@article {Morawitzjnumed.121.262009, author = {Janna Morawitz and Nils-Martin Bruckmann and Frederic Dietzel and Tim Ullrich and Ann-Kathrin Bittner and Oliver Hoffmann and Svjetlana Mohrmann and Lena Haeberle and Marc Ingenwerth and Lale Umutlu and Wolfgang Peter Fendler and Tanja Fehm and Ken Herrmann and Gerald Antoch and Lino Morris Sawicki and Julian Kirchner}, title = {Determining the axillary nodal status with four current imaging modalities including 18F-FDG PET/MRI in newly diagnosed breast cancer: A comparative study using histopathology as reference standard}, elocation-id = {jnumed.121.262009}, year = {2021}, doi = {10.2967/jnumed.121.262009}, publisher = {Society of Nuclear Medicine}, abstract = {Purpose: To compare breast magnetic resonance imaging (MRI), thoracal MRI, thoracal 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET)/MRI and axillary sonography for the detection of axillary lymph node metastases in women with newly diagnosed breast cancer. Materials and Methods: This prospective double-center study included patients with newly diagnosed breast cancer between March 2018 and December 2019. Patients underwent thoracal (18F-FDG PET/)MRI, axillary sonography, and dedicated prone breast MRI. Datasets were evaluated separately regarding nodal status (nodal+ vs. nodal-). Histopathology served as reference standard in all patients. The diagnostic performance of breast MRI, thoracal MRI, thoracal PET/MRI and axillary sonography in detecting nodal positive patients was tested by creating receiver-operating-characteristic curves (ROC) with a calculated area under the curve (AUC). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for all four modalities. A McNemar test was used to assess differences. Results: 112 female patients (mean age 53.04 {\textpm} 12.6 years) were evaluated. Thoracal PET/MRI showed the highest ROC-AUC with a value of 0.892. The AUC for breast MRI, thoracal MRI and sonography were 0.782, 0.814 and 0.834, respectively. Differences between thoracal PET/MRI and axillary sonography, thoracal MRI and breast MRI were statistically significant (PET/MRI vs. axillary sonography, P = 0.01; PET/MRI vs. thoracal MRI, P = 0.02; PET/MRI vs. breast MRI, P = 0.03). PET/MRI showed the highest sensitivity (81.8\%, 36/44) (95\%-CI: 67.29-91.81\%) while axillary sonography had the highest specificity (98.5\%, 65/66), 95\%-CI: 91.84-99.96\%). Conclusion: 18F-FDG PET/MRI outperforms axillary sonography, breast MRI and thoracal MRI in determining the axillary lymph node status. In a clinical setting, the combination of 18F-FDG PET/MRI and axillary sonography might be considered to provide even more accuracy in diagnosis.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/early/2021/05/20/jnumed.121.262009}, eprint = {https://jnm.snmjournals.org/content/early/2021/05/20/jnumed.121.262009.full.pdf}, journal = {Journal of Nuclear Medicine} }