Posted on May 17, 2020
When caught early and treated properly, a brain tumor diagnosis does not have to be life-threatening. But with so many types of brain tumors, accurately diagnosing one can be a complicated process involving an array of tests and specialty doctors. Among the most helpful tools for detection is a brain tumor MRI. To better understand the role medical imaging plays in brain tumor diagnosis, we spoke with expert neuroradiologist, Dr. Michael Rozenfeld.
Today, an estimated 700,000 people in the US are living with a primary brain tumor, and by the end of 2020, over 87,000 more will be diagnosed. - National Brain Tumor Society
From the complexities of differentiating between different types of brain tumors to a breakdown of the grading system used to stage brain cancer, Dr. Rozenfeld offers guidance and advice to help patients navigate a brain tumor diagnosis.
DocPanel is committed to making sure every patient receives excellent care. If you would like an expert second opinion on your medical imaging scan from Dr. Rozenfeld or one of our other neuroradiology subspecialists, you can learn more here.
[DocPanel] What causes brain tumors?
Brain tumors are caused by an abnormal growth of cells, due to mutations or errors in their DNA. There are two types of brain tumors: those that originate within the brain (primary), and those that spread from other parts of the body (metastatic). Of those that arise within the brain, there are benign and malignant tumors.
[DocPanel] How common are brain tumors?
In the United States, the incidence rate of brain and nervous system tumors in adults is 29.9 per 100,000 persons. Of these, 1/3 are malignant and 2/3 are benign.
Metastatic brain tumors, also called secondary brain tumors, occur more frequently than primary brain tumors. Cancers that are known to commonly spread to the brain are lung, breast, colon, kidney, melanoma, thyroid, and uterine.
[DocPanel] What imaging tests are the best for evaluating brain tumors?
In the emergent setting, CT is always helpful to rule out hemorrhage (bleeding) as well as any significant mass effect or herniation. Brain tumor MRI, however, creates more detailed pictures and is therefore required for accurate assessment of the tumor.
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[DocPanel] What imaging findings help differentiate between the different types of brain tumors?
The overall appearance of a brain tumor, as well as knowledge of the patient’s age and history, is often helpful in diagnosing its type. Additional advanced brain tumor MRI techniques, such as MR perfusion and MR spectroscopy, can also help.
[DocPanel] Is a biopsy always necessary to confirm a brain cancer diagnosis?
Most often a diagnosis can be made with a brain tumor MRI. However, sometimes, a biopsy is necessary to accurately diagnose the tumor type. In an ideal world, we would always be able to use imaging to determine who requires surgical resection and who can be monitored. Unfortunately, certain other infectious or inflammatory conditions can occasionally mimic tumors. In such instances, a biopsy may be necessary to determine the best treatment. Whether during a biopsy or surgical resection, tissue analysis is always performed to determine a final diagnosis.
[DocPanel] How is brain cancer staged?
While primary brain tumors may migrate within the brain, they only rarely metastasize outside the brain and are therefore given a grade instead of a stage. The grading system ranges from 1-4, based on factors such as the risk of growth, speed of growth, and risk of recurrence after resection.
[DocPanel] Are there any common pitfalls in grading brain cancer?
While the grade of a tumor can be estimated by the radiologist, it is actually assigned by the pathologist at the time of biopsy or resection. There are, however, certainly some entities that can occasionally mimic aggressive high-grade tumors. These can include abscesses and large demyelinating lesions (such as multiple sclerosis and acute disseminated encephalomyelitis).
[DocPanel] Are there any instances where benign brain tumors require intervention?
‘Benign’ can sometimes be a misnomer in the brain as even small benign tumors can cause significant problems when they are in the proper location. These problems can include hemorrhage, mass effect, herniation, and hydrocephalus. Certain locations can also make resection difficult or even impossible. Whether a tumor or another type of brain lesion, evaluation requires extreme precision.
[DocPanel] For those diagnosed with a brain tumor, the process of determining the type and nature of the tumor can be lengthy and scary - what advice do you have for patients going through this experience?
Brain tumors are best evaluated in a tumor board setting. A tumor board is a meeting between a group of doctors across different specialties who would be involved in the diagnosis and treatment of the tumor (Neuroradiology, Neurosurgery, Neuro-oncology, and Neuro-pathology).
Some of these tumors are complex, and the diagnosis and treatment plan is best made in a collaborative setting. I would advise that your case be presented at a tumor board if complex. With these complex tumors, I would always suggest seeking a second opinion as well. Many centers will assist with this and can send your information to another hospital’s tumor board for review. Most importantly, you want a diagnosis and a team you have trust in. Additionally, support from friends, family, and support groups is extremely helpful in dealing with the physical and emotional consequences of the diagnosis and treatment.
[DocPanel] What role does medical imaging play in brain cancer treatment and post-treatment?
Medical imaging is essential in both the diagnosis as well as the follow-up of brain tumors. This includes tumors that are being watched for potential growth as well as tumors that have been resected and are being watched for recurrence. Imaging should be done at a center with certified neuroradiologists who evaluate large numbers of tumors. Many of these tumors benefit from advanced subspecialized imaging techniques. Diffusion tensor imaging and functional MRI can aid in mapping out important brain structures for surgical planning. Perfusion MRI and sometimes MR spectroscopy can be invaluable in evaluating these tumors pre- and post-treatment. I would strongly suggest getting imaging performed at a center comfortable with these techniques.