Application of the Kaiser score in the assessment of suspicious contrast-enhancing lesions on breast MRI in patients with equivocal conventional imaging findings
Katarina Obradovic, Belgrade / Serbia
Author Block: K. Obradovic, I. Petkovic, D. Pavlovic Stankovic, V. Urban, Z. C. Milosevic; Belgrade/RSPurpose: To assess whether applying the Kaiser score might downgrade breast MRI BI-RADS categories in patients with equivocal conventional imaging findings (mammography and/or US) and avoid unnecessary biopsies.Methods or Background: Equivocal conventional imaging findings are one of the indications for problem-solving breast MRI. Generally, a combination of high sensitivity (98–100%) and suboptimal specificity (up to 88%) is inherent to breast MRI, which frequently results in false-positive diagnoses.Our single-centre study enrolled 61 consecutive patients from January 2017 to December 2018, with equivocal conventional imaging findings and 69 breast lesions on MRI (62 lesions in BI-RADS category 4, seven in BI-RADS category 5), undergoing US-CNB and/or surgery. All MRI examinations were re-evaluated after 4 years of the patients' follow-up, using the Kaiser score by two breast imaging radiologists and one radiology resident, individually and blinded to the pathological diagnosis and previous reading results, with the consensus about different opinions through consultation.Results or Findings: Histopathology revealed 18 malignant and 51 benign lesions, resulting in a predominance of benignancy of - 9%. The mean size of lesions on MRI was 15±10 mm; 50 lesions presented as masses (72.5%), 19 as a non-mass enhancement (27.5%), and there was no difference between malignant and benign lesions. The Kaiser score was as follows: 1–4 (BI-RADS 2/3) in 48 lesions (69.6%), 5–7 (BI-RADS 4) in 11 (15.9%), and 8–11 (BI-RADS 5) in ten (14.5%) (Figs. sensitivity and specificity were 100% and 94.1%, respectively, with three false-positive findings and no false-negative findings. The AUC was 0.971 (95% CI: 0.932–1.000).
Conclusion: Applying the Kaiser score to breast MRI, BI-RADS categories are reclassified (particularly BI-RADS 4 to BI-RADS 2/3), which can obviate unnecessary biopsies in breast lesions with equivocal conventional imaging findings.Limitations: No limitations were identified.Funding for this study: No funding was received for this study.Has your study been approved by an ethics committee? YesEthics committee - additional information: The study was approved by the Institute of Oncology and Radiology of Serbia: 1140-01