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If you have prostate cancer and radiation therapy is an option, how to choose which type is right for your situation? The answer lies in a discussion with your doctor about the pluses and minuses of each.

Radiation therapy for prostate cancer has advanced substantially in recent years to become both more precise and safer. Radiation therapy may be a particularly good option, with results as good as surgery, for those who have a slower-growing cancer.

Radiation therapy uses high-energy rays or particles to kill cancer cells. Depending on the stage of the prostate cancer and other factors, radiation therapy might be used as the first treatment for cancer contained within the prostate gland; along with hormone therapy for cancer outside the prostate; if cancer recurs after prostate cancer surgery; or for advanced cancer to help prevent or relieve symptoms.

To determine the most appropriate radiation approach, your doctor will consider your age, comorbidities, history of urinary or gastrointestinal symptoms or risk factors, and the size of your prostate, as well as the stage and grade of the prostate cancer. Prostate cancer specialists also take into account your prostate-specific antigen (PSA) level, the Gleason score of your prostate biopsy, and the appearance of the prostate on an MRI exam.

"There are now many viable radiation approaches and the decision making has become very personalized," said Jonathan E. Leeman, MD, of Dana-Farber Cancer Institute and Harvard Medical School in Boston.

External Beam Radiation Therapy (EBRT)

This type of radiation therapy directs radiation beams from outside the body to designated locations of the tumor within the prostate. EBRT can be used to cure earlier-stage cancers, or to help relieve symptoms such as bone pain if the cancer has spread to a specific area of bone. Treatments typically are given for 5 days a week in an outpatient center for several weeks.

EBRT has replaced conventional radiation therapy because it delivers more doses of radiation per treatment, allowing patients to return to their life sooner.

Intensity Modulated Radiation Therapy (IMRT)

This is the most common type of EBRT for prostate cancer. The treatment involves use of a computer console that moves around the patient as it delivers radiation. Some newer radiation machines have imaging scanners that deliver image-guided radiation therapy.

Stereotactic Body Radiation Therapy

This type of radiation therapy uses advanced image-guided techniques to deliver large doses of radiation to a precise area in the prostate. Because there are large doses of radiation in each dose, the entire course of treatment is much shorter. This allows patients to receive the full course of therapy in only five treatments over 10 days.

Brachytherapy

This type, also known as seed implantation or interstitial radiation therapy, uses small radioactive pellets placed directly into the prostate. Imaging tests, such as transrectal ultrasound, CT scans, or MRI, are used to help guide the placement of the radioactive pellets, and computer programs calculate the exact dose of radiation needed. Brachytherapy is typically used for early-stage prostate cancer that is relatively low-grade, or combined with EBRT when there is a higher risk of the cancer growing outside the prostate.

If you have a rising PSA level after prostate cancer surgery, you may require radiation therapy. The goal is to reduce the risk or eliminate a recurrence of cancer in the prostate. This treatment is given 5 days a week for approximately 7 weeks. The planning process is similar to IMRT.

The decision for which method to choose typically comes down to the side effects of each approach and the potential impact on quality of life. If you are diagnosed with prostate cancer, consult both a radiation oncologist to learn about the radiotherapy options, as well as a surgeon about whether you are a candidate for surgery.

Read previous installments in this series:

For Your Patients: Risk Factors, Signs, and Symptoms of Prostate Cancer

For Your Patients: How Will My Doctor Diagnose Prostate Cancer?

For Your Patients: How to Talk to Your Doctor About Whether You Need a PSA Test

For Your Patients: What Are Your Options for Prostate Cancer Treatment?

"Medical Journeys" is a set of clinical resources reviewed by physicians, meant for the medical team as well as the patients they serve. Each episode of this journey through a disease state contains both a physician guide and a downloadable/printable patient resource. "Medical Journeys" chart a path each step of the way for physicians and patients and provide continual resources and support, as the caregiver team navigates the course of a disease.