Optimization of sentinel lymph node identification techniques in the Indian setting: A randomized clinical trial.

Abstract

The recommended technique of sentinel lymph node biopsy (SLNB) in breast cancer is a combination of blue dye and radiotracer. In the Indian scenario, SLNB is still not routinely practiced due to lack of nuclear medicine facilities and unavailability of isosulfan blue or patent blue violet (PBV). This study was conducted for optimizing SLN identification techniques by comparing the identification rate using PBV and methylene blue (MB) in combination with radiotracer. Single-blinded two-arm parallel design randomized control trial was conducted at an apex teaching and research medical institute in India. Patients with axillary LN-negative breast cancer were included. Blue dye and radio tracer were injected preoperatively, and SLNB was performed using a combination technique. Frozen section was performed. Demographic, clinical, radiological, operative, and histopathological data were recorded. Descriptive statistics were used to represent patient characteristics. Baseline characteristics for entire cohort and between groups were compared using Student's t-test for quantitative variables and Chi-square test for qualitative variables. A total of 119 patients were randomized for mapping with MB and 118 patients with PBV between 2011 and 2015. SLN was identified in 116 patients with MB and 115 with PBV. SLN identification proportions were 97.4% (MB) and 96.6% (PBV). In patients undergoing axillary lymph node dissection, concordance with SLNB was 98.5% and 96.61% in MB and PBV, respectively. False-negative proportion for MB was 2.56% and 7.69% for PBV, respectively. The cost of MB is about INR 15 per ~10-mL vial. The cost of PBV is approximately ~$91 per ampoule (equivalent to approximately INR 8190). SLNB using MB can be recommended as the technique of choice in low-resource settings.