Evaluation of multielement catheter-cooled interstitial ultrasound applicators for high-temperature thermal therapy
Evaluation of multielement catheter-cooled interstitial ultrasound applicators for high-temperature thermal therapy
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DOI：
10.1118/1.1381550
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发表时间：
2001-07-01
期刊：
影响因子：
3.8
通讯作者：
Burdette, EC
中科院分区：
文献类型：
--
作者：
Nau, WH;Diederich, CJ;Burdette, EC
对导管冷却(CC)组织间超声辐射器在组织高温凝固热疗中的应用进行了评价。在体外牛肉实验中，研究了外加电功率(5~20W)、导管流量(20~60mlmin(-1))、循环水温度(7~40℃)和频率(7~9 MHz)对温度分布和热损伤几何形状的影响。还研究了使用多个间质涂抹器对预定体积的组织进行热凝的可行性。这些研究的结果表明，随着时间和功率的增加，热损伤的方向性形状保持不变。5W加热4min后，热灶的径向深度为10.7+/-0.7 mm，20W时为16.2+/-1.4 mm。热灶的轴向长度受有效探头数目的控制。确定导管流速为20-40mlmin(-1)(在40mlmin(-1)时为52.2+/-5.5kpa)，用22度C水为换能器提供足够的冷却以满足本研究所使用的功率水平。在活体中，四个涂抹器直径3厘米的猪大腿肌肉周围植入物的中心温度在加热4分钟后达到89.3摄氏度，凝血边界由涂抹器位置和方向性明确界定。在一个临床相关的模型中，通过在活体犬前列腺内插入两个间隔2厘米的定向CC喷涂器，并在引导能量远离直肠并保护直肠的同时，产生横截面为3.8 cm×2.2 cm的热损伤，证明了加热的一致性。在加热20分钟内，中间腺体的最高测量温度超过90摄氏度。这项研究的结果证明了单个或多个CC敷贴器用于适形热凝和高温热疗的有效性，在前列腺、肝脏、乳房或子宫等部位具有临床应用的潜力。(C)2001年美国医学物理学家协会。
Catheter-cooled (CC) interstitial ultrasound applicators were evaluated for their use in high-temperature coagulative thermal therapy of tissue. Studies in ex vivo beef muscle were conducted to determine the influences of applied electrical power levels (5-20 W per element), catheter flow rate (20-60 ml min(-1)), circulating water temperature (7-40 degreesC), and frequency (7-9 MHz) on temperature distribution and thermal lesion geometry. The feasibility of using multiple interstitial applicators to thermally coagulate a predetermined volume of tissue was also investigated. Results of these studies revealed that the directional shape of the thermal lesions is maintained with increasing time and power. Radial depths of the thermal lesions ranged from 10.7+/-0.7 mm after heating for 4 min with an applied power level of 5 W. to 16.2+/-1.4 mm with 20 W. The axial length of the thermal lesions is controlled tightly by the number of active transducers. A catheter flow rate of 20 to 40 ml min(-1) (52.2+/-5.5 kPa at 40 ml min(-1)) with 22 degreesC water was determined to provide sufficient cooling of the transducers for power levels used in this study. In vivo temperatures measured in the center of a 3-cm-diam peripheral implant of four applicators in pig thigh muscle reached 89.3 degreesC after 4 min of heating, with boundaries of coagulation clearly defined by applicator position and directivity. Conformability of heating in a clinically relevant model was demonstrated by inserting two directional CC applicators with a 2 cm separation within an in vivo canine prostate, and generating a thermal lesion measuring 3.8 cmx2.2 cm in cross section while directing energy away from, and protecting the rectum. Maximum measured temperatures at midgland exceeded 90 degreesC within 20 min of heating. The results of this study demonstrate the utility of single or multiple CC applicators for conformal thermal coagulation and high temperature thermal therapy, with potential for clinical applications in sites such as prostate, liver, breast, or uterus. (C) 2001 American Association of Physicists in Medicine.