High intensity focused ultrasound induced in vivo large volume hyperthermia under 3D MRI temperature control
High intensity focused ultrasound induced in vivo large volume hyperthermia under 3D MRI temperature control
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DOI：
10.1118/1.4942378
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发表时间：
2016-03-01
期刊：
影响因子：
3.8
通讯作者：
Kohler, Max
中科院分区：
文献类型：
--
作者：
Tillander, Matti;Hokland, Steffen;Kohler, Max
目的：亚温热疗法可作为一种辅助治疗手段，加强肿瘤的放疗或化疗。然而，由于温度控制所需的高精度，管理轻度热疗在技术上具有挑战性。MR引导高强度聚焦超声（MR-HIFU）是一种可以解决这一挑战的技术。在这项工作中，准确的和空间均匀的轻度热疗证明了深层次的临床相关的加热量使用高强度聚焦超声系统在MR guidance.Methods：轻度热疗加热的温度精度和空间均匀性进行了评估，在11个在体内猪腿实验。使用嵌入1.5T Ingenia MR扫描仪的商业Philips Sonalleve MR-HIFU系统诱导热疗。对操作软件进行了修改，以允许延长持续时间的轻度高温。加热时间从10分钟到60分钟不等，指定的目标温度为42.5 ℃。利用电子焦点控制、机械换能器移动和动态换能器元件关闭来扩大加热体积并在整个声束路径上获得均匀加热。磁场漂移和传感器磁化率伪影进行补偿，使准确的体积MR thermometry.Results：所获得的平均温度为目标区域（在焦深加热体积的横截面积主要用于控制加热）平均为42.0 +/- 0.6摄氏度。使用T10和T90评估目标区域的温度均匀性，其分别为43.1 +/- 0.6和40.9 +/- 0.6 ℃。对于近场，相应的温度为39.3 +/- 0.8摄氏度（平均），40.6 +/- 1.0摄氏度（T10）和38.0 +/- 0.9摄氏度（T90）。超声处理产生简洁的加热体积，通常为截头圆锥形。从皮肤到达的平均深度为86.9 mm。结果表明，加热算法能够诱导深层加热，同时保持近场温度均匀，并在一个安全的level.Conclusions：MR-HIFU的能力，诱导准确，空间均匀，强大的轻度热疗在大的深埋体积成功地证明了通过一系列的体内动物实验。(C)2016年美国医学物理学家协会。
Purpose: Mild hyperthermia can be used as an adjuvant therapy to enhance radiation therapy or chemotherapy of cancer. However, administering mild hyperthermia is technically challenging due to the high accuracy required of the temperature control. MR guided high-intensity focused ultrasound (MR-HIFU) is a technology that can address this challenge. In this work, accurate and spatially uniform mild hyperthermia is demonstrated for deep-seated clinically relevant heating volumes using a HIFU system under MR guidance.Methods: Mild hyperthermia heating was evaluated for temperature accuracy and spatial uniformity in 11 in vivo porcine leg experiments. Hyperthermia was induced with a commercial Philips Sonalleve MR-HIFU system embedded in a 1.5T Ingenia MR scanner. The operating software was modified to allow extended duration mild hyperthermia. Heating time varied from 10 min up to 60 min and the assigned target temperature was 42.5 degrees C. Electronic focal point steering, mechanical transducer movement, and dynamic transducer element switch-off were exploited to enlarge the heated volume and obtain uniform heating throughout the acoustic beam path. Multiple temperature mapping images were used to control and monitor the heating. The magnetic field drift and transducer susceptibility artifacts were compensated to enable accurate volumetric MR thermometry.Results: The obtained mean temperature for the target area (the cross sectional area of the heated volume at focal depth primarily used to control the heating) was on average 42.0 +/- 0.6 degrees C. Temperature uniformity in the target area was evaluated using T10 and T90, which were 43.1 +/- 0.6 and 40.9 +/- 0.6 degrees C, respectively. For the near field, the corresponding temperatures were 39.3 +/- 0.8 degrees C (average), 40.6 +/- 1.0 degrees C (T10), and 38.0 +/- 0.9 degrees C (T90). The sonications resulted in a concise heating volume, typically in the shape of a truncated cone. The average depth reached from the skin was 86.9 mm. The results show that the heating algorithm was able to induce deep heating while keeping the near-field temperature uniform and at a safe level.Conclusions: The capability of MR-HIFU to induce accurate, spatially uniform, and robust mild hyperthermia in large deep-seated volumes was successfully demonstrated through a series of in vivo animal experiments. (C) 2016 American Association of Physicists in Medicine.