DOI: 10.1615/ICHMT.2008.CHT
ISBN Print: 978-1-56700-253-9
ISSN: 2578-5486
HEAT TRANSFER IN INTERSTITIAL ULTRASOUND HEATING OF BRAIN TUMORS, INCLUDING THE EFFECT OF BIFURCATED BLOOD VESSELS
要約
We discuss the role of a blood vessel bifurcation on heating in the brain using ultrasound interstitial applicators. The applicators, arranged in an array with their axis at the corners of a 2.6 × 10−2 m side quadrangle, were a heat source. A bifurcation of a 1.5-mm artery located near the midline into a 1.1- and 0.6-mm branch is considered. The smaller branch was modeled near one of the applicators with the larger one at the brain boundary. Several FEA models of the brain were evaluated at 0−150 ml/min blood flow range. The simplified model including the vessels was found to be useful in preliminary finding of the temperature patterns. To obtain accurate prediction of thermal dose and heat toxicity, additional structures need be included. Detailed studies of thermal dose and heat toxicity patterns were carried out at 45 and 100 ml/min flow. They showed that, at a fixed heat deposition, to remove reductions in the dose near the small branch required an increase in treatment time from 87 to 114 min at the lower flow and from 95 to 106 min at 100 ml/min. A consequence of this increase in time is raise in heat toxicity volume. Since reduction of the therapeutic volume of less than 10% was localized to vicinity of the vessels, it was concluded that both the dose and 3D temperature pattern should be concurrently used and other descriptive factors must be utilized in realistic treatment planning.