title: Single dose planning for radioiodine-131 therapy of Graves' disease.
abstract: OBJECTIVE
  Patients with Graves' disease were studied one year after radioiodine-131 therapy to assess the relationship between the effectiveness of the therapy and the radioiodine doses used.
  
  
  METHODS
  Patients were classified into three groups according to thyroid function as hyperthyroidism, euthyroidism and hypothyroidism at one year after I-131 therapy. In these groups we compared the mean values of dose, dose per thyroid weight calculated with I-123 uptake before the therapy (pre D/W), dose per thyroid weight calculated with therapeutic I-131 uptake (post D/W), and absorbed dose.
  
  
  RESULTS
  No significant differences were found between the three groups in terms of dose or pre D/W. The mean values of post D/W and absorbed dose in the non-hyperthyroid (euthyroid and hypothyroid) group were significantly greater than those in the hyperthyroid group. Post D/W of 6.3 MBq/g was a threshold separating the non-hyperthyroid group from the hyperthyroid group. There was no correlation between pre D/W and post D/W; however, the mean post D/W was significantly greater than the mean pre D/W. All patients with pre D/W above 6.3 MBq/g showed non-hyperthyroidism at one year after the radioiodine treatment.
  
  
  CONCLUSIONS
  No indicators before the radioiodine therapy had significant relationships with the effectiveness of the therapy at one year after the treatment. However, the single therapy planned for setting the pre D/W above 6.3 MBq/g will certainly make the patients non-hyperthyroid. As this proposal of dose planning is based on a small number of patients, further study is needed.
authors.affiliation: Department of Biotracer Medicine, Kanazawa University Graduate School of Medical Sciences, Japan. happyman@nmd.m.kanazawa-u.ac.jp
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kita
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Yokoyama
authors.forename: Seigo
authors.initials: S
authors.lastname: Kinuya
authors.forename: Junichi
authors.initials: J
authors.lastname: Taki
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Michigishi
authors.forename: Norihisa
authors.initials: N
authors.lastname: Tonami
mesh_terms: D000328:Adult; D000368:Aged; D019583:Dose Fractionation, Radiation; D005260:Female; D006111:Graves Disease / Q000175:diagnosis* / Q000532:radiotherapy*; D006801:Humans; D007457:Iodine Radioisotopes / Q000008:administration & dosage*; D008297:Male; D011874:Radiometry / Q000379:methods*; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals