A Deep Learning-Based Assay for Programmed Death Ligand 1 Immunohistochemistry Scoring in Non-Small Cell Lung
Hiroaki Ito1, Akihiko Yoshizawa2, Kazuhiro Terada1
1Department of Diagnostic Pathology, Kyoto University Hospital, Kyoto, Japan.
Summary
An artificial intelligence (AI) system aids pathologists in determining the tumor proportion score (TPS) for programmed death ligand 1 (PD-L1) in non-small cell lung carcinoma. The AI tool proved most useful in cases where pathologists struggled with accurate TPS assessment.
Area of Science:
- Oncology
- Pathology
- Artificial Intelligence
Background:
- Programmed death ligand 1 (PD-L1) expression is crucial for predicting response to immunotherapy in non-small cell lung carcinoma (NSCLC).
- Accurate assessment of PD-L1 tumor proportion score (TPS) by pathologists is essential but can be challenging, leading to inter-observer variability.
Purpose of the Study:
- To develop and evaluate an artificial intelligence (AI) system to assist pathologists in calculating the PD-L1 TPS for the 22C3 assay in NSCLC.
- To assess the impact of AI-assisted systems on the accuracy and consistency of pathologists' TPS assessments.
Main Methods:
- An AI model was developed to calculate PD-L1 TPS, offering automated scoring and visualized overlay images.
- Four AI-assisted assessment methods were evaluated, involving pathologists' initial assessment followed by AI review, or AI review prior to pathologist assessment.
- Mixed-model analysis was used to compare the accuracy of AI-assisted methods against pathologists' independent scoring, particularly in discordant cases.
Main Results:
- Overall, AI-assisted TPS assessment did not significantly alter pathologists' scoring accuracy across all samples.
- In cases with discordant pathologist judgments (332 samples), AI-assisted methods significantly improved assessment accuracy (ORs ranging from 1.28 to 1.29, P < .012).
- No significant differences in accuracy were observed among the four AI-assisted methods when analyzing discordant cases.
Conclusions:
- AI-assisted systems show significant utility in improving the accuracy of PD-L1 TPS assessment in NSCLC, especially in challenging cases with inter-observer variability.
- The developed AI system can serve as a valuable tool to support pathologists, enhancing diagnostic consistency and potentially improving treatment decisions for NSCLC patients.
Keywords:
AI-assisted systemPD-L1deep learning-based assayimmunohistochemistrynon-small cell lung carcinoma

