151751-Najiba-Chargi

321 Systemic therapy: skeletal muscle mass and functional outcomes Figure 1 Percentages of ‘missed’ patients per accrual year. ‘Missed’ patients are defined as patients who were eligible and willing to participate but data at t0 was not collected. BASELINE CHARACTERISTICS Baseline characteristics are presented in table 1. Of the 108 included patients, 73 (67%) were male, 53 patients (49%) had an ACE-27 score > 0 indicating comorbidity, 49 patients (45%) had sarcopenia, 35 patients (32%) had a tumor located in the base of tongue, 80 (74%) had stage IV disease and 70 (68%) were HPV positive. There were no significant differences regarding these characteristics between the patients present at the different assessments. Patients who were excluded because only t 0 data was available ( n = 34), had higher tumor stages, and had more often a modified diet pretreatment (FOIS < 7) and trismus. Patients who were eligible but not included in the study ( n = 84) were comparable to the included patients with regard to patient, tumor and treatment characteristics. However, baseline BMI, SMM, presence of sarcopenia, FOIS andmouth opening were not available for these patients. Of the 108 included patients, 42 were treated with RT only (39 by tumor indication and 3 because they were unfit for systemic therapy), and 66 with RT+ (49 with cisplatin and 17 with cetuximab). Patients treated with RT+ more often had pretreatment sarcopenia, obviously had higher tumor stages, and more often had HPV negative tumors. All baseline characteristics categorized by treatment modality are presented in appendix 2. 17