ESTRO 2025 - Abstract Book

S1354

Clinical - Lung

ESTRO 2025

In lung Stereotactic Body Radiation Therapy (SBRT), precise dose delivery to the Gross Tumour Volume (GTV) is crucial. As per ICRU recommendations, the dose is commonly prescribed to the planning target volume (PTV). However, this approach can lead to significant variability in the dose delivered to the GTV, particularly in non homogeneous tissue like lung. This study investigates dose distribution heterogeneity within the GTV in lung SBRT plans with the dose prescribed to the PTV. Material/Methods: Radiotherapy data including patient's CT scans, radiotherapy plan, dose distribution, structure dataset, and case submission forms were collected from lung SBRT patients from four EORTC studies: 22113 LungTech, 1945 OligoRare, 1702 Halt, and observational cohort 1822 OligoCare of the 1811 E2RADIatE study. Extracted parameters included prescribed PTV dose, mean GTV dose, dose calculation algorithm, and target location. The relative percentage difference between the prescribed dose and mean GTV dose was assessed to account for variations in fractionation schedules.

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