The effect of reduced scan time on response assessment FDG-PET/CT imaging using Deauville score in patients with lymphoma

Purpose[F-18]Fluoro-deoxy-glucose positron emission tomography/computed tomography (FDG-PET/CT) is used for response assessment during therapy in Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Clinicians report the scans visually using Deauville criteria. Improved performance in modern PET/CT scanners could allow for a reduction in scan time without compromising diagnostic image quality. Additionally, patient throughput can be increased with increasing cost-effectiveness. We investigated the effects of reducing scan time of response assessment FDG-PET/CT in HL and NHL patients on Deauville score (DS) and image quality.MethodsTwenty patients diagnosed with HL/NHL referred to a response assessment FDG-PET/CT were included. PET scans were performed in list-mode with an acquisition time of 120s per bed position(s/bp). From PET list-mode data images with full acquisition time of 120s/bp and shorter acquisition times (90, 60, 45, and 30s/bp) were reconstructed. All images were assessed by two specialists and assigned a DS. We estimated the possible savings when reducing scan time using a simplified model based on assumed values/costs for our hospital.ResultsThere were no significant changes in the visually assessed DS when reducing scan time to 90s/bp, 60s/bp, 45s/bp, and 30s/bp. Image quality of 90s/bp images were rated equal to 120s/bp images. Coefficient of variance values for 120s/bp and 90s/bp images was significantly