Same-day imaging using small proteins

Imaging of expression of therapeutic targets may enable stratification of patients for targeted treatments. The use of small radiolabeled probes based on the heavy-chain variable region of heavy-chain–only immunoglobulins or nonimmunoglobulin scaffolds permits rapid localization of radiotracers in tumors and rapid clearance from normal tissues. This makes high-contrast imaging possible on the day of injection. This mini review focuses on small proteins for radionuclide-based imaging that would allow same-day imaging, with the emphasis on clinical applications and promising preclinical developments within the field of oncology.