# Comparative Evaluation of Sentinel Lymph Node Detection Rates in Breast Cancer Surgery: “ICG + Patent Blue” Versus “99mTc + Patent Blue”, a 11-Year Single-Center Study

## TL;DR

This study compares two methods for detecting sentinel lymph nodes in breast cancer surgery and finds both are equally effective, but one avoids radiation.

## Contribution

The study provides a long-term comparative evaluation of ICG + PB versus 99mTc + PB for SLN detection in breast cancer surgery.

## Key findings

- Both ICG + PB and 99mTc + PB had similarly high sentinel lymph node detection rates.
- Increasing age was linked to patent blue failure, and upper-inner quadrant tumors were linked to 99mTc failure.
- Indocyanine green showed no identifiable predictors of failure and is a radiation-free alternative.

## Abstract

Breast cancer is the most common cancer affecting women worldwide. To determine whether cancer has spread, surgeons often perform a sentinel lymph node (SLN) biopsy, which identifies the first lymph node(s) likely to contain cancer cells while avoiding more extensive lymph node removal. This study compared two dual-tracer techniques used to detect these lymph nodes: indocyanine green combined with patent blue dye (ICG + PB) and technetium-99m combined with patent blue dye (99mTc + PB). We found that both methods had similarly high detection rates. Increasing age was associated with the failure of patent blue detection, and tumors located in the upper-inner quadrant were linked to technetium-99m detection failure. No factors were associated with failure when using indocyanine green. These findings suggest that indocyanine green is a reliable, radiation-free alternative for SLN mapping in breast cancer surgery.

Background: Breast cancer is the most common malignancy in women, and sentinel lymph node (SLN) biopsy is essential for accurate nodal staging while avoiding unnecessary axillary dissection. Aim: This study aimed to compare SLN detection rates between two dual-tracer techniques: indocyanine green plus patent blue (ICG + PB) and technetium-99m plus patent blue (99mTc + PB), and to identify factors associated with detection failure for each tracer. Methods: All clinically node-negative breast cancer patients undergoing SLN biopsy between January 2014 and December 2024 were retrospectively evaluated. SLN detection was considered successful when at least one node was identified intraoperatively and confirmed histologically. Multivariate analysis assessed clinical and tumor-related predictors of failure. Results: A total of 269 procedures (258 patients) were analyzed, including 152 ICG + PB and 117 99mTc + PB procedures. Detection rates were comparable between groups (95.4% vs. 94.9%, p = 0.96), with no significant differences in the number of SLNs retrieved or nodal positivity. Multivariate analysis identified increasing patient age as the only independent predictor of PB failure, while no variables were associated with ICG failure. Tumor location in the upper-inner quadrant was the sole predictor of 99mTc failure. Conclusions: ICG + PB and 99mTc + PB provide equivalent and high SLN detection rates. ICG appears to be a robust, radiation-free alternative with no identifiable predictors of failure, supporting its role as an effective mapping strategy, particularly in centers aiming to optimize workflow and patient safety, despite the limited available data on its efficacy.