Microwave ablation (MWA) has become a recommended treatment modality for interventional cancer treatment.
Compared with radiofrequency ablation (RFA), MWA provides more rapid and larger-volume tissue heating. It
allows simultaneous ablation from different entry points and allows users to change the ablation size by controlling
the power/time parameters. Ablation planning systems have been proposed in the past, mainly addressing the needs
for RFA procedures. Thus a planning system addressing MWA-specific parameters and workflows is highly
desirable to help physicians achieve better microwave ablation results. In this paper, we design and implement an
automated MWA planning system that provides precise probe locations for complete coverage of tumor and margin.
We model the thermal ablation lesion as an ellipsoidal object with three known radii varying with the duration of the
ablation and the power supplied to the probe. The search for the best ablation coverage can be seen as an iterative
optimization problem. The ablation centers are steered toward the location which minimizes both un-ablated tumor
tissue and the collateral damage caused to the healthy tissue. We assess the performance of our algorithm using
simulated lesions with known "ground truth" optimal coverage. The Mean Localization Error (MLE) between the
computed ablation center in 3D and the ground truth ablation center achieves 1.75mm (Standard deviation of the
mean (STD): 0.69mm). The Mean Radial Error (MRE) which is estimated by comparing the computed ablation radii
with the ground truth radii reaches 0.64mm (STD: 0.43mm). These preliminary results demonstrate the accuracy
and robustness of the described planning algorithm.