If cancer recurs after radiation
Following treatment with radiation for prostate cancer, a man's PSA should decline to a very low level (a PSA nadir) and remain there. Elevations about the nadir can be concerning and a PSA that is 2ng/ml above the nadir can be particularly concerning for clinically relevant recurrences. When PSA elevates after radiation therapy, this could indicate that there is untreated disease in the prostate or spread around the body. Typically an evaluation will be carried out to look for metastatic disease and if none is found, the prostate can then be evaluated (by biopsy and sometimes by imaging) to determine if viable cancer cells are present. If cancer is found and is only in the prostate then more local therapy can be employed. This is typically performed by "salvage" cryotherapy or prostatectomy. Salvage cryotherapy is an FDA approved, minimally invasive procedure in which the prostate is frozen in order to kill cancer.