首次低剂量超声辐照对HIFU消融兔肝VX2瘤的影响

Effect of firstly low-dose ultrasound irradiation on ablation of rabbit liver VX2 tumor with high intensity focus ultrasound therapy

目的探讨首次辐照不同低剂量的超声对HIFU消融兔肝VX2瘤的影响。方法 45只荷瘤兔按随机数字表法分为3组:A组首次辐照功率为0W,B组80W,C组100W;均于第2天接受声功率为180W的消融治疗。结果产生相同的凝固性坏死体积B组所用的时间较A组少(P<0.05);B组与C组达到消融坏死的时间无明显差异,但C组所产生的凝固性坏死体积更大(P<0.05);3组比较,A组的能效因子(energy efficiency factor,EEF)值(46.43±13.67)最大,C组最小(7.01±1.33,P<0.05)。结论首次低剂量辐照的功率越大,增效作用越明显。

Objective To investigate the effect of ultrasound irradiation at different low doses on the curative effect of high intensity focus ultrasound（HIFU） on rabbit VX2 liver tumor.Methods Forty-five rabbits bearing VX2 tumors at a diameter of 1.2 to 2.2 cm were randomly and equally divided into 3 groups.Group A received only HIFU irradiation（180 W） without firstly low-dose irradiation.Group B and group C both received firstly low-dose irradiation（80 and 100 W respectively） and then received HIFU ablation（180 W） in 24 h later.The tumor mass was observed with light and electron microscopy before and after ablation.TCC staining was used to evaluate the volume of coagulation necrosis and to calculate the energy efficiency factor（EEF）.Results Group B spent lesser time than group A for the same volume of coagulation necrosis（P0.05）,but group B and C had no significant difference in the time for coagulation necrosis though group C had a larger volume of coagulation necrosis（P0.05）.Compared the 3 groups,the EEF of group A（46.43±13.67） was maximal（P0.05）,and that of group C（7.01±1.33） was minimal（P0.05）.Conclusion The greater power of the first irradiation is,the more obvious efficiency will be achieved.However,it is not wise to blindly increase the power of the first irradiation in oreder to guarantee the safety in clinical HIFU therapy.