A NEW MICROWAVE APPLICATOR WITH INTEGRATED COOLING SYSTEM FOR INTRACAVITARY HYPERTHERMIA OF VAGINAL-CARCINOMA

An improved design of a previously described intracavitary microwave h yperthermia applicator is presented. The applicator consists of a coax ial 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, par amedian or lateral position can each provide differently directed heat ing patterns. This feature combined with the additional axial variabil ity 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 liqu id and solid phantoms. The saline phantom was used to check the typica l action of the choke of the antenna where it was found that the anten na choke is efficiently working resulting in a heating pattern which i s dependent of the insertion depth of the antenna. The solid phantom w as used to measure the typical specific absorption rate (SAR) distribu tion of each antenna/obturator configuration.