SRS and SBRT are highly focused forms of radiotherapy. SRS is stereotactic radiosurgery, usually used in the brain. SBRT is stereotactic body radiotherapy, used outside the brain.
Despite the word "surgery," SRS does not involve a cut. It is radiation treatment given with very high accuracy.
Common Indications for SRS and SBRT
Your doctor may consider SRS or SBRT for:
- Small brain tumours.
- Cancer that has spread to the brain.
- Small lung tumours in selected patients.
- Cancer spread to bone or spine in selected cases.
- Liver or adrenal targets in selected cases.
- Re-treatment where normal tissue dose must be tightly controlled.
What exactly do SRS and SBRT treat?
They treat small, clearly mapped targets. Because the dose per session is high, the team must be confident about the target position and nearby sensitive structures.
How should I prepare?
You will have detailed planning. This may include CT, MRI, PET-CT, a mask, body frame, or other supports. Follow instructions closely because setup accuracy matters.
Do I need to stop taking medication?
Do not stop medication unless your doctor tells you to. If you take steroids, seizure medicines, blood thinners, or diabetes medicine, make sure the team knows.
What happens when I arrive?
The team positions you carefully and checks your setup with imaging. You may be on the couch longer than for simpler radiotherapy because the checks are more detailed.
How is the treatment performed?
The machine sends radiation to the target from many angles. You stay still while the machine moves around you.
How long does it take?
Some sessions take 30 minutes or less. Others take longer, depending on the target and machine.
Is there any discomfort?
The radiation does not hurt. A tight mask, frame, or long treatment position can feel uncomfortable. Tell the team if you feel panicky or in pain.
Are there risks?
Yes. Because the dose is strong, side effects can be serious if nearby sensitive tissue is affected. Risks depend on the target, such as swelling after brain treatment or soreness after body treatment.
Is SRS brain surgery?
No. It is called radiosurgery because it treats a small target very precisely, not because a surgeon opens the skull.
Can I have SRS or SBRT if I am pregnant?
Pregnancy Precaution
Tell your doctor or radiotherapy team if you are pregnant or think you might be. SRS and SBRT use high-dose radiation, so pregnancy must be reviewed before treatment.
When should I seek urgent help?
Warning signs depend on the treatment site. Seek urgent assessment for a seizure, new weakness or confusion, severe breathing difficulty, coughing significant blood, sudden severe pain, or loss of bladder or bowel control. Ask for written site-specific instructions before leaving.
Sources and further reading
- National Cancer Institute: External Beam Radiation Therapy, including SRS and SBRT
- National Cancer Institute: Radiation Therapy Side Effects
Conclusion
SRS and SBRT are precise treatments for carefully selected targets. Ask your team what body part is being treated, how many sessions are planned, and what symptoms should make you call after treatment.