Banner Health
Making healthcare easier

Brain Cancer Tests, Diagnosis, Grades and Prognosis

The multidisciplinary teams at Banner MD Anderson Cancer Center bring together expertise from across the medical and cancer care spectrum to provide advanced and compassionate care. We are here to make sure you understand the various tests used to diagnose brain cancer, what to expect and to answer any questions you may have.

What Tests Screen for Brain Cancer?

There are different tests available for detecting brain cancer. Your doctor will determine which one is best based on the symptoms you’re experiencing, as well as your risk factors. Our physicians urge our community of patients to continue to practice safe and healthy living habits and always seek immediate medical attention when they experience unexplained or concerning neurological symptoms.

Imaging Tests

There are multiple brain and spinal cord imaging tests available. Imaging tests can be done either to detect if cancer or a tumor is present or to determine if treatment is working effectively. The two most widely used imaging techniques include magnetic resonance and computed tomography scans.

Magnetic Resonance Imaging (MRI) scans use radio waves and strong magnets to create images of your brain and spinal cord tissues. This test produces detailed images of the tissues and is generally the preferred diagnostic imaging test for tumor surveillance. However, alternative scans exist for patients who cannot tolerate MRI scans.

Computed Tomography (CT) scans use x-rays to make detailed 3-dimensional cross-sectional images of your brain and can help identify the tumor location, density and size. These scans are especially useful to evaluate for bleeding or bony invasion of the tumor. CT scans are ideal for people who cannot undergo MRI scans because of the use of magnets, like those individuals with certain indwelling devices (pacemakers, surgical clips, etc.), or other medical reasons as determined by the patient and their care provider.

Both MRI and CT scan can be used as an initial screening tool. Also, both techniques can be adapted to allow for more advanced brain tumor imaging as needed based on the physician’s preference.


A biopsy is when a sample of tissue is removed and examined under a microscope to see if any cancerous cells are present. While imaging tests may show an area where there may be a brain tumor, your doctors need a tissue sample to definitively diagnose a primary brain tumor. Your doctor can perform a biopsy by removing a small sample of tissue with a needle or removing all or part of a tumor through surgery.

Lumbar Puncture (LP)

During a lumbar puncture, also known as a spinal tap, a needle is used to take a sample of the cerebrospinal fluid (CSF) that bathes your brain and spinal cord. This fluid is tested to look for tumor cells, blood or other tumor markers. This is a relatively safe outpatient procedure used in many neurology practices. Currently, CSF is the only body fluid approved to definitively identify certain brain tumor types. Our team of physicians and scientists are working with teams across the country to identify other body fluids that might hold clues for earlier brain cancer screening. 

Brain Function Tests

  • Neurological, vision and hearing tests. These tests determine if a tumor is affecting how the brain functions. These examinations can detect changes neurological functions that might point to areas of the brain or spinal cord that are affected. 
  • Neurocognitive assessment. This consists of a detailed evaluation of all major functions of your brain, such as storage and retrieval of memory, expressive and receptive language abilities, calculation, judgement, and your overall sense of well-being.
  • Electroencephalography (EEG). An EEG is a noninvasive test in which electrodes are attached to the scalp to measure electrical activity of the brain. It is used to monitor for possible seizures or risks for seizures.
  • Functional Magnetic Resonance Imaging (fMRI). This is an application of MRIs and is used to see what parts of your brain perform certain functions. It is used pre-surgically to ensure that vital tissue is not impacted or removed.

Once your multidisciplinary team has a good understanding of the type, location, size and grade of your brain tumor, they will sit down with you to discuss the results, explain their recommended treatment approach and what to expect. We take special care to inquire about your wellness goals and values and answer any questions you or your involved caregivers or family members might have to ensure we offer compassionate care.

What Are the Grades of Brain Cancer?

Brain and spinal cord cancer grading helps physicians to anticipate tumor aggressiveness and offer a prognosis to patients. Primary brain cancers almost never spread outside the brain or spinal cord. Brain and spinal cord tumors are typically assessed on a graded scale from 1 (being least aggressive) to 4 (being most aggressive). Pathologists work to assign a tumor grade based on the number of cells multiplying and how different they look as compared to healthy cells.

  • Grade 1: Tumor cells are nearly identical to healthy cells except they are more numerous. They are slow growing and associated with high rates of survival.
  • Grade 2: Tumor cells look slightly different from healthy cells. While they are still considered low-grade, grade 2 tumors are more aggressive than grade 1 tumors. A grade 2 tumor has the potential to transform to a higher grade tumor.
  • Grade 3: Tumor cells look abnormal and actively multiply. Grade 3 tumors grow faster than grade 2 tumors and have the potential to transform to grade 4 tumors.
  • Grade 4: These tumors are the most aggressive. They do not look like normal cells and are actively dividing. There may also be areas of dead cells within the tumor and/or increased blood vessel formation in these aggressive tumor grades.

What Is the Prognosis for Brain Cancer?

Brain cancer is rare and fewer than 1% of people will develop brain cancer. Primary, cancerous brain tumors are the most life-threatening and have about a 36% survival rate. Best indicators for longer survival include young age, early detection, lower grade, good patient baseline health and function, as well as working with a team of well-trained physicians to offer effective and evidence-based care.

We know that a diagnosis of brain cancer can be concerning, but getting treatment at Banner MD Anderson is one of the best steps you can take. Your multidisciplinary care team is here to provide the high-level care and help you understand your next steps after a brain cancer diagnosis.

Request an appointment