The first classic theranostic agent, radioactive iodine was used in the treatment of differentitated thyroid cancer (DTC) and it has an important role in the good prognosis of DTC even nowadays. I-131 provides a specific, molecular targeted therapy through the active uptake of iodide by sodium iodide symporter. The development of other theranostics also aimed the personalized therapy with minimal side effects and optimal therapeutic efficacy. The incidence of DTC which basically has good prognosis is increasing rapidly worldwide. This required the modification of guidelines to avoid the overtreatment of the disease, in the direction of less radical therapy. Currently, new pathological classification and staging systems were reported. The present work summarizes the new recommendations in the management of DTC, focusing on the indications of radioiodine therapy and reviewing the proposal of the Hungarian consensus conference.