POSITRON EMISSION TOMOGRAPHY USING GALLIUM-68 CHELATES

摘要

A method of delivering Ga-68 to a target site is effected by administering a bi-specific antibody which specifically binds via a primary binding site to a substance produced by or associated with the target site and which specifically binds via a secondary binding site to a subsequently administered chelate-Ga-68 complex, and allowing the antibody to localize at the target site; optionally administering a clearing agent to clear non-localized bi-specific antibody rapidly from circulation; and administering a chelate-Ga-68 complex comprising Ga-68 chelated to Ac-Phe-Lys(DTPA)-Tyr-Lys(DTPA)-NH2 and allowing the chelate-Ga-68 complex to localize at the target site via specific binding by the secondary binding site of the bi-specific antibody. The targeted complex then can be used for PET imaging to give highly resolved images. Alternatively, the Ac-Phe-Lys(DTPA)-Tyr-Lys(DTPA)-NH2 can be conjugated to a targeting antibody fragment and used to elute Ga-68 from a generator, after which it is infused into a patient for direct targeting of the Ga-68 for PET imaging. Reagents and methods of making and using them also are provided.