Thyroglobulin measurement vs iodine 131 total-body scan for follow-up of well-differentiated thyroid cancer.

Measurement of the serum thyroglobulin level may be more sensitive than total-body scan using sodium iodide 131 for detecting recurrences from well-differentiated thyroid cancer. We have evaluated the merit of these two methods through a retrospective chart review of patients followed up at the Milton S. Hershey Medical Center, Hershey, Pa. We found that in 17 (45%) of 38 follow-up visits, the presence of interfering antibodies prevented the measurement of serum thyroglobulin levels. Furthermore, such determination was less sensitive than iodine 131 total-body scan in detecting residual thyroid tissue and/or cancer in the neck area. We concluded that iodine 131 total-body scan is the preferable method of follow-up, particularly when the goal of therapy is complete ablation of thyroid tissue.