by Ernst-Günter Lierke, Tobias Hemsel, Leibenger
Abstract:
Ultrasonic hyperthermia and thermo-ablation are two promising alternatives for local overheating of deep-seated human tumours. After a short characterisation of the two techniques and the identification of the main parameters, results of an analytical theory of local heat up, cooling, and heat diffusion are presented. The theory is based on a spherical model for hyperthermia with a critical thermal dose and on a cylinder-symmetrical model for thermo-ablation with a critical temperature threshold for thermal toxicity and cell death through coagulative necrosis. Two representative hard ware concepts are discussed. The hyperthermia applicator consists of a MHz transducer, which rotates concentrically in a water filled capsule with acoustically transparent window, and radiates collimated or focussed ultrasound under 45$\,^\circ$ into a concentric target area of nearly spherical symmetry. The applicator for thermo-ablation is a MHz transducer which radiates high intensity focussed ultrasound (HIFU) into "cigar shaped" target areas at the focal zone. Typical therapy diagrams for both techniques are presented. They show therapeutic target volumes as functions of the therapy time with the peak temperature or the radiated acoustic power as parameters. These diagrams are discussed under consideration of power requirement, maximal sound intensity, and power efficiency at close to optimized frequency conditions.
Reference:
Lierke, E.; Hemsel, T.; Leibenger, : Local Ultrasonic Hyperthermia and Thermo-ablation: A Description and Theoretical Evaluation of Two Alternative Concepts for the Heat Therapy of Tumours. Acta Acustica united with Acustica, volume 94, 2008.
Bibtex Entry:
@ARTICLE{Lierke2008,
author = {Lierke, Ernst-G{\"u}nter and Hemsel, Tobias and Leibenger},
title = {Local Ultrasonic Hyperthermia and Thermo-ablation: A Description
and Theoretical Evaluation of Two Alternative Concepts for the Heat
Therapy of Tumours},
journal = {Acta Acustica united with Acustica},
year = {2008},
volume = {94},
pages = {369-381},
number = {3},
__markedentry = {[K. Agbons jr:6]},
abstract = {Ultrasonic hyperthermia and thermo-ablation are two promising alternatives
for local overheating of deep-seated human tumours. After a short
characterisation of the two techniques and the identification of
the main parameters, results of an analytical theory of local heat
up, cooling, and heat diffusion are presented. The theory is based
on a spherical model for hyperthermia with a critical thermal dose
and on a cylinder-symmetrical model for thermo-ablation with a critical
temperature threshold for thermal toxicity and cell death through
coagulative necrosis. Two representative hard ware concepts are discussed.
The hyperthermia applicator consists of a MHz transducer, which rotates
concentrically in a water filled capsule with acoustically transparent
window, and radiates collimated or focussed ultrasound under 45$\,^{\circ}$
into a concentric target area of nearly spherical symmetry. The applicator
for thermo-ablation is a MHz transducer which radiates high intensity
focussed ultrasound (HIFU) into "cigar shaped" target areas at the
focal zone. Typical therapy diagrams for both techniques are presented.
They show therapeutic target volumes as functions of the therapy
time with the peak temperature or the radiated acoustic power as
parameters. These diagrams are discussed under consideration of power
requirement, maximal sound intensity, and power efficiency at close
to optimized frequency conditions.},
bdsk-url-1 = {http://www.ingentaconnect.com/content/dav/aaua/2008/00000094/00000003/art00004},
bdsk-url-2 = {http://dx.doi.org/10.3813/AAA.918044},
doi = {doi:10.3813/AAA.918044},
owner = {K. Agbons jr},
timestamp = {2013.11.23},
url = {http://www.ingentaconnect.com/content/dav/aaua/2008/00000094/00000003/art00004}
}