Validation of estimated 3D temperature maps during hepatic cryo surgery

Area of Science:

• Medical Physics
• Biomedical Engineering
• Thermal Medicine

Background:

• Cryoablation is a minimally invasive procedure used to destroy unwanted tissue.
• Accurate temperature monitoring is crucial for effective cryoablation and minimizing collateral damage.
• Existing methods for temperature estimation during cryoablation have limitations.

Purpose of the Study:

• To evaluate the accuracy of a simple model for estimating temperature distribution within the frozen region during cryoablation.
• To assess the potential of using calculated 3D temperature maps for monitoring cryotherapy.

Main Methods:

• Cryoablation experiments were performed on ex vivo and in vivo porcine livers.
• Temperature was measured using fiber-optic sensors during freezing.
• Three-dimensional MR imaging was used to obtain volumetric data post-freezing.
• A simplified bio-heat model was employed to calculate 3D temperature maps from MR image volumes.

Main Results:

• The median difference between measured and estimated temperatures was 3.03°C.
• The median distance between sensor elements and corresponding isotherms was 0.70 mm.
• The model demonstrated acceptable accuracy in temperature estimation.

Conclusions:

• The simplified bio-heat model provides accurate temperature distribution estimates during cryoablation.
• Calculated 3D temperature maps are a viable tool for monitoring cryotherapy.
• This approach can potentially improve the clinical effectiveness of cryoablation procedures.