title: Calculation of therapeutic activity of radioiodine in Graves' disease by means of Marinelli's formula, using technetium (99mTc) scintigraphy.
abstract: The therapeutic activity of131I administered to patients with Graves' disease can be calculated by means of Marinelli's formula. The thyroidal iodine uptake (131IUmax) needed for the calculation is usually determined with the use of131I. The purpose of the paper was to estimate131IUmaxon the basis of technetium uptake in the thyroid at 20 min (99mTcU20min). Eighty patients suffering from Graves' disease were qualified for radioiodine therapy with measurement of fT4, fT3, thyroid-stimulating hormone and its receptor (TRAb). Prior to the treatment, all the patients were euthyroid.131IUmaxfor each patient was determined according to the levels of131I after 24 h (131IU24h), while effective half-life (Teff) according to the measurements of131IU24hand131I uptake after 48 h (131IU48h). Additionally, on the day before measuring131IU24h,99mTcU20minwas calculated for each patient. It was demonstrated that there existed a correlation, with statistical significance at p < 0.05, between the following pairs of values: TRAb and131IU24h, TRAb and99mTcU20min, and99mTcU20minand131IU24h. The interdependence between131IU24hand99mTcU20minat the level of significance p < 0.05 is described by the following algorithms:131IU24h= 17.72 × ln (99mTcU20min) + 30.485, if TRAb < 10 IU/ml, and131IU24h= 18.03 × ln (99mTcU20min) + 38.726, if TRAb > 10 IU/ml. It is possible to predict thyroid iodine uptake131IU24hin Graves' disease on the basis of measuring the uptake of99mTcU20min. This shortens the time necessary for diagnosis and enables the calculation of131I activity using Marinelli's formula.
authors.affiliation: Department of Nuclear Medicine, Medical University of Bialystok, M. Skłodowskiej-Curie St. 24A, 15-276, Bialystok, Poland. piotrmjs@wp.pl.
authors.forename: Piotr
authors.initials: P
authors.lastname: Szumowski
authors.affiliation: Department of Nuclear Medicine, Medical University of Bialystok, M. Skłodowskiej-Curie St. 24A, 15-276, Bialystok, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Mojsak
authors.affiliation: Department of Nuclear Medicine, Medical University of Bialystok, M. Skłodowskiej-Curie St. 24A, 15-276, Bialystok, Poland.
authors.forename: Saeid
authors.initials: S
authors.lastname: Abdelrazek
authors.affiliation: Department of Nuclear Medicine, Medical University of Bialystok, M. Skłodowskiej-Curie St. 24A, 15-276, Bialystok, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Sykała
authors.affiliation: Department of Nuclear Medicine, Medical University of Bialystok, M. Skłodowskiej-Curie St. 24A, 15-276, Bialystok, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Amelian-Fiłonowicz
authors.affiliation: Department of Nuclear Medicine, Medical University of Bialystok, M. Skłodowskiej-Curie St. 24A, 15-276, Bialystok, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Jurgilewicz
authors.affiliation: Department of Nuclear Medicine, Medical University of Bialystok, M. Skłodowskiej-Curie St. 24A, 15-276, Bialystok, Poland.
authors.forename: Janusz
authors.initials: J
authors.lastname: Myśliwiec
mesh_terms: D000465:Algorithms; D005260:Female; D006111:Graves Disease / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics / Q000627:therapeutic use*; D008297:Male; D015609:Organotechnetium Compounds; D011877:Radionuclide Imaging
chemical_list: D007457:Iodine Radioisotopes; D015609:Organotechnetium Compounds
keywords: Graves’ disease; Marinelli’s formula; Thyroid iodine uptake; Thyroid technetium uptake