Development of image quality related reference doses called acceptable quality doses (AQD) in paediatric CT exams in Qatar

Revising and exploring the variations in methodologies for establishing the diagnostic reference levels for paediatric PET/CT imaging

PET-computed tomography (PET/CT) is a hybrid imaging technique that combines anatomical and functional information; to investigate primary cancers, stage tumours, and track treatment response in paediatric oncology patients. However, there is debate in the literature about whether PET/CT could increase the risk of cancer in children, as the machine is utilizing two types of radiation, and paediatric patients have faster cell division and longer life expectancy. Therefore, it is essential to minimize radiation exposure by justifying and optimizing PET/CT examinations and ensure an acceptable image quality. Establishing diagnostic reference levels (DRLs) is a crucial quantitative indicator and effective tool to optimize paediatric imaging procedures. This review aimed to distinguish and acknowledge variations among published DRLs for paediatric patients in PET/CT procedures. A search of relevant articles was conducted using databases, that is, Embase, Scopus, Web of Science, and Medline, using the keywords: PET-computed tomography, computed tomography, PET, radiopharmaceutical, DRL, and their synonyms. Only English and full-text articles were included, with no limitations on the publication year. After the screening, four articles were selected, and the review reveals different DRL approaches for paediatric patients undergoing PET/CT, with primary variations observed in patient selection criteria, reporting of radiation dose values, and PET/CT equipment. The study suggests that future DRL methods for paediatric patients should prioritize data collection in accordance with international guidelines to better understand PET/CT dose discrepancies while also striving to optimize radiation doses without compromising the quality of PET/CT images.

Paediatric diagnostic reference levels for common radiological examinations using the European guidelines

OBJECTIVE

The purpose of this study was to explore the feasibility to determine regional diagnostic reference levels (RDRLs) for paediatric conventional and CT examinations using the European guidelines and to compare RDRLs derived from weight and age groups, respectively.

METHODS

Data were collected from 31 hospitals in 4 countries, for 7 examination types for a total of 2978 patients. RDRLs were derived for each weight and age group, respectively, when the total number of patients exceeded 15.

RESULTS

It was possible to derive RDRLs for most, but not all, weight-based and age-based groups for the seven examinations. The result using weight-based and age-based groups differed substantially. The RDRLs were lower than or equal to the European and recently published national DRLs.

CONCLUSION

It is feasible to derive RDRLs. However, a thorough review of the clinical indications and methodologies has to be performed previous to data collection. This study does not support the notion that DRLs derived using age and weight groups are exchangeable.

ADVANCES IN KNOWLEDGE

Paediatric DRLs should be derived using weight-based groups with access to the actual weight of the patients. DRLs developed using weight differ markedly from those developed with the use of age. There is still a need to harmonize the method to derive solid DRLs for paediatric radiological examinations.

The cumulative radiation dose paradigm in pediatric imaging

Medical imaging professionals have an accountability for both quality and safety in the care of patients that have unexpected or anticipated repeated imaging examinations that use ionizing radiation. One measure in the safety realm for repeated imaging is cumulative effective dose (CED). CED has been increasingly scrutinized in patient populations, including adults and children. Recognizing the challenges with effective dose, including the cumulative nature, effective dose is still the most prevalent exposure currency for recurrent imaging examinations. While the responsibility for dose monitoring incorporates an element of tracking an individual patient cumulative radiation record, a more complex aspect is what should be done with this information. This challenge also differs between the pediatric and adult population, including the fact that high cumulative doses (e.g.,>100 mSv) are reported to occur much less frequently in children than in the adult population. It is worthwhile, then, to review the general construct of CED, including the comparison between the relative percentage occurrence in adult and pediatric populations, the relevant pediatric medical settings in which high CED occurs, the advances in medical care that may affect CED determinations in the future, and offer proposals for the application of the CED paradigm, considering the unique aspects of pediatric care.

Five-star rating system for acceptable quality and dose in CT

KEY POINTS

• Recent papers have shown examples of the methodology involved in integrating image quality with radiation dose and assessing acceptable quality dose (AQD).• As a further step in that direction, translating a 5-point score into a 5-star rating shall be helpful for wider and uniform application and shall be in line with the popular use of the 5-star rating.