PET/CT (Positron Emission Tomography/Computed Tomography) PET scans is a less evasive alternative for Cancer patients and is taken before and after a chemotherapy cycle to compare the tumour metabolism levels.

A successful response seen on a PET scan is often noticed before any changes in anatomy therefore making it an earlier indicator of tumour response compared to other diagnostic modalities. It is especially effective in identifying whether or not a cancer is present; in particular lung, head and neck, colorectal, oesophageal, lymphoma, melanoma, breast, thyroid, cervical, pancreatic and brain cancers as well as other less frequently occurring cancers. It can also be used to assess your response to treatment.

PET images indicate biochemical activity that enables the scan to accurately characterise a tumour as benign or malignant thereby avoiding surgical biopsy when the scan is negative. Conversely, because a PET scan images the entire body, the confirmation of distant metastases (malignant growths) can alter treatment plans in certain cases from surgical intervention to chemotherapy.

Staging of cancer

PET is extremely sensitive in determining the full extent of disease especially in lymphoma, malignant melanoma, breast, lung, colon and cervical cancers. Confirmation of metastatic disease allows the Physician and patient to decide more accurately on how to proceed with the patient’s management diagnosis.

Checking for recurrences

PET is currently considered to be the most accurate diagnostic procedure to differentiate tumour recurrences from radiation necrosis or post-surgical changes. This approach allows for a more rational treatment plan for the patient.

PET is a form of Nuclear Medicine Imaging (also known as a Radio Isotope). This uses small amounts of radio-active pharmaceuticals to image the body and help diagnose or treat a variety of diseases. The procedure determines the cause of the medical problem based on the function of the organ, tissue or bone.

Without Nuclear Medicine Imaging this information may not be available, the alternative being surgery or more expensive and invasive diagnostic tests. X-Rays and CT scans show how your body looks whereas Nuclear Medicine shows how your body works.

The radio-pharmaceutical is injected, swallowed or inhaled (in the form of a gas). This energy is then detected by a gamma camera.

Preparing for your PET/CT Scan

  • Provide a brief summary of your medical history, your current medications and treatments (e.g. Chemotherapy, Radiation Therapy and Surgery).
  • DO NOT EAT for at least 6 hours before the exam.
  • Drink 3 to 4 glasses of plain water and take your usual medications if they can be tolerated on an empty stomach.
  • Wear loose fitting, comfortable and warm clothing to the test.
  • Leave all watches, jewellery and metallic objects at home.
  • Notify the radiographer if you are pregnant, breast feeding or have an iodine allergy.
  • Do not exercise 24 hours before your exam.
  • Bring ALL previous X-rays and CT scans with you.
  • If your scan requires oral contrast, additional information will be given to you by the Radiographer.


  • Speak to the PET/CT Radiographer or Doctor for specific instructions with regard to insulin.
  • Your blood sugar levels should be between 100-200 mg/dL (5.5 to 11.1mmol/l); however, if your blood sugar levels are high or low the scan may still proceed.

Before your PET/CT Scan

  • You need to be in the department at least 2 hours before your scheduled time.
  • The PET/CT staff will place a small intravenous line for the injection of the Radio Isotope called FDG.
  • Your blood sugar level will be tested.
  • Following the FDG Injection you will be asked to sit quietly for 60 minutes to allow the Isotope to be distributed throughout the body.

During your PET/CT Scan

  • You will be asked to empty your bladder before the scan.
  • It is vital that you lie still during the scan.
  • Scanning on the PET/CT scanner takes approximately 30 to 40 minutes.

After my PET/CT Scan

  • Once the scan is complete you may leave the PET/CT Centre.
  • Drink plenty of fluids to flush the Isotope out of your body.
  • You may resume your normal diet.
  • No side effects will be felt from the radioactive injection.
  • After your scan has been completed, the radioactivity will be within normal and safe limits.

Waiting for your results

The PET/CT scan is interpreted by a trained Radiologist and Nuclear Physician and the results will usually be conveyed to your referring doctor within 1 to 2 days. You will need to contact your referring doctor to discuss the results.

Gateway Private Hospital
36-38 Aurora Drive, Umhlanga Rocks
Tel: 087 310 4985

Send us a Message

You can contact us by using our contact form below. We look forward to hearing from you.