Combined Treatment of Patients With Newly Diagnosed Glioblastoma Using the Xoft® Axxent® Electronic Brachytherapy (eBx®) System for Intraoperative Balloon Electronic Brachytherapy

Inclusion criteria

• The subject's age must be ≥ 40 years but not older than 75 years.
• The subject's Karnofsky Performance Status (KPS) must be ≥ 70%.
• The subject is willing and able to independently provide informed consent for participation in the study.
• The subject has been newly diagnosed with glioblastoma (GB) based on preoperative neuroimaging (contrast-enhanced brain MRI ± amino acid-based PET/CT) and confirmed by intraoperative histopathological examination of the tumor.
• Total or near-total resection of the contrast-enhancing tumor portion is feasible.
• The expected post-resection cavity size must allow placement of the Axxent Xoft eBx balloon applicator system.
• Women of childbearing potential must have a negative pregnancy test within 7 days before treatment initiation.
• The subject must have a complete blood count (CBC) with or without differential within 7 days before study enrollment, demonstrating adequate bone marrow function:

• Absolute neutrophil count (ANC) ≥ 1500 cells/mm³
• Platelets ≥ 75,000 cells/mm³
• Hemoglobin ≥ 10.0 g/dL
• The subject must undergo kidney and liver function tests within 7 days before study enrollment, with the following required parameters:

• Total bilirubin ≤ 2.0 mg/dL, and AST ≤ 2.5 × upper limit of normal (ULN)
• Serum creatinine ≤ 1.8 mg/dL within 14 days before enrollment.
• The subject's urine protein levels must meet the following criteria within 14 days before enrollment:

• Urine protein-to-creatinine ratio (UPCR) < 1.0, OR
• Dipstick urinalysis ≤ 2+ proteinuria (if > 2+, a 24-hour urine collection must show ≤ 1 g protein/24h).
• Patients on anticoagulant therapy (e.g., warfarin or low-molecular-weight heparin) must meet all of the following:

• No active bleeding or high-risk bleeding conditions (e.g., tumor involving major vessels or varices).
• Stable INR (typically 2-3) on oral anticoagulants OR stable dose of LMWH for ≥ 14 days before enrollment.

Exclusion criteria

• Multicentric/multifocal glioblastoma growth.
• Infratentorial or leptomeningeal tumor spread.
• Recurrent/progressive glioblastoma.
• Prior cranial radiation therapy.
• Glioblastoma located in or near (≤ 10 mm from) critical brain structures, preventing adequate radiation dose delivery.
• Contrast-enhancing tumor diameter > 6 cm.
• Active or prior malignancy (except adequately treated non-melanoma skin cancer or carcinoma in situ).
• Other intracranial neoplasms (current or history).
• Pregnancy, lactation, or unwillingness to use effective contraception (for women of childbearing potential or sexually active men).
• Contraindications to MRI (with or without gadolinium).
• Non-removable or clinically inoperable cardiac pacemaker/device.
• Contraindications to general anesthesia.
• Concurrent participation in another clinical trial.
• Severe comorbidities, including:

• Unstable angina or congestive heart failure requiring hospitalization (within 6 months).
• Transmural myocardial infarction (within 6 months).
• Stroke or transient ischemic attack (within 6 months).
• Significant vascular disease (aortic/peripheral).
• Active venous/arterial thromboembolism.
• Acute bacterial/fungal infection requiring IV antibiotics.
• COPD exacerbation or respiratory disease interfering with protocol therapy.
• Liver failure causing jaundice/coagulopathy.
• Positive serology for HIV, HBV, HCV, or syphilis.
• Grade ≥ 3 hemorrhage (CTCAE v5.0) within 30 days before enrollment.