Accuracy of positron emission mammography for tumor size assessment and detection of other breast lesions in newly diagnosed breast cancer

Abstract Background Positron emission mammography (PEM) is a valuable tool for assessing the extent of disease in newly diagnosed breast cancer patients, particularly among women pursuing conservative surgical management. The aim of this study was to evaluate the added diagnostic value of preoperative Positron Emission Mammography (PEM) in detecting tumor multiplicity and accurately assessing tumor size. Methods Seventy-seven patients (80 pathologically proven malignant breast lesions) were included in this cross-sectional, single-site study. All cases underwent PEM in addition to standard diagnostic Sono-mammography (SM), core biopsy, and surgery. Maximum PEM uptake value (PUV max) and lesion-to-background ratio (LTB) values were calculated for each lesion. Results In 77 patients with 80 malignant breast lesions, positron emission mammography (PEM) demonstrated almost perfect agreement with post-operative pathology in assessing tumor multiplicity (κ = 0.827, P < 0.001), significantly outperforming sono-mammography (κ = 0.401, P < 0.001). PEM led to changes in surgical management by accurately distinguishing unifocal, multifocal, and multicentric disease, facilitating appropriate selection between breast-conserving surgery and modified radical mastectomy. PEM also showed substantial agreement with pathology in lesion size assessment (ICC = 0.724, P < 0.001), compared with fair agreement for sono-mammography (ICC = 0.275, P = 0.006). Conclusion PEM is a sensitive and specific imaging modality for diagnosing breast cancer. It also demonstrated good agreement in detecting tumor multiplicity and estimating precise tumor size; therefore, its use prior to surgery should be considered. Clinical relevance/application PEM is a problem-solving tool in the pre-operative local staging of breast cancer in patients with contraindications to undergo MRI.