One hundred and fifty-seven patients with Graves' disease treated with 131I from July 2001 to March 2003 were studied retrospectively. According to the thyroid function one year after 131I therapy, the patients were divided into 3 groups: remission group with normal FT3, FT4, partial remission group with above normal levels of FT3, FT4, and hypothyroid group with lowered levels of FT3, FT4. Prior to 131I treatment the thyroid-stimulating hormone receptor antibody (TRAb) was positive in 88.5% of the patients. After the therapy, TRAb levels rose transiently and reached the peak within 3-6 months and then dropped gradually thereafter. The weight of pretreatment thyroid, high levels of TRAb (≥405 U/L) and FT3, FT4 were predictors for the outcome of treatment.

Three hundred patients with Graves′ disease (GD) were analysed according to clinical data, which showed a negative correlation between thyroid 131 I turnover and effective half life, suggesting that 131 I turnover is an important parameter for GD therapy of 131 I dose calculation, and a higher cure rate is found in GD patients whose 131 I turnover is less than 1.

Objective To investigate the change of serum Tg levels of DTC patients with positive stimulated Tg (Tg ≥ 10.00 μg/L),negative 131I-diagnostic whole body scan(Dx-WBS) and no distant metastasis 6 months after initial 131I therapy.Methods Fifty-six DTC patients (20 males,36 females,average age 43.11 (21-70) y) with intermediate or low risk of recurrence according to American Thyroid Association (ATA) guideline were enrolled into the retrospective study.All patients were grouped according to stimulated Tg level after initial 131I therapy:group with positive Tg (Tg+ group,n =19) and group with negative Tg (Tgˉ group,n=37).Changes of suppressed Tg at 1 year and 2.5 years (Tg1ysup and Tg2.5ysup) after initial therapy were compared between the two groups.Serum TSH level,TgAb level,neck ultrasound and chest CT results were also evaluated.The two-sample t test and x2 test were used for statistical analysis with SPSS 17.0.Results Stimulated Tg and Tglysup levels in Tg+ group were remarkably higher than those in Tgˉ group:(24.27±4.10) μg/L vs (2.73±3.01) μg/L,t=7.191,P＜0.05(6 months after initial 131I therapy) ; (2.21±0.55) vs (0.48±0.10) μg/L,t=3.102,P＜0.05(1 year after initial 131I therapy),respectively.In Tg+ group,suppressed Tg level decreased with time in 68.4％ (13/19) of patients,of whom the Tg2.5ysup level was much lower than Tglysup level ((0.53±0.15) μg/L vs (1.38±0.50) μg/L).Tg2.5sup level in Tg+ group became comparable to that in Tgˉ group ((1.44±0.52) μg/L vs (0.38±0.07) μg/L; t =2.001,P＞0.05).In each group,one case of recurrence with suppressed Tg of 1.4 μg/L and 0.1 μg/L respectively,was observed using neck ultrasound after 2 years of follow-up.Conclusions Serum Tg levels decreased with time for Tg+/131I-Dx-WBS-DTC patients with intermediate or low risk of recurrence.It might not be necessary to follow up these patients with Tg and 131 I-DxWBS after 6 months of initial 131I therapy.