ESTRO 2024 - Abstract Book

S5289 ESTRO 2024 phenylalanine, L-isoleucine, proline-betaine) and stress-related hormones (cortisone, cortisol). Interestingly, no statistically significant alterations were observed in lipid metabolites. Radiobiology - Normal tissue radiobiology

Conclusion:

Our analysis of blood serum samples has shown a promising metabolic fingerprint linked to radiation exposure. The identification of five downregulated metabolites after radiotherapy, combined with a set of discriminative metabolites, underscores the potential of this metabolic approach. Validation of these results in other body fluids like urine and other patients’ cohorts is currently ongoing.

Keywords: Metabolomics, Biodosimetry

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Comparison of androgen deprivation therapy drugs in attenuating the RT-induced bladder toxicity

Riccardo Vago 1,2 , Federica Vurro 1 , Giorgia Colciago 1 , Giuseppe Fallara 3 , Stefania Zuppone 1 , Lisa Alborghetti 4 , Alberto Briganti 3,2 , Andrea Salonia 3,2 , Francesco Montorsi 3,2 , Nadia Di Muzio 5,2 , Antonello Spinelli 6 , Claudio Fiorino 4 , Cesare Cozzarini 5 1 IRCCS San Raffaele Scientific Institute, Urological Research Institute, Milano, Italy. 2 Università Vita-Salute San Raffaele, Faculty of Medicine and Surgery, Milano, Italy. 3 IRCCS San Raffaele Scientific Institute, Department of Urology, Milano, Italy. 4 IRCCS San Raffaele Scientific Institute, Department of Medical Physics, Milano, Italy. 5 IRCCS San Raffaele Scientific Institute, Department of Radiotherapy, Milano, Italy. 6 IRCCS San Raffaele Scientific Institute, Experimental Imaging Centre, Milano, Italy

Purpose/Objective:

Prostate cancer (PCa) is one of the most commonly diagnosed malignancy worldwide. Radiation therapy (RT) holds a primary role in PCa treatment, in combination with surgery or other therapies. A severe complication of RT due to partial irradiation of the bladder is represented by the actinic cystitis, a chronic inflammatory process leading to bladder dysfunction. Patients may experience reduced bladder capacity, impaired voiding function, incontinence, pain and urinary bleeding. A few exploratory pre-clinical studies have suggested anti-androgens drugs as potentially effective in reducing urinary toxicity. The current study is focused on the assessment of the potential role of the anti-androgen drugs Degarelix (Deg), Leuprorelin (Leu) and Triptorelin (Trp) at different doses to reduce urinary toxicity in an animal model.

Material/Methods:

We established a rat model resembling the main features of radiation-induced cystitis and followed its evolution over time by measuring the functional parameters through recordings of micturition pattern by cystometry and by investigating the structural alterations through immunohistochemistry. To test the effect of anti-androgen therapy of RT-induced bladder damage, we compared the effect of the gonadotropin-releasing hormone receptor (GnRHR) antagonist Deg and of the GnRHR agonists Leu and Trp. Two doses of each drug were defined to obtain