Jennifer Murphy MBBCh, MRCPI, Presenter: Nothing to Disclose

Siobhan O' Neill MBBCh, Abstract Co-Author: Nothing to Disclose

Fiachra Gerard Moloney MBBCh, MRCPI, Abstract Co-Author: Nothing to Disclose

Lorna Duddy MD, Abstract Co-Author: Nothing to Disclose

Nina Louise Marshall MBBS, Abstract Co-Author: Nothing to Disclose

Josephine Barry MBBCh, FRCR, Abstract Co-Author: Nothing to Disclose

Max Frederick Ryan MBBCh, Abstract Co-Author: Nothing to Disclose

The aim of this study is to evaluate the dose associated with contrast-enhanced spectral mammography (CESM) compared with full field digital mammography (FFDM) in a national breast cancer centre using web-based radiation dose tracking software and to investigate factors that affect this.

Fifty patients attending the Symptomatic Breast Clinic who underwent FFDM and CESM within a short interval were retrospectively identified. Average glandular dose (AGD) was calculated for FFDM, low energy CESM (LE-CESM) and high-energy CESM (HE-CESM). Compressed breast thickness was recorded. Breast density was measured using the American College of Radiology (ACR) Breast Imaging-Reporting and Data System (Bi-RADS) by two independent radiologists.

Fifty patients were included in the study (all female, mean age 54.3 ±13.2 years). The mean AGD for FFDM, LE-CESM and HE-CESM was 5.39 mGy, 7.78 mGy and 1.87 mGy respectively. LE-CESM was associated with a significantly higher dose than FFDM (mean difference 2.39 mGy, CI 1.82 – 2.96, p<0.0001). The AGD of CESM (LE-CESM and HE-CESM combined) was also significantly higher than that of FFDM (mean difference 3.69 mGy, CI 3.23 – 4.16, p<0.0001). There was no significant relationship between compressed breast thickness and the AGD of FFDM or CESM (p=0.679 and p=0.833 respectively). There was also no significant relationship between breast density and AGD of FFDM or CESM (p=0.66 and p=0.42 respectively).

CESM is a relatively novel technique. Studies have shown that it has a higher sensitivity for breast cancer than FFDM and better specificity than MRI. It is associated with increased dose when compared to FFDM however remains within accepted limits set out in ACR guidelines.

As LE-CESM is technically equivalent to FFDM, CESM could be used instead of FFDM to reduce overall dose in selected patients.

Murphy, J, O' Neill, S, Moloney, F, Duddy, L, Marshall, N, Barry, J, Ryan, M, Dose Evaluation of Contrast-enhanced Spectral Mammography in a National Cancer Centre.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14009672.html