Metabolic tumor volume on FDG-PET/CT is a possible prognostic factor for Stage i lung cancer patients treated with stereotactic body radiation therapy: A retrospective clinical study

The aim of this study was to determine whether metabolic tumor volume (mtv) and total lesion glycolysis (tlg) are associated with outcomes in stage i lung cancer patients treated with stereotactic body radiation therapy (sbrt). thirty-eight patients underwent [18f] fluorodeoxyglucose positron emission tomography/ computed tomography (18f-fdg-pet/ct) within 60 days before sbrt at our institution between january 2001 and december 2011. the maximum standardized uptake value (suvmax),mtv2,mtv4,mtv6,tlg40%,tlg50% and tlg60% were calculated. prognostic factors for overall survival (os) and local control (lc) were analyzed using cox's proportional hazards model,and survival curves were calculated using the kaplan-meier method. receiver operating characteristics (roc) curves of pet parameters for os and lc were calculated. the median follow-up period for survivors was 37.7 months. three-year os and lc rates were 56.4% and 70.5%,respectively,and 5-year os and lc rates were 36.8% and 70.5%,respectively. in univariate analyses,tumor diameter (p = 0.019),single dose ≥10 gy (p = 0.017),mtv2 (p = 0.030) and mtv4 (p = 0.048) were significant predictors for os. tumor diameter (p < 0.001),single dose ≥10 gy (p = 0.007),suvmax (p = 0.035),mtv2 (p < 0.001),mtv4 (p = 0.003),mtv6 (p = 0.017),tlg40% (p < 0.001),tlg50% (p = 0.001) and tlg60% (p = 0.003) were significant predictors for lc. suvmax was not a significant predictor for os. we made the roc curves at pet parameters,and the largest area under the curve value for os was mtv2 and for lc was tlg40%. tumor diameter,single dose ≥10 gy,mtv2 and mtv4 are prognostic factors for os and lc rates and mtv2 is a better prognostic factor for os than other pet parameters. © the author 2016.