99mTc-Tilmanocept: A Novel Molecular Agent for Lymphatic Mapping and Sentinel Lymph Node Localization

Abstract

AlabamaCE credit: For CE credit, you can access the test for this article, as well as additional JNMT CE tests, online at https://www.snmmilearningcenter.org. Complete the test online no later than June 2018. Your online test will be scored immediately. You may make 3 attempts to pass the test and must answer 80% of the questions correctly to receive 1.0 CEH (Continuing Education Hour) credit. SNMMI members will have their CEH credit added to their VOICE transcript automatically; nonmembers will be able to print out a CE certificate upon successfully completing the test. The online test is free to SNMMI members; nonmembers must pay $15.00 by credit card when logging onto the website to take the test.Preoperative lymphatic mapping in conjunction with intraoperative γ-probe detection is widely used for sentinel node localization in melanoma, breast cancer, and other malignancies. 99m Tc-radiocolloids have been the standard radiotracers used for sentinel node mapping. 99m Tc-tilmanocept is a receptorbinding molecular imaging agent approved by the U.S. Food and Drug Administration for lymphatic mapping and lymph node localization in breast cancer, melanoma, clinically nodenegative squamous cell carcinoma of the oral cavity, and other solid tumors. It has several advantages over conventional radiocolloids, including rapid injection site clearance, high sentinel node extraction, and low distal node accumulation, which can lead to efficient resource use.

New technologies in radioguided surgery in complex anatomic areas

“…The estimated effective dose is low, ranging from 0.20 to 0.33 mSv [68]. The radiopharmaceutical was designed to overcome limitations in cancers with complex lymphatic drainage [68]. In phase I-III trials, various advantages were reported for SLN localization: (a) fast drainage from the injection site due to the small particle size (7 nm) compared with 99m Tc-nanocolloids (50-80 nm) and 99m Tcsulfur colloids (100-220 nm), (b) specific binding over at least 24 h, (c) limited drainage to secondary nodes, and Intraoperative 3D visualization using fhSPECT (d-f) enabled the detection of the SLNs.…”

“…99m Tc-nanocolloids are the most commonly used tracers in Europe, whereas in the USA mainly filtered 99m Tc-sulfur colloids are applied [2]. In 2013, a new receptor-targeted radiopharmaceutical ( 99m Tctilmancept) was approved by the US Food and Drug Administration (FDA) for lymphatic mapping and SLN localization in breast cancer, melanoma, oral squamous cell carcinoma, and other solid tumors [68]. The European Medicines Agency (EMA) also authorized the use of 99m Tc-tilmancept in 2014 [69].…”

“…99m Tc-tilmancept binds specifically to the mannose receptor 206 on the surface of macrophages and dendritic cells that are present in LNs [70]. Administration is similar to that of the radiopharmaceuticals commonly used for SLNB [68]. The manufacturer recommends administration at least 15 min and at maximum 15 h prior to the surgical procedure [33].…”

“…The manufacturer recommends administration at least 15 min and at maximum 15 h prior to the surgical procedure [33]. The estimated effective dose is low, ranging from 0.20 to 0.33 mSv [68]. The radiopharmaceutical was designed to overcome limitations in cancers with complex lymphatic drainage [68].…”

“…The SLN at level I contained a metastasis (pN1). Adapted from [62]; permission number: 3804921324247 (d) high extraction in the SLN due to selective binding to CD206 receptors [68,71,72]. Due to the high tracer accumulation in the real SLN, an excellent detection rate (97.6 %), sensitivity (97.4 %), and negative predictive value (97.8 %) were demonstrated in a multicenter phase III trial investigating 85 patients with HN cancers [73].…”