Intra-individual comparison of sentinel lymph node scintigraphy on the day of injection and on the following day in breast cancer.

Objectives: To compare, intra-individually, the detection rates of sentinel node on lymphoscintigraphy performed on the day of injection (D0) and on the following day (D1) in breast carcinoma. We also compared 2-day and 1-day protocols in the two groups of patients.

Methods: The 2-day and 1-day protocols included 76 patients in group 1 and 23 patients in group 2. Patients from group 1 underwent lymphoscintigraphy twice--at 2 h (lymphoscintigraphy 1) and 18 h (lymphoscintigraphy 2) post-injection at four sites periareolar using 99mTc sulfur colloid. Patients from group 2 underwent lymphoscintigraphy only at 2 h post-injection. The detection rates and the number of sentinel nodes were compared in the two lymphoscintigraphy examinations for group 2.

Results: The detection rate on lymphoscintigraphy in group 1 was 92% at D0 and 96% at D1. The overall agreement between lymphoscintigraphy 1 and lymphoscintigraphy 2 was 69/76 (91%). In 2/76 women, the sentinel node disappeared at D1 on lymphoscintigraphy, but remained detectable during surgery, and in 5/76 women, the sentinel node appeared at D1 on lymphoscintigraphy. The mean number of sentinel nodes detected on lymphoscintigraphy was 2.05+/-0.14 at D0 and 1.76+/-0.11 at D1 (P=0.004) in group 2, the detection rate of the sentinel node was 20/23 (87%).

Conclusion: Our study demonstrated that for patients undergoing the 2-day protocol for sentinel node procedure in early stage breast cancer, the optimal imaging time would be to perform lymphoscintigraphy 1 h after injection, with the possibility of imaging patients the following day in cases where lymphoscintigraphy was negative.