OBJECTIVE: The long-term effects of (131)I-therapy in patients with symptomatic non-toxic diffuse goitre were evaluated. DESIGN AND METHODS: In a prospective open study, 34 patients (median age: 40 yrs, range: 27-68 yrs) were enrolled who suffered from a non-toxic goitre absent of nodules on clinical examination and on ultrasonography. Treatment indication was the presence of goitre giving rise to cervical compression and/or cosmetic discomfort. The median (131)I activity was 600 MBq (200-600 MBq) administered orally on an outpatient basis. The patients were investigated by clinical examination, thyroid ultrasonography and thyroid function tests at regular intervals and for at least 12 months after the (131)I-therapy. Yearly follow-up continued until the end of the study period or if permanent hypothyroidism ensued. The severity of symptoms was evaluated by a Visual Analogue Scale (VAS) (range: 0-10). RESULTS: The median follow-up time was 36 months (12-84). Goitre volume was reduced from 67.9+/-28.5 ml to 43.4+/-18.7 ml (mean+/-S.D.) (P<0.001) 3 months after the (131)I-therapy. After 3 years of follow-up, only 28.1+/-2.0% (mean+/-S.E.) remained of the initial goitre mass (P<0.001). Goitre was no longer present in 76% of the patients at the end of follow-up. An inverse correlation was found 1 year after therapy, but not after 3 years, between the initial goitre size and the percent reduction (r=-0.44, P=0.01). Thirty-six percent had become hypothyroid after three years. Median VAS scores were reduced from an initial 7.0 (cervical compression) and 5.5 (cosmetic discomfort) to 0.0 at the end of follow-up (P<0.001). CONCLUSION: Our data justify treatment of non-toxic diffuse goitre with (131)I because goitre reduction is pronounced, along with a very high degree of patient satisfaction and few side effects. We suggest that (131)I-therapy can be used as an alternative to L-T(4) suppressive therapy and thyroidectomy in this group of patients.
SJ Bonnema, VE Nielsen and L Hegedus
SJ Bonnema, L Bartalena, AD Toft and L Hegedus
In routine use for more than 50 years, radioiodine ((131)I) is generally considered safe and devoid of major side effects. Therefore, it is surprising that relatively many aspects of radioiodine therapy are controversial, as illustrated by recent international questionnaire studies. Our review aims at highlighting three of these areas - namely, the influence of (131)I on the course of Graves' ophthalmopathy, the possible radioprotective effects of antithyroid drugs, and the use of (131)I in large goitres. (131)I therapy carries a small (but definite) risk of causing progression of Graves' ophthalmopathy. Identification of risk factors (thyroid dysfunction, high level of thyroid-stimulating hormone (TSH) receptor antibodies, cigarette smoking) allows the identification of patients at risk and the institution of concomitant glucocorticoid treatment, thereby hindering progression of eye disease. On the basis, largely, of retrospective data, it appears that carbimazole (or methimazole), if stopped 3-5 days before treatment, does not influence the outcome of (131)I therapy. Simultaneous thyrostatic medication most probably reduces the efficacy of (131)I, as does restarting it within 7 days. Propylthiouracil seems to have a more prolonged radioprotective effect than carbimazole. Surgery is the treatment of first choice in patients with a large goitre. However, in the case of patient ineligibility or preference, (131)I therapy may be an option. The treatment has a favourable effect on tracheal compression and inspiratory capacity, but the reduction in thyroid volume is only 30-40%. Inpatient treatment, necessitated by the large doses, makes the treatment cumbersome. Controversy related to radioiodine therapy is mainly based on the lack of adequate prospective randomised studies comparing efficacy, side effects, cost and patient satisfaction.
SJ Bonnema, FN Bennedbaek, J Gram, A Veje, J Marving and L Hegedus
OBJECTIVE: Retrospective studies have indicated that anti-thyroid drugs (ATD) might possess a radioprotective effect, leading to a higher rate of recurrence of hyperthyroidism after iodine-131 ((131)I) therapy. DESIGN: A randomized clinical trial was performed to clarify whether resumption of methimazole after (131)I influences the final outcome of this treatment. METHODS: We assigned 149 patients with Graves' disease or a toxic nodular goitre to groups either to resume (+ATD) or not to resume (-ATD) methimazole 7 days after (131)I. Before (131)I therapy, all patients were rendered euthyroid by methimazole, which was discontinued 4 days before the (131)I therapy. RESULTS: During the follow-up period of 12 Months, 13 patients developed hypothyroidism, 42 were euthyroid, and 18 had recurrence of hyperthyroidism in the +ATD group; the respective numbers in the -ATD group were 16, 42 and 18 (P=0.88). At 3 weeks after (131)I therapy, the serum free-thyroxine index was slightly decreased (by 5.7%; 95% confidence interval (CI) -15.5 to 5.4%) in the +ATD group, in contrast to an increase of 35.9% (95% CI 18.8 to 55.5%) in the -ATD group (P<0.001 between groups). In the subgroup that remained euthyroid during follow-up, thyroid Volume reduction, assessed by ultrasonography, was smaller in the +ATD group [38.7% (95% CI 33.3 to 44.1%)] than in the -ATD group [48.6% (95% CI: 41.5-55.6%)] (P<0.05). CONCLUSION: No radioprotective effect could be demonstrated, with regard to final thyroid function, for the resumpton of methimazole 7 days after (131)I therapy. Although resumption of methimazole slightly reduced the magnitude of shrinkage of the goitre obtained by (131)I, the prevention of a temporary thyrotoxicosis in the early period after radiation favours this regimen.