Diagnostic Reference Levels for Fluoroscopy-guided Gastrointestinal Procedures in Japan from the REX-GI Study: A Nationwide Multicentre Prospective Observational Study
Shiro Hayashi, Mamoru Takenaka, Makoto Hosono, Hirofumi Kogure, Kenkei Hasatani, Takahiro Suda, Hirotsugu Maruyama, Kazuhiro Matsunaga, Hideyuki Ihara, Toshiyuki Yoshio, Koji Nagaike, Takuya Yamada, Takayuki Yakushijin, Tadayuki Takagi, Hidetaka Tsumura, Akira Kurita, Satoshi Asai, Yukiko Ito, Toshio Kuwai, Yasuki Hori, Iruru Maetani, Kenji Ikezawa, Takuji Iwashita, Kengo Matsumoto, Toshio Fujisawa, Tsutomu Nishida
Abstract
BackgroundDiagnostic reference levels (DRLs) are required to optimize medical exposure. However, data on DRLs for interventional fluoroscopic procedures are lacking, especially in gastroenterology. This study aimed to prospectively collect currently used radiation doses and help establish national DRLs for fluoroscopy-guided gastrointestinal procedures in Japan.MethodsThis multicentre, prospective, observational study collected actual radiation dose data from endoscopic retrograde cholangiopancreatography (ERCP), interventional endoscopic ultrasound (EUS), balloon-assisted enteroscopy (BAE), enteral metallic stent placement, and enteral tube placement from May 2019 to December 2020. The study outcomes were fluoroscopy time (FT: min), air kerma at the patient entrance reference point (Ka,r: mGy), air kerma area product (PKA: Gycm2International Commission on Radiological Protection (ICRP)The 2007 recommendations of the International Commission on Radiological Protection. 103. ICRP Publication, 2007Google Scholar), and radiation dose rate (RDR: mGy/min). Additionally, the basic settings of fluoroscopy equipment and the factors related to each procedure were investigated. This study was registered in the UMIN Clinical Trial Registry (UMIN 000036525).FindingsOverall, 12959 fluoroscopy-guided gastrointestinal procedures were included from 23 hospitals in Japan. For 11162 ERCPs, the median/third quartile values of Ka,r (mGy), PKA (Gycm2International Commission on Radiological Protection (ICRP)The 2007 recommendations of the International Commission on Radiological Protection. 103. ICRP Publication, 2007Google Scholar), and FT (min) were 69/145 mGy, 16/32 Gycm2International Commission on Radiological Protection (ICRP)The 2007 recommendations of the International Commission on Radiological Protection. 103. ICRP Publication, 2007Google Scholar, and 11/20 min, respectively. Similarly, these values were 106/219 mGy, 23/41 Gycm2International Commission on Radiological Protection (ICRP)The 2007 recommendations of the International Commission on Radiological Protection. 103. ICRP Publication, 2007Google Scholar and 17/27 min for 374 interventional EUSs; 53/104 mGy, 16/32 Gycm2International Commission on Radiological Protection (ICRP)The 2007 recommendations of the International Commission on Radiological Protection. 103. ICRP Publication, 2007Google Scholar and 10/15 min for 523 metallic stents; 56/104 mGy, 28/47 Gycm2International Commission on Radiological Protection (ICRP)The 2007 recommendations of the International Commission on Radiological Protection. 103. ICRP Publication, 2007Google Scholar, and 12/18 min for 599 tube placements; and 35/81 mGy, 16/43 Gycm2International Commission on Radiological Protection (ICRP)The 2007 recommendations of the International Commission on Radiological Protection. 103. ICRP Publication, 2007Google Scholar and 7/15 min for 301 BAEs, respectively. For the overall radiation dose rate, the median/third quartile values of RDR were 5.9/9.4 (mGy/min). The RDR values at each institution varied widely.InterpretationThis study reports the current radiation doses of fluoroscopy-guided gastrointestinal procedures expressed as DRL quantities. This will serve as a valuable reference for national DRL values.FundingThis work was supported by a clinical research grant from the Japanese Society of Gastroenterology.