Computed tomography in peritoneal surface malignancy

This chapter focuses on computed tomography (CT) in the diagnosis of peritoneal surface malignancy, mainly, pseudomyxoma peritonei, diffuse malignant peritoneal mesothelioma, high-grade gastrointestinal and ovarian peritoneal carcinomatosis, and peritoneal sarcomatosis as well as patient selection by CT for cytoreductive surgery and perioperative intraperitoneal chemotherapy. CT is the current mainstay imaging tool for patients with peritoneal surface malignancy. With administration of adequate intravenous, oral, or rectal contrast media, the high-resolution images of CT allow more precise identification and evaluation of the peritoneal disease than those provided by sonography. There are distinct patterns of cancer dissemination within the peritoneal cavity, which are dependent on the degree of invasiveness of the cancer and the tendency of mucin production. First, the histologic grade or the biologic invasiveness determines the ability of free tumor emboli to adhere and implant. Low-grade cancers generally lack capability to adhere and as a result "redistribute" widely throughout the peritoneal space. The second factor that influences the patterns of peritoneal tumor spread is the extent of mucin production. Sensitivity of CT in diagnosing peritoneal carcinomatosis varies from 60 to 90%, which is dependent on the quality of CT scans, size of tumor nodules, interpretation from a radiologist, and the abdominopelvic regions examined. The size of the peritoneal tumor is an important factor for detection on CT.