Abdominal computed tomographic scan in the selection of patients with mucinous peritoneal carcinomatosis for cytoreductive surgery.

BACKGROUND

Cytoreductive surgery and intraperitoneal chemotherapy have been used to treat peritoneal carcinomatosis. A complete surgical resection is required for optimal results to be achieved. This study evaluated the preoperative computed tomographic (CT) findings in patients with mucinous peritoneal carcinomatosis in order to predict the probability of a complete resection.

STUDY DESIGN

Computed tomographic scans of the abdomen and pelvis were reviewed retrospectively in 45 patients with a diagnosis of mucinous peritoneal carcinomatosis who were treated with surgery and intraperitoneal chemotherapy. According to the completeness of cytoreduction, patients were divided into two groups. Patients in the first group (n = 25) had complete cytoreduction (CR) with no tumor deposits 2.5 mm in diameter or larger left behind. The surgical resection of tumor was incomplete in the second group of patients (n = 20). Sixteen CT parameters were initially examined in each group of patients and statistically evaluated according to the completeness of the cytoreductive surgical procedure.

RESULTS

The incidences of six CT findings were significantly different in the two groups of patients. These findings were: tumor volume in small bowel mesentery (p < 0.001), tumor volume in proximal jejunum (p = 0.003), tumor volume in distal jejunum (p = 0.002), tumor volume in proximal ileum (p = 0.003), mesentery configuration (p < 0.001), and obstruction of bowel segments by tumor (p < 0.001). A statistical approach using a tree-structured diagram showed that patients with both obstruction of bowel segments by tumor and tumor diameter greater than 0.5 cm on small bowel surfaces exclusive of distal ileum on preoperative CT scan, had an 88 percent probability of incomplete resection. Patients without these two CT findings had a 92 percent probability of complete resection.

CONCLUSIONS

This study shows that selection criteria for patients with mucinous peritoneal carcinomatosis are available on a preoperative CT scan of the abdomen and pelvis. Patients whose scans show obstruction of bowel segments by tumor and tumor diameter greater than 0.5 cm on small bowel surfaces exclusive of distal ileum are unlikely to be candidates for cytoreductive surgery for the treatment of peritoneal carcinomatosis.