ESTRO 2024 - Abstract Book

S5251 ESTRO 2024 These results suggest the combinatory therapy of US-induced BBB opening and FLASH radiation is safe and feasible in vivo. More investigation is needed for longer-term neurological effects, but the risk-to-benefit ratio will be low. Studies on the orthotopic brain tumour models are currently underway. Radiobiology - Normal tissue radiobiology

Keywords: ultrasound, drug delivery, FLASH radiotherapy

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Digital Poster

Protective effects of grape seed extract on radiation-induced mucositis: a pre-clinical study

Gabriele D'Ercole 1 , Michele Fiore 1,2 , Elena Imperia 3 , Annamaria Altomare 4,2 , Roberta Maria Nicolosi 4 , Ludovica Spagnuolo 4 , Laura Dugo 4 , Laura De Gara 4 , Gabriella Pasqua 5 , Michel Cicala 3,2 , Michele Pier Luca Guarino 3,6 , Sara Ramella 1,7 1 Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Research unit of Radiation Oncology, Roma, Italy. 2 Fondazione Policlinico Campus Bio-Medico di Roma, Unit of Gastroenterology, Roma, Italy. 3 Università Campus Bio-Medico di Roma, Research unit of gastroenterology, Roma, Italy. 4 Università Campus Bio Medico di Roma, Food Sciences and Human Nutrition Unit, Roma, Italy. 5 Department of Environmental Biology, Sapienza Università di Roma, Roma, Italy. 6 Università Campus Bio-Medico di Roma, Unit of Gastroenterology, Roma, Italy. 7 Fondazione Policlinico Campus Bio-Medico di Roma, Research unit of Radiation Oncology, Roma, Italy

Purpose/Objective:

The study investigated the efficacy of grape seed extract (GSE), derived from grape pomace, as a protective agent against mucosal stress caused by ionizing radiation and bacterial infections.

Material/Methods:

GSE was analyzed using high-performance liquid chromatography (HPLC-DAD) and nuclear magnetic resonance (NMR). 6-well plates containing inserts with human intestinal epithelial cells (Caco-2) treated with lipopolysaccharide (LPS), GSE or LPS+GSE, were irradiated with a flat and symmetric (± 2%) 40x40 cm2 X-Rays radiation field and a dose rate of 3Gy/min at a room temperature. Cells were irradiated with 2 Gy per day up to a maximum of 10 Gy. The analysis of the irradiated material was performed at the total doses of 0 Gy (control condition, sham), 2, 4, 6, 8, and 10 Gy. Every sham sample underwent the same enviromental and mechanical stress, except for the radiation exposure. Epithelial barrier integrity was assessed using fluorescein isothiocyanate-dextran, ROS production was measured by adding 2′,7′-dichlorodihydrofluorescein diacetate using a Tecan reader. Experiments were performed twice in triplicates.

Results:

HPLC-DAD and NMR revealed that GSE contained 70% of procyanidins and 24 other metabolites. Co-treatment with GSE prevented epithelial barrier damage in LPS-treated cells (5.215 vs 0.3407; p<0.05). Irradiation increased intestinal permeability in both Caco-2 cells without LPS treatment (3.64 vs 0.441; p<0.05) and LPS-treated cells (25.5 vs 2.42; p<0.05), while GSE treatment significantly reduced this damage in both conditions (25.5 vs 2.04;