Glioblastoma (WHO Grade 4 astrocytoma, IDH-wild type) is the most common and aggressive primary malignant brain tumor in adults. It arises from the brain's supportive glial cells and infiltrates diffusely into the surrounding tissue, so it has no true capsule or clear boundary. That infiltrative growth pattern means microscopic extensions of the tumor can remain in the surrounding tissue even when the visible mass appears to have been fully removed. Surgery is almost always the first step, but for these reasons treatment isn't confined to surgery alone.
It typically progresses quickly, with symptoms often developing over just a few weeks. The final diagnosis and treatment plan are confirmed through pathological and molecular analysis of tissue obtained during surgery.
Symptoms usually progress quickly and vary with the tumor's location. Common presentations include:
Contrast-enhanced MRI is the standard diagnostic tool and typically shows a characteristic appearance, ring enhancement around a necrotic center with surrounding edema. Perfusion MRI or MR spectroscopy is used when needed to help distinguish the tumor from lymphoma, metastasis, or abscess. The definitive diagnosis is confirmed through pathological and molecular analysis, IDH status, MGMT methylation, and other genetic markers, of tissue obtained during surgery, and that information directly shapes the treatment plan.
For patients diagnosed with glioblastoma, the standard approach is surgery, without much debate; surgical resection is essentially always the first option. Biopsy alone only comes up when the tumor can't be safely operated on.
As first-line treatment, techniques such as neuronavigation, fluorescence-guided methods (fluorescein, 5-ALA), and intraoperative ultrasound are used together to define the tumor's margins more precisely. Even so-called "butterfly gliomas" — tumors crossing the corpus callosum to involve both hemispheres — can still be considered for upfront resection. Surgery is followed by six weeks of concurrent radiotherapy and temozolomide chemotherapy, then roughly six months of adjuvant temozolomide.
In deep or high-risk locations, or in patients with a poor performance status or advanced age, safe complete resection may not be possible. In these cases a stereotactic biopsy confirms the diagnosis first, followed by standard or shortened (hypofractionated) radiotherapy and chemotherapy tailored to age and overall condition.
If the tumor recurs or progresses, it's reassessed; depending on the situation, re-operation, tumor treating fields (TTFields), second-line chemotherapy, or a clinical trial may become options.
Explore how the decision is made for glioblastoma, and what a typical treatment course looks like.
Contrast-enhanced MRI defines the tumor and its relationship to surrounding structures; perfusion MRI or spectroscopy help when the imaging isn't classic.
Location, size, and the patient's age and performance status are weighed together, with radiation oncology and medical oncology involved from the start.
From here, the right path depends mainly on whether the tumor can be safely operated on. Tap a profile to see more.
Regular MRI monitoring throughout and after treatment confirms the tumor remains under control.
Imaging, labs, anesthesia clearance, and neuronavigation planning; awake surgery and brain mapping are considered separately when the tumor sits near eloquent cortex.
Maximal safe resection is carried out with neuronavigation, fluorescence-guided techniques, and intraoperative ultrasound working together to define the margins. Larger tumors or higher-risk locations warrant a night of ICU observation. Early post-op imaging confirms the result.
A repeat neurological exam, pain control, and gradual mobilization under close observation; this early window is when any post-operative neurological change would first appear.
Patients with a stable neurological exam go home with instructions.
Pathology is typically back within about a week; the fuller molecular workup (IDH status, MGMT methylation) takes closer to four. As results come in, additional treatment is planned and started together with radiation oncology.
Six weeks of concurrent radiotherapy and temozolomide chemotherapy, followed by roughly six months of adjuvant temozolomide and regular MRI follow-up.
Shown for a typical, uncomplicated case. Individual treatment course may vary.