Radioiodine (131I) administration has been found to be effective in the treatment of hyperfunctioning and normofunctioning multinodular goiter. Moreover, lithium therapy has been shown to enhance the radioiodine efficacy and to reduce the transient thyrotoxicosis induced by radioiodine.
Aim of the present study was to evaluate the long term efficacy of 131I with or without lithium administration in the treatment of non toxic multinodular goiter (NTMG). Eighty patients without thyroid auto-antibodies were randomized into two groups: # 1, treated with con I131+ lithium (900 mg/die for 6 days) and # 2, treated with 131I alone. The 131I activity (MBq) was calculated according to thyroid volume (TV) (222600 MBq, with a mean dose/patient of 555 MBq). Ultrasonography and biochemical analyses were evaluated before and 1, 3, 6, 12 and 24 months after 131I. A mean thyroid volume reduction of 49% was observed at two years of follow-up without significant differences between the two groups. Forty-five patients were re-evaluated after a longer follow-up (4170 months). Thyroid volume further decreased (mean reduction: 50.7%) in 61% of these patients, and remained unmodified in the remaining cases, without significant differences between the two groups. A permanent hypothyroidism was diagnosed in 21.4% of patients during the first two years of follow-up, without differences between the 2 groups; no additional patients developed hypothyroidism in the following 3 years of follow-up.
In conclusion, present data confirm the efficacy of 131I in the treatment of non toxic goiter. The maximum thyroid volume reduction was achieved 2 years after the therapeutic administration and no relapse was observed in the following years. Permanent hypothyroidism developed in about 20% of cases during the first 2 years of follow-up. The association with lithium treatment neither enhanced the efficacy to 131I treatment nor influenced the development of permanent hypothyroidism.
03 - 07 May 2008
European Society of Endocrinology