Advice
The technology
The technology
Contrast-enhanced spectral mammography (CESM) is a technique that combines mammography with contrast enhancement to show breast cancers that may not be visible on standard mammography. An iodine-based contrast agent is injected through a vein in the arm. After allowing the contrast to travel to the person's breast, the breast is compressed to hold it still. Two images are then taken using low- and high-energy X‑rays. The low-energy image is identical to a full-field digital mammography (FFDM) image. However, in the high-energy image, the higher-energy X‑rays are absorbed more strongly by the iodine, and areas with more contrast agent will be enhanced. The system software processes the 2 images to remove non-enhanced areas. The radiologist, or trained radiographer interpreting the image, will use the enhanced areas associated with abnormal blood vessels to identify potential cancers.
This briefing focuses on 4 technologies capable of CESM: Senographe Pristina (GE Healthcare), 3Dimensions (Hologic), AMULET Innovality (Fujifilm) and MAMMOMAT Revelation (Siemens). Other technologies may be available but are not included in this briefing. Reasons for this include not being commercially available to the NHS at the time of horizon scanning, or the company choosing not to take part.
All of the included technologies produce X‑rays for the high-energy image with a maximum tube voltage of 49 kV. Senographe Pristina, 3Dimensions and AMULET Innovality use a copper filter to remove lower-energy X‑rays. MAMMOMAT Revelation uses a titanium filter for this, and is referred to as titanium contrast-enhanced mammography (TiCEM), but is equivalent to the other CESM technologies. All technologies offer both automatic and manual exposure control. All technologies are also capable of 2D FFDM and 3D digital breast tomosynthesis (DBT).
Each technology has its own software for CESM, such that it is not compatible, or available for use, with other CESM mammography machines:
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Senographe Pristina: SenoBright, current version: CESM HD (2017)
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3Dimensions: I‑View, current version: 2.0 (2019)
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AMULET Innovality: CEDM Software, current version: available within system software version 9.2 and above (2019)
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MAMMOMAT Revelation: VC20, current version: VC20D (2021), from October 2022 VC20F.
CESM would be contraindicated in people with an allergy to iodinated contrast media. There are no further contraindications for use specifically relating to CESM for 3Dimensions or AMULET Innovality. Senographe Pristina and MAMMOMAT Revelation are not recommended for CESM in people with breast implants.
Innovations
The innovative aspect of CESM is that it may be easier to spot cancer, because there is better contrast between suspicious areas, with increased blood flow, and normal breast tissue. For people who might have otherwise had an MRI scan, imaging with these technologies will be quicker and may be completed at the breast clinic, instead of in the radiology department (Cancer Research UK, 2020). This could release time and resources for MRI in other areas.
Current care pathway
People with suspected breast cancer are usually invited to a breast clinic, where more tests can be done. These might include standard mammography imaging, ultrasound, biopsy and clinical examination. People with symptoms who are referred by their GP may have different tests than those people referred through the NHS breast screening programme, because they will have already had recent 2‑view mammography of both breasts. MRI might also be used as a further test, but this usually takes place in a radiology department, and so might not be available at the same time or in the same location. One of the experts commented that some people may also need a further visit to the breast clinic after MRI, for more investigations or biopsies. CESM could also be used to help plan treatment, or assess response to treatment, in people with confirmed breast cancer.
The following publications have been identified as relevant to this care pathway, providing guidance on breast imaging:
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The Royal College of Radiologists guidance on screening and symptomatic breast imaging refers to a 'triple assessment' including clinical assessment, imaging and needle biopsy, for people with symptoms of breast cancer. The guidance states that DBT or CESM can be used as an option for diagnostic imaging, instead of mammography, in those with suspicious findings on clinical examination. This may include younger women, who are more likely to have dense breasts, in which mammography has a decreased sensitivity (Sogani et al. 2021).
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The Association of Breast Surgery guidelines for the management of symptomatic breast disease includes the 'triple assessment' and makes recommendations for imaging, including that imaging standards should meet the same standards as for breast screening.
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The Royal College of Pathologists guidelines for non-operative diagnostic procedures and reporting in breast cancer screening give guidance on the use of image-guided biopsies.
