What is the Optimal Preoperative Imaging Modality for Assessing Peritoneal Cancer Index? An Analysis From the United States HIPEC Collaborative.
Abstract Background Radiographic prediction of PCI can improve patient selection for cytoreductive surgery. We aimed to determine the correlation of CT-predicted PCI (CT-PCI) and MRI-predicted PCI (MRI-PCI) with intraoperative-PCI, and if a preoperative-PCI cutoff is associated with incomplete cytoreduction. Patients and Methods Patients from the US HIPEC Collaborative (2000-17) with appendiceal, colorectal, or peritoneal mesothelioma (PM) histology who underwent cytoreductive surgery were included. Pearson correlation coefficients were used to determine correlation between preoperative and intraoperative-PCI values. Fisher r-to-z transformation was used to compare correlations. Results 488 patients were included. 34% had non-invasive appendiceal, 30% invasive appendiceal, 28% colorectal, and 8% PM histology. CT-PCI was correlated with intraoperative-PCI for patients with non-invasive and invasive appendiceal, and colorectal histologies (r=0.689, 0.554, 0.571; all p Conclusions In this multi-institutional cohort, CT and MRI-PCI correlate well with intraoperative-PCI. MRI appears to be superior for invasive appendiceal and peritoneal mesothelioma. External validation in a larger population is needed.