Mary M. Kelly MD, Presenter: Nothing to Disclose

Paula Shah Hallam MD, Abstract Co-Author: Nothing to Disclose

Jay R. Parikh MD, Abstract Co-Author: Nothing to Disclose

Kelly K Shaw MPH, Abstract Co-Author: Nothing to Disclose

Mobile digital mammography has the potential to increase the penetration of breast cancer screening among rural women. To assess possible efficacy differences in screening mammography by equipment and setting, we compared medical audit results of three different screening mammography paradigms at a single institution.

Between January 1 and December 31, 2004, 13,670 screening mammograms were performed by the Comprehensive Breast Center, Swedish Medical Center, Seattle, WA: Group A: 947 mammograms on digital equipment (Selenia, Hologic)in a medical coach taken throughout Western Washington; Group B: 6,408 film-screen mammograms using two analog machines (Sophie, PlanMed)moved by van to locations around the city; and Group C: 6,315 mammograms performed at the breast center with analog and digital equipment(LoRad MIV and Selenia, Hologic). All mammograms were performed by a single pool of technologists and were interpreted by the same group of radiologists with the aid of the same computer-aided detection system (R2). We compared the three groups for the following parameters: recall rates, BI-RADS assessment categories, positive predictive value for screening, number of cancers found, and cancer rate per 1,000. Because of the short follow-up period, we did not calculate sensitivity and specificity, false negatives being still potentially unknown.

Results for the mobile screening paradigms were very similar. Incidence of cancer and acuity of BI-RADS assessment codes were higher for women screened at the breast center than with mobile screening. Recall rates for all three groups were similar. Recall rates: Group A 18%; Group B 17%; and Group C 18%. Distribution of BI-RADS categories: BI-RADS 1: Group A 76%; Group B 79%; and Group C 72%. BI-RADS 2: 3%; 2.5%; and 8%. BI-RADS 3: 0.2%; 0.1%; and 4%. BI-RADS 4: 0.1%; 0%; and 3%. BI-RADS 5: 0.3%; 0%; and 0.03%. PPV (screening) was 2.2%, 2.5% and 6.3% respectively. Cancers found: Group A 4 (4.2 per 1,000); Group B 28(4.3 per 1,000); and Group C 40 (6.3 per 1,000).

Performance of mobile digital mammography is very similar to mobile film/screen mammography. Diffusion of digital technology for mobile screening seems appropriate.

M.M.K.,J.R.P.: Member of scientific advisory board for Hologic, Inc.

Kelly, M, Hallam, P, Parikh, J, Shaw, K, Comparison of Mobile Digital Mammography Screening with Both Mobile Analog Screening and Fixed-Site Digital and Analog Screening in a Single Institution: Is the Medical Audit Identical?.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4405578.html