Population, setting and intended user
CESM would be used in clinics for people with suspected breast cancer. This may include people who have been referred by their GP with symptoms, or people who have been recalled after screening. Two experts have stated that CESM is not currently approved by the NHS breast screening programme. The technologies could also be used to assess the extent of disease, or to help plan treatment in people with confirmed breast cancer. Four of 6 experts noted the likely setting of CESM to be district general hospitals. The CESM examination can be done by any radiographer trained in mammography, but a healthcare professional trained to insert the cannula and recognise contrast reactions is also needed. This may be the radiographer or a doctor.
Costs
Technology costs
The cost to upgrade an existing mammography machine for CESM ranges between £40,000 and £90,000. This does not include the initial purchase of the mammography machine, which can be used for standard mammography without CESM enabled. Each company provides training on its CESM technology free of charge. Servicing and maintenance are included in either the initial upgrade cost or existing service contract, or cost up to £19,000 per year.
The contrast can be injected by hand or powered pump, but the former might be more time consuming. There will be additional costs for the contrast agents used, and for equipment and consumables used for the injection. These are not provided with the CESM technology, and would also require separate training, maintenance and calibration.
One clinical expert estimated the cost of using CESM to be £82.88 per patient, which includes £64.62 for a standard mammogram, £9.37 for a single-use syringe and lines, and £8.89 for the contrast agent and cannulation. This does not include the software upgrade cost, or the cost of a powered contrast pump.
Costs of standard care
People with symptoms may have breast ultrasound, FFDM or MRI depending on the referral route, clinical indication or suspicion of breast cancer. The use of unbundled healthcare resource group (HRG) codes, variations in setting and the use of contrast agent, make it difficult to establish total imaging costs per patient. Unbundled HRG codes for ultrasound, FFDM and MRI range between £32.82 (RD40Z: ultrasound scan without contrast, with a duration of less than 20 minutes) and £211.33 (RD03Z: MRI scan of 1 area, with pre- and post-contrast). Based on clinical experience, a clinical expert estimated the cost of a standard mammogram to be £64.62 per patient, and the cost of MRI to be £150 per patient.
One clinical expert considered that most people with symptoms attending a breast clinic would have an ultrasound scan, people older than 40 years would also have mammography, and less than 1% would have breast MRI. People recalled from screening would have further mammography, with either additional views or DBT. The external assessment group (EAG) was unable to identify an unbundled HRG code specific to DBT; however, 1 clinical expert noted that the cost of CESM is comparable with DBT. Three experts noted that CESM is likely to be cheaper than dynamic contrast-enhanced imaging (MRI, tomosynthesis or mammography) and 4 experts also noted CESM is likely to be less costly or more cost effective than MRI.
Resource consequences
The CESM technologies are used in the NHS to help diagnose suspected or confirmed breast cancer. Senographe Pristina (GE Healthcare) is currently used for CESM in 11 NHS trusts. 3Dimensions (Hologic) is currently used in 9 NHS trusts. AMULET Innovality (Fujifilm) is currently used in 1 NHS trust. MAMMOMAT Revelation (Siemens) is currently used in 6 NHS trusts.
Other trusts have mammography machines with CESM technology enabled, but are not using it routinely, including 28 with the Senographe Pristina. More NHS trusts are likely to have the mammography machines available, and could upgrade them to use CESM. One clinical expert noted that most newly purchased machines have the dual-energy capability needed to conduct CESM.
NHS trusts may train existing staff conducting mammography services to use the technology; however, training and ongoing support may be needed. All 6 experts noted the additional staff training needed to handle contrast agents, cannulate people or use a powered injection pump. Although allergic reactions to iodinated contrast agents are rare (occurring in less than 1% of cases as estimated by 2 clinical experts), medical staff would also need to be available to treat the patient if a reaction did happen.
CESM will also take more time and resources than FFDM to collect the images. Patient and public involvement groups have advised that adoption of CESM may need additional appointment time to inform people of the steps involved and the benefits of CESM compared with standard care. However, all 6 clinical experts noted that CESM had the potential to reduce the need for, and waiting times related to, MRI. One expert also commented that CESM-guided biopsy could potentially be an alternative to MRI-guided biopsy, which could release additional MRI resources.