乳癌フォローアップにおける造影マンモグラフィ：再発疑い症例における診断的価値

Women with a personal history of breast cancer (PHBC) are at increased risk of local recurrence or new primary tumors, which are often difficult to assess on conventional imaging because of postoperative changes. This prospective study aimed to evaluate the diagnostic performance of contrast-enhanced mammography (CEM) in women with PHBC presenting with suspicious findings on follow-up mammography or ultrasound. Sixty-two patients underwent CEM between December 2023 and June 2025. Lesions showing enhancement were biopsied, while non-enhancing ones were followed for stability. Histopathology served as the reference standard. Diagnostic performance was assessed using standard statistical methods, including sensitivity, specificity, Fisher's exact test, and ROC analysis. Among 62 lesions, 34 were enhanced on CEM; 30 of these (88.2%) were malignant, whereas 25 of 28 non-enhancing lesions (89.3%) were benign (p < 0.001). CEM demonstrated a sensitivity of 90.9%, specificity of 86.2%, and diagnostic accuracy of 88.7%. Interobserver agreement was substantial (κ = 0.76, p < 0.001). Enhancement on recombined CEM images was strongly associated with malignancy. These findings confirm that CEM provides excellent diagnostic performance in the surveillance of women with PHBC, effectively distinguishing benign from malignant postoperative changes. CEM may serve as a practical and accessible alternative to magnetic resonance imaging, particularly in patients with contraindications or where it is unavailable.