Stereotactic RadioSurgery & RadioTherapy (SRS/ SRT)

What is SRS/SRT?

Non-invasive advanced radiation therapy used to treat functional abnormalities and small tumours of the brain

Stereotactic radiosurgery (SRS)/Stereotactic radiotherapy (SRT) is a non-invasive advanced radiation therapy used to treat functional abnormalities and small tumours of the brain. SRS/SRT requires a stereotactic immobilization system to maintain the patient position to ensure precision and accuracy. SRS/SRT relies on advanced imaging technologies to map your tumour on simulation and to verify its position prior to treatment.

SRS allows the delivery of high doses of radiation to a small target over a short period of time. SRT is very similar to SRS but SRT is instead fractionated to smaller radiation doses over longer period of time.

Which type of diseases can be treated with SRS?

At Mount Miriam Cancer Hospital, SRS is usually used to treat benign tumours such as acoustic neuroma, meningioma and pituitary tumours; SRS is also used to treat malignant tumours such as brain metastases, retreatment of intracranial recurrence and residual brain tumours post surgery.

How is SRS given? And, what to expect?

Firstly, you will need an initial Computed Tomography (CT) scan. You will be comfortably positioned on the CT table by the Radiation Therapists with stereotactic immobilizing system and associated accessories to maintain your head in a very stable position. This is a painless procedure. You must lie still during CT Simulation so that the position is reproducible and good CT scan quality is obtained.

The CT simulation scan will be complemented with the Magnetic Resonance Imaging (MRI) scans to map your tumour in 3D. A team of Clinical Oncologists and Medical Physicists will use sophisticated computer programmes to define the tumour target and optimize the radiation delivery directly to the tumour while minimizing doses to the normal healthy tissues around the tumour.

On the treatment day, you will be positioned by the Radiation Therapists on the treatment table with exact reproduction of the setup during CT simulation. You are required to lie still and adhere to the instructions given to you by the Radiation Therapists. Your position will be verified by the CT imaging equipped on our treatment system.

The treatment session generally lasts for about 20 minutes to 40minutes, and the procedure is painless. You will be monitored at all times from the operator station through closed circuit televisions (CCTVs) fixed around the treatment room.

What are the advantages of SRS?

SRS is a non invasive and painless procedure. It allows us to treat areas which are inaccessible by surgery or close to organs at risk.

The system allows delivery of high doses of radiation to a precise location to improve treatment outcomes and to minimise injuries to surrounding structures. It is a convenient treatment as it does not require invasive procedures or hospitalization. It is also done over a short period of time compared to the conventional radiation techniques.

In certain situations where not much alternatives are available, SRS allows the ‘retreatment’ of certain brain lesions which recurred despite previous treatments.