ESTRO 2024 - Abstract Book

S1186

Clinical - Head & neck

ESTRO 2024

Moreover, besides salivary flow, radiation dose also affects patient-reported xerostomia. In line with previous findings, higher D mean,SCR increased XER DAY scores (p=0.09 [M6], p=0.03 [M12]), but not XER NIGHT scores (p≥0.33). Furthermore, D mean,oral affected XER DAY (p=0.05 [M12]) while D mean,sub affected XER NIGHT (p=0.01 [M6]). To test whether the negative effect of dose to salivary glands on xerostomia was achieved through reduced saliva production, the observed relations between dose and xerostomia were corrected for salivary flow. Indeed, the significant effect of D mean,SCR on xerostomia disappeared after adding FLOW PAR and FLOW SMSL to the models. Thus, D mean,SCR only increased XER DAY scores via reducing FLOW PAR , whereas the effects of D mean,oral and D mean,sub on xerostomia were independent of FLOW PAR and FLOW SMSL .

Conclusion:

Dose to Stem Cell Rich region (D mean,SCR ) reduces parotid gland saliva production, leading to higher patient-reported daytime xerostomia scores. No other influences of D mean,SCR on xerostomia were observed. Consequently, D mean,SCR should be minimized to preserve salivary flow with aiming at reducing the risk of daytime xerostomia.

Keywords: Parotid stem cells, xerostomia, salivary flow