MRI with diffusion-weighted imaging to predict feasibility of complete cytoreduction with the peritoneal cancer index (PCI) in advanced stage ovarian cancer patients.

OBJECTIVES

To determine the diagnostic performance of MRI with diffusion-weighted imaging (DW-MRI) in assessing the peritoneal tumor load and predicting whether a complete cytoreduction can be achieved in patients with epithelial ovarian cancer (EOC).

METHODS

For this observational prospective study, 25 patients with epithelial ovarian cancer scheduled for cytoreductive surgery were included. Patients underwent a 3 T DW-MRI scan prior to surgery. The MR protocol consisted of a T1 and T2 weighted, a contrast-enhanced T1 weighted, and a diffusion-weighted (b0, b1000) sequence. The Peritoneal Cancer Index (PCI) was determined on DW-MR images (MRI-PCI) by two readers, independently, and was compared to the PCI determined during surgery (S-PCI). The inter-observer agreement between the two radiologists was evaluated. In addition, receiver operating characteristics curves were calculated for predicting complete cytoreduction with the S-PCI and MRI-PCI.

RESULTS

Staging with DW-MRI showed a correlation to surgical staging with an intraclass correlation coefficient (ICC) 0.86 and 0.85 for reader 1 and 2, respectively. Inter-observer agreement was excellent with an ICC of 0.90 (95% CI: 0.64-0.96). The MRI-PCI scores of reader 1 (AUC = 0.96), reader 2 (AUC = 0.98), and the S-PCI (AUC = 0.92) showed similar predictive values for complete cytoreduction.

CONCLUSION

DW-MRI is accurate in predicting the S-PCI and can be helpful to predict whether a complete resection in ovarian cancer patients is feasible.