title: Cooled microwave transrectal applicator with adjustable directional beam for prostate treatment.
abstract: A new intracavitary applicator design for microwave hyperthermia, particularly for transrectal prostate treatment, is presented. It includes an exchangeable multisection antenna that enables us to create a required longitudinal heating pattern, a cooling system to shift the maximum temperature away from the surface and a microwave reflecting system embedded in the cooling system that allows one to shape the irradiation beam in a transverse direction. Independent control of the longitudinal and transverse irradiation patterns of the applicator along with the cooling system, enable precise heating of selected tissues. Results of SAR measurements, E-field measurements and steady state temperature distributions, in solid and liquid tissue-equivalent phantoms are presented. Clinical performance of this applicator was evaluated earlier in patients heated intraoperatively and in a phase I clinical study. The applicator was found capable of effectively heating a tissue volume extending radially 3-25 mm from the applicator surface, angularly defined by configuration of reflecting system and longitudinally determined by specific choice of the multisection antenna.
authors.affiliation: Department of Radiation Oncology, University of Southern California, School of Medicine, Kenneth Norris Cancer Hospital, Los Angeles 90033.
authors.forename: P S
authors.initials: PS
authors.lastname: Debicki
authors.forename: M
authors.initials: M
authors.lastname: Okoniewski
authors.forename: E
authors.initials: E
authors.lastname: Okoniewska
authors.forename: P N
authors.initials: PN
authors.lastname: Shrivastava
authors.forename: A M
authors.initials: AM
authors.lastname: Debicka
authors.forename: L V
authors.initials: LV
authors.lastname: Baert
authors.forename: Z
authors.initials: Z
authors.lastname: Petrovich
mesh_terms: D000818:Animals; D001831:Body Temperature; D006801:Humans; D006979:Hyperthermia, Induced / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008872:Microwaves; D011469:Prostatic Diseases / Q000628:therapy*; D013997:Time Factors