Diagnosing glioblastoma involves several steps to determine the tumor’s type, size and location. These tests and evaluations are commonly used:
Neurological Exam:
- A healthcare provider checks reflexes, strength, coordination, vision, hearing, sensation and balance.
- Any abnormalities may provide clues about which part of the brain is affected.
Imaging Tests:
- MRI (Magnetic Resonance Imaging): This is the primary test for glioblastoma, offering detailed images of the brain to locate and evaluate the tumor’s size and characteristics. Sometimes, a contrast dye is used to improve clarity.
- CT (Computed Tomography): Though less detailed than an MRI, CT scans can also identify the tumor’s location and size.
- PET (): This test evaluates the tumor’s metabolic activity, helping to determine its aggressiveness.
Additional tests, such as an EEG (), may be done to assess brain activity and detect seizures. This comprehensive approach helps healthcare teams create an effective treatment plan tailored to the patient’s needs.
Stages of Glioblastoma
Glioblastoma is not classified by stages like some cancers. Instead, brain cancers are “graded” based on how abnormal the cells look under a microscope and how quickly they are likely to grow and spread.
The grading system ranges from 1 to 4. All glioblastomas are grade 4 tumors, according to the World Health Organization (WHO) grading system. This designation reflects their aggressive nature and rapid growth. Grade 1 and 2 tumors are typically non-cancerous and grow slowly, while grade 3 and 4 tumors are cancerous and progress quickly.
Glioblastomas are grade 4 because:
- The cells appear highly abnormal and share few characteristics with healthy cells.
- They grow and reproduce at a fast rate, often invading nearby brain tissue.
- These tumors form their own blood vessels to support growth and may contain calcium deposits or cystic material.
This grading highlights the severity of glioblastomas and helps guide treatment planning.
