151751-Najiba-Chargi

221 Systemic therapy: skeletal muscle mass and bioradiotherapy lumbar vertebra L3 level using the formula previously published by Swartz et al . 6 The CSA at L3 level was corrected for squared height to create the lumbar skeletal muscle index (LSMI). Figure 1. Example of delineation on 3 mm axial slide of CT (Siemens 40-slice) (left) and axial T1 weighted sequence MRI (Philips 1.5T) (right) at the level of C3 using SliceOmatic. The left and right SCM as well as the paravertebral muscles are delineated excluding the trapezius muscle. Please note that the muscles in the anterior neck are not included in the delineation as previously described 164 with the measurement of either the left or right SCM, the area of the contralateral SCM was 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 lumbar vertebra L3 level using the formula previously published by Swartz et al. 6 The CSA at L3 level was corrected for squared height to create the lumbar skeletal muscle index (LSMI). i . Example of delineation on 3 mm axial slide of CT (Siemens 40-slice) (left) and axial T1 weighted sequence MRI (Philips 1.5T) (right) at the level of C3 using SliceOmatic. The left and right SCM as well as the paravertebral muscles are delineated excluding the trapezius muscle. Plea e note that the muscles in the anterior neck are not included in the delineation as previously described DOSE-LIMITING TOXICITY DLT was defined as any toxicity that resulted in a treatment postponement of ≥ 4 days, dose reduction of ≥ 50%, dose omission, or termination of cetuximab treatment before complet - ing the predetermined cetuximab regimen (most commonly consisting of eight cycles, none extending beyond last radiotherapy fraction). SURVIVAL OS was defined as the time between the date of diagnosis and the date of death or the date of the last follow up. DFS was defined as the time between the date of diagnosis and the date of recurrence or the date of the last follow up. STATISTICAL ANALYSIS Statistical analysis of the data was performed using IBM SPSS statistics 25. Descriptive sta - tistics for categorical variables were presented as frequencies and percentages. Continuous variables with normal distribution were presented as mean with standard deviation (SD), while those with skewed distribution were presented as median with interquartile range (IQR). The means of the continuous variables with the presence or absence of low SMM were com- puted using the independent sample t-tests. The percentages of the categorical variables with the presence or absence of low SMM were analyzed using the Pearson’s or Mantel-Haenszel 12