Tharp H S, Roemer R B
Department of Electrical and Computer Engineering, University of Arizona, Tucson 85721.
IEEE Trans Biomed Eng. 1992 Jun;39(6):569-79. doi: 10.1109/10.141195.
Improved hyperthermia applicator technology is allowing finer spatial power resolution within the heated tissue volume. Effective utilization of these planar applicator arrays requires an understanding of the interrelationships between the lateral dimensions of the tumor and the applicators, the power field produced by the applicators, the amount of surface cooling, the tumor tissue blood perfusion, and the normal tissue blood perfusion. These interrelationships are investigated using three-dimensional power patterns and temperature fields produced by optimizing the power amplitudes of the individual applicators located within an array of small, but finite, planar applicators. Five major conclusions are obtained. First, optimization works and is effective in determining optimal power fields. Second, for optimal treatments the lateral dimensions of a single superficial applicator need to extend beyond the tumor boundary. Third, surface cooling is needed to reduce the high normal tissue temperatures at shallow depths. Fourth, finer power resolution becomes more important as the tumor size decreases, but, little improvement in the temperature field is achieved beyond a 3 x 3 array configuration. Fifth, increasing the normal blood perfusion rate can decrease the temperature on the tumor boundary if direct power deposition on that boundary is unavailable.
改进的热疗施加器技术能够在受热组织体积内实现更精细的空间功率分辨率。有效利用这些平面施加器阵列需要了解肿瘤和施加器的横向尺寸、施加器产生的功率场、表面冷却量、肿瘤组织血液灌注以及正常组织血液灌注之间的相互关系。利用通过优化位于小型但有限的平面施加器阵列内的各个施加器的功率幅度而产生的三维功率模式和温度场来研究这些相互关系。得出了五个主要结论。第一，优化是可行的，并且在确定最佳功率场方面是有效的。第二，对于最佳治疗，单个浅表施加器的横向尺寸需要延伸到肿瘤边界之外。第三，需要进行表面冷却以降低浅深度处正常组织的高温。第四，随着肿瘤尺寸减小，更精细的功率分辨率变得更加重要，但是，超过3×3阵列配置后，温度场几乎没有改善。第五，如果无法在肿瘤边界上直接进行功率沉积，增加正常血液灌注率可以降低肿瘤边界处的温度。
