Optimized radioiodine therapy for Graves?? disease: Two MIRD-based models for the computation of patient-specific therapeutic 131I activity

Abstract

The formalism developed appears to be a good compromise between all the common formalisms already used in many institutions. Furthermore, it allows the exposures of target volumes and non-target volumes to be planned individually and practical individual radiation protection recommendations to be implemented.

A simple and accurate dosimetry protocol to estimate activity for hyperthyroidism treatment

“…in France, in Germany, in Italy). Hyperthyroidism Original must be eradicated by employing an individualized activity and the lowest dose [8][9][10][11]; this was the cornerstone on which was based this work. Several issues are addressed in this paper: first, the compromise between treatment efficacy and reduction of doses to the blood pool/bone marrow (in Graves' disease patients) or to the normal tissues of the thyroid (in ATN patients) is intensely debated in the scientific community [14,16,33].…”

“…where is patients' thyroid uptake at time t, normalized for capsule uptake at time 0; U, a and b were estimated with reference to the function fit and represents radioiodine transfer rate (a: elimination from thyroid; b: elimination from blood; U • a: thyroid uptake). We chose this function taking into account 131 I alleged bi-compartmental kinetics (thyroid and blood pool) in benign thyroid diseases [10,11,27,31]. In all cases the fit was optimal, R 2 was higher than 0.90.…”

“…Of the three approaches considered in this study, the EANM algorithm appears to provide the best dose estimation, since it yields very small differences (3%) compared to OLINDA/EXM. For both methods (EANM and OLINDA/EXM), residence time estimation was mandatory and the bi-compartmental model was considered adequate for a correct determination of residence time [10,11,31]. Taking these results in due consideration, our routine practice is mostly oriented towards the EANM algorithm.…”

“…Other authors recommend, instead, using a patient-specific dosimetric method based on calculated activities [3]. This is also the approach set forth in institutional guidelines, such as the Euratom Directive 43/97 [7], the ICRU (International Commission on Radiological Units and Measurements) Report 67 [8], as well as in the French, German and Italian legislations [9][10][11]. Furthermore, several papers have reported a dose-related outcome of radioiodine treatment [1,12,13].…”

Investigation of post-therapeutic image-based thyroid dosimetry using quantitative SPECT/CT, iodine biokinetics, and the MIRD’s voxel S values in Graves’ disease

“…The therapeutic effect of radioiodine therapy for Graves' disease relates to the amount of administered radioactivity, or thyroid-absorbed dose [4,5]. Several methods for calculating absorbed dose [6][7][8] include Marinelli et al's [8] or the European Association of Nuclear Medicine (EANM) guideline's methods [9,10]. Using the EANM guidelines, absorbed dose is determined based on thyroid volume, radioiodine uptake (RIU), and effective iodine half-life.…”