title: Effect of 1110 MBq Radioiodine in Reducing Thyroid Volume in Multinodular Goiter: A New Protocol.
abstract: BACKGROUND
  There is no consensus on the optimal treatment of multinodular goiter (MNG), but in the past few years, the use of radioiodine has increased. This study's objective was to evaluate adjuvant methimazole (MMI) therapy to increase and standardize radioiodine uptake (RAIU) with a fixed therapeutic (131)I dose of 1110 MBq (30 mCi).
  
  
  METHODS
  Our study included 5 women with MNG treated with MMI, 10 - 15 mg/day for 2 to 4 months, prior to the administration of 1110 MBq (131)I (30 mCi); none of the patients developed hypothyroidism during MMI therapy and had average basal TSH levels of 0.32 ± 0.39 mIU/L that increased to 2.6 ± 0.9 mIU/L (P = 0.07).
  
  
  RESULTS
  RAIU increased from 25.6 ± 8.7% to 49.2 ± 8.3% (P = 0.003). All patients were followed for 12 months: median thyroid volume (TV) decreased from 77.2 mL (32.9 - 124.2) to 48.8 ml (12.4 - 68.9) with an average decrease of 46.4 ± 14.8% (P = 0.01). All patients developed hypothyroidism during the first 6 months after radioiodine therapy.
  
  
  CONCLUSIONS
  This new therapeutic protocol using MMI as adjuvant therapy is effective in increasing RAIU as well as the deleterious effects of (131)I, without increasing the required dose, but leading to thyroid volume decreases similar to those reported with the use of recombinant human thyrotropin (rhTSH) or higher radioiodine doses.
authors.affiliation: Department of Internal Medicine, Instituto Nacional de Ciencias Medicas y Nutricion "Salvador Zubira", DF, Mexico.
authors.forename: Armando
authors.initials: A
authors.lastname: Flores-Rebollar
authors.forename: Aida
authors.initials: A
authors.lastname: Ruiz-Juvera
authors.forename: Guadalupe
authors.initials: G
authors.lastname: Lopez-Carrasco
authors.forename: Ofelia
authors.initials: O
authors.lastname: Gonzalez-Trevino
keywords: 131I; Hyperthyroidism; Methimazole; Multinodular goiter; Radioiodine; Thyroid; Treatment; Uptake