Pre-operative evaluation of epithelial ovarian cancer patients: Role of whole body diffusion weighted imaging MR and CT scans in the selection of patients suitable for primary debulking surgery. A single-centre study

Purpose: to evaluate the accuracy of Whole Body MRI including Diffusion-Weighted Imaging sequences (WB DWI MR) in the assessment of sites of disease in epithelial ovarian cancer (EOC), in comparison to CT; to evaluate whether a clinical-radiological score may predict suboptimal cytoreductive surgery. Methods: patients with suspected EOC who underwent pre-operative WB DWI MR were included; CT scans were recorded. Data recorded included: age, staging, dates of examinations and surgery; tumour markers; sites of disease at imaging scans and at surgery. For calculation of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of WB DWI MR and CT, surgical evaluation represented the gold standard. The accuracy of WB DWI MR and CT was compared. The association between clinical and radiological criteria with sub-optimal cytoreduction was tested to identify a final model to predict sub-optimal cytoreduction. Results: 92 patients were included; 77/92 (83.7 %) were optimally cytoreduced. Sixty-six CT and 92 MR examinations were evaluated. WB DWI MR showed overall higher accuracy than CT in assessing all sites, but it performed significantly better than CT specifically for involvement of mesentery, lumbo-aortic lymph nodes, pelvis, large bowel, sigmoid-rectum. The predicting score for suboptimal cytoreduction included: mesenteric carcinomatosis; mesenteric retraction; large bowel carcinomatosis. Conclusions: In pre-operative evaluation of EOC patients, WB DW MRI is accurate for assessment of multiple sites and it is significantly more accurate than CT for specific unresectable sites. In our series, significant sites of disease for suboptimal cytoreduction were mesenteric carcinomatosis, mesenteric retraction and large bowel carcinomatosis.