ESTRO 2025 - Abstract Book

S1340

Clinical - Lung

ESTRO 2025

69 patients (out 360 planned) were recruited from 16 centres; 44 were randomised to a dose-intensified schedule. Demographics are presented in Table I. 66/69 completed planned radiotherapy. 12 experienced grade 3+ toxicity in the control arm, 19 in the dose-intensified schedules [1] . Median progression-free survival (95% CI) was 6.4 months (3.1, 9.7) in the control arm and ranged from 9.5 to 11.2 months in the dose-escalated arms. Median overall survival was 21.5 months (16.9, 41.1) in the control arm and ranged from 16.9 to 41.1 months in the dose-escalated arms. No statistical analyses were preformed due to inadequate sample size. Conclusion: ADSCaN closed early due to inadequate recruitment. All dose-intensified schedules were deliverable with no numerical increase in acute toxicity rates compared to the control arm of 55 / 20. Survival rates are around those expected for sequential chemo-radiotherapy but numbers are too small to permit comparisons between arms. References: 1. Hatton M, et.al: Continuous Hyperfractionated Accelerated RadioTherapy – Escalated Dose(CHART-ED): A Phase I study: Radio.Oncology 2016;118:471-77. 2. Landau DB et.al. IDEAL-CRT: A Phase 1/2 Trial of Isotoxic Dose-Escalated Radiation Therapy and Concurrent Chemotherapy in Patients with Stage II/III NSCLC. Int J Radiat Oncol Biol Phys 2016; 95:1367-1377 ISRCTN: 12155469 3. Lester JF et.al. Initial Results of the phase Ib/II, I-START trial - Isotoxic Accelerated Radiotherapy for treatment of Stage II-IIIB NSCLC. https://ascopubs.org/doi/10.1200/JCO.2018.36.15_suppl.e20551  4. Haslett K et.al Isotoxic Intensity Modulated Radiotherapy (IMRT) in stage III NSCLC: A feasibility study. Int.JRadiat.Oncol.Biol Phys2021:109;1341-8 Keywords: NSCLC, dose escalated radiotherapy