@article {Fast732, author = {S{\o}ren Fast and Viveque Egsgaard Nielsen and Peter Grupe and Steen Joop Bonnema and Laszlo Heged{\"u}s}, title = {Optimizing 131I Uptake After rhTSH Stimulation in Patients with Nontoxic Multinodular Goiter: Evidence from a Prospective, Randomized, Double-Blind Study}, volume = {50}, number = {5}, pages = {732--737}, year = {2009}, doi = {10.2967/jnumed.108.060152}, publisher = {Society of Nuclear Medicine}, abstract = {Prestimulation with recombinant human thyroid-stimulating hormone (rhTSH) augments radioiodine 131I therapy for benign nontoxic multinodular goiter. The purpose of this study was to determine the optimal time interval between rhTSH and 131I administration to enhance thyroid radioactive iodine uptake (RAIU). Methods: Patients were randomized, in a 2-factorial design, to receive either a 0.1-mg dose of rhTSH (n = 60) or placebo (n = 30) and to a time interval of 24, 48, or 72 h before 131I administration. The rhTSH- or placebo-stimulated RAIU study was performed at 4 wk after a baseline RAIU assessment in a tertiary referral center at a university hospital. A total of 90 patients (78 women; median age, 52 y; range, 22{\textendash}83 y) referred to 131I therapy for symptomatic nontoxic goiter (median goiter volume, 63 mL; range, 25{\textendash}464 mL) were included in the study. Change in thyroid RAIU was determined at 24 and 96 h after 131I tracer administration. Results: In the placebo subgroups, RAIU did not change significantly from baseline. The mean ({\textpm}SE) 24-h RAIU increased from 33.8\% {\textpm} 2.3\% to 66.0\% {\textpm} 1.8\% (111.2\% increase) with a 24-h interval, from 36.8\% {\textpm} 2.1\% to 64.6\% {\textpm} 2.7\% (83.3\% increase) with a 48-h interval, and from 33.0\% {\textpm} 2.7\% to 49.6\% {\textpm} 2.5\% (62.4\% increase) with a 72-h interval. All within-group changes were highly significant (P \< 0.001). The effect was negatively correlated with initial RAIU (r = -0.703, P \< 0.001). The increase in 24- and 96-h RAIU was significantly higher in the rhTSH/24-h group than it was in the rhTSH/72-h group (P = 0.023 and 0.012, respectively) and insignificantly higher than in the rhTSH/48-h group (P = 0.37 and 0.26, respectively). Conclusion: The effect of rhTSH on thyroid RAIU is most pronounced when administered 24 h before 131I administration and declines with longer time intervals. Whether there is a similar time dependency for goiter reduction after rhTSH-stimulated 131I-therapy remains to be clarified.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/50/5/732}, eprint = {https://jnm.snmjournals.org/content/50/5/732.full.pdf}, journal = {Journal of Nuclear Medicine} }