title: A simple and accurate dosimetry protocol to estimate activity for hyperthyroidism treatment.
abstract: BACKGROUND
  Aim of the study was to evaluate accuracy of different dosimetry protocols in estimating the required 131I activity to treat hyperthyroid patients.
  
  
  METHODS
  Forty consecutive patients were analysed: twenty-eight Graves' disease; twelve autonomous thyroid nodule (ATN). Maximum-uptake, effective half-time and residence-time were estimated from Radioiodine Uptake Test. Residence-time was estimated using a bi-compartmental model. For 131I activity calculation, algorithms laid down in European Association of Nuclear Medicine (EANM) guidelines, ICRP 53 approach and a mono-exponential formula (ME), were compared with OLINDA/EXM results.
  
  
  RESULTS
  Based on EANM guidelines, activities to be administered were 3% higher in Graves' disease (p = 0.001) and 3% higher in ATN (p = 0.046). Calculated activities using ICRP 53 approach were significantly lower compared to OLINDA/EXM: 33% in Graves' disease; 17% in ATN. Activities recommended by ME, were significantly higher: in Graves' disease 20%; 42% in ATN.
  
  
  CONCLUSIONS
  Only EANM algorithm predict quite well, compared to OLINDA/EXM, the required activity to treat hyperthyroid patients.
authors: Nuclear Medicine Unit, San Luigi Gonzaga Hospital, University of Turin, Orbassano, Italy; Medical Science Department, University A. Avogadro, Novara, Italy. askanjeti@yahoo.it.
authors: Andrea
authors: A
authors: Skanjeti
authors: Anna
authors: A
authors: Miranti
authors: Gabriela Mariam
authors: GM
authors: Delgado Yabar
authors: Davide
authors: D
authors: Bianciotto
authors: Edoardo
authors: E
authors: Trevisiol
authors: Michele
authors: M
authors: Stasi
authors: Valerio
authors: V
authors: Podio
mesh_terms: D005260:Female; D006111:Graves Disease / Q000532:radiotherapy*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D011874:Radiometry / Q000379:methods*; D016606:Thyroid Nodule / Q000532:radiotherapy*
chemical_list: D007457:Iodine Radioisotopes