Preoperative treatment planning as the first step in the thermal ablation process acts to lower the rate of complications, ensure tumor-free safety margins after ablation, and improve long-term survival outcomes. The procedure of application of 3D visualization navigation system in preoperative planning is as follows: first, 3D visualization images are acquired according to the CT imaging data of patients in DICOM format; second, processing and analysis of the CT images is performed, and simulated ultrasound images are acquired; third, image registration is performed; fourth, doctors perform the preoperative planning using 3D visualization preoperative treatment planning system. The planning results are completed, including the number of planning insertions, the depth of insertions, angle of needles, and so on.

Liu et al. [15] reported the clinical application of 3D visualization preoperative planning in microwave ablation in liver cancer. Ninety-four enrolled patients with liver cancer were divided into two groups. The 3D preoperative planning group included 36 patients with 44 lesions, who underwent microwave ablation with the aid of the self-developed 3D visualization navigation system. The 2-dimensional (2D) preoperative planning group included 58 patients with 64 lesions, who underwent microwave ablation according to conventional 2D image preoperative planning method. After microwave ablation, therapeutic efficacy was assessed by contrast-enhanced imaging during follow-up. Results showed that the 3D preoperative planning group has a higher successful rate of first ablation than 2D preoperative planning group (p = 0.01). The sessions are more in 2D preoperative planning group than that in 3D preoperative planning group (p = 0.002). There were no significant differences in technique effectiveness rate between the 2D preoperative planning group (96.55 %) and 3D preoperative planning group (100 %) according to the contrast-enhanced images follow-up after microwave ablation (p = 0.64). There were no significant differences in the rate of local tumor progression between the 2D preoperative planning group and 3D preoperative planning group (p = 0.64) during 3–12 months’ follow-up (median, 6 months). Compared with 2D preoperative planning group, the 3D preoperative planning group has a higher successful rate of first ablation and less number of sessions. The application of 3D visualization preoperative planning system reduced the number of sessions compared with conventional 2D imaging preoperative planning method. Less session of ablation means less risk and less cost of hospitalization and shorter hospital stay, so the application of 3D visualization preoperative planning system is beneficial to patients with liver tumors. Meanwhile, based on the results, the 3D preoperative planning improved the accuracy of the positioning and may strengthen doctors’ confidence in ablation therapy. Therefore, the 3D visualization navigation system has a relatively high clinical application value in preoperative treatment planning of microwave ablation for liver cancer (Fig. 27.2).

Intraoperative positioning is the second key step of microwave ablation for liver cancer. Precise intraoperative positioning could be realized by using the navigation techniques. The 3D visualization navigation system achieved the fusion of 2D ultrasound image and 3D visualization graphics and the display of navigation parameters interface. This system could execute the preoperative planning accurately and improve the positioning capability of beginners by using it. The 3D visualization navigation system has the advantage of commercial navigation system; in addition, 3D visualization image will provide more information for microwave ablation and enhance ablation efficacy and decrease the complication.