Table 3.

Major factors impacting decision making in radioiodine remnant ablation, 2009 ATA guideline [2].

Factors	Description	Expected Benefit
		Decreased risk of death	Decreased risk of recurrence	May facilitate initial staging and followup	RAI ablation usually recommended	Strength of evidence
T1	≤1 cm, intrathyroidal or microscopic multifocal	No	No	Yes	No	E
	1-2 cm, intrathyroidal	No	Conflicting data	Yes	Selective use	I
T2	>2–4 cm, intrathyroidal	No	Conflicting data	Yes	Selective use	C
T3	>4 cm,
	<45 years	No	Conflicting data	Yes	Yes	B
	≥45 years	Yes	Yes	Yes	Yes	B
	Any size, any age, minimal extrathyroidal extension	No	Inadequate data	Yes	Selective use	I
T4	Any size with gross extrathyroidal extension	Yes	Yes	Yes	Yes	B
NX, N0	No metastatic nodes documented	No	No	Yes	No	I
N1	<45 years	No	Conflicting data	Yes	Selective use	C
	>45 years	Conflicting data	Conflicting data	Yes	Selective use	C
M1	Distant metastases present	Yes	Yes	Yes	Yes	A