Blood flow changes in hepatocellular carcinoma after the administration of thalidomide assessed by reperfusion kinetics during microbubble infusion -: Preliminary results

Objectives: We sought to investigate whether thalidomide is able to produce tumor vascular changes in patients with untreatable hepatocellular carcinoma (HCC) that can be detected using microbubble contrast agents. Materials and Methods: Eleven consecutive patients with untreatable HCC underwent contrast-enhanced ultrasound before and during thalidomide administration. Real-time destruction reperfusion kinetics was obtained from a representative HCC nodule and from the surrounding liver parenchyma during SonoVue infusion (Bracco, Milan, Italy) at a constant rate of 0.10 mL/s by using a syringe pump and modelized according to the mathematical function SI = A(1 exp(-beta t)) where the plateau signal intensity A reflects the percent blood volume, the time constant beta reflects the average speed of blood, and their product A*beta reflects the nutrient blood flow. Results: Size of the representative nodule reduced significantly 3 to 6 months after the start of thalidomide treatment. Before thalidomide administration A, P, and A*P of the index lesion were 44 +/- 60 LIU, 0.31 +/- 0.40 seconds' and 8.1 +/- 11.8 LIU/s, respectively). A and A*P reduced significantly after 15 days (26 +/- 50 LIU and 2.9 +/- 4.8 LIU/s, P < 0.01), 3 months (12 +/- 18 LIU, and 4.3 +/- 7.7 LIU/s, P < 0.01), and 6 months (13 +/- 23 LIU and 2.4 +/- 3.7 LIU/s, P < 0.05) of treatment. No statistically significant changes of the exponential time constant beta were observed, nor changes of A, beta and A*P in the liver parenchyma. Conclusions: Contrast-enhanced ultrasound can be used effectively to evaluate changes in perfusion parameters of HCC nodules during thalidomide administration.