Asiasafe/Asian Oceanian Society of Radiology (AOSR) Responses
Public Consultation of ICRP TG 108 Part Two
‘Practical Aspects in Optimisation of Radiological Protection in Digital Radiography, Fluoroscopy, and CT’
The report provides practical, systematic methods for optimizing radiation doses in our daily practice—from machine parameters settings, imaging workflow, protocol development, the collaboration between multidisciplinary professionals, etc., to a higher degree of harmonization of these optimization processes across multi-specialty clinical teams and equipment types within our healthcare system.
Procedures Appropriateness
As said in the report, the very first step to basic level of optimization is to justify the appropriateness of the referrals. Radiographers usually are the first medical imaging professionals to interact with patients when they arrive for examinations. We need to review examination requests carefully to prevent unnecessary duplication and to ensure clinical appropriateness as related to the patient’s history and indications. We
should consult with the radiologist and/or referring clinician before proceeding if there is a possibility that the examination might not be clinically appropriate.
Though it might be outside of the scope of this publication, the development of referral guidelines for appropriate imaging studies would be helpful in reducing patients’ radiation exposure.
For the pediatric age group, it is advisable to vet each imaging request by radiologists to make sure the use of radiation is appropriate and justified to answer the specific clinical question. As also stated in the report, radiation free modalities should be used when it is suitable and resources allow.
Education and Practice
It says in the report that “... set out three building blocks on which strategies for achieving optimization should be built (ICRP, 2022). The cornerstone is professionalism...” As a radiographer, the statement is absolutely undeniable. Technological advances in our profession are ongoing, and the various exposure techniques that radiographers can use continue to evolve. Just like using an iPhone, digital imaging technologies are extremely capable, but you need to know how to use them to unlock their potential. Radiographers should be proactive and familiar with the most current dose reduction techniques and must operate equipment optimally in accordance with safety and image quality policies and procedures. In order to attain this, the need for increased education and training for both entry-level and experienced radiographers, who will perform more complex examinations (e.g. CT or interventional fluoroscopy examination), must be enforced.
The roads to optimization are complex and cannot be solved by a single person, organization or regulatory entity. However, all of these changes will bring improved patient care, ensure patients’safety and imaging accuracy, those who perform imaging examinations should be ready to meet the challenge.
Comments on pediatric procedures
Keeping patients still for imaging is always a challenge in the pediatric age group. Suboptimal immobilization results in repeated exposures and increased radiation dose. Apart from the excellent suggestions in the publication, involvement of play specialists can also help in calming children and keeping them still for imaging studies. For young infants, feed-and-sleep approach can be considered for keeping the patient still for non-painful procedures. Collaboration between teams experienced in handling children optimize these strategies to reduce need of sedation yet improving imaging outcomes.
For CT in children, protocoling for each study is important to minimize the dose used to answer specific clinical questions. Discussion should be made between radiologists and referring clinicians to make sure the scan is tailored for the clinical question being asked. Protocoling should be done by preferably by pediatric radiologists to reduce the phases taken. Contrast medium should only be used when absolutely required. Split dose technique should be considered to reduce the number of phases acquired. Pre-contrast images should only be acquired when absolutely needed.
Related to the variable body size of children, optimal positioning of patient in the center of CT gantry is crucial to reduce radiation dose. Body parts not to be imaged or instruments (such as infusion pumps or other monitoring devices) should be removed from the field of view to avoid raising the radiation dose unnecessarily. These can hugely affect the radiation exposure in children with small body size.
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 diagnosis and 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 caregivers, 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 needs 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.
Compiled by
Asiasafe Chair, Prof K H Ng
Feb 1 2023