Contrast-enhanced spectral mammography for breast cancer

The technologies described in this briefing are 4 systems for contrast-enhanced spectral mammography (CESM). They are used for enhanced mammography imaging where certain types of breast cancer may be easier to see, compared with standard mammography. These technologies can be useful in people with dense breast tissue.

The innovative aspects are that a contrast agent is used, and 2 X‑ray images of different energy are taken. The system software produces a final image, which enhances areas of the mammography image that can indicate cancer.

The intended place in therapy would be in clinics for people with suspected breast cancer, or to help plan treatment in people with confirmed breast cancer. It could be used instead of, or alongside, other types of imaging, such as contrast-enhanced MRI, ultrasound, full-field digital mammography or digital breast tomosynthesis.

The main points from the evidence summarised in this briefing are from 7 diagnostic accuracy studies (including 1 from the UK), and 3 cohort studies, including a total of 1,809 women with known or suspected breast cancer. Indirect comparisons with histopathology show that the performance of CESM is comparable with other imaging techniques in women with known or suspected breast cancer.

Key uncertainties around the evidence or technology are that diagnostic accuracy studies compare imaging with histopathology, and not directly with other imaging techniques. There is also a lack of prospective, comparative studies reporting on longer-term patient outcomes.

Six clinical experts advised that the technology could replace MRI, and people are likely to benefit from fewer hospital appointments, a more comfortable experience, shorter waiting times and quicker diagnosis.

Two patient and public involvement organisations advised that a quicker diagnosis could reduce patient stress and anxiety. They advised that people may be concerned about side effects from contrast injection or increased radiation exposure, and should have the option of other imaging techniques. They also noted an increased radiation dose and possible kidney complications with the contrast agent, concerns around lack of long-term follow up for surgical treatment planning, and potential overtreatment based on CESM results.

The cost to upgrade an existing mammography machine to use CESM software varies between £40,000 and £90,000. Servicing and maintenance are included in either the initial upgrade cost or existing service contract, or cost up to £19,000 per year. Potential barriers to adoption include workforce shortages (additional staff time needed for contrast injection and providing patient information) and capital cost, which could lead to varied provision across the NHS.