TG and thyroid cancer: As for the optimal dose of RAI therapy needed in those patients at low risk, a recent randomized phase 3 trial compared two thyrotropin stimulation methods (thyroid hormone withdrawal and the use of recombinant human thyrotropin) and two different radiodine doses (I131) (1.1 GBq and 3.7 GBq), in a 2-by-2 design, in 752 patients with low-risk differentiated thyroid cancer, where patients were included if they had pT1 (tumor diameter ≤ 1 cm) and N1 or Nx, pT1 (with tumor diameter >1 to 2 cm) and any N stage, or pT2N0 with absent distant metastasis.