Interventional oncology and tumor ablation is a rapidly growing field of cancer therapy that may even be cost-effective for outpatient delivery of image-guided treatments of local tumors for potential cure or paliative management. A distinct benefit of cryotherapy over heat-based ablations is the excellent visualization of ice margins by CT, US and MRI. However, the 0Co visible margin is not reflective of cytotoxic tissue temperatures (e.g., <-20Co) that are needed to thoroughly cover a tumor volume. Current and emerging cryotechnologies can not measure tissue responses to freezing due to exceedingly complex responses of the cryogens during heating. In addition, variable heat-sinks around each cryoprobe prohibit accurate temperature prediction within the ice treatment zone, making current cryotherapy operator dependent, especially near major vasculature. We will demonstrate the performance of a new cryotechnology, using a single-phase liquid cooling cycle that can provide integrated thermal feedback from the cryoprobes in combination with CT-visualization. Tissue feedback of ablation response will allow determination of any adjacent vascular heat that may alter ice formation and ablation. A liquid cooling cycle will facilitate accurate measurements of this adjacent heating response, thereby characterizing local tissue conditions which will be used to quickly predict surrounding temperature distributions in conjunction with visible ice margins by computed tomography (CT). Cryotherapy can thereby be more rapidly and objectively corrected during the procedure for better outcomes and more uniform techniques use b all physicians practicing interventional oncology.
The goals of the proposal are to improve the ease-of use and reproducibility of cancer ablation outcomes by integrating thermal feedback from a new cryotechnology with computed tomography (CT) visualization of the procedure. New cryotechnology that allows immediate feedback of thermal responses by the target tissue during ablation holds great promise for both cardiac and oncologic applications. The greater complexity of planning and delivering accurate treatment profiles for thorough destruction of cancerous tumors while preserving adjacent crucial structures is the primary focus of this proposal. Parallel business activities will also explore licensing options for the newly completed single probe prototype highlighted in the Preliminary Results section since it may have immediate applications for cardiac arrhythmias and a simpler commercial path. The current proposal defines background research for potential major advances in cryotherapy treatments for cancer.
