Which imaging modality is best for detecting axillary LN metastasis of breast cancer?

A recent study that evaluated eight different imaging modalities for preoperative detection of axillary lymph node (LN) metastasis of breast cancer has found elastography to have the highest surface under the cumulative ranking curve (SUCRA) values. Except for mammography, the other imaging modalities have demonstrated complementary diagnostic roles.

The investigators searched the databases of PubMed, Cochrane, and Embase for studies that assessed the performances of eight different imaging modalities for preoperative axillary LN staging in patients with breast cancer. They then carried out a network meta-analysis in patient-based analyses using direct comparison studies with two or more imaging techniques.

The agreement between direct and indirect treatment effects was examined in order to assess the consistency. Funnel plot asymmetry tests were also conducted to evaluate publication bias. Finally, the investigators obtained the SUCRA values to calculate the probability of each imaging modality being the most effective diagnostic method.

Twenty-two direct comparison studies using different imaging modalities and included a total of 2,197 patients met the eligibility criteria. Elastography demonstrated the highest SUCRA values of sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and diagnostic odds ratio for the preoperative detection of axillary LN metastasis of breast cancer.

High SUCRA values were also observed with fluorine-18 fluorodeoxyglucose positron emission tomography (PET) or PET/computed tomography, fluorine-18 fluorodeoxyglucose PET/magnetic resonance, and contrast-enhanced computed tomography.