Table 2.

Evaluation of the Response to the Treatment with Radioiodine

Response	Definition
CR	(i) Disappearance of all target and nontarget lesions; (ii) Reduction of lymph node short axis to <1 cm; (iii) Undetectable serum Tg both during suppression and after TSH stimulation.
PR	Decrease of 30% or more in the sum of diameters of target lesions, taking as a reference the baseline sum diameter.
SD	Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD or non-PD/non-CR for nontarget disease
PD	At least a 20% increase in the sum of diameters of target lesions taking as a reference the smallest sum on the study and an increase of at least 5 mm or appearance of one or more new lesions.

Source: Eisenhauer et al. (12).

CR, complete response; PD, progressive disease; PR, partial response; SD, stable disease; Tg, thyroglobulin.