Luo H, et al. - A cohort study was performed to compare the effectiveness of three methods of preparation for radioactive iodine (RAI) therapy in metastatic differentiated thyroid cancer (DTC): thyroid hormone withdrawal (THW), THW with pre-treatment with lithium (Li) (THW+Li), and recombinant human TSH (rhTSH). Findings revealed that the older age was correlated with shorter overall survival (OS). On the other hand, disease burden affects OS and progression-free survival (PFS) in these patients. However, longer PFS was linked to the presence of distant metastases limited to the lungs only. It was noted that the method of preparation for RAI therapy did not affect the outcome.