Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam, The Netherlands.
Phys Med Biol. 2013 Sep 7;58(17):5997-6009. doi: 10.1088/0031-9155/58/17/5997. Epub 2013 Aug 12.
Accumulating evidence shows that hyperthermia improves head-and-neck cancer treatment. Over the last decade, we introduced a radiofrequency applicator, named HYPERcollar, which enables local heating also of deep locations in this region. Based on clinical experience, we redesigned the HYPERcollar for improved comfort, reproducibility and operator handling. In the current study, we analyze the redesign from an electromagnetic point of view. We show that a higher number of antennas and their repositioning allow for a substantially improved treatment quality. Combined with the much better reproducibility of the water bolus, this will substantially minimize the risk of underexposure. All improvements combined enable a reduction of hot-spot prominence (hot-spot to target SAR quotient) by 32% at an average of 981 W, which drastically reduces the probability for system power to become a treatment limiting source. Moreover, the power deposited in the target selectively can be increased by more than twofold. Hence, we expect that the HYPERcollar redesign currently under construction allows us to double the clinically applied power to the target while reducing the hot-spots, resulting in higher temperatures and, consequently, better clinical outcome.
越来越多的证据表明，热疗可以改善头颈部癌症的治疗效果。在过去的十年中，我们引入了一种名为 HYPERcollar 的射频应用器，它可以实现该区域深部位置的局部加热。基于临床经验，我们对 HYPERcollar 进行了重新设计，以提高舒适度、重现性和操作人员的操控性。在当前的研究中，我们从电磁场的角度分析了重新设计。我们表明，增加天线的数量并重新定位天线可以显著提高治疗质量。结合水囊的更好重现性，这将大大降低欠曝光的风险。所有改进措施相结合，可以将热点突出度（热点与目标 SAR 比值）降低 32%，平均功率为 981 W，这大大降低了系统功率成为治疗限制源的概率。此外，还可以将目标中沉积的功率选择性地增加两倍以上。因此，我们预计正在进行中的 HYPERcollar 重新设计将使我们能够将目标应用的功率提高一倍，同时降低热点，从而提高温度，进而获得更好的临床效果。
