Diagnostic performance of a novel high-resolution dedicated axillary PET system in the assessment of regional nodal spread of disease in early breast cancer

Abstract

Background: In early breast cancer, a non-invasive method with higher sensitivity and negative predictive value (NPV) is needed to identify and recognize more indolent axillary lymph nodes (ALNs). This study aimed to assess whether a novel high-resolution dedicated ALN positron emission tomography (LymphPET) system could improve sensitivity in detecting early breast cancer (clinical N0-N1 stage).Methods: A total of 103 patients with clinical stage T1-2N0-1M0 breast cancer were evaluated by 18 F-fluorodeoxyglucose ( 18 F-FDG) LymphPET. The maximum single-voxel PET uptake value of ALNs (maxLUV) and the tumor-to-background ratio (TBR) for fat (TBR1) and muscle (TBR2) tissue were calculated. Then, 78 patients with cN0 stage breast cancer received sentinel lymph node biopsy alone or combined with axillary lymph node dissection (ALND), and 25 patients with cN1 stage breast cancer underwent fine-needle aspiration.Results: A total of 99 invasive breast carcinoma cases were included in this study. The diagnostic sensitivity of LymphPET was 88%, specificity was 79%, false-negative rate was 12%, the false-positive rate was 21%, positive predictive value was 75%, NPV was 90%, and accuracy was 83%. The maxLUV was superior to TBR1 and TBR2 in detecting ALNs, with 0.27 being the most optimal cutoff value. Conclusions:The 18 F-FDG LymphPET system can be used to identify and recognize more indolent ALNs of breast cancer due to greater sensitivity and a much higher NPV.

Feasibility of sentinel lymph node biopsy omission after integration of 18F-FDG dedicated lymph node PET in early breast cancer: a prospective phase II trial

“…A possible explanation for this finding is that, currently, the whole-body 18 F-FDG PET/CT system typically yields reconstructed images with a resolution of 5-15 mm, depending on the injected dose, imaging time, post-reconstruction filtering, and intrinsic resolution of the scanner, thus decreasing the system's ability to detect small lesions (< 1 cm) and/or lesions with low tracer uptake 21 . According to our previous study, the spatial resolution of LymphPET is much higher than that of whole-body PET/CT, with 88% sensitivity and 79% specificity, and a maxLUV of 0.27 as the best cut-off value 10 . In our previous study, we developed a machine learning model integrating LymphPET and clinical characteristics for the prediction of axillary LN status in cT1-2N0-1M0 breast cancer.…”

“…Moreover, 3 1-cm diameter ROIs were located at the biceps brachii and ectopectoralis muscles (muscle background), and the mean value was denoted maxLUV muscle. According to our previous study, when the cut-off value of the maxLUV LN was set at 0.27 (as recommended by Youden’s index), the diagnostic sensitivity was 88%, and the NPV reached a maximum of 90%, which was the best cut-off value for identifying the most suitable indicator for detecting ALNs with LymphPET 10 .…”

“…According to our previous study, a novel high-resolution dedicated axillary lymph node (LN) PET (LymphPET) method can be used to identify and recognize more indolent axillary LNs in breast cancer, given its greater sensitivity than other methods and its NPV of 90% 10 . Hence, we conducted a prospective phase II study to investigate the NPV of LymphPET and to verify whether SLNB might be omitted in cN0 patients (SOAPET, NCT04072653).…”

“…positive and HER2 positive 23 (12.2) HR negative and HER2 positive 27 (14.3)HR negative and HER2 negative 19(10) …”

Development of High-Resolution Dedicated PET-Based Radiomics Machine Learning Model to Predict Axillary Lymph Node Status in Early-Stage Breast Cancer

“…The highest SUVmax was selected as the study value when multiple lymph nodes were detected. The SUVmax cutoff value of lymph node on Lymph-PET was set at 0.27 according to a previous study [ 11 ]. SUVmax of ≥0.27 was considered positive, while that of <0.27 was considered negative.…”