S674
Clinical – Head & neck
ESTRO 2026
biopsy). Covariates included treatment intent (adjuvant vs definitive), concurrent chemotherapy, tumour site, and distance to centre. Continuous variables were summarised as median (IQR); categorical data as percentages. Univariate comparisons used Mann–Whitney U and χ² tests. Multivariable logistic regression identified independent predictors of delay; results are reported as odds ratios (OR) with 95% confidence intervals (CI). Analyses were performed in IBM SPSS Statistics version 23 (IBM Corp., Armonk, NY, USA). The audit was conducted under institutional QA oversight; all data were anonymised, and ethics approval was waived. Results: Median time from diagnosis to RT start was 87.5 days (IQR 42.5); only 11% of patients initiated RT ≤ 60 days. Adjuvant RT patients had longer intervals than definitive RT (94 vs 77 days; p=0.073). In multivariable analysis, adjuvant RT (OR ≈ 2.6; 95%CI 0.9–7.4; p=0.08) and distance >50 km (OR ≈ 2.1; 95%CI 0.8–5.5; p=0.11) showed trends toward higher odds of delay, whereas concurrent chemotherapy and tumour site were not significant. Model discrimination was fair (AUC=0.71). Counterfactual modelling suggested that a 10-day reduction in the longest intervals (biopsy → MDT and simulation → RT start) could improve on-time initiation from 11% to 24%. Conclusion: Postoperative intent and patient distance from centre are key determinants of radiotherapy delay in HNC. Quantifying these predictors enables targeted interventions—such as fast-track postoperative MDT scheduling and decentralised simulation access—to improve equity and timeliness. These findings define actionable benchmarks for integration into departmental and ESTRO quality frameworks, such as QUATRO and IAEA QUANUM. References: 1. Graboyes EM, Kompelli AR, Neskey DM, Brennan E, Nguyen S, Sterba KR, Warren GW, Hughes-Halbert C, Nussenbaum B, Day TA. Association of Treatment Delays With Survival for Patients With Head and Neck Cancer: A Systematic Review. JAMA Otolaryngol Head Neck Surg. 2019 Feb 1;145(2):166-177. doi: 10.1001/jamaoto.2018.2716. PMID: 30383146; PMCID: PMC6494704.2. Murphy CT, Galloway TJ, Handorf EA, Egleston BL, Wang LS, Mehra R, Flieder DB, Ridge JA. Survival Impact of Increasing Time to Treatment Initiation for Patients With Head and Neck Cancer in the United States. J Clin Oncol. 2016 Jan 10;34(2):169- 78. doi: 10.1200/JCO.2015.61.5906. Epub 2015 Nov 30. PMID: 26628469; PMCID: PMC4858932. Keywords: HNC, RT delay, quality benchmark
Conclusion: The GARD stratification has a limited prognostic value for locoregional failure in Danish HNSCC patients. References: 1.Scott JG, Berglund A, Schell MJ, et al. A genome- based model for adjusting radiotherapy dose (GARD): a retrospective, cohort-based study. Lancet Oncol. 2017;18(2):202-11.2.Eriksen JG, Maare C, Johansen J, et al. DAHANCA 19: A Randomized Phase III Study of Primary Curative (Chemo)-Radiotherapy and the EGFR- Inhibitor Zalutumumab for Squamous Cell Carcinoma of the Head and Neck. Radiotherapy and Oncology. 2025; 208:1108993.Eschrich S, Zhang H, Zhao H, et al. Systems Biology Modeling of the Radiation Sensitivity Network: A Biomarker Discovery Platform. INT J Radiat Oncol Biol Phys. 2009;75(2):497-505. Keywords: GARD, Radiosensitivity, HNSCC Digital Poster 5177 Predictors of delayed radiotherapy initiation in head and neck cancer: a real-world quality benchmark analysis Milos Grujic 1,2 , Sladjana Acimovic Talijan 2 , Ivana Tomic 2 , Marija Zivkovic Radojevic 1,2 , Katarina Krasic 2 , Katarina Jankovic 2 , Neda Milosavljevic 1,2 1 Department of Clinical Oncology, Faculty of Medical Sciences, Kragujevac, Serbia. 2 Center for Radiation Oncology, University Clinical Center Kragujevac, Kragujevac, Serbia Purpose/Objective: Treatment delays reduce survival in head and neck cancer (HNC), yet few real-world datasets quantify predictors of untimely radiotherapy (RT) [1,2]. This study aimed to identify clinical and system-level factors associated with delayed RT initiation (>60 days from diagnosis) and define benchmarks for departmental quality-improvement planning. Material/Methods: Eighty-two consecutive head and neck cancer patients treated with curative-intent radiotherapy between January 2023 and June 2025 were retrospectively analysed. Key timestamps—biopsy (diagnosis), multidisciplinary team (MDT) discussion, CT simulation, RT start and RT end—were extracted. The primary outcome was delayed RT start (>60 days from
Made with FlippingBook - Share PDF online