Abstract
At a time when reducing the radiation dose to patients and the public has become a major focus, we assessed the radiation exposure rate from patients after an 18F-FDG PET/CT scan and evaluated different interventions to reduce it. Methods: 100 patients were enrolled in the study. Radiation dose rates were measured with an Ionization Survey meter after the scan in all patients. Patients were divided into 2 groups: Group 1- instructed to void then dose rates re-measured; Group 2a (pre-void)- wait 30 minutes then dose rates re-measured; Group 2b (post-void)- wait 30 minutes, void then dose rates re-measured. Results: 74/100 exceeded 20 μSv/h (2 mR/h) immediately after their scan. Group 1: mean dose rates decreased 20.0% from the post-scan measurement after voiding with 12/36 remaining at or above 20 μSv/h. Group 2a: mean dose rates decreased 23% from the post-scan measurement after waiting 30 minutes with 9/38 remaining at or above 20 μSv/h. Group 2b: mean dose rates decreased 35% from the post-scan measurement after waiting 30 minutes then voiding with 1/38 remaining at 20 μSv/h. Conclusion: Nearly 75% of patients undergoing an 18F-FDG PET/CT scan are exceeding 20 μSv/h when leaving the imaging facility. The most effective method to reduce radiation exposure was voiding after a 30 minute wait post-exam.