Abstract
Increased bone metabolism can be visualized by PET as well as SPECT. For SPECT, (99m)Tc is predominately used as bisphosphonate complex.
In contrast to SPECT, PET offers a higher spatial resolution and owing to the (68)Ge/(68)Ga generator an analog to the established (99m)Tc generator exists. Currently, the combination of novel bisphosphonates (BP) and macrocyclic chelators is studied worldwide.
For complexation of Ga(III) DOTA, NOTA and their derivatives are often used. DOTA bisphosphonates are also able to coordinate (177)Lu, which offers the possibility of developing theranostics by using [(68)Ga]NOTA-BP for PET/CT and (177)Lu-labeled analogs for an individualized therapy.
This overview describes the status quo of diagnosing bone metastases using [(68)Ga]NO2APBP and [(68)Ga]BPAMD as well as the successful application of [(177)Lu]BPAMD for therapy. The new PET tracers are compared to [(99m)Tc]MDP and [(18)F]fluoride and results concerning the visualization of bone metastases using [(68)Ga]NO2APBP are presented in comparison to [(68)Ga]HBED-PSMA.
In terms of therapy, available ex vivo data is compared to (223)Ra. Finally, an outlook is provided on further developments providing new (68)Ga- and (177)Lu-labeled bisphosphonates offering improved pharmacological properties.