Positive Bone Scan Vs. PSA

With the exception of skin cancer, prostate cancer is the most common form of cancer in America, according to the Prostate Cancer Foundation. Several tests are involved in detecting and managing prostate cancer.

PSA

• PSA involves drawing blood from the arm, according the American Association of Clinical Chemistry. This test looks for prostate specific antigens, which are located in prostate cells, according to the U.S. National Library of Medicine.

Bone Scans

• Bone scans, on the other hand, detect whether a patient's existing cancer has spread to the bones. When someone undergoes a bone scan, a radioactive material (radiotracer) is injected to the bloodstream and allowed to settle in the bones, according to the U.S. National Library of Medicine. A bone scan is subsequently conducted to detect the radiotracers.

Positive Bone Scan Results

• If the radiotracers show an even distribution throughout the body, the body scan is considered normal. Positive bone scans show either areas with a high amount of radiotracers (hot spots) or low amount of radiotracers (cold spots).

PSA Results

• PSA levels above 10 nanograms per milliliter indicate a high chance (over 50 percent) of prostate cancer, according to the American Cancer Society. PSA levels between 4 and 10 nanograms per milliliter indicate a raised risk (25 percent) of prostate cancer.