Radiation therapy uses focused beams of intense energy to destroy cancer cells and shrink or control the growth of tumors. Radiation therapy works by preventing targeted cells from multiplying. The objective of radiation therapy is to destroy the harmful cells while minimizing damage to healthy cells.
Radiosurgery is a form of radiation therapy that uses precisely targeted radiation to destroy tumors. Radiosurgery is non-invasive – there is no cutting involved. The term “surgery” refers to the high level of precision of the energy beams. Stereotactic body radiation therapy (SBRT) is a treatment that uses precisely targeted radiation to destroy tumors located outside the brain and spine.
The CyberKnife System is a unique, robotic system designed to deliver high-precision radiosurgical and SBRT procedures.
Fiducial markers are tiny metal objects (about the size of a grain of rice) that allow your doctors to line up the beams of radiation to make sure that your radiation therapy is delivered exactly the same way and in the same place each time. This helps them to target the tumor and avoid your healthy tissue.
The marker seeds are made of gold or platinum and will stay in the prostate permanently. They are smaller than a grain of rice and leaving the marker seeds in the prostate gland will not hurt or harm your body in any way.
Why this procedure?
To improve the accuracy of your radiotherapy treatment we are introducing a new procedure called Stereotactic body radiation therapy (SBRT) with fiducial markers (gold seeds) for prostate cancer.
This involves the insertion of very small gold seeds into the prostate gland. Each day when you have your radiotherapy treatment, these seeds are identified using a variety of imaging techniques. We can track the seeds movement, and therefore the movement of the prostate gland. This allows the radiographers treating you to position the radiotherapy beams accurately onto the prostate gland, by making small adjustments to the radiotherapy treatment couch before every treatment.
What is the procedure?
An ultrasound probe is covered in gel and inserted into your back passage to create an image of the prostate, allowing the seeds to be inserted into the different areas of the prostate with great accuracy.
Three marker seeds will then be placed within the prostate through ultrasound based needle guidance. The seeds are NOT placed through the rectum, but through the skin on the outside of your body between the scrotum and the rectum (the perineum). There may also be a brief, sharp pain as the needle is inserted into the prostate gland.
Before, during and after the procedure
This procedure is very well tolerated in the majority of men. About 1/3rd of patients will develop a temporary symptom that they did not have prior to this procedure with the most common being:
• increased urinary frequency
• small amounts of blood in the urine
• slight burning with urination
• blood in the ejaculate
In about majority of the cases these symptoms will subside within 2 weeks. There is a very low risk of a significant side effect such as an infection that could lead to sepsis (an infection that enters your bloodstream).