Sentinel lymph node accumulation of Lymphoseek and Tc-99m-sulfur colloid using a "2-day" protocol.

Lymphoseek is a receptor-binding radiopharmaceutical specifically designed for sentinel lymph node (SLN) mapping. We conducted a clinical trial which measured the injection site clearance and sentinel lymph node accumulation after a single intradermal injection of Lymphoseek or unfiltered [(99m)Tc]sulfur colloid (TcSC) using a "2-day" protocol for SLN mapping of breast cancer. Eleven patients with breast cancer participated in this study. Five patients received an intradermal administration of 1.0 nmol of (99m)Tc-labeled Lymphoseek; SLN mapping was performed on four subjects within 19 to 27 h. Six subjects received an intradermal administration of TcSC; SLN mapping was performed on five subjects within 18 to 26 h. Lymphoseek exhibited a significantly (P<.001) faster injection site clearance than TcSC. The mean Lymphoseek clearance half-time was 2.18+/-1.09 h compared to 57.4+/-92.8 h for TcSC. The mean sentinel lymph node uptake of Lymphoseek (1.5+/-1.7%) and TcSC (3.5+/-3.1%) was statistically equivalent (P=.213). When an intradermal injection is employed, Lymphoseek demonstrated faster injection site clearance than unfiltered [(99m)Tc]sulfur colloid and persistent SLN accumulation for at least 24 h.

Sentinel lymph node mapping of breast cancer via intradermal administration of Lymphoseek.

Lymphoseek is a molecular imaging agent specifically designed for sentinel lymph node (SLN) mapping. We conducted a Phase I trial which measured the injection site clearance and SLN accumulation after a single intra dermal injection of Lymphoseek or [99mTc]sulfur colloid protocol. Ten patients with breast cancer participated in this study. Five patients received an intradermal administration of 1.0 nmol of 99mTc-labeled Lymphoseek and five patients received an intradermal administration of filtered [99mTc]sulfur colloid (fTcSC). Lymphoseek exhibited a significantly (P<.001) faster injection site clearance than fTcSC. The mean Lymphoseek clearance half-time was 2.61+/-0.72 h compared to 24.1+/-17.7 h for fTcSC. The mean SLN uptake of Lymphoseek (1.1+/-.5%) and fTcSC (2.5+/-4.9%) was statistically equivalent (P=.28). When an intra dermal injection was employed, Lymphoseek demonstrated faster injection site clearance than fTcSC.

Lymphoseek: a molecular imaging agent for melanoma sentinel lymph node mapping.

BACKGROUND: Lymphoseek is a molecular imaging agent specifically designed for sentinel lymph node mapping. We conducted a phase I clinical trial in which Lymphoseek was compared with filtered [(99m)Tc]sulfur colloid (fTcSC) for melanoma sentinel lymph node detection. METHODS: Twenty-four patients (33-81 years) with melanoma participated in this study. Four groups of six patients received an intradermal administration (.5 mCi) of 1.0, 5.0, or 10.0 nmol of (99m)Tc-labeled Lymphoseek or filtered [(99m)Tc]sulfur colloid. The injection site clearance was monitored by nuclear imaging for 3 hours. Lymph nodes obtained by gamma-guided biopsy (4.0-8.7 hours after injection) were assayed for radioactivity. Clinical chemistry values were monitored (before injection, before surgery, and 4 and 24 hours), and whole-body scans were acquired at 1 and 12 hours after injection. RESULTS: Lymphoseek exhibited a significantly (P < .001) faster injection site clearance at all dose levels. The mean Lymphoseek clearance half-time was 2.17 +/- .96 hours (n = 18) compared with 14.7 +/- 6.3 hours for fTcSC (n = 6). The mean sentinel lymph node uptakes of Lymphoseek (.73% +/- .94%) and fTcSC (.85% +/- 1.19%) were statistically equivalent (P = .68). Lymphoseek exhibited a lower mean number of sentinel lymph nodes per basin (1.6) than fTcSC (1.9). No adverse events were observed, nor were any clinically significant alterations in laboratory parameters. Radiation absorbed doses were lower than filtered [(99m)Tc]sulfur colloid. CONCLUSIONS: The molecular imaging agent Lymphoseek demonstrated faster injection site clearance and equivalent primary sentinel node uptake when compared with filtered [(99m)Tc]sulfur colloid.

Dose-dependent biodistribution of [(99m)Tc]DTPA-mannosyl-dextran for breast cancer sentinel lymph node mapping.

[(99m)Tc]DTPA-mannosyl-dextran is a receptor-binding radiopharmaceutical specifically designed for sentinel lymph node mapping. The purpose of this study was to test the biodistribution and safety of [(99m)Tc]DTPA-mannosyl-Dextran at different molar doses. Twenty-four female breast cancer patients participated in this study. Four groups of 6 patients received an injection of 0.2, 1.0, or 5.0 nmol of [(99m)Tc]DTPA-mannosyl-Dextran or filtered [(99m)Tc]sulfur colloid. The injection site clearance was monitored by dynamic imaging for three hours. Whole body scans were acquired at 2.5 and 12, and lymph nodes were assayed for radioactivity after gamma-guided sentinel lymph node biopsy. Injection site clearance of [(99m)Tc]DTPA-mannosyl-Dextran was not statistically different in a dose-dependent manner. Dose-dependent sentinel node uptake was observed (p = 0.03). There were no clinically significant alterations in laboratory parameters among all dose levels at 4 h or 24 h post injection compared to preoperative levels. Radiation absorbed doses did not differ among the three dose levels, but were lower than filtered [(99m)Tc]sulfur colloid.

Lymphoseek: a molecular radiopharmaceutical for sentinel node detection.

BACKGROUND: Lymphoseek is a new radiopharmaceutical that accumulates in lymphatic tissue by binding to a receptor that resides on the surface of macrophage cells. We conducted a phase I clinical trial in which Lymphoseek was compared with filtered [(99m)Tc]sulfur colloid (fTcSC) for sentinel node detection in patients with breast cancer. METHODS: Twelve women (42-71 years) with breast cancer were randomly assigned to a 3-hour imaging protocol with peritumoral/subdermal injections (.5 mCi) of either Lymphoseek (1 nmol; molecular weight, 28 kDa; diameter,.007 micro m) or.2 micro m of fTcSC. Serial images were acquired for 180 minutes. Sentinel nodes, excised within 4.2 to 7.3 hours of administration, were assayed in a dose calibrator. RESULTS: The receptor-binding agent, Lymphoseek, exhibited a significantly (P =.0025) faster injection site clearance (rate,.255 +/-.147/hour; fTcSC rate,.014 +/-.018/hour); the mean Lymphoseek clearance half-time was 2.72 +/- 1.57 hours compared with 49.5 +/- 38.5 hours for fTcSC. The primary sentinel node uptake of Lymphoseek (range,.02%-1.12%; mean,.55% +/-.43%) and fTcSC (range,.00%-1.93%; mean,.65% +/-.63%) did not differ (P =.75). Lymphoseek exhibited a lower mean number of sentinel nodes per study (n = 1.3) than fTcSC (n = 1.7) and a higher concordance with Lymphazurin. CONCLUSIONS: The molecular receptor-binding agent Lymphoseek demonstrated faster injection site clearance and equivalent primary sentinel node uptake when compared with fTcSC.