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Development of high‐resolution YAP(Ce) x‐ray camera for the imaging of astatine‐211(At‐211) in small animals
Author(s) -
Nakanishi Kouhei,
Yamamoto Seiichi,
Watabe Tadashi,
KanedaNakashima Kazuko,
Shirakami Yoshifumi,
Ooe Kazuhiro,
Toyoshima Atsushi,
Shinohara Atsushi,
Teramoto Takahiro,
Hatazawa Jun,
Kamada Kei,
Yoshikawa Akira
Publication year - 2020
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1002/mp.14455
Subject(s) - collimator , image resolution , full width at half maximum , optics , gamma camera , photomultiplier , resolution (logic) , physics , pinhole (optics) , pinhole camera , nuclear medicine , scintimammography , detector , materials science , medicine , mammography , artificial intelligence , computer science , cancer , breast cancer
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 YAlO 3 :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.