Optimizing scan duration and tracer dose in radiomic analysis for 18F-FDG PET/MR brain cancer

Abstract

Objectives: This study is to optimize scan duration and tracer dose in radiomic analysis for 18F-FDG PET/MR brain cancer. Methods: Seventeen patients with brain cancer underwent PET/MR scans with injection of 3.70 MBq/kg 18F-FDG. PET images were split into 5 (PETSD5), 10 (PETSD10), 15 (PETSD15), and 25 (PETSD25) min duration groups, and the injected dose for each group with 10% (PETD10%), 20% (PETD20%), 33% (PETD33%) and 50% (PETD50%) dose levels were then simulated. 93 radiomic features were extracted and ICC was calculated for each feature between groups, respectively. Results: ICC varied with the feature type, scan duration, and tracer dose. ICC for PETSD10, PETSD15, and PETSD25 in relation to PETSD5 showed an obviously decrease with the lengthen of scan duration and the reduction of tracer dose. ICC on PETD10%, PETD20%, PETD33%, and PETD50% in relation to full-dose PET gradually increased with the enlargement of tracer dose and the extending of scan duration. ICC on different combinations with respect to PETSD5 at full-dose presented similar trends in most features for PETSD10 at 50%, PETSD15 at 33%, and PETSD25 at 20%. Besides, 28 features were non-sensitive to different scan durations and/or dose levels. The intertations between features were slightly affected by different scan durations and/or dose levels, in which discrepancies were sensitive to the specific feature type. Conclusions: PETSD10 at 50% might be the clinically adaptable solution for 18F-FDG PET/MR brain cancer, showing reduced radiation burden, better compatibility and clinical feasibility. Changes in scan duration and/or tracer dose in PET should be approached with caution.