Lymphoscintigraphy for Sentinel Lymph Node Biopsy in Breast Cancer: Do We Need a Delayed Image?

Background: Sentinel lymph node biopsy has become a standard of care in the treatment of patients with early breast cancer, but clinical guidelines continue to be vague on details of the procedure. We were interested in the results of our 2-day protocol, which includes delayed lymphoscintigraphy at 18 h. Methods: We reviewed the results of preoperative lymphoscintigrams in patients undergoing surgery for breast cancer. Lymphoscintigraphy was performed 2 h after periareolar injection of 4 × 37 MBq 99m Tc nanocolloid (early lymphoscintigraphy) and 18 h following injection (delayed lymphoscintigraphy). The early results were compared with the late results. Results: A total of 238 lymphoscintigraphies were performed in 232 patients (6 bilateral). At 2 h, ≥1 sentinel nodes were visualized in 154/238 (65%) cases; in 84 (35%), no sentinel node was visualized. Delayed lymphoscintigraphy visualized a sentinel node in 40 of 76 (53%) cases with no visualization at 2 h and failed to show a sentinel node in 36 (47%) of these cases (in 8 cases, no delayed lymphoscintigram was obtained). Conclusions: Delayed lymphoscintigraphy was useful in about 50% of the breast cancer patients in whom immediate scintigraphy failed to demonstrate a sentinel lymph node.