Preliminary imaging studies of [[61]Cu] diacetyl-bis [N[4]-methylthiosemi-carbazone] in normal and hypoxic tumor models

ABSTRACT

[[61]Cu] diacetyl-bis [N[4] -methylthiosemicarbazone] [[[61]Cu] ATSM] is a well-established hypoxia imaging tracer with simple production and significant specifity. In this work the accumulation of the tracer is studied in wild-type, necrotic and hypoxic fibrosarcoma tumors. [[61] Cu] ATSM was prepared using ATSM ligand and [[61]Cu] CuOAc followed by i.v. administration and imaging studies in wid-type rats and hypoxic fibrosarcoma-bearing mic.e [[61] Cu] ATSM with high radiochemical purity [>99%, HPLC, RTLC] was injected to wild-type rats as well as hypoxic and necrotic fibrosarcoma-bearing mice followed by imaging up to 3 hours. [[61] Cu] ATSM was mainly accumulated in liver, as well as kidney and bladder and less but still significant in brain of wild-type rats. A significant and hypoxia-specific tumor/non tumor ratio in hypoxic models was observed by co-incidence imaging 2h post inection, while in necrotic and 12-week tumor-induced mice very slight tumor uptakes were detected. [[61]Cu] ATSM is a positron emission tomography [PET] radiotracer for selective tumor hypoxia imaging from necrotic and proliferative tumors