Stereotactic Radiosurgery and Stereotactic Body Radiotherapy

What is Stereotactic Radiosurgery?

Stereotactic radiosurgery (SRS) is a noninvasive radiation therapy that uses highly focused radiation beams to destroy tumors in the brain, neck, spine, lungs and other parts of the body. Stereotactic body radiotherapy (SBRT) is used to treat tumors in other parts of the body besides the brain and head.

SRS and SRBT are effective at treating very small, well-defined tumors that are difficult to reach and can’t be surgically removed. By delivering high-dose radiation to precise locations, they spare surrounding healthy tissue. For many people, SRS and SBRT are safer and more effective than open surgery.

SRS Technology

Stereotactic radiosurgery doctors use three types of technology to deliver radiation during treatments.

• GammaKnife - an advanced form of radiation therapy that treats brain tumors and other complex conditions with surgical precision
• Linear accelerator (LINAC) - uses X-rays to deliver radiation at cancer tumors with pinpoint accuracy, sparing nearby healthy tissue. Mercy offers the latest generation of LINAC technologies, including CyberKnife. Some locations use the True Beam radiotherapy system, which combines SRS and SBRT in a single delivery system.
• Proton therapy -  a highly specialized, advanced form of radiation therapy that uses high-energy beams of protons to precisely deliver radiation to a tumor, reducing or eliminating unwanted radiation exposure to surrounding, healthy tissue.

How SRS & SRBT Work

Stereotactic Radiosurgery (SRS)

SRS uses high doses of very targeted radiation to destroy tumors in just one treatment session. Several radiation beams reach the tumor at one time, at higher doses than with other radiation techniques. It’s used to treat inoperable tumors in the brain and head without a surgical incision. A radiation oncologist oversees treatment in coordination with a neurosurgeon.

Stereotactic Body Radiotherapy (SBRT)

SBRT, also known as stereotactic ablative body radiotherapy (SABR), delivers high-dose radiation to cancers of the lung, liver, prostate, spine and gastrointestinal system in two to five treatments. It’s ideal for tumors that are hard to reach, prone to movement or next to vital organs. 

Benefits of Stereotactic Radiosurgery

SRS and SBRT offer several advantages, including:

• More accurate radiation delivery
• Higher-dose radiation treatments in fewer sessions (some people need only one round of SRS)
• Multiple radiation beams reach tumors at one time
• Less radiation reaches healthy tissues, reducing side effects

What to Expect From Stereotactic Radiosurgery Treatment

SRS and SBRT are outpatient procedures typically lasting 20 minutes to an hour. Treatment doesn’t need to occur on consecutive days and is usually completed within 10 days. Your SRS treatment plan is tailored to your cancer type and unique needs. Your Mercy care team explains your plan and provides a treatment schedule.

SRS & SBRT Treatment Planning

Planning sessions determine what type and dose of radiation you’ll receive. CT or MRI scans are used to create 3D maps of tumors and determine placement. This allows radiation to be delivered with extreme precision (within a millimeter of its target). Tiny “markers” or seeds may be placed in your body to help your care team quickly locate your tumor. They also ensure your body is positioned correctly during treatment. You may also need to use a custom-fit, molded device to help you remain still during treatment.

During SRS & SBRT Treatment

During SRS and SBRT treatment, you’ll be awake and able to talk to your care team. Treatment length depends on the size and number of tumors being targeted. Your care team monitors you throughout the entire procedure.

Side Effects & Risks of Stereotactic Radiotherapy

SRS and SBRT are noninvasive treatments that pose less risk than traditional open surgery. Side effects from these treatments are usually temporary and may include:

• Overall fatigue
• Tenderness and inflammation at the treatment site
• Nausea or vomiting (if the tumor is near the liver or bowel)

Possible long-term risks include:

• Bone weakness that may lead to breaks
• Damage to healthy cells
• Developing new secondary cancers
• Developing swollen arms and legs (lymphedema)

Mercy offers cancer pain management services with many options for keeping you comfortable, so you can enjoy a better quality of life.