DOCTORS’ CORNER

HOW DO I REQUEST A PET SCAN?
    1. Please complete the Cape PET/CT request form, available for download on this link. Alternatively, you may request a booklet / electronic editable copy from our office.
    2. Please complete the form as thoroughly as possible.  We use it to obtain medical aid authorisation and when reporting the scan. 
  • An in depth clinical history is key, please include:
  • Clear indication/reason for referral
  • Current symptoms
  • Date of diagnosis
  • Type of histology and report 
  • Previous treatment history including:
    • Chemotherapy including date of last dose
    • Radiotherapy including area and date completed
    • Whether granulocyte stimulating colony factor was given and the date of the last dose
    • Surgery area and date
  • Previous surgeries unrelated to the condition that may influence our scan interpretation such as recent ORIF for a fracture, joint replacements etc.
  • Previous imaging findings and reports

Although all patients are seen by one of the attending doctors at time of the PET/CT, patients often do not know their complete history.

    1. You can send the request form to info@petct.co.za
  • We will send the form to the medical aid to obtain authorisation. 
  1. If the patient is on the oncology benefit, the medical aid authorisation usually takes 3-5 working days, but this can depend on the medical aid or the indication for the scan. Further documents are often requested by the medical aid or the request is sent to the clinical advisor of the medical aid – this may cause a delay in authorisation.

This emphasises the importance of completing an in depth clinical history including attachments of histology reports, radiology reports and other relevant procedures.

    1. If a patient is NOT on a medical aid, and they would like to pay cash for the investigation, please state this on the request form. A quote can be obtained and our accounts department will liaise with the patient regarding payment terms and conditions (if applicable).  
    2. Preferably do not schedule any other appointments for your patient on the same day as the PET/CT scan. There are often unforeseeable delays and times are just a guideline.
  • When scheduling a follow-up appointment with the patient to review the PET/CT scan results, please do not schedule the appointment on the same day or too early the following day. The report will only be available after 12h00 the workday following the PET/CT scan.
  • The report will be sent via email or faxed to the referring physician. The result of the scan will not be discussed with the patient at the Cape PET/CT centre.
  1. Images will be sent to the PACS system of the referring radiology practice. If this is not possible, the patient will have a copy of the images on a disc. The disc has FUSED AXIAL and CORONAL slices as well as a viewing tool for your convenience.
  2. If DICOM data is needed for CT planning, please request a disc from our department. You may also request an electronic transfer of the images.  All images are stored for future reference.

 

Please do not hesitate to contact us at any time at the Cape PET/CT centre for more info.

 

How long should I wait after treatment before requesting a PET/CT?

Certain guidelines have been set-up to reduce false-positive and false-negative findings on a PET/CT.

It is therefore advisable to wait to following time-period after therapy:

    • Chemotherapy: 
      • For interim PET/CT restaging (lymphoma): 2 weeks
      • For end-of therapy restaging (lymphoma): 4-6 weeks
  • For other malignancies: 2-4 weeks
  • Colony growth stimulating factor/Neupogen: 10 days to 2 weeks from last injection
  • Radiotherapy: 3 months after the last treatment
  • Surgery:  at least 1 month 

We do understand that sometimes it is necessary to perform these scans before this time has passed If this is the case, please discuss this with one of the Cape PET/CT Nuclear Physicians at time of booking. 

 

My patient is scared of radiation: how can I explain this to them?

The radiation dose that we use is fairly small. We strictly adhere to the ALARA principal, which stands for “As low as reasonably achievable”. We thus try to obtain an image that is of sufficient quality for interpretation at lowest possible radiation dose to the patient.

All doses are carefully calculated for each patient according to their weight. In addition, newer technology has allowed us to reduce the injected dose required for imaging when compared to older scanners, thereby also reducing the radiation exposure to the patient.

Please refer to the article on Radiation exposure in everyday which can be found using the following hyperlink:  https://www.iaea.org/Publications/Factsheets/English/radlife for further information.

 

What types of diseases can be imaged with F-18 FDG PET/CT?

Most of the patients undergoing a PET/CT scan is patients that have already been diagnosed with cancer. In oncology this modality can be used for staging, restaging, detecting recurrences, follow-up/surveillance, response assessment and even radiotherapy planning. It can also be used in primaries of unknown origin, when all investigations have been unable to detect the primary, PET/CT has been shown to detect primary tumours in up to 50 % of these patients. 

Although most of our patients are oncology patients, PET/CT is also very useful in imaging infection and inflammatory conditions amongst other indications. Some of these include investigation of fever of unknown origin, to diagnose and monitor treatment of large vessel vasculitis (e.g. Takayasu’s arteritis), assessment of a prosthetic valve infection or suspected vascular graft infection, in assessment and therapy monitoring in cardiac sarcoidosis and even in to detect viable myocardium in patients with ischaemic heart disease.

 

Please follow this link to download the recently published list of indications for a PET/CT.

