A rapid method for the preparation of 99Tcm hexametazime-labelled leucocytes

99Tcm(±)-hexamethylpropyleneamineoxime (HMPAO) (99Tcm Hexametazime) has been recently reported as an alternative for labelling leucocytes. This technique has been modified to give a simpler routine in-house labelling technique. It has three advantages: only about 20 ml of blood is required, the labelling time is just under 1 h and high yields of labelled leucocytes are obtained (mean of 500 MBq per injection dose). The properties of labelled leucocytes using this modified method are; 80% granulocyte-bound radioactivity, a rapid lung transit and a blood granulocyte recovery of 40% at 30 min similar to those described previously. The viability of the labelled leucocytes was tested and confirmed in vitro using a migration technique and in vivo by showing no lung retention on early imaging and high splenic uptake. A rapid in-process chromatography assessment procedure for regulating the protocol has been developed. Successful abscess imaging by 4 h has been achieved in 21 patients with normal results in another 22 patients without abscesses. This simpler method should encourage a more widespread application of scintigraphy using radiolabelled granulocytes. (author)