Accuracy of radiologic- laparoscopic peritoneal carcinomatosis categorization in the prediction of surgical outcome.

objectiveTo evaluate the agreement between multiple detector CT (MDCT) and laparoscopy in the preoperative categorization of peritoneal carcinomatosis, and to determine the impact of this categorization on the prediction of cytoreduction status.

methodsThis prospective study included 80 consecutive females with primary ovarian cancer eligible for cytoreductive surgery (CRS). MDCT and diagnostic laparoscopy were performed prior to surgery for assessment of peritoneal carcinomatosis extent. Based on PCI (peritoneal cancer index) score, carcinomatosis was categorized into three groups. Categorization agreement between CT and laparoscopy was assessed and compared with the intraoperative-histopathologically proven PCI. Impact of PCI categorization on cytoreduction status was also evaluated.

resultsThe overall agreement between CT and laparoscopy in preoperative peritoneal carcinomatosis categorization was good (K =0.71-0.79) in low category group and excellent in both moderate and large group (interclass correlation coeeficient = 0.89-0.91). (p<0.01) Optimal cytoreduction was achieved in 62/80 (77.5%) patients, PCI < 20 was detected in 48/62 (77.4%), pre-operative PCI < 20 correctly predicted optimal cytoreductive surgery (OCS) in 40/48 (83.3%) cases. Suboptimal cytoreduction was performed in 18/80 (22.5%) patients. PCI > 20 was detected in (10/18) 55.6%, preoperative CT and laparoscopy PCI > 20 correctly predicted SCS in 8/10 (80%) cases. The area under receiver operating characteristic curve showed that PCI cut-off <20 was the best predictor of OCS with an accuracy 85%, sensitivity 97%, specificity 40%, negative predictive value 76%, and positive predictive value 93%.

conclusionBoth laparoscopy and CT are equally effective in pre-operative peritoneal carcinomatosis categorization. PCI < 20 is accurate in the prediction of optimal cytoreduction. More than half of patients with suboptimal cytoreduction had PCI > 20 and interval debulking surgery can be recommended. ADVANCES IN KNOWLEDGE: Both laparoscopy and CT are equally effective in pre-operative peritoneal carcinomatosis categorization. PCI < 20 is accurate in the prediction of optimal cytoreduction. More than half of patients with suboptimal cytoreduction had PCI > 20 and interval debulking surgery can be recommended.