BY MARK SCHOLZ, MD One cannot really talk intelligently about prostate cancer without a working knowledge of the PSA blood test. Most people are familiar with using PSA to diagnose prostate …
Tag: Bone Scans
A standard bone scan is performed by injecting radioactive technetium, a calcium analogue that accumulates in areas where the bone is “irritated.” A sophisticated Geiger counter is passed over the body creating an image of the bones. Areas of accumulated radioactivity show up as “hot spots.” These areas of abnormal accumulation are not always the result of cancer. Trauma or arthritis can also cause hot spots. Therefore, bone scan reports have to be interpreted by a clinician familiar with the individual patient.
Bone scan technology has recently experience a serious upgrade. Fluoride 18 PET scans of the bone are decidedly more accurate than the older technetium technology. When F18 PET is available it should always be preferred over a technetium scan.
MRI of the bones with gadolinium contrast is also more accurate than a technetium bone scan. However, general use of MRI for scanning the bones is impractical. First, MRI of the ribs is impossible due to respiratory motion. Second, MRI scanning of large areas of the body is very time consuming. MRI of the bones, therefore, is usually reserved for confirming suspicious but unconfirmed abnormalities detected with a bone scan. MRI of the spine and pelvis is sometime used as a screening tool to obtain the greatest assurance about the absence of bone metastasis.
Metastatic disease is monitored with scans. Radioactive technetium bone scans have been the standard bone scanning method for years. More recently, Fluoride PET bone scans have demonstrated better accuracy. MRI is another accurate scanning technique for evaluating bone. Since many prostate cancer metastases occur in the pelvis or spine, MRI of these areas may pick up metastatic disease when all the other methods are read as clear.