Purpose: To determine the optimal injection path for blue dye and radiocolloid for sentinel lymph node (SLN) biopsy in early breast cancer.
Patients and methods: A prospective randomized multicentric study was initiated to compare the peritumoral (PT) injection site to the periareolar (PA) site in 449 patients.
Results: The detection rate of axillary SLN by lymphoscintigraphy was significantly higher (P = .03) in the PA group (85.2%) than in the PT group (73.2%). Intraoperative detection rate by blue dye and/or gamma probe was similar (99.11%) in both groups. The rate of SLN detection was somewhat higher in the PA group than in the PT group: 95.6% versus 93.8% with blue dye (P = .24) and 98.2% versus 96.0% by probe (P = .16), respectively. The number of SLNs detected by lymphoscintigraphy and by probe was significantly higher in the PA group than in the PT group, 1.5 versus 1.2 (P = .001) and 1.9 versus 1.7 (P = .02). The blue and hot concordance was 95.6% in the PA group and 91.5% in the PT group (P = .08). The mean ex vivo count of the SLN was significantly higher in the PA group than in the PT group (P < .0001).
Conclusion: This study strongly validates the PA injection technique given the high detection rate (99.1%) of SLN and the high concordance (95.6%) between blue dye and the radiotracer, as well as higher significant ex and in vivo counts, improving SLN probe detection.