Introducing and Comparing Three Software Tools for Ablation Zone Quantification in Thyroid Radiofrequency Ablation Models

Ziel/Aim The present work aims to assess three software-based methods for digital detection and planimetry of ablation zones in thyroid radiofrequency ablation (RFA). Special emphasis was laid on accurately quantifying ablation zone shrinkage resulting from perfusion (heat sink effect).

Methodik/Methods Digital planimetry is a method that allows the experimental study of RFA success and its limitations. Developing and validating a streamlined process for planimetric analysis is a prerequisite for further extraction of useful feature sets which contain significant discriminatory information. The first solution is an Excel-based script that converts the ablation zone contour into a diagram by mathematical approximation. The two other alternatives are Python-based utilizing functions for preprocessing, computer vision and pixel-based calculation. One relies on computer vision for contouring derived from a region of interest (ROI) within the ablation zone, while the other incorporates manual contouring to build a polygon along the ablation zone border. All relevant geometric parameters are then calculated, including maximal and minimal radius, ablation zone area, zone distribution around the ablation center and heat sink ratio.

Ergebnisse/Results Three individual software codes were built to analyze ablation zones. Each tool enabled calculation of distinguishing parameters and yielded consistent results in comparison. Focusing on reproducibility and accuracy in thyroid tissue, the proposed Python-based approach with manual contouring was favored for further studies.

Schlussfolgerungen/Conclusions A Python-based program for digital planimetry has been successfully developed and validated. It proved to be a reliable tool for ablation zone analysis in terms of accuracy and documentation of relevant parameters in thyroid RFA. The software code is under further development to extend functionality and fields of future application.

Publication History

Article published online:
08 April 2021