In Search of an Unstimulated Thyroglobulin Baseline Value in Low-Risk Papillary Thyroid Carcinoma Patients Not Receiving Radioactive Iodine Ablation

Background: The clinical use of serum thyroglobulin (Tg) as a tumor marker in papillary thyroid cancer (PTC) patients following total thyroidectomy continues to evolve, due in part to the introduction of more sensitive (second generation) Tg immunometric assays (Tg2GIMA, functional sensitivity ≤0.10 ng/mL), and the implementation of new recommendations against radioactive iodine ablation (RAIA) for patients at the lowest risk of recurrence. As a result, there is a need to establish the optimal timing and interpretation of serum Tg values while on levothyroxine-induced suppression of thyrotropin (TSH) in thyroidectomized PTC patients with a thyroid remnant. This study examines the pattern of decline and eventual baseline value of unstimulated Tg (uTg) concentrations following total thyroidectomy in patients with low-risk PTC who did not receive RAIA. Methods: The medical records of consecutive patients with thyroid cancer seen at the Los Angeles County+USC Medical Center were retrospectively reviewed. Seri...