A Novel High-resolution Dedicated Axillary PET Improve Sensitivity in the Assessment of Regional Nodal Spread of Disease in Early Breast Cancer.

Background: The aim of this study was to assess if a novel high-resolution dedicated axillary lymph node Positron Emission Tomography (LymphPET) system could improve sensitivity analysing Lymph Node involvement in early breast carcinoma with clinical N0-N1 stage. Methods: : A total of 103 patients with clinical stage of T1-2N0-1M0 breast cancer were evaluated with LymphPET. The maximum single-voxel PET uptake value of Axillary Lymph Node (maxLUV) and the tumor-to-background ratio (TBR) for fat (TBR1) and muscle (TBR2) tissue were calculated. Then, seventy-eight patients with cN0 stage received sentinel lymph node biopsy (SLNB) alone or in combination with ALN dissection (ALND) and 25 patients with cN1 stage underwent fine-needle aspiration (FNA). Results: : Ninety-nine invasive breast carcinoma entered this study. The diagnostic sensitivity of LymphPET was 87.80%, specificity was 79.31%, false-negative rate was 12.20%, false-positive rate was 20.69%, positive predictive value was 75.00%, negative predictive value was 90.20%, and accuracy was 82.83%. The maxLUV was superior to TBR1 and TBR2 in the detection of ALN, with 0.27 being the most optimal cutoff value. Conclusion: The 18 F-FDG LymphPET could be used to identify and recognize more indolent ALNs of the breast cancer because of more sensitivity and much higher negative predictive value.