18F-FDG PET/CT as an indicator of progression-free and overall survival in osteosarcoma.

Abstract

The aim of our study was to retrospectively evaluate whether maximum standardized uptake value (SUV(max)), total lesion glycolysis (TLG), or change therein using (18)F-FDG PET/CT performed before and after initial chemotherapy were indicators of patient outcome. Thirty-one consecutive patients who underwent (18)F-FDG PET/CT before and after chemotherapy, followed by tumor resection, were retrospectively reviewed. Univariate Cox regression was used to analyze for relationships between covariates of interest (SUV(max) before and after chemotherapy, change in SUV(max), TLG before and after chemotherapy, change in TLG, and tumor necrosis) and progression-free and overall survival. Logistic regression was used to evaluate tumor necrosis. High SUV(max) before and after chemotherapy (P = 0.008 and P = 0.009, respectively) was associated with worse progression-free survival. The cut point for SUV(max) before chemotherapy was greater than 15 g/mL* (P = 0.015), and after chemotherapy it was greater than 5 g/mL* (P = 0.006), as measured at our institution and using lean body mass. Increase in TLG after chemotherapy was associated with worse progression-free survival (P = 0.016). High SUV(max) after chemotherapy was associated with poor overall survival (P = 0.035). The cut point was above the median of 3.3 g/mL* (P = 0.043). High TLG before chemotherapy was associated with poor overall survival (P = 0.021). Good overall and progression-free survival was associated with a tumor necrosis greater than 90% (P = 0.018 and 0.08, respectively). A tumor necrosis greater than 90% was most strongly associated with a decrease in SUV(max) (P = 0.015). (18)F-FDG PET/CT can be used as a prognostic indicator for progression-free survival, overall survival, and tumor necrosis in osteosarcoma.