title: A prospective randomized study of the efficacy and cost-effectiveness of high and low dose regimens of I-131 treatment in hyperthyroidism.
abstract: OBJECTIVE
  To compare the efficacy and cost-effectiveness of high and low dose regimens of I-131 treatment in patients with hyperthyroidism.
  
  
  METHODS
  One hundred fifty patients with proven hyperthyroidism were randomly allocated into the high (74 patients) and low (76 patients) dose regimen of I-131 treatment. Four patients of the high dose group and one patient of the low dose group were excluded because of lost follow-up. A gland-specific dosage was calculated on the estimated weight of thyroid gland and 24-hour I-131 uptake. The high and low I-131 dose regimens were 150 microCi/gm and 100 microCi/gm, respectively. The first mean radioiodine activity administered to the high and low dose group was 10.2 and 8 mCi, respectively. Repeated treatment was given to 25 patients of the high dose group and 40 patients of the low dose group. Clinical outcome and calculated costs for outpatient attendances, and laboratory tests together with initial and subsequent treatments were evaluated for one year after I-131 treatment. Elimination of hyperthyroidism that resulted in either euthyroidism or hypothyroidism was classified as therapeutic success. The cost effectiveness was also compared.
  
  
  RESULTS
  At 6 months after treatment, 45 (64.3%) patients receiving high dose and 59 (78.7%) patients receiving low dose were hyperthyroidism. Clinical outcome at one year showed persistence of hyperthyroidism in 21 (30%) patients of the high dose regimen and 36 (48%) patients of the low dose regimen. At one year post treatment, it was demonstrated that the high dose regimen could eliminate hyperthyroidism in a significantly shorter time than the low dose regimen, i.e., 259.6 days and 305.5 days, respectively, p = 0.008). For the persistent hyperthyroid patients, the average total cost of treatment in the low dose group was significantly higher than that of the high dose group, i.e., 13,422.78 baht and 10,942.79 baht, respectively; p = 0.050).
  
  
  CONCLUSIONS
  A high dose regimen of radioactive iodine treatment is more effective than the low dose regimen. The successful outcome of a high dose regimen occurred significantly earlier than that of the low dose regimen. For the persistent hyperthyroid patients, the average total cost in the low dose group was significantly higher than that of the high dose group.
authors.affiliation: Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkoknoi, Bangkok, Thailand. sipps@mahidol.ac.th
authors.forename: Pawana
authors.initials: P
authors.lastname: Pusuwan
authors.forename: Malulee
authors.initials: M
authors.lastname: Tuntawiroon
authors.forename: Nopamol
authors.initials: N
authors.lastname: Sritongkul
authors.forename: Pachee
authors.initials: P
authors.lastname: Chaudakshetrin
authors.forename: Cherdchai
authors.initials: C
authors.lastname: Nopmaneejumruslers
authors.forename: Chulalak
authors.initials: C
authors.lastname: Komoltri
authors.forename: Kullathorn
authors.initials: K
authors.lastname: Thepamongkhol
authors.forename: Benjapa
authors.initials: B
authors.lastname: Khiewvan
authors.forename: Pongpija
authors.initials: P
authors.lastname: Tuchinda
authors.forename: Sutin
authors.initials: S
authors.lastname: Sriussadaporn
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003362:Cost-Benefit Analysis; D004307:Dose-Response Relationship, Radiation; D016527:Drug Costs / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D017048:Health Care Costs; D006801:Humans; D006980:Hyperthyroidism / Q000532:radiotherapy*; D007457:Iodine Radioisotopes / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011878:Radiotherapy / Q000191:economics*; D011879:Radiotherapy Dosage; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes