ESTRO 36 Abstract Book

S594 ESTRO 36 2017 _______________________________________________________________________________________________

showed no correlation between EGFR and nomogram score (ρ=0.29). After validating the existing nomogram with this new cohort, its performance was comparable to the published data 1 (C-index = 0.68). By performing multivariate Cox regression, the addition of EGFR to the nomogram improved its concordance index to 0.73 as shown in table 1. Interestingly we found that high-risk patients had lower EGFR levels in blood samples compared to low-risk patients. This is opposite to results obtained from tissue samples as reported in literature. 2

Weight loss is common after radiation treatment of head and neck cancer (H&N) as assessed by only pre/post measurements. Thus, only scarce data exists regarding body changes during overall treatment time. This study investigated changes in weight and body composition of H&N patients during radical radiation treatment, and correlated the findings to individual tests of muscle strength. Material and Methods Prospective study of 30 H&N patients undergoing IMRT (60- 68 Gy) during a 16 month period. Patients were followed weekly during treatment, and all had individualized nutritional counseling. At baseline, and with 2-week intervals during IMRT and 2 weeks after, patients underwent whole-body dual-energy X-ray absoptiometry (DXA) scans, as well as weight measurements and pre/post treatment maximal muscle strength tests (n=21)(one- repetition maximum chest press, leg press, and knee extension). Changes over time were analyzed by linear regression, and pre/post data were compared by Student’s paired t-tests. Results A total of 131 DXA scans were obtained. Mean age was 58.2, and the patients were predominantly stage II-IV (77%). Two-thirds received concomitant chemotherapy. Baseline BMI was 27.4 (± 4.8). Significant overall declines (p<0.001) were observed in weight (-8.2%; range +2.0 to - 18.4), fat mass (10.3%; range +2.4 to -29.1), and lean body mass (10.7%; range +0.8 to -23.9). All changes were mutually correlated in regression analysis, e.g., R 2 =0.74 (p<0.001) for weight loss versus lean body mass. The decline in lean body mass was correlated with loss of muscle strength as assessed by chest press (R 2 =0.61; p<0.001) and knee extension (R 2 =0.25; p=0.03), but not with leg press (p=.08). Concomitant chemoradiation was associated with a 10% decline in lean body mass in univariate analysis, however, no independent predictors were discerned in multivariate regression. Conclusion The overall weight loss during IMRT for H&N was 8.2%. Weight loss correlated proportionally with the percentage decline in both fat mass and lean body mass. Loss of lean body mass correlated well with loss of muscle strength during treatment. The proportional loss of fat and lean body mass indicates that physical exercise during radiotherapy may be required to favor muscle/fat distribution. EP-1090 Particle therapy and IMRT for patients with esthesioneuroblastoma: a single-institution experience J. Liermann 1 , M. Syed 1 , D. Bernhardt 1 , N. Bougatf 2 , S.B. Harrabi 1 , A. Paul 1 , T. Sprave 1 , S. Rieken 1 , T. Haberer 2 , K. Herfarth 1 , J. Debus 1 , H. Hauswald 1 , S. Adeberg 1 1 University Hospital of Heidelberg, Department of Radiation Oncology, Heidelberg, Germany 2 University Hospital of Heidelberg, Heidelberg Ion-Beam Therapy Center HIT, Heidelberg, Germany Purpose or Objective Esthesioneuroblastoma or olfactory neuroblastoma is a rare tumor entity originating from the olfactory neuroepithelium. There is only few data about the efficacy of different treatment strategies so far. Several approaches have been made and a combination of radiation and surgery is thought to be effective. Most tumors are situated in the nasal cavity and thus applied radiation therapy (RT) should be very precise. Intensity modulated radiotherapy (IMRT) and carbon ion radiotherapy (CIRT) are highly precise techniques with advanced dose conformity and improved sparing of organs at risk which might translate into improved local control and moderate radiation induced toxicity. Material and Methods The retrospective analysis contained 17 patients with esthesioneuroblastoma (Kadish stage ≥ C: 88%; n=15). 4

Conclusion EGFR as blood biomarker is an independent predictor for OS of patients with laryngeal carcinoma. OS curves for patients in high vs low EGFR group are visible in figure 1. Based on this small cohort the prognostic value of our existing nomogram was improved, but an independent cohort would be needed for external validation. Further research is needed to correlate EGFR blood values with EGFR expression in tumor samples.

References: 1. Egelmeer AGTM et al. Development and validation of a nomogram for prediction of survival and local control in laryngeal carcinoma patients treated with radiotherapy alone: A cohort study based on 994 patients. Radiother Oncol . 2011;100(1):108. 2. Ang KK et al. Impact of Epidermal Growth Factor Receptor Expression on Survival and Pattern of Relapse in Patients with Advanced Head and Neck Carcinoma. Canc Res. 2002;(713):7350. EP-1089 Prospective study of body composition changes during IMRT for H&N cancer as assessed by DXA scans J. Johansen 1 , A. Hermann 2 , S. Lønbro 3 1 Odense University Hospital, Oncology, Odense, Denmark 2 Odense University Hospital, Dept. of Endocrinology, Odense, Denmark 3 Aarhus University, Dept. of Public Health- Section for Sport Science, Aarhus, Denmark

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