Quebec-DRL-Project: Design and Validation for Effective Implementation
Abstract:
Rationale: The use of ionizing radiation provides undeniable benefits in medical imaging. However, the health risk linked to exposure to ionizing radiation increases with the level and frequency of exposure. With the number of com puted tomography (CT) scans performed in Quebec growing by 204% in the last decade, it is essential to ensure that CT protocols are optimized. The International Commission on Radiological Protection (ICRP) introduced the concept of diagnostic reference level (DRL) in 1996 with the aim of optimizing the protection of patients during their exposure to medical imaging. The International Atomic Energy Agency (IAEA) specified, in 2016, that it was required to ensure that DRLs were established for health institutions using ionizing radiation.
Objective: The final objective of this work is to establish DRLs for Quebec; this is the Quebec-DRL-Project (Q-DRL-P). The current study presents and validates the design of Q-DRL-P prior to its implementation for CT applications.
Methods: The Dossier santé Québec (DSQ) imaging directories collect medical imaging data from all radiology departments in Quebec. This communication platform allows to put into perspective transversal and longitudinal views of patient monitoring in radiology. The model proposed to establish and assume the continuous improvement of Q-DRL-P is a cyclical process main tained by three entities, which are all the radiology services, the DSQ and a processing unit. We review data availability and nomenclature to ensure the success of Q-DRL-P. Since the patient exposure level may vary depending on the characteristics of the imaging device, we introduced a technology-based CT scanner categorization model into our design to ensure consistency of DRL values.
Preliminary Data: For validation and illustration, we analyzed CT exposure data from non-contrast thorax exam inations across 11 CT rooms, involving 13,235 adult women and 12,709 adult men. The local diagnostic reference levels (DRLs), expressed as dose-length product (DLP), were calculated at 270 mGy.cm for women and 351 mGy. cm for men. Additionally, we summarized a case report demonstrating the practical utility and relevance of the Q-DRL-P in optimizing radiation dose management, highlighting a 40% reduction in radiation exposure while maintaining diagnostic quality
Conclusion: The Q-DRL-P is designed on robust theoretical and experimental foundations to establish and con tinuously refine DRL values. Whether it were implemented effectively, it would enable the optimization of ionizing imaging procedures, significantly reduce radiation exposure for patients and the Quebec population, with potential applications on a global scale. The Q-DRL-P aligns seamlessly with the international movement toward dose opti mization in medical imaging, contributing to the emerging concept of green medical imaging that we are pioneering.
