Follow-up
Follow-up visits included evaluation of symptoms, physical examination, blood tests, cancer biomarkers, thyroid function tests, endoscopy, CT or magnetic resonance imaging (MRI) scans of the neck and thorax, and ultrasonography of the cervical and abdominal regions. These were accomplished 1 month after the completion of RT, every 3 months in the first 2 years, every 6 months between years 3 and 5, and once a year thereafter.