The potential of radiolabeled chemotherapeutics in tumor diagnosis: Preliminary investigations with 68Ga-gemcitabine

: Preclinical Research & Development Gemcitabine, a nucleoside analog, is a well-known chemotherapeutic drug that is used either alone or with other agents to treat a wide variety of cancers. The aim of the present work was to evaluate the potential of 68 Ga-labeled gemcitabine for its application in positron emission tomography (PET) imaging of tumorous lesions. Gemcitabine was coupled with p-NCS-benzyl-DOTA in order to facilitate radiolabeling with 68 Ga. The gemcitabine-p-NCS-benzyl-DOTA was radiolabeled with 68 Ga, obtained from a 68 Ge/68 Ga radionuclide generator. The radiolabeled product was characterized by high performance liquid chromatography (HPLC) and its tumor specificity was evaluated by biodistribution studies in Swiss mice bearing fibrosarcoma tumors. Preliminary bioevaluation study showed good tumor uptake within 1 hr post-administration [2.5% Injected Activity (IA) per g of tumor] with rapid renal clearance (>90% IA) and a high tumor to muscle ratio. 68 Ga-gemcitabine may have potential as a PET agent for tumor imaging.