Assessment of PD-L1 Expression in Non-Small Cell Lung Cancers Using [⁶⁸Ga]Ga-DOTA-WL12 PET/CT

Assessing programmed death ligand-1 (PD-L1) expression in non-small cell lung cancer (NSCLC), particularly in metastatic cases, remains challenging. In this study, surface plasmon resonance (SPR) analysis and [⁶⁸Ga]Ga-DOTA-WL12 micro-PET/CT imaging are performed. [⁶⁸Ga]Ga-DOTA-WL12 PET/CT and [¹⁸F]FDG PET/CT are performed on a cohort of 20 patients with NSCLC. Semi-quantitative assessments include SUVmax, metabolic tumor volume (MTV), total lesion glycolysis (TLG), and target-to-background ratio (TBR). DOTA-WL12 exhibits robust PD-L1 binding with a KD value of 0.2 nM. Subsequent human studies reveal significant correlations between PD-L1 expression and the [⁶⁸Ga]Ga-DOTA-WL12 SUVmax in primary and metastatic lesions, surpassing the [¹⁸F]FDG results (r = 0.8889, p <0.0001 vs r = 0.0469, p = 0.8127). Notably, [⁶⁸Ga]Ga-DOTA-WL12 imaging discerned SUVmax and TBR differences between PD-L1 TPS ≤1% and PD-L1 TPS > 1% groups (p all <0.001). In an NSCLC patient with brain metastases, [⁶⁸Ga]Ga-DOTA-WL12 shows a SUVmean of 0.04 in the brain background, with TBR values of 17 and 23, underscoring its potential for detecting brain metastases. The study provides initial evidence for the clinical utility of [⁶⁸Ga]Ga-DOTA-WL12 PET/CT for lesion detection, immunotherapy selection, and therapeutic efficacy evaluation in PD-L1-expressing NSCLC, demonstrating its potential as a valuable tool in NSCLC research and management.