Overcoming Tumor Segmentation Challenges in an International Multicenter Radiomics Study for Lung Cancer
Author Block: M. Spector1, N. Bogot1, V. Miskovic2, E. Oberstien3, A. Prelaj2, S. G. Armato4, N. Peled3, O. Benjaminov1, L. C. Roisman3; 1Israel/IL, 2Milano/IT, 3Jerusalem/IL, 4Chicago, IL/US
Purpose: Lung cancer is a global health challenge. Radiomics, extracts quantitative features from medical images, shows promise in optimizing tumor assessment, treatment planning and outcomes. Implementing radiomics challenges due to varied acquisition protocols, image parameters, and tumor characteristics. This study focuses on overcoming segmentation challenges in an international multicenter setting.
Methods or Background: This retrospective multicenter study enrolled patients with confirmed NSCLC diagnosed between 2012 and 2022. Chest CTs were acquired according to local standard-of-care protocols, collected, and pseudo-anonymized in DICOM format. After quality assessment, images underwent harmonization to address inter-institutional variability in acquisition parameters, and slice thickness and reconstruction kernels were standardized. Tumor segmentation focused on delineating regions of interest using automated and semi-automated methods, with manual corrections as needed.
Results or Findings: From 1,492 patients initially enrolled, 828 patients had chest CTs. One hundred (12%) post-surgical images or images without pulmonary lesions were excluded. Segmentation challenges were categorized into technical issues (77 patients, 9.3%) – including image dimensions or image acquisition - and tumor-related factors (84 patients, 10%), including complex anatomy, diffuse disease, or poorly defined borders. AI-based lung segmentation with ROI-based fast matching, followed by manual correction, was applied to 31 patients (3.7%). Ultimately, 597 patients (72%) were successfully segmented for radiomics analysis.
Conclusion: This study highlights the challenges in segmentation to developing a robust radiomic model for NSCLC in multicenter settings. By addressing the limitations of fully automated methods, segmentation accuracy improved, increasing the number of successfully segmented cases for radiomics analysis.
Limitations: The study's limitations include variability in acquisition protocols, potential selection bias from excluded cases, and manual segmentation corrections. Challenges with poorly defined tumors limit generalizability to advanced NSCLC, while incomplete follow-up data may impact the correlation between radiomic features and patient outcomes.
Funding for this study: Horizon 2020 Framework Program (EU Framework Program for Research and Innovation H2020), 101057695
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was conducted in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments. Ethical approval for the study was granted by the Ethics Committee of Shaare Zedek Medical Center (Approval number: 0240-22-SZMC).