Diagnostic flow-chart to identify bowel involvement in patients with stage IIIC-IV ovarian cancer: Can laparoscopy improve the accuracy of CT scan?

Objective: This study investigates the diagnostic power of CT scan combined with exploratory laparoscopy (EXL) at identifying large bowel involvement in patients with stage IIIC-IV primary Epithelial Ovarian Cancer (EOC) by comparing with the macroscopic surgical findings at laparotomy.

Methods: All patients with FIGO Stage IIIC-IV EOC who had Visceral Peritoneal Debulking (VPD) were included in the study. Results of CT scan, EXL and laparotomy (LPT) with regards to the bowel involvement were prospectively recorded in an ad hoc study form. Setting LPT findings as the gold standard, positive and negative predictive value (PPV/NPV), sensitivity, specificity and accuracy of CT and EXL were calculated. In addition, the diagnostic power of the combination CT scan + EXL was investigated.

Results: Ninety-four out of 177 patients (53.2%) had a bowel resection during VPD. CT-scan alone had sensitivity, specificity, PPV, NPV and accuracy of 56.7%, 72.4%, 70.8%, 58.5% and 63.8% respectively. EXL alone 84.4%, 93.8%, 93.8%, 84.3%, 88.8%. CT combined with EXL detected bowel involvement with a sensitivity, specificity, PPV, NPV and accuracy of 87.5%, 70.4%, 77.8%, 82.6% and 79.6% and respectively. The combined tests showed a statistically significant improvement vs. CT scan alone (p < 0001) in sensitivity, NPV and accuracy, with non-significant difference in specificity and PPV.

Conclusions: CT-scan alone shows a limited diagnostic power at detecting large bowel involvement in patients with stage IIIC-IV EOC. The combination of CT scan with EXL increases the diagnostic power and enables to appropriately plan the bowel resection and consent the patients.