Definition

A radioconjugate composed of the amphiphilic camptothecin (CPT) prodrug EB-ss-CPT, labeled with the radioisotope gallium Ga 68, with potential use as a tracer for tumor cells during positron emission tomography (PET). EB-ss-CPT is composed of CPT conjugated, via a redox-responsive disulfide linker, to an albumin-binding Evans blue (EB) derivative. Upon administration of gallium Ga 68 EB-ss-CPT, the EB-ss-CPT moiety binds to endogenous albumin and the resulting albumin-bound nanocomplex accumulates in tumor cells. This allows the detection and visualization of tumor cells upon PET imaging.