Radiation Therapy for Prostate Cancer
- Facts About Prostate Cancer
- Risk Factors For Prostate Cancer
- Screening For Prostate Cancer
- Diagnosing Prostate Cancer
- Treatments for Prostate Cancer
- External Beam Radiotherapy
- Proton Beam Therapy
- Hormone Therapy
Prostate cancer is the most common malignancy in American men.
- In 2003, more than 220,000 men were diagnosed as having prostate cancer, making it the number one type of cancer in men.
- Nearly 29,000 men died from prostate cancer in 2003.
- More than 75 percent of prostate cancer is diagnosed in men over age 65.
Incidence of prostate cancer increases with age.
- Median age at diagnosis in Caucasian males is 71.
- African-American men have the highest incidence of prostate cancer in the world.
- Heredity accounts for 5 to 10 percent of cases.
According to the American Cancer Society, men aged 50 or older should be offered a digital rectal exam (DRE) and a PSA blood test. However, it is a good idea to visit your doctor earlier to establish a baseline PSA level so you can monitor changes.
- Prostate specific antigen (PSA) is a valuable marker for prostate cancer although BPH or infection may also cause a rise in PSA.
- Normal range is 0-4, however, a PSA above 3 in men younger than 60 may be considered abnormal.
- African-American men and men with a family history of prostate cancer should be examined beginning at an earlier age.
Prostate cancer is most often diagnosed through a blood test measuring the amount of prostate specific antigens (PSA) in the body. However, signs and symptoms of prostate cancer can include:
- Changes in urinary flow: Frequency, urgency, hesitancy.
- Frequent nighttime urination.
- Painful urination.
- Blood in urine.
Other conditions that may cause these symptoms include an enlarged prostate (benign prostatic hypertrophy or BPH) or infection.
After a diagnosis of prostate cancer has been established with a biopsy, the patient should discuss the treatment options with a radiation oncologist and a urologist. Radiation therapy treatment options to cure prostate cancer include:
- External beam radiotherapy.
External beam radiation therapy involves a series of daily outpatient treatments to accurately deliver radiation to the prostate.
There are two principal methods for delivering external beam radiation.
- 3-dimensional conformal radiotherapy (3D-CRT) combines multiple radiation treatment fields to deliver precise doses of radiation to the prostate. Tailoring each of the radiation beams to accurately focus on the patient's tumor allows coverage of the prostate cancer while at the same time keeping radiation away from nearby organs such as the bladder or rectum.
- Intensity modulated radiation therapy (IMRT) is the most recent advance in the delivery of radiation. IMRT improves on 3D-CRT by modifying the intensity of the radiation within each of the radiation beams. This technique allows more precise adjustment of radiation doses to the tissues within the target area, potentially allowing an increased radiation dose to the prostate and reduced doses to nearby normal tissues. Higher doses to the prostate translate into a greater chance for cure, while lower doses to surrounding organs mean fewer side effects.
Both types of external beam radiotherapy are acceptable treatment; IMRT offers advantages for some but not all prostate cancer patients. With either type of therapy, painless radiation treatments are delivered in a series of daily sessions, each under half-hour in duration, Monday through Friday, for seven to ten weeks overall.
Potential side effects, including fatigue, increased frequency or discomfort of urination, and loose stools, typically resolve within a few weeks after completing treatments. Impotence is also a potential side effect of any treatment for prostate cancer. However, many patients who receive radiation therapy for prostate cancer are able to maintain sexual function.
In a few parts of the country, proton beam therapy is being used to treat prostate cancer.
Proton therapy is administered much the same way as external beam therapy, but it uses protons rather than x-rays to irradiate cancer cells.
Certain patients may benefit from hormone therapy in addition to radiation. In some patients, hormone therapy works with radiation therapy to improve cure rates.