This study is for people with a newly diagnosed brain cancer called GBM, which stands for glioblastoma multiforme. GBM is a fast-growing type of brain tumor. The study aims to see if a new treatment called GammaTile (GT) can help improve outcomes when combined with the standard care, known as the Stupp Protocol. GT uses a special type of radiation called Cs-131, which is placed directly at the tumor site during surgery. This allows for faster and potentially more effective treatment. The Stupp Protocol involves chemotherapy with a drug called temozolomide (TMZ) and regular radiation therapy. The study will ensure that the combination of these treatments is safe and well-tolerated. Participants will receive both GT and traditional radiation treatments. Researchers will monitor the tumor's response and overall survival rates. To join, patients must be 18 or older and able to follow the treatment plan. They must also meet specific health criteria.

• The study lasts until the treatment and follow-up are complete.
• Participants must attend regular visits for treatment and monitoring.
• Potential benefits include improved treatment effectiveness, but risks include side effects from radiation and chemotherapy.