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Sci—Fri AM(1): Imaging—02: Estimation of Patient Dose in a Provincial Screening Mammography Program
Author(s) -
Rajapakshe R
Publication year - 2009
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3244185
Subject(s) - mammography , nuclear medicine , digital mammography , dosimetry , medicine , medical physics , screening mammography , radiation dose , web site , breast cancer , computer science , cancer , the internet , world wide web
PURPOSE: To estimate the radiation dose delivered to women in an organized provincial breast screening program. METHOD AND MATERIALS: Volunteer technologists from 39 screening sites were asked to record the techniques factors of the four bilateral mammograms of 50 consecutive women who underwent screening in April of 2007. Volunteers from 31 sites responded to this request (80%). Data collected were then analyzed statistically for each site as well as collectively. Three methods were used to assess mean glandular dose (MGD): 1) parameterization of tables published by Wu et al (W.T. Sobol and X. Wu, Med. Phys. 1997), 2) conversion factors tables based on data established by Dance (D. Dance, C. Skinner, K. Young, Phys. Med. Biol 2000), and 3) interpolation of lookup tables provided by Boone (J. Boone, Radiology 1999). Radiation output data needed for the calculations were obtained from the annual physics surveys. RESULTS The mean values of all 6200 exposures were 26.9 (±0.8) kVp, 130 (±30) mAs and 54 (±5) mm breast thickness and 2.6 (±0.5) mGy. The average of MGD for film/screen sites ranged 1.8 – 3.7 mGy whereas for the only digital site it was 1.6 mGy. Comparisons of the three dose calculation methods showed that estimates obtained from Dance data were 9% greater than those suggested by Wu and 19% greater than suggested by Boone. CONCLUSION Average patient MGD for the 31 screening site participated ranged from 1.6–3.7 mGy with lowest being a digital mammography site.