Abstract P2-01-35: A one-day protocol with activities lower than 20 MBq for the detection of sentinel lymph nodes - Experience after 150 cases

Abstract

Abstract Introduction: Common protocols for the detection of sentinel lymph nodes (SLN) in early breast cancer often include injection of the tracer one day before surgery. In order to detect enough activity on the day of surgery, the applied activity in many protocols is as high as several hundred MBq. Even in common one-day protocols the activity applied is often up to 50 MBq. We developed a one-day protocol with a mean activity lower than 20 MBq in order to reduce radiation exposure for patients and staff. Here we are presenting our experience after 150 cases. Material and methods: 150 patients with clinically and sonographically negative axilla (cN0) and no multicentricity underwent a SLN biopsy using a low-dose protocol performed on the day of surgery. After ultrasound-guided injection of the tracer (Technetium99) lymphoscintigraphy was performed in all cases. 7 minutes before the first cut 5 ml blue dye was injected in the region of the areola. Fresh-frozen sections of the SLN(s) were not performed. Results: In 149 of 150 patients (99.3%) at least one SLN could be identified by lymphoscintigraphy. The detection rate during surgery with combined tracers Technetium99 and blue dye was 100%. The mean applied activity was 17.8 MBq (9-20). A mean number of 1.3 (0-5) SLNs were identified by lymphoscintigraphy, a mean number of 1.7 (1-5) SLNs were removed during sentinel lymph node biopsy. 36 patients received a secondary axillary dissection according to the historical standard because of involved SLNs. In 11 cases (30.6%) additional involved lymph nodes were found. Conclusion: One-day protocols with an activity lower than 20 MBq are a safe alternative to two-day protocols with significantly higher radiation doses. Using Technetium99 and blue dye in a dual tracer approach, detection rates of 100% are possible in clinical routine with minimal radiation exposure for patients and staff. The number of removed lymph nodes, the rate of secondary axillary dissections and the number of cases with additional involved lymph nodes is not higher than in published trials. Citation Format: Kolberg H-C, Afsah S, Winzer U, Akpolat-Basci L, Stephanou M, Liedtke C. A one-day protocol with activities lower than 20 MBq for the detection of sentinel lymph nodes - Experience after 150 cases [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-35.