Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
Okunade, A.A., Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
This paper concerns a method for accurate evaluation of average glandular dose (AGD) in mammography. At different energies, the interactions of photons with tissue are not uniform. Thus, optimal accuracy in the estimation of AGD is achievable when the evaluation is carried out using the normalized glandular dose values, g(x,E), that are determined for each (monoenergetic) x-ray photon energy, E, compressed breast thickness (CBT), x, breast glandular composition, and data on photon energy distribution of the exact x-ray beam used in breast imaging. A generalized model for the values of g(x,E) that is for any arbitrary CBT ranging from 2 to 9 cm (with values that are not whole numbers inclusive, say, 4.2 cm) was developed. Along with other dosimetry formulations, this was integrated into a computer software program, GDOSE.FOR, that was developed for the evaluation of AGD received from any x-ray tube/equipment (irrespective of target-filter combination) of up to 50 kVp. Results are presented which show that the implementation of GDOSE.FOR yields values of normalized glandular dose that are in good agreement with values obtained from methodologies reported earlier in the literature. With the availability of a portable device for real-time acquisition of spectra, the model and computer software reported in this work provide for the routine evaluation of AGD received by a specific woman of known age and CBT. © 2006 American Association of Physicists in Medicine.
article; beam therapy; computer program; device; diagnostic accuracy; dosimetry; energy; evaluation; filter; human; imaging; mammography; methodology; Monte Carlo method; priority journal; radiation dose; spectroscopy; statistical analysis; X ray tube; Algorithms; Body Burden; Breast; Female; Humans; Mammography; Organ Specificity; Radiation Dosage; Radiation Protection; Radiometry; Relative Biological Effectiveness; Risk Assessment; Software