Effects of the type of embolization particles on carboplatin concentration in liver tumors after transcatheter arterial chemoembolization in a rabbit model of liver cancer

PURPOSE: To study the effect of particle type used during transarterial hepatic chemoembolization (TACE) on carboplatin concentration after TACE in an animal model of liver cancer (VX2) and to determine the concentration of carboplatin within tumor, liver, and plasma. MATERIALS AND METHODS: The VX2 tumors were grown in the livers of 23 rabbits. Carboplatin (5 mg/kg) was selected because of its known potency against VX2 tumor. Group I was treated with TACE with tris-acryl gelatin microspheres (100-300 mu m), group 2 was treated with TACE with polyvinyl alcohol (PVA; 150-250 mu m), group 3 (control) was treated with intraarterial saline solution, and group 4 (pharmacokinetic) was treated with intraarterial carboplatin. Animals were killed after 48 hours, and concentrations of carboplatin were measured by atomic absorption spectroscopy from samples of blood and liver (central and peripheral zones of tumor and nontumorous liver tissue). RESULTS: In group 1 (tris-acryl gelatin microspheres) and group 2 (PVA), the mean carboplatin concentrations were 117 mu g/g and 31.8 mu g/g, respectively, within the central zone of the tumor and 38.5 mu g/g versus 7.9 mu g/g, respectively, in the peripheral zone. No carboplatin was detected in nontumorous liver tissue and plasma concentrations were low in both treated groups (< 0.079 mu g/mL). CONCLUSIONS: Carboplatin concentration was significantly greater (by a factor of two to four) within the central zone of the tumor compared with the peripheral zone in both treated groups. The overall tumor carboplatin concentrations were significantly greater in the tris-acryl gelatin microsphere group than in the PVA group (P <.001), which could translate into greater potency and tumor kill. Administration of tris-acryl gelatin microspheres may be clinically advantageous during TACE, as it contributed to greater delivery of chemotherapy to tumor in the present study.