Development of interstitial antennas for hyperthermic treatment of cancer

我们开发了一种微波同轴环槽应用于肿瘤间质热疗。应用器采用外径0.86 mm的同轴电缆制成的同轴槽天线，使用频率为400 ~ 430mhz微波。几个环形槽，将微波辐射到周围的组织中，沿着电缆的外导体以等距离间隔放置，同轴电缆的尖端被短路以扩大涂敷器尖端周围的加热区域。天线可以插入21g的塑料导管中，通过调整槽的参数可以改变沿其方向的SAR分布。在电缆的外导体上以短间隔布置多个同轴槽。每个天线被装入一个薄塑料导管，然后一组天线被插入肿瘤。在肌肉等量琼脂模型中研究了该涂敷器的加热分布特性。这种涂敷器的优点是相对较大的加热面积和沿涂敷器轴线相对均匀的加热面积。这些优点已经在使用肌肉和植入肿瘤的动物实验中得到证实。组织病理学检查显示大量凝固坏死的肿瘤，有效地加热该应用程序。该涂敷器设计为与430 MHz微波热疗系统配套使用，使其配备的测温和控温系统也可用于间质热疗。

We have developed a microwave coaxial ring-slot applicator for interstitial hyperthermia in cancer therapy. The applicator is co-axial slots antennas made of a 0.86 mm outer diameter coaxial cable, and is used at a frequency of 400-430 MHz microwave. Several ring slots, which radiate microwave power into the surrounding tissue, are placed at equidistant intervals along this cable on the outer conductors, and the tip of the coaxial cable is short-circuited to expand the heating area around the tip of the applicator. The antennas can be inserted into a 21 G plastic catheter and the SAR distribution along them can be changed by ajusting the parameters of the slots. Multiple coaxial slots are arranged at short intervals on the outer conductor of the cable. Each antenna is loaded into a thin plastic catheter and an array of the antennas is then inserted into a tumor.The heating distributions characteristics of this applicator were investigated in the muscle-equivalent agar phantoms. The advantages of this applicator demonstrated were the relatively large haeting area and the relatively uniform heating area along the axis of the applicator. These advantages have been shown in animal experiments using the muscle and the implanted tumor. Histopathological examinations revealed massive coagulation necrosis of the tumors which were effectively heated with this applicater.The applicator was designed to be used with a 430 MHz microwave hyperthermia system, so that the temperature measurement and temperature control system equipped with the system are also availabel for the interstitial hyperthermia.