High level of Thyroglygobin


My sister went a thyroidectomy and after that she underwent radio active iodine treatment 6 months before.Now she had her utra sound scanning in which 2 nodes were found out in the lymph nodes.and also in the blood test thyroglobulin was high (239).But in the full body scan nodes were not seen.To make it more clear FDG pet scan was also done in which the cervical lymph nodes in right level 3 & 6 were seen.