Stereotactic Radiosurgery

No. Despite the name, SRS does not involve any incision, no opening in the skull, and nothing is physically removed. It uses many focused radiation beams that meet at the tumor to deliver a high, precise dose. The word surgery refers to the precision of the targeting, not to cutting. There is no wound to heal afterward.

The radiation itself is not felt and causes no pain during treatment. If a head frame is used, a local numbing injection is given at the pin sites, and the brief sting of that injection is usually the only discomfort. Some people feel pressure when the frame is placed. Mask-based treatment involves no pins at all.

Many tumors are treated in a single session. Some are treated across two to five sessions, an approach called fractionated stereotactic radiotherapy, which spreads the dose out to let healthy tissue recover between treatments. The number of sessions depends on the size, location, and type of tumor, and is decided during planning.

SRS focuses high-dose radiation on specific targets while sparing most of the brain. Whole-brain radiation treats the entire brain at a lower dose over several sessions. SRS is now standard for a limited number of metastases because it spares healthy tissue. Whole-brain radiation is still used in certain situations, such as widespread disease that cannot be managed with focused treatment alone.

Short-term effects are usually mild and include tiredness, headache, nausea, and scalp tenderness at any pin sites. Over the following weeks the treated area can swell, sometimes requiring steroids. A delayed risk is radiation necrosis, in which treated tissue breaks down months later. Risks rise with larger treated volumes and prior radiation. Outcomes vary by tumor and cannot be promised.

These are brand names for different SRS platforms. Gamma Knife uses fixed gamma-ray beams focused inside the brain. CyberKnife and similar systems use a moving linear accelerator that produces X-ray beams. Rutgers Cancer Institute and Robert Wood Johnson University Hospital in New Brunswick offer Gamma Knife radiosurgery for tumors in the brain.

Generally no. SRS is best suited to smaller, well-defined tumors, often under about three centimeters. Large tumors are harder to treat safely because the dose must cover more tissue, and the risk of side effects rises with size. A large tumor pressing on the brain often needs surgery to relieve that pressure, since radiation works gradually rather than removing bulk.

In most cases, no. SRS is typically an outpatient procedure. Patients usually spend most of the treatment day at the center for imaging, planning, and delivery, then go home the same day. Most people resume usual activities within one to two days. A small number of situations may call for overnight observation.

Response is tracked with follow-up imaging over the months after treatment, often starting around three and six months. SRS works gradually, so a tumor may shrink slowly or simply stop growing, and a stable scan can indicate the treatment is controlling the tumor. Because radiation necrosis can resemble regrowth on scans, follow-up is interpreted carefully over time.