With the extensive applications of nuclear energy in the military, scientific research, and medical fields, radiological medicine has developed into a significant discipline. So far, studies of radiology have been conducted mostly using cell and animal models, both of which have limitations. Organoids, as 3D in vitro culture systems derived from tissue stem cells, have filled the gap left by these conventional models. They have been widely applied in review, disease research, drug development, and cancer modeling since their structures, functions, and genetic characteristics are akin to those of primary tissues. This review presents the applications of organoid models of various organ types in radiotherapy, as well as the limitations and prospects of organoids.