ePoster #6 | Negative thyroglobulin as an ancillary method of follow-up for low risk differentiated thyroid cancer after total thyroidectomy
Clinical Science | Endocrine
NEGATIVE THYROGLOBULIN AS AN ANCILLARY METHOD OF FOLLOW-UP FOR LOW RISK DIFFERENTIATED THYROID CANCER AFTER TOTAL THYROIDECTOMY
A Attia, M Omar, M aboueisha, E Toraih, E Kandil
ePoster Presenter: Abdallah Attia MD, Tulane School of Medicine
Background: The American Association of thyroid (ATA) recommend a routine cervical ultrasound (CUS) as a plan of management for papillary thyroid cancer follow-up, and it is usually done regardless of non-stimulated thyroglobulin (Tg) levels.
Objectives: We sought to investigate whether there is a clinical benefit from the routine US in low-risk papillary thyroid carcinoma (PTC).
Methods: We conducted a retrospective study using electronic medical records of Patients with a history of PTC with post-operative negative thyroglobulin levels. The ultrasound’s diagnostic value was assessed based on fine-needle aspiration as a gold standard, with sub-group analysis comparing low-risk and high-risk recurrence patients.
Results: A total of 223 patients underwent a total of 767 CUS; of them, 181 were females (70.4%), TG panel was negative in 626 of which CUS was true negative in 478 (76.35%), true positive 9 (1.43%), and false-positive was 139 (22.22%) with a positive predictive value of 6.08% (CI= 5.30% to 6.97%) and accuracy of 77.80% (CI= 74.33% to 80.99%). On subgroup analysis, the Positive predictive value was significantly lower in low-risk recurrence patients 2.60% (CI= 2.14% to 3.14%) in comparison with intermediate and high-risk patients 10.00%(CI=7.66%to12.95%). p < 0.001.
Conclusion: Routine comprehensive ultrasound showed no additional benefit to monitoring PTC following total thyroidectomy when TG level is undetectable. Comprehensive neck ultrasound in these patients is associated with a high false-positive rate, leading to neck lymph nodes’ unnecessary biopsies.