Prognostic value of 18F-FDG PET/CT in postoperative recurrence of retroperitoneal liposarcoma: a single-center retrospective study

Abstract

Objective Recurrence is the leading cause of tumor-related death in retroperitoneal liposarcoma (RPLPS). Variant subtypes of RPLPS determine different recurrence 18F]-fluoro-2-deoxy-D-glucose (18F-FDG) PET/computed tomography (PET/CT). This study analyzed the characteristics of different histologic subtypes of 18F-FDG PET/CT and their associations with recurrence and prognosis. Methods Clinical-pathological information, 18F-FDG PET/CT data, recurrence, and progression-free survivals (PFS) of 83 patients with RPLPS were collected. Maximum and peak standardized uptake values (SUVmax and SUVpeak, respectively) and mean CT value (CTmean) of tumors were measured and correlated with histologic subtype. Receiver operating characteristics (ROC) curves were used to analyze the predictability for subtype and recurrence. Kaplan-Meier analysis examined SUVmax and SUVpeak as recurrence risk factors. Results Studied patients with different types of liposarcomas. Dedifferentiated liposarcomas (DDLPS) had higher SUVmax and SUVpeak than well-differentiated (WDLPS) and myxoid/round cell (MLPS) types. WDLPS had lower CTmean values compared to MLPS and DDLPS. Using ROC curves, determined cut-off values for SUVmax (5.1) to differentiate DDLPS, SUVpeak (3.0) for WDLPS, and CTmean (12.3 Hu) for WDLPS. These cut-offs were found to be best for predicting recurrence. Kaplan–Meier analysis showed that histologic subtype, SUVmax, and SUVpeak were all linked to recurrence-free survival. Conclusions The use of SUV and CT features on 18F-FDG PET/CT imaging may increase confidence in subtype diagnosis. Patients with SUVmax > 5.1 or SUVpeak > 3.0 suggest a poor prognosis.