A retrospective study of 270 differentiated-thyroid-cancer patients in remission after surgery and radioactive iodine evaluated thyroglobulin doubling time and velocity during TSH suppression. Only three recurrences occurred, making proposed thresholds exploratory rather than standalone clinical rules.
Key findings
- Three patients (1.1%) recurred. Exploratory cutoffs of Tg-DT≤1 year and TgV≥0.1 ng/mL/year yielded sensitivity 66.7% (95% CI 9.4-99.2), specificity 100% (98.6-100), and accuracy 99.6% (97.9-99.9). Mean recurrence-free survival was 2.8 versus 9.9 years (p
Why this matters globally
Longitudinal kinetics may add information beyond a single Tg value in low-risk follow-up and help target intensified surveillance if thresholds are externally validated with harmonized assays.
Thai researcher contribution
The Siriraj Hospital, Mahidol University nuclear-medicine team used long-term real-world follow-up to address a consequence of successful treatment: detecting rare recurrence without unnecessary surveillance.
Limitations to consider
This is a single-center retrospective cohort from 2007-2011 with only three events. ROC cutoffs risk overfitting, sensitivity is highly uncertain, and accuracy is inflated by the rarity of recurrence. Independent validation across Tg assays and anti-Tg-antibody status is essential.