What is Radiation Therapy?
Radiation therapy uses high-energy rays to kill cancer cells. Radiation can be used as primary treatment for prostate cancer (in place of surgery). It can also be used after surgery if the cancer is not completely removed or if it returns. Imaging tests are run to find the exact location of the tumor. There are two kinds of radiation therapy:
External Beam Radiotherapy
Patient Receiving External Radiation
External beam radiation therapy (EBRT) sends a targeted beam of radiation to the prostate. Before the first treatment, your medical team will take detailed images of your prostate. This will help them to know how much radiation is needed and where to target it. Your medical team will work to limit the radiation to your organs, such as the bladder and rectum, which is not affected by the cancer. A small amount of radiation is delivered in daily doses outside of the body to the prostate, over 7 to 8 weeks. Your health care provider may use three dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT).
Prostate Brachytherapy (Internal Radiation Therapy)
Low dose rate (LDR) brachytherapy
High Dose Rate (HDR) Brachytherapy
With brachytherapy, radioactive material is placed into the prostate using needles or a catheter. There are two types of brachytherapy: low dose rate (LDR) brachytherapy and high dose rate (HDR) brachytherapy.
LDR brachytherapy - is when your doctor uses a needle to insert radioactive "seeds" about the size of a rice grain into the prostate. These seeds send out radiation, killing the prostate cancer cells nearby. In LDR, the seeds are left in the prostate even after treatment is finished.
HDR brachytherapy - is when your doctor will insert radiation into your prostate using a catheter. This catheter may remain in your body until treatment is complete. But the radiation source is only inserted in your prostate temporarily. Once your treatment is finished, all radioactive material is removed.
Surgery and anesthesia are required for both LDR and HDR brachytherapy. In addition you may need to stay in the hospital overnight to complete your treatment.
What are the Benefits, Risks and Side Effects of Radiation Therapy?
The benefit of radiation therapy is that it is less invasive than surgery. Both types of radiation are effective for early stage prostate cancer. You may need to get the two types of radiation combined. If you have advanced or aggressive cancer, hormone therapy is added to improve cancer control.
One disadvantage of radiation therapy is that it leaves the prostate in the body. If you choose this treatment you are at higher risk of the cancer coming back.
The main side effects of radiotherapy are incontinence and bowel problems. Erectile dysfunction (ED) is also common. ED appears to get worse with time. Modern radiation causes less harm to normal tissues. Long-term effects to normal tissues are unknown.
Who are Good Candidates for Radiation Therapy?
Radiation therapy can be a good choice for you if:
- The prostate cancer is only in the prostate
- The prostate cancer has spread to organs and tissue near the prostate and you are using hormone therapy
- The prostate cancer has returned after treatment
- You want to reduce the symptoms of advanced prostate cancer