[Scintigraphic method in the quantification of morphological and functional changes of thyroid autonomy before and...

The regional excess of function and cell mass in potentially "toxic" thyroid areas with nonimmunogenic hyperthyroidism (NIH) (unifocal [UFA, previously "toxic adenoma"] and multifocal functional autonomies [MFA or "toxic goiter"]) are quantified by an enhanced diagnostic method: double isotope subtraction scintigraphy (Ssc) with radioiodine and 99mTc-MIBI. In 125 patients, a toxicity index T was derived from the Ssc (*J-*MIBI), and a cell density index Q from the *MIBI image. The median value of T, as an expression of the regional autonomous excess function (165 in UFA, 15 in MFA), by far exceeded the median value of Q (3.8 in UFA, 2.0 in MFA). The significant (p < 0.001) effects of radioiodine therapy (RIT) were monitored by the changes towards normalization of T and Q in 53 patients in follow-ups 3 and 9 months thereafter. Our aim was (a) to extend the conventional field of measurement of NIH-hyperthyroidism with the scintigraphically quantified function and morphology, and (b) to compare the return to euthyroid state with scintigraphic scarification of the functionally autonomous areas.