Workflow and radiation safety implications of (18)F-FDG PET/CT scans for radiotherapy planning.

Unlabelled: The use of (18)F-FDG PET/CT for radiotherapy planning may lead to better tumor volume definition. Reproduction of the patient's position when setting up an (18)F-FDG PET/CT scan for radiotherapy planning is more accurate if a radiation therapist is involved. The aim of this study was to compare setup time and staff radiation dose between radiation therapists and nuclear medicine technologists.

Methods: Forty patients with newly diagnosed head and neck or non-small cell lung cancer were prospectively recruited into this study. Twenty patients (10 with head and neck cancer and 10 with non-small cell lung cancer) underwent (18)F-FDG PET/CT for radiotherapy planning, and 20 patients (10 with head and neck cancer and 10 with non-small cell lung cancer) underwent (18)F-FDG PET/CT for staging. Setup time was measured, and a radiation monitor recorded the highest dose (μSv/h) to staff during setup.

Results: For radiation therapists, the mean setup time for a lung scan (in min:s) was 5:22 ± 2:11 (range, 2:22-9:23), with a highest dose of 4.94 ± 3.78 μSv (range, 2.02-15.23 μSv), and the mean setup time for a head and neck scan was 4:49 ± 1:45 (range, 2:03-8:21), with a highest dose of 3.93 ± 1.45 μSv (range, 1.19-6.83 μSv). For nuclear medicine technologists, the mean setup time for a lung scan was 1:58 ± 0:24 (range, 1:17-2:38), with a highest dose of 3.30 ± 1.28 μSv (range, 1.92-5.47 μSv), and the mean setup time for a head and neck scan was 2:12 ± 0:38 (range, 1:03-3:16), with a highest dose of 3.10 ± 1.78 μSv (range, 1.56-7.49 μSv).

Conclusion: This study showed that setup time and operator radiation dose were greater for radiation therapists setting up planning (18)F-FDG PET/CT scans than for nuclear medicine technologists setting up routine (18)F-FDG PET/CT scans. These results have implications for scheduling of radiotherapy planning PET/CT; however, the additional radiation dose was not considered to be significant.