RADIATION PROTECTION IN DIAGNOSTIC AND INTERVENTIONAL RADIOLOGY Part No...., Module No....Lesson No Module title IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology RADIATION PROTECTION IN DIAGNOSTIC AND INTERVENTIONAL RADIOLOGY Part 19.05: Optimization of protection in Mammography Practical exercise Part …: (Add part number and title) Module…: (Add module number and title) Lesson …: (Add session number and title) Learning objectives: Upon completion of this lesson, the students will be able to: … . (Add a list of what the students are expected to learn or be able to do upon completion of the session) Activity: (Add the method used for presenting or conducting the lesson – lecture, demonstration, exercise, laboratory exercise, case study, simulation, etc.) Duration: (Add presentation time or duration of the session – hrs) Materials and equipment needed: (List materials and equipment needed to conduct the session, if appropriate) References: (List the references for the session) IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

Part No...., Module No....Lesson No Module title Overview To be able to apply quality control protocol to mammography equipment To measure the Half Value Layer Interpretation of results Explanation or/and additional information Instructions for the lecturer/trainer 19.05 : Optimization of protection in Mammography IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

Part 19.05: Optimization of protection in Mammography Part No...., Module No....Lesson No Module title IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology Part 19.05: Optimization of protection in Mammography Beam quality (HVL) Part …: (Add part number and title) Module…: (Add module number and title) Lesson …: (Add session number and title) Learning objectives: Upon completion of this lesson, the students will be able to: … . (Add a list of what the students are expected to learn or be able to do upon completion of the session) Activity: (Add the method used for presenting or conducting the lesson – lecture, demonstration, exercise, laboratory exercise, case study, simulation, etc.) Duration: (Add presentation time or duration of the session – hrs) Materials and equipment needed: (List materials and equipment needed to conduct the session, if appropriate) References: (List the references for the session) IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

Half value layer (HVL) The Half Value Layer (HVL) can be assessed by adding thin aluminium (Al) filters to the X-ray beam and measuring the attenuation Position the detector on top of the breast table Place the compression device halfway between focal spot and detector 19.05 : Optimization of protection in Mammography

Half value layer (HVL) Select 28 kV and an mAs to produce at least 10 mGy and make an exposure Position the aluminium filters on top of the compression paddle and assure that they intercept the entire radiation field. Use the same mAs setting and make an additional exposure after adding each filter 19.05 : Optimization of protection in Mammography

HVL Measurement Geometry X-Ray Tube Aluminium filter Diaphragm Compression paddle Detector Lead Breast support ~ 300 mm ~ 300 mm 19.05 : Optimization of protection in Mammography

Half value layer (HVL) For higher accuracy (about 2%) a diaphragm, positioned on the compression paddle, limiting the exposure to the area of the detector may be used The HVL is calculated by applying the formula: 19.05 : Optimization of protection in Mammography

Half value layer (HVL) Y0 : the direct exposure reading (mGy) Y1 and Y2 : the exposure with added aluminium thickness of X1 and X2 respectively Note 1: The purity of the aluminium must be 99.0% or greater. The thickness of the aluminium sheets should be measured to an accuracy of 1% 19.05 : Optimization of protection in Mammography

Half value layer (HVL) Note 2: For this measurement the output of the X-ray machine must be stable Note 3: The HVL for other (clinical) energies, and other target materials and filters should also be measured for assessment of the average glandular dose 19.05 : Optimization of protection in Mammography

Half value layer (HVL) Limiting value : For 28 kV Mo-Mo the HVL must be over 0.30 mm Al equivalent Frequency : Annually Equipment : Dosimeter, 99.0% aluminium sheets 0.20 and 0.40 mm 19.05 : Optimization of protection in Mammography

Where to Get More Information European protocol for the quality control of the physical and technical aspects of mammography screening. http://euref.org/index.php?option=com_phocadownload&view=category&id=1&Itemid=8 American College of Radiology Mammography Quality Control Manual, Reston VA, 1999. 15.3: Optimization of protection in radiography