Congress:
EuroSafe Imaging 2021
Keywords:
Breast, Contrast agents, Radioprotection / Radiation dose, Mammography, Contrast agent-intravenous, Dosimetry, Radiation safety, Cancer, Multidisciplinary cancer care, Quality assurance
Authors:
E. M. L. Vaccara, N. Brunetti, M. Calabrese, A. Garlaschi, L. Ridolfi, G. Pellecchia, M. Dordolo, C. Gavotti, F. Levrero
DOI:
10.26044/esi2021/ESI-13005
Results or findings
Based on our Poly Methyl MethAcrylate (PMMA) measurements, the dose limits would be respected even if we did an FFDM before the injection and a CEDM after the injection. In fact, the EUREF dose limits are perfectly respected for all thicknesses investigated, as can be seen in the figure.
A very interesting thing is that the dose increase compared to conventional mammography (FFDM) is not only due to the double exposure (high energy contributes only 25%), but to the low energy exposure which alone leads to a dose increase ranging from 20% to 80% depending on the thickness (26% in the reference thickness of 45mm of PMMA). To better understand the magnitude of the dose increase in CEDM, we have plotted the contributions of high and low energy CEDM normalized respecting to the FFDM dose.
The overall CEDM dose, normalized respecting to FFDM, ranges from 160% for low thicknesses to 246% for larger ones.
Having met the prerequisites of image quality, dosimetric accuracy and complied with the EUREF dose limits, the collection of clinical data could begin.
We are classifying in terms of age/density/thickness the first patients enrolled in CEDM and we are collecting the manufacturer dosimetric data to cross-correlate them and evaluate the risk/benefit balance of this specific Protocol.
In particular, the patients were divided into four breast density classes, following the fifth edition of BI-RADS (Breast Imaging-Reporting And Data System). Breast density refers to the amount of fibro-glandular tissue in a breast relative to fat. It can significantly vary between individuals and within individuals over a lifetime. We note each patient's density class at enrolment.
All enrolled patients have a confirmed disease diagnosis and at the moment belonging only to class "a" or "b" of the BI-RADS classification.
We analysed the manufacturer dose values of the CEDM double projections by dividing them into classes of compressed breast thickness, the trend is shown in the figure, where the bubble size is proportional to the standard deviation of AGD for each class.