A ProstaScint® scan may be used in the diagnosis of prostate cancer to evaluate the extent of the disease and to detect the spread of cancer to other areas of the body, particularly the lymph nodes. A small amount of radioactive material combined with a monoclonal antibody is injected into and circulates throughout the body, attaching itself to an antigen located on prostate cancer cells. This material acts as a tracer, indicating through images taken with a gamma camera where cancerous cells may reside. Doctors may recommend this screening test either in the initial evaluation or post-treatment follow-up of patients with prostate cancer.
Patients who undergo a ProstaScint scan can expect the procedure to span over a few days:
- Day one, an intravenous tracer injection of radioactively tagged antibodies will be administered. After approximately 30 minutes or once the tracer is carried in the blood and distributed throughout the body, patients will have images taken of their abdomen by a gamma camera to detect the tracer absorbed by the body.
- Day three, patients will be asked to take a laxative and/or use an enema to cleanse their bowel so that there are no image obstructions.
- Day four, patients will be situated next to a gamma camera for about 45 minutes. A small sample of blood will be taken, mixed with more radioactively tagged antibodies, and then re-injected into the patient’s body. The patient will then be moved to a different camera for a final hour of imaging.
A ProstaScint scan may be used in conjunction with computed tomography (CT) or magnetic resonance imaging (MRI) scans to help pinpoint “hot spots” (or areas with a large number of prostate cancer cells). By analyzing the data obtained from the images, doctors are able to determine an optimal prostate cancer treatment plan. Careful analysis of the images and medical reports must be done, however, because the antibody material detects only dead cells. Healthcare providers who have been expertly trained on the ProstaScint scan will reduce the risk of false negatives or false positives. Patients who undergo a ProstaScint scan receive about as much radiation as similar x-ray procedures.