Optimizing Dose Reduction of 18F-FDG in Oncology PET/CT: Exploring Strategies to Minimize Radiation Exposure While Maintaining Diagnostic Efficacy.

Advances in PET scanner technology and long-axial-field-of-view systems have improved detection sensitivity, potentially allowing for the use of lower doses of ¹⁸F-FDG while still maintaining high-quality imaging. This study aimed to determine the lowest effective ¹⁸F-FDG dose for PET imaging that preserves diagnostic accuracy and image quality while reducing radiation exposure to the patient and technologist. Methods: Approximately 30 ¹⁸F-FDG PET/CT scans were acquired using a standard dose of 5 MBq/kg of ¹⁸F-FDG and a scan time of 2 min per bed position. List-mode data were reconstructed to simulate doses of 1, 2, 3, and 4 MBq/kg. Image quality was evaluated by 6 nuclear medicine physicians, each masked to study conditions, using both visual scoring and lesion conspicuity assessments. Results: Findings suggest that image quality and lesion conspicuity were acceptable to 3 MBq/kg, with significant degradation at lower doses. Statistical analysis confirmed that these differences were due to doses, not reader variability. Conclusion: Reducing the ¹⁸F-FDG dose from 5 to 3 MBq/kg in PET/CT imaging maintains image quality and diagnostic accuracy. This represents a 40% dose reduction, supporting dose revision to enhance patient and technologist safety while maintaining clinical efficacy.