What are the chances that my glioblastoma will come back after surgery?

Unfortunately likely: Glioblastoma is not a curable disease in most cases and is very likely to recur after surgery alone. It is strongly recommended that radiation and chemotherapy be administered in addition to surgery.

Highly likely: Gbm is an infiltrative tumor. Even if everything is removed and the mris look "clean", there are seeds of tumor that extend away from the resection bed. These will grow and recur. Radiation and chemotherapy are key in slowing this recurrence. However, even with these treatments, the gbm will recur. New therapies such as vaccines, new chemotherapies, and electric field therapy hold some hope.