Microwave antennas for thermal ablation of benign adrenal adenomas
Microwave antennas for thermal ablation of benign adrenal adenomas
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DOI：
10.1088/2057-1976/ab068b
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发表时间：
2019-02-01
影响因子：
1.4
通讯作者：
Prakash, Punit
中科院分区：
文献类型：
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作者：
Fallahi, Hojjatollah;Clausing, Daniel;Prakash, Punit
微波热消融正在考虑作为治疗 10-20 毫米良性肾上腺腺瘤的微创方式，同时保留正常功能的邻近肾上腺组织，并使腺体恢复到正常调节下的正常功能状态。与肿瘤消融应用相比，开发设备的目的是最大化消融区域的大小以治疗大肿瘤，肾上腺消融的挑战是最大限度地减少对非目标肾上腺组织的热损伤，从而保留肾上腺功能。在这里，我们研究使用工作频率为 2.45 GHz 和 5.8 GHz 的载水微波单极天线创建体积在 0.5-4 cm(3) 范围内的小球形消融区域以治疗良性肾上腺腺瘤的方法。采用耦合电磁和生物热传递模拟和离体组织实验来研究频率、施加功率、消融持续时间和冷却剂温度对消融区域的长度和宽度的影响。实验结果表明，通过调节施加功率和消融持续时间，可以获得直径在7.4-17.6 mm范围内的小球形消融区域。对实验测量的消融区尺寸的多向方差分析表明，操作频率和消融持续时间分别是控制消融区长度和宽度的主要参数。此外，事实证明，冷却剂温度提供了另一个有效参数来控制消融区长度而不影响消融区宽度。我们的研究证明了创建适合针对良性肾上腺腺瘤的小型球形微波消融区域的可行性。
Microwave thermal ablation is under consideration as a minimally invasive modality to treat 10-20 mm benign adrenal adenomas, while preserving normally functioning adjacent adrenal tissue, and returning the gland to a normally functioning status that is under normal regulation. In contrast to applications for tumor ablation, where devices have been developed with the objective of maximizing the size of the ablation zone for treating large tumors, a challenge for adrenal ablation is to minimize thermal damage to non-targeted adrenal tissue and thereby preserve adrenal function. Here, we investigate methods for creating small spherical ablation zones of volumes in the range 0.5-4 cm(3) for the treatment of benign adrenal adenomas using water-loaded microwave monopole antennas operating at 2.45 GHz and 5.8 GHz. Coupled electromagnetic and bioheat transfer simulations and experiments in ex vivo tissue were employed to investigate the effect of frequency, applied power, ablation duration, and coolant temperature on the length and width of the ablation zone. Experimental results showed that small spherical ablation zones with diameters in the range of 7.4-17.6 mm can be obtained by adjusting the applied power and ablation duration. Multi-way ANOVA analysis of the experimentally-measured ablation zone dimensions demonstrated that frequency of operation and ablation duration are the primary parameters for controlling the ablation zone length and width, respectively. Additionally, it was demonstrated that the coolant temperature provides another effective parameter for controlling the ablation zone length without affecting the ablation zone width. Our study demonstrates the feasibility of creating small spherical microwave ablation zones suitable for targeting benign adrenal adenomas.