What are some common uses of the procedure?

PET and PET/CT scans are performed to:

• Detect cancer.
• Determine whether a cancer has spread in the body.
• Assess the effectiveness of a treatment plan, such as cancer therapy.
• Determine if a cancer has returned after treatment.
• Determine blood flow to the heart muscle.
• Determine the effects of a heart attack, or myocardial infarction, on areas of the heart.
• Identify areas of the heart muscle that would benefit from a procedure such as angioplasty or coronary artery bypass surgery (in combination with a myocardial perfusion scan).
• Evaluate brain abnormalities, such as tumors, memory disorders and seizures and other central nervous system disorders.
• To map normal human brain and heart function.

What are the benefits vs. risks?

Benefits

• The information provided by nuclear medicine examinations is unique and often unattainable using other imaging procedures.
• For many diseases, nuclear medicine scans yield the most useful information needed to make a diagnosis or to determine appropriate treatment, if any.
• Nuclear medicine is less expensive and may yield more precise information than exploratory surgery.
• By identifying changes in the body at the cellular level, PET imaging may detect the early onset of disease before it is evident on other imaging tests such as CT or MRI.

The benefits of a combined PET/CT scanner include:

• Greater detail with a higher level of accuracy; because both scans are performed at one time without the patient having to change positions, there is less room for error.
• Greater convenience for the patient who undergoes two exams (CT & PET) at one sitting, rather than at two different times.

Risks

• Because the doses of radiotracer administered are small, diagnostic nuclear medicine procedures result in low radiation exposure, acceptable for diagnostic exams. Thus, the radiation risk is very low compared with the potential benefits.
• Nuclear medicine diagnostic procedures have been used for more than five decades, and there are no known long-term adverse effects from such low-dose exposure.
• Allergic reactions to radiopharmaceuticals may occur but are extremely rare and are usually mild. Nevertheless, you should inform the nuclear medicine personnel of any allergies you may have or other problems that may have occurred during a previous nuclear medicine exam.
• Injection of the radiotracer may cause slight pain and redness which should rapidly resolve.
• Women should always inform their physician or radiology technologist if there is any possibility that they are pregnant or if they are breastfeeding their baby.

What are the limitations of Positron Emission Tomography - Computed Tomography (PET/CT)?

• Nuclear medicine procedures can be time-consuming. It can take hours to days for the radiotracer to accumulate in the part of the body under study and imaging may take up to several hours to perform, though in some cases, newer equipment is available that can substantially shorten the procedure time. You will be informed as to how often and when you will need to return to the nuclear medicine department for further procedures.
• The resolution of structures of the body with nuclear medicine may not be as clear as with other imaging techniques, such as CT or MRI. However, nuclear medicine scans are more sensitive than other techniques for a variety of indications, and the functional information gained from nuclear medicine exams is often unobtainable by any other imaging techniques.
• PET scanning can give false results if chemical balances within the body are not normal. Specifically, test results of diabetic patients or patients who have eaten within a few hours prior to the examination can be adversely affected because of altered blood sugar or blood insulin levels.
• Because the radioactive substance decays quickly and is effective for only a short period of time, it is important for the patient to be on time for the appointment and to receive the radioactive material at the scheduled time. Thus, late arrival for an appointment may require rescheduling the procedure for another day.
• A person who is very obese may not fit into the opening of a conventional PET/CT unit.