Meta-analysis of the application value of indocyanine green fluorescence imaging in guiding sentinel lymph node biopsy for breast cancer

The feasibility and added value of indocyanine green tracing in guiding sentinel lymph node biopsy for breast cancer

OBJECTIVE

To compare the effectiveness of combined (indocyanine green [ICG]+ blue dye) tracing versus blue dye alone in guiding sentinel lymph node biopsy (SLNB) in breast cancer.

METHODS

A total of 112 female patients (mean ± SD age: 51.9 ± 11.9 years) with clinically node-negative (cN0) early-stage breast cancer were evaluated based on SLN tracing technique including methylene blue + ICG (n = 17), isosulfan blue + ICG (n = 19) and methylene blue alone (n = 76). Mapping patterns of each SLN, the number of total lymph nodes (TLNs) removed, including metastatic and hyperplastic lymph nodes, and the metastatic lymph node detection rate were analyzed for each tracing technique.

RESULTS

SLN detection rate was 100 % with complementary use of ICG. No significant difference was noted between methylene blue + ICG, isosulfan + ICG and methylene blue alone groups in terms of the mean ± SD number of TLNs removed (3.9 ± 2.5, 4.7 ± 3 and 3.7 ± 2.3, respectively) and metastatic lymph node detection rates (16.0 %, 16.25 % and 13.98 %, respectively). Complementary use of ICG revealed the N0 stage for 66.6 % of cases considered as Nx (cannot be detected) on blue dye alone. Also, 20.0 % of N0 and 11.1 % of N1 cases on blue dye were diagnosed with more advance nodal status (N1 and N2 respectively) after complementary use of ICG.

CONCLUSIONS

The combined tracing (ICG + blue dye) seems valuable not only in terms of the SLN detection rates and lymph node yield but also has an added value in providing more accurate nodal stating and thus a proper final tumor staging with considerable therapeutic implications.

An Updated Review on the Emerging Role of Indocyanine Green (ICG) as a Sentinel Lymph Node Tracer in Breast Cancer

Sentinel lymph node biopsy (SLNB) has become the standard of care for clinically node-negative breast cancer and has recently been shown by clinical trials to be also feasible for clinically node-positive patients treated with primary systemic therapy. The dual technique using both radioisotope (RI) and blue dye (BD) as tracers for the identification of sentinel lymph nodes is considered the gold standard. However, allergic reactions to blue dye as well as logistics issues related to the use of radioactive agents, have led to research on new sentinel lymph node (SLN) tracers and to the development and introduction of novel techniques in the clinical practice. Indocyanine green (ICG) is a water-soluble dye with fluorescent properties in the near-infrared (NIR) spectrum. ICG has been shown to be safe and effective as a tracer during SLNB for breast cancer and accumulating evidence suggests that ICG is superior to BD and at least comparable to RI alone and to RI combined with BD. Thus, ICG was recently proposed as a reliable SLN tracer in some breast cancer clinical practice guidelines. Nevertheless, there is lack of consensus regarding the optimal role of ICG for SLN mapping. Specifically, it is yet to be determined whether ICG should be used in addition to BD and/or RI, or if ICG could potentially replace these long-established traditional SLN tracers. This article is an updated overview of somerecent studies that compared ICG with BD and/or RI regarding their accuracy and effectiveness during SLNB for breast cancer.