18F-FDG PET/CT to predict tumor PD-L1 expression and response to PD-(L)1 blockade in patients with non-small-cell lung cancer

摘要

Since the introduction of PD-(L)1 checkpoint inhibitor therapy for the treatment of non-small-cell lung cancer (NSCLC) there is a search for a biomarker that distinguishes responders from non-responders. A reliable biomarker has not been found yet. Tumor PD-L1 expression, assessed by immunohistochemistry (IHC) on a histological tumor sample, is at this point the most widely used and best validated biomarker. Absence of tumor PD-L1 expression predicts for a low overall response rate (ORR) of ~10%, while a tumor PD-L1 expression of ≥50% predicts for an ORR of 30% to 45% ( - ). To acquire enough tumor material in NSCLC for IHC testing and molecular analysis can be challenging. Frailty and comorbidities of patients and limited accessibility of lesions for biopsy on one hand and the increasing number of IHC and genetic tests being requested on the other hand are a constant challenge. Non-invasive techniques for tumor profiling are therefore attractive alternatives.