title: Phantoms for quality control procedures in digital breast tomosynthesis: dose assessment.
abstract: The recent introduction of digital breast tomosynthesis into clinical practice requires quality control procedures. In this study we have investigated whether the assessment of the average glandular dose for modelled standard breasts can be performed using a combination of polymethyl methacrylate (PMMA) and polyethylene (PE) slabs that matches standard breast thicknesses. For this purpose the energies absorbed per unit area of the image receptor when imaging standard breasts and PMMA-PE slabs have been matched taking account of both primary and scattered photons. To achieve this a two-step approach was used. Firstly, the behaviour of the scatter-to-primary ratio (SPR) of PMMA-PE phantoms and standard breasts was investigated using Monte Carlo simulations for various conditions. For imaging without an anti-scatter grid, it was found that the values of standard breast and phantom SPR were significantly different and it follows that these differences are relevant when matching the absorbed energy. In the second part, a set of PMMA-PE combinations is proposed which, for dosimetric purposes, can be used to simulate standard breasts in the thickness range 20 to 100 mm. The dosimetric error when using these PMMA-PE slabs was found to be below 6% for thicknesses up to 7 cm and increases to 10% for 10 cm thickness.
authors.affiliation: National Expert and Training Centre for Breast Cancer Screening, Radboud University Nijmegen Medical Centre (LRCB), Weg door Jonkerbos 90, 6532 SZ Nijmegen, The Netherlands. r.bouwman@lrcb.nl
authors.forename: R W
authors.initials: RW
authors.lastname: Bouwman
authors.forename: O
authors.initials: O
authors.lastname: Diaz
authors.forename: R E
authors.initials: RE
authors.lastname: van Engen
authors.forename: K C
authors.initials: KC
authors.lastname: Young
authors.forename: G J
authors.initials: GJ
authors.lastname: den Heeten
authors.forename: M J M
authors.initials: MJ
authors.lastname: Broeders
authors.forename: W J H
authors.initials: WJ
authors.lastname: Veldkamp
authors.forename: D R
authors.initials: DR
authors.lastname: Dance
mesh_terms: D001940:Breast / Q000528:radiation effects*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005060:Europe; D005260:Female; D006801:Humans; D008327:Mammography / Q000295:instrumentation* / Q000592:standards; D009928:Organ Specificity; D019047:Phantoms, Imaging; D011785:Quality Assurance, Health Care / Q000379:methods / Q000592:standards; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation* / Q000592:standards; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000592:standards