1:30 PM Abstract No. 81 - Radiofrequency ablation following arterial injection of miriplatin-iodized-oil suspension; evaluation of ablative zone size and tissue platinum concentration in the swine liver

Abstract

Purpose To evaluate whether radiofrequency (RF) ablation following arterial injection of miriplatin-iodized-oil suspension expands ablative zone size, providing tissue platinum concentration with antitumor activity in the swine liver. Materials and Methods A total of 6 swine (mean weight, 49.3+/-1.7kg; weight range, 48.2-52.7 kg) underwent liver RF ablation. RF ablation alone was done in 2 animals (control), following arterial injection of iodized-oil (iodized-oil group) or miriplatin-iodized-oil suspension (miriplatin group) in 2 animals each. Ablative zones were created in 3 sites of each animal (total of 18 RF applications). Both the long- and short-axis diameters of ablative zones were measured. In the miriplatin group, tissue platinum concentrations were measured both in central and surrounding zones that were defined as white and red zones, respectively. Results The long- and short-axis diameters of the white zone were 27.0+/-3.1 mm and 18.0+/-0.6 mm in the control. Although significant expansion of long-axis diameter was not found in the iodized-oil group (30.2+/-2.8mm, p=0.09), it was significantly larger in the miliplatin group (33.5+/-2.4mm, p=0.02) than that in the control. The short-axis diameter was significantly expanded in the iodized-oil group (20.8+/-2.6mm, p=0.03) than that in the control, and it was significantly larger in the miriplatin group (27.2+/-1.9mm) than that in the iodized-oil group (p=0.001). Tissue platinum concentration reached effective antitumor activity levels both in white (16.5+/-5.8μg/g) and red zones (18.0+/-5.1μg/g). Conclusion RF ablation following arterial injection of miriplatin-iodized-oil suspension expands ablative zone size, providing tissue platinum concentration with antitumor activity.