Impact of equipment technology on reference levels in fluoroscopy-guided gastrointestinal procedures.

OBJECTIVES: To evaluate the effect of equipment technology on reference point air kerma (Ka,r ), air kerma-area product (PKA ), and fluoroscopic time for fluoroscopically-guided gastrointestinal endoscopic procedures and establish benchmark levels.

METHODS: This retrospective study included the consecutive patients who underwent fluoroscopically-guided gastrointestinal endoscopic procedures from May 2016 to August 2023 at a tertiary care hospital in the U.S. Fluoroscopic systems included (a) Omega CS-50 e-View, (b) GE Precision 500D, and (c) Siemens Cios Alpha. Radiation dose was analyzed for four procedure types of endoscopic retrograde biliary, pancreas, biliary and pancreas combined, and other guidance. Median and 75th percentile values were computed using software package R (version 4.0.5, R Foundation).

RESULTS: This large study analyzed 9,459 gastrointestinal endoscopic procedures. Among four procedure types, median Ka,r was 108.8-433.2 mGy (a), 70-272 mGy (b), and 22-55.1 mGy (c). Median PKA was 20.9-49.5 Gy∙cm2 (a), 13.4-39.7 Gy∙cm2 (b), and 8.91-20.9 Gy∙cm2 (c). Median fluoroscopic time was 2.8-8.1 min (a), 3.6-9.2 min (b), and 2.9-9.4 min (c). Their median value ratio (a:b:c) was 8.5:4.8:1 (Ka,r ), 2.7:2.1:1 (PKA ), and 1.0:1.1:1 (fluoroscopic time). Median value and 75th percentile are presented for Ka,r , PKA , and fluoroscopic time for each procedure type, which can function as benchmark for comparison for dose optimization studies.

CONCLUSION: This study shows manifold variation in doses (Ka,r and PKA ) among three fluoroscopic equipment types and provides local reference levels (50th and 75th percentiles) for four gastrointestinal endoscopic procedure types. Besides procedure type, imaging technology should be considered for establishing diagnostic reference level.

SUMMARY: With manifold (2 to 12 times) variation in doses observed in this study among 3 machines, we recommend development of technology-based diagnostic reference levels for gastrointestinal endoscopic procedures.