Draft report: Practical Aspects in Optimisation of Radiological Protection in Digital Radiography, Fluoroscopy, and CT
Abstract
Digital radiology is playing an increasingly important role in medicine world-wide. The use of computed tomography (CT) has risen dramatically in recent decades and makes up about half of the population dose from medical exposures in many parts of the world. In addition, ever more complex interventional procedures guided by fluoroscopy are replacing more invasive surgical techniques, thus substituting risks from surgery with lesser ones from radiation. These radiological techniques provide significant health benefits, but the associated radiation dose levels need to be kept commensurate with the benefit accrued. Key factors in achieving this are ensuring that examinations are only carried out when they can contribute to management of a patient’s condition and that the radiological protection aspects for all exposures are optimised. The latter is the subject of the present publication. Digital imaging data contribute versatility in image acquisition, post-processing, and presentation, and provide opportunities for optimisation. However, unlike their analogue equivalent, images acquired digitally may not provide an indication that a dose is too high or images are not collimated, so there are new problems that have to be addressed. In Publication 15x (ICRP, 2022), three fundamental requirements for taking the optimisation process forward were described. These are 1) the need for collaboration between radiologists and other physicians, radiographers, medical physicists and managers, 2) access to the appropriate methodology, technology and expertise, and 3) provision of organisational processes that ensure tasks, such as equipment performance tests, patient dose surveys and reviews of protocols are carried out. A high-level requirement is the integration and use of decision sciences, and harmonisation of these optimisation processes across multispecialty clinical teams and equipment types within healthcare systems. This publication contains information on practical methods needed to carry optimisation forward for different imaging techniques; radiography, fluoroscopy (and fluoroscopically guided interventional procedures) and CT. Many features of digital equipment allow dose levels to be reduced while still maintaining adequate image quality for the clinical task. Staff need to understand the relationship between the different selectable options to use the features effectively. However, there is a wide range in available equipment and training around the world. Provision ranges from clinics with simple radiographic units to specialist hospitals with complex state-of-the-art equipment. Some countries have established communities of medical physicists, while in others there is little or no medical physics support. This presents challenges in communicating requirements for optimisation. This document addresses these challenges by providing information for facilities, within broad categories linked to optimisation arrangements already in place, D: Preliminary, C: Basic, B: Intermediate, and A: Advanced (ICRP, 2022). It is hoped that through this approach, radiology teams will be able to plan strategies for introducing optimisation techniques that are appropriate for their own facilities and equipment.