Quality control in mammography: an initiative in France

The ultimate effectiveness of any mass screening campaign is directly related to strict compliance with certain rules and technical protocols designed for radiological installations. Concerning radiological screening, the primary technical objective is to ensure reproducibly high quality images at low radiation dose to the patient. This paper describes the methodology followed for the implementation of a quality control (QC) programme of 48 mammography installations used within the context of the breast cancer screening campaign in the Bas-Rhin region of eastern France. In order to demonstrate the efficacy of such a programme, results of QC tests and procedures relating to each element of the radiological imaging chain are presented and compared for four control visits carried out at 6 month intervals over a period of 2 years. A reduction of 50% (from 16 mGy to 7.5 mGy) of breast entrance doses (normalized to a breast thickness of 4.5 cm) and a significant improvement of detectability of high contrast details are discussed. The importance of encouraging an extension of a similar process to the other screening experiments currently underway in France is emphasized.