Diagnosis is different for every brain tumor patient. In many cases, the onset of symptoms such as seizures, unexpected loss of function of a limb(s), problems with speech or changes in vision appear suddenly and diagnosis can be made quickly. In other cases, the symptoms appear gradually and may be initially passed off as minor ailments. Symptoms such as headaches, nausea, vomiting and personality changes are often common to many other conditions, including stress, and make diagnosis more difficult. Once a brain tumor is suspected, further testing is typically ordered. A brain tumor can be diagnosed through various imagining techniques including CT (or CAT) and MRI scans. A computerized axial tomography (CAT) scan uses X-rays to take images of the brain, while a magnetic resonance imaging (MRI) scan uses magnet and radio waves. A CT scan is typically performed first to identify any abnormalities and if one is detected, an MRI scan will provide further detail.
Diagnosing a brain tumor
Brain tumor treatment
Current standard treatments of brain tumors include surgery, radiation therapy and chemotherapy. Depending on the type of tumor and symptoms experienced by the patient, an observational approach is sometimes applied using a series of MRI and CT scans to monitor the tumor for any changes. Treatment plans are individualized to the patient and the type and grade of the brain tumor. Brian tumors in children are different from those in adults and are often treated differently. Although as many as 60% of children with brain tumors will survive, they are often left with long-term side effects.
There are two types of surgery that a brain tumor patient might be offered: biopsy and resection. A biopsy, in which a small amount of the brain tumor tissue is obtained, is used to help determine the type of brain tumor, prognosis and treatment plan. Resection is a form of surgery that aims to remove as much of the brain tumor as possible and is dependent on the location, size and type of tumor, as well as the symptoms of the patient. Age and health will also affect the decision to perform a brain tumor resection. Removing all or part of a brain tumor might help to reduce the patient’s symptoms. During surgery, an ultrasonic aspirator is used to break up the brain tumor using high-frequency sound waves and then the tumor fragments are suctioned away. A laser may also be used during brain tumor resection. Surgery is often followed by radiation therapy and/or chemotherapy.
Radiation therapy involves the administration of high levels of radiation directly at a tumor. Radiation therapy may be used alone or in combination with chemotherapy.
External beam radiation therapy is delivered via machines called linear accelerators (LINAC). The amount of normal tissue within the treatment field is kept to a minimum using precise planning, shields and masks. Radiation is generally given in many doses (fractions) over a period of time and the frequency of each dose, as well as the length of the treatment, may vary depending on the type of tumor and its location in the brain. Generally, a patient can have external beam radiation therapy only once in the same spot and other types of radiation therapies, such as stereotactic radiation, may allow for further radiation in a very focused area.
Stereotactic radiosurgery (SRS) is a specialized radiation technique designed to deliver single, large doses of ionizing radiation to small areas in the brain, significantly reducing exposure to the surrounding brain tissue. This treatment is usually performed using a special metal head frame combined with precision localization of the area to be treated by CT or MRI, followed by delivery of many small, highly focused radiation beams. SRS seems to be most effective in treating small non-malignant tumors in the brain, as well as cancer that has metastasized to the brain. SRS is not appropriate for people with large tumors; tumors that involve many different areas of the brain; tumors that are close to certain structures like the eye or optic nerve; or tumors that are diffuse (spreading within normal brain tissue). Radiosurgery treatments, given over multiple visits, is known as fractionated stereotactic radiosurgery (FSR) and offers precision of SRS for tumors located near critical structures such as the brain stem, optic nerve and acoustic nerve that cannot tolerate high doses of radiation.
Gamma knife is a type of SRS in which the source of radiation is either from a modified linear accelerator or a cobalt-60 (Gamma Knife) machine. The Gamma Knife machine is almost exclusively used to treat brain lesions like brain tumors. This machine uses 201 beams of highly focused gamma rays targeted precisely at the tumor in a single treatment session. The rays are directed through holes of a large helmet attached to the head frame allowing precise targeting to the tumor location. Gamma knife is most frequently used to treat small, non-malignant tumors such as meningiomas, pituitary tumors, acoustic neuromas and secondary tumors. This treatment has not been shown to have a role in the treatment of glial tumors.
Chemotherapy is the use of medications–chemotherapeutic agents or drugs–to stop or slow the growth of tumor cells. Chemotherapeutic drugs are most commonly given orally or intravenously, but may also be given directly intra-arterially, directly into the cerebrospinal fluid (intra-thecal) or via direct anti-tumor therapy. Direct anti-tumor therapy involves the placement of chemotherapeutic agents directly in the area where the tumor was located following tumor resection. One technique of direct anti-tumor therapy uses biodegradable wafers to slowly release a chemotherapeutic drug as they dissolve. Another technique, called convection enhanced drug delivery, uses small catheters that are surgically placed around the tumor cavity and are attached to a pump that can deliver chemotherapeutic drugs directly to the brain. Chemotherapy may be used alone or in combination with radiation therapy.
Temodal is a common oral chemotherapy drug used in combination with radiation therapy to treat adult patients newly diagnosed with glioblastoma multiforme (GBM) and then as maintenance therapy. Temodal alone is used in the treatment of adult patients with recurrent or progressive GBM, or anaplastic astrocytoma after standard therapy. Unfortunately, Temodal is very expensive for the patient if they are not covered by insurance or provincial coverage.
Avastin is the first and only biological treatment approved by Health Canada for recurrent GBM and offers an additional treatment option. Avastin directly targets a brain tumor by controlling its growth and extends survival with only minimal impact on quality of life.
Sides effects
Various side effects are associated with radiation therapy and chemotherapy. Common side effects include nausea, vomiting, hair loss and fatigue. Swelling, headaches and skin irritation are also commonly associated with radiation therapy. Additionally, chemotherapy may cause hearing loss, peripheral neuropathy (numbness, tingling or weakness of the hands and feet) and myelosuppression (low blood count), increasing one’s risk of infection.
Alternative treatments
Alternative treatments for brain cancer, such as viral therapy, immunotherapy and ultrasound therapy, may be under trial or available, depending on where you live. Advancements in technology and scientific research allow for improved imaging techniques, as well as improvements in traditional forms of brain tumor treatment. Additional therapies involving diet, essential oils and even infrared therapy can also have a positive impact on cancer treatment.
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