Toward Neuro-Oncologic Clinical Trials of High-Dose-Rate Synchrotron Microbeam Radiation Therapy: First Treatment of a Spontaneous Canine Brain Tumor.
Int J Radiat Oncol Biol Phys
; 113(5): 967-973, 2022 08 01.
Article
em En
| MEDLINE
| ID: mdl-35483539
ABSTRACT
PURPOSE:
The high potential of microbeam radiation therapy (MRT) in improving tumor control while reducing side effects has been shown by numerous preclinical studies. MRT offers a widened therapeutic window by using the periodical spatial fractionation of synchrotron generated x-rays into an array of intense parallel microbeams. MRT now enters a clinical transfer phase. As proof of principle and cornerstone for the safe clinical transfer of MRT, we conducted a "first in dog" trial under clinical conditions. In this report, we evaluated whether a 3-dimensional conformal MRT can be safely delivered as exclusive radiosurgical treatment in animal patients METHODS AND MATERIALS We irradiated a 17.5-kg French bulldog for a spontaneous brain tumor (glioma suspected on magnetic resonance imaging) with conformal high-dose-rate microbeam arrays (50-µm-wide microbeams, replicated with a pitch of 400 µm) of synchrotron-generated x-rays. The dose prescription adjusted a minimal cumulated valley dose of 2.8 Gy to the plnning target volume (PTV) (cinical target volume (CTV)+ 1 mm). Thus, each beam delivered 20 to 25 Gy to the target as peak doses, and â¼1 Gy as valley dosesRESULTS:
The treatment was successfully delivered. Clinical follow-up over 3 months showed a significant improvement of the dog's quality of life the symptoms disappeared. Magnetic resonance imaging, performed 3 months after irradiation, revealed reduction in tumor size (-87.4%) and mass effect with normalization of the left lateral ventricle.CONCLUSIONS:
To our knowledge, this neuro-oncologic veterinary trial is the first 3-dimensional conformal synchrotron x-ray MRT treatment of a spontaneous intracranial tumor in a large animal. It is an essential last step toward the clinical transfer of MRT in the near future to demonstrate the feasibility and safety of treating deep-seated tumors using synchrotron-generated microbeams.
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Base de dados:
MEDLINE
Assunto principal:
Neoplasias Encefálicas
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Radiocirurgia
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Glioma
Limite:
Animals
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article