Abstract:
Bone metastases, often a consequence of breast, prostate, and lung carcinomas, are
characterized by an increased bone turnover, which can be visualized by positron emission
tomography (PET), as well as single-photon emission computed tomography (SPECT).
Bisphosphonate complexes of 99mTc are predominantly used as SPECT tracers. In contrast
to SPECT, PET offers a higher spatial resolution and, owing to the 68Ge/68Ga generator, an
analog to the established 99mTc generator exists. Complexation of Ga(III) requires the use of
chelators. Therefore, DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid), NOTA
(1,4,7-triazacyclododecane-1,4,7-triacetic acid), and their derivatives, are often used. The combination
of these macrocyclic chelators and bisphosphonates is currently studied worldwide. The use of DOTA
offers the possibility of a therapeutic application by complexing the -emitter 177Lu. This overview
describes the possibility of diagnosing bone metastases using [68Ga]Ga-BPAMD (68Ga-labeled
(4-{[bis-(phosphonomethyl))carbamoyl]methyl}-7,10-bis(carboxymethyl)-1,4,7,10-tetraazacyclododec
-1-yl)acetic acid) as well as the successful application of [177Lu]Lu-BPAMD for therapy and the
development of new diagnostic and therapeutic tools based on this structure. Improvements
concerning both the chelator and the bisphosphonate structure are illustrated providing new 68Gaand
177Lu-labeled bisphosphonates offering improved pharmacological properties.
