Clinical research on radioiodine addition of low-doses of lithium carbonate in short-term treatment of Graves hyperthyroidism

Objective To explore the effect of lithium carbonate plus 131I in the treatment of Graves hyperthyroidism. Methods One hundred patients with Graves hyperthyroidism were enrolled in this study. All of them were randomly divided in to 2 groups： group I with 50 patients treated with 13q and group II with 50 patients treated with lithium carbonate plus 131I. Patients in group II were treated with a dose of 0.5 g per day （2×0.25 g） of lithium carbonate for 15 days before and after the administration of 13q. Thyroid weight was estimated by uhrasonography and careful palpation of the thyroid before treatment, and no significance were found between this two groups. Radiation absorbed dose rate in the front of neck was measured respectively 15, 30 and 45 d after the administration of 131I. Serum concentrations of TSH, free triiodothyrosine （iT3） and free thyroxine （iT4） were tested respectively before and 30, 45, 90, 180 days after administration of 131I. Results The radiation absorbed dose rate in the front of neck were decreased gradually as time went on after 131I therapy in each group. In general, the difference of radiation absorbed dose rate among different monitor term were significant （H=132.46, and 132.47, all P〈0.01 ）in same group. The difference of radiation absorbed dose rate between each other at 15, 30 and 45 d were significant （t=88.51,113.7, 59.42 in group I , and 83.44, 112.76, 70.18 in group II, all P〈0.01 ）, all of which in same monitor term were significantly higher in group II than those in group I （t=8.81, 15.18, 10.10, all P〈 0.01 ）. The mean serum TSH of each group before and all different time periods after treatment were below the normal range （0.55-4.78 mlU/L） without significant difference （F=1.23, P〉0.05）. In general, the differences of fT3 and fT4 values in all groups were significant （Fn3=9.65, Ffr4=22.45, all P〈0.01 ）before and after treatment. The ITs and iT4 values in both groups rose significantly 30 days after therapy （tfT3=5.23, tfT4= 10.14 in group I , tfT3=5.12, tfT4=9.98 in group II , all P〈0.01）, then decreased gradually to the normal ranges. The iT3 and fF4 values in group II were much lower than those in group I （tfT3=8.22, tfT4=19.18, all P〈0.01 ）30 days after therapy, no significance were found in other time periods. Cure rate of hyperthy- roidism was achieved in 36 of the 50 patients （72%） in group I and in 38 of the 50 patients （76%） in group II without significant difference. There were no significant differences in curative effect of the two groups （X2=0.21, P〉0.05 ）. Conclusion For patients withdrawing of ATD and those with short effective half-time, as well as those intolerant or invalid, the short term addition of lithium to 131I allows for a better control of thyrotoxia and the completeness of treatment. But there have not been observed that lithium carbonate plus 131I can improve the long term cure rate of Graves hyperthyroidism. Key words: Graves disease;  Iodine radioisotopes;  Lithium carbonate;  Chemotherapy, adjuvant