Carbon nanoparticles localized clipped node dissection combined with sentinel lymph node biopsy with indocyanine green and methylene blue after neoadjuvant therapy in node positive breast cancer in China: initial results of a prospective study

Background This study aimed to evaluate the feasibility of applying carbon nanoparticles (CNs) to visualize clip-marked metastatic nodes in combination with indocyanine green (ICG) and methylene blue (MB) as sentinel lymph node (SLN) tracers for targeted axillary dissection (TAD) after neoadjuvant therapy (NAT). Methods This feasibility trial enrolled 40 patients with node-positive breast cancer, and 38 patients completed NAT and surgery were included in the final analysis. Before NAT or surgery, clip-marked nodes were localized with CNs by ultrasonography. After NAT, the clip-marked nodes were removed under the guidance of carbon-tattooing and confirmed by radiography. SLNs were mapped with ICG and MB. Axillary lymph node dissection (ALND) was performed for all patients after TAD. Results The clip-marked nodes were retrieved in all patients. The SLN identification rate was 100%. 29 of 38 clipped-nodes were SLNs. The false-negative rate was 6.25% (2/32,95% CI:1.09% ~ 22.22%) for TAD nodes and 9.38% (3/32,95% CI 3.24%-24.22%) for SLNs, and 18.75% for clipped-nodes (6/32, 95% CI:7.86% ~ 37.04%). No adverse events were reported during clip placement, CNs localization, or the TAD procedure. Conclusions The TAD procedure with CNs to locate and visualize clipped nodes as well as SLN tracing with ICG and MB has good accessibility in China, and this technique could be easily mastered by experienced surgeons. The modified TAD technique has also demonstrated good predictive ability for residual axillary lesions after NAT, and is worth of further evaluation.