title: ¹³¹I treatment of toxic nodular goiter under combined thyrostatic-thyromimetic medication is at low risk of late hypothyroidism.
abstract: OBJECTIVE
  Treatment of toxic nodular goiter with ¹³¹I is a first-line therapy for hyperthyroidism. To avoid a thyrotoxic storm, ¹³¹I is usually administered after pretreatment with antithyroid drugs, with thyroid-stimulating hormone (TSH) increase and functional recruitment of inhibited normal tissue. Therefore, both autonomous nodule(s) and normal tissue are irradiated. This may be a reason for late hypothyroidism occurring in 15-25% of patients. This study aimed at assessing different pretreatment modalities with combined methymazole and triiodothyronine, achieving euthyroidism with suppressed TSH.
  
  
  METHODS
  After diagnosis of autonomously functioning toxic nodule, patients were subjected to thyrostatic medication. Two months later, TSH was checked; if >0.5 mU/L triiodothyronine treatment was associated. After 2 more months, if the TSH level was suppressed, patients received ¹³¹I-therapy. A total of 149 patients were consecutively enrolled, 41 of whom with uninodular and 108 with multinodular goiter. They were evaluated at diagnosis, pretreatment, 3 and 6 months after therapy and at late follow-up (6.8+/-4.2 years; range: 1-22 years).
  
  
  RESULTS
  Administered activity was calculated according to ¹³¹I uptake and gland weight. Methymazole was discontinued 6 days before treatment and T3 was maintained until administration of ¹³¹I-therapy. Euthyroidism was achieved in 88% of patients. At late follow-up, subclinical hypothyroidism was observed in 10 patients (6.7%) and overt hypothyroidism in 5 patients (3.3%). No pathological consequences or side effects of ¹³¹I-therapy were found during the 6.8+/-4.2 year follow-up period.
  
  
  CONCLUSIONS
  Treatment of toxic nodular goiter with ¹³¹I-therapy, under combined thyrostatic-thyromimetic treatment is a simple, safe, well-tolerated, and effective procedure.
authors.affiliation: Unit of Nuclear Medicine, Civilian Hospitals of Brescia, Brescia, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Paghera
authors.forename: M B
authors.initials: MB
authors.lastname: Panarotto
authors.forename: G
authors.initials: G
authors.lastname: Maira
authors.forename: G C
authors.initials: GC
authors.lastname: Magri
authors.forename: F
authors.initials: F
authors.lastname: Bertagna
authors.forename: G
authors.initials: G
authors.lastname: Bosio
authors.forename: P
authors.initials: P
authors.lastname: Rossini
authors.forename: A
authors.initials: A
authors.lastname: De Agostini
authors.forename: G
authors.initials: G
authors.lastname: Savelli
authors.forename: S
authors.initials: S
authors.lastname: Lucchini
authors.forename: R
authors.initials: R
authors.lastname: Giubbini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D013956:Antithyroid Agents / Q000627:therapeutic use; D003131:Combined Modality Therapy; D005260:Female; D006044:Goiter, Nodular / Q000188:drug therapy* / Q000532:radiotherapy*; D006801:Humans; D007037:Hypothyroidism / Q000517:prevention & control; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008713:Methimazole / Q000627:therapeutic use; D008875:Middle Aged; D013971:Thyrotoxicosis / Q000188:drug therapy* / Q000532:radiotherapy*; D013997:Time Factors; D014284:Triiodothyronine / Q000627:therapeutic use
chemical_list: D013956:Antithyroid Agents; D007457:Iodine Radioisotopes; D014284:Triiodothyronine; D008713:Methimazole