ESTRO 2024 - Abstract Book

S3669

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2024

[2] Niemierko, Andrzej. A generalized concept of equivalent uniform dose (EUD). Med Phys 1999;26:1100.

[3] Mylona E, Cicchetti A, Rancati T, Palorini F, Fiorino C, Supiot S, et al. Local dose analysis to predict acute and late urinary toxicities after prostate cancer radiotherapy: Assessment of cohort and method effects. Radiother Oncol J Eur Soc Ther Radiol Oncol 2020;147:40–9. https://doi.org/10.1016/j.radonc.2020.02.028. [4] Dréan G, Acosta O, Ospina JD, Fargeas A, Lafond C, Corrégé G, et al. Identification of a rectal subregion highly predictive of rectal bleeding in prostate cancer IMRT. Radiother Oncol J Eur Soc Ther Radiol Oncol 2016;119:388–97. https://doi.org/10.1016/j.radonc.2016.04.023. [5] Rancati T, Eliana G, Massi M, Franco NR, Avuzzi B, Cicchetti A, et al. OC-0510 Genetically-based Cox-NTCP models for late toxicity after prostate cancer RT. Radiother Oncol 2023;182:S418–20. https://doi.org/10.1016/S0167-8140(23)08642-5.

2421

Digital Poster

Model-based VMAT optimization: The future of radiosurgery for multiple brain metastases?

Manuel Todorovic, Maximilian Grohmann, Cordula Petersen

University Medical center Hamburg-Eppendorf, Department of Radiotherapy and Radiation Oncology, Hamburg, Germany

Purpose/Objective:

The combined use of Model-Based Optimization and Stereotactic Radiosurgery (SRS) represents a promising frontier in brain tumor management, offering individualized and precise treatment options with reduced side effects. These innovative approaches continue to evolve, optimizing patient care, and improving outcomes for individuals facing brain tumors. The aim of this work is to identify situations in which a volumetric intensity modulated arc therapy (VMAT) approach offers advantages over a dynamic conformal arc (DCA) approach and to create a prediction model from this. The ultimate goal of this preliminary work is model-based VMAT optimization.

Material/Methods:

For 80 patients previously treated with SRS (336 irradiated metastases in total), both a DCA and a VMAT plan were retrospectively automatically generated using a new prototype version of the treatment planning system Elements (Brainlab AG, Munich, Germany).

All plans were created using the same set of planning parameters (e.g. 24 Gy prescribed dose with 32 Gy maximum, target coverage of 99%, 4 table angles).

The aim was to identify parameters where the VMAT approach yields better dosimetric outcome than the DCA approach. In a subsequent step, correlations between different parameters were determined.