title: A comparative study of 99Tcm-HMPAO and 99Tcm-ECD as a leukocyte labelling agent.
abstract: An attempt was made to use 99Tcm-ethyl cysteinate dimer (99Tcm-ECD) (Neurolite, Du Pont Merck, N. Billerica, MA) to label leukocytes. The radiochemical purity of 99Tcm-ECD, labelling efficiency of leukocytes, cell viability of labelled leukocytes and stability of 99Tcm-ECD-labelled leukocytes were calculated. Compared with the commercial cell-labelling agent, 99Tcm-hexamethylpropyleneamine oxime (99Tcm-HMPAO): (1) the radiochemical purity of 99Tcm-ECD was higher than that of 99Tcm-HMPAO and at immediately, 1, 2, 4, 6, 8 and 24 h after 99Tcm labelling; (2) the labelling efficiency of 99Tcm-ECD-labelled leukocytes was lower than that of 99Tcm-HMPAO; (3) the viability of the labelled white blood cells (WBC) was high for both agents; and (4) the stability of 99Tcm-ECD-labelled leukocytes was worse than that of 99Tcm-HMPAO at 1, 2, 4, 6, 8 and 24 h. It is concluded that although 99Tcm-ECD is more stable than 99Tcm-HMPAO, because of the lower labelling efficiency and power stability of 99Tcm-ECD-labelled leukocytes, 99Tcm-ECD is not a good choice as a leukocyte-labelling agent to replace commercial 99Tcm-HMPAO.
authors.affiliation: Department of Nuclear Medicine, Taichung Veterans General Hospital, Taiwan, Republic of China.
authors.forename: C H
authors.initials: CH
authors.lastname: Kao
authors.forename: W T
authors.initials: WT
authors.lastname: Huang
authors.forename: Y L
authors.initials: YL
authors.lastname: Wang
authors.forename: K S
authors.initials: KS
authors.lastname: Lin
authors.forename: J M
authors.initials: JM
authors.lastname: Lo
authors.forename: S J
authors.initials: SJ
authors.lastname: Wang
mesh_terms: D002470:Cell Survival; D003545:Cysteine / Q000031:analogs & derivatives*; D004355:Drug Stability; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D007962:Leukocytes / Q000166:cytology / Q000378:metabolism; D015609:Organotechnetium Compounds / Q000737:chemistry* / Q000302:isolation & purification; D010091:Oximes / Q000737:chemistry* / Q000302:isolation & purification; D011854:Radiochemistry; D019690:Technetium Tc 99m Exametazime
chemical_list: D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; C059659:technetium Tc 99m bicisate; D003545:Cysteine