ATA Guidelines Tools

DTC: Long-Term Management and Advanced Cancer Management 24 63. A) In ATA low-risk and intermediate-risk patients who have had remnant ablation or adjuvant therapy and negative cervical US, serum Tg should be measured at 6–18 months on thyroxine therapy with a sensitive Tg assay (<0.2 ng/ml) or after TSH stimulation to verify absence of disease (excellent response). (SR-M) B) Repeat TSH stimulated Tg testing is not recommended for low and intermediate risk patients with an excellent response to therapy. (WR-L) C) Subsequent TSH stimulated Tg testing may be considered in patients with an indeterminate, biochemical incomplete or structural incomplete response following either additional therapies or a spontaneous decline in Tg values on thyroid hormone therapy over time in order to reassess response to therapy. (WR-L) 64. Periodic serum Tg measurements on thyroid hormone therapy and neck ultrasonography should be considered during follow-up of patients with DTC who have undergone less than total thyroidectomy, and in patients who have had a total thyroidectomy but not RAI ablation. While specific cutoff levels of Tg that optimally distinguish normal residual thyroid tissue from persistent thyroid cancer are unknown, rising Tg values over time are suspicious for growing thyroid tissue or cancer. (SR-L) 65. A) Following surgery, cervical US to evaluate the thyroid bed and central and lateral cervical nodal compartments should be performed at 6–12 months and then periodically, depending on the patient's risk for recurrent disease and Tg status. (SR-M) B) If a positive result would change management, ultrasonographically suspicious lymph nodes 8–10 mm in the smallest diameter should be biopsied for cytology with Tg measurement in the needle washout fluid. (SR-L) C) Suspicious lymph nodes <8–10 mm in smallest diameter may be followed without biopsy with consideration for FNA or intervention if there is growth or if the node threatens vital structures. (WR-L) D) Low-risk patients who have had remnant ablation, negative cervical US, and a low serum Tg on thyroid hormone therapy in a sensitive assay (<0.2 ng/ml) or after TSH-stimulation (Tg <1 ng/ml) can be followed primarily with clinical examination and Tg measurements on thyroid hormone replacement. (WR-L) 66. After the first post-treatment WBS performed following RAI remnant ablation or adjuvant therapy, low-risk and intermediate-risk patients (lower risk features) with an undetectable Tg on thyroid hormone with negative antithyroglobulin antibodies and a negative US (excellent response to therapy) do not require routine diagnostic WBS during follow-up. (SR-M)

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