PET Scan for Prostate Cancer

Pet Scans Can Help Your Doctor Determine If Your Cancer Has Spread

Man Receiving Medical Scan for Prostate Cancer Diagnosis
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If you have prostate cancer, your doctor might order a PET scan. A PET scan can help determine if your prostate cancer has spread to other areas in the body and, if so, where.

What is Prostate Cancer?

Prostate cancer develops in the prostate—a small gland that makes seminal fluid. It is one of the most common types of cancer in men. Prostate cancer usually grows over time, staying within the prostate gland, where it may not cause serious harm, in the beginning.

While some types of prostate cancer grow slowly and may need minimal or no treatment, other types are aggressive and can spread quickly.

Advanced prostate cancer can cause signs and symptoms such as:

  • Difficulty urinating
  • Decreased force in the stream of urine
  • Blood in the semen
  • Discomfort in the pelvic area
  • Bone pain
  • Erectile dysfunction

What Is a PET Scan?

The acronym "PET" stands for positron emission tomography. During a PET scan, tiny amounts of radioactivity, which are injected into your body, are detected outside of your body by a large machine commonly known as the PET scanner.

A PET scan involves the injection of a form of radioactively tagged glucose, a sugar that the body naturally metabolizes or uses. Tissues in your body that use up a lot of glucose will also use up a lot of the special radioactively tagged glucose used for the PET. Those tissues will then be marked with radioactivity that can be detected by the PET scanner.

Lots of normal tissues rapidly use glucose such as the heart, liver, spleen, and kidneys. What makes the PET scan useful, however, is that cancer cells typically also use a lot of glucose because they are dividing and multiplying at a much higher rate than normal cells.

By detecting abnormal sites of high glucose use on the PET, doctors can determine where there may be additional areas of cancer scattered throughout the body.

This can help doctors choose the most appropriate treatment.

At many hospitals, PET scans are now combined with CT scans to help your doctor more easily determine where your cancer has spread.

PET Scan Alternatives and Additives

The most used, and useful, test for detecting prostate cancer metastases is the bone scan. Bone scans are a type of imaging test that can tell if your cancer has spread or metastasized to your bones. During a bone scan, you will be injected with radioactive material, which helps the bone scanner detect any irregularities in your bones including cancer and fractures. 

For some reason, prostate cancer cells do not seem to rapidly use the radioactively labeled glucose injected for a PET exam. This means that, even if there is prostate cancer that has spread to another area of the body, the PET scan could very well miss it.

To make your PET scan more accurate, your doctor might recommend an Axumin PET scan. Axumin is an injection used during PET scans and can help your doctor identify areas of cancer recurrence. 

References:

Brant and Helms. Fundamentals of Diagnostic Radiology. 2006.

Mayo Clinic. Prostate Cancer. 

Axumin Injection Website. 2017.

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