What
is PET-CT?
Positron Emission Tomography or PET is a special Nuclear Medicine
test used to measure changes in the body that are associated with
many diseases. PET-CT provides information about metabolic or body
process changes which may occur before changes in anatomy. The metabolic
information from the PET and the anatomic data from the CT combine to help best locate any lesions
in the body. The CT scan works to bring together the data. It does
not function as a full diagnostic CT scan. The CT scan is usually
performed first and then followed-up, with a separate PET-CT exam.
What is FDG?
FDG, or F-18 fluorodeoxyglucose, is a radioactive tracer. This
tracer is a form of
glucose, or sugar which is injected before the PET-CT scan. The
PET-CT scanner will show how the body is utilizing the radioactive
glucose. If there is a specific disease, the glucose may highlight
or take up more glucose in the diseased area
than in other parts of the body. Physicians can then determine
how to best treat those areas.
When is PET-CT used? — Clinical
Applications
PET-CT is very accurate in showing the presence or spread of many
malignant tumors. For example, it is more accurate in detecting
the spread of non-small cell lung cancer and recurrent colon cancer
than any other imaging method currently available. A high degree
of accuracy has also been determined in evaluating lymphoma, melanoma,
recurrent breast cancer, esophageal cancer, ovarian cancer, recurrent
brain cancer, and tumors of the head and neck. Specific applications
of PET-CT are:
• Tumor Detection - Initial Diagnosis and Recurrent Disease
• Differentiating Malignant from Benign Tissue
• Evaluating the Entire Body to Determine the Extent of Disease
• Evaluating if a Tumor is Responding to Treatment
• PET-CT has shown
a high degree of accuracy for determining the presence
or spread of many malignant tumors.
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– Lung Cancer |
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– Colorectal Cancer |
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– Ovarian Cancer |
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– Melanoma |
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– Breast Cancer |
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– Brain Cancer |
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– Lymphomas |
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– Pancreatic Cancer |
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– Head & Neck Cancer |
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– Esophageal Cancer |
• Brain tumor grading: recurrent tumor vs. radiation necrosis.
• Epilepsy: detection of foci, support of surgery.
• Dementia: differentiation
of dementia, Alzheimer’s, Huntington’s chorea.
Are there risks associated
with PET-CT?
A PET-CT scan is similar to other diagnostic tests such as CT or
MRI. The potency of the radiotracer is similar to what patients
receive for CT. The radiopharmaceutical used for PET-CT does not
remain in the patient’s body very long, so there is no reason
to avoid other people once the scan is completed.
Clinical Case Studies
Please click on the case study you would like to see (PDF)
PET: Diagnosis and Staging of The Indeterminate Pulmonary Nodule
Lung Cancer Staging: PET Shows Extensive Stage IV Disease
PET: Diagnosing and Staging/Restaging of Lymphoma
Patient Preparation
• For a period of
6 hours prior to the PET-CT appointment, the patient may have
nothing to eat or drink except plain water. This will insure that that the scan is
as accurate as possible.
• Regularly scheduled medications may be taken as needed, if they can be
tolerated on an empty stomach.
• Patients who have diabetes or have claustrophobia, should let us know before
coming in for the appointment. Our staff will provide special instructions
for the scan.
• Warm and comfortable clothing should be worn for the scan. Jewelry or
anything made out of metal should not be worn because these items may
interfere with the scan.
• The patient should plan to spend 2 to 3 hours at our office.
• Patients
should not exercise on the day prior to the PET-CT scan or
on
the day of the PET-CT scan.
What to bring to the
PET-CT scan appointment
• The written referral from the referring physician.
• Any previous CT,
MRI, and PET-CT films and reports. The referring
physician may arrange to have these sent
to University Radiology
directly or have the patient bring
them with them on the day of the scan.
• The patient’s
favorite music on CD to listen to during the PET scan.
Why coming to the appointment on time is very important
The PET-CT scan appointment time is carefully chosen to insure
that the radiotracers are as fresh as they need to be to obtain
an accurate study. If the patient cannot arrive on time or needs
to reschedule the appointment, please call us right away at 800-758-5545,
and we will give further instructions.
What to expect during and after the scan
• When the patient arrives at our center, they will be asked to complete
a history questionnaire.
• We will then check the patient’s glucose (sugar) level. If this level is normal,
the patient will then receive a small amount of radioactive glucose in the arm.
There will be no side-effects from the injected radiotracer. The patient will
feel fine.
• The patient will
then wait 30 to 60 minutes while the injected material
circulates through the body.
• The patient will then be asked to lie on a table without moving while the scan
is taking place. The scan usually takes 30 to 60 minutes to complete. Our
technologists will be talking with the patient during the study.
• When the scan is completed, the patient will be free to go home. We
encourage the eating and drinking of
extra fluids after the scan. The
patient may eat or drink whatever they
wish.
Study results
The results of the PET-CT scan at University Radiology will be
called or faxed to the referring physician usually within 24
hours. A copy of the PET-CT report, as well as printed images,
will be sent to the physician. The referring physician will then
review the scan findings with the patient.
Scheduling, Referrals & Insurance Coverage
To schedule an appointment, please call University Radiology at 800-758-5545.
We will work to get an appointment time convenient for the patient.
Patients will need to be precertified with their insurance carrier prior to their scan. Our office staff will help with that process.
Coverage by carriers will vary and is changing rapidly as the
clinical value and cost-effectiveness of PET-CT is becoming more
well known. If you have questions about insurance coverage and
billing, please call us at 800-758-5545, and we will be happy to
help you.
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