Estimation of patient dose in (18)F-FDG and (18)F-FDOPA PET/CT examinations

To estimate specific organ and effective doses to patients resulting from the (18)F-FDG ((18)F-2-deoxy-D-glucose) and (18)F-FDOPA (6-fluoro-((18)F)-L-3, 4-dihydroxyphenylalanine) PET/CT examinations for whole body and brain.

Three protocols for whole body and three for brain PET/CT were used. The CTDI values were measured using standard head and body CT phantoms and also computed using a software CT-Expo for dose evaluation from the CT component. OLINDA software based on MIRD method was used for estimating doses from the PET component of the PET/CT examination.

The organ doses from (18)F-FDG and (18)F-FDOPA whole body and brain PET/CT studies were estimated. The total effective dose from a typical protocol of whole body PET/CT examination was 14.4 mSv for females and 11.8 mSv for male patients from (18)F-FDG, whereas it was 11 mSv for female and 9.1 mSv for male patients from (18)F-FDOPA. The total effective doses from a typical protocol for PET/CT studies of brain was 6.5 mSv for females and 5.1 mSv for males from (18)F-FDG whereas it was 3.7 mSv for females and 2.8 mSv for males from (18)F-FDOPA.

The effective radiation doses from whole body PET/CT examination was approximately 4-8 times higher than the background radiation dose from both (18)F-FDG and (18)F-FDOPA scans, while it was 1-3 times the background radiation dose from PET/CT scans of brain.