Intraoperative injection of technetium-99m sulfur colloid is effective in the detection of sentinel lymph nodes in breast cancer

Background Our objective was to determine if intraoperative injection of technetium-99m–labeled sulfur colloid is as effective as preoperative injection in the detection of sentinel lymph nodes (SLNs). Methods Two hundred consecutive patients with breast cancer underwent SLN biopsy examination. Radiocolloid was injected in the preoperative area (group A) or immediately after induction of anesthesia in the operating room (group B). Results The SLN detection rate was similar for groups A (96%) and B (100%; P = .2). Radioactive SLNs were detected in 95% of patients in group A and in 97% of patients in group B (P = .1). The mean number of SLNs harvested was 1.6 and 2.1 for groups A and B, respectively. There was no significant difference in positive SLNs between groups (P = .11). Conclusions Intraoperative injection of sulfur colloid is highly effective in the detection of SLNs, avoiding patient discomfort and surgical schedule delays.