AIM: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.METHODS: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.RESULTS: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).CONCLUSION: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. A investigator: 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. METHODS: 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.RESULTS: After the second course of treatment, R group in intratumor hemodynamics had 18 patients, and P group had 16 patients. 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 cours es 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) .CONCLUSION: 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.