Using Patient-Specific 3D Modeling and Simulations to Optimize Microwave Ablation Therapy for Liver Cancer

Abstract

Microwave ablation (MWA) of liver tumors presents challenges like under- and over-ablation, potentially leading to inadequate tumor destruction and damage to healthy tissue. This study aims to develop personalized three-dimensional (3D) models to simulate MWA for liver tumors, incorporating patient-specific characteristics. The primary objective is to validate the predicted ablation zones compared to clinical outcomes, offering insights into MWA before therapy to facilitate accurate treatment planning. Contrast-enhanced CT images from three patients were used to create 3D models. The simulations used coupled electromagnetic wave propagation and bioheat transfer to estimate the temperature distribution, predicting tumor destruction and ablation margins. The findings indicate that prolonged ablation does not significantly improve tumor destruction once an adequate margin is achieved, although it increases tissue damage. There was a substantial overlap between the clinical ablation zones and the predicted ablation zones. For patient 1, the Dice score was 0.73, indicating high accuracy, with a sensitivity of 0.72 and a specificity of 0.76. For patient 2, the Dice score was 0.86, with a sensitivity of 0.79 and a specificity of 0.96. For patient 3, the Dice score was 0.8, with a sensitivity of 0.85 and a specificity of 0.74. Patient-specific 3D models demonstrate potential in accurately predicting ablation zones and optimizing MWA treatment strategies.

Keywords: 3D model; ablation zone; finite element method; image-guided cancer therapy; liver cancer; microwave ablation; necrotic tissue; thermal ablation.

Figure 1

(A) Surface segmentation of the liver, tumor, and blood vessels for patient 1. (B) All components were modified and converted to 3D solid volume models. (C) The patient-specific 3D model was created (top), and the appropriate mesh volume was applied to the model (middle). The mesh test was applied to control the mesh quality, and the mesh size was modified accordingly (bottom).

Figure 2

Microwave antenna insertion in patients. This figure illustrates the positioning of the microwave antenna for microwave ablation treatments in three different patients: (A) patient 1, (B) patient 2, and (C) patient 3.

Figure 3

Comparative analyses of tumor destruction (left) and liver tissue damage (right) over a standard ablation time of 10 min for patient 1 (P1; blue dotted line), patient 2 (P2; red dashed line), and patient 3 (P3; green dashed line).

Figure 4

Temperature distribution in the tumor (left; color bars indicate temperatures in degrees Celsius) and liver damage fraction (right; ablation volume captures regions where the Arrhenius value ${\theta }_d$ > 0.98) for patient 1 (A), patient 2 (B), and patient 3 (C). For each patient, the coronal view (top) and sagittal view (bottom) are shown.

Figure 5

Patient-specific 3D models for patient 1 (A), patient 2 (B), and patient 3 (C). In each panel, the first image from the left shows the liver, tumor, and blood vessels, and the second image shows the clinical ablation zone (blue), computational ablation zone (orange), and tumor (green). The third and fourth images are post-ablation CT images showing the liver (blue), tumor (green), 5 mm MAM (yellow), clinical ablation zone (orange), and predicted ablation zone (purple) for ablation times of 10 min and 9.5 min, respectively.