Some types of brain cancers, known as primary tumors, arise when a particular type of brain cell undergoes transformation and grows and multiplies in abnormal ways, forming a tumor. Other, more common types of brain tumors, known as metastatic tumors, consist of cancerous cells that migrate to the brain from a tumor located elsewhere in the body such as the lungs or the breast. The standard treatments for brain tumors include surgery, radiation therapy, and chemotherapy.
Brain Cancer Treatment Protocols Are Complex
There are more than 120 different types of brain tumors, which make effective treatment complicated. Most metastatic brain tumors are found at more than one location in the brain, adding to the complexity of treatment. The Neurology Channel explains that treatment procedures must be individualized for each patient, and are determined by the patient's age, general health, and the size, location, type, and grade of the tumor. Treatment modalities most often used to treat brain cancer include surgery, radiation, and chemotherapy, often used in combination.
Challenges to Treating Brain Tumors
Several factors make treating brain tumors different from treating tumors in other locations in the body. The intricacy of the brain requires surgical procedures that are much more precise, using highly sophisticated instruments. The brain has a defense mechanism called the blood-brain barrier, which keeps out harmful substances such as bacteria and chemicals. The blood-brain barrier can also prevent some chemotherapy drugs from entering the brain, limiting treatment options.
Surgery is the First Line of Treatment
According to the University of California San Francisco Medical Center, surgery is the preferred treatment of accessible tumors, those that can be removed without damaging vital brain tissue and destroying essential neurological functions. The objective is removal of as much of the tumor as possible, because it is likely to return if any tumor cells remain. Malignant tumors are not confined by distinct borders, and often spread into surrounding normal brain tissue, making complete removal difficult. However, even partial removal offers some benefits.
Radiation Therapy -- Treatment without Opening the Skull
Radiation therapy, or radiotherapy, uses high-energy x-rays or gamma rays to kill tumor cells. It can be used when surgery is not feasible, for treating tumors that cannot be completely removed, or following surgery to prevent the reappearance of a tumor. According to Miles for Hope, conventional radiotherapy, given over a period of several weeks, applies radiation to an entire area of the brain. Stereotactic radiosurgery, on the other hand, enables extremely precise, concentrated delivery to the tumor in a single high dose, minimizing damage to surrounding healthy brain tissue. Interstitial radiation, or brachytherapy, involves placing radioactive seeds directly into a tumor.
Chemotherapy -- Drugs That Kill Cancer Cells
Chemotherapy uses special drugs to poison tumor cells. These drugs impede the normal process of rapid tumor cell division to inhibit tumor growth. Chemotherapy is administered orally or by injection, and may be given alone or in combination with other treatments. According to the National Cancer Institute, treating brain tumors with chemotherapy can be difficult since the brain's blood-brain barrier prevents many therapeutic drugs from entering it. To compensate for this, chemotherapy can also be delivered to the brain through polymer wafer implants, in which biodegradable wafers saturated with a chemotherapy drug are placed directly inside the tumor cavity at the time of surgery. The wafers are left there to dissolve over a short period of time.
