摘要
目的 探讨超声引导射频消融 (radio frequencyablation ,RFA)治疗肝肿瘤中治疗范围与射频针伞径、布针次数之间的关系 ,设计较准确的布针定点定位方法。方法 将肿瘤模式化为类球体 ,根据球体覆盖原理建立数学模型 ,应用正棱柱法及正多面体法进行推导计算 ,获得治疗范围与射频针伞径、布针次数的关系式。根据RFA治疗原则消融范围须超越肿瘤周边 0 .5cm以上 ;按照覆盖类球体肿瘤的计算结果 ,采用伞径 5 .0cm的射频针 ,治疗 4.1～ 4.3cm的肿瘤须用正四面体法至少布针 4个点 ,治疗 4.4～5 .6cm的肿瘤用正棱柱法至少布针 5～ 8个点 ,治疗 5 .7～ 6 .0cm的肿瘤用三层重叠法至少布针 12个点 ,方能达到较彻底覆盖灭活肿瘤的效果。结果 应用上述治疗方案对 32个 3.5～ 6 .6cm的病灶设计布针进行RFA治疗 ,肿瘤灭活率达 84.4%。结论 肿瘤类球体治疗计算方案对RFA治疗中不能一次覆盖的较大肿瘤 ,可提供分区布针方案 ,有助于提高RFA对肝癌的灭活率 ,减少肿瘤残留复发。
Objective To investigate the relationship among diameter of treated area,the expendable size of the ablation electrode, and number of overlapping ablations and to design the program for electrode placement by the ultrasound-guided radio-frequency ablation(RFA) of large liver tumor.Methods Two mathematical models were created for preoperative planning of the ablation in spherical tumors. The models were based on the overlapping sphere principle and were deduced and calculated by the regular prism way and regular polyhedron way. A map was achieved in detail for the optimal placement of ablation electrode. According to assumption of complete destruction of tumor and its 0.5 cm margin by 5.0 cm ablation device with this method, calculating results were obtained as follows: a tumor of 4.1 ～ 4.3 cm in diameter required 4 ablation at least by the regular tetrahedron way, a tumor of 4.4 ～ 5.6 cm in diameter required 5～8 ablation at least by the regular prism way, a tumor of 5.7 ～ 6.0 cm required 12 ablation at least by the three layers overlapping way. The treatment plan for ellipsoidal and irregular tumors were also mentioned. Results In clinic, 84.4 % of tumor which larger than 3.5 cm in diameter achieved complete ablation.Conclusions To those large tumors which were bigger than one single ablation could cover, this method can provide an effective plan of complete ablation.
出处
《中华超声影像学杂志》
CSCD
2002年第4期244-247,共4页
Chinese Journal of Ultrasonography
基金
首都医学发展科研基金项目 (ZD1 9990 9)
