ESTRO 2025 - Abstract Book

S3983

Radiobiology - Tumour radiobiology

ESTRO 2025

Conclusion: 3D printing technology enables the creation of highly precise MBRT collimators and offers substantial improvements in radiotherapy treatment. By inducing vascular normalization and optimizing tumor perfusion, MBRT shows promise as a novel strategy for enhancing therapeutic outcomes, particularly in challenging cancers like TNBC.

Keywords: Minibeam radiation therapy

1888

Digital Poster Suppression of radiation-induced migration of non-small cell lung cancer with Microbeam Radiation Therapy (MRT) Marina Santiago Franco 1,2 , Ömer Dağkazanlı 1,2 , Aleksandra Čolić 1,2 , Rainer Lindner 2 , Stephanie E. Combs 1,2,3 , Stefan Bartzsch 1,2 , Thomas E. Schmid 1,2 1 Department of Radiation Oncology, Technical University of Munich, Munich, Germany. 2 Institute of Radiation Medicine, Helmholtz Munich, Munich, Germany. 3 Partner Site Munich, Deutsches Konsortium für Translationale Krebsforschung, Munich, Germany Purpose/Objective: Most patients with lung cancer (LC) will present metastatic disease. It has been demonstrated that irradiation plays a critical role in LC cell migration, the first step of the metastatic cascade. This highlights the need for alternative treatments and better understanding of the mechanisms behind motility modulation 1 . Microbeam Radiation Therapy (MRT) uses spatial fractionation of radiotherapy into beams with a micrometer range. It has been demonstrated as a promising tool for the treatment of LC with high efficacy and a potential to spare the healthy tissue 2 . Our research aims to investigate the impact of MRT on LC cell motility. Material/Methods: A549 cells (a human non-small cell LC cell line) had its 2D and 3D migration ability investigated after broad beam irradiation (BB) and MRT. BB was performed on a RS225 irradiator while MRT was performed on a XenX irradiator, both from X-Strahl, modified with a self-developed collimator. 2D migration was investigated using 2-well inserts and 3D migration with transwell inserts (8.0 µm pore membrane). The adhesion properties of A549 and gene expression changes (TGFb, NFkB, ITGAV, MMP2, MMP9) were investigated (RTqPCR) after BB. We also investigated how BB irradiation of MRC-5 (normal human lung fibroblasts) impacted the 3D migration of A549 cells on a co culture assay. BB doses were sham, 2, 4 and 6 Gy while MRT were the equivalent uniform doses (EUD).