CORRELATION BETWEEN RADIOLOGICAL (PCIR) AND SURGICAL (PCIS) PERITONEAL CARCINOMATOSIS INDEX (PCI)

Abstract

Abstract Introduction The Peritoneal Carcinomatosis Index (PCI) is used for the selection of candidates for cytoreductive surgery (CRS)+HIPEC and as a prognostic for resectability. The accuracy of MDCT (Multidetector Computed Tomography) is evaluated by analyzing the degree of correlation between preoperative PCIr and surgical PCIs. Methods We conducted an observational, longitudinal, single-center and retrospective study between May 2014 and 2018 on patients operated upon for peritoneal carcinomatosis. Preoperative TCDM were interpreted by an expert radiologist and PCIs were calculated intraoperatively. Comparison was performed using the Concordance Correlation Coefficient (CCC). The Bland-Altman method was used to represent the difference between observations, with a 95% confidence interval (CI). The sensitivity and specificity of PCIr <20 as a predictor of resectability was also assessed. Results Mean PCIs of the 50 patients undergoing CRS+HIPEC was 11.8 (9.5), and mean PCIr was 11.0 (10.1). The CCC between both was 0.94 (95% CI 0.91–0.97). Sensitivity of PCIr was 0.82 (95%CI 0.68–0.92), being resectable 37/40 patients with PCIr <20. Specificity of PCIr fell to 0.40 (95%CI 0.05–0.85), by failing to achieve complete cytoreduction in 2/10 patients with PCIr ≥20. Positive predictive value was 0.92 (95%CI 0.80–0.98), and negative predictive value was 0.20 (95%CI 0.03–0.56). Conclusions MDCT interpreted by an expert radiologist is an indispensable tool for the selection of patients who are candidates for CRS+HIPEC. A PCIr ≥20 is not synonymous with unresectability.