ESTRO 2021 Abstract Book

S842

ESTRO 2021

Conclusion ENE infiltrating surrounding structures, CLN MAD>3cm and big RLN were all the independent prognostic value for NPC and can be criteria for future N stage. Only Nomo and ENE3 showed better performance than current N stage. Simply upgrading ENEmax to N3 made the difference between N1 and N2 insignificant, thus should be considered with caution. PO-1013 Mastication, swallowing and salivary flow in patients with HNC; objective tests versus PROs J. Vermaire 1 , C. Raaijmakers 1 , I. Verdonck-de Leeuw 2 , F. Jansen 2 , C. Terhaard 1 , C. Speksnijder 3 1 UMCU, Radiation Oncology, Utrecht, The Netherlands; 2 Vrije Universiteit, Otolaryngology-Head and Neck Surgery, Amsterdam, The Netherlands; 3 UMCU, Head and Neck Surgical Oncology, Utrecht, The Netherlands Purpose or Objective Before and after treatment for head and neck cancer (HNC), many patients experience problems with mastication, swallowing, and/or salivary flow. To determine oral functioning, objective and subjective measures can be used. Objective measures are based on how well a person can perform a task, irrespective of what they experience while performing the task. They are based upon an accurate representation of the world, and are unbiased because they record only what is observed. A person’s subjective evaluation depends on individual values and priorities, which may differ between persons and even within persons. This patient- reported outcome measure (PRO) is based on what persons actually experience, and is increasingly being integrated in routine clinical practice. It has shown to contribute to improved communication, patient satisfaction, earlier detection of problems, and more efficient use of health services. In order to develop strategies to reduce side-effects of treatment, it is important to know the relation between a patients’ subjective evaluation of his/her oral health and the objective function of the organs involved. The aim of this study was to investigate the association between objective test outcomes of mastication, swallowing and salivary flow versus subjective PROs. Materials and Methods A cohort study was used to collect data before treatment, and 3 and 6 months after treatment. Spearman’s rho was used to test the association between objective test outcomes Mixing Ability Test (MAT) for masticatory performance, Water Swallowing Test (WST) for swallowing performance and the salivary flow test versus PROs (EORTC QLQ-H&N35, SWAL-QoL-NL and GRIX). Scatterplots were created to visualize the MAT, WST, and salivary flow outcomes that had the highest correlation with one of the PROs. Results Data of 142 patients were used, and in total 285 measurements were performed. No significant correlations were found between the MAT or WST and subscales of the EORTC QLQ-H&N35, and significant but weak correlations were found between 4 subscales of the SWAL-QoL-NL. Weak to moderate correlations were found between the salivary flow test and GRIX at 3 and 6 months after treatment, with the highest correlation for xerostomia during the day (Spearman’s rho=-0.441, p=0.001).