Abstract Book

S140

ESTRO 37

OC-0276 Combining different genomic signatures to improve the prognostic power for LRC af ter PORT-C in HNSCC S. Schmidt 1,2,3,4 , A. Linge 1,2,4,5,6 , A. Zwanenburg 1,2,6,7 , S. Leger 1,2 , M. Großer 8 , F. Lohaus 1,2,5,6 , V. Gudziol 6,9 , A. Nowak 6,10 , I. Tinhofer 11,12 , V. Budach 11,12 , M. Stuschke 13,14 , P. Balermpas 15,16 , C. Rödel 15,16 , A.L. Grosu 17,18 , A. Abdollahi 19,20,21,22,23 , J. Debus 19,20,21,23,24 , C. Belka 25,26,27 , S.E. Combs 25,28,29 , D. Mönnich 30,31 , D. Zips 30,31 , G.B. Baretton 2,6,8,32 , F. Buchholz 2,33 , M. Baumann 1,2,3,5,6,7 , M. Krause 1,2,3,5,6 , S. Löck 1,2,5 1 OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus - Technische Universität Dresden - Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany 2 German Cancer Research Center DKFZ - Heidelberg - and German Cancer Consortium DKTK, partner site Dresden, Dresden, Germany 3 Institute of Radiooncology - OncoRay, Helmholtz- Zentrum Dresden – Rossendorf, Dresden, Germany 5 Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus - Technische Universität Dresden, Dresden, Germany 6 National Center for Tumor Diseases NCT, partner site Dresden, Dresden, Germany 7 German Cancer Research Center, DKFZ, Heidelberg, Germany 8 Institute of Pathology, Faculty of Medicine and University Hospital Carl Gustav Carus - Technische Universität Dresden, Dresden, Germany 9 Department of Otorhinolaryngology, Faculty of Medicine and University Hospital Carl Gustav Carus - Technische Universität Dresden, Dresden, Germany 10 Department of Oral and Maxillofacial Surgery, Faculty of Medicine and University Hospital Carl Gustav Carus - Technische Universität Dresden, Dresden, Germany 11 German Cancer Research Center DKFZ - Heidelberg - and German Cancer Consortium DKTK, partner site Berlin, Berlin, Germany 12 Department of Radiooncology and Radiotherapy, Charité University Medicine, Berlin, Germany 13 German Cancer Research Center DKFZ - Heidelberg - and German Cancer Consortium DKTK, partner site Essen, Essen, Germany 14 Department of Radiotherapy, Medical Faculty - University of Duisburg-Essen, Essen, Germany 15 German Cancer Research Center DKFZ - Heidelberg - and German Cancer Consortium DKTK, partner site Frankfurt, Frankfurt, Germany 16 Department of Radiotherapy and Oncology, Goethe- University Frankfurt, Frankfurt, Germany 17 German Cancer Research Center DKFZ - Heidelberg - and German Cancer Consortium DKTK, partner site Freiburg, Freiburg, Germany 18 Department of Radiation Oncology, Medical Center - Medical Faculty - University of Freiburg, Freiburg, Germany 19 German Cancer Research Center DKFZ - Heidelberg - and German Cancer Consortium DKTK, partner site Heidelberg, Heidelberg, Germany 20 Heidelberg Ion Therapy Center HIT - Department of Radiation Oncology, University of Heidelberg Medical School, Heidelberg, Germany 21 National Center for Tumor Diseases NCT, University of Heidelberg Medical School and German Cancer Research Center DKFZ, Heidelberg, Germany 22 Translational Radiation Oncology, University of Heidelberg Medical School and German Cancer Research Center DKFZ, Heidelberg, Germany 23 Heidelberg Institute of Radiation Oncology HIRO - National Center for Radiation Research in Oncology NCRO, University of Heidelberg Medical School and German Cancer Research Center DKFZ, Heidelberg,

For all endpoints scored during and after treatment, similar toxicity patterns were observed: there was a marked increase during treatment, reaching a maximum at the end of treatment, followed by a gradual recovery starting in de first 6 months after treatment with almost no further recovery beyond 24 months. Weight loss showed a similar pattern, however the maximum loss was reached at 6 months after treatment. For late toxicities, including skin fibrosis, hypothyroidism and late mucosal toxicity, a gradual increase in prevalence was seen over time (fig. 1). In the four different subgroups, more or less similar toxicity patterns were observed, however with different severities, as shown for dysphagia in figure 2. The percentage of patients recovering, derived from the individual toxicity patterns, differed between toxicity endpoints. For endpoints that showed a general trend of recovery, the highest recovery was seen for sore throat (99%) and oral pain (95%), while the lowest recovery was seen for xerostomia (73%), aspiration (54%) and weight loss (39%).

Conclusion This is the largest prospective population-based cohort study providing comprehensive toxicity risk (CITOR) profiles in HNC patients treated with definitive radiotherapy with or without systemic treatment. These CITOR profiles can be produced for numerous patient-, tumor- and treatment-related subgroups, serving as a toxicity benchmark of the current treatment, allowing comparison with new treatment approaches. When combined with NTCP-models, predicted CITOR profiles enable a comprehensive assessment of the potential benefit of new radiation technologies.