ESTRO 2025 - Abstract Book

S1058

Clinical – Head & neck

ESTRO 2025

Factors associated with prolonged PEG tube dependence shown in Table 1,

included smoking status (P = .012), mean dose to the superior constrictor muscle > 62 Gy (P = .003), mean dose to the middle constrictor muscle > 58 Gy (P = .005), mean oral cavity dose > 42 Gy (P < .001), mean dose to the lips > 15 Gy (P = .007), mean dose to the mandible > 50 Gy (P = .019), and mean dose to the larynx > 51 Gy (P = .04). Never smokers compared to former smokers (P = .006) and patients with a Karnofsky Performance Status (KPS) > 90 (P = .003) were more likely to remove the PEG tube within 3.3 months. In a multivariate model, significant predictors of prolonged PEG dependence were smoking status (P = .01), mean doses to the middle constrictor muscle (P = .008), oral cavity dose > 42 Gy (P < .001), and the protective effect observed in never-smokers (P = .001). Low dose planning target volume >238cc was borderline significant in the univariant model (P = .052) and significant in the multivariate model (P = .004). Conclusion: These findings strongly suggest that smoking during treatment and higher doses to organs at risk, mainly swallowing mechanism structures, are important modifiable factors to reduce the duration of PEG dependency in this population, potentially impacting survival.