Follow-up diagnostic radioiodine whole-body scintigraphy (DxWBS) is still advised for high-risk patients with differentiated thyroid cancer. The aim of this study was to evaluate the additional value of DxWBS to stimulated thyroglobulin measurement in high-risk patients.
Methods: The results of DxWBS and thyroglobulin measurements performed 6-12 mo after surgery and radioiodine thyroid remnant ablation in patients with differentiated thyroid cancer were retrospectively evaluated for 112 patients with high-risk features for recurrence (R3/T4 and N1).
Results: One patient had an undetectable thyroglobulin level, with DxWBS results suggestive of cervical recurrence. DxWBS was found to be false-positive. Of the patients with detectable thyroglobulin levels, the DxWBS results were negative in 65 and positive in only 8. The 6 patients positive for thyroglobulin antibody had negative DxWBS results. The remaining patients had an undetectable thyroglobulin level and negative DxWBS results.
Conclusion: Because undetectable stimulated thyroglobulin levels have a negative predictive value of 100%, DxWBS offers no information additional to recombinant human thyroid-stimulating hormone-stimulated thyroglobulin measurements in patients with high-risk differentiated thyroid cancer.