Focused ultrasound treatment of VX2 tumors controlled by local harmonic motion
Focused ultrasound treatment of VX2 tumors controlled by local harmonic motion
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DOI：
10.1088/0031-9155/54/11/009
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发表时间：
2009-06-07
影响因子：
3.5
通讯作者：
Hynynen, Kullervo
中科院分区：
文献类型：
--
作者：
Curiel, Laura;Huang, Yuexi;Hynynen, Kullervo
本研究的目的是评估使用局部谐波运动（LHM）监测和控制聚焦超声手术（FUS）在体内VX 2肿瘤中的可行性。对植入9只家兔体内的13个VX 2肿瘤进行FUS暴露。相同的换能器通过周期性地改变辐射力诱导凝固并产生局部振荡运动。一个单独的诊断超声换能器通过在不同情况下互相关回波信号来跟踪运动。设定阈值运动幅度以停止暴露。通过T2加权MR图像、通过MR测温获得的热剂量和组织学检查证实凝血。对于实现凝固的肿瘤位置，LHM振幅比暴露前低9%（p = 0.04）至57%（p < 0.0001）。108例中74例（69%）控制成功，52例（48%）达到阈值并实现凝血，22例（21%）从未达到阈值或凝血。在34例（31%）不成功的暴露中，16例（15%）从未达到阈值但发生凝血，18例（16%）达到阈值但未确认凝血。在24例（22%）病例中，噪音或射频信号变化解释了运动高估或低估;其余10例（9%）有其他错误原因。控制通常是成功的，但是所获取的回波信号中的突然变化或噪声导致失败。暴露后的凝血可通过比较暴露前后的振幅进行验证。
The purpose of this study was to evaluate the feasibility of using localized harmonic motion (LHM) to monitor and control focused ultrasound surgery (FUS) in VX2 tumors in vivo. FUS exposures were performed on 13 VX2 tumors implanted in nine rabbits. The same transducer induced coagulation and generated a localized oscillatory motion by periodically varying the radiation force. A separate diagnostic ultrasound transducer tracked motion by cross-correlating echo signals at different instances. A threshold inmotion amplitude was instituted to cease exposure. Coagulation was confirmed by T2-weighted MR images, thermal dose obtained through MR thermometry and histological examinations. For tumor locations achieving coagulation, the LHM amplitude was 9% (p = 0.04) to 57% (p < 0.0001) lower than that before exposure. Control was successful for 74 (69%) out of 108 cases, with 52 (48%) reaching the threshold and achieving coagulation and 22 (21%) never reaching threshold nor coagulating. For the 34 (31%) unsuccessful exposures, 16 (15%) never reached the threshold but coagulation occurred, and 18 (16%) reached threshold without coagulation confirmed. Noise or radio-frequency signal changes explained motion over- or underestimation in 24 (22%) cases; the remaining 10 (9%) had other causes of error. The control was generally successful, but sudden change or noise in the acquired echo signal caused failure. Coagulation after exposure could be validated by comparing amplitudes before and after exposure.