Gamma knife radiosurgery is a form of stereotactic radiotherapy (SRT) used as a non-invasive treatment for a variety of brain conditions. During this treatment, about 200 beams of radiation are aimed from points surrounding the head to converge onto a single predetermined location inside the brain. Each beam carries a small amount of radiation through the brain, minimizing damage to surrounding healthy tissue while creating a concentrated source of radiation at the point where all the beams converge. This surgery has many advantages over traditional brain surgery and has limited side effects.
The first step in gamma knife radiosurgery is to anesthetize the patient’s scalp in preparation for the placement of a stereotactic frame onto her head with screws. A magnetic resonance image is then taken of the head with the frame in place in order to calibrate the frame’s position in relation to the target of the radiation. The patient is then transported to the gamma knife radiosurgery clinic where doctors, and often a physicist, work to prepare the treatment protocol. The medical procedure typically lasts up to one hour, and often only one treatment is necessary. Following treatment, the frame is removed and the patient is either allowed to go home or is kept overnight for observation.
Many conditions can be treated with gamma knife radiosurgery. Both benign and malignant brain tumors are destroyed using this technique by damaging the tumor cells’ deoxyribonucleic acid (DNA), which prevents the tumor from growing and gradually causes it to shrink. Arteriovenous malformation is characterized by irregular cortical arteries and veins that produce abnormal bleeding, seizures, and headaches. This condition is relieved by using gamma knife radiosurgery to thicken the walls of the abnormal blood vessels until they are blocked. Trigeminal neuralgia is a condition where the nerves in the brain send pain signals to the facial area, and is eliminated by using SRT to destroying these nerves.
There are several benefits to gamma knife radiosurgery over standard brain surgery. Traditional brain surgery requires opening the skull, gaining access to and precisely locating the damaged area inside the homogeneous brain tissue, treating the problem without damaging surrounding areas, and re-establishing the skull bone. The risk off peripheral damage, infection, and a prolonged hospital stay make this type of surgery a risky and expensive procedure. Gamma knife radiosurgery precisely targets the damaged area or tumor, minimizes or completely eliminates the danger of peripheral damage, significantly curtails any risk of infection, takes no longer than one hour, usually only needs one treatment, and either requires no hospital stay or one night in the hospital.
Despite the many benefits, there are a few side-effects to this form of treatment. The most serious side effect is swelling of the brain tissue near the treatment point, causing nausea, vomiting, and headaches. Feeling abnormally tired is a common side effect of most radiation treatments. Scalp pain or irritation where the frame was anchored to the head is also common. Short-term hair loss can occur as well, but is rare.