ESTRO 2024 - Abstract Book

S855

Clinical - CNS

ESTRO 2024

GK radiosurgery is a minimally invasive technique to treat TN, safe and effective. It is associated with a low risk of facial paresthesias and approximately half patients experienced pain relief.

Keywords: GammaKnife, trigeminal, neuralgia.

1691

Digital Poster

Clinical transfer of synchrotron microbeam radiation therapy: Canine brain tumor phase I study

Laura Eling 1 , Jean-François Adam 1 , Jacques Balosso 2 , Paul Berkvens 3 , Gilles Berruyer 3 , Thierry Brochard 3 , Gabriel Chamel 4 , Renaud Drevon-Gaud 5 , Andréa Desagneaux 2 , François Estève 1 , Isabelle Flandin 2 , Maxime Gaudin 6 , Yves Giraud 2 , Lucile Giraud 6 , Samy Kefs 2 , Sarvenaz Keshmiri 1 , Alexandre Krainik 2 , Michael Krisch 3 , Jean Laissue 7 , Gaëtan Lemaire 1 , Christian Nemoz 3 , Paolo Pellicioli 3 , Michel Renier 3 , Camille Verry 2 , Raphael Serduc 1 1 Univ. Grenoble Alpes. INSERM UA7 STROBE, Rue de la Piscine, 38400, Saint- Martin d’Hères, France. 2 Centre Hospitalier Universitaire Grenoble-Alpes, Maquis du Grésivaudan, 38700, La Tronche, France. 3 European Synchrotron Radiation Facility, Avenue des Martyrs, 38043, Grenoble, France. 4 Clinical Oncology Unit, Small Animal Internal Medicine Department, University of Lyon, VetAgro Sup Campus Vétérinaire, Avenue Bourgelat, 69280, Marcy l’Etoile, France. 5 ARGOS, Clinique Vétérinaire de l’Esplanade, Route de Lyon, 38000, Grenoble, France. 6 OnlyVet, Rue Jean Zay, 69800, Saint Priest, France. 7 University of Bern, 3000, Bern, Switzerland

Purpose/Objective:

The benefits of spatially-fractionated radiation therapy have been maximized through synchrotron Microbeam Radiation Therapy (MRT). MRT has repeatedly proven its superiority compared with conventional RT in increasing the therapeutic ratio of brain tumor treatment in preclinical research. In 2021 the clinical transfer phase of MRT has started: the first dog brain tumor patient was treated under clinical conditions to determine the safety and feasibility of MRT in view of the imminent clinical transfer. As a primary endpoint, the tolerance of normal brain tissues to MRT was evaluated, while the efficacy in reducing tumor volume was considered as a secondary endpoint.

Material/Methods:

The 6 year-old male French bulldog received a single-session of 3D-conformal, image-guided MRT for brain tumor treatment (suspected glioma). Ultra-high dose rate synchrotron x-rays, spatially fractionated into arrays of microbeams (50 µm-wide, 400 µm-spaced), were delivered through 5 conformal incidences. The PTV (CTV + 1 mm) received a minimal cumulated valley dose (diffusing between microbeams) of 2.8Gy, corresponding to ~25Gy peak dose (within microbeams) per incidence. The dog underwent monthly MRI, veterinary controls and owner evaluations.