Linked Life Data

7141916

Source:http://linkedlifedata.com/resource/pubmed/id/7141916

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1983-1-7
pubmed:abstractText
Accurate dose calculations for radiotherapy planning require a detailed knowledge of the internal anatomy of the patient both in terms of geometry and density. Computed tomography (CT) is presently the best means of providing these data. Fifty-eight patients who had scans of the thorax for radiotherapy planning were studied. The CT numbers were converted to relative electron densities and average lung densities were obtained for every patient. A linear correlation of lung density with age was found with the mean lung density of 0.35 at an age 5 years and 0.19 at an age of 80. The effect of scanning the patient under full inspiration, full expiration or normal shallow breathing conditions was analyzed. At the age of 5 years the expiration and inspiration average lung densities were 0.36 and 0.20, while at the age of 80 years they were 0.22 and 0.16, respectively. Respiratory volume changes were linearly correlated with changes in relative electron density. Differences in lung density between expiration and inspiration scans were found to demonstrate a similar trend with age as the relationship between vital capacity and age. The dosimetric and the possible clinical implications of lung density measurements for radiotherapy are considered. In particular, dose calculations were performed using scans taken under a number of different respiratory conditions. Doses calculated for a single cobalt-60 beam can differ by more than 25% when comparing a full inspiration scan to a normal breathing scan. A similar comparison for a parallel pair distribution on the lung yields a difference of about 3% while a typical three field technique for treating cancer of the esophagus shows a difference of nearly 10%.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0360-3016
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1363-72
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
Lung density as measured by computerized tomography: implications for radiotherapy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't