Evaluation of computed tomography in patients with peritoneal carcinomatosis

Radiologic tests to determine the size and location of cancer on peritoneal surfaces are needed for patient management and for clinical research activity.

Computed tomography (CT) of the abdomen and pelvis were obtained on 45 patients with a diagnosis of peritoneal carcinomatosis before implementation of a complete exploratory laparotomy with biopsy or resection of all tissues suspicious of malignancy. CT findings and surgical findings were recorded and the data analyzed by dividing the abdomen into 9 regions or into 15 anatomic sites.

In an overall patient analysis, the sensitivity was 79%. In the nine different abdominal regions, sensitivity was greater than 80% in the right flank, left flank, and right lower and left lower abdominal regions. Sensitivity was lowest in the pelvis (60%). Negative predictive value in the pelvis was 20%. The volume of tumor present within an abdominal region or anatomic site greatly influenced the sensitivity. A sensitivity of only 28% was recorded when tumor nodules were less than 0.5 cm in thickness. This increased to 90% when nodule thickness was greater than 5 cm.

CT is not a reliable diagnostic test for low volume tumor on peritoneal surfaces, and the greatest inaccuracies were recorded in the pelvis. Its diagnostic value increased as tumor volume increased.