Prognostic value of metabolic parameters determined by preoperative 18F-FDG PET/CT in patients with uterine carcinosarcoma

Objective: To evaluate the prognostic value of metabolic parameters measured by preoperative F-18-fluorodeoxyglucose (F-18-FDG) positron emission tomography (PET)/computed tomography (CT) in patients with uterine carcinosarcoma (UCS). Methods: Data of 55 eligible patients with UCS who underwent preoperative F-18-FDG PET/CT and surgical staging were analyzed retrospectively. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV2.5), and total lesion glycolysis (TLG(2.5)) of the primary tumors were measured using a SUV threshold of 2.5. The optimal cutoff value of each parameter was determined by time-dependent receiver operating characteristic curve, and its impact on progression-free survival and overall survival was evaluated by Cox proportional hazards model. Results: During a median follow-up period of 29 (range, 1.5-109.4) months, 47.3% (26/55) of the patients experienced disease progression, and the disease-associated mortality rate was 43.6% (24/55). Univariate analysis determined that hazard ratios (HRs) for disease progression for SUVmax (>= 8.33), MTV2.5 (>= 63.92 mL), and TLG2.5 (>= 396.16) were 1.930 (95% confidence interval [CI]=0.793-4.701), 3.264 (95% CI=1.466-7.268), and 2.692 (95% CI=1.224-5.924), respectively. And, HRs for death were 1.979 (95% CI=0.774-5.060), 2.764 (95% CI=1.217-6.274), and 2.721 (95% CI=1.198-6.182), respectively. While peritoneal cytology, histology, and tumor diameter were independent prognostic factors in multivariate analysis, MTV and TLG were not. Conclusion: Though MTV and TLG of primary UCS were not independent predictors compared to surgically obtained data, MTV and TLG of primary UCS may provide useful information on prognosis especially in patients who are not able to undergo surgical staging.