Table 5. External validation between HNSCC and NPC cohorts.
| Input data | model | AUC | Brier (scaled) | R2 Nagelkerke | Omnibus | HL |
|---|---|---|---|---|---|---|
| NPC-3m | HNSCC-3m | 0.79 (0.76–0.83) | 0.30 | 0.31 | <0.001 | 0.14 |
| NPC-12m | HNSCC-12m | 0.77 (0.74–0.80) | 0.29 | 0.46 | <0.001 | 0.12 |
| HNSCCC-3m | NPC-3m | 0.73 (0.69–0.77) | 0.28 | 0.35 | <0.001 | 0.09 |
| HNSCC-12m | NPC-12m | 0.79 (0.77–0.82) | 0.31 | 0.41 | <0.001 | 0.17 |
Abbreviation: AUC: Area under the receiver operating characteristic curve; HNSCC: head and neck squamous cell carcinoma; NPC: nasopharyngeal carcinoma; XER: Xerostomia; XER3m or 12m: patient-reported moderate- to-severe xerostomia after 3- or 12-month; Dmean-c: mean dose to the contralateral parotid glands; Dmean-i: mean dose to the ipsilateral parotid glands; HL: Hosmer–Lemeshow test.