Radiolabelled anti-PD-L1 peptide PET/CT in predicting the efficacy of neoadjuvant immunotherapy combined with chemotherapy in resectable non-small cell lung cancer.

Background: This study aimed to evaluate the predictive value of baseline PD-L1 targeted peptide ⁶⁸Ga-NOTA-WL12 PET/CT in neoadjuvant immunotherapy combined with chemotherapy of resectable NSCLC.

Methods: Patients with resectable NSCLC (n = 20) enrolled in this prospective study received baseline paired ⁶⁸Ga-NOTA-WL12 PET/CT and ¹⁸F-FDG PET/CT. After 2-4 cycles of toripalimab plus nab-paclitaxel and cisplatin, surgery was performed if R0 resection was available. The major pathologic response (MPR) state of the post-operative specimen was recorded. The imaging parameters of the ⁶⁸Ga-NOTA-WL12 PET/CT, ¹⁸F-FDG PET/CT and CT between the MPR and non-MPR groups and their predictive efficacy of MPR were compared.

Results: Among 20 patients, 17 patients underwent surgery, 10 achieved an MPR and 7 did not. The SUV_max and tumour-to-blood pool (TBR) of baseline ⁶⁸Ga-NOTA-WL12 in the MPR group were higher than those in the non-MPR group, and the difference in TBR was statistically significant. The ΔSUL_peak% of ¹⁸F-FDG exhibited differences between the MPR and non-MPR groups with no significance. Baseline ¹⁸F-FDG PET/CT parameters and ΔD% failed to differentiate the two groups. The areas under the ROC curves of SUV_max, TBR in ⁶⁸Ga-NOTA-WL12 PET/CT, ΔD% and ΔSUL_peak% in ¹⁸F-FDG PET/CT were 0.76, 0.79, 0.71 and 0.80, respectively, in predicting MPR.

Conclusion: Baseline ⁶⁸Ga-NOTA-WL12 PET/CT has a potential to predict the pathological response of neoadjuvant immunotherapy combined with chemotherapy in patients with resectable NSCLC, whose efficacy is comparable to that of therapy evaluations employing baseline and follow-up CT and ¹⁸F-FDG PET/CT examinations.

Trial registration: NCT04304066, registered 13 November 2020, https://register.

Clinicaltrials: gov/prs/app/action/SelectProtocol?sid=S000AEI9&selectaction=Edit&uid=U000503E&ts=2&cx=-awajet .