Efficacy of radioiodine therapy in the treatment of elevated serum thyroglobulin in patients with differentiated thyroid carcinoma and negative whole-body iodine scan

Abstract

We recommend that in differentiated thyroid carcinoma patients with elevated thyroglobulin and negative WBS, at least one course of radioiodine therapy should be undertaken and if reduction or normalization of serum thyroglobulin is not achieved, repeated courses of radioiodine therapy are not logical and other therapeutic methods should be applied.

Characteristics and prognosis of patients with thyroglobulin-positive and radioactive iodine whole-body scan-negative differentiated thyroid carcinoma

“…Of note, 30-50% of Tg+/WBS− patients show decreased Tg values spontaneously or in response to RAI after diagnostic WBS showing negative results (5,10,11). In the present study, 14 of 42 patients who showed detectable Tg before the latest diagnostic or therapeutic RAI administration were controlled to <1.0 ng/ml with TSH suppression therapy or only L-T4 replacement, and none of them recurred during the observation period.…”

Guidelines for the management of thyroid cancer

“…FDG‐PET‐CT is useful in this setting, particularly if the Tg is significantly increased. FDG is concentrated by metabolically active thyroid cells and uptake indicates histologic transformation from low to high risk poor prognosis tumours, as FDG uptake reflects dedifferentiation.…”

Practice Trends in Patients with Persistent Detectable Thyroglobulin and Negative Diagnostic Radioiodine Whole Body Scans: A Survey of American Thyroid Association Members

“…Subsequent reports demonstrated that more than half of such patients, if given an empiric therapeutic dose of 131 I, had visible uptake on a post-therapy WBS, and the median percentage of positive scans was 57% (range 0-94%) (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). Most lesions were in the cervical lymph nodes, but thyroid bed uptake (which could represent normal thyroid remnant) and distant metastases were also detected.…”

“…In the late 1980s to mid-1990s, several authors reported that if given a therapeutic dose of 131 I, 64-94% of patients with positive serum Tg but negative DxWBS (Tg + /WBS -) would have detectable residual thyroid cancer in a post-therapy 131 I scan (2)(3)(4)(5). Numerous subsequent reports confirmed these early results, and the median percentage of positive post-therapy 131 I-WBS was 57% (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). While many advocated the use of an empiric dose of 131 I, others cautioned against its routine use, given the side effects and unproven benefits (10,(17)(18)(19)(20).…”