5 A Prospective, Double-Blinded, Randomized Controlled Trial Comparing the Intraoperative Injection of Technetium Tc 99m Tilmanocept With Technetium Tc 99m Sulfur Colloid in Breast Cancer Lymphatic Mapping

Anyul Ferez-Pinzon, MD¹; Samuel Corey, MD¹; Haresh Rochani, DrPh, MPH, MBBS²; Elena Rehl, MD³; William Burak, MD¹

¹Memorial Health University Medical Center, Savannah, GA.

²Georgia Southern University, Statesboro, GA.

³Good Samaritan Medical Center, West Palm Beach, FL.

Background

Technetium-labeled sulfur colloid (TSC) is the radiolabeled agent most commonly used for sentinel lymph node (SLN) biopsy. Tilmanocept (Lymphoseek; Navidea), a CD-206 receptor–targeted mapping agent, has also gained popularity due to potential advantages of rapid and tight binding to the SLNs. These attributes may be beneficial when using an intraoperative injection protocol. The performance of these 2 mapping agents was compared in this setting. Study objectives were to assess (1) the difference in the number of SLNs harvested and (2) the difference in time to transcutaneous SLN localization.

Materials and Methods

Patients undergoing breast conservation and SLN biopsy were consented then randomized to receive the same volume of either 0.5 mCi of filtered TSC or 0.5 mCi of tilmanocept injected intradermally after induction of general anesthesia. Axillary transcutaneous γ-detector probe counts were taken at 1-minute intervals until a hot spot was identified. Nodes were excised if their counts per second (cps) were greater than 10% of the cps of the hottest SLN. The number of SLNs was based both on the number of nodes collected intraoperatively and the number recorded in the final pathology report.

Results

The study population consisted of 86 patients, 48 randomized to tilmanocept and 38 to TSC. There were no significant differences in patient or tumor characteristics between the 2 groups. Localization rates were 100% for both cohorts. The mean numbers of SLNs identified and removed were not significantly different (Table). The mean (SD) time to transcutaneous localization was 3.3 (±2.0) minutes for tilmanocept and 3.9 (±2.3) minutes for TSC (P = .19). The average (SD) cps for the hottest node was 2180 (±2461) in the tilmanocept group compared with 2679 (±2687) in the TSC group (P = .94).

TABLE.Number of SLNs Identified

Conclusions

There were no significant differences in the number of SLNs harvested or in the time to transcutaneous localization between tilmanocept and TSC when using an intraoperativeinjection protocol. Either agent can be used without any significant difference in performance.