TG and thyroid gland disorder: 131I therapy has been used in clinical treatment of thyroid disorder for 80 years.21 Overwhelmingly, 131I therapy has been guided by several factors such as information derived from surgical histopathology, radioiodine scintigraphy, and TSH or Tg levels in previous studies.22,23 In our study, sex, risk stratification, TNM-N, RAIU%, Tgon, Tgoff, TSHoff, and courses of 131I therapy before the current course of 131I therapy, were all identified as significant factors for predicting treatment response to 131I therapy.