ESTRO 2025 - Abstract Book

S1501

Clinical – Mixed sites & palliation

ESTRO 2025

Material/Methods: Conducted at the National Institute of Cancer Research and Hospital, Bangladesh, from July 1, 2020, to June 30, 2021, this prospective, non-randomized study enrolled 90 patients aged 18 to 75 years with histologically confirmed primary malignancies and vertebral metastases. Patients were allocated to one of three treatment arms: 8 Gray in a single fraction (Arm A), 20 Gray in 5 fractions (Arm B), or 30 Gray in 10 fractions (Arm C). The primary endpoint was pain response at 12 weeks, assessed by the Visual Analogue Scale and International Bone Metastases Consensus. Secondary endpoints included toxicity, measured by the Common Terminology Criteria for Adverse Events, and overall survival. Results: Pain control at 12 weeks showed no significant differences among the treatment groups, with 70% of patients in Arm A, 67% in Arm B, and 70% in Arm C experiencing either partial or complete pain relief (p=0.95). The overall survival rates were comparable across the groups (median survival: 7 months for Arms A and C, 6 months for Arm B). Skin toxicity was significantly lower in Arm A (10% incidence) compared to Arms B (30%) and C (47%) (p=0.017). There were no reports of Grade-3 or higher toxicities, confirming the safety of the single fraction regimen.

Table 1: Pain response rates across different treatment arms

Conclusion: The study confirms the efficacy and safety of single fraction radiotherapy for spinal bone metastases, providing significant pain relief and lower skin toxicity relative to multiple fraction regimens. These results endorse single fraction radiotherapy as a viable and effective treatment option for managing vertebral metastases in resource limited settings, advocating its broader adoption to improve patient outcomes and reduce treatment burdens in low-middle-income countries.

Keywords: Single Fraction, Radiotherapy, Bone Metastases

1956

Digital Poster Reasons of discontinuation of radiotherapy during 2020-2023: a single-institution review Javier González-Viguera, Míriam Núñez, Joel Martínez, Ferran Ferrer, Miquel Macià, Ferran Guedea Radiation Oncology Department, Catalan Institute of Oncology, L’Hospitalet de Llobregat, Spain

Purpose/Objective: To investigate causes of definitive interruption of radiotherapy at our institution during 2020-2023.

Material/Methods: Database of our department was checked in April 2024. Files with discrepancy between prescribed and delivered dose were reviewed. Results: Among 12,742 radiotherapy treatments identified, 226 were discontinued prematurely (1.8%). The mean age was 66 years and in at least 70% of them the Karnofsky performance status was ≥ 70. Most common tumour sites were