Oshima Fumiyoshi, Yamakado Koichiro, Nakatsuka Atsuhiro, Takaki Haruyuki, Makita Masashi, Takeda Kan
Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu, 514-8507, Japan.
Radiat Med. 2008 Aug;26(7):408-14. doi: 10.1007/s11604-008-0251-x. Epub 2008 Sep 4.
Our purpose was to determine the optimal antenna spacing to achieve large ablative zones without indentations when microwave ablation is performed with simultaneous activation of two or three antennas.
Microwave ablation was performed with single-antenna activation and simultaneous activation of two or three antennas with a spacing of 1.5, 2.0, 2.5, or 3.0 cm in explanted bovine livers. Microwave energy was applied for 10 min with a power of 45 W. The shapes and sizes of the ablative zones created were recorded and compared.
The shape of the ablative zone was ellipsoid in the axial plane (along the antenna axis) and spherical in the transverse plane (perpendicular to the antenna axis) in single-antenna ablation. The ablative zones were spherical or ellipsoid in both the axial and transverse planes in two-and three-antenna ablation with an antenna spacing of 2.0 cm or less. Indentations were observed between the ablative zones created by the antennas when the spacing was 2.5 cm or more, reducing the minimum transverse diameter. When two-or three-antenna ablation was performed with a spacing of 2.0 cm or less, the axial and minimum transverse diameters were significantly larger than in single-antenna ablation. The largest volume (almost two or three times the single-activation volume) was achieved in two-or three-antenna ablation with an antenna spacing of 2.0 cm.
We found that simultaneous microwave ablation using multiple microwave antennas creates large ablative zones without indentations when multiple antennas are activated with an antenna spacing of 2.0 cm or less.
我们的目的是确定在同时激活两根或三根天线进行微波消融时，实现无凹陷的大消融区的最佳天线间距。
在离体牛肝中进行单天线激活以及天线间距为1.5、2.0、2.5或3.0 cm的两根或三根天线同时激活的微波消融。以45 W的功率施加微波能量10分钟。记录并比较所产生的消融区的形状和大小。
在单天线消融中，消融区在轴向平面（沿天线轴）呈椭圆形，在横向平面（垂直于天线轴）呈球形。在天线间距为2.0 cm或更小的双天线和三天线消融中，消融区在轴向和横向平面均为球形或椭圆形。当天线间距为2.5 cm或更大时，在天线产生的消融区之间观察到凹陷，减小了最小横向直径。当以2.0 cm或更小的间距进行双天线或三天线消融时，轴向和最小横向直径显著大于单天线消融。在天线间距为2.0 cm的双天线或三天线消融中实现了最大体积（几乎是单激活体积的两到三倍）。
我们发现，当以2.0 cm或更小的天线间距激活多根微波天线时，同时进行微波消融可产生无凹陷的大消融区。
