Impact of same day vs day before pre-operative lymphoscintigraphy for sentinel lymph node biopsy for early breast cancer (local Australian experience).

Introduction: To assess the impact of delayed vs immediate pre-operative lymphoscintigraphy (LSG) for sentinel lymph node biopsy in a single Australian tertiary breast cancer centre.

Methods: Retrospective cohort study analysing patients with breast cancer or DCIS who underwent lumpectomy or mastectomy with pre-operative LSG and intra-operative sentinel lymph node biopsy from January 2015 to June 2016.

Results: A total of 182 LSG were performed. Group A patients had day before pre-operative LSG mapping (n = 79) and Group B had LSG mapping on the day of surgery (n = 103). The overall LSG localisation rate was 97.3% and no statistical difference was detected between the two groups. The overall sentinel lymph node biopsies (SLN) were identified in 99.6% of patients. The number of nodes excised was slightly higher in Group A (1.90 vs 1.72); however, this was not statistically significant. In addition, the number of nodes on histopathology and the incidence of second echelon nodal detection were also similar between the two groups without statistical significance.

Conclusion: In conclusion, the 2-day LSG protocol had no impact on overall SLNB and LSG detection rates although slightly higher second tier nodes but this did not translate to any difference between the number of harvest nodes between the two groups. The 2-day LSG allows for greater flexibility in theatre planning and more efficient use of theatre time. We recommend a dose of 40 Mbq of Tc99 m pertechnetate-labelled colloid be given day prior to surgery within a 24-hour timeframe.