ESTRO 2024 - Abstract Book

S787

Clinical - CNS

ESTRO 2024

progression from nadir’ seems to be the best approach. An external validation performing discrimination and calibration of the data as well as increasing the population size would be desirable.

Keywords: Radionecrosis, NTCP model, brain metastases

References:

1. Milano MT, Grimm J, Niemierko A et al. Single- and Multifraction Stereotactic Radiosurgery Dose/Volume Tolerances of the Brain. Int J Radiat Oncol Biol Phys. 2021 May 1;110(1):68-86. doi:10.1016/j.ijrobp.2020.08.013. Epub 2020 Sep 11.

2. Lin NU, Lee EQ, Aoyama H et al. Response assessment criteria for brain metastases: proposal from the RANO group. Review Lancet Oncol. 2015 Jun;16(6):e270-8. doi:10.1016./S1470-2045(15)70057-4. Epub 2015 May 27.

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Hyperoxygenation and re-irradiation for recurrent high grade glioma: innovative therapeutic strategy

Donatella Arpa 1 , Elisabetta Parisi 1 , Giulia Ghigi 1 , Lucia Fabbri 2 , Flavia Foca 3 , Patrizia Cenni 4 , Pasquale Longobardi 5 , Monica Celli 6 , Luca Tontini 1 , Elisa Neri 1 , Martina Pieri 1 , Simona Cima 1 , simona Micheletti 1 , Romeo Naim Abousiam 1 , Valerio Tonelli 7 , Elena Amadori 8 , Anna Tesei 9 , Antonino Romeo 1 1 , IRCCS Romagna Institute for the Study of Tumors "Dino Amadori" - IRST, Radiotherapy Unit, Meldola, Italy. 2 , IRCCS Romagna Institute for the Study of Tumors "Dino Amadori" - IRST, Biostatistics and Clinical Trials Unit otherapy Unit, Meldola, Italy. 3 , IRCCS Romagna Institute for the Study of Tumors "Dino Amadori" - IRST, Biostatistics and Clinical Trials Unit adiotherapy Unit, Meldola, Italy. 4 , IRCCS Romagna Institute for the Study of Tumors "Dino Amadori" - IRST, Neuroradiology Unit, Meldola, Italy. 5 Centro Iperbarico,, Centro Iperbarico,, Ravenna, Italy. 6 , IRCCS Romagna Institute for the Study of Tumors "Dino Amadori" - IRST, Unit of Nuclear Medicine, Meldola, Italy. 7 Oncological Institute of Veneto, Radiotherapy Unit, Padova, Italy. 8 , IRCCS Romagna Institute for the Study of Tumors "Dino Amadori" - IRST, Radiology unity, Meldola, Italy. 9 , IRCCS Romagna Institute for the Study of Tumors "Dino Amadori" - IRST, Biosciences Laboratory, Meldola, Italy High-grade gliomas (HGGs) represent the most malignant and most frequently encountered primary brain tumour in clinical neuro-oncology. Brain tumours, especially highly aggressive GBM with its necrotic tissue, are more likely to be affected by hypoxia. The median partial pressure of oxygen (PO2) of high-grade gliomas in patients under anaesthesia was approximately 5-7 mmHg, with a significant proportion of PO2 values <2.5 mmHg. The radiosensitivity of brain tumors could potentially be increased by performing hyperbaric oxygenation (HBO) before the RT session. We Purpose/Objective: