Early SUV max is the best predictor of axillary lymph node metastasis in stage III breast cancers

[摘要] Background: Although fluorine-18-labeled 2-fluoro-2-deoxy-D-glucose ( 18 F-FDG) positron emission/computed tomography (PET/CT) imaging has been investigated for its ability to evaluate lymph node metastasis of breast cancer, few comparative analyses have evaluated the preoperative and postoperative regional lymph node metastasis of breast cancer by dual-phase imaging, especially in patients with stage III (N2) disease. Methods: The clinical, pathological, and imaging data of 40 patients with stage III (N2) breast cancer were retrospectively analyzed. All patients underwent dual-time point 18 F-FDG imaging before surgery and postoperative pathology examinations were obtained. The short-axis lymph node diameter was measured, and the maximum standardized uptake value (SUV max ) and the percentage difference of SUV max between dual-phase (ΔSUV max ) were calculated to compare metastatic and non-metastatic lymph nodes on dual-time point images. Results: A total of 398 axillary lymph nodes were inspected, and 209 lymph nodes were matched with those on PET/CT images, including 97 metastatic and 112 non-metastatic lymph nodes. The SUV max values were significantly different between metastatic and non-metastatic lymph nodes, in both the early and delayed scans (P4.00 and ≤6.00 mm were not significantly different between the early and delayed scans (P=0.06). However, the SUV max values of metastatic lymph nodes with short diameters of >6.00 and ≤8.00 mm (7.11±0.19 vs . 5.96±0.08) and short diameters of >8.00 and ≤10.00 mm (10.76±0.35 vs . 6.82±0.50) were higher on the delayed scan versus the early scan, respectively (P<0.01 for each comparison). The difference between the ΔSUV max values among the three subgroups was statistically significant (F=78.98, P<0.001).The receiver operating characteristic (ROC) curve analysis of the lymph nodes showed that the area under the curve (AUC) of the early and delayed PET/CT scans was 0.961 (0.925–0.983, P=0.013) and 0.897 (0.847–0.934, P=0.022), respectively. The ROC curves of the early and delayed scans were also significantly different (z=4.46, P<0.001). AUC of the ΔSUV max for the early scan was significantly lower compared with delayed scans (z=8.95 vs . 9.13, respectively; P<0.001). Conclusions: Dual-time point 18 F-FDG PET imaging significantly improved the prediction and detection of axillary lymph node metastasis, compared with prediction based on size of lymph node alone, in patients with stage III breast cancer. We found that lymph nodes with continuously increased SUV max values tended to show metastasis, and early SUV max assessment offers the best capacity for prediction of axillary lymph node metastasis.

[学科分类] 外科医学

[关键词] Breast neoplasms;lymph nodes;positron emission tomography (PET);fluorine-18-labeled 2-fluoro-2-deoxy-D-glucose ( 18 F-FDG);maximum standardized uptake value (SUV max )