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 (TLG_41%) and a threshold adapted to the CT volume (TLG_CT). 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.