1. Patients with a history of DTC | 1. Age < 18 y |
2. After complete thyroidectomy and ablation of functional remnants with 131I | 2. Pregnancy |
3. Planned for blind treatment with high activity of 131I based on biochemically suspected recurrence, defined as a Tg-level above 2.0 ng/mL | 3. Incapacitated subjects |
4. Ultrasonography of the neck performed < 2 mo before inclusion | 4. Contrast-enhanced CT performed < 4 mo before inclusion |
| 5. 131I therapy performed < 12 mo before inclusion |
| 6. Indication for other therapy modality (i.e., surgery in case of a positive ultrasonography, radiotherapy, embolization, or chemotherapy) |