Long-term results of two schedules of radioiodine treatment for toxic multinodular goitre

Abstract

The long-term effects of two schedules of radioiodine therapy in patients with toxic multinodular goitre were evaluated. Forty-five patients (group A) were treated with low doses and 58 patients (group B) with calculated doses adjusted for thyroid weight (1.85-3.70 MBq/g) and radioactive iodine uptake. Follow-up (mean +/- SEM) was 4.3 +/- 0.2 years and 5.2 +/- 0.3 years, respectively (P > 0.1). At the end of follow-up, hyperthyroidism was successfully reversed in 73% (group A) and 88% (group B). In each group, hypothyroidism was present in 7%. The total dose per gram of thyroid tissue was not significantly different in groups A and B (2.1 +/- 0.2 vs 2.7 +/- 0.2 MBq/g). However, for patients treated with calculated doses the number of 131I administrations was significantly lower (1.3 +/- 0.1) than for patients treated with low doses (2.2 +/- 0.2), and the percentage of patients who were adequately treated with a single dose was more than twice as high (66% in group B versus 27% in group A). Euthyroidism was reached within a significantly shorter time after treatment with calculated doses (median time 0.6 years in group B vs 1.5 years in group A; life table analysis). It is concluded that radioiodine is an effective treatment for toxic multinodular goitre with a low risk of post-treatment hypothyroidism and that calculated (higher) doses appear to be preferable to low doses.

Therapy of large multinodular goitre using repeated doses of radioiodine

“…The results of LMG volume reduction obtained using our regimen of four fractions of RIT 800 MBq each administered every 3 months are comparable with the results described in the literature [36]. Despite some controversies, RIT can be regarded as a routine treatment option in inoperable cases.…”

Comparison of four different protocols of I-131 therapy for treating single toxic thyroid nodule

“…Methimazole is discontinued at least 48 h before measurement of RAIU and radioiodine therapy. We previously showed that methimazole discontinuation for longer than 48-72 h will not increase thyroid uptake [9]. Exclusion criteria were multinodular goiter, double adenoma, and radioactive thyroid uptake of less than 25% (Table 1).…”

“…However, there is no consensus on the administered dose of radioiodine per gram of thyroid weight too [7,8]. Some investigators prefer to administer a low dose of about 1.85 MBq/g of thyroid weight whereas others apply high doses up to even 7.4 MBq/g [9,10]. The aim of this study was to compare the results of treatment with different doses and find the optimal dose for treatment of these patients.…”

Efficacy of Different Protocols of Radioiodine Therapy for Treatment of Toxic Nodular Goiter: Systematic Review and Meta-Analysis of the Literature

“…Cure of hyperthyroidism was defined as hypothyroidism or euthyroidism one year after therapy. Studies with calculated dosimetry method evaluated thyroid volume by palpation (5), ultrasonography (4, 16) or thyroid radioisotope scanning (13, 14). Appraisal of the articles (Table 2) was done using Oxford University table for critical appraisal for therapy studies (http://www.cebm.net/index.aspx?o= 1097 Accessed Nov 2012), separately, by two physicians.…”