Application of nanoparticles in nuclear medicine has aimed to develop diagnosis and therapeutic techniques. Cerium oxide nanoparticles
(CNPs) are expected to be useful for protection of healthy tissue from radiation-induced harm and could serve therapeutic
function. Among a variety of cerium radioisotopes, 137mCe (T1/2 = 34.4 h, IT (99.22%), β+ (0.779%)) could be a novel candidate radionuclide in the field of diagnosis owing to its appropriate half-life, 99.91% natural
abundance of target and its intense gamma line at 254.29 keV. In this study, 137mCe excitation function via the natLa(p,3n) reaction was calculated by TALYS-1.2 and EMPIRE-3 codes. The excitation function calculations demonstrated that the
natLa(p,3n)137mCe reaction leads to the formation of the 136/138Ce isotopic contamination in the 22–35 MeV energy range. Interestingly, the isotopic impurities of 137mCe could serve radio protector function. Overall results indicate that the cyclotron produced 137mCeO2 nanoparticles by irradiation of a target encompassing lanthanum oxide nanoparticles could be a potent alternative for conventional
diagnostic radionuclides with simultaneous radioprotection capacity.