Computed Tomography Features associated With the Eighth Edition TNM Stage Classification for Thymic Epithelial Tumors

Area of Science:

• Oncology
• Radiology
• Thoracic Surgery

Background:

• The eighth edition TNM classification now includes staging for thymic epithelial tumors (TETs).
• Accurate staging of TETs is crucial for patient management and treatment planning.
• Preoperative imaging, specifically CT, offers potential for improved staging accuracy.

Purpose of the Study:

• To investigate the association between preoperative CT scan characteristics and the AJCC/UICC pathologic TNM stage of TETs.
• To identify specific CT features predictive of advanced TET stage.

Main Methods:

• Retrospective analysis of 54 patients diagnosed with TET who underwent curative intent surgery.
• Review of preoperative CT imaging by blinded specialists, assessing 15 International Thymic Malignancy Interest Group standard report terms.
• Development of a weighted scoring system using a Lasso-regularized multivariate model to predict TNM stage.

Main Results:

• Specific CT features correlated with higher pathologic TNM stage: elevated hemidiaphragm (score 6), vascular endoluminal invasion (score 6), pleural nodule (score 2), lobulated contour (score 2), and heterogeneous internal density (score 1).
• The developed model achieved an area under the receiver operating characteristic curve of 0.76, indicating moderate predictive performance.

Conclusions:

• Preoperative CT findings, including invasive or metastatic features, lobulated contour, and heterogeneous internal density, are associated with higher AJCC/UICC pathologic TNM stage in TETs.
• These CT-based imaging features can aid in the preoperative assessment of TETs.
• Further validation in an independent patient cohort is necessary to confirm these findings.