Advanced Brain Tumor Surgery: Abnormal growth of cells in the brain is called brain cancer or brain tumor but not all brain tumors are cancerous. They can be of two type malignant (cancerous) and benign that are less serious than malignant tumors but it can still cause other problems in the brain by putting pressure on nearby tissues. Malignant tumors can grow abnormally and spread aggressively to other distant parts of the body. Malignant or cancerous tumors can be divided into primary tumors that originate within the brain and secondary tumors also known as metastasis tumors that have spread from some other parts of the body. Some of the most common primary and secondary brain tumors are:
Primary Brain tumors:
3. Pituitary adenomas
4. Vestibular schwannomas
Secondary brain tumors:
2. Breast cancer
3. Renal cell carcinoma
4. Colorectal cancer
Most of the brain cancers do not have known cause but it can occur due to genetic factors, environmental toxins like exposure to vinyl chloride, ionizing radiation to head, infections like HIV, substance abuse. All of brain tumors depending on the part it is affecting can produce some symptoms weakness, difficulty in walking, blurred vision, nausea and vomiting, seizures, headaches, mental or behavioral changes, slurred speech, sensation. Doctor may suggest initial tests for cancer that includes a brief medical history and physical examination of the patient and other important test are:
1. Computerized Tomography (CT scan) – series of x-rays, sometimes in which a dye needs to be injected into a vein for better images of internal brain structures.
2. Magnetic resonance imaging (MRI) - x-ray that give better details than the CT scan. It gives more information on the chemical composition of the brain. A spinal MRI is used to diagnose tumor on or near the spine. A functional MRI (FMRI), provide details about the specific areas of the brain that are responsible for muscle movement and speech. This is very essential test to plan a surgery to avoid damaging the other functional parts of the brain while removing the tumor.
3. Biopsy or tissue sampling – a small amount of tissue is removed from the tumor for examining it under the microscope to diagnose disease. It can be done as part of surgery to remove the whole tumor.
4. Positron emission tomography (PET scan) – is used to create images of the internal body organs and tissues. Small amount of radioactive tracer (glucose) is injected into the body that travels to the cells that consume glucose for energy. Radiotracer will built up in the area where group of cells need more energy. These active areas are brighter and are called hot spots and where cells needs less energy those are called cold spots as they are less bright. Cancer cells are more active in using glucose than the normal cells that can be seen in PET scan.
Some other tests including cerebral angiogram, lumbar puncture, myelogram, molecular testing of the tumor, neurological test, electroencephalography etc may be done to diagnose the problem.
Treatment may include anti-seizure/ antiepileptic drugs, steroids or surgery based on the factors like age, medical history, current health status, type, area and size of the tumor. Other treatments for high grade tumor include radiation therapy, chemotherapy, targeted therapy, tumor treating fields.
Surgery is considered as the primary option for treating the brain tumor and it is majorly depends on the area where the tumor is present, size of the tumor, medical history of the patient, overall health condition and radiographic images. If only a small amount of tumor can be removed safely then the surgeon would prefer to perform a biopsy to identify the type of tumor and would prefer to use non-operative therapies like radiation. Following are some advance surgeries for treating brain tumor:
1. Craniotomy – means cutting into the head as close to the tumor as possible. Some tumors can be removed by approaching through the nose or the top of the neck while others can be approached through the scalp and the skull to expose the upper part of the brain called cortex. During this procedure, an incision is made on the shaved scalp skin and a piece of skull bone is removed to expose the brain. In some cases, surgeon may do some mapping to identify the functional areas of the brain once it is exposed.
2. Biopsy - A sampling of tissue for examining and diagnosing of the tumor from a surgery is known as biopsy. The tissue for biopsy can be obtained through craniotomy or through a smaller surgery called stereotactic biopsy. Surgeon will make a small hole in to the skull and uses imaging to guide a needle into the brain and tumor to remove some tissue as a sample. Surgeon with his team may decide whether to proceed with a biopsy or larger craniotomy.
3. Shunts – Brain is very sensitive to the pressure changes inside the skull. It can be proved fatal if increases rapidly and can impair the brain functions. This can be treated with simple relatively simple procedure called shunt. A thin tube called shunt is placed into a ventricle of the brain through a small hole made in the skull which moves excess fluid from the brain to another part of the body such as heart or abdomen where it is absorbed into the bloodstream. Sometimes, shunt surgery can become a potential problem as in order to move fluid from the brain to the other parts of the body, surgeon may unknowingly move the brain tumor cells along the fluid.
4. Mapping - there are many ways to “map” the brain. Some of them does not require opening the head and may involve using a special technique such as functional MRI, PET or SPECT scan, magnetoencephalogram (MEG) to localize motor, sensory and language function, probing the brain using special computerized wands, stimulating brain tissue with tiny electrical currents.
5. Embolization – blood supply to tumors can be shut off by using a variety of plugs that block the artery from the inside causing the tumor to die from lack of blood flow. Mostly, the blockage is performed through an endovascular approach or may also be performed by direct percutaneous injection of embolic agents into the tumor. This procedure usually may require single session along with arteriography but can also be performed in multiple staged sessions.
6. Computer assisted volumetric stereotaxis – this method can be performed for gathering, storing and reformatting image-derived volumetric information
7. Gamma knife surgery – it is a minimally invasive neurosurgical method that requires radiation to treat the diseased brain tissue without damaging the nearby tissues and there is no surgical incision required to expose the tumor in this surgery. This procedure can be a great help in treating patients with brain tumors, vascular malformation and other functional disorders.
There are some other additional procedures for brain cancers including thermal destruction equipments like lasers that can be placed in the exact spot to destroy tumor tissue, some tumors can be efficiently treated by breaking them up and removed out of the brain with the less damage to normal brain tissue. This procedure is called ultrasonic aspiration, radiation or chemotherapy can be used depending on the problem.
Post brain tumor surgery, patient may require certain therapies to improve strength and coordination of the brain. Patient should avoid head baths for certain period of time, should not use hair color or dyes, travelling by air should be avoided as cabin pressure may cause problem to the patient’s brain, should avoid rigorous exercise and sports, heavy drinking as it can cause seizures.