Survival Benefit of Radiofrequency Ablation with Intratumoral Cisplatin Administration in a Rabbit VX2 Lung Tumor Model.

PURPOSE: This study evaluated the survival benefit of a combination therapy with radiofrequency ablation (RFA) and intratumoral cisplatin (ITC) administration for lung tumors by using a rabbit VX2 tumor model. MATERIALS AND METHODS: Experiments were approved by the institutional animal care committee. VX2 tumor suspension was injected into the lungs of Japanese white rabbits under CT guidance to create a lung tumor model. Thirty-two rabbits bearing a transplanted VX2 lung tumor were randomly assigned to four groups of eight: control (untreated); RFA alone; ITC alone; and RFA with ITC. All treatments were performed one week after tumor transplantation. Kaplan-Meier survival curves were compared by the log-rank test. RESULTS: The median survival time was 24.5 days (range 17-33 days) in the control group, 40 days (30-80 days) in the RFA alone group, 31.0 days (24-80 days) in the ITC alone group, and not reached (53-80 days) in the RFA with ITC group. The median survival was significantly longer with the RFA/ITC combination compared to the control group (P < 0.001), RFA alone (P = 0.034), and ITC alone (P = 0.004). The survival time after RFA alone was also significantly longer than that of the control group (P < 0.001). There was no significant difference in tumor size or the rate of pneumothorax between each group. CONCLUSION: RFA prolonged the survival of rabbits with lung VX2 tumors when combined with ITC.