ESTRO 2024 - Abstract Book

S5364

Radiobiology - Tumour biology

ESTRO 2024

recruitment proceeds) with the addition of a paired 12-month biopsy for comparison with longitudinal SRUS and DCE/DW-MRI results.

Keywords: breast, microvasculature, transcriptomics

References:

1. Nimalasena, S. et al. Intratumoral Hydrogen Peroxide With Radiation Therapy in Locally Advanced Breast Cancer: Results From a Phase 1 Clinical Trial. International Journal of Radiation Oncology*Biology*Physics 108, 1019–1029 (2020).

2. Christensen-Jeffries, K. et al. Super-resolution Ultrasound Imaging. Ultrasound Med. Biol. 46, 865–891 (2020).

3. Aran, D., Hu, Z. & Butte, A. J. xCell: digitally portraying the tissue cellular heterogeneity landscape. Genome Biol. 18, (2017).

4. Partridge, S. C. et al. Diffusion-weighted MRI findings predict pathologic response in neoadjuvant treatment of breast cancer: The ACRIN 6698 multicenter trial. Radiology 289, 618–627 (2018).

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Digital Poster

High-fat diet promotes radiation resistance in rectal cancer through gut microbiota and metabolites

Jia Yang, Lihong Liu, Qichun Wei

The Second Affiliated Hospital, Zhejiang University School of Medicine, Department of Radiation Oncology, Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, National Ministry of Education), Hangzhou, China

Purpose/Objective:

It is known that dietary fat could promote colorectal cancer development. However, the effect of dietary fat on the efficacy of radiotherapy (RT) has not been investigated. Here, we examined the role of high-fat diet (HFD) in promoting radiation resistance in rectal cancer through modulating gut microbiota and metabolites.

Material/Methods:

HFD or control diet was fed to mice bearing orthotopically implanted rectal tumor with or without antibiotics cocktail treatment. RT was delivered to the rectal tumor by a total dose of 24Gy in 3 fractions. Fecal microbiota transplantation was performed to the antibiotics-induced gut microbiome-depleted mice for validation. Shotgun metagenomic sequencing and high-performance liquid chromatography-mass spectrometry were parallelly performed to