Clinical & internal medicine DTC DTC recurrences Medicine PTMC RFA TI-RADS TIRAD TIRADS Thyroid Imaging Reporting and Data Systems (TIRADS) US-guided minimally invasive techniques artificial intelligence benign thyroid nodules biopsy cancer classification system contrast-enhanced ultrasound (CEUS) deep learning diagnosis elastosonography fine-needle fine-needle aspiration fine-needle aspiration biopsy follicular lesion of unknown significance follicular neoplasm follicular thyroid cancer follow-up long term machine learning medical imaging