Electron density of tissues and breast cancer radiotherapy: a quantitative CT study.
OBJECTIVE
To obtain more accurate data on the electron density of tissues to be used in the treatment planning of breast cancer patients.


METHODS
Single kVp quantitative computed tomography was applied in 70 women, 20 to 77 years old, to study the electron density of the breast, the thoracic wall close and parallel to the breast, and the lung parenchyma.


RESULTS
The electron density of the entire breast decreases with increasing age in premenopausal women and remains practically constant in postmenopausal women (8% less than that of water). No difference was found in the electron densities of the right and left breast. The electron density of the lung parenchyma in proximity to the breast is lower than the density in the entire lung parenchyma.


CONCLUSIONS
Whenever no accurate data is available on individual patients, the electron density values to be used in treatment planning for breast and thoracic wall have to take into account both age and menstrual status. The regional differences in electron density of the lung also have to be considered.
Medical Physics Department, Medical School, University of Ioannina, Greece.
J A
JA
Kalef-Ezra
A H
AH
Karantanas
T
T
Koligliatis
A
A
Boziari
P
P
Tsekeris
D000328:Adult; D000368:Aged; D001823:Body Composition; D001834:Body Water / Q000737:chemistry; D001940:Breast / Q000737:chemistry*; D001943:Breast Neoplasms / Q000737:chemistry* / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D004583:Electrons; D005260:Female; D006801:Humans; D008168:Lung / Q000737:chemistry; D008875:Middle Aged; D013909:Thorax / Q000737:chemistry; D014057:Tomography, X-Ray Computed