ESTRO 2022 - Abstract Book

S427

Abstract book

ESTRO 2022

Conclusion A significant deleterious inter-observer variability appears for GTV delineations, which can be explained by differences in interpretation of the endoscopy, level of experience, or working practice proper to each institution. An improved agreement was found after consensus as discussions acted as a sanity check and showed benefit for clinical routine. This study reinforces the need for multimodality when dealing with target volume definition, like multiparametric functional imaging or biopsies. Moreover, the development of artificial intelligence solutions for standardization and treatment automation could also be of great help.

MO-0477 Pretherapeutic sarcopenia predicts survival of elderly patients undergoing radiation for HNSCC

E. Haehl 1,3 , L. Alvino 2 , A. Rühle 2 , A. Fabian 2 , J. Zou 2 , S. Spohn 2 , C. Zamboglou 2 , E. Gkika 2 , A. Grosu 2 , N. Nicolay 2

1 University of Freiburg - Medical Center, Department of Radiation Oncology, Freiburg, Germany; 2 University of Freiburg Medical Center, Department of Radiation Oncology, Freiburg, Germany; 3 University of Munich, Department of Radiation Oncology, Munich, Germany Purpose or Objective Sarcopenia is associated with reduced survival and increased vulnerability to toxicity in malignant diseases including squamous cell carcinoma of the head and neck (HNSCC). The prevalence of sarcopenia increases with age and is an important cause of functional decline in the elderly. We evaluated the influence of pre- and posttherapeutic sarcopenia in elderly (>65 years) HNSCC patients undergoing (chemo-)radiation regarding oncologic outcome and therapy-related toxicity. Materials and Methods 280 elderly patients receiving radiotherapy or chemoradiation for HNSCC at the University of Freiburg Medical Center were included in this analysis. Pretherapeutic and posttherapeutic CT-scans of the head & neck region were available for 280 and 109 patients, respectively. Skeletal muscle area as an indicator for sarcopenia was outlined and quantified at the level of the third cervical vertebra (C3MA) in all CT scans. Using a previously published formula, C3MA was converted to the cross-sectional muscle area at the third lumbal vertebra (L3MA) and normalized for height (L3MI). After sex-specific standardization, pretherapeutic muscle indices were correlated with clinical parameters. After dichotomous categorization into “sarcopenic” and “non-sarcopenic” based on established cut-off values, the influence of pre- and posttherapeutic sarcopenia on overall-survival (OS), progression-free-survival (PFS) and treatment-related toxicity was calculated. Results L3MA correlated significantly with pretherapeutic hemoglobin levels ( p <0.01), pretherapeutic weight ( p <0.01), and inversely with patient age ( p <0.01). Patients classified as sarcopenic showed significantly larger tumors (T3/4 52.8% vs 69.0%, p <0.01) and a higher burden of comorbidity (CCI 4.8 vs 4.2, p =0.015) and experienced significantly higher chronic toxicities (CTCAE grade 3/4 24.0% vs 11.8%, p= 0.022). OS and PFS were significantly deteriorated in sarcopenic patients with a median of 91 vs 23 month ( p =0.002) and 47 vs 12 month ( p <0.01), respectively. In the multivariate analysis taking