Comparison of the dosimetry of scandium-43 and scandium-44 patient organ doses in relation to commonly used gallium-68 for imaging neuroendocrine tumours.

Détails

ID Serval
serval:BIB_4A9BBBA5A800
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Comparison of the dosimetry of scandium-43 and scandium-44 patient organ doses in relation to commonly used gallium-68 for imaging neuroendocrine tumours.
Périodique
EJNMMI physics
Auteur⸱e⸱s
Gomes C.V., Mendes B.M., Paixão L., Gnesin S., Müller C., van der Meulen N.P., Strobel K., Fonseca TCF, Lima TVM
ISSN
2197-7364 (Print)
ISSN-L
2197-7364
Statut éditorial
Publié
Date de publication
15/07/2024
Peer-reviewed
Oui
Volume
11
Numéro
1
Pages
61
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: epublish
Résumé
Several research groups have explored the potential of scandium radionuclides for theragnostic applications due to their longer half-lives and equal or similar coordination chemistry between their diagnostic and therapeutic counterparts, as well as lutetium-177 and terbium-161, respectively. Unlike the gallium-68/lutetium-177 pair, which may show different in-vivo uptake patterns, the use of scandium radioisotopes promises consistent behaviour between diagnostic and therapeutic radiopeptides. An advantage of scandium's longer half-life over gallium-68 is the ability to study radiopeptide uptake over extended periods and its suitability for centralized production and distribution. However, concerns arise from scandium-44's decay characteristics and scandium-43's high production costs. This study aimed to evaluate the dosimetric implications of using scandium radioisotopes with somatostatin analogues against gallium-68 for PET imaging of neuroendocrine tumours.
Absorbed dose per injected activity (AD/IA) from the generated time-integrated activity curve (TIAC) were estimated using the radiopeptides [ <sup>43/44/44m</sup> Sc]Sc- and [ <sup>68</sup> Ga]Ga-DOTATATE. The kidneys, liver, spleen, and red bone marrow (RBM) were selected for dose estimation studies. The EGSnrc and MCNP6.1 Monte Carlo (MC) codes were used with female (AF) and male (AM) ICRP phantoms. The results were compared to Olinda/EXM software, and the effective dose concentrations assessed, varying composition between the scandium radioisotopes.
Our findings showed good agreement between the MC codes, with - 3 ± 8% mean difference. Kidneys, liver, and spleen showed differences between the MC codes (min and max) in a range of - 4% to 8%. This was observed for both phantoms for all radiopeptides used in the study. Compared to Olinda/EXM the largest observed difference was for the RBM, of 21% for the AF and 16% for the AM for scandium- and gallium-based radiopeptides. Despite the differences, our findings showed a higher absorbed dose on [ <sup>43/44</sup> Sc]Sc-DOTATATE compared to its <sup>68</sup> Ga-based counterpart.
This study found that [ <sup>43/44</sup> Sc]Sc-DOTATATE delivers a higher absorbed dose to organs at risk compared to [ <sup>68</sup> Ga]Ga-DOTATATE, assuming equal distribution. This is due to the longer half-life of scandium radioisotopes compared to gallium-68. However, calculated doses are within acceptable ranges, making scandium radioisotopes a feasible replacement for gallium-68 in PET imaging, potentially offering enhanced diagnostic potential with later timepoint imaging.
Mots-clé
Dosimetry, Monte Carlo, Neuroendocrine tumours, Pet, Radiopeptides, Scandium, PET
Pubmed
Web of science
Open Access
Oui
Création de la notice
19/07/2024 11:25
Dernière modification de la notice
20/08/2024 7:22
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