Development of high-resolution YAP(Ce) x-ray camera for the imaging of astatine-211(At-211) in small animals

Kouhei Nakanishi, Seiichi Yamamoto, Tadashi Watabe, Kazuko Kaneda-Nakashima, Yoshifumi Shirakami, Kazuhiro Ooe, Atsushi Toyoshima, Atsushi Shinohara, Takahiro Teramoto, Jun Hatazawa, Kei Kamada, Akira Yoshikawa

Research output: Contribution to journalArticlepeer-review

Abstract

Purpose: Astatine-211 (At-211) is a promising alpha emitter for radionuclide therapy. High-resolution in vivo imaging of At-211 in small animals is needed for the development of At-211 radiopharmaceuticals. For this purpose, we developed a low-energy x-ray camera using a thin YAlO3:Ce (YAP(Ce)) plate to image the low-energy x rays (73–87 keV) from the daughter radionuclide of At-211 (Po-211). Method: We optically coupled a 38 × 38 × 1-mm YAP (Ce) plate to a position-sensitive photomultiplier (PSPMT) to develop an imaging detector. A pinhole or a parallel hole collimator was attached to the imaging detector, and the performance was measured for 60-keV gamma photons. With the developed x-ray camera, we carried out imaging of a mouse that had been administered At-211-NaAt. Results: The intrinsic spatial resolution of the YAP (Ce) x-ray camera was approximately 1.2 mm FWHM, and the energy resolution was 22% FWHM. With a 5-mm-thick parallel hole collimator, the spatial resolution was 3.8 mm FWHM with a sensitivity of 8 × 10−4 at 10 mm, which is a typical distance from the surface of the collimator to a subject in mouse imaging. Using a 1-mm diameter pinhole collimator, the spatial resolution was 1.8 mm FWHM with a sensitivity of 3.5 × 10−4 at 10 mm from the collimator. In the mouse images measured by the developed x-ray camera, we could clearly observe that the At-211 accumulated in the thyroid gland and the stomach of the mouse. Conclusion: We concluded that the YAP (Ce) x-ray camera is useful for in vivo imaging of At-211.

Original languageEnglish
Pages (from-to)5739-5748
Number of pages10
JournalMedical Physics
Volume47
Issue number11
DOIs
Publication statusPublished - 2020 Nov

Keywords

  • 211At
  • YAP(Ce)
  • characteristic x rays
  • imaging
  • in vivo imaging

ASJC Scopus subject areas

  • Biophysics
  • Radiology Nuclear Medicine and imaging

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