Use of ^99mTc-Tilmanocept as a Single Agent for Sentinel Lymph Node Identification in Breast Cancer: A Retrospective Pilot Study

Abstract

Tc-tilmanocept received recent Food and Drug Administration approval for lymphatic mapping in 2013. However, to our knowledge, no prior studies have evaluated the use of Tc-tilmanocept as a single agent in sentinel lymph node (SLN) biopsy in breast cancer. We executed this retrospective pilot study to assess the ability of Tc-tilmanocept to identify sentinel nodes as a single agent in clinically node-negative breast cancer patients. Patients received a single intradermal injection overlying the tumor of either 18.5 MBq (0.5 mCi) ofTc-tilmanocept on the day of surgery or 74.0 MBq (2.0 mCi) on the day before surgery by a radiologist. Immediate 3-view lymphoscintigraphy was performed. Intraoperatively, SLNs were identified with a portable γ-probe. A node was classified as hot if the count (per second) of the node was more than 3 times the background count. Descriptive statistics are reported. Nineteen patients underwent SLN biopsy with single-agentTc-tilmanocept. Immediate lymphoscintigraphy identified at least 1 sentinel node in 13 of 17 patients (76.5%). Intraoperatively, at least 1 (mean, 1.7 ± 0.8; range, 1-3) hot node was identified in all patients. Three patients (15.8%) had 1 disease-positive SLN. In this small, retrospective pilot study,Tc-tilmanocept performed well as a single agent for intraoperative sentinel node identification in breast cancer. A larger, randomized clinical trial is warranted to compare Tc-tilmanocept as a single agent with other radiopharmaceuticals for sentinel node identification in breast cancer.

Tuberculosis: Role of Nuclear Medicine and Molecular Imaging With Potential Impact of Neutrophil-Specific Tracers

“…[ 99m Tc]Tc-tilmanocept, which is a molecular marker for the mannose receptor CD206, has been utilised in lymphoscintigraphy in oncology (72,73) and also limited phase 1 studies in mapping atherosclerotic inflammation (74) and rheumatoid arthritis (75,76). Enhanced expression of CD206 in macrophages, particularly in lung and pleural tissue with caseating granuloma, has portended a poorer prognosis in patients with these lesions (77).…”

Comparative Study of a Series of 99mTc(CO)3 Mannosylated Dextran Derivatives for Sentinel Lymph Node Detection

“…An alternative direction for developing radiopharmaceuticals for SLND targets the mannose receptors on the surface of the macrophage cells present in the lymph node [ 10 , 11 , 12 , 13 , 14 ]. A series of mannosylated dextrans have been explored in that direction, taking advantage of the nanoparticle nature of dextrans and their suitability for biological applications, properties such as being water soluble, biodegradable, non-toxic, and available in various molecular weights [ 15 , 16 , 17 , 18 , 19 , 20 ]. This direction resulted in the development of 99m Tc-tilmanocept, the first authorized radiopharmaceutical in Europe and USA to selectively localize the SLN by binding to the mannose receptor (CD206).…”