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PET Functional Imaging

Positron emission tomography (PET) is a technique that produces a three-dimensional image of functional processes in the body.
General PET scan information

The PET Functional Cancer Imaging Centre is being developed to:

  • Improve cancer diagnosis and treatment planning for patients and health care professionals
  • Build research programs for the discovery, development and application of new radiotracers
  • Apply new advances in imaging to improve prevention, early diagnosis and management of cancers
  • Collaborate in a growing national and international network of functional imaging programs

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PET & CT

Positron emission tomography (PET) imaging is a procedure that, when combined with computed tomography (CT), help physicians to more accurately diagnose and manage disease, especially cancer.

PET detects changes in cellular metabolism (how active a cell is), often indicating the presence of disease. CT detects changes in the physical size or shape of a lesion and shows exactly where in the body the lesion is located. By combining these two imaging technologies into a single scanner, we are now able to more accurately detect cancer and pinpoint its location in the body.

Together, PET and CT can be very helpful, for example, in the preoperative staging of some cancer types and in localizing suspected cancer recurrence when standard tests are inconclusive. This type of information can help physicians improve treatment planning for individual patients.

petb2.gif    CTWBScan2.jpg       PETCTWBscan2.jpg

Normal PET Scan      Normal CT Scan      Fused PET/CT Scan


How PET/CT Works 

Active cells such as malignant cancer cells will use sugar as an energy source. Inactive cells such as benign cells and scar tissue (both noncancerous) will not use sugar as an energy source. 

In PET, a special type of sugar is combined with a safe radioactive component to produce the radioactive tracer called FDG (Fluorodeoxyglucose). Once injected into a vein, the tracer, which emits signals detected by the scanner, will be absorbed by malignant cells but will not be absorbed by benign cells and scar tissue. This will indicate whether or not a lesion could be cancerous.

Combined with the localizing abilities of CT, this information can be used, for example, to show a surgeon the exact location of a malignant lesion that needs to be removed.

Your appointment 

Upon arrival to the Functional Imaging Department, you will be asked to complete a brief questionnaire. A technologist will take you to an examination room to explain the procedure and answer any questions you may have.  You will then receive the tracer injection and be asked to relax in the private exam room for approximately 60 minutes to allow the tracer to circulate throughout your body. When this "uptake" period is complete, we will take you to the scan room to begin imaging.

Scanning procedure

You will lie on the imaging table which will slowly move you through the scanner while collecting data. For most procedures, you will be able to listen to music during the scan. The scan itself will last approximately 15-45 minutes depending on the type of scan ordered by your physician. 

Once the scan has been completed and reviewed for technical quality, the appointment concludes and you will be free to leave. The entire procedure, from the time you arrive at the BC Cancer Agency until the time you leave, will last approximately 2.5 hours. A report will be sent to your physician once the scan has been read by a radiologist at the BC Cancer Agency.

Risks

A PET/CT scan is considered a diagnostic procedure similar to those done in Radiology and Nuclear Medicine. With over 2 million PET scans having been performed worldwide to date, there have been no reports of any adverse reaction to the tracer. Although there is a small amount of radiation exposure involved in your PET/CT scan, the exposure level is small and within the acceptable limits mandated by Health Canada for these types of procedures. 

Also, tracers used in PET/CT have very short half-lives meaning they don't remain in your body very long. 24 hours after your PET/CT scan, we would not be able to take any more images because the tracer will have completely left your body. 

Patient pre-scan instructions

To prepare for your PET/CT scan, please follow these instructions:

  • Do not eat or drink (except plain water) for at least 6 hours prior to your appointment
  • To keep hydrated, drink 3-4 glasses of plain water within 2 hours of arriving for your appointment (no coffee, tea, juice, pop, etc.)
  • If there is any chance you may be pregnant or breastfeeding, please contact us for further instructions
  • Avoid any strenuous physical activity for 24 hours prior to your appointment
  • Do not chew gum the day of your appointment
  • Take your regular medication(s) as normal if you can take them without food
  • If you are travelling over the border after your PET/CT scan please let us know prior to your appointment so we can prepare a travel letter for you, as trace amounts of radiation will be detectable from you up to 24 hours after your scan
  • Please limit your contact with small children or pregnant individuals for at least 6 hours after your scan 
  • If you are diabetic, see below for special instructions
  • If there is any chance that you will not be able to make your appointment, please call us as soon as possible at 604.707.5951 (toll free 1.800.663.3333, ext. 5951)

For diabetic patients only (in addition to the above instructions):

  • Your blood sugar level must be below 11.1 mmol/L at the time of your appointment (optimally below 8.3 mmol/l)
  • Consult with your physician to determine the safest way possible to manage your blood sugar level before your scan
  • On each of the 3 days prior to your appointment, check you blood sugar level in the morning before eating to see if you are below 11.1 mmol/L in a fasting state. Please call us if your blood sugar is above 11.1 mmol/L on any of the three days prior to your scan.
  • For patients taking insulin:
    • Please call us for further instructions
  • For patients taking diabetic pills (oral hypoglycemic):
    • If you normally have a very low blood sugar level after fasting, skip your diabetic pill the morning of the scan. Otherwise you should be able to take your pills without a problem

If you have any questions, please call us at 604.707.5951 (toll free 1.800.663.3333, ext. 5951)

Frequently asked questions

The following are some frequently asked questions about Positron Emission Tomography (PET).

