Dataset Information

Human dosimetry of free ²¹¹At and meta-[²¹¹At]astatobenzylguanidine (²¹¹At-MABG) estimated using preclinical biodistribution from normal mice.

ABSTRACT:

Background

²¹¹At is one of the ideal nuclides for targeted radionuclide therapies (TRTs). Meta-[²¹¹At]astatobenzylguanidine (²¹¹At-MABG) has been proposed for the treatment of pheochromocytoma. To effectively use these radiopharmaceuticals, dosimetry must be performed. It is important to determine the absorbed doses of free ²¹¹At and ²¹¹At-MABG to determine the organs that may be at risk when using TRTs. The aim of this study was to estimate human dosimetry from preclinical biodistribution of free ²¹¹At and ²¹¹At-MABG in various organs in normal mice.

Methods

Male C57BL/6?N mice were administered 0.13?MBq of free ²¹¹At or 0.20?MBq of ²¹¹At-MABG by tail-vein injection. The mice were sacrificed at 5?min, and at 1, 3, 6, and 24?h after the injection (n?=?5 for each group). The percentage of injected activity per mass in organs and blood (%IA/g) was determined. The human absorbed doses of free ²¹¹At and ²¹¹At-MABG were calculated using the Organ Level INternal Dose Assessment/EXponential Modeling (OLINDA/EXM) version 2.0 and IDAC-Dose 2.1.

Results

High uptake of free ²¹¹At was observed in the lungs, spleen, salivary glands, stomach, and thyroid. The absorbed doses of free ²¹¹At in the thyroid and several tissues were higher than those of ²¹¹At-MABG. The absorbed doses of ²¹¹At-MABG in the adrenal glands, heart wall, and liver were higher than those of free ²¹¹At.

Conclusions

The absorbed doses of ²¹¹At-MABG in organs expressing the norepinephrine transporter were higher than those of free ²¹¹At. In addition, the biodistribution of free ²¹¹At was different from that of ²¹¹At-MABG. The absorbed dose of free ²¹¹At may help predict the organs potentially at risk during TRTs using ²¹¹At-MABG due to deastatination.

SUBMITTER: Ukon N

PROVIDER: S-EPMC7509022 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

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Publications

Human dosimetry of free 211At and meta-[211At]astatobenzylguanidine (211At-MABG) estimated using preclinical biodistribution from normal mice.

Ukon Naoyuki N Zhao Songji S Washiyama Kohshin K Oriuchi Noboru N Tan Chengbo C Shimoyama Saki S Aoki Miho M Kubo Hitoshi H Takahashi Kazuhiro K Ito Hiroshi H

EJNMMI physics 20200922 1

<h4>Background</h4>211At is one of the ideal nuclides for targeted radionuclide therapies (TRTs). Meta-[211At]astatobenzylguanidine (211At-MABG) has been proposed for the treatment of pheochromocytoma. To effectively use these radiopharmaceuticals, dosimetry must be performed. It is important to determine the absorbed doses of free 211At and 211At-MABG to determine the organs that may be at risk when using TRTs. The aim of this study was to ...[more]

PMID: 32960387

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