Development of a Novel Large Diamater Cryoprobe For Cavity Treatment Following Breast Cancer Tumor Resection

Cryoablation is an effective treatment for breast cancer (BC), yet its clinical use remains limited.Recent advancements, including combination therapies and its potential as an alternative to post-lumpectomy radiation, are positioning cryoablation as a key innovation in breast cancer treatment.Whether applied as a primary or adjunctive treatment, one challenge is achieving minimal lethal temperature (MLT) which results in complete cell destruction throughout the target tissue.Complicating this is the MLT varies for a given tissue/cancer type.In this study we 1) assessed cell death at various temperatures to identify the MLT for BC, assessed the impact of repetitive freeze-thaw cycles, and 2) evaluated a novel cryoprobe for post-lumpectomy cavity treatment.Cell Studies: MCF-7 cells were exposed to -10, -15, -20, or -25C for 5 minutes, followed by passive or active thawing for 5 or 10 minutes.Cell survival and modes of death were assessed over 3 days post-freeze.Minimal cell death occurred at -10C, while -25C yielded complete destruction.Single freeze cycles at -15C and -20C yielded gradual cell death, whereas repeat a freeze achieved complete destruction at -20C and near-complete death at -15C (-15C Day 1 survival: single: 20% vs. repeat: 4%).Shorter thaw intervals (5 minutes) and passive thawing enhanced ablation efficacy (-15C repeat freeze: passive: 4% survival vs. active: 29%).Cryoprobe Studies: Assessment of the novel cryoprobe revealed the ability to deliver the -20C isotherm to a depth of 1 cm within 3 minutes and the -40C isotherm within 5 minutes.These findings suggest that repeat freeze-thaw cycles and advanced cryotechnologies can optimize BC cryoablation and offer a potential as an adjunct to surgery as an alternative to post-lumpectomy radiation therapy.