This information is intended to provide a general overview of Brain Metastases. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider for any health concerns or before making any decisions related to your health.
Brain metastases are cancerous growths that have spread to the brain from a primary cancer located elsewhere in the body. They are medically distinct from primary brain tumours, which originate in the brain tissue itself, and are far more common.
An estimated 150,000 to 200,000 people are diagnosed with a brain metastasis each year globally, significantly higher than the approximately 17,000 diagnoses for primary brain tumours. The number of brain metastasis diagnoses has been increasing, which many medical professionals attribute to improved early detection and more effective treatments for primary cancers. As patients with primary cancer live longer, the disease has more time to potentially spread to the brain, leading to a critical focus on advanced brain metastasis treatment.
Any cancer has the potential to spread to the brain, but the most common sources include:
Breast cancer
Lung cancer
Melanoma
Colon cancer
Gynaecologic cancers
Renal cell carcinoma
A cancer can spread to a single location or to multiple locations within the brain.
It can also spread to the cerebrospinal fluid (CSF) or the leptomeninges—the delicate outer lining of the brain and spinal cord. This is known as Leptomeningeal Disease (LMD) or leptomeningeal carcinomatosis. Due to cancer cells floating in the CSF, LMD can spread rapidly throughout the central nervous system and often carries a poor prognosis.
The brain, spinal cord, and nerves form the Central Nervous System (CNS), which is responsible for processing all our senses, emotions, and movements. The brain is protected by the skull, and the spinal cord is protected by the vertebrae of the spine. An additional layer of protection is provided by the cerebrospinal fluid (CSF) surrounding both structures.
The brain has four main parts:
The outer and largest part of the brain, split into two hemispheres, each with four lobes (frontal, parietal, temporal, and occipital). It controls the senses (sight, hearing, smell, touch), language, emotional reasoning, and movement.
Deeper structures that play a role in the control of movement.
Located at the back of the brain, it is crucial for controlling and coordinating movement, such as walking and balance.
Situated in front of the cerebellum, it relays sensory and motor messages between the cerebrum and the rest of the body. It plays a vital, life-supporting role in functions like breathing and regulating heart rate.
The specific symptoms of a brain metastasis are directly related to the tumour's size and location. For example, a growth in the part of the brain that manages vision may cause visual disturbances.
The diagnostic process begins with a detailed series of questions from your oncologist regarding any recent mental, emotional, or physical changes you have experienced. These questions help to determine the likelihood of a brain metastasis and suggest the potential location of the tumour.
Initial steps include a physical examination and an imaging exam, typically a Magnetic Resonance Imaging (MRI) scan, which is the most common method to locate and confirm a brain metastasis diagnosis.
If the MRI is inconclusive, doctors may recommend a biopsy, where a piece of the suspected tumour is removed and tested. This can be performed surgically or with a guided needle, though the tumour's location may make a biopsy difficult or inadvisable.
Sometimes, metastatic disease is found incidentally during an imaging exam for an unrelated reason. Discovering a brain metastasis before symptoms begin may allow for earlier treatment to prevent neurological issues.
LMD is diagnosed by testing the cerebrospinal fluid (CSF) for cancer cells. This requires a lumbar puncture (or spinal tap), where a needle is inserted into the lower back to remove a small CSF sample for analysis. This procedure may be repeated up to three times to increase the chance of identifying tumour cells.
Treatment for brain metastasis is developed by a dedicated team of specialists in neuro-oncology, neurosurgery, radiation oncology, and radiology, alongside physicians specialising in the primary cancer. This multidisciplinary group collaboratively reviews each case to create a personalised treatment plan aimed at achieving the best possible outcome for the individual patient.
Surgery is often an option, depending on the number, size, location, and symptoms of the metastasis. It is most frequently used for a single, large brain metastasis. The goal is to safely remove as much of the tumour as possible while preserving vital brain function.
SSCHRC neurosurgeons are highly skilled and use advanced, minimally-invasive techniques.
Even when complete tumour removal is not feasible, surgery can still help to reduce the tumour's size, alleviate symptoms, and inform doctors about necessary follow-up treatments.
The most common surgery is a craniotomy, where a section of the skull is removed to allow for resection (removal) of the tumour. Other treatments are used when a tumour's location makes surgical removal too risky to brain function.
Radiation therapy uses high-energy beams to stop or slow the growth of brain metastases. It can be used as a stand-alone treatment, an alternative to surgery, or in combination with other therapies.
SSCHRC doctors employ advanced radiation methods for precise targeting, delivering a maximum dose of radiation with minimal harm to healthy surrounding cells. These methods include:
Chemotherapy was historically not a primary treatment for most brain metastases due to the blood-brain barrier—a protective membrane that limits many drugs from reaching the brain effectively.
However, recent research suggests that several promising chemotherapies may play an important role in treating specific brain metastases.
Treatment for Leptomeningeal Disease (LMD): Chemotherapy can be administered directly into the cerebrospinal fluid to treat LMD. This technique, called intrathecal chemotherapy, requires a small surgical procedure to insert a special port called an Ommaya reservoir into the skull. Since this technique can only penetrate a few millimetres into the leptomeninges, doctors may use radiation to shrink thicker tumour growths first.
LITT is a minimally invasive treatment option, requiring only a small incision. A laser probe is inserted into the tumour and heated to a temperature high enough to destroy the cancerous tissue. LITT is often an option for metastases that cannot be safely removed with conventional surgery due to their location. Most patients can return home the day after treatment and quickly resume normal activities.
Immunotherapy uses the body's own immune system to identify and fight cancer cells. These newer treatments are proving effective in treating melanoma brain metastases and are being actively studied for use in other tumour types.
Targeted therapies are designed to interfere with the specific gene mutations that drive cancer growth. Several of these drugs are currently under investigation in clinical trials for patients with specific types of cancer.