Stråldosreducering vid PET/CT- undersökningar : En litteraturöversikt

Sammanfattning

Radiation Dose Reduction in PET/CT ExaminationsBackground: Positron emission tomography combined with computed tomography (PET/CT) is an important diagnostic imaging method, particularly in oncology. However, the examination involves radiation exposure from both the administered radiopharmaceutical in the PET component and the X-rays from the CT component. Therefore, dose optimization is an important part of radiation safety, in accordance with the ALARA principle. The radiographer has a central role in ensuring that the examination is performed with the lowest reasonably achievable radiation dose without compromising diagnostic image quality. Aim: The aim of this study is to identify current strategies used to optimize and reduce patient radiation dose in ¹⁸F-FDG PET/CT examinations. Method: The study was conducted as a general literature review. A total of 17 quantitative scientific original articles addressing dose-reducing or dose-optimizing strategies in ¹⁸F-FDG PET/CT for adult patients were included. The articles were analyzed, and the results were compiled into an integrated results table. Results: The results show that radiation dose in ¹⁸F-FDG PET/CT can be reduced through several different strategies. PET-related strategies include reduced administered FDG activity, AI- or deep learning-based image optimization, total-body or LAFOV PET/CT systems, and optimized acquisition. CT-related strategies include ultra-low-dose CT, iterative reconstruction, and weight- or BMI-based protocol adaptation. The results also show that combined PET and CT optimization can reduce the total radiation dose in PET/CT examinations. Conclusion: Several strategies can be used to reduce patient radiation dose in ¹⁸F-FDG PET/CT. The largest dose reductions are mainly seen in the PET component, particularly with reduced FDG activity and the use of total-body or LAFOV systems. At the same time, the results show that dose reduction must be balanced against image quality and diagnostic reliability. Clinical implementation therefore requires clear protocols, patient adaptation, and quality assurance. Keywords: ¹⁸F-FDG PET/CT, ALARA, CT dose, dose optimization, dose reduction, iterative reconstruction, LAFOV, PET/CT, radiation safety, total-body PET/CT.