Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2000-12-11
pubmed:abstractText
This study investigates the optimal external parameters for using an ultrasound applicator for treating bone tumors. This system utilized spherically arranged applicators such as scanned focused ultrasound, and spherically focused multielement applicators. The power deposition pattern is modeled as geometric gain with exponential attenuation. The specific absorption rate ratio (SARR) criteria have been used to determine the proper heating domain of ultrasound driving frequency and therapeutic tumor diameter. The results demonstrate that the optimal driving frequency depends on tumor depth, ultrasound absorption of bone marrow, and diameter of bone, but it is independent of the acoustic window area and SARR. The treatable diameter of bone tumor increased when the absorption ratio of bone marrow to tumor, acoustic window of surface skin, and diameter of bone were elevated. However, the treatable diameter of bone tumor decreased when muscle thickness, SARR of bone tumor site to the surface skin, bone marrow, and bone declined. To deliver the ultrasound energy into the tumor site and to avoid the potential damage to the normal tissue as much as possible, the specific absorption rate (SAR) in the bone tumor site has to be three times higher than that in the surface skin, tumor/marrow, and marrow/bone interfaces. The temperature distributions can verify the SARR criteria in this model. This study provides the information for choosing the optimal operating frequency of the ultrasound transducer and the acoustic window on the skin surface, and for designing the ultrasound applicator for clinical implementation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1350-4533
pubmed:author
pubmed:issnType
Print
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
253-63
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Theoretical study of convergent ultrasound hyperthermia for treating bone tumors.
pubmed:affiliation
Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, ROC.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't