Labelling of EDTMP (Multibone) with [111In], [99mTc] and [188Re] using different carriers for "cross complexation"

Detection and follow up of bone metastases are important in diagnostic nuclear medicine. However, although the methods are well established, the mechanisms involved in the bone uptake of radiotracers still remain speculative. The aim of the present study was the evaluation and comparison of the labelling of EDTMP with different radionuclides (n.c.a. = no carrier added) and different carriers (c.a. = carrier added). Since different nuclides have an impact on the radiochemical and biological properties of the tracer, our experiments were designed to further elucidate the mechanisms and structural prerequisites for bone uptake. We labelled the commercially available Multibone kit with [111In] and [99mTc] using different carriers, e.g. indium and rhenium, to form "cross complexes". In the case of [188Re] we compiled minor modifications to this kit for the first time allowing the simple preparation of [188Re]-EDTMP in the departments without on-site radiopharmacy.