Evaluation of preoperative computed tomography in estimating peritoneal cancer index in peritoneal carcinomatosis.

To evaluate the utility of CT of peritoneal carcinomatosis (PC) by comparing preoperative radiological and intraoperative peritoneal cancer index (PCI) scores. This study collected 76 patients of PC from different disease origins. The sensitivity, specificity and accuracy were calculated in each of the abdominopelvic region, and by tumor histologic type. An overall sensitivity of CT was 69%. The detection rate was highest in appendix and lowest in stomach group( 84% and 47%, respectively) by the origin of primary disease. There was a lower detection rate (59% vs 79%, p=0.001), and a higher underestimation rate (29% vs 21%, p<0.05) of small bowel lesion compared with overall abdomino-pelvic region. CT predicted an individual regional PCI score accurately in 65%, underestimated in 24%, and overestimated in 11%. CT detection rate in small tumor (<0.5 cm) was 29%, and increased to 97% with nodules size exceeding 5 cm. CT significantly underestimated the clinical PCI value in overall. The sensitivity of CT in detecting PC was influenced by histologic type, tumor location and size. CT underestimated the clinical PCI score in PC patient.