%0 Journal Article
%T Comparison of 1.1 GBq and 2.2 GBq Activities in Patients with Low-Risk Differentiated Thyroid Cancer Requiring Postoperative 131I Administration: A Real Life Study.
%A Campennì A
%A Ruggeri RM
%A Garo ML
%A Siracusa M
%A Restuccia G
%A Rappazzo A
%A Rosarno H
%A Nicocia A
%A Cardile D
%A Ovčariček PP
%A Baldari S
%A Giovanella L
%J Cancers (Basel)
%V 15
%N 9
%D 2023 Apr 22
%M 37173884
%F 6.575
%R 10.3390/cancers15092416
%X <B>OBJECTIVE: </B>To compare the efficacy of low and moderate 131I activities in low-risk differentiated thyroid carcinoma (DTC) patients requiring postoperative thyroid remnant ablation in a real-world clinical setting.<BR><B>METHODS: </B>We retrospectively reviewed the records of 299 low-risk DTC patients (pT1-T2, Nx(0) Mx) who had undergone (near)-total thyroidectomy followed by 131I therapy, using either low (1.1 GBq) or moderate (2.2 GBq) radioiodine activities. The response to initial treatments was evaluated after 8-12 months, and patient responses were classified according to the 2015 American Thyroid Association guidelines.<BR><B>RESULTS: </B>An excellent response was observed in 274/299 (91.6%) patients, specifically, in 119/139 (85.6%) and 155/160 (96.9%) patients treated with low and moderate 131I activities, respectively (p = 0.029). A biochemically indeterminate or incomplete response was observed in seventeen (22.2%) patients treated with low 131I activities and three (1.8%) patients treated with moderate 131I activities (p = 0.001). Finally, five patients showed an incomplete structural response, among which three and two received low and moderate 131I activities, respectively (p = 0.654).<BR><B>CONCLUSIONS: </B>When 131I ablation is indicated, we encourage the use of moderate instead of low activities, in order to reach an excellent response in a significantly larger proportion of patients, including patients with the unexpected persistence of the disease.