Triple-Tracer Sentinel Node Mapping: Maximizing Detection, Minimizing Dissection.

Area of Science:

• Oncology
• Surgical Oncology
• Nuclear Medicine

Background:

• Sentinel lymph node (SLN) biopsy is crucial for breast cancer staging.
• Commonly used tracers include technetium-99m (99mTc), indocyanine green (ICG), and methylene blue (MB).
• Limited data exist on the comparative performance of these tracers in routine clinical practice.

Purpose of the Study:

• To audit the performance of 99mTc, ICG, and MB in a triple-tracer approach for SLN biopsy in breast cancer.
• To evaluate sentinel lymph node detection rates, number of nodes retrieved, and tracer concordance.
• To assess subgroup performance, including patients undergoing mastectomy or post-neoadjuvant therapy.

Main Methods:

• A single-center retrospective audit of 111 consecutive SLN procedures.
• Utilized a triple-tracer method combining 99mTc, ICG, and MB.
• Evaluated detection rates, node yield, tracer concordance, and specific patient subgroups.

Main Results:

• Detection rates were 96.4% for 99mTc, 93.7% for ICG, and 78.4% for MB.
• 99mTc and ICG significantly outperformed MB (p < 0.001).
• Triple-tracer workflows improved detection odds (AUCs 0.98 for 99mTc, 0.82 for ICG).

Conclusions:

• Technetium remains a primary tracer for SLN biopsy.
• ICG is a valuable adjunct, enhancing visualization and detection efficacy.
• MB provides redundancy; triple-tracer mapping offers optimal nodal identification and potentially fewer excisions with complete concordance.