An improved design of a previously described intracavitary microwave hyperthermia applicator is presented. The applicator consists of a coaxial choke antenna designed to be positioned into a perspex obturator. The antenna can be fitted in the obturator in three defined positions depending on the specific clinical situation: the selected median, paramedian or lateral position can each provide differently directed heating patterns. This feature combined with the additional axial variability of the antenna position within the obturator can lead to a highly targeted heating of tumours and a reduced risk of unwanted heating of normal tissues. Various phantom studies were conducted using both liquid and solid phantoms. The saline phantom was used to check the typical action of the choke of the antenna where it was found that the antenna choke is efficiently working resulting in a heating pattern which is dependent of the insertion depth of the antenna. The solid phantom was used to measure the typical specific absorption rate (SAR) distribution of each antenna/obturator configuration.
A microwave applicator for interstitial hyperthermia was designed for use in conjunction with interstitial radiation therapy. Measurements were performed in phantom material and in the hind legs of anaesthetized pigs. In both studies two applicators were inserted in parallel at a distance of 2 cm and to a depth of 6 cm. The temperature distribution produced by two conventional applicators were compared with the temperature distribution produced by two applicators of the new design. Improvement of the heating pattern was found in both phantom and animal studies; the heating pattern produced by the new applicators was shifted towards the tip. This may be of clinical importance as heating can be achieved without applicator penetration through tumour tissue into normal tissue.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.