van der Koijk J F, Crezee J, van Leeuwen G M, Battermann J J, Lagendijk J J
Department of Radiotherapy, University Hospital Utrecht, The Netherlands.
Phys Med Biol. 1996 Mar;41(3):429-44. doi: 10.1088/0031-9155/41/3/007.
The quality of temperature distributions that can be generated with the multi-electrode current source (MECS) interstitial hyperthermia system, which allows 3D control of the spatial SAR distribution, has been investigated. For the investigations, computer models of idealized anatomies were used. These anatomical models did not contain discrete vessels. Binary-media anatomies, containing media interfaces oriented parallel, perpendicular or oblique with respect to the long axis of the implant, represent simple anatomies which can be encountered in the clinic. The implant volume was about 40 cm3. A seven-catheter hexagonal implant geometry with a nearest-neighbor distance of 15 mm was used. In each interstitial probe between one and four electrodes with a diameter of 2.1 mm were placed along an "active section' with a length of 50 mm. The electrode segments had lengths of 50, 20, 12 and 9 mm. This study shows that even with high contrasts in electrical and thermal conductivity in the implant it remains possible to obtain satisfactory temperature distributions with the MECS system. Due to its 3D spatial control the temperature homogeneity in the implant can be made quite satisfactory, with T10-T90 of the order of 2-3 K. Treatment planning must ensure that the placement of the current source electrodes is compatible with the media configuration.
对多电极电流源（MECS）组织间热疗系统所产生的温度分布质量进行了研究，该系统可对空间比吸收率（SAR）分布进行三维控制。在研究中，使用了理想化解剖结构的计算机模型。这些解剖模型不包含离散血管。二元介质解剖结构包含相对于植入物长轴平行、垂直或倾斜的介质界面，代表了临床上可能遇到的简单解剖结构。植入物体积约为40立方厘米。采用了七导管六边形植入几何结构，相邻距离为15毫米。在每个组织间探头中，沿长度为50毫米的“有效段”放置一至四个直径为2.1毫米的电极。电极段长度分别为50、20、12和9毫米。这项研究表明，即使植入物中的电导率和热导率存在高对比度，使用MECS系统仍有可能获得令人满意的温度分布。由于其三维空间控制，植入物中的温度均匀性可以相当令人满意，T10 - T90约为2 - 3K。治疗计划必须确保电流源电极的放置与介质配置兼容。
