The treatment of brain tumors often requires combinations of several types of treatments to effectively fight the disease.
For solitary tumors that are not near the brain’s most critical structures, such as those involved in vision or regulation of breathing, the most common treatment option is surgery, in which the tumor is cut out through surgery.5 Surgery is used for primary brain tumors, such as a GBM, as well as solitary brain metastases and benign tumors. Surgery is often followed by whole brain radiation therapy or partial brain radiation techniques to eliminate any microscopic bits of the tumor. In some cases, malignant brain tumors can be treated in combination with chemotherapy for greater effect.
If the patient suffers from multiple tumors, as is often the case with metastatic brain cancer, treatment is often whole brain radiation therapy. Whole brain radiation treatment typically requires 20 to 40 sessions over four to six weeks and is used to treat the entire brain, including both the tumor(s) and normal tissue. The normal brain tissue is not as susceptible to small doses of radiation as the tumor cells, so the extended courses of whole brain radiation therapy result in minimal destruction of normal brain cells for the patient.
For patients with a limited number of tumors in their brain, radiosurgery is another option.6
Chemotherapy medication is delivered orally or through an IV. It affects both normal tissue and the cancer cells, so patients may experience side effects, such as severe nausea and vomiting, infections, fatigue and weight loss. Chemotherapy is typically given to a patient in combination with other types of brain cancer treatment. For example, it may be given after whole brain radiation therapy to target both the metastatic tumors in the brain and the tissues outside the brain that originally produced the cancer cells.
During the last 25 to 30 years, radiosurgery has emerged as an alternative to surgery.7-9 Unlike conventional radiation therapy, during which small doses of radiation are delivered over weeks and months, radiosurgery can treat a tumor in one to five sessions by delivering a high dose of radiation with extreme accuracy. During radiosurgery, hundreds of narrow radiation beams are delivered from different angles, all intersecting at the tumor. This treatment allows the tumor to be attacked by a high dose of radiation without damaging surrounding sensitive brain tissue. To be effective and safe, radiosurgery must be accurate. To achieve this accuracy, some radiosurgery devices, such as the Gamma Knife®, require a rigid stereotactic frame be affixed to a patient’s head so the system can pinpoint the exact location of a tumor.8 These frames are screwed into a patient’s skull after local anesthesia is given. Many patients find these frames to be uncomfortable and painful. In addition, if multiple treatment sessions are required, the patient may have to be hospitalized with the frame in place for several days until the treatment is complete.
Other radiosurgery devices, such as the CyberKnife Robotic Radiosurgery System, improve on other radiosurgery techniques by eliminating the need for stereotactic frames. As a result, the CyberKnife System enables doctors to achieve a high level of accuracy in a non-invasive manner and allows patients to be treated on an outpatient basis.10, 11