Adjuvant radioactive therapy after reoperation for locoregionally recurrent papillary thyroid cancer in patients who initially underwent total thyroidectomy and high-dose remnant ablation.

CONTEXT

Some patients have elevated stimulated thyroglobulin (sTg) concentrations after reoperation for locoregionally recurrent/persistent papillary thyroid cancer (PTC). Little is known, however, about the efficacy of adjuvant radioactive iodine (RAI) therapy in these patients.

OBJECTIVE

The objective of the study was to evaluate the efficacy of adjuvant RAI therapy in patients with elevated sTg after reoperation for locally recurrent/persistent PTC.

DESIGN AND SETTINGS

This was a retrospective observational cohort study in a tertiary referral hospital.

PATIENTS

We evaluated 45 consecutive patients with sTg greater than 2 ng/ml after reoperation for locoregionally recurrent PTC, all of whom had previously undergone initial total thyroidectomy followed by high-dose RAI remnant ablation. Of these 45 patients, 23 received adjuvant RAI therapy (adjuvant group) and 22 did not (control group).

MAIN OUTCOME MEASURES

Main outcome measures included changes in sTg concentration after reoperation and disease-free survival.

RESULTS

Over time, there were no significant differences in mean sTg concentration in the adjuvant (P = 0.35) and control (P = 0.74) groups. Only 15% of patients in the adjuvant group and 33% in the control group showed a greater than 50% decrease in sTg level from baseline. There were no between-group differences in changes (P = 0.83) or percent decrease (P = 0.97) in sTg concentration and no difference in clinical recurrence-free survival (P = 0.20).

CONCLUSION

In patients who still have elevated sTg after reoperation for locally recurrent/persistent PTC, adjuvant RAI therapy compared with no additional RAI therapy resulted in no significant differences in the subsequent sTg changes or the recurrence-free survival.