This study included 126 breast cancer patients who underwent SLNB with ICG and MB from October 2017 to December 2019 in our department. The study was in accordance with Helsinki Declaration and approved by the Institutional Review Board of Zhengzhou People's Hospital. The IRB numbers was 2017CTN0118, and all patients signed informed consent.
The patient inclusion criteria consisted of pathological diagnosis of breast cancer; maximum tumor diameter of 5 cm; no identification of clinically metastatic axillary lymph nodes through ultrasound, chest computed tomography or breast magnetic resonance imaging. And the exclusion criteria included palpable axillary lymph nodes; previous axillary surgery; neoadjuvant chemotherapy or endocrine therapy.
SLNs identification using ICG:
One minute before surgery, 1 ml of ICG solution (Yichuang Pharmaceutical LLC, Dandong, China.) injected subcutaneously and intradermally at the areola. Following gentle breast massage, ICG fluorescence was stimulated and detected by a hand-held photodynamic eye camera (MingDe Biomedical Technology Corporation, Hebei, China). Later, an incision was made to start the SLNB where the fluorescence disappeared. After excising the fluorescent nodes, the area of a 3 cm diameter around the first TLNs was gently palpated, and any enlarged or hard palpable suspicious LNs were also excised. PLNs were more offwhite in color and more pliable and tough in texture than fat or glandular tissue. When suspicious nodes were identified, they were excised and handled as if they were lymph nodes.
SLNs identification using MB:
Ten minutes before surgery, 1 ml of 1% MB (Jichuan Pharmaceutical, Taizhou, China) was subdermally injected into the periareolar region of 4 quadrants of the breast (clockwise). Following gentle massage, a small transverse incision was made one centimeter below the axillary line to detect blue-stained nodes. After that, palpable suspicious nodes around the blue-stained nodes were also excised.
After the complication of SLNB procedure, we divided all removed lymph nodes into two parts: traced lymph nodes (TLNs) and palpated lymph nodes (PLNs). TLNs were defined as any fluorescent lymph nodes located by photodynamic eye camera or any node stained by MB. PLNs were any lymph nodes that were clinically suspicious on systematic palpation of the area of a 3 cm diameter around the first TLNs. All these SLNs were examined by intraoperative histopathology examination of sliced 2-mm sections of frozen tissues to detect SLN metastasis. In patients displaying malignant cells in the nodesof frozen sections, ALND was performed as a standard axillary treatment.
Chi-squared test were used to compare detection rate of SLNs, number of
SLNs and detection rate of metastatic nodes between the results with palpation and those without palpation. All statistical analyses were performed using IBM SPSS statistics version 23 (SPSS Inc., Chicago, IL, USA) software, and p-value of < 0.05 represented statistical significance.