Imaging methods for the local lymphatic system of the axilla in early breast cancer in patients qualified for sentinel lymph node biopsy

Diagnostic Performance of Indocyanine Green Plus Methylene Blue Versus Radioisotope Plus Methylene Blue Dye Method for Sentinel Lymph Node Biopsy in Node-Negative Early Breast Cancer

PURPOSE

Sentinel lymph node biopsy (SLNB) by dual-dye method (radioisotope plus blue) is the gold standard for axillary staging in patients with breast cancer, but in developing countries, logistic issues and financial constraint play a vital role. Recently, indocyanine green (ICG) has emerged as an alternative to radioisotope (technetium-99 [Tc-99]) for SLNB in breast cancer. This study compared the diagnostic performance of Tc-99 plus methylene blue (MB) dye versus ICG + MB dye SLNB.

METHODS

Two hundred seven patients with early breast cancer (T1-3N0) were included in the study from 2017 to 2019. SLNB was done either with Tc-99 + MB or with ICG + MB as per availability of radioisotope. SLN identification rate (IR), SLN positivity rate, and metastatic SLN counts were compared between the 2 groups.

RESULTS

IR was 199 (96%) of 207. IR was 95% in Tc-99 + MB compared with 97% with ICG + MB. The mean number of SLNs identified were 3.17 (standard deviation [SD], 1.84), with > 1 SLN identified in 87% patients by Tc-99 + MB. SLN was positive in 31.3% of patients with a metastatic SLN count of 0.37 (SD, 0.76). With ICG + MB, the number of SLNs was 2.73 (SD, 1.55), with > 1 SLN identified in 79% of patients. Twenty-eight percent of patients had positive SLNs, with a metastatic SLN count of 0.41 (SD, 0.77). A sharp decline in the availability of Tc-99 was observed, with 58% of patients in 2014 and only 12% of patients in 2018.

CONCLUSION

ICG is equivalent to Tc-99 for SLNB in early breast cancer and has a good potential to be adopted by surgeons in resource-constrained setups.

First experience with a new technique: Portable gamma camera usage for sentinel lymph node identification in a patient with breast cancer

The newest development in sentinel lymph node imaging is portable gamma probe imaging. In this case report, results of all SLN detection methods were analyzed. The patient was imaged using a large field-of-view gamma camera with additional blue dye administration and intraoperative localization of sentinel lymph node using both gamma probe and portable gamma camera was performed. In this case report, the value of additional portable gamma camera imaging was analyzed.

Retrospective observational study about reducing the false negative rate of the sentinel lymph node biopsy: Never underestimate the effect of subjective factors

Reducing the false negative rate of sentinel lymph node biopsy (SLNB) for breast cancer patients has always been a focus of clinical research. We aimed to map the sentinel lymph nodes (SLNs) in detail, and analyze the factors related to SLNs located at locations that are often ignored by surgeons, to reduce the rate of false negatives from SLNB. A retrospective analysis involving 545 breast cancer patients who underwent SLNB in west China hospital between August 2010 and February 2016 was performed. Blue dye, radioisotope, or combined methods were used for tracing SLNs. Using blue dye, radioisotope, and a combination of blue dye and radioisotope successfully traced SLNs in 479, 507, and 525 patients, the detection rate was 88.2%, 93.9%, and 97.4%, respectively. Among the 1559 detected SLNs, 139 (9.6%) were located at the latissimus dorsi lateral margin, and 108 (6.9%) were located at level 2. Subcutaneous injection of radioisotope (P = .004) and intradermal injection of blue dye (P = .002) were independent factors associated with SLNs distributed at level 2 and the latissimus dorsi lateral margin, respectively. It was noteworthy that 2 of 7 patients had skipping metastasis in level 2, so subcutaneous injection of the isotope is strongly recommended for tracing SLNs distributed in level 2 because of the possibility of skipping metastasis. Though intradermal injection of blue dye was superior methods for tracing SLNs located at the latissimus dorsi lateral margin, we surprisingly found those patients with metastasis to the latissimus dorsi lateral margin nodes also could have metastasis to level 1 (expect for the latissimus dorsi lateral margin) nodes, it seemed that maybe there is no need to excise SLNs at the latissimus dorsi lateral margin in SLNB, whether such nodes should be regarded as useful for SLNB still needs to be determined by further large, multicenter clinical studies.