A second radioisotope injection enhances intraoperative sentinel node identification in breast cancer patients without visualized nodes on preoperative lymphoscintigraphy.

PURPOSE: To evaluate the influence of a second radioisotope injection on the intraoperative success rate in patients with non-visualized axillary sentinel nodes (SN).
MATERIAL AND METHODS: Altogether, 534 consecutive breast cancer patients with lymphoscintigraphy (LS) and SN biopsy and were included. An intratumoral injection of 99mTc-labeled human albumin colloid with a median dose of 93 MBq was applied. Forty-two of the 80 patients without axillary hot spots on LS received a second tracer injection with a median dose of 70 MBq.
RESULTS: The visualization rate of axillary SN was 454/534 (85%). The intraoperative SN identification rate was 97% in patients with and 69% in patients without visualized SN in the axilla (P<0.00005), but the success rate was higher (88%) with a second radioisotope injection than without it (47%; P<0.0002).
CONCLUSION: The failure rate in intraoperative SN identification was minimized using a second radioisotope injection in patients without axillary SN on LS.