Clinical significance of discordances in sentinel lymph node reactivity between radioisotope and indocyanine green fluorescence in patients with cN0 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.

Indocyanine Green Marking of Axillary Sentinel Lymph Nodes in Early Breast Cancer

Axillary sentinel lymph node excision (SLNE) in breast cancer patients with clinically node-negative disease may be carried out using different tracers. The standard tracer is technetium colloid (99mTc). Indocyanine green (ICG) can be used as an alternative. This study aimed to evaluate the clinical usefulness of this fluorescent dye in a standardized setting.

A prospective, single-center cohort study carried out at the University Gynecological Hospital of Rostock from September 2023 to May 2024 carried out sentinel lymph node marking using only ICG in patients with breast malignancies. The ICG injection was administered immediately after the induction of anesthesia. Detection of the sentinel lymph node (SLN) was done using a laparoscopy system suitable for ICG. The aim was to determine the detection rate (DR) for SLNs marked exclusively using ICG and to record any complications. The costs of using ICG to mark SLNs were compared with those for 99mTc marking.

During the study period, contraindications against marking with ICG were ascertained for five (3.8%) of 132 patients with planned SLNE. A total of 100 SLNEs were carried out after ICG marking in patients who met the inclusion criteria in the context of the study. A median of two SLNs were resected. The detection rate (DR) for SLNs was 98.0%. SLNs were identified in all obese patients. No serious systemic side effects occurred following ICG injection. Transient skin discoloration in the area around the injection site were observed in eight patients. The direct cost of ICG marking was 62.73 Euros, which was 170.36 Euros lower than the cost of 99mTc marking.

The detection rate of axillary SLNs marked using ICG is high and the method is cost-effective, has few side effects and can also be used in obese patients. Contraindications against the administration of ICG are rare. Marking with ICG is a good alternative to the 99mTc method and offers advantages in terms of costs, logistics, no exposure to radiation, and patient comfort.

Comparison of Indocyanine Green with conventional tracers for sentinel lymph node biopsy in breast cancer: A multidisciplinary evaluation of clinical effectiveness, safety, organizational and economic impact

BACKGROUND

Breast cancer is a global health problem, and sentinel lymph node biopsy (SLNB) is the standard procedure for early-stage breast cancer. Technetium-99 (TC-99), alone or combined with blue dye (BD) are conventional tracers for SLNB, but they have safety, availability, and cost limitations. Indocyanine green (ICG) is an alternative tracer that has been gaining acceptance among healthcare professionals. This study aimed at assessing the clinical and economic value of ICG in hospital settings, using the health technology assessment (HTA) framework.

METHODS

We conducted a comprehensive evaluation of ICG for SLNB, based on literature sources and data collected from two Italian hospitals that switched from TC-99 to ICG. We analyzed ICG's technical attributes through technology documentation and relevant databases. We performed a systematic literature review of 36 studies to assess the clinical effectiveness and safety of ICG. We obtained organizational insights from clinicians and the clinical engineer involved in the study. We applied Time-Driven Activity-Based Costing (TDABC) and Budget Impact Analysis (BIA) to estimate the economic impact of ICG. The ethical, legal, and social implications of ICG were considered through clinicians' inputs and technology documentation.

RESULTS

Our results showed that ICG had equivalent or superior clinical effectiveness compared to TC-99 and BD, with minimal adverse events. ICG simplified the surgical pathways, by streamlining procedures, reducing waiting times, and increasing flexibility in scheduling surgeries. Moreover, the TDABC analysis showed significant cost reductions by avoiding the need for pre-operative lymphoscintigraphy and hospitalization, with average savings per single care pathway of around 18% for ICG compared to TC-99. Finally, ICG improved patient experience, and proved regulatory compliance.

CONCLUSIONS

This study provided strong evidence for ICG's clinical and economic value for SLNB in breast cancer. It ascertained ICG as a valuable alternative to conventional tracers, ensuring clinical effectiveness along with economic and organizational benefits.

Fluorescent-guided surgery and the use of indocyanine green sentinel lymph node mapping in the pediatric and young adult oncology population

BACKGROUND

Technetium-99 (99m Tc) lymphoscintigraphy with blue dye injection is an accepted method for sentinel lymph node (SLN) mapping, but blue dye has known adverse effects, and injection of 99m Tc may increase time under anesthesia for pediatric patients. Indocyanine green (ICG) may serve as an adjunct to assist with visibility and identification of SLNs. We hypothesized that sensitivity of ICG was similar to blue dye in SLN biopsies.

METHODS

Thirty patients (36 procedures with 96 total specimens) underwent preoperative intradermal injection of 99m Tc, followed by intradermal injection of isosulfan blue and ICG. Test characteristics of blue dye, ICG, and 99m Tc included sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

ICG had a sensitivity of 87% and PPV of 83% for detection of 99m Tc-hot lymph nodes; blue dye had a sensitivity of 44% and PPV of 97%. For detection of pathologically confirmed lymph nodes, ICG had a sensitivity of 84% and a positive predictive value (PPV) of 91%. 99m Tc had a sensitivity of 82% and a PPV of 94%. ICG had no significant difference in odds of being positive in pathology-confirmed lymph nodes compared to 99m Tc (odds ratio [OR], 0.818; 95% confidence interval [CI], 0.3-2.172; p = .823) and had higher odds than isosulfan blue (OR, 0.025, 95% CI, 0.001-0.148; p < .001).

CONCLUSION

This study established the efficacy of ICG as an adjunct to SLNB in the pediatric and young adult population. ICG was safe, more efficacious than blue dye, and may obviate the need for lymphoscintigraphy in selected patients resulting in reduced time under anesthesia.

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.