# The predictive value of total body PET/CT in high PD-L1 expression and immunotherapy in advanced non-small cell lung cancer patients

## TL;DR

This study shows that total-body PET/CT can predict PD-L1 expression and immunotherapy outcomes in lung cancer patients.

## Contribution

The study introduces SUR-BP as a novel non-invasive biomarker for predicting immunotherapy response in NSCLC.

## Key findings

- Metabolic parameters from PET/CT, especially SUR-L, accurately predict high PD-L1 expression.
- SUR-BP ≥ 7.30 is associated with prolonged disease-free survival in immunotherapy-treated patients.
- Total-body PET/CT addresses spatial heterogeneity in PD-L1 assessment for better prognosis.

## Abstract

Total-body positron emission tomography/computed tomography (PET/CT) using uEXPLORER scanners demonstrates superior imaging capabilities for assessing programmed death ligand 1 (PD-L1) expression heterogeneity between primary tumors (PTs) and metastatic tumors (MTs) in advanced nonsmall cell lung cancer (NSCLC).

This retrospective study of 99 treatment-naïve NSCLC patients revealed that metabolic parameters (SUVmax, SUR-L, and SUR-BP) derived from biopsy-correlated PET/CT sites significantly predicted high PD-L1 expression (TC ≥ 50% or IC ≥ 10% by IHC).

SUR-L exhibited the highest diagnostic accuracy (AUC = 0.758, p < 0.001). Among 30 immunotherapytreated patients, PD-L1 positivity and SUR-BP ≥ 7.30 were associated with prolonged disease-free survival (DFS) (p = 0.012 and p = 0.035, respectively).

Our findings establish SUR-BP as a novel non-invasive biomarker for immunotherapy prognosis in NSCLC, addressing spatial heterogeneity challenges in PD-L1 assessment.