Optimization of estimating 131I effective half-life in patients with Graves' disease / 中华核医学与分子影像杂志

ABSTRACT

Objective To explore optimized method of estimating 131I effective half-life(EHL) in patients with Graves' disease(GD).Methods The EHL was obtained by measuring thyroid radioactive iodine uptake (RAIU) of 126 patients (32 males,94 females,average age (38.47± 11.49) years) with GD at 4,24,48,96,120,144,168,192 and 216 h.Two-sample t test,bivariate correlation analysis and curve estimation were used for statistical analysis.Results The EHL of 126 patients was 0.5-7.5 (4.70±1.46) d.The EHL was 3.0-7.5(5.25±1.01) d and 0.5-6.0(3.24±1.52) d in group A (94 patients,without advanced peak of RAIU) and group B (32 patients,with advanced peak of RAIU),respectively,and the difference between the 2 groups was significant (t =8.499,P＜0.01).The EHL had no significant correlation with RAIU4h/RAIU24h(r=-0.177,P＞0.05) in group A,while it had negative correlation with RAIU4h/RAIU24h in group B (r =-0.724,P＜0.01).In group A,the EHL of patients with RAIU24h/RAIU48h ＞100％ was 3.0-7.5 (5.11 ±0.98) d,the EHL of patients with RAIU24h/RAIU48h ≤ 100％ was 4.0-7.0(5.91±0.94) d (t=3.141,P＜0.01).In group B,when RAIU4h/RAIU24h+RAIU24h/RAIU48h was used as the independent variable in S curve model to estimate the EHL,the result was the best (R2=0.930,F=397.22,both P＜0.01,b0 =-3.038 0,b1 =9.659 4).Conclusions In order to optimally estimate EHL,patients should be grouped according to 131I turnover.In patients with advanced peak of RAIU,the EHL should be calculated by using formula of (RAIU4h/RAIU24h +RAIU24h/RAIU48h).If no advanced peak of RAIU exists,patients should be further divided according to RAIU24h/RAIU48h ＞ 100％ or RAIU24h/RAIU48h ≤100％,and the EHL mean value of each group is taken as the estimated EHL.