title: Characteristic X-ray imaging for palliative therapy using strontium-89 chloride: understanding the mechanism of nuclear medicine imaging of strontium-89 chloride.
abstract: Strontium-89 (Sr-89) chloride is a targeted palliative therapy used for painful bone metastasis in which repeated doses can be administered, and its usefulness has been reported in the case of bone metastasis of various primary tumors. However, the effectiveness of the pain relief treatment is only described using a subjective index such as the visual analog scale, which lacks objectivity. Although various attempts at quantifying the effectiveness of Sr-89 chloride therapy have been reported using nuclear medicine imaging for energy peaks around 70-80 keV, the principle of Sr-89 chloride imaging has not been explained. In this study, the principle of nuclear medicine imaging for Sr-89 chloride was evaluated using a fundamental study. Additionally, the optimal collimator for acquiring Sr-89 chloride image data was evaluated. Based on the results, the principle of nuclear medicine imaging for Sr-89 chloride could be explained: the energy peaks were characteristic X-rays produced by interactions between gamma rays (514 keV) emitted from Sr-85, which is included during the manufacturing process of the Sr-89 chloride solution, and the lead collimator used in the imaging. The optimal collimator for generating characteristic X-rays efficiently was identified as a middle-to-high energy collimator.
authors.affiliation: Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan.|Office of Radiation Technology, Keio University Hospital, Tokyo, 160-0016, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Owaki
authors.affiliation: Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan. kzminoue@tmu.ac.jp.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Inoue
authors.affiliation: Department of Radiology, The Jikei University Hospital, Tokyo, 105-8471, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Narita
authors.affiliation: Department of Radiological Technology, Tsukuba International University, Tsukuba, Ibaraki, 300-0051, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Tsuda
authors.affiliation: Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Fukushi
mesh_terms: D015902:Gamma Cameras; D007091:Image Processing, Computer-Assisted; D009010:Monte Carlo Method; D009683:Nuclear Medicine; D010166:Palliative Care; D013324:Strontium; D013326:Strontium Radioisotopes; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*
chemical_list: D013326:Strontium Radioisotopes; C000615489:Strontium-89; C025700:strontium chloride; D013324:Strontium
keywords: Bremsstrahlung imaging; Characteristic X-ray imaging; Strontium-85; Strontium-89 chloride