Abstract No. 561 Systematic Performance Characterization of Cryoprobes used in Interventional Oncology Procedures

Cryoablation systems offer flexibility to adjust both freezing and thawing functions; however, vendors provide performance data across a single (freeze only) operation mode. Here, we developed a robust, 3D-printed phantom set-up that enables repeatable cryoprobe performance measurements across experimental variables and used it to investigate the effect of different modes of cryoprobe operation on iceball size, thermal gradients and thaw rates. Two IceFORCE cryoprobes were positioned 2 cm apart and inserted into a tissue mimicking gel phantom1 at room temperature (∼21°C). Ten-minute freeze cycles were performed at 25, 50, and 100% freeze settings. The experimental setup was brought back to the original conditions between experiments. Using 8 fiber optic sensors, temperatures were sampled throughout the volume every 1s. Two sensors were positioned 1 and 4 mm off the cryoprobe tip and 6 sensors were positioned at systematic locations between the two cryoprobes. CT images were acquired at 20s intervals to track iceball size and confirm sensor position. Thermal gradients and maximum potentially lethal zones (defined as T2 min). Cryoablation vendors provide options to tailor ablation parameters to better meet treatment requirements and sculpt the ice to avoid sensitive organs. Our investigation demonstrated that using a low freezing rate setting does not result in lethal temperatures in the center of the treatment zone created by 2 probes positioned 2 cm apart, despite generating a sizeable iceball (38×20 mm, midplane).