A radioconjugate composed of the insulin-like growth factor 1 receptor (IGF-1R) binding agent CPD-1028 and conjugated to the radionuclide iodine I 124, with potential tumor imaging properties upon positron emission tomography/computed tomography (PET/CT). Upon administration, iodine I 124 CPD-1028 targets and binds to IGF-1R-expressing tumor cells. Upon PET/CT imaging, the iodine I 124 moiety can be visualized and the quantity of IGF-1R-expressing tumor cells can be assessed. IGF-1R, a receptor tyrosine kinase overexpressed in a variety of human cancers, plays a significant role in the stimulation of cellular proliferation, oncogenic transformation, and the suppression of apoptosis.