Review of radiation dose estimates in digital breast tomosynthesis relative to those in two-view full-field digital mammography

Abstract

We examined how radiation dose levels in digital breast tomosynthesis (DBT) differ from those used in 2-view full-field digital mammography (FFDM). Acquisition parameter settings and information on the average absorbed dose to the glandular tissues within the breasts were reviewed based on clinical studies that evaluated DBT and FFDM. Dose ratios (DDBT/DFFDM) were derived from imaging protocols, which included tomosynthesis in 1- or 2-views alone, and as an adjunct technique to FFDM. Stand-alone DBT was associated with a much lower to a slightly higher radiation dose compared to that of comparable FFDM units, as summarized in dose ratio ranges of 0.34–1.0 for 1-view DBT, and 0.68 –1.17 for 2-view DBT. One of the lowest reported dose estimates was obtained using a photon-counting DBT unit (avg. 0.70 mGy/scan; range: 0.28–1.26 mGy). Breast doses for DBT combined with FFDM are summarized in dose ratio ranges of 1.03–1.5 for 1-view DBT plus FFDM, and 2.0–2.23 for 2-view DBT plus FFDM. In the latter of these settings, the dose was reduced by ∼45% when 2D-views, reconstructed from the DBT images (“synthetic 2D images”), were used as a substitute for FFDM. Stand-alone DBT operated at lower to slightly higher radiation doses in comparison to FFDM. For DBT combined with FFDM, radiation doses were elevated, at maximum by a factor ∼2 1/4 of that of FFDM alone. In this setting, a replacement of FFDM with synthetic 2D-views reduced the breast dose approximately by half, which has substantial implications for population screening programs.

Breast composition: Measurement and clinical use

“…The high detector quantum efficiency (DQE), fast read-out ability, and low noise levels of digital detectors used in DBT have enabled acquisition of good quality images at low doses in dense breasts. 43 DBT produces pseudo-cross-sectional images that reduce tissue superimposition and synthetic (reconstructed) 2-dimensional (2D) images which can be used as substitute for standard 2D images of digital mammography. The combined use of 3D images of DBT and standard 2D images of digital mammography (DM) has been shown to improve diagnostic accuracy, 44,45 but is associated with increased radiation dose.…”

“…The combined use of 3D images of DBT and standard 2D images of digital mammography (DM) has been shown to improve diagnostic accuracy, 44,45 but is associated with increased radiation dose. 43 However, use of reconstructed 2D images as substitute for standard 2D images has been found to be associated with a 45% reduction in mean glandular dose. 43,46 Mechanisms linking breast density to breast cancer Two theories have been postulated to explain the mechanisms linking breast density and breast cancer.…”

“…43 However, use of reconstructed 2D images as substitute for standard 2D images has been found to be associated with a 45% reduction in mean glandular dose. 43,46 Mechanisms linking breast density to breast cancer Two theories have been postulated to explain the mechanisms linking breast density and breast cancer. The first mechanism involves mitogen (a chemical substance that encourages a cell to commence cell division, triggering mitosis), 47 and mutagen effects (a physical or chemical agent that changes the genetic material of an organism and thus increases the frequency of mutations above the natural background level).…”

“…148,149 Studies have reported 7.2% -53% increase in cancer detection and 20% -59% reduction in recall rates with supplemental DBT. 31,44,45,150,151 Importantly, radiation dose to the dense tissue is lower for DBT than digital mammography (DM) for dense breasts; 43 therefore DBT is preferable to DM in terms of performance and dose, albeit it appears women with fatty breasts get higher dose on DBT. 152 Another approach suitable for imaging the dense breast is molecular breast imaging (MBI) or BreastSpecific Gamma Imaging (BSGI).…”

Evaluation of Agd in Digital Breast Tomosynthesis Relative to Those in Two-View-Full-Field Digital Mammography.

“…DBT allows the detection of a greater number of expansion lesions and a better morphological analysis of masses and architectural distortions [7] . Advanced system facilitates the DBT along with two view Full Field Digital mammography (FFDM) [8] [9] . Therefore the purpose of the study was to compare the Average Glandular Dose (AGD) of DBT and FFDM and to calculate the percentage of radiation dose reduction when using DBT with compare to FFDM .…”