Performance of Tc ^99m tilmanocept when used alone is as or more effective in localizing sentinel nodes than sulfur colloid plus blue dye.

Objectives The objective of the analysis was to statistically compare the rates of localization of Tc 99m tilmanocept (TcT) when used alone [a FDA and EMA-approved CD206 receptor-targeted sentinel lymph node biopsy (SLNB) radiotracer] with the non-targeted agents sulfur colloid (SC) alone, blue dye (BD) alone, and their combination (SC+BD), in breast cancer patients.

Methods Tc 99m tilmanocept was studied in two prospective phase III clinical trials of SLNB in clinically node-negative breast cancer patients, in which TcT was compared within-patient to BD (published: Wallace ASO 2013). Localization data for SC alone, BD alone, and SC with BD, from a systematic literature review for clinical research with these agents in the United States, was presented at the SNM 2012 Annual Meeting. This analysis compared the TcT-only findings from those trials with the localization data previously presented for SC, BD, and their combined use. The counts of patients studied and localized patients were provided and per patient localization rates were computed. The differences between the rates for the treatment groups (TcT vs SC, TcT vs BD, and TcT vs SC+BD) were calculated with asymptotic 95% confidence intervals (95% CI). Non-inferiority and superiority testing were conducted.

Results

The 95% CIs for the differences between TcT and SC alone, BD alone, and the SC+BD combination lie completely above zero, indicating that the TcT localization rate is significantly larger than the comparison localization rates. Therefore, TcT showed superiority to the two tracers and their combined use in the studied breast cancer patients.

Conclusions Based upon statistical comparison of Tc 99m tilmanocept performance in two phase III clinical trials and presented data on the individual and combination use of Tc 99m sulfur colloid and blue dye, Tc 99m tilmanocept per patient localization is superior to the localization found with SC alone, BD alone, and the combination of the non-targeted tracers in breast cancer patients.