Nuclear medicine scans allow doctors to obtain structural and functional information of an organ or a disease.
What is Nuclear Medicine?
These tests are painless and done as an outpatient procedure. The specific type of nuclear medicine scan a patient would undergo depends on the organ which the doctor wants to look into. There are two types of scanners available in the Nuclear Medicine Centre: PET/CT and SPECT/CT. They provide comprehensive information on the abnormal activity and function of cells (obtained by PET or SPECT component) as well as the precise location of these abnormalities in the body (obtained by CT component).
PET/CT (Positron Emission Tomography/Computed Tomography)
PET/CT is a powerful imaging technique that combines both CT scan and PET scan. Using radioactive sugar (FDG – 18F-fluorodeoxyglucose) as the tracer, a PET/CT scan is helpful in:-
- Detecting early diseases such as cancer or infection/inflammation
- Accurately evaluating the spread of disease (staging)
- Evaluating early disease recurrence
- Guiding treatment planning/biopsy
- Monitoring treatment response
SPECT/CT (Single Photon Emission Computed Tomography/Computed Tomography)
SPECT/CT combines two imaging technologies – SPECT which shows biological functions in the body and Computed Tomography (CT) which shows detailed anatomical structures. If a scanner does not have the CT component, it is more commonly known as a Gamma Camera rather than a SPECT scanner. A SPECT/CT scan allows your doctor to see how your organs function and detect certain diseases. It is useful for a range of medical conditions such as bone metastases, renal function, cardiac blood flow, gastrointestinal function, immune activity, thyroid function, tumours and more.
Nuclear Medicine Scans for Cancer
|Name of scan||Purpose|
|FDG 18 Whole Body Scan||Imaging of various cancers (except neuroendocrine tumour and prostate cancer)|
|Gallium 68 DOTATATE Scan||Imaging of neuroendocrine tumour and medullary thyroid carcinoma|
|Gallium 68 PSMA Scan||Imaging of Prostate Cancer|
|Bone Scan||Imaging of bone metabolism; enables identification of the spread of tumour to bone|
|Sentinel node scintigraphy||Identify the pathway of lymphatic spread, most commonly performed in breast cancer and melanoma|
|Radioactive Iodine Whole Body Scan||Detect residual/ recurrent of thyroid cancer|
Most nuclear scans are safe tests. The radiation doses are very small, and the radionuclides have a low risk of being toxic or causing an allergic reaction. Some people may have pain or swelling at the site where the material is injected into a vein. Rarely, some people will develop a fever or allergic reaction when given a monoclonal antibody.
The radiation exposure from a nuclear medicine scan comes from the radionuclides used and from the CT scan. The radioactive material in your body will naturally decay and lose its radioactivity over time. It also leaves your body through urine or stool within a few hours or a few days. Talk to your healthcare team whether you need to take precautions during sex, or being close to children or pregnant women after these tests.
You will be asked to drink a lot of water to flush out the radioactive material.
To reduce the risk of being exposed to radioactive material in your urine after a scan, you should put the lid down and flush the toilet two times, right after you use it.
Nuclear medicine scans are not recommended for pregnant women, so let your doctor know if you are or might be pregnant.
If you are breastfeeding, be sure to tell the doctor ahead of time. You may need to pump your breast milk and discard it until the radionuclide is gone from your system.