Abdominal and pelvic CT for detection and volume assessment of peritoneal sarcomatosis

Peritoneal sarcomatosis is a common finding in patients with recurrent abdominal or pelvic sarcoma. CT of the abdomen and pelvis is the standard radiological examination for evaluation of tumor volume and location in the peritoneal cavity; however data regarding the reliability of recurrent sarcoma detection has not been available. The purpose of this study was to evaluate the sensitivity of CT in detecting recurrent peritoneal sarcomatosis.

Abdominal and pelvic CT scans of 33 patients with abdominal or pelvic sarcoma recurrence were retrospectively reviewed. Subsequently all patients underwent surgery at which time complete exploration of the abdomen and pelvis was performed. Twenty-five CT parameters were evaluated and statistically analyzed using the findings at surgery as a standard.

Among the anatomic sites, the lesser omentum and the Douglas pouch showed a sensitivity of 100%. In the nine abdominopelvic regions sensitivity was greater than 85% in the central region, the left lower quadrant and the pelvis. In all regions and sites, the pelvis and Douglas pouch showed the highest accuracy (91%). The volume of tumor present within an abdominopelvic region influenced the sensitivity. A sensitivity of 72.5% was recorded when tumor nodules were less than 0.5 cm in diameter. This increased to 90% when tumor diameter was greater than 5 cm.

Abdominal and pelvic CT is a reliable test to evaluate recurrent sarcoma. The nodules in the pelvis were most accurately detected. Even small nodules of 0.5 cm were detected; the sensitivity increased as the nodules became greater than 5 cm.