The radiation metrology network related to the field of mammography: implementation and uncertainty analysis of the calibration system

It is recognized by the international guidelines that it is necessary to of fer calibration services for mammography beams in order to improve the qual ity of clinical diagnosis. Major efforts have been made by several laborato ries in order to establish an appropriate and traceable calibration infrast ructure and to provide the basis for a quality control programme in mammogr aphy. The contribution of the radiation. metrology network to the users of mammography is reviewed in this work. Also steps required for the implement ation of a mammography calibration system using a constant potential x-ray and a clinical mammography x-ray machine are presented. The various qualiti es of mammography radiation discussed in this work are in accordance with t he IEC 61674 and the AAPM recommendations. They are at present available at several primary standard dosimetry laboratories (PSDLs), namely the PTB, N IST and BEV and a few secondary standard dosimetry laboratories (SSDLs) suc h as at the University of Wisconsin and at the IAEA's SSDL. We discuss the uncertainties involved in all steps of the calibration chain in accord with the ISO recommendations.