Accuracy of CT Scan in Predicting the Surgical PCI in Patients Undergoing Cytoreductive Surgery with/without HIPEC-a Prospective Single Institution Study.

Our aim was to study the accuracy of CT scan in predicting the peritoneal cancer index (PCI) and the impact of neoadjuvant chemotherapy (NACT), abdominal region, disease volume, and primary tumor site on it. This was a prospective single-center study that included patients undergoing cytoreductive surgery ± HIPEC. The CT-PCI was calculated and compared to the surgical PCI. The accuracy of CT-PCI in predicting the surgical PCI and the difference between the two was evaluated. From January 2018 to August 2018, 50 patients were included. The median CT PCI was 6 (range 0-35) and median surgical PCI was 17 (range 2-35). CT-PCI was more than the surgical PCI in 12 (24%), less in 23 (46%), and same in 15 (30%) with an accuracy of 30%. The highest accuracy was in region 10 and lowest in region 3. It was 15% in patients with ovarian cancer, 30% in PMP, 21% in patients receiving NACT, 35% in high-volume disease, and 42.1% in low volume disease. The CT and surgical PCI varied significantly in patients with ovarian cancer (p < 0.001), following NACT (p = 0.01) and those with moderate volume disease (p < 0.001). CT has a low accuracy in predicting the surgical PCI in both high and low volume disease. The CT-PCI can differ significantly from the surgical PCI in patients with ovarian cancer and in patients who have received NACT for peritoneal disease. The impact of NACT on accuracy of CT-PCI in non-ovarian peritoneal metastases should be evaluated further.