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

Aim. To assess the diagnostic accuracy of Contrast Enhanced Spectral Mammography (CESM), and gauge its “added value” in the symptomatic setting. Methods. At our institution, women aged 35-70 years with a suspicious or malignant clinical abnormality are offered CESM instead of standard Full-Field Digital Mammography (FFDM) as an initial imaging test. CESM is also offered to younger women whose ultrasound is suspicious, or who have biopsy-proven malignancy. It is occasionally used as an alternative to breast MRI following multi-disciplinary team discussion. We performed a retrospective multi-reader review of 100 consecutive CESM examinations. 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. Pathology data was obtained for all cases. Differences in performance were assessed using receiver operative characteristic (ROC) analysis. Sensitivity, specificity and lesion size (vs MRI or histopathology) differences were calculated. Results. 73% 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 93% vs 83% (p<0.025). CESM showed increased sensitivity (95% vs 84, p<0.025) and specificity (81% vs 63%, p<0.025) compared to LE alone, with all 5 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.