What is stereotactic body radiotherapy?

What are the benefits of Stereotactic body radiotherapy?

• • • Liver
    • Lungs
    • Prostrate
    • Lymph nodes
    • Spinal cord
    • Abdomen

What are the risk factors associated with Stereotactic body radiotherapy?

1. 1. 1. Fatigue and tiredness.
      2. Nausea or vomiting. 

• • • Swelling.

1. 1. 1. Changes in the lungs. 
      2. Weakened bones.
      3. Changes affecting the bowel.
      4. Changes in the spinal cord.
      5. Swollen arms and legs (lymphedema).
      6. Development of new cancer (secondary cancer).

How SBRT Works

• • • All types of stereotactic radiotherapy and radiosurgery work in a similar manner. The specialized equipment focuses a high radiation dose on tumors or other targets. Each beam has a minor effect on the tissue it passes through, but a targeted dose of radiation is released to the site where all the beams interact.
    • The high dose of radiation delivered to the affected area shrinks the tumors and blood vessels to close off over time following treatment. This, therefore, stops the blood supply to the tumor.
    • There is minimal damage to the healthy surrounding tissues.

Preparing for SBRT

• • • The patient may be asked not to eat or drink anything after midnight or the night before the procedure.
    • The patient should ask the doctor if they can take their regular medications the night before or the morning of the procedure.

• • • Jewelry.
    • Contact lenses or eyeglasses. 
    • Dentures. 
    • Makeup, including nail polish.
    • Wigs or hairpieces.

1. 1. 1. Have any implanted medical devices in the body, such as pacemakers, aneurysm clips, artificial heart valves, stents, or neurostimulators.
      2. Carry any of the current medications to the treatment center.
      3. Consult the doctor regarding the medications on the day of the procedures.

The Stereotactic Body Radiotherapy Techniques 

Before the Procedure

• • • Marking. The marking procedure is usually done as an outpatient procedure before SRS treatment. But this step is not needed for most CT-guided technology.
    • Simulation. A radiation oncologist will conduct a simulation. This step ensures the best placement of the body to align it with the radiation beams. An immobilization device will hold the body very tight and still (the patient should inform the doctor if they have claustrophobia). 

• • • With imaging scans and specialized soft waves, the treatment team will arrive at the best combination of radiation beams to target the tumor or other abnormalities.

During the Procedure,

• • • Children are usually given anesthesia for imaging tests and during radiosurgery. Adults are usually awake and may take a mild sedative to calm anxiety.
    • The LINAC machine, during the treatment, delivers radiation beams from different angles to the target. The treatment takes less than 30 – 60 minutes.
    • SBRT can be described as having an X-ray. During the procedure, the patient will not feel the radiation, and the patient will be able to talk with the doctor through a microphone.

After the Procedure,

• • • After the procedure, the doctor will prescribe appropriate medications if the patient complains of any pain or nausea. The patient will be able to eat and drink after the procedure.
    • The patient can return home the same day of the procedure.
    • Patient can resume normal activities within one to two days.

Results

• • • Benign Tumors (including vestibular schwannoma).

• • • Malignant Tumors

FAQ

• How long does it take for Stereotactic radiation to work?

Although the effect of SRS on tumor tissues can be seen a few weeks after the procedure, it may take up to 2 years to see the effect of SRS on an AVM. When SRS is used to treat an AVM, an angiogram is obtained to improve the accuracy of targeting the lesion’s critical portions. 

• What is the success rate of Stereotactic radiosurgery?

SBRT has shown dramatically better outcomes than conventional radiation therapy. Whereas two-year success rates for conventional treatment range from 30 -40 percent, the success rates of SBRT range from 80 – 90 percent, comparable to those of resection surgery but with far fewer risks. 

• How much does Stereotactic radiation therapy cost? 

The median cost of SBRT was $27,145 compared to $17185 for brachytherapy, $37,090 for IMRT, and $54,706 for proton beam therapy (p<0.001).

• How effective is Stereotactic radiosurgery?

Following Stereotactic radiotherapy, the tumor may shrink over 18 – 24 months, but the main goal of the treatment for benign tumors is to prevent any further tumor growth. Malignant tumors may shrink more rapidly, often within a few months.

• How long does fatigue last after SBRT?

The patient may develop fatigue 4-6 weeks after the treatment. The fatigue can range from mild to severe. It may last for several months after the treatment ends.  

• What are the types of Stereotactic radiosurgery? 

There are two types of stereotactic radiosurgery the doctor uses to deliver radiations. They are:

1. Linear accelerator (LINAC)- LINAC machines use x-rays to treat cancerous and non-cancerous abnormalities in the brain and other body parts.  

Picture Courtesy: mayoclinic

2. Proton beam (charged particle) is the newest type of stereotactic radiotherapy found in only a few research centers in the USA. It can use fractionated stereotactic radiotherapy to treat body tumors over several sessions. 

Picture Courtesy: Onco.com