Assessment of Cryosurgical Device Performance Using a 3D Tissue-Engineered Cancer Model

Area of Science:

• Oncology
• Biomedical Engineering
• Medical Physics

Background:

• Cryoablation is increasingly used for cancer treatment, necessitating better understanding of the frozen mass dynamics.
• Current methods using phantom models lack accuracy in simulating real tissue heat loads and ablative effects.
• Accurate characterization of iceball size, critical isotherms, and lethal zones is crucial for effective cryoablation.

Purpose of the Study:

• To evaluate a tissue-engineered tumor model (TEM) for assessing cryoprobe performance.
• To compare TEMs with traditional phantom models in simulating cryoablation conditions.
• To analyze iceball size, thermal profiles, and the resultant ablative zone in a TEM.

Main Methods:

• Utilized an Endocare V-probe cryoprobe with a double freeze-thaw protocol on prostate and renal cancer TEMs.
• Measured iceball size and temperature distribution within the TEM.
• Assessed the ablative zone using fluorescence microscopy 24 hours post-thaw.

Main Results:

• Generated a 33-38 cm³ frozen mass, with 12.7 cm³ at or below -20°C and 6.5 cm³ at or below -40°C.
• Observed complete ablation in the inner 40% of the frozen mass, with partial to minimal destruction in the outer 1 cm periphery.
• TEM results correlated well with clinical outcomes in renal and prostate cancer cryoablation.

Conclusions:

• Tissue-engineered models provide a more comprehensive characterization of cryoablation device performance than phantom models.
• TEMs better simulate in vivo conditions, including external heat load and cellular components, for evaluating critical isotherm penetration.
• This improved modeling enhances understanding of cryoprobe performance and its impact on ablative outcome in cancer treatment.