IEEE Trans Ultrason Ferroelectr Freq Control. 2016 Sep;63(9):1234-42. doi: 10.1109/TUFFC.2016.2517644. Epub 2016 Jan 14.
The success of any minimally invasive treatment procedure can be enhanced significantly if combined with a robust noninvasive imaging modality that can monitor therapy in real time. Quantitative ultrasound (QUS) imaging has been widely investigated for monitoring various treatment responses such as chemotherapy, radiation, and thermal therapy. Previously, we demonstrated the feasibility of using spectral-based QUS parameters to monitor high-intensity focused ultrasound (HIFU) treatment of in situ tumors in euthanized rats [Ultrasonic Imaging 36(4), 239-255, 2014]. In the present study, we examined the use of spectral-based QUS parameters to monitor HIFU treatment of in vivo rat mammary adenocarcinoma tumors (MAT) where significant tissue motion was present. HIFU was applied to tumors in rats using a single-element transducer. During the off part of the HIFU duty cycle, ultrasound backscatter was recorded from the tumors using a linear array co-aligned with the HIFU focus. A total of 10 rats were treated with HIFU in this study with an additional sham-treated rat. Spectral parameters from the backscatter coefficient, i.e., effective scatterer diameter (ESD) and effective acoustic concentration (EAC), were estimated. The changes of each parameter during treatment were compared with a temperature profile recorded by a fine-needle thermocouple inserted into the tumor a few millimeters behind the focus of the HIFU transducer. The mean ESD changed from 121 ±6 to [Formula: see text], and the EAC changed from 33 ±2 to [Formula: see text] during HIFU exposure as the temperature increased on average from 38.7 ±1.0 (°)C to 64.2 ±2.7 (°)C. The changes in ESD and EAC were linearly correlated with the changes in tissue temperature during the treatment. When HIFU was turned off, the ESD increased from 81 ±8 to [Formula: see text] and the EAC dropped from 46 ±3 to 36±2 dB/cm(3) as the temperature decreased from 64.2 ±2.7 (°)C to 45 ±2.7 (°)C. QUS was demonstrated in vivo to track temperature elevations caused by HIFU exposure.
如果将实时监测治疗过程的强大无创成像方式与任何微创治疗程序相结合，那么该治疗程序的成功率将会显著提高。定量超声（QUS）成像已被广泛用于监测各种治疗反应，如化疗、放疗和热疗。此前，我们已经证明了使用基于频谱的 QUS 参数来监测高强度聚焦超声（HIFU）治疗处死大鼠原位肿瘤的可行性[Ultrasonic Imaging 36(4), 239-255, 2014]。在本研究中，我们检验了使用基于频谱的 QUS 参数来监测体内大鼠乳腺腺癌肿瘤（MAT）中 HIFU 治疗的可行性，因为该肿瘤存在明显的组织运动。使用单个元件换能器将 HIFU 应用于大鼠肿瘤。在 HIFU 工作周期的关闭部分，使用与 HIFU 焦点对准的线性阵列从肿瘤中记录背向散射。在这项研究中，共有 10 只大鼠接受了 HIFU 治疗，还有 1 只假手术大鼠。从背向散射系数（即有效散射体直径（ESD）和有效声浓度（EAC））中估算了频谱参数。将每个参数在治疗过程中的变化与通过插入到 HIFU 换能器焦点后面几毫米的细针热电偶记录的温度曲线进行了比较。随着温度平均从 38.7 ±1.0 (°) C 升高到 64.2 ±2.7 (°) C，ESD 从 121 ±6 变为 [公式：见文本]，EAC 从 33 ±2 变为 [公式：见文本]。ESD 和 EAC 的变化与治疗过程中组织温度的变化呈线性相关。当 HIFU 关闭时，ESD 从 81 ±8 增加到 [公式：见文本]，EAC 从 46 ±3 下降到 36±2 dB/cm(3)，因为温度从 64.2 ±2.7 (°) C 下降到 45 ±2.7 (°) C。本研究证明了 QUS 可在体内跟踪 HIFU 照射引起的温升。
