ESTRO 2024 - Abstract Book

S5315

Radiobiology - Tumour biology

ESTRO 2024

effect. In any case, we consider that chemoradiotherapy combined with radiation and EGFR inhibitors can be an effective treatment for triple-negative breast cancer.

Keywords: breast cancer, triple negative type

References:

1)Blows FM, Driver KE, Schmidt MK, et al. Subtyping of breast cancer by immunohistochemistry to investigate a relationship between subtype and short and long term survival: a collaborative analysis of data for 10,159 cases from 12 studies. PLoS Medicine 2010;7:e1000279.

2)Li J, Chen Z, Su K, Zeng J. Clinicopathological classification and traditional prognostic indicators of breast cancer:Int J Clin Exp Pathol. 2015;8(7):8500-5.

3)Rakha EA, Reis-Filho JS, Ellis IO. Basal-like breast cancer: a critical review. J Clin Oncol. 2008;26(15):2568-81.

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Digital Poster

The predictive value of Equivalent Uniform Dose (EUD) in Microbeam Radiation Therapy (MRT)

Thomas E Schmid 1,2 , Robert D Stewart 3 , Mabroor Ahmed 2 , Sandra Bicher 2 , Stephanie E Combs 1 , Stefan Bartzsch 1 , Juergen Meyer 3 1 Klinikum rechts der Isar, Department of Radiooncology, Muenchen, Germany. 2 Helmholtz Zentrum Muenchen GmbH, Institute of Radiation Medicine, Neuherberg, Germany. 3 Fred Hutchinson Cancer Center, Department of Radiation Oncology, University of Washington, Seattle, USA

Purpose/Objective:

Spatially Fractionated Radiation Therapy (SFRT) is characterized by large differences in peak and valley doses. The two innovative SFRT techniques, Microbeam, Irradiation Therapy (MRT) and Minibeam Irradiation Therapy (MBRT) have the potential to increase the therapeutic window for selected cancers and treatment modalities. Biologically relevant dose-metrics are needed to properly evaluate and compare the results of laboratory experiments with different MRT and MBRT parameters. They are also needed to translate and design relevant clinical trials comparing MRT and MBRT to more conventional treatment modalities. Therefore, the aim of this work is to test the hypothesis that EUD is a superior predictor of in vitro cell survival for SFRT average or valley dose when compared to uniform irradiation of cell cultures.

Material/Methods: