Typically, the prostate-specific antigen, or PSA levels after radiation therapy drop to very low or even undetectable amounts, states the American Cancer Society. A post-operative check-up of PSA levels is usually recommended within 6 to 8 weeks after surgery.
Ideally, the PSA level of a cancer patient following radical prostatectomy is zero nanograms per milliliter, since the operation involves the removal of the entire prostate gland, notes Harvard Medical School. However, minute traces of PSA may still remain in the blood, which indicates a serious health concern if the PSA level continuously increases.
A blood PSA level of 2 to 3 ng/mL generally means not all malignant cells were eliminated by the treatment. It can also signify a recurrence of the prostrate cancer.