This leaflet describes the contrast agents (dye) that are used for your Radiotherapy planning scan, why they are needed and what to expect.
Asking for consent
The Radiographer or Clinical Assistant will ask you some questions to see if it is safe to administer dye. You will be asked to sign a form to give your permission for the procedure. It is your decision, and you can change your mind at any time. Please ask the Radiographer any questions you have at the time.
You will receive the following contrast agent/s (dye):
- Omnipaque – Oral
- Omnipaque – Intravenous
- Omnipaque – Intravenous and Oral
- Gadolinium – Intravenous
OMNIPAQUE 300
What is it and why is it used?
Omnipaque is a specific type of dye which makes blood vessels and some organs easier to see on CT images. This is helpful for the planning and delivery of Radiotherapy. Very occasionally, you may be asked to drink a small amount of contrast prior to your Radiotherapy treatment.
How is it given?
- Orally: You may be asked to drink water mixed with a small amount of dye. It does not have an unpleasant taste.
- Intravenously: Delivered via a very small plastic tube called a ‘cannula’ into a vein in your hand or arm by a Radiographer during the CT scan.
Possible side effects?
When the dye is given through your cannula you may experience some normal sensations which the Radiographers will discuss with you. These include:
- a warm sensation around your body
- a feeling like you are emptying your bladder (you aren’t)
- a metallic taste in your mouth
If you are asked to drink water with dye, it is unlikely that you will experience any side effects at the time. Sometimes it can make you feel nauseous/sick or affect your bowels (make them loose) afterwards.
Very rarely, patients may have a serious reaction to dye when injected. The Radiographers will explain everything about the procedure. However if you have pain around the injection site, nausea, vomiting, itching or a rash, you may be having a reaction.
The Radiographers keep a close eye on you to ensure your safety: It is important to let them know if you feel unwell or something does not feel right.
GADOLINIUM
What is it and why is it used?
Gadolinium-based dyes are used in Radiotherapy MRI planning scans. These are:
- Clariscan® / Dotarem® (Gadoteric acid) is used for Brain, Head and Neck imaging
- Primovist® (Gadoxetic acid) is used for Liver imaging
Gadolinium-based dyes are used to make it easier to see vessels inside your body, and helps the doctor see the area they want to treat more clearly.
How is it given?
- Intravenously: Delivered via a very small plastic tube called a ‘cannula’ into a vein in your hand or arm by a Radiographer during the MRI scan.
Possible side effects?
Gadolinium may cause side effects in some people, but they are usually mild and will not last long.
Common reactions to both Omnipaque and Gadolinium are:
- injection site pain
- nausea
- vomiting
- itching
- rash
Advice:
Most reactions happen straight away or within an hour of the dye being given; however, some can occur up to several days later.
In the rare event you develop any of the following symptoms then you must seek urgent medical advice:
- swelling of the face, mouth, hands, feet or throat
- difficulty breathing or swallowing.
- fainting
- coughing, wheezing, sneezing
- eye irritation
- rashes / hives / itchy red skin
Contact either an Emergency Doctor (Walk-in Centre or A&E) or the NHS Helpline (online: 111.nhs.uk or telephone: 111 from a landline or mobile).
Please keep hold of this leaflet in case you develop a reaction as it is a record of what you have received.
Please inform staff at any future scans if you have suffered a reaction to dye, whether minor or more severe.