PLATELET LABELING WITH GA-67 MPO - A COMPARISON WITH IN-111-MPO

Ga-68-labeled platelets could be useful for positron emission tomograp hy (PET) studies. The labeling behaviour of human platelets labeled wi th Ga-67-MPO and the viability of Ga-67-MPO platelets were studied and compared, respectively, with In-111-MPO. The platelet labeling yield of Ga-67-MPO increased with platelet concentration and with temperatur e and time of incubation [reaching a maximum (<20%) at 1 x 10(9) plate lets/mL, 37 degrees C, 30 min]. In-111-MPO shows a similar behaviour, but labeling yield of platelets is significantly higher as compared to Ga-67-MPO. Viability of Ga-67-MPO- and In-111-MPO-labeled platelets i s maintained. The data suggest that Ga-68-MPO is not a promising PET r adiopharmaceutical for potential studies with radiolabeled platelets i n clinical practice.