Multiparametric PET/MR (PET and MR-IVIM) for the evaluation of early treatment response and prediction of tumor recurrence in patients with locally advanced cervical cancer

Objectives To assess the value of 18 F-FDG PET and MR-IVIM parameters before and during concurrent chemoradiotherapy (CCRT) for evaluating early treatment response and predicting tumor recurrence in patients with locally advanced cervical cancer (LACC) using a hybrid PET/MR scanner. Methods Fifty-one patients with LACC underwent pelvic PET/MR scans with an IVIM sequence at two time-points (pretreatment [pre] and midtreatment [mid]). Pre- and mid-PET parameters (SUV max , MTV, TLG) and IVIM parameters ( D , F , D *) and their percentage changes (Δ%SUV max , Δ%MTV, Δ%TLG, Δ% D , Δ% F , Δ% D *) were calculated. We selected independent imaging parameters and built a combined prediction model incorporating imaging parameters and clinicopathological risk factors. The performance of the combinative evaluation for tumor early shrinkage rates (TESR) and the prediction model for tumor recurrence was assessed. Results Thirty-two patients were classified into the good response (GR) group with TESR ≥ 50%, and 19 patients were categorized into the poor response (PR) group with TESR