NODAGA-LM3 can be labeled by 68 Ga for PET imaging. 68 Ga-NODAGA-LM3 is a SSTR2 antagonist, and can be used for imaging of SSTR positive paragangliomas. NODAGA-LM3 can be labeled with [68Ga] for the synthesis/research of Radionuclide-Drug Conjugates (RDCs).