151751-Najiba-Chargi

220 CHAPTER 12 METHODS ETHICAL APPROVAL The design of this study was approved by the Medical Ethical Research Committee of the University Medical Center Utrecht (approval ID 17-365/C). All procedures in this study were in accordance with the ethical standards of the institutional and/or national research commit- tee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. PATIENTS AND STUDY DESIGN We conducted a retrospective study of HNSCC patients treated with primary or adjuvant concomitant cetuximab and radiotherapy in the University Medical Center Utrecht between January 2007 and December 2018. The included patients were unfit for cisplatin treatment. HNSCC patients were included if they had a pre-treatment (≤ 3 months prior) diagnostic im - aging scan (CT or MRI) of the third cervical vertebra (C3) level which was suitable for muscle segmentation. Patients were excluded if treatment was provided with palliative intent. Rele - vant demographic and clinical variable such as age at diagnosis, sex, weight, length, bodymass index (BMI), alcohol consumption, alcohol abuse as identified by the treating physician, co - morbidity as expressed by the Adult Comorbidity Evaluation-27 (ACE-27), tumor, lymph nodes, and metastasis (TNM) staging, treatment regimen, cetuximab DLT data, date of last follow up, and eventually, the date of recurrent disease or death were obtained from patients’ records. IMAGE ANALYSIS AND MEASUREMENTS The cross-sectional area (CSA) of skeletal muscles was measured on pre-treatment diagnostic CT or MRI imaging that included the C3 vertebra. Segmentation of the muscle was performed using the commercially available SliceOmatic (Tomovision, Canada) by a single researcher (L.H.) on the axial slide which showed the entire vertebral arc as well as both transverse pro - cesses. The CT scans used were 3-mm axial slices with or without contrast made using Philips (16-slice or 64-slice) or Siemen’s scanners (40-slice) and the MRI scans were axial T1 weighted sequence without fat suppression made using Philips’s scanners (1.5T or 3T). CSA was calcu - lated as the sum of the measured area of both sternocleidomastoid muscles (SCM) and the paravertebral muscles. If tumor growth interfered with the measurement of either the left or right SCM, the area of the contralateral SCMwas used to replace it. Patients were excluded, if, the CSA could not be measured reliably due to a CT or MRI artifacts, a too small field of view, or tumor growth in both SCM. In the case of CT imaging, muscle area was measured semi-automatic using a combination of manual segmentation in a predefined radiodensity range of -29 to +150 Hounsfield units (HU). 14 In the case of MRI imaging, muscle area was measured manually. Figure 1 shows an example of muscle delineation at the C3 level. The CSA at C3 level was converted to the CSA at third