PSA levels tend to decrease after radiation treatment, reports the American Cancer Society. However, the drop in a PSA level is gradual and can take up to 2 years or more for the level to reach its lowest point. PSA refers to the prostate-specific antigen, which is a protein produced by the prostate gland.
A blood test can check PSA levels. When these levels are high, it can be an indication of an inflammation, infection, enlargement or cancer of the prostate gland, reports WebMD. However, to determine the cause for an elevated level in PSA, another test may be performed by a doctor, such as a biopsy. When the diagnosis is prostate cancer then a series of tests may be done to evaluate if the cancer has spread beyond the prostate. These tests can include bone scans, MRIs and CT scans. These exams are useful for staging prostate cancer in a patient, relates the National Cancer Institute. There are four stages in prostate cancer.
Treatment options can depend on the cancer stage, and these options can include surgery, chemotherapy, radiation, hormone or biologic therapy. Although radiation therapy can lower PSA levels, surgery will also lower these levels, states the American Cancer Society. Prostate surgery can be complete removal of the prostate gland. After surgery, it can take a couple of months for PSA levels to decrease.