A comparative study of dual-layer spectral CT and 18F-FDG-PET/CT multi-quantitative parameters in the diagnosis of sentinel lymph nodes in breast cancer.

Abstract

Objective: To compare the diagnostic efficacy of dual-layer spectral computed tomography (DSCT) and 18-F fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in preoperative identification of metastatic sentinel lymph nodes (SLNs) in patients with breast cancer.

Methods: This retrospective study analyzed 97 patients who underwent DSCT and 107 patients who underwent 18F-FDG-PET/CT, classified by pathology into SLN-positive group and SLN-negative group. Quantitative measurements included: (1) DSCT parameters (normalized iodine concentration[nIC], effective atomic number [Zeff], the slope of the spectral Hounsfield unit curve [λHU] in both arterial and venous phases) and (2) the maximum standardized uptake value (SUVmax) of 18F-FDG PET/CT. Statistical analysis involved group comparisons, logistic regression for independent predictors, and receiver-operating characteristic (ROC) curve analysis (area under the curve [AUC], sensitivity, and specificity).

Results: The results showed that SUVmax and spectral parameters, including Zeff in the venous phase, nIC in both arterial and venous phases, and λHU in both arterial and venous phases, were significantly higher in metastatic SLNs compared to non-metastatic SLNs. Logistic regression analysis identified both λHU in the venous phase and SUVmax as independent risk factors for predicting metastatic SLNs. ROC curve analysis indicated that SUVmax had a higher diagnostic efficiency (AUC: 0.905) than the combined spectral parameters (AUC: 0.834). Specifically, SUVmax demonstrated higher specificity (97 vs. 53%) but lower sensitivity (77 vs. 98%) than the spectral parameters.

Conclusions: Compared with DSCT, 18F-FDG-PET/CT demonstrated higher specificity in identifying metastatic SLNs in breast cancer patients, but was less sensitive than spectral parameters. Spectral parameters can serve as a noninvasive tool for preoperative identification of metastatic SLNs in breast cancer.