Other Exams to Determine If Prostate Cancer Has Spread
A CT scan combines x-rays and computer imaging to produce images of organs in your body. The CT scan may help detect lymph nodes in the pelvis that are enlarged because of cancer. Generally, a CT scan is used only if the cancer is intermediate or high risk.
Magnetic resonance imaging is similar to a CT scan except that it uses magnetic fields instead of x-rays to create internal pictures of your body. MRI is very good at imaging the prostate but has limited usefulness for distinguishing benign from cancerous areas. Standard MRI, therefore, has limited usefulness for determining the extent of disease.
There is a new MRI technology that uses a probe, called a coil, inserted in the rectum to create an image of the prostate. This technique, also known as endorectal MRI, has been shown to be more accurate for predicting whether the cancer has moved beyond the capsule of the prostate and for predicting whether it has spread into the seminal vesicles.
A test called a bone scan is performed to see if the cancer cells have spread to the bone. For this test, a radiology technician injects a small amount of radioactive material into your bloodstream and then has you return three hours later for the scan. The radioactive material collects in the area where there are bone-activating cells. A scanner then pinpoints the areas where the radioactive material collects, so these areas can be evaluated for possible sites of bone metastasis. This study is not necessary in patients with low-risk cancers.
The lymph nodes are often the first location where prostate cancer spreads. Usually, the physician can estimate the likelihood that cancer has spread to the lymph nodes based on the rectal examination, PSA and biopsy results. If there is a high likelihood that the cancer has spread to the lymph nodes, the physician may elect to surgically sample, remove and examine the lymph nodes under a microscope. If the lymph nodes are positive for cancer, then metastatis (spread) has likely occurred and surgery to remove the prostate (radical prostatectomy) might not be recommended.
Intravenous pyelogram (IVP)
With this procedure, you will be injected with a special dye and x-rays will be taken of your kidneys, ureters and bladder.
A simple x-ray will be done to determine if cancer has spread to the lungs or ribs.