Dictionary

Sstereotactic needle biopsy A needle biopsy accomplished withstereotactic guidance systems — a combination of computersand MRI or CT scanning equipment.stereotactic radiosurgery [steh ree o tak´tik] A special, focalform of radiation therapy that uses a large number of narrow,precisely aimed, high dose beams of ionizing radiation. Thebeams are aimed from many directions circling the head, andmeet at a specific point: the tumor. The treatment is deliveredin one session. Stereotactic radiotherapy or fractionatedstereotactic radiosurgery is stereotactic radiosurgery deliveredin multiple fractions over a period of time. Commonlyabbreviated SRS.stereotactic radiotherapy [steh ree o tak´ tik] A radiationtherapy technique that uses a large number of narrow, preciselyaimed, highly focused beams of ionizing radiation, delivered individed doses over a period of time (fractionated). The beamsare aimed from many directions circling the head, and meet ata specific point. Stereotactic radiotherapy is abbreviated SRT.stereotactic surgery The use of computers to create a threedimensional image is called stereotaxy. Its purpose is to provideprecise information about a tumor’s location and its positionrelative to the many structures in the brain. Stereotaxy canbe used by the surgeon to map out the surgical procedurebeforehand and “rehearse” or during the surgery itself.stereotaxic biopsy A computer guided needle biopsy. A needlebiopsy is performed by making an incision in the skin and thendrilling a small hole into the skull. A narrow, hollow needle isinserted through the hole and into the tumor. A small amountof tumor is drawn up into the needle. Also called a stereotacticneedle biopsy.steroids [stair´ oidz] Medications used to decrease swelling andinflammation around tumors. Also called glucocorticosteroidsor corticosteroids.stomatitis [sto ma tie´ tus] Inflammation of the cells(mucous membrane) lining the mouth, a possible side-effectof chemotherapy. One form of mucositis.STR Subtotal resection.strabismus [strah biz´ mus] Imperfect eye coordination(crossed eyes) due to an eye muscle imbalance.stratify Grouped by like characteristics. In a clinical trial,patients are stratified into sub-groups so that more accuratecomparisons can be made. For example, astrocytoma patientsmight be stratified by the grade of their tumor or the extent oftheir resection.study arm One of the treatments offered in a clinical trial.Also called arm, treatment arm.subarachnoid space [sub ah rack´ noyd] The space betweenthe arachnoid and the pia mater membranes of the meningesthrough which cerebrospinal fluid flows.subcutaneous [sub cue tay´ nee us] Beneath the skin.subependymal giant cell astrocytoma[sub ep en´ dih mul • as tro sigh toe´ ma] A grade Iastrocytoma, it is the ventricular tumor associated withtuberous sclerosis.subependymoma [sub ep en dih mow´ ma] A grade I, benigntumor that most often arises in the 4th ventricle or one of thelateral ventricles.suicide gene Carried to the tumor by a harmless virus, the genechanges the tumor’s genetic structure slightly so that a uniqueprotein is produced. An anti-viral drug is then given whichconverts the protein into a toxin that kills the tumor cells.S112113