Meeson S, Reeves J W, Birch M J, Swain C P, Ikeda K, Feakins R M
Department of Clinical Physics, The Royal London Hospital, London E1 1BB, UK.
Phys Med Biol. 2005 Oct 7;50(19):4553-66. doi: 10.1088/0031-9155/50/19/009. Epub 2005 Sep 21.
Barrett's oesophagus is considered to increase the risk of cancer 30-fold. Helical microwave antennas have been developed for ablative treatment of Barrett's. A microwave balloon applicator was tested in an initial animal study using adult white pigs. For treatment, a balloon filled with tissue-equivalent material encapsulated the antenna. A range of different treatment temperatures and durations was used to investigate a range of thermal ablations of the oesophageal epithelium. Eight animals were investigated, five non-survival and three with a 1-week survival period. The balloon was fitted with an array of temperature sensors, which gave an indication of the treatment in situ and allowed modifications to be performed in real time. Temperature data were recorded from all four quadrants of the balloon throughout and test sites were collected and analysed histologically. All experiments were successfully completed without perforation, serious adverse effects or death. Sites of discrete ulceration were induced in the survival tests, whereas the non-survival tests yielded little reproducible tissue modification. Results suggested that an activation temperature of approximately 55 degrees C needed to be reached during the treatment for tissue damage to be induced. Once damage had been triggered the severity was related to the mean temperature attained during the treatment period. A mean temperature of 52 degrees C or more resulted in substantial damage, whilst a mean temperature of approximately 50 degrees C resulted in the desired surface damage with sparing of subjacent tissues.
巴雷特食管被认为会使患癌风险增加30倍。人们已开发出螺旋微波天线用于巴雷特食管的消融治疗。一种微波球囊施药器在一项使用成年白色猪的初步动物研究中进行了测试。治疗时，一个充满组织等效材料的球囊包裹着天线。使用一系列不同的治疗温度和持续时间来研究食管上皮的一系列热消融情况。对八只动物进行了研究，五只未存活，三只存活一周。球囊装有一系列温度传感器，可指示原位治疗情况并允许实时进行调整。在整个过程中从球囊的所有四个象限记录温度数据，并收集测试部位进行组织学分析。所有实验均成功完成，未出现穿孔、严重不良反应或死亡情况。在存活测试中诱发了离散溃疡部位，而未存活测试产生的可重复组织改变很少。结果表明，治疗期间需要达到约55摄氏度的激活温度才能诱导组织损伤。一旦引发损伤，其严重程度与治疗期间达到的平均温度有关。平均温度达到52摄氏度或更高会导致实质性损伤，而平均温度约为50摄氏度会导致所需的表面损伤，同时使下层组织免受损伤。
