微泡增强的超声空化阻断肿瘤微循环的初步研究

目的研究微泡增强的超声空化阻断肿瘤微循环的可行性。方法 26只皮下VX_2肿瘤荷瘤兔随机分为超声微泡组、单纯超声组及假照组。超声微泡组经耳缘静脉推注微泡联合超声辐照肿瘤,单纯超声组以生理盐水代替微泡,假照组超声假照。各组治疗前、治疗后0、30和60min时间点对肿瘤进行超声造影,分析各时间点造影灌注峰值灰阶变化。结果超声微泡组肿瘤造影灰阶值(级)从治疗前的(67.8±13.3)级降至(29.7±20.1)级(P0.01),维持超过60min仍无明显再通;而单纯超声组、假照组肿瘤造影灰阶值无明显变化(P0.05)。结论微泡增强的超声空化能够有效阻断兔VX_2皮下肿瘤的微循环,其发生机制尚不清楚。

Tumor Microcirculation Obstructed by Microbubbles Enhanced Ultrasound Cavitation

Objective To investigate the possible obstruction effects of microbubbles (MBs) enhanced ultrasound (US) cavitation on tumor microcirculation.Methods 26 rabbits bearing subcutaneous VX2 tumor were randomly divided into three groups.Pulse US was delivered to the tumor for 10 minutes during intravenous infusion of microbubbles at 0.2 ml/kg in the experimental group(US +MBs).The control groups were applied with only US exposure or MBs injection.The tumor perfusion was imaged using contrast enhanced ultrasonography before and 0 min,30 mins,and 60 mins after treatment.Results The contrast perfusion of VX2 tumors almost vanished immediately after treatment in the US+MBs group,with the gray scale value (GSV) reduced from 67.8±13.3 (before) to 29.7±20.1 (post,P<0.01).There was no GSV significance before and after treatment (P>0.05) in the two control groups.Conclusions The VX2 tumor micro-circulation can be blocked by microbubbles enhanced ultrasound cavitation,the mechanism remained unknown.