ESTRO 2024 - Abstract Book

S3608

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

ESTRO 2024

parameters for all volume categories, implying that VMAT is less sensitive to shape variances of the lesion compared to DCA concerning the investigated dosimetric properties.

Conclusion:

Both DCA and VMAT are established MLC-based radiation techniques in SRS. Departments offering Linac-based SRS typically have access to both treatment modalities. However, a decision-support tool for selecting the appropriate modality is currently the focus of our research. We examined various parameters, including roundness, sphericity, and Q asym , to determine the asymmetry of lesions. Significant correlations were found in DCA between Q asym and various dosimetric parameters for treatment plan evaluation. For volumes <2cm³, Q asym was particularly sensitive, while roundness and sphericity showed no significant correlations. Our goal was to propose an easily applicable tool based on existing data such as lesion volume and maximum diameter. This simplifies the calculation of Qasymmetry in clinical practice without the need for external software. Furthermore, we discovered that this parameter exhibited the best sensitivity for smaller volumes.

Keywords: Radiosurgery, Asymmetry, SRS

References:

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