Quantitative measurement of blood flow using perfusion CT for assessing clinicopathologic features and prognosis in patients with rectal cancer.

Abstract

The ability to evaluate clinicopathologic features and prognosis before surgery by contrast-enhanced CT would be valuable for managing rectal cancer. This study was designed to evaluate the clinical usefulness of perfusion CT in patients with rectal cancer before surgery. Forty-four consecutive patients (27 men, 17 women; median age, 63.6 years) with rectal cancer underwent perfusion CT before surgery. We retrospectively investigated the correlations between tumor blood flow generated by perfusion CT and clinicopathologic features. There was a significant correlation between blood flow and wall invasion (P = 0.04). Well-differentiated tumors showed significantly higher blood flow than moderately differentiated tumors (P = 0.03). There was a significant tendency for tumors with low blood flow to show lymph node metastasis (P = 0.0005), vascular invasion (P = 0.004), lymphatic invasion (P = 0.04), and distant metastasis (P = 0.0005). For blood flow, accuracy was 75% for detection of tumors with lymph node metastasis if the cutoff point was set at 55 ml/100 g per minute. Patients with high blood flow tumors survived significantly longer than those with low blood flow tumors (P = 0.002). Blood flow of rectal cancers may be useful to evaluate pathologic features and prognosis before surgery.