National quality standards in mammography have been established to ensure safe, reliable, and accurate breast imaging services are delivered at accredited and certified facilities. The Mammography Quality Standards Act regulates US facilities, while in Canada, the Canadian Association of Radiologists sets out mammography standards. In the European Union, the European Reference Organisation for Quality Assured Breast Screening and Diagnostic Services (EUREF) works in collaboration with other organizations to set standards. As these standards evolve, certified facilities are required to adapt and remain in compliance at all times.
Organized state, provincial and federal bodies have long established reporting standards for mammography that stipulate what information is to be reported and to whom, and how the equipment at facilities is certified and maintained.
In the United States, the Mammography Quality Standards Act (MQSA) is in place to ensure the consistent delivery of quality mammography services. These quality standards require facilities to secure initial accreditation from an FDA-recognized body; receive certification as meeting the standards set out; participate in annual inspections to confirm compliance with the standards; and prominently display their certificate.
In Canada, the Canadian Radiology Association’s Mammography Accreditation Program (MAP) is designed to ensure consistent delivery of quality mammography services through an accreditation process and established quality standards that are similar to those laid out in the MQSA.
Several activities are underway in the EU to support quality mammography services. EUREF works in partnership with other organizations to set out mammography guidelines, certify breast services and mammography equipment, and provide training and counsel. The European Society of Radiology (ESR) established the EuroSafe program as a driver to improve quality and safety in medical imaging. This program covers a wide variety of areas, including radiation exposure; equipment maintenance; appropriate use; and communications with patients.
While these quality standards already exist, recent legislative changes are now beginning to impact the imaging and reporting processes. Mammography facilities must now ensure compliance with both the quality standards and legislated reporting practices.
Breast density has historically sometimes been recorded but not reported to a woman or her physician. This gap in patient knowledge is narrowing, due to the enactment of legislation and the increasing awareness of the important role of breast density in determining cancer risk and adjunct screening, the institutional risk of litigation over missed cancers, and public demand for change.
At a public level, there is growing demand to inform women and their doctors of breast density. Individually, and in organized groups, advocates are calling on state and federal legislators to introduce into law the disclosure of breast density to women as part of their screening mammogram follow up.
Successful lobbying has resulted in more than two-thirds of the women in the United States being covered by state legislation that requires them to be informed of their breast density. There are also bills making their way through the legislative process in a number of other states. When all endorsed bills become law, nearly 80 per cent of US women will be covered. A US federal bill is also in consideration.
In Canada, a private member’s bill to increase awareness of density and screening was introduced in the legislature and received first reading in October 2010. Bill C-314 is currently before the Senate in second reading. Full details and status of the bill can be viewed on the Government of Canada’s legislation website.
Groups in other areas around the world have also shown interest in breast density inform legislation, including the European Union and Japan.
Mean Glandular X-Ray Dose
There is a drive in imaging to reduce radiation dose exposure, to the extent that ‘dose reduction’ has been identified as a mega trend in radiology. Dose reduction aims to achieve the best possible X-ray image, at the minimal dose for the patient. This approach is also known as ALARA, or As Low As Reasonably Achievable.
The recent implementation of dose specific legislation and directives has driven uptake of dose tracking and attempts to incorporate patient specific dose reporting. In the United States, several states have implemented measures to establish specific dose thresholds, and mandated dose reporting on patient records. If the thresholds are exceeded, it must also be reported to the state.
In the European Union, the new European Basic Safety Standards advocate the establishment and use of diagnostic reference levels. Additionally, the EuroSafe program sets out requirements for patient exposure, establishes reference levels for dose, supports the ALARA principle to achieve low-dose and quality image generation, and conducts professional education activities around radiation dose.
In the case of digital mammography, mean glandular X-ray dose exposure is a factor set out in mammography quality standards against which facilities are evaluated to maintain compliance and certification.
The concerns around dose exposure are relevant in breast screening, because breasts are composed of soft tissue and as such offer very low contrast, and because breast tissue is particularly sensitive to excessive radiation exposure. As a result a balance must be achieved so that high quality images are generated while at the same time minimizing X-ray dose exposure. This relates to concerns about individual women’s lifetime exposure to radiation.