One of the most common neurosurgical procedures, the usual method of removing a brain tumor after it has been diagnosed and located is a procedure called a craniotomy . The entire head is shaved and cleaned to eliminate the possibility that a stray bit of hair might fall into the incision that is made in the scalp. After the scalp has been opened, a series of holes are drilled in a pattern outlining the working area for the surgeon; a wire saw is used to cut the skull between the drilled holes.
Removing the tumor is a delicate operation, not only because of the need to avoid damage to healthy brain tissue but because accidental severing of a blood vessel in the brain could produce a critical hemorrhage. The surgeon tries to remove the entire tumor, or as much of the tumor as appears possible without damaging vital brain tissues or blood vessels. All the various types of brain tumors are considered dangerous, whether malignant or benign, because within the rigid confines of the skull there is no opportunity for outward release of pressure. Therefore any growth may compress or destroy vital brain tissues if left untreated.
After the tumor is removed, the piece of skull removed at the start of the operation is replaced and the scalp flap is sewed in place. Radiation therapy may be administered for a month to six weeks after surgery to destroy any tumor tissue left behind or tumor cells that may have drifted into the spinal canal. Some tumors near the base of the brain may be treated effectively with radiation alone if the tumor cells are radiosensitive. Tumors of the pineal gland and the pituitary gland also may be treated with radiation.