**3.2.3 I-124**

I-124 is a proton-rich isotope of iodine produced in a cyclotron by numerous nuclear reactions and it decays to Te-124 with a half-life of 4.18 days. Its modes of decay are: 74.4% electron capture and 25.6% positron emission. It emits gamma radiation with energies of 511 and 602 keV.(Rault, Vandenberghe et al. 2007)

I-124 is administered intravenously with activities of 0.5–2.0 mCi for detection of metastatic lesions or assessment of the radiation dose related to I-131 therapy.


Table 3. Advantages and disadvantages according to the types of radioiodine.(Nostrand, Bloom et al. 2004)
