Complement of peritumoral and subareolar injection in breast cancer sentinel lymph node biopsy

Abstract

The optimal site for injection of mapping tracers is controversial in sentinel lymph node (SLN) biopsy for breast cancer. We evaluated whether a combination of peritumoral (PT) injection and subareolar (SA) injection can improve the identification rate of SLN biopsy and decrease the false-negative rate. Two hundred one patients underwent SLN biopsy with PT injection of radioisotope and SA injection of blue dye. The overall identification rate for blue and/or hot lymph nodes was 99.5%; the identification rate of blue-dyed lymph nodes was 98.0% and that of hot lymph nodes was 97.0%. However, no concordance between the hot node and the blue node was found in 17 patients (8.5%). Among SLN-positive 51 patients, 4 patients had blue-only positive SLN and 7 had hot-only positive SLN. Consequently, the false-negative rates were at least 7.8% for PT injection and 13.7% for SA injection, while axillary lymph node dissection was not performed in SLN-negative patients. However, a combination of both injections significantly decreased the false-negative rate. The success of SLN mapping is optimized not only by using dye and isotope in combination but also by using PT and SA injections in combination.