0.003;HR=1.67,P=0.042 and HR=2.39,P=0.001;HR=1.77,P=0.025 and HR=2.40,P=0.001).Conclusions SUVmax may be one of the useful prognostic factors for OS,DFS,and DMFS in rNPC patients.