ESTRO 2024 - Abstract Book

S1274

Clinical - Head & neck

ESTRO 2024

Results:

The CITOR models were developed based on patients with a tumour in the larynx, pharynx or oral cavity, whereas the US cohort consisted of oropharyngeal cancer patients only. Moreover, treatment differed in many aspects (e.g. variations in target area definitions, dose prescriptions, split field radiation, and proton vs. photon therapy). Prevalences of moderate-to-severe toxicities at 6 months for both the development and external cohorts are depicted in Figure 1. Overall, performance of the CITOR models in the US cohort was comparable to the previously published validation performance (Table 1). Calibration was reasonable with applying the model with its original coefficients, while refitting the model to the MDACC population improved calibration, yet not improving the AUC substantially (Table 1- bottom row).