Abe Koichiro, Baba Shingo, Etani Reo, Fujimto Takahiro, Hosono Makoto, Iimori Takashi, Inaki Anri, Ishiguro Masanobu, Miyaji Noriaki, Okizaki Atsutaka, Sasaki Takeshi, Tsushima Hiroyuki, Watanabe Hiroshi, Watanabe Masanori, Yada Nobuhiro
Department of Radiology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-Ku, Tokyo, 160-0023, Japan.
Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka, 812-8582, Japan.
Ann Nucl Med. 2025 Sep 3. doi: 10.1007/s12149-025-02102-y.
Diagnostic reference levels (DRLs) are practical benchmarks for optimizing patient radiation exposure in medical imaging. In Japan, national DRLs, including those for nuclear medicine together and other radiological procedures, were first established in 2015 and revised in 2020. In this study, we revised the DRL values of nuclear medicine for the establishment of DRLs2025, based on data collected from institutions nationwide throughout Japan. Data were collected via an online survey from facilities performing nuclear medicine procedures, including SPECT, PET, and hybrid CT imaging. Information on dose activity of the administered radiopharmaceuticals and CT parameters (CTDIvol and DLP) were collected. DRL values were determined through analysis of the submitted data, supplemented by panel discussions among experts taking into account the clinical appropriateness of the values and various technological factors. Overall, the newly established DRLs2025 demonstrated a decreasing trend in administered radiopharmaceutical activities, CTDIvol, and DLP compared with the previous surveys. This trend reflects ongoing efforts toward the optimization of radiation exposure and radiopharmaceutical dose reduction, likely driven by the introduction of image reconstruction methods based on newer technologies. However, substantial interfacility variations were observed, particularly in the CT parameters, suggesting disparities in equipment, imaging protocols, and the balance between image quality and radiation dose. The establishment of DRLs2025 underscores continued progress in optimizing radiation exposure in nuclear medicine practice in Japan. Although issues regarding data variability and quality remain, DRLs continue to be a key tool in radiation protection and quality assurance. Ongoing efforts to improve data collection systems and to align procedures with international standards are essential for the future refinement of DRLs.
诊断参考水平（DRLs）是优化医学成像中患者辐射剂量的实用基准。在日本，包括核医学及其他放射学检查的全国性DRLs于2015年首次制定，并于2020年进行了修订。在本研究中，我们基于从日本全国各机构收集的数据，对核医学的DRL值进行了修订，以建立2025年DRLs。数据通过在线调查从开展核医学检查的机构收集，包括单光子发射计算机断层扫描（SPECT）、正电子发射断层扫描（PET）和混合CT成像。收集了所施用放射性药物的剂量活性信息以及CT参数（容积CT剂量指数[CTDIvol]和剂量长度乘积[DLP]）。通过对提交数据的分析确定DRL值，并辅以专家小组讨论，同时考虑到这些值的临床适用性和各种技术因素。总体而言，与之前的调查相比，新建立的2025年DRLs显示所施用放射性药物活性、CTDIvol和DLP呈下降趋势。这一趋势反映了在优化辐射剂量和降低放射性药物剂量方面持续做出的努力，这可能是由基于新技术的图像重建方法的引入所推动的。然而，观察到各机构之间存在较大差异，尤其是在CT参数方面，这表明在设备、成像方案以及图像质量与辐射剂量之间的平衡方面存在差异。2025年DRLs的建立凸显了日本在优化核医学实践中辐射剂量方面的持续进展。尽管数据变异性和质量方面的问题仍然存在，但DRLs仍然是辐射防护和质量保证的关键工具。持续努力改进数据收集系统并使程序与国际标准保持一致对于未来完善DRLs至关重要。
