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SonoKnife: Feasibility of a line‐focused ultrasound device for thermal ablation therapy
Author(s) -
Chen Duo,
Xia Rongmin,
Chen Xin,
Shafirstein Gal,
Corry Peter M.,
Griffin Robert J.,
Penagaricano Jose A.,
TulunayUgur Ozlem E.,
Moros Eduardo G.
Publication year - 2011
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3601017
Subject(s) - transducer , materials science , imaging phantom , ultrasound , ablation , acoustics , thermal , optics , enhanced data rates for gsm evolution , ultrasonic sensor , biomedical engineering , physics , computer science , medicine , telecommunications , aerospace engineering , meteorology , engineering
Purpose: To evaluate the feasibility of line‐focused ultrasound for thermal ablation of superficially located tumors. Methods: A SonoKnife is a cylindrical‐section ultrasound transducer designed to radiate from its concave surface. This geometry generates a line‐focus or acoustic edge. The motivation for this approach was the noninvasive thermal ablation of advanced head and neck tumors and positive neck nodes in reasonable treatment times. Line‐focusing may offer advantages over the common point‐focusing of spherically curved radiators such as faster coverage of a target volume by scanning of the acoustic edge. In this paper, The authors report studies using numerical models and phantom and ex vivo experiments using a SonoKnife prototype. Results : Acoustic edges were generated by cylindrical‐section single‐element ultrasound transducers numerically, and by the prototype experimentally. Numerically, simulations were performed to characterize the acoustic edge for basic design parameters: transducer dimensions, line‐focus depth, frequency, and coupling thickness. The dimensions of the acoustic edge as a function of these parameters were determined. In addition, a step‐scanning simulation produced a large thermal lesion in a reasonable treatment time. Experimentally, pressure distributions measured in degassed water agreed well with acoustic simulations, and sonication experiments in gel phantoms and ex vivo porcine liver samples produced lesions similar to those predicted with acoustic and thermal models. Conclusions : Results support the feasibility of noninvasive thermal ablation with a SonoKnife.