Currently, receptor based radiopharmaceuticals have received great attention in molecular imaging and radiotherapy of cancer,
and provide a unique tool for target-specific delivery of radionuclides to pathological tissues. In this context, receptor binding peptides
represent an attractive class of target vectors for Nuclear Medicine purposes. The rich chemistry of the group 7 elements elaborated in
past years, has allowed the development of different procedures for the preparation of radiolabeled peptides in high yield. This, joint to
the use of solid-phase peptide synthesis, has opened the possibility to explore new strategies for approaching the design of new class of
radiolabeled receptor-targeted peptides, and to create new versatilities in targeting vehicle design e.g. in synthesis of metal-cyclized
peptides or of multivalent targeting agents.
This review provides an overview on several aspects of the development of new 99mTc/188Re-peptide based target specific
radiopharmaceuticals, in particular on the synthetic strategies employed for modifying molecular vectors, and the application of the
different metal-cores and/or building block for preparing high specific activity agents.