Objective: To compare the diagnostic performance of breast magnetic resonance imaging (MRI) and mammography with ultrasonography for detection of local recurrent breast cancer among female patients with post-breast conserving therapy (BCT).

Materials and Methods: The authors retrospectively enrolled 190 post-BCT female patients who underwent post-operative surveillance by breast MRI and mammography with ultrasonography at King Chulalongkorn Memorial Hospital between January 1, 2008 and July 1, 2019. Two radiologists reviewed the images from the two surveillance modalities, independently. The information including radiological and histopathological data were blinded during the review process. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were then estimated to reflect the diagnostic performance of the two modalities for detection of local recurrent breast cancer.

Results: Of the 190 patients, 52 (27.4%) were diagnosed as local recurrent breast cancer. Sensitivity, specificity, PPV, and NPV were 98.1%, 92%, 82.3%, 99.2%, respectively, for breast MRI, and 88.5%, 62.3%, 46.9%, 93.5%, respectively, for mammography with ultrasonography. The findings that could be better evaluated by breast MRI than by mammography with ultrasonography included post-operative change and benign mass (p<0.001), suspicious mass (p<0.001), and suspicious calcification (p<0.003).

Conclusion: Breast MRI is superior to mammography with ultrasonography for detection of local recurrent breast cancer after BCT. Furthermore, MRI can help clinicians avoid unnecessary biopsy and surgical interventions due to its ability to differentiate post-treatment change from local recurrent breast cancer.

Keywords: Breast conserving therapy; Magnetic resonance imaging; Breast MRI; Mammography with ultrasonography; Local recurrent breast cancer

DOI: 10.35755/jmedassocthai.2023.04.13842

Received 8 August 2022 | Revised 27 February 2023 | Accepted 27 February 2023