AUTHOR=Klain Michele , Pace Leonardo , Zampella Emilia , Mannarino Teresa , Limone Simona , Mazziotti Emanuela , De Simini Giovanni , Cuocolo Alberto 

TITLE=Outcome of Patients With Differentiated Thyroid Cancer Treated With 131-Iodine on the Basis of a Detectable Serum Thyroglobulin Level After Initial Treatment

JOURNAL=Frontiers in Endocrinology

VOLUME=Volume 10 - 2019

YEAR=2019

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2019.00146

DOI=10.3389/fendo.2019.00146

ISSN=1664-2392

ABSTRACT=Objective: In patients with differentiated thyroid cancer (DTC) showing raising serum thyroglobulin (Tg) after total or near-total thyroidectomy and 131I remnant ablation an empiric 131I therapy may be considered. Data on outcome after empiric therapy in this setting did not show a clear evidence of improved survival. We assessed the efficacy of such empiric 131I therapy and also evaluated the outcome of these patients.
Methods: A total of 100 patients with DTC showing raised Tg level during follow-up after thyroidectomy and 131I ablation were treated with a further 131I therapy (6.1 ± 1.7 GBq). Whole-body scan (WBS) was performed 5-7 days after therapy. Tg value at 12 months was considered as an indicator of treatment response: ≤1.5 ng/ml complete remission (CR), >50% decrease partial remission (PR), higher than pre-therapy progression disease (PD), all other cases stable disease (SD). Patients were followed-up for 96 ± 75 months.
Results: After 12 months, 62% of patients were in CR, 16% in PR, 8% in SD and 14% in PD. WBS was positive in 41% of patients and negative in 59% (P = NS). Among patients with local recurrences at WBS, 89% showed either CR or PR, while 71% of patients with distant metastases were in SD or PD (P < 0.001). Distant metastases at WBS (P < 0.05), CR (P < 0.0001) and CR + PR (P < 0.0001) were predictors of both progression free survival and overall survival.
Conclusion: There is a beneficial effect of 131I therapy on outcome of patients treated on the basis of elevated Tg value. In these patients, survival is affected by achievement of CR or PR at 12 months evaluation after 131I therapy and by presence of distant metastases at WBS.