PhD Title: Improving QA/QC in mammography screening and breast in Montenegro

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1 3rd Doctoral Coordinated Research Project (CRP) on Advances in medical imaging techniques (E ) MNE BEL PhD Title: Improving QA/QC in mammography screening and breast in Montenegro MNE BEL PhD Candidate: Sonja Ivanovic, Clinical centre of MNE, Podgorica, Montenegro Local mentor: prof. Slavoljub Mijovic, :Faculty of Natural Sciences and Mathematics, University of MNE, Podgorica, Montenegro Remote mentor: prof. Hilde Bosmans, Katholieke Universiteit Leuven, Belgium

2 Background: donation of 13 screen film units to public health care centers ( more than 15 years ago + 2 even older) 1 CR mammography system in the Clinical center of Montenegro 1 digital mammographic system with tomosynthesis and stereotactic biopsy, thanks to the national project TC MNE IAEA (CcoM) 2 new screen film systems at Health Care center Podgorica (starting these days) QC : yearly by 2 TSO (limited possibilities for QC, lack of equipment) Regulations older than 20 years, almost nothing about QC on diagnostic equipments

3 the single most important diagnostic tool in the early detection of breast cancer screening can reduce the breast cancer mortality with 30% if next to screening also proper diagnosis and treatment is offered investigating large population of women relationship radiation risk diagnostic accuracy must be optimized Image quality should be linked with specific medical tasks a good visibility of micro calcifications and small masses in the breast glandular tissue is required QC is necessary Through this PhD: to evaluate the technical situation of the Montenegrin mammography systems: to improve methods for evaluation of average glandular dose (AGD) and image quality; to establish national dose reference levels from data acquired according intl. standard procedures; to verify reliability of automated filter measurements with the MagicMax dosimeter;

4 Calculated AGD (D) for all screen film units compared with limiting values of the EU protocol

5 Diagnostic Reference Levels (DRL) S F dose levels expected not to be exceeded for standard procedures when good and normal practice regarding diagnostic and technical performance is applied (Council of EU) publication of values to be used = a task for the authorities in all EU Member States our input: Thickness PMMA (mm) Eqv.breast thickness (mm) Mean doses (mgy)

6 IMAGE QUALITY Optical density S F

7 CR system

8 Image quality assessed with the anthropomorphic phantom Mammo AT

9 Testing of new DBT system D = KgcsT Mean Glandular Dose (MGD) for DBT is slightly higher than for 2D mode. There are no limiting values for DBT MGD currently but the MGD values are within Reference values given for 2D in the EUREF protocol

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14 Uncertainties in Half Value Layer Determination in Mammography - most important input parameter for patient-dose estimation in mammography - defined as the absorber material thickness necessary to reduce x - ray beam intensity to half of its incident value different solid state dosimeters with ability to obtain the HVL value with a single x ray exposure Research question: can these single shot measurements be trusted? The traditional method of deriving HVL by using a set of, usually, seven pure Al sheets of 0.1mm of thickness was conducted Air kerma was measured versus the thickness of Al barrier, placed between the X ray source and detector The study was performed on different mammography units Three different calibrated solid state detectors and one ionization chamber were used

15 The experimental data were then fitted with an exponential function, using MATLAB curve fitting toolbox, f (x)= a exp( bx) mmal all experimental data fitted well to an exponential function (correlation coefficients were in the most cases more than 99%) Remaining task: the effect of less input points and ultimately the new single shot approach

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