What is stereotactic radiosurgery and how does it work
Stereotactic radiosurgery (SRS) is a highly focused form of radiation treatment used to target selected abnormalities in the brain, spine and other parts of the body. Although its name includes “surgery”, it usually involves no incision, stitches or removal of tissue. Instead, specialised equipment delivers many precisely aimed radiation beams to a defined target.
The treatment is commonly considered for small brain tumours, metastatic cancer deposits, arteriovenous malformations (AVMs), vestibular schwannomas and certain nerve disorders such as trigeminal neuralgia. In carefully selected cases, it may offer an alternative to open surgery or complement surgery, chemotherapy and conventional radiotherapy.
Treatment planning relies on detailed MRI and CT scans, computer modelling and accurate patient positioning. The radiation dose is shaped to affect the target while limiting exposure to nearby healthy brain, spinal cord and other sensitive structures. Suitability depends on the diagnosis, target size, location, symptoms and general health.
For Australians, access may vary between public and private hospitals in Sydney, Melbourne, Brisbane, Perth and other centres. A referral from a GP or specialist is often the first step, while costs, waiting times and private health insurance coverage depend on the facility and treatment plan. A specialist service such as neurosurgical care can help explain how radiosurgery fits alongside other neurological treatments.
How the treatment delivers radiation
SRS uses multiple beams of ionising radiation that converge on a planned target. Each individual beam carries a relatively small amount of radiation through surrounding tissue, while the combined dose at the focal point is high enough to damage the abnormal cells or disrupt the blood vessels supplying an AVM.
Several platforms can deliver this treatment. Gamma Knife systems are designed primarily for intracranial work, while linear accelerator systems, sometimes called LINAC-based SRS, can treat the brain and selected spinal targets. Robotic systems such as CyberKnife may deliver radiation from different angles and can track movement in some treatment settings.
The radiation does not usually destroy a lesion instantly. Tumour cells may lose their ability to divide over weeks or months, and an AVM may gradually close over a longer period. Pain from trigeminal neuralgia can improve sooner, although the timing and durability of benefit differ between patients.
Conditions that may respond to SRS
SRS is often used for small, well-defined brain metastases and some primary brain tumours, including meningiomas and vestibular schwannomas. It can also be considered for pituitary tumours, recurrent disease and selected skull base lesions where conventional surgery could risk important nerves, blood vessels or brain structures.
For an AVM, the aim is to cause gradual scarring and closure of the abnormal vessel connections. For trigeminal neuralgia, a focused dose is directed at the section of the trigeminal nerve involved in transmitting facial pain. Stereotactic body radiotherapy, a closely related approach, may be used for carefully selected spinal or other body lesions.
Large, irregular or poorly defined targets may be less suitable because protecting nearby healthy tissue becomes harder. A lesion causing dangerous pressure, bleeding or hydrocephalus may require urgent surgery or another treatment before radiosurgery is considered.
What happens before and during treatment
Assessment generally includes a neurological examination and high-resolution imaging. MRI is particularly useful for defining soft tissue, while CT can assist with planning and identifying the skull or spinal anatomy. Previous scans, pathology results and other treatments are reviewed by a multidisciplinary team that may include a neurosurgeon, radiation oncologist, neuroradiologist and medical physicist.
On the treatment day, the patient may be fitted with a custom thermoplastic mask or, in some systems, a stereotactic frame. The frame is secured to the skull with small fixation points after local anaesthetic. A mask-based approach avoids pin fixation and is often more comfortable, although the choice depends on the equipment and target.
Treatment may last from several minutes to several hours. Some patients receive one session, while others have staged or fractionated treatment over several days. The patient lies still while the machine delivers radiation, and staff monitor them from an adjacent control room. There is no sensation of the radiation itself, though noise, pressure from the mask or anxiety may be noticeable.
Benefits, risks and recovery
A major benefit is the lack of a large incision and the reduced recovery period compared with craniotomy. Many people return home the same day, although an overnight stay may be recommended. Temporary fatigue, headache, nausea, scalp tenderness or mild swelling can occur, and medication such as corticosteroids may be prescribed if swelling is a concern.
Risks depend heavily on the target’s location and the dose. Radiation can occasionally cause inflammation or oedema, temporary worsening of symptoms, seizures, hearing changes, visual problems or injury to nearby nerves. A delayed reaction called radiation necrosis can produce swelling and may require medication, observation or further treatment. Serious complications are uncommon but should be discussed in detail.
Follow-up usually involves MRI or other imaging at scheduled intervals. A scan soon after treatment may show swelling or apparent enlargement that does not necessarily mean the disease is progressing. Doctors compare scans over time and interpret changes alongside symptoms and the original diagnosis.
How it compares with other treatments
SRS is one option within a broader treatment plan. Open surgery can provide immediate removal or tissue diagnosis and may be essential when a lesion is large or causing pressure. Conventional fractionated radiotherapy spreads treatment over multiple sessions and can be preferable for larger areas or targets close to sensitive structures.
Observation may be appropriate for a small, slow-growing lesion that causes no symptoms. Medicines can control seizures, swelling or nerve pain but may not treat the underlying structural problem. The best choice is shaped by tumour biology, lesion size, previous radiation, age, mobility, personal priorities and the availability of specialist services.
In Australia, patients should ask which technology is available, whether the recommendation is covered under their public hospital pathway or private policy, and how travel will affect follow-up. Radiation services operate under Australian and state or territory safety requirements, with ARPANSA providing national radiation protection guidance and local authorities regulating aspects of clinical practice.
| Treatment approach | Typical role | Recovery and follow-up |
|---|---|---|
| Stereotactic radiosurgery | Small, well-defined brain or selected spinal targets | Often same-day care; imaging follow-up over months |
| Open neurosurgery | Large, accessible or pressure-producing lesions; tissue diagnosis | Longer recovery; hospital stay and wound care |
| Fractionated radiotherapy | Larger regions or targets needing lower doses over several sessions | Repeated visits; fatigue and delayed effects monitored |
| Observation | Slow-growing, symptom-free or uncertain lesions | Regular scans and clinical review |
| Medication | Seizures, swelling, pain or related symptoms | Ongoing monitoring; may accompany another treatment |
The most appropriate path comes from a personalised review of the scans and diagnosis rather than from the treatment name alone. Ask the treating team about the expected goal, alternatives, possible side effects, follow-up schedule and practical arrangements such as driving, work and travel between regional areas and major Australian hospitals.
If you or someone close to you has been referred for focused radiation treatment, arrange a consultation with the relevant neurosurgical and radiation oncology teams. Bring scan reports, imaging discs or digital access details, medication lists and previous treatment records so the team can assess the full clinical picture and develop a safe, coordinated plan.