Fig. 1

Puncture pathway design. a, b and c are preoperative CT images for mapping the mass and the related structure around the mass. a is a plain CT scan. b is the arterial phase of the scan, while c is in the venous phase of the scan. After mapping the mass, an imaging marker was placed on the surface of the body (white arrows in d, denoted by a in the transverse section). Illustration of the design process for the puncture approach (light blue line, denoted by β) and calculation of the insertion site (red point, denoted by b) is shown in e. The blue line between a and b is the distance from the imaging marker (a) to the insertion site (b). β is the depth of the puncture into the tumor (red hexagon). To ensure complete ablation, a sufficient puncture depth into the mass was essential. After careful design and step-by-step insertion, the radiofrequency probe (white line) was finally placed at the planned position in the tumor (f)