Stereotactic Radiosurgery

Stereotactic radiosurgery (SRS) is a non-surgical radiation therapy used to treat functional abnormalities and small tumors of the brain. It is a highly precise form of radiation therapy that uses multiple beams of radiation converging in a small area, delivering a high dose of radiation to the targeted tissue while minimizing exposure to surrounding healthy tissues.

History

Stereotactic radiosurgery was first developed in the 1950s by Swedish neurosurgeon Lars Leksell. The initial technique used proton beams and was later modified to use gamma rays, which are still used today in some forms of SRS.

Procedure

The SRS procedure typically involves the following steps:

• A thorough evaluation by a multidisciplinary team of radiation oncologists, neurosurgeons, and other medical professionals to determine if SRS is an appropriate treatment option.
• Imaging studies such as MRI or CT scans are performed to precisely locate the tumor or abnormality and plan the treatment.
• A stereotactic head frame or mask is used to immobilize the patient's head during the procedure, ensuring accurate targeting of the radiation beams.
• The patient lies on a table that slides into a machine called a linear accelerator (linac), which delivers the radiation beams.
• Multiple beams of radiation are delivered from different angles, converging at the targeted tissue to deliver a high dose of radiation while minimizing exposure to surrounding healthy tissues.

Types of SRS

There are several types of SRS, including:

• Gamma Knife: uses gamma rays emitted by cobalt-60 sources.
• Linear Accelerator (Linac): uses x-rays produced by a linac to deliver radiation beams.
• CyberKnife: uses a robotic arm to move the linac and deliver radiation beams from different angles.

Indications

SRS is used to treat various conditions, including:

• Brain tumors (e.g., metastases, meningiomas, acoustic neuromas).
• Vascular malformations (e.g., arteriovenous malformations).
• Functional disorders (e.g., trigeminal neuralgia, epilepsy).

Risks and Side Effects

While SRS is generally well-tolerated, potential risks and side effects include:

• Fatigue.
• Nausea and vomiting.
• Headache.
• Seizures (rarely).
• Radiation necrosis (tissue damage due to radiation, which can occur months or years after treatment).

Outcomes

The effectiveness of SRS varies depending on the condition being treated and individual patient factors. In general, SRS has been shown to be effective in:

• Controlling tumor growth.
• Relieving symptoms (e.g., pain, seizures).
• Improving quality of life.

Follow-up Care

After SRS, patients typically require regular follow-up appointments with their radiation oncologist and other healthcare providers to monitor the effectiveness of treatment and manage any potential side effects or complications.

Frequently Asked Questions (FAQs)

What is Stereotactic Radiosurgery?
A non-surgical procedure using radiation to treat tumors and lesions.

How does it work?
Delivers high doses of radiation to specific areas with minimal damage to surrounding tissue.

What conditions can it treat?
Brain tumors, arteriovenous malformations, and trigeminal neuralgia.

Is it painful?
Typically painless, but may cause mild discomfort during treatment.

How long does the procedure take?
Usually 1-2 hours, depending on the complexity of the case.

Is anesthesia required?
Sometimes, but often performed under local anesthesia or sedation.

What are the benefits?
Minimally invasive, reduced risk of complications, and faster recovery.

Are multiple sessions needed?
Sometimes, but often a single session is sufficient.

Can it be used for other parts of the body?
Yes, also used to treat spinal and lung tumors.

How soon can normal activities resume?
Usually within a few days after treatment.