Table 1. Patient classification as ideal, appropriate, and inappropriate to initiate AS.

	Ideal	Appropriate	Inappropriate
Nodule characteristics	Solitary nodule Well-defined margisn cN0, cM0 No extrathyroidal extension	Multifocal Subcapsular location (not adjacent to RLN) Background US findings	Aggressive cytology Subcapsular location adjacent to RLN Obtuse angles between tumors and the trachea cN1, cM1 Evidence of extrathyroidal extension
Patient characteristics	>60 years Acceptance (also family members) Follow-up plans Life-threatening comorbidities “Minimalistic”	18 to 59 years Strong family history of PTC Childbearing potential	<18 years Unlikely to make follow-up No acceptance “Maximalist”
Medical team characteristics	Experienced multidisciplinary team High quality US Prospective data collection Reminder program to ensure follow-up	Experienced endocrinologist/surgeon US routinely available	US not available Little experience with thyroid cancer management

RLN: recurrent laryngeal nerve; US: ultrasound; PTC: papillary thyroid carcinoma.

Modified from: Brito and cols. (25).