Background: The purpose of the present study was to evaluate whether the combination of dye and radioisotope would improve the detection rate of sentinel nodes (SN) and the diagnostic accuracy of axillary lymph node status over dye alone in patients with breast cancer.
Methods: Sentinel node biopsy (SNB) was performed in stages I or II breast cancer patients with clinically negative nodes using dye alone (indocyanine green) or a combination of dye and radioisotope (99mTc-radiolabelled tin colloid).
Results: SNB guided by dye alone was performed in 93 patients and SNB guided by a combination of dye and radioisotope was performed in 138 patients. The detection rate of SN was significantly (P = 0.006) higher in the combination group (94.9%) than in the dye alone group (83.9%). The sensitivity, specificity, and overall accuracy of SNB in the diagnosis of axillary lymph node status were 100, 100, and 100%, respectively, for the combination group, and 81.0, 100, and 94.9%, respectively, for the dye alone group. There were no false negatives in the combination group, but four false negatives (19.0%) in the dye alone group. The combination method was significantly superior to the dye alone method for sensitivity (P = 0.011) and accuracy (P = 0.018).
Conclusions: The addition of a radioisotope to the dye in SNB increases the detection rate of SNs in breast cancer patients, and SNs detected by the combination method predict the axillary lymph node status with greater accuracy than those detected by the dye alone method.