TH and neoplasm: Among others, these include the best method of preparation (thyroid hormone (TH) deprivation vs. recombinant human Thyroid Stimulating Hormone (rhTSH)), the amount of 131I used (low vs. high doses) depending on tumor risk stratification, assessment of post-operative disease status, precise definition of successful therapy, the radioisotopes chosen in diagnosis to avoid stunning, the use of personalized dosimetry, the management of refractory RAI cases, and the evaluation of putative side effects in the risk–benefit ratio of RAI to optimize the decision-making process.