Preablation stimulated thyroglobulin is a good predictor of successful ablation in patients with differentiated...

To evaluate the predictive capacity of clinical and laboratory variables in relation to the success of ablation. The variables studied were as follows: thyroglobulin (Tg) in hypothyroidism, before ablation; age; gender; type of carcinoma (papillary or follicular); the tumor stage; the administered activity of I; and the whole-body scan 7 days after ablation.

Retrospective review of the medical records of all patients who were admitted to the therapeutic room to undergo treatment with I, from 1998 to 2007. Of the records reviewed, 96 patients fulfilled the inclusion criteria and had no exclusion criteria. A negative whole-body scan and Tg in hypothyroidism <2 ng/mL, after 6 to 12 months of treatment, were considered as successful ablation.

The dosage of Tg in hypothyroidism, measured before the ablation, was the only independent predictor of ablation success in multivariate analysis (P < 0.0001), and the optimal cutoff for this cohort was 18 ng/mL. On univariate analysis, the high-risk staging was predictor of ablation failure.

The measurement of Tg in hypothyroidism before ablation might be useful if added to the routine evaluation of patients before I treatment because it was a good predictor of successful ablation.