ARE PRE-OPERATIVE LYMPHOSCINTIGRAMS NEEDED FOR LOCALIZATION PRIOR TO SENTINEL NODE BIOPSY?: AN AUDIT TO ENSURE SAFE PRACTICE AND TO PROVIDE ANOTHER VIEW

Abstract

Traditionally lymphoscintigrams are taken after injection of peri-areolar Technetium-99m (Tc-99m) to quantify sentinel nodes before biopsy (SNB). However, recent research suggests that scintigraphy is not an essential adjunct. For service improvement, we stopped using lymphoscintigraphy so as to minimize delay to operating theater and reduce demand on the Nuclear Medicine
Department. We audited early outcomes to ensure quality was maintained. 100 consecutive patients undergoing SNB with lymphoscintigrams were investigated. Lymphoscintigrams were reported by Consultant Radiologists. Reported node count (RNC) was compared to biopsied node count (BNC) using Cohen’s kappa statistic. Lymphoscintigrams were then discontinued, and the results on the next 69 consecutive patients undergoing SNB were analyzed. The BNC was then compared to BNC in patients having lymphoscintigrams. Of the first 100 patients, RNC ranged from 0-5 (mean=1.84, mode=1) and BNC from 1-4 (mean=1.89, mode=1). 90% of lymphoscintigrams were performed on the day of surgery. Cohen’s Kappa statistic was 0.34 (95%CI =0.195 to 0.482, i.e., Fair agreement). RNC was zero in two cases, but SNB was successful. Of 69 patients in the second group with no scan, BNC ranged from 0-4 (mean=1.80, mode=2). There were two cases of failed localization and no significant difference between BNC with or without scans (p=0.16). Sentinel node positivity rate was 36% for those with scans and 25.3% for those without scans, which was not significant (chi-squared, p=0.11). These results correlate to previously published studies. Correlation between RNC and BNC was only in fair agreement, and negative lymphoscintigrams did not result in failed SNB localization. Our study suggests that BNC without scans is safe and effective. Removing the lymphoscintigram will result in measurable cost savings, saving of clinical time (no delay to operating room while waiting for scan or multiple journeys to hospital), freeing the scanner for other scans, and allowing additional time for radiology physicians and staff.