Endocrine Abstracts

Aim: To investigate the efficiency of ultrasound surveillance in detecting papillary thyroid cancer recurrences in Dynamic Risk Stratification (DRS) subgroups.

Methods: The study included 477 patients with papillary thyroid cancer (PTC) who underwent total or completion thyroidectomy and were followed for at least three ultrasound scans (US). The patients were categorized into DRS subgroups based on their first-year therapy response. The reports of consecutive US following the initial assessment were analyzed retrospectively. The US findings of the residual thyroid tissue or lymph nodes were categorized as suspicious, indeterminate, or benign based on European Thyroid Association guideline criteria. The lymph nodes that did not meet these criteria were defined as non-specific lesions. In addition, the positive predictive value (PPV) and negative predictive value (NPV) of the follow-up ultrasound scans were calculated.

Results: The median surveillance time was 76 IQR [58-104] months. Nine recurrences were observed. The recurrence rate was 0.3% in the excellent response group. The maximum time to recurrence after the first-year assessment was one year in the excellent response group (ERG) and two years in the non-excellent response group (NERG). Out of 11 fine needle aspiration biopsies performed for atypical findings in ERG, one revealed metastasis (9.1%). This ratio was 100% for the structural incomplete response group. The cumulative PPV of ERG and NERG were 1.78% and 29.76%, respectively. Given the sole recurrence in ERG subgroup was observed in the first year of assessment, the PPV of the first periodic ultrasound scans was evaluated. It was 7.69% in ERG and 34.78% in NERG.

Conclusion: The findings from the present study suggest that patients with PTC who achieved excellent response may be followed with clinical examination and serum non-stimulated thyroglobulin level.