Cryoablation is a minimally invasive and efficient therapy option for liver cancer. Liquid nitrogen was used to kill the unwanted cells via freezing. One of the challenges of cryosurgery is to destroy the complete tumor without damaging the surrounding healthy cells when the tumor is large. To overcome this challenge, multi-cryoprobes were arranged in a polygonal pattern to create a uniform cooling and optimum ablation zone in the tissue. Single, three, and four cryoprobes were placed in the center, triangle, and square patterns to analyze the temperature profile and ablation zone. The results showed that tissue will freeze quickly when cryoprobes are placed in a square pattern. After the treatment of 600 seconds, $99\%$, $96\%$, and $31\%$ of the tumor were killed using four, three, and single cryoprobes, respectively. One of the difficulties in the multi-probe technique is choosing the probe separation distance and cooling time. The volume of the ablation zone, the thermal damage to healthy cells, and the volume of tumor cells killed during the treatment for different probe separation distances of 10 mm, 15 mm, and 20 mm are analyzed. Compared to other settings, a multi-probe technique destroys the entire tumor with the least harm to healthy cells when probes are arranged in a square pattern with a 15 mm space between them.

翻译：冷冻消融是一种微创且有效的肝癌治疗选择。通过使用液氮冷冻来杀死异常细胞。冷冻手术面临的挑战之一是在肿瘤较大时，如何完全摧毁肿瘤而不损伤周围健康细胞。为克服这一挑战，将多根冷冻探针按多边形图案排列，在组织中形成均匀冷却和最佳消融区域。将单根、三根和四根冷冻探针分别置于中心、三角形和正方形图案中，分析温度分布和消融区域。结果表明，当探针按正方形图案放置时，组织会更快冻结。经过600秒治疗，使用四根、三根和单根冷冻探针分别杀死了99%、96%和31%的肿瘤。多探针技术的一个难点在于选择探针间距和冷却时间。分析了在探针间距分别为10毫米、15毫米和20毫米时，消融区域体积、对健康细胞的热损伤以及治疗期间杀死的肿瘤细胞体积。与其他设置相比，当探针以15毫米间距按正方形图案排列时，多探针技术在最小损伤健康细胞的情况下完全摧毁了肿瘤。