The goal of this clinical trial is to evaluate the feasibility, safety and effectiveness of radiotherapy with fewer days of treatment and a higher dose of radiation each day in patients under 70 years of age diagnosed with a brain tumor known as glioblastoma.

The goal of this clinical trial is to evaluate the feasibility (accrual of patients, planning of radiotherapy), safety (acute and late neurological toxicity) and effectiveness (overall survival and progression free survival) of radiotherapy with fewer days of treatment and a higher dose of radiation each day (dose of 60 Gy in 20 fractions of 3 Gy) in patients between 18 and 70 years of age diagnosed with a brain tumor known as glioblastoma. Additionally, circulating tumor cells will be searched in the blood before and after radiotherapy and its quantitative and qualitative analysis will be correlated with the survival outcomes.

Inclusion Criteria:

• Initial histological diagnosis of glioblastoma
• Age > 18 and < 70 years;
• Karnofsky Performance Status > 70%;
• Patient consent to participate in the study.

Exclusion Criteria:

• Patients submitted to any type of previous radiotherapy in the cranial region;
• Multicentric tumors;
• Contraindication to chemotherapy with temozolomide;
• Contraindications for performing magnetic resonance imaging (MRI), such as the use of implants or metallic prostheses;
• Pregnant women or women of childbearing age who refuse to undergo the beta-HCG test before treatment and contraception during the intervention.

All IPD collected throughout the trial,

Beginning 6 months after publication with no end date

A proposal that describes planned analyses must be submitted by a researcher with a history of publishing on the topic