ObjectiveTo determine the diagnostic value of whole-body diffusion-weighted magnetic resonance imaging (WB-DWI/MRI) to predict resectable disease at the time of secondary cytoreductive surgery for relapsed epithelial ovarian cancer with a platinum-free interval of at least 6 months.MethodsA retrospective cohort study between January 2012 and December 2021 in a tertiary referral hospital. Inclusion criteria were: (a) first recurrence of epithelial ovarian cancer; (b) platinum-free interval of ≥6 months; (c) intent to perform secondary cytoreductive surgery with complete macroscopic resection; and (d) WB-DWI/MRI was performed.Diagnostic tests of WB-DWI/MRI for predicting complete resection during secondary cytoreductive surgery are calculated as well as the progression-free and overall survival of the patients with a WB-DWI/MRI scan that showed resectable disease or not.ResultsIn total, 238 patients could be identified, of whom 123 (51.7%) underwent secondary cytoreductive surgery. WB-DWI/MRI predicted resectable disease with a sensitivity of 93.6% (95% confidence interval [CI] 87.3% to 96.9%), specificity of 93.0% (95% CI 87.3% to 96.3%), and an accuracy of 93.3% (95% CI 89.3% to 96.1%). The positive predictive value was 91.9% (95% CI 85.3% to 95.7%).Prediction of resectable disease by WB-DWI/MRI correlated with improved progression-free survival (median 19 months vs 9 months; hazard ratio [HR] for progression 0.36; 95% CI 0.26 to 0.50) and overall survival (median 75 months vs 28 months; HR for death 0.33; 95% CI 0.23 to 0.47).ConclusionWB-DWI/MRI accurately predicts resectable disease in patients with a platinum-free interval of ≥6 months at the time of secondary cytoreductive surgery and could be of complementary value to the currently used models.