title: 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.
authors.affiliation: Department of Nuclear Medicine, University Hospital Nijmegen St. Radboud, The Netherlands.
authors.forename: D A
authors.initials: DA
authors.lastname: Huysmans
authors.forename: A R
authors.initials: AR
authors.lastname: Hermus
authors.forename: F H
authors.initials: FH
authors.lastname: Corstens
authors.forename: P W
authors.initials: PW
authors.lastname: Kloppenborg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006044:Goiter, Nodular / Q000532:radiotherapy*; D006111:Graves Disease / Q000532:radiotherapy*; D006801:Humans; D007037:Hypothyroidism / Q000453:epidemiology; D015994:Incidence; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D011879:Radiotherapy Dosage; D013997:Time Factors
chemical_list: D007457:Iodine Radioisotopes