Explorative Study on the Predictive and Prognostic Value of Early Complete Metabolic Response By FDG-PET–CT During Neoadjuvant Chemotherapy in Patients With Advanced Ovarian Cancer

Background and AimEarly complete metabolic response (e-CMR) by fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) during neoadjuvant chemotherapy (NACT) in advanced ovarian cancer (AOC) could have predictive and prognostic value. The present explorative study prospectively investigated changes of dual-time FDG-PET, at baseline and after 3 cycles of NACT in patients who were not candidates for upfront debulking surgery by comparing with standard serum cancer antigen 125 (CA-125) monitoring.Patients and MethodsFifty consecutive patients with AOC were treated with 6 cycles of carboplatin/paclitaxel before surgery. FDG-PET and serum CA-125 were evaluated at baseline and after 3 cycles. e-CMR and early complete biochemical response (e-CBR) were defined as the normalization of the maximum standardized uptake values and serum CA-125 levels, respectively.Resultse-CMR and e-CBR were observed in 34% and 38% of patients, respectively. At the end of NACT, an optimal pathologic response (pR) and optimal surgery with no residual tumor (R0) were achieved in 23 (46%) and 26 (52%) patients, respectively. E-CMR and e-CBR positive predictive value was 88% and 84% for pR and 88% and 89% for R0, respectively. After a median follow-up of 42 months, 41 (82%) patients had progressed and 32 (64%) died. Median progression-free survival and overall survival were 13.8 and 28.1 months, respectively. At multivariate analysis, e-CMR, but not e-CBR, showed an independent prognostic value with regard to both progression-free survival and overall survival.Conclusionse-CMR may predict pR and R0 surgery obtained at the end of NACT and identify patients a favorable long-term outcome.