(68)Ga-BPAMD: PET-imaging of bone metastases with a generator based positron emitter

PurposeBone metastases are a serious aggravation for patients suffering from cancer. Therefore, early recognition of bone metastases is of great interest for further treatment of patients. Bisphosphonates are widely used for scintigraphy of bone lesions with ^99mTc. Using the ⁶⁸Ge/⁶⁸Ga generator together with a macroyclic bisphosphonate a comparable PET-tracer comes into focus.ProceduresThe bisphosphonate DOTA-conjugated ligand BPAMD was labelled with ⁶⁸Ga. [⁶⁸Ga]BPAMD was evaluated in vitro concerning binding to hydroxyapatite and stability. The tracer's in vivo accumulation was determined on healthy rats and bone metastases bearing animals by μ-PET.ResultsBPAMD was labelled efficiently with ⁶⁸Ga after 10 min at 100 °C. [⁶⁸Ga]BPAMD showed high in vitro stability within 3 h and high binding to hydroxyapatite. Consequently, μ-PET experiments revealed high accumulation of [⁶⁸Ga]BPAMD in regions of pronounced remodelling activity like bone metastases.Conclusions⁶⁸Ga BPAMD reveals great potential for diagnosis of bone metastases via PET/CT. The straight forward ⁶⁸Ga-labelling could be transferred to a kit-preparation of a cyclotron-independent PET tracer instantaneously available in many clinical sites using the ⁶⁸Ge/⁶⁸Ga generator.