Stereotactic radiosurgery and radiotherapy


 

Stereotactic radiosurgery (SRS) is an advanced technique which treats brain and spine tumours (and other conditions) with the delivery of large doses of precisely focused beams of radiation.


Treatment may be completed in one session, often taking less than an hour. Sometimes, depending on the size and location of the tumour, we need to give multiple treatments, up to five times per week. In this case the technique is known as stereotactic radiotherapy (SRT).



How does stereotactic radiosurgery work?


Stereotactic Radiosurgery (as well as SRT) is non invasive and generally done as an outpatient, without the need to be admitted to hospital. This accurate delivery of a highly concentrated dose of radiation does not require an anaesthetic or an incision, and is often an alternative to more traditional ‘open’ surgery.

 

Stereotactic Radiosurgery is generally administered by a team, with members including a radiation oncologist, neurosurgeon, physicist, radiotherapist, and nurse, amongst others. The aim of treatment is to inactivate or destroy the tumour (or other abnormality which is being treated), whilst sparing or minimising impact on the surrounding normal brain or spinal tissue. This is done by utilising state-of-the art radiotherapy technology, together with advanced 3D navigation software.

 

Stereotactic Radiosurgery uses higher doses of radiation, administered to a precisely located area within the brain or body with sub millimeter accuracy. With this extremely high level of accuracy, larger doses of radiation can be delivered to patients with minimal impact on surrounding healthy tissue. This means that patients can complete their treatment with less visits to the hospital, while receiving higher and more effective doses of radiation while protecting surrounding healthy tissues.



State of the art technology

 

Stereotactic Radiosurgery at Epworth Radiation Oncology uses state of the art technology:

  • New Novalis Tx linear accelerator (the first in a not for profit private hospital in Australia)

  • This powerful radiosurgery system offers advanced technology for non invasive treatment of tumours and other conditions

  • Technology allows localisation of tumours with sub millimeter accuracy

  • Offers a high dose rate. Thus treatment is delivered faster, easier for patient, less chance of patient movement

  • High Definition micro multileaf collimators allows us to shape the radiation dose to the shape of the target, producing highly precise dose sculpting for optimal normal healthy tissue sparing

  • Room based ExacTrac imaging provides continual imaging during treatment to detect movement

  • A robotic 6D couch which corrects in six dimensions instead of the standard three dimensions

 

Cranial Radiosurgery at Epworth Radiation Oncology uses a frameless system to treat the patient. High level of accuracy is achieved with the combination of a customised mask and image guidance. The patient will have this mask made at their planning CT and treatment.

  

Compared to traditional whole brain radiation (WBRT) which gives the same radiation dose to healthy normal brain, with Stereotactic Radiosurgery:

  • Only the tumour is targeted. Healthy parts of the brain are not affected by the radiation
  • Less possibility of adverse intellectual function

  • Less loss of hair

  • Less side effects, such as headaches

  • Better quality of life

 



What conditions can stereotactic radiosurgery (and stereotactic radiotherapy) treat?

  

They are used to treat a variety of malignant (cancerous) and benign tumours of the brain and spine, as well as other conditions such as vascular malformations (AVMs), facial pain (trigeminal neuralgia), and movement disorders (tremor and Parkinson’s disease).

 

A list of conditions which may be treatable with stereotactic radiosurgery is listed below. In general, this is only suitable for tumours or vascular malformations of less than 3.5cm diameter. A number of other factors also determine whether a particular condition can be treated with SRS, and you should discuss your specific situation with a neurosurgeon and / or radiation oncologist who specialises in stereotactic radiosurgery.

 

Tumours with SRS

  • Brain metastases

  • Recurrent brain tumours 

  • Meningiomas

  • Acoustic neuromas (vestibular schwannomas)

  • Chordomas

  • Pineal Tumours

  • Pituitary adenomas

  • Gliomas (glioblastoma multiforme)

  • Spine metastases

  • Other metastases

 

The concentrated radiotherapy in SRS damages the tumour’s genetic material (DNA), reducing the ability of tumour cells to replicate and therefore the ability of the tumour to grow. As a result of this process, malignant tumours (with high cell reproduction) often shrink within two or three months, and benign tumours (such as meningiomas) may shrink more slowly (over one to two years).

 

Other conditions treated with SRS

  • Vascular malformations (Arteriovenous malformations or AVMs, and arteriovenous fistulas or AVFs)

  • Trigemminal neuralgia

  • Movement disorders

  • Parkinson’s disease

  • Essential tremors