Elsevier

Clinical Radiology

Volume 71, Issue 11, November 2016, Pages 1148-1155
Clinical Radiology

Contrast-enhanced spectral mammography improves diagnostic accuracy in the symptomatic setting

https://doi.org/10.1016/j.crad.2016.05.009Get rights and content

Highlights

  • Contrast Enhanced Spectral Mammography (CESM) is a new breast imaging technique.

  • This retrospective multi-reader review compared low energy images alone to CESM.

  • Sensitivity, specificity and size accuracy were significantly improved with CESM.

  • In 75% of cases CESM was deemed a useful or significant aid to diagnosis.

  • CESM provides immediate and clinically useful information in the symptomatic clinic.

Aim

To assess the diagnostic accuracy of contrast-enhanced spectral mammography (CESM), and gauge its “added value” in the symptomatic setting.

Materials and methods

A retrospective multi-reader review of 100 consecutive CESM examinations was performed. Anonymised low-energy (LE) images were reviewed and given a score for malignancy. At least 3 weeks later, the entire examination (LE and recombined images) was reviewed. Histopathology data were obtained for all cases. Differences in performance were assessed using receiver operator characteristic (ROC) analysis. Sensitivity, specificity, and lesion size (versus MRI or histopathology) differences were calculated.

Results

Seventy-three percent of cases were malignant at final histology, 27% were benign following standard triple assessment. ROC analysis showed improved overall performance of CESM over LE alone, with area under the curve of 0.93 versus 0.83 (p<0.025). CESM showed increased sensitivity (95% versus 84%, p<0.025) and specificity (81% versus 63%, p<0.025) compared to LE alone, with all five readers showing improved accuracy. Tumour size estimation at CESM was significantly more accurate than LE alone, the latter tending to undersize lesions. In 75% of cases, CESM was deemed a useful or significant aid to diagnosis.

Conclusion

CESM provides immediately available, clinically useful information in the symptomatic clinic in patients with suspicious palpable abnormalities. Radiologist sensitivity, specificity, and size accuracy for breast cancer detection and staging are all improved using CESM as the primary mammographic investigation.

Introduction

The diagnostic assessment of patients with breast symptoms is based on the multidisciplinary triple diagnostic method. This includes clinical assessment, imaging assessment, and (where appropriate) needle biopsy.1 Mammography is the initial investigation of choice in women over the age of 40 years, and is also recommended in the assessment of younger women if clinically suspicious or malignant.

Mammography has its limitations, particularly in the younger woman, with denser breasts, where sensitivity is reduced.2 Contrast-enhanced spectral mammography (CESM) is a novel technique combining the benefits of iodinated contrast medium with standard mammographic views. Dual-energy acquisitions during one mammographic exposure yield two sets of images: a low-energy (LE) set, equivalent to standard full-field digital mammography (FFDM)3, 4, 5 and a recombined set displaying contrast uptake. Despite encouraging data from Europe and North America demonstrating increased sensitivity and specificity of the technique over FFDM,3, 6, 7 there are only limited data to support its routine use as a tool in the diagnosis and staging of breast cancer.

Accurate local staging of breast cancer is important for treatment planning and prognostication. With the increase in availability of oncoplastic techniques, the demonstration of multifocal or multicentric disease means that patients previously advised to undergo mastectomy may now be offered breast-conserving surgery. Larger tumours, previously warranting mastectomy, may be suitable for breast-conserving surgery post-neoadjuvant chemotherapy (NAC). Knowing the size and location of tumour foci aids surgical planning.

The aim of the present study was to assess the diagnostic accuracy of CESM, and to assess its “added value” in the symptomatic setting.

Section snippets

Materials and methods

Since November 2013, CESM has routinely been performed in the symptomatic breast service at Nottingham Breast Institute, according to local departmental guidelines. The technique was introduced following formal application (including literature review) to the local New Techologies Committee. Patients were made aware that the technology was new and were provided with an information sheet prior to giving written consent. The CESM examination was performed on a commercially available system

Results

Between November 2013 and September 2014, 100 CESM examinations were performed in 99 female individuals. Ninety-eight examinations were bilateral. One patient underwent unilateral CESM due to a previous mastectomy. One patient had previously had a reaction to gadolinium at baseline MRI and so underwent unilateral CESM to assess residual tumour size post-NAC in addition to the bilateral CESM examination performed at the time of diagnosis.

The mean age of the patient group at the time of CESM was

Discussion

In the present study, the routine use of CESM as the first-line mammographic technique for a symptomatic patient population with clinically suspicious abnormalities led to a significant improvement in diagnostic accuracy. Other groups have also recognised the value of CESM in cancer detection. Several studies have demonstrated consistent superiority of CESM when compared to FFDM.9, 10, 11, 12 Cheung et al.10 reported 89 women undergoing both CESM and conventional mammography. They concluded

Acknowledgements

The authors thank Mrs Laura Willoughby (Education Administrator) for data entry and support.

References (19)

There are more references available in the full text version of this article.

Cited by (0)

View full text