In cases where a patient has been diagnosed with prostate cancer, a doctor will combine the results of their digital rectal exam (DRE), prostate-specific antigen (PSA) and Gleason score from their biopsy to determine whether their cancer has a chance of spreading (metastasizing) beyond the prostate gland. The compiled data is then used to determine if an imaging test is required to search for any potential spread of the prostate cancer. Generally patients who have low PSA level, a normal DRE result and low Gleason score will not need any further testing. This is because the likelihood of the cancer metastasizing into other areas of the body is very low. Imaging technology is increasingly being used to help health professionals in both diagnosing and treating prostate cancer, so let’s take a look at some of the imaging tests commonly used to detect the spread of prostate cancer.
Computed Tomography (CT) Scan
The CT scan utilizes x-rays to create intricate cross-sectional images of the body. As opposed to an x-ray where one image is taken, a CT scanner will take multiple images as it rotates around your body while you remain still on a table. The computer will then combine the images to create a picture of the particular area of the body that will be studied. In some instances you may be required to drink an oral contrast, which helps to outline and differentiate the intestines from any tumors. A CT scan is also helpful in detecting if the cancer has spread into the lymph nodes.
The bones are one of the most common areas prostate cancer will spread into. A bone scan is useful in determining whether the cancer has spread (metastasized) into the bones. A small low-level dose of radioactive material (radiopharmaceuticals) is injected into the vein intravenously. This radioactive material will then collect into the damaged areas of bone referred to as “hot spots”. Generally after about 30 minutes you will then lie flat on a table where a specialized camera will take photos to generate an image of the skeleton using the radioactive material that have collected in the damaged areas.
Magnetic Resonance Imaging (MRI)
An MRI scan is useful in looking at prostate cancer by incorporating the use radio waves and strong magnets to create a clear 3D image of the prostate. This will helps to determine whether the cancer has spread into other areas of the body. An MRI scan can last up to an hour and you will lie in a narrow tube as the scan is taken. Since the scanner uses magnets patients with medical implants such as a pacemaker are unable to get an MRI. In some cases a probe called an endorectal coil is placed in the rectum and used to ensure the accuracy of the scan. A sedative may be given to the patient to alleviate any pain or discomfort from the probe.