ESTRO 2025 - Abstract Book

S1460

Clinical – Mixed sites & palliation

ESTRO 2025

Results: 20 patients with histologically proven bulky sarcoma were treated with PABR technique at our institution from Jan 2020 to Mar-2024. The centrally located volume exceeding 50Gy effectively achieved high biological effective dose close to 100Gy 4 , which resulted in the desired outcomes of symptom relief (for the entire patient cohort) and tumour size reduction (90% of the patient cohort) with a mean absolute tumour volume reduction of 50%. Dose gradient of 3Gy/mm (20Gy to 50Gy in 1cm space) is effectively achievable in 5 fraction regime utilsing 10MVFFF beam and VMAT technique without increasing dose-spillage compared to the standard palliative regime. This novel treatment technique has been protocolised for the upcoming prospective clinical trial within our institution.