Chemo-embolization for unresectable hepatocellular carcinoma with different sizes of embolization particles

The purpose of this study was to evaluate the size responses and vascular responses to three different sizes of Embosphere (EMBS) embolization particles used for chemo-embolization in patients with unresectable hepatocellular carcinoma (HCC). Forty-seven patients with biopsy proven HCC treated with TACE using EMBS (Biosphere Medical, Rockland, MA, USA) were included in this study. EMBS are non-resorbable tris-acryl gelatin defined-size microspheres. Sixteen patients were treated with 40-120 micron (40-mu m), 13 patients with 100-300 (100-mu m), and 18 patients with 300-500 (300-mu m) EMBS particles. We measured the two-dimensional area and vascularity of the tumor index lesion on initial and subsequent CTs after treatment. Lesions were classified into four grades based on the degree of vascularity measured in 25% increments. Size of tumor after one treatment decreased by an average (avg) of 18% for 40-120-mu m particles, 38% for 100-300-mu m particles, and 17% for 300-500-mu m particles. After three treatments, size decreased by an avg of 46% for 40-120-mu m particles, 76% for 100-300-mu m particles, and 46% for 300-500-mu m particles. Vascularity decrease was also measured after the first and third treatments, and defined as a decrease of one or more grades in tumor vascularity. Results were as follows (% of patients with decrease). For 40-120-mu m particles: 1 and 3 treatments, 53% and 88% of patients. For 100-300-mu m particles: 1 and 3 treatments, 60% and 88% of patients. For 300-500-mu m particles: 1 and 3 treatments, 50% and 57% of patients. It was concluded the 100-300-mu m EMBS particles produce slightly higher responses.