What is radiosurgery?
Radiosurgery is a surgery that uses ionising radiation to destroy precisely selected areas of tissue, usually tumours and cancers. This procedure is specifically called stereotactic radiosurgery.
It usually involves a single treatment of very focused radiation beams (gamma rays, X-rays, or protons) in a focused location without a surgical incision or opening. A 1-session radiation therapy treatment creates a similar result as an actual surgical procedure. However, sometimes it may involve a few treatments.
During radiation therapy, radiation beams are used to damage the DNA of the tumour or other cells so that they no longer reproduce. This causes the tissue of the tumour to die.
What can be treated with radiosurgery?
Stereotactic surgery was originally developed to treat small, deep brain tumours that were hard to reach or extract without substantial damage to the brain and its associated structures.
Now, it may be used for a more comprehensive array of problems in the brain and other parts of the body:
- deep brain tumours
- residual tumour cells after surgery
- pituitary tumours
- cancers of the eye
- arteriovenous malformations, which are tangled blood vessels that leak and disrupt your normal flow
- neurological problems, such as trigeminal neuralgia
- tumours in the lung, liver, abdomen, spine, prostate, head, and neck
- Parkinson’s disease
What are the risks and side effects of radiosurgery?
Radiosurgery is generally less risky than traditional surgery as it avoids complications with anaesthesia, bleeding, and infection due to no incision.
However, it still carries a risk of certain complications, including:
- skin problems, such as red, swollen, peeling, or blistering skin.
- hair loss in the treatment area
- difficulty swallowing
- nausea and vomiting
- swelling, especially of the brain
How is stereotactic radiosurgery done?
Radiosurgery works in the same manner as other types of therapeutic radiology. It distorts or destroys the DNA of tumour cells, causing them to be unable to reproduce and grow. The tumour will shrink in size over time. The blood vessels eventually close off after treatment for blood vessel lesions, like an arteriovenous malformation (AVM).
There are three main types of stereotactic radiosurgery:
- Gamma knife radiosurgery uses specialised equipment to deliver about 200 beams of gamma radiation on a tumour or other target with high accuracy. Each beam has little effect on the brain tissue it passes through; however, the abnormality they are focused on receives a strong dose of radiation.
- Surgery using a linear accelerator machine (also called CyberKnife technology) involves using high-energy X-rays or photons to target large tumours by delivering radiation over several treatments. It uses real-time image guidance and a robot to deliver the therapeutic dose from different angles, increasing the therapy’s precision.
- Proton beam or heavy-charged-particle radiosurgery delivers protons or other heavy-charged particles (like neutrons) to the sites of more minor abnormalities in the brain or throughout the body.
These methods require a lot of CT and MRI imaging to gain precise knowledge of the location and size of the treated abnormality.
During surgery, the patient is awake, however, stays completely still to allow precise delivery of radiation and minimise the effect on normal tissues.