Objective: To compare the (sentinel) lymph node detection rate of ICG-fluorescent imaging versus standard-of-care 99mTc-nanocoilloid for sentinel lymph node (SLN)-mapping.
Summary background data: The current gold-standard for axillary staging in patients with breast cancer is sentinel lymph node biopsy (SLNB) using radio-guided surgery with radioisotope technetium (99mTc), sometimes combined with blue dye. A promising alternative is fluorescent imaging using indocyanine green (ICG).
Methods: In this non-inferiority trial, we enrolled 102 consecutive patients with invasive early-stage, clinically node-negative breast cancer. Patients were planned for breast conserving surgery and SLNB between August 2020 and June 2021. The day or morning before surgery, patients were injected with 99mTc-nanocolloid. In each patient, SLNB was first performed using ICG-fluorescent imaging, after which excised lymph nodes were tested with the gamma-probe for 99mTc-uptake ex-vivo, and the axilla was checked for residual 99mTc-activity. Detection rate was defined as the proportion of patients in whom at least one (S)LN was detected with either tracer.
Results: In total, 103 SLNBs were analysed. The detection rate of ICG-fluorescence was 96.1% (95%CI=90.4-98.9%) versus 86.4% (95%CI=78.3-92.4%) for 99mTc-nanocoilloid. The detection rate for pathological lymph nodes was 86.7% (95%CI=59.5-98.3%) for both ICG and 99mTc-nanocoilloid. A median of 2 lymph nodes were removed. ICG-fluorescent imaging did not increase detection time. No adverse events were observed.
Conclusion: ICG-fluorescence showed a higher (S)LN detection rate than 99mTc-nanocoilloid, and equal detection rate for pathological (S)LNs. ICG-fluorescence may be used as a safe and effective alternative to 99mTc-nanocoilloid for SLNB in patients with early-stage breast cancer.