1. Will my PET/CT scan hurt?

No. The entire procedure is virtually painless except for a small IV needle placed into a vein in your arm to check your blood sugar level and to inject the tracer.

2. How will I feel after the scan is complete?

There are no known side effects from the tracer or scan itself.

3. Who reads the scan?

A qualified Nuclear Medicine physician with PET experience.

4. Will I get my results from the scan before I leave?

No. Due to the large amount of data collected during your scan, data processing takes time and must be completed before our physicians can view the images. Once the images are processed and evaluated, the results will be sent to your family physician.

5. Can I take my medications before coming in for my PET/CT scan?

Most medications won't affect scan results and are okay to take. However, medications with sugar (i.e. cough/cold syrups/throat lozenges) can affect the scan results because of their high sugar content. If you have any questions about the medications you are taking, please contact our reception desk at: 604.707.5951.

6. Can I have a PET/CT scan if I am diabetic?

Yes, but we will need to go over some pre-scan instructions before you arrive. Please refer to the patient preparation page for further instructions or call our reception desk at: 604.707.5951.

7. Can I have someone sit with me during the scan?

Due to the small amount of radiation exposure you receive during the scan, we do not encourage other people to sit with you during the procedure. A general guideline is that only when medically necessary should you receive radiation exposure no matter how small that exposure may be.

8. Why does the whole procedure take 2-3 hours in total?

Upon arrival, a technologist and/or a doctor will explain the procedure in detail and answer any question you may have. An IV will then be placed in a vein for injection of the tracer followed by a 60 minute "uptake period" allowing the tracer to distribute throughout your body. We will then perform your PET/CT scan which will last for about 15-45 minutes depending on the scanning protocol required. All in all, you end up spending about 2-3 hours with us.

9. Is the radiation harmful?

The PET/CT scan is considered a very safe procedure. The amount of radiation exposure from the entire procedure is considered safe and medically necessary by your physician. Also, the tracer leaves your body very quickly. Within 24 hours after scan conclusion, the tracer will be virtually undetectable by our sensitive scanners.

10. Can I eat before coming in for my scan?

No. It is very important that you don't eat or drink anything (except plain water) for at least 6 hours before your PET/CT scan. Sugars that your body absorbs from food can greatly alter the scan quality and results. Fasting ensures that your blood sugar level is not too high prior to starting the procedure. Water is recommended prior to your arrival for the scan. Please refer to the patient preparation page for further information and instruction.

11. How do I get to my appointment?

The Functional Imaging Departement (PET) is located on the 1st floor at the BC Cancer Agency's Vancouver Centre. The building address is:

600 West 10th Avenue

Vancouver, B.C. V5Z 4E6

PET Reception: 604.707.5951

12. Can I still have a PET/CT scan if I'm allergic to IV contrast used in Computed Tomography (CT)?

Yes. The CT portion of the scan is commonly done without contrast. The tracer that is injected for the PET portion is not a contrast type agent and will not cause an allergic reaction.

13. What should/can I wear to my appointment?

Loose comfortable clothing without metal is recommended. Any metal items in clothing or worn as jewellery (i.e. metal buttons, zippers, piercings, hairpins, etc) will affect the scan quality and will need to be removed for the scan. If necessary, you will be asked to change into a patient gown to ensure scan quality.

14. What is a radiotracer/radiopharmaceutical?

A radiotracer/radiopharmaceutical is a radioactive compound that can trace a certain body function without any side effects. Depending on how they are made, there are many different radiotracers that can show entirely different body functions. In PET, we most commonly use a radioactive form of sugar which can show different areas of metabolic activity in the body indicating the presence or absence of disease.

15. Do I have to pay for my scan?

If you are covered by the provincial health plan and your indication meets the BC Cancer Agency's specific approved indications for PET/CT scanning, you will not be charged a fee for your procedure if done at our facility.

16. How do I get referred for a PET/CT scan?

If your physician feels that a PET/CT scan is medically necessary and meets the BC Cancer Agency's criteria for currently approved indications, he/she will contact our centre to book an appointment. Once we have been able to book the appointment, we will then contact you to confirm the date and time as well as go over any instructions you will need to follow prior to arriving.

17. Do I have to be a cancer patient at BC Cancer Agency to get a PET/CT scan?

No. If you have never been to the BC Cancer Agency but have been approved to have a PET/CT scan done at our facility, we will first generate an Agency patient identification number and then book your procedure as soon as possible.

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