Optimal approach for complete liver tumor ablation using radiofrequency ablation: a simulation study

<b>Purpose:</b> To investigate the effect of radiofrequency ablation (RFA) electrode trajectory on complete tumor ablation using computational simulation. <b>Material and methods:</b> The RFA of a spherical tumor of 2.0 cm diameter along with 0.5 cm clinical safety margin was simulated using Finite Element Analysis software. A total of 86 points inside one-eighth of the tumor volume along the axial, sagittal and coronal planes were selected as the target sites for electrode-tip placement. The angle of the electrode insertion in both craniocaudal and orbital planes ranged from −90° to +90° with 30° increment. The RFA electrode was simulated to pass through the target site at different angles in combination of both craniocaudal and orbital planes before being advanced to the edge of the tumor. <b>Results:</b> Complete tumor ablation was observed whenever the electrode-tip penetrated through the epicenter of the tumor regardless of the angles of electrode insertion in both craniocaudal and orbital planes. Complete tumor ablation can also be achieved by placing the electrode-tip at several optimal sites and angles. <b>Conclusions:</b> Identification of the tumor epicenter on the central slice of the axial images is essential to enhance the success rate of complete tumor ablation during RFA procedures.

<b>研究目的：</b> 本研究通过计算模拟方法，探究射频消融（radiofrequency ablation, RFA）电极轨迹对肿瘤完全消融效果的影响。<b>材料与方法：</b> 本研究采用有限元分析（Finite Element Analysis）软件，对直径2.0 cm的球形肿瘤及0.5 cm的临床安全边界开展射频消融模拟。在轴向、矢状及冠状平面的1/8肿瘤体积范围内，共计选取86个点位作为电极尖端的放置靶点。电极在颅尾侧平面与眶平面的插入角度范围为−90°至+90°，步长为30°。模拟过程中，射频消融电极将以颅尾侧平面与眶平面的组合角度穿过靶点，并推进至肿瘤边缘。<b>结果：</b> 当电极尖端穿透肿瘤中心点时，无论电极在颅尾侧平面与眶平面的插入角度如何，均可实现肿瘤完全消融。将电极尖端置于若干最优点位与角度时，同样可达成肿瘤完全消融。<b>结论：</b> 在轴向影像的中央层面识别肿瘤中心点，对于提升射频消融术中肿瘤完全消融的成功率至关重要。