PREPARING MY PATIENT PET/CT STUDY

PREPARING MY PATIENT FOR F-18 FDG PET/CT STUDY

DO:

  • Wear comfortable, loose fitting clothes, preferably without metal/zips. You may be asked to change into a gown for the investigation.
  • Keep yourself warm, this improves our image quality.
  • Drink lots of plain, unflavoured water (before and after the study).
  • Continue using your normal medication as prescribed by your doctor (if it can be tolerated on an empty stomach) EXCEPT insulin. If you are a diabetic please refer to the section lower down on “Preparing my diabetic patient for F-18 FDG PET/CT study” or contact the PET/CT Practice.
  • It is always a good idea to bring a list of the medication you are taking when going to a doctor’s appointment/investigation.
  • Inform us on arrival if you know you suffer from claustrophobia.
  • Bring medication along that you may need for the investigation e.g. pain-relief/anti-anxiety medication. If you think you may need a sedative/anti-anxiety medication for the investigation, please make sure you have someone that can drive you home after the investigation.
  • Inform the radiographer if you are pregnant (or think you may be), breastfeeding or have any allergies.

DO NOT:

  • Do strenuous exercise 24 hours before the study.
  • Eat or consume calories or anything with sugar 6 hours before the study (this includes sugar free gum, breath mints etc.). *

Diabetic patients should not use their rapid acting for 4 hours before and short-acting insulin 6 hours before the investigation – please refer to the section lower down on “Preparing my diabetic patient for F-18 FDG PET/CT study”.

 

Preparing my diabetic patient for F-18 FDG PET/CT study

Special instructions for diabetic patients:

It is very important that the patient’s blood sugar is well controlled before the study. Following a balanced diet for a few days before the study will assist in ensuring that your blood sugar level is within normal (or near-normal) levels on the day of the study.

If the blood sugar is higher than 12 mmol/l on the day of the study, the study will have to be cancelled.

Type I Diabetes/Insulin-dependent diabetics:

  • The study will usually be booked during late morning.
  • Patients should please have a small breakfast no later than 06h00 and then take their insulin. The injection will be scheduled 6-hours after the insulin injection. Patient’s should not use rapid acting insulin for 4 hours before and short-acting insulin for 6 hours before the study time.
  • After this they may only have plain, unflavoured water.

Type II Diabetes/patients on oral diabetic medication only:

  • The study will usually be booked during late morning.
  • The patient may have a small breakfast and take their diabetic medication at 05h00. The study will be scheduled 6-hours after your meal.
  • After this the patient may only have plain, unflavoured water.

 

Preparing my patient for cardiac inflammation assessment:

  • Purpose: Metabolic preparation prior to PET scan performed to identify inflammatory pathology of the heart, including cardiac sarcoidosis and cardiac infections, is very important. The aim of this diet is to suppress normal glucose usage by the heart muscle and force it to rather use energy from fat.
  • Details: A high-fat, high-protein, very-low carbohydrate diet should be followed for ideally 3 days prior to the study followed by a prolonged period of not eating before the scan, for at least 12 hours.

 PREPARING MY PATIENT FOR GA-68 PSMA/GA-68 DOTA PET/CT STUDY

DO:

  • Ga-68 DOTA: Stop long-acting somatostatin such as Sandostatin/Lantreotide for 4 weeks prior to the PET/CT scan/book the scan just before the next dose or stop short-acting somatostatin such as octreotide for at least 24 hours prior.
  • The patient may have a meal before you come for the study, there is no need to fast.
  • Wear comfortable, loose fitting clothes, preferably without metal/zips. You may be asked to change into a gown for the investigation.
  • Drink lots of fluids (before and after the study).
  • Continue using normal medication as prescribed by your doctor. 
  • It is always a good idea to bring a list of the medication you are taking when going to a doctor’s appointment/investigation.
  • Inform us on arrival if you know you suffer from claustrophobia.
  • Bring medication along that you may need for the investigation e.g. pain-relief/anti-anxiety medication. If you think you may need a sedative/anti-anxiety medication for the investigation, please make sure you have someone that can drive you home after the investigation.
  • Inform the radiographer if you are pregnant (or think you may be), breastfeeding or have any allergies.
PREPARING MY PATIENT FOR F-18 FDOPA PET/CT STUDY

DO:

  • Please fast for at least 4-hours prior to this study, preferably not eating or drinking anything other than plain unflavoured water from midnight the previous evening. 
  • Diabetic patients, please ensure that their blood sugar level is not too low, too high is not a contra-indication to this study.
  • Wear comfortable, loose fitting clothes, preferably without metal/zips. You may be asked to change into a gown for the investigation.
  • Continue using your normal medication as prescribed by your doctor (if it can be tolerated on an empty stomach).
  • It is always a good idea to bring a list of the medication you are taking when going to a doctor’s appointment/investigation.
  • Inform us on arrival if you know you suffer from claustrophobia.
  • Bring medication along that you may need for the investigation e.g. pain-relief/anti-anxiety medication. If you think you may need a sedative/anti-anxiety medication for the investigation, please make sure you have someone that can drive you home after the investigation.
  • Inform the radiographer if you are pregnant (or think you may be), breastfeeding or have any allergies.
  • Movement disorders: Certain medications need to be withheld for a duration of time, these are only neurological/psychiatric medications and include:
  • Talcopone (Tasmar®) at least 15 hours, Entacapone (Comtan®Stalevo®) at least 15 hours and Reserpine (Reserpine®Rinerdin®) 20 days.

 

APPROPRIATE INDICATIONS FOR PET/CT REFERRALS

PET-CT is currently the most widely used molecular imaging technology for a patient-tailored treatment approach. These recommendations outline which oncological and non-oncological indications are appropriate for PET/CT. Once each combination of pathology and clinical indication is defined, a recommendation is given as:

  1. Recommended;
  2. Recommended in select cases;
  3. May be considered; or
  4. Not Recommended.

View Here: PET/CT indications

 

ONLINE REFERRAL FORM