What Is Glioblastoma?
Glioblastoma is a high-grade tumor arising from the brain's supporting cells, the glial cells (particularly astrocytes). In the 2021 WHO classification of central nervous system tumors it is defined as a grade 4 astrocytic tumor (IDH-wildtype). Microscopically it is characterized by marked cell proliferation, increased blood vessels (microvascular proliferation) and areas of necrosis. Because it infiltrates the surrounding brain with finger-like extensions, even when its border looks well defined on imaging it has spread microscopically; this feature explains why treatment cannot be limited to surgery.
Symptoms and Diagnosis
Symptoms depend on the tumor's location and growth rate and usually progress over weeks. Common features include progressively worsening headache, nausea and vomiting from raised intracranial pressure, seizures, speech or movement disturbances, and personality and cognitive changes. Contrast-enhanced brain MRI is the first-line study; it typically shows a ring-enhancing mass with central necrosis surrounded by extensive edema. Definitive diagnosis is made by pathological and molecular analysis (IDH status, MGMT promoter methylation) of tissue obtained at surgery or biopsy; these molecular markers influence treatment and course.
Surgery Alone Is Not Enough
The standard approach to glioblastoma is the widest possible safe surgical resection followed by concurrent radiotherapy and temozolomide chemotherapy (the Stupp protocol). The aim of surgery is to reduce the tumor burden as much as possible and to provide a tissue diagnosis; however, because the tumor infiltrates microscopically, surgery does not provide a 'cure', and the subsequent treatments are essential. To perform the resection while preserving function, neuronavigation, functional mapping, awake craniotomy when needed and fluorescence-guided (5-ALA) techniques are used. The entire decision is made by a multidisciplinary team in which neurosurgery, radiation oncology and medical oncology work together.
The Surgical Process
During preparation a detailed neurological examination, contrast MRI, and when needed functional MRI and DTI tractography, a multidisciplinary meeting and an anaesthetic assessment are carried out. In surgery the patient is positioned according to the tumor location; tumors close to a functional area are operated awake when required. A narrow shave within the hairline is sufficient, the bone flap is removed, the dura is opened, and the tumor is removed under the microscope with navigation guidance. Afterwards there is usually 24–48 hours of intensive care and a few days in hospital; the extent of resection is assessed with a control MRI, and the radiotherapy-chemotherapy course usually begins within a few weeks.
Honest Expectation Management
Glioblastoma is an aggressive tumor and, despite current treatment, its prognosis remains limited; saying this honestly is our responsibility as physicians. Molecular features such as MGMT promoter methylation can influence treatment response and course. Treatment often aims to control the disease, reduce symptoms and preserve quality of life as much as possible. The risks of surgery (bleeding, infection, a temporary or permanent neurological deficit, edema, seizures) are discussed openly. We do not promise a guaranteed result; each patient's course is different, and expectations are shared clearly before surgery.