Iodine-124 (124I), a positron emission tomography (PET) radiotracer, can be used in a variety of PET applications, such as protein and antibody iodinations, as well as in the design and synthesis of new PET tracers. I-124 has the potential to improve the current clinical practice in the diagnosis and treatment of differentiated thyroid cancer (DTC). In addition, 124 PET/CT is a sensitive tool to detect some new lesions that are not visualized on the post-treatment I-131 scan. Recently published article has described that in order to I-124 used as a mainstream, this substance should be more commercially available and at a more chipper.