Impact assessment of [18F]FDG PET/CT in predicting EGFR gene mutation status in patients with lung adenocarcinoma using recovery coefficient-based correction of semi-quantitative and volume-based PET metrics

Abstract The aim of this study was to assess the impact of [18F]FDG PET/CT in predicting EGFR gene mutation status in patients with lung adenocarcinoma using recovery coefficient-based (RC-based) correction of semi-quantitative and volume-based PET metrics. A retrospective multi-center study included 63 patients diagnosed with lung adenocarcinoma who underwent [18F]FDG PET/CT. Acquisition was performed according to the EANM guidelines using two EARL-accredited PET/CT-systems. All patients were divided into an EGFR-mutant (n=30) and a wild-type (n=33) groups based on the results of molecular testing. Maximal diameter and CT volume of each primary tumor lesion were measured. [18F]FDG uptake was evaluated by measurement of semi-quantitative and volume-based PET metrics such as SUVmax, SUVpeak, MTV, and TLG. TLG was measured using PET segmentation method by 3D-Isocontour tool with a 41% of SUVmax threshold (TLG41%) and a threshold adapted to the CT volume (TLGCT). Additionally, TLR was calculated as the ratio of tumor SUVpeak to liver SUVmean. Acquisition data of the NEMA IEC Body Phantom Set NU2–2018 were applied for plotting the RC curves which were used for following RC-based correction of PET metrics. No significant difference in tumor lesion maximal diameter, CT volume, evaluated values of PET metrics before and after RC-based correction was found between the EGFR-mutant and wild-type groups (p > 0.05). Observed semi-quantitative and volume-based PET metrics obtained from [18F]FDG PET/CT have no significant value for predicting EGFR gene mutation status in patients with lung adenocarcinoma, regardless of whether RC-based correction is applied.