Cancer spread to the brain is one of the most feared complications of cancer that poses significant mortality and morbidity risks in patients with advanced cancer. This occurs when the cancer cells travel through the blood stream or the lymph system from the original tumour and metastasize (spread) to the brain. This is known as metastatic cancer. For example, breast cancer that has spread to the brain would be referred to as metastatic cancer and not primary cancer.
According to the Globocan 2018 report, issued by the International Association of Cancer Registries (IARC) associated with World Health Organization (WHO), more than 28,000 new brain tumour cases are reported annually in India. About 24,000 patients lose their lives every year battling such deadly and cancerous tumours.
Mostly, people ignore the initial symptoms of this disease which include headaches, vomiting, seizures, etc. Doctors often get confused about the exact location of the tumour. This leads to misdiagnosis, which may result in death of the patient. However, the numbers are now gradually declining with improved treatment methods of such deadly tumours.
How to Identify?
The following can be the symptoms of brain metastasis but many patients may experience additional complications caused by the original tumour and its related manifestations.
• Increased pressures within the skull: In most of the cases, symptoms are caused by the expansion of lesions and increased ICP (Increased Cranial Pressure). The most common symptoms of ICP are headaches, vomiting, and disturbance in consciousness.
• Headache: Headache is the initial symptom in more than half of the cases of brain tumour and this is faced by the most of the patients at some point in their life.
• Vomiting: This is an occasional accompaniment with the headaches. It is far more common in children. In children, this can be dramatic and forceful so much it may be labelled as projectile in nature.
• Seizures: It is an uncontrolled and electrical disturbance in the brain. It causes changes in mental behaviour, movements and level of consciousness. These are associated with 35% cases of brain tumours.
• Specific neurological symptoms: Whereas headaches alter mental status and seizures may be seen with the tumour that occurs in any part of the brain, some symptoms are associated with the tumours that occur in a specific location. These symptoms affect the side of the body opposite from the side where tumour resides and may include different modalities of sensation such as tingling and motor changes.
Causes
Virtually any systemic malignancy can metastasize to the brain, but there are some which have greater tendency to do so. Melanoma (a type of skin cancer) has a tendency to metastasize to the brain. Other cancerous tumours in skin, breast, renal and colon areas can also metastasize to the brain. Some differences are seen in the types of primary malignancies responsible for metastasis of the brain in both the genders. In males, lung cancer is the most common source of brain metastasis whereas breast cancer is the most common source in females.
Diagnosis
Brain metastasis can be diagnosed with the following tests:
CT/CAT scan: It can be done with or without injecting intravenous contrast and includes different views of the brain. CT scans are the initial diagnostic tests utilised.
Magnetic Resonance Imaging (MRI): It makes for a clear picture of the brain using powerful magnets and radio waves. With the addition of intravenous contrast agent, this is the gold standard testing that provides information about the location, size, characteristics, and pressure effects of the tumour.
PET Scan: Positron Emission Tomography (PET) scans can show up a cancer, reveal the stage of the cancer, show whether the cancer has spread, and help doctors decide on the most appropriate cancer treatment as well as give an indication of the effectiveness of ongoing chemotherapy. The biggest advantage of a PET scan, compared to an MRI scan or X-ray, is that it can reveal how a part of the patient’s body is functioning, rather than just how it looks. Medical researchers find this aspect of PET scans particularly useful. A CT or MRI scan can assess the size and shape of body organs and tissue, but cannot assess its function, which a PET scan does. In other words, MRI or CT scans tell you what an organ looks like, while a PET scan can tell you how it is working.
Tissue diagnosis: It may be obtained by a biopsy or removal at the site of the primary cancer. Besides this on other occasions, a biopsy of the metastatic brain tumour is performed if the size is larger and causing significant pressure effects. The tumour may be removed entirely to relieve the pressure while providing the adequate tissue for diagnosis.
Once a clear diagnosis of the tumour is obtained, staging of the systemic cancer is completed and the patient’s medical condition is stabilised, a multidisciplinary team of physicians will try to treat the tumour within the brain with best possible treatment methods.
Cyberknife M6 over other traditional methods of treatment
This treatment varies with the size and type of tumour. The primary sites of malignancy are assessed both locally and in rest of the body. The general health of the individual and presence of other medical problems are taken into acccount. The goals of the treatment involves improve body functioning, controlling the cancer and its satellite tumour within the brain.
Cyberknife M6 is performed in a non-invasive manner. It pinpoints the exact location of the tumour in real time using 3-D imaging techniques. There is flexibility in the treatment as it can be done in 1 to 5 sessions each of 30 minutes duration, thus being more comfort to the patient. It is the most effective way of restricting the tumour from spreading further.
The main advantage of Cyberknife radiation therapy is that it directly alters the individual deposits inside the brain without affecting the brain functioning. Also, Whole Brain Reserve Therapy (WBRT) is reserved for those unfortunate patients who have too many deposits that cannot be treated with Cyberknife or those who prefer multiple Cyberknife treatments. For treatment of metastasis such as melanoma, radiation therapy (Cyberknife) may be the only option.

—The writer is Director, Cyberknife, Artemis Hospital, Gurugram

Dr Aditya Gupta