Effective radiation dose reduction in total body PET/CT while improving diagnostic value

Abstract

Background ¹⁸F-FDG positron emission tomography (PET) combined with computed tomography (CT) has become an indispensable imaging modality in clinical practice. However, the extent of radiation exposure patients receive with an effective radiation dose has always been a concern of radiological protection. The aim of the current study was to estimate the effective doses in total-body PET/CT scans that reasonably reduced the internal radiation-absorbed dose from PET and effectively controlled the external radiation-absorbed dose from CT. Methods Patient doses were calculated, including internal radiation-absorbed dose from PET and external radiation-absorbed dose from CT, using a total-body PET/CT scanner. Results The results showed an average radiation dose of 2.43 ± 0.36 mSv and 13.08 ± 1.37 mSv for the PET and CT components, respectively, resulting in a total dose of 15.51 ± 1.71 mSv. The diagnostic CT scan protocols contributed 84% of the overall effective radiation doses, which was larger than the percentage contributed by the PET component (16%). Conclusions The injection dose was 1.85 MBq/kg, which was decreased to 1/3 that of conventional activity (5.55 MBq/kg). Reducing the diagnostic dose using the technology of automatic exposure control (AEC) will be helpful in decreasing the effective radiation doses of PET/CT scan.