technetium (99mtc) tilmanocept technetium (99mtc) tilmanocept technetium (99mtc) tilmanocept, trade name lymphoseek, is a radiopharmaceutical diagnostic imaging agent used to locate lymph nodes which may be draining from tumors, and assist doctors in locating lymph nodes for removal during surgery. technetium (99mtc) tilmanoceptclinical datatrade nameslymphoseekahfs/drugs.commicromedex detailed consumer informationlicense data us dailymed: tilmanocept pregnancycategory au: c routes ofadministrationintradermal, subcutaneous, intratumoratc codev09ia09 (who) legal statuslegal status au: s4 (prescription only)& uk: pom (prescription only) us: ℞-only eu: rx-only pharmacokinetic dataelimination half-life1.75 to 3.05 hours at injection siteidentifiers iupac name dextran 3-propyl 17-carboxy-10,13,16-tris(carboxymethyl)-8-oxo-4-thia-7,10,13,16-tetraazaheptadec-1-yl 3-amino]ethyl]thio]propyl ether technetium-99m complexes cas number1262984-82-6 yunii8ihi69pqtckeggd11543chemical and physical dataformula(c6h10o5)n(c19h28n4o9s99mtc)3–8(c13h24n2o5s2)12–20(c5h11ns)0–17molar mass15,281–23,454 g/mol the most common side effects identified in clinical trials was pain or irritation at the injection site. it was approved by the u.s. food and drug administration (fda) in march 2013, for the imaging of lymph nodes.