ESTRO 2023 - Abstract Book

S938

Digital Posters

ESTRO 2023

Figure 2 ImageJ delineation of the paravertebral and sternocleidomastoid muscles at the level of the third cervical vertebra (C3) (threshold setting: -29 to +150 HU) in a sarcopenic patient. Results One hundred and sixteen patients were included in the study. Most of them had locally advanced (95.7%) and HPV-associated carcinomas (74.1%) and were treated with concurrent chemotherapy (90.5%). Based on MM-CSA, becoming sarcopenic during RT (16 patients) was associated with worse PFS (HR 2.52, 95% CI 1.09-5.83, p = 0.03) on multivariate analysis and a trend of correlation with OS was evident too (HR 2.69, 95% CI 0.99-7.28, p = 0.05). Based on C3-CSA, becoming sarcopenic during RT (14 patients) was associated with worse PFS (p = 0.0096) and OS (p = 0.013) on univariate analysis; these correlations were not confirmed on multivariate analysis. Based on both MM-CSA and C3-CSA, no statistically significant associations were found between sarcopenia and worse RT toxicity. Based on C3-CSA, a statistically significant association was present between becoming sarcopenic during RT and reduced baseline haemoglobin values (p = 0.03) and the activation of nutritional counselling during RT (p = 0.02). Conclusion Our data suggest that early identification of sarcopenia during RT could bring additional information to aid clinical decision making i.e., the activation of a prompt nutritional intervention to improve oncological outcomes. Further research with prospective trials, especially in HPV-associated oropharyngeal carcinoma, is needed to identify valid biomarkers and better include sarcopenia in a tailored approach to these patients with long life expectancy, involving, for example, the implementation of more sophisticated technologies, such as proton-therapy. 1 Kantonsspital Winterthur, Department of Radiation Oncology, Winterthur, Switzerland; 2 Ruppiner Kliniken GmbH, Department of Radiation Oncology, Neuruppin, Germany Purpose or Objective To evaluate clinical outcome and toxicity in patients treated with re-irradiation (re-RT) for loco-regionally recurrent or second primary head and neck cancer (LRR/SP HNC) at a single institution. Materials and Methods Retrospective analysis of 63 LRR/SP HNC patients who underwent definitive or postoperative twice daily hyperfractionated (chemo)-re-RT between 2001 and 2022. Overall survival (OS), progression-free survival (PFS), locoregional control (LRC) and distant metastasis control (DMC) were analyzed and prognostic factors were evaluated. Acute and late toxicity were prospectively collected. Results The median follow-up was 8.6 months. Two-year OS, PFS and LRC were 20%, 19% and 31%, respectively. Multivariate analysis revealed recurrent T stage 0-3, chemotherapy and re-RT dose of 60 Gy as significant favorable factors for OS (all p < 0.005). In addition to these factors, recurrent N stage 0-1, overall stage I-III and a longer disease-free interval (>24 months) were significantly associated with improved PFS (all p < 0.005). All these factors, except re-RT dose, were significantly associated with better LRC. At least one new grade ≥ 3 acute toxicity was observed in 37 patients (69%) comprising mostly dysphagia and/or mucositis. Late toxicity included grade ≥ 3 dysphagia in 7.1% of evaluable patients and osteoradionecrosis in 9.5%. PO-1173 Re-irradiation in H&N cancer: A retrospective outcome analysis using a single institutional database D. Zwahlen 1 , C. Scolari 1 , C. Schröder 1 , R. Förster 1 , A. Buchali 2

Conclusion The use of re-RT may be a curative treatment option with acceptable toxicity only for well-selected patients.