Usefulness of contrast-enhanced ultrasonography in determining treatment efficacy and outcome after pancreatic cancer chemotherapy

Abstract

To investigate if contrast-enhanced ultrasonography (CE-US) is useful for determining treatment efficacy and outcome in the early stages of pancreatic cancer chemotherapy by assessing changes in intratumor hemodynamics using CE-US with a contrast agent. The subjects were 34 patients with unresectable advanced pancreatic cancer treated by chemotherapy. CE-US was assessed after every treatment (course) completion under the same conditions, and patients were divided into two groups according to the intratumor enhancement pattern: Vascular rich (R) group and vascular poor (P) group. After the second course of treatment, R group in intratumor hemodynamics had 18 patients, and P group had 16 patients. The reduction rates of serum CA19-9 level after chemotherapy which decreased to half or less of the baseline level were 2/15 (0.1%) in P group, but 11/16 (69%) in R group (P = 0.006). When the mean number of courses of chemotherapy and outcome were compared, P group had a mean number of courses of 4.9 (R group, 10.2) and mean survival time (MST) of 246 d (R group, 402 d), showing that outcome was significantly better in R group (P = 0.006). CE-US revealed that the change in intratumor blood flow correlated with both serum CA19-9 level and outcome. Patients with serum CA19-9 that decreased to less than half the baseline level, and patients with an abundant intratumor blood flow, had a significantly better outcome. Thus, CE-US is potentially useful for evaluating treatment efficacy and outcome in the early stages of pancreatic cancer chemotherapy.