KEY POINTS
- This retrospective multicenter study included 716 patients with human papillomavirus-positive oropharyngeal cancer from three public datasets: 390 in training, 166 in internal validation, and 160 in an independent test set.
- The model used planning computed tomography radiomics extracted separately from the primary gross tumor volume and metastatic nodal gross tumor volume, then compared primary-only, physically fused, and feature-level fusion strategies.
- The feature-level primary-plus-nodal strategy performed best; the XGBoost radiomics model reached area under the curve values of 0.907, 0.852, and 0.835 in training, internal validation, and independent testing.
- The clinical-radiomics nomogram based on multi-regional features reached an area under the curve of 0.934 in training, 0.920 in internal validation, and 0.908 in the independent test set.
- In the independent test set, the multi-regional combined model outperformed the primary-only combined model — 0.908 versus 0.857, p = 0.034.
CLINICAL TAKEAWAY
This study supports the idea that nodal radiomics may add prognostic information beyond primary-tumor radiomics in human papillomavirus-positive oropharyngeal cancer. For now, it is a risk-stratification research model, not a tool for treatment de-escalation or intensification decisions. The main limitations are retrospective public datasets, baseline imbalance in the external test set, manual contour dependence, absent radiotherapy dose data, and no prospective validation.