ESTRO 2024 - Abstract Book

S857

Clinical - CNS

ESTRO 2024

1699

Digital Poster

90 Y intra-arterial super-selective delivery for recurrent Glioblastoma: feasibility and safety

Giulia Paolani 1 , Silvia Minosse 2 , Silvia Strolin 1 , Miriam Santoro 1 , Noemi Pucci 3 , Francesca Di Giuliano 3 , Roberto Floris 3 , Francesco Garaci 3 , Letizia Oddo 4 , Yosra Toumia 4,5 , Eugenia Guida 3 , Susanna Dolci 3 , Francesco Riccitelli 4 , Gaio Paradossi 4,5 , Fabio Domenici 4,5 , Valerio Da Ros 3 , Lidia Strigari 1 1 IRCCS Azienda Ospedaliero-Universitaria di Bologna, Department of Medical Physics, Bologna, Italy. 2 Fondazione PTV Policlinico “Tor Vergata”, University of Rome “Tor Vergata”, Department of Integrated Care Processes, Rome, Italy. 3 University of Rome “Tor Vergata”, Department of Biomedicine and Prevention, Rome, Italy. 4 University of Rome “Tor Vergata”, Department of Chemical Science and Technologies, Rome, Italy. 5 National Institute for Nuclear Physics, INFN Roma Tor Vergata, Rome, Italy

Purpose/Objective:

In Glioblastoma (GBM) relapsing patients, re-intervention and second-line chemotherapy are ineffective and tumor re-irradiation needs higher doses leading to increased neurotoxicity. The development of alternative methods is needed. The feasibility and safety of Intra-arterial cerebral infusion(IACI) of Yttrium-90-Poly(vinyl alcohol)-Microbubbles(90Y PVA-MBs) in recurrent GBM patients from MRI 3D post-contrast T1-weighted images(MRI-3DT1-w) were investigated and compared to external beam radiation therapy approach.

Material/Methods:

MRI-3DT1-w were used to delineate tumor volumes and CT scans were used to automatically segment organs at risk in nine patients with recurrent GBM. Volumetric Modulated Arc Therapy(VMAT) treatment plans were generated using a clinical treatment planning system. Assuming the relative intensity of each voxel from the MRI-3DT1-w was a valid surrogate of post-IACI 90Y-PVA-MBs distribution, a specific 90Y dose-voxel-kernel was obtained with Monte Carlo simulations and convolved with the MRI, obtaining 90Y-PVA-MBs -based dose distribution then compared with VMAT plans.

Results:

The physical dose distribution obtained from the simulation of 1GBq of 90Y-PVA-MBs was rescaled to guarantee that the 95% of the prescribed dose was delivered to the 95% or the 99% of target (i.e., A95% and A99%, respectively). The calculated activities were A95%=269.2 [63.6-2334.1]MBq and A99%=370.6[93.8-3315.2]MBq, while the mean doses to the target were 58.2 [58.0-60.0]Gy for the VMAT, and 123.1[106.9-153.9]Gy, 170.1[145.9-223.8]Gy considering A95% and A99%,respectively. In addition, the non-target-brain tissue was spared in the 90Y-PVA-MBs