微波凝固治疗兔VX_2肿瘤的实验研究

Experimental study on microwave tissue coagulation in hepatic VX_2 carcinoma

目的 探讨术中微波凝固治疗种植性兔肝脏 VX2 肿瘤的有效性 ,并应用能量多普勒声学造影对微波治疗后进行疗效评价。方法 应用 U MC— 1型微波治疗仪 ,2 45 0 MHz,16 G防粘植入性天线 ,芯线裸露长度为 9m m,开腹对 VX2 肿瘤行微波辐射治疗 ,每次 6 0 W× 12 0 s。微波治疗后 10～ 15 m in行能量多普勒声学造影(levovist,30 0 g/ L,0 .2～ 0 .3m L/ kg)。随机抽取微波后各个阶段的 VX2 肿瘤做病理光镜检查。结果 微波治疗后可形成 1.5～ 2 cm的黄白色凝固区 ,肝脏凝固即刻二维超声示沿微波天线呈强回声窄带样改变 ,周围较宽而均匀的低回声反射 ,肿瘤边缘变得不清晰。 2周后肿块内部强回声范围明显扩大 ,周边围以细条状低回声反射 ,肿块边缘清晰可辨 ,其大小与大体所见基本一致。微波治疗后造影检查 ,6个 VX2 肿瘤仅于静脉相观察到稀疏的点状血流 ,2周后病理证实为完全坏死。 4例首次治疗后肿瘤内可见持续血流增强 ,对该区 2次微波治疗后 ,3例结节内未见血流 ,1例 2次治疗后静脉相边缘有持续血流显示 ,2周后再次行造影检查 ,可见中心及周边血流明显增多 ,病理证实为不完全坏死。结论 微波凝固即刻超声增强区与大体标本变性坏死区相差较大 ,2周后超声示肿块边缘清晰 ,超声增强区明显扩大 ,与实际坏死区?

Objective To investigate the effectiveness of microwave tissue coagulation (MTC) in hepatic VX 2 carcinoma and evaluate the contrast enhanced power Doppler ultrasonography detecting the tumor after MTC.Methods The ultrasound microwave therapy 1 (UMT 1) equipment of 9 mm length was inserted directly into the tumor at laparotomy in 10 VX 2 bearing rabbits.The energy output was 60 W×120 s per bout.Postcoagulation contrast enhanced (levovist,300 g/L,0 2～0 3 mL/kg) imaging was performed 10～15 min after treatment.Pathologic anatomy was used as contrast.Results There was 1 5～2 0 cm 2 area of white yellow coagulation after MTC.Along the needle being narrow hyperechoic imaging the broad even hypoechoic imaging was observed around the center immediately after MTC and the edge of tumor was unclear.The intratumoral hyperechoic area extended apparently with a thin striped hypoechoic reflex around in 2 weeks.The edge of tumor was seen distinctly and the hyperechoic area was in accord with the actual volume of necrosis in 2 weeks.Punctiform intratumoral enhanced signal was observed in 6 VX 2 tumors.Pathological findings proved these tumors completely necrotized in 2 weeks.After the first therapy persistent intratumoral color enhancement was still detected in 4 VX 2 tumor.These 4 tumors were retreated with microwave by targeting the areas of colorenhancment.Complete necrosis was seen after the second therapy in 3 of 4 lesions.But persistent enhanced signal of venous phase was seen on the margin of 1 VX 2 tumor and there was a distinctly increased color enhancement in the tumor in 2 weeks;pathological test showed it was of incomplete necrosis.Conclusion Hyperechoic area wasn′t consistent with the actual necrosis volume immediately after the therapy,while being consistent with the volume of actual necrosis 2 weeks later.Contrast enhanced power Doppler US shows promise in assessing the therapeutic effect of microwave on VX 2 tumor.Residual unablated tumor can be seen as a persistent color enhancement.