ASNR Neuroradiology Patient Information

What is a Brain Tumor?

Brain tumor is an abnormal and often uncontrolled growth of cells, and takes up space within the cranial cavity (skull). It can compress, shift and/or invade and damage healthy brain tissue and nerves and usually interferes with normal brain function.
Tumors can be benign (non-cancerous) or malignant (cancerous), can occur in different parts of the brain, and may or may not be primary tumors. A primary tumor is one that has started in the brain, as opposed to a metastatic tumor, which is something that has spread to the brain from another part of the body.

Aside from exposure to vinyl chloride or ionizing radiation, there are no known environmental factors associated with brain tumors. Certain genetic diseases, which lead to mutations and deletions of so-called tumor suppressor genes, are thought to be the cause of some forms of brain tumors. People with various inherited diseases, such as Von Hippel-Lindau syndrome, multiple endocrine neoplasia, neurofibromatosis type 2 are at high risk of developing brain tumors.
Although studies have not shown any link between cell phone radiation and brain tumors,1 the World Health Organization has classified mobile phone radiation on the International Agency for Research on Cancer (IARC) scale into Group 2B - possibly carcinogenic. That means that there "could be some risk" of carcinogenicity, so additional research into the long-term, heavy use of mobile phones needs to be conducted.2

Brain tumors can present with a variety of symptoms, which could range from simple headache to weakness of one side of the body, depending upon the location of the tumor as these can interfere with brain function and activity. Sometimes brain tumors may not be symptomatic and can be discovered on scanning done for some other reason.
Following symptoms can be due to a brain tumor:
- +A new seizure in an adult person
- +Gradual loss of movement or sensation in an arm or leg
- +Speech difficulty of gradual onset
- +Unsteadiness or imbalance, especially if associated with headache
- +First headache in patient over 50 years old
- +Headache in children under 6 years old
- +A steady headache that is worse in the morning than the afternoon, a persistent headache that is associated with nausea or vomiting, or a headache accompanied by double vision, weakness, or numbness all suggest a possible tumor.
- +Change in behavior, rapid decline in school results or patient performance
- +Memory loss, loss of concentration, and general confusion
However, please also note that in most cases the above detailed symptoms may not be due to a brain tumor and may be associated with another ailment.
If you are concerned that you or someone you know might have a brain tumor, call your doctor. If symptoms persist, an MRI (magnetic resonance imaging) or CT (computed tomography) scan can facilitate the diagnosis. Early detection and treatment may improve survival.

Your doctor will evaluate your symptoms and perform a complete physical examination which will include a detailed neurological and eye (to look for signs of increased pressure in the brain) examination. Subsequently, your doctor may decide to investigate further with brain scans. Usually the first imaging investigation is a CT scan of the brain. In most cases, a CT scan is sufficient to rule out a large brain tumor. However, in cases where CT scan detects an abnormality or if your doctor thinks that you have enough signs and symptoms which need more detailed scanning, he/she might order an MRI.
The most important information your doctor needs to know if a brain tumor is detected on any of these initial tests is - the exact size and location of the tumor in the brain and also if it is causing any swelling or compression of the brain which might need urgent attention.

Imaging plays an important role in detection of a brain tumor. With the advances in technology, usually the first imaging test your doctor will order is a CT scan of the brain. This is usually done with injection of an x-ray contrast (dye), though CT scan done even without the x-ray contrast is also sufficient as the first imaging test. MRI with injection of contrast is a more definitive and detailed imaging test which can detect or rule out a brain tumor in most cases. MRI is especially important once a brain tumor is detected, in order to provide more detailed information about tumor size, location and compression of adjacent brain structures. This information would be very valuable to plan further treatment which may include surgery. Your doctor might have to test your kidney function with a simple blood test, before CT or MRI contrast can be injected.
Other Imaging Tests: Depending upon the suspected tumor type, your doctor might order other imaging tests which may include CT/MRI of the rest of the body (to look for another tumor as the cause of brain tumor or associations with certain other disease processes). Additional imaging tests may also include use of certain special imaging techniques such as advanced MRI methods (including but not limited to perfusion studies, MR spectroscopy, diffusion tensor imaging and/or functional MRI) or PET (positron emission tomography). These might need additional visits and also additional injection of contrast.

Definitive Diagnosis: The diagnosis of a brain tumor can only be confirmed by histological examination of tumor tissue samples, done by a pathologist after the tissue samples are obtained by a neuro-surgeon either by means of brain biopsy or open surgery.

The radiologist will usually go through your medical records, history and physical examination findings and then dictate the results of your imaging scan. These results will be conveyed to you and your doctor by way of a written report and also by way of personal communication or phone call in case your results indicate that you might need urgent attention. A radiologist would also be happy to discuss preliminary results of your imaging tests if you need to, usually immediately after the test.

References:

+Frei, P; Poulsen, AH, Johansen, C, Olsen, JH, Steding-Jessen, M, Schüz, J (19 October 2011). "Use of mobile phones and risk of brain tumours: update of Danish cohort study.". BMJ (Clinical research ed.) 343: d6387. doi:10.1136/bmj.d6387. PMC 3197791. PMID 22016439
+IARC classifies radiofrequency electromagnetic fields as possibly carcinogenic to humans" (Press release). International Agency for Research on Cancer. 31 May 2011. http://www.iarc.fr/en/media-centre/pr/2011/pdfs/pr208_E.pdf. Retrieved 2011-06-02.