title: Heating patterns of the Helios ultrasound hyperthermia system.
abstract: Thermal dosimetry studies of the Helios ultrasound system were performed in a tissue-equivalent phantom and in porcine tissues in vivo. SAR distributions in the phantom demonstrate the adjustability of the power deposition pattern from the 50 cm diameter annular array of 30 transducers. Examples are given of well-localized SAR patterns (< 3 cm diameter) in the phantom, and of peripherally enhanced (doughnut-shaped) SAR patterns up to 10 cm in diameter at the focal plane. In vivo trials in porcine thigh muscle demonstrate the ability of the Helios system to produce regions of therapeutic heating (42-45 degrees C) as small as 20 cm3 and as large as 200 cm3 at depths of greater than 10 cm at a frequency of 0.5 MHz.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021.
authors.forename: K
authors.initials: K
authors.lastname: Lindsley
authors.forename: P R
authors.initials: PR
authors.lastname: Stauffer
authors.forename: P
authors.initials: P
authors.lastname: Sneed
authors.forename: R
authors.initials: R
authors.lastname: Chin
authors.forename: T L
authors.initials: TL
authors.lastname: Phillips
authors.forename: E
authors.initials: E
authors.lastname: Seppi
authors.forename: E
authors.initials: E
authors.lastname: Shapiro
authors.forename: S
authors.initials: S
authors.lastname: Henderson
mesh_terms: D000818:Animals; D001831:Body Temperature; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008961:Models, Structural; D009369:Neoplasms / Q000628:therapy*; D013552:Swine; D013821:Thermometers; D014464:Ultrasonic Therapy / Q000295:instrumentation* / Q000379:methods