Lucien Kaarse of the Nuclear Medicine Department (Drs Visser, Erasmus, Vawda and Partners, Radiologists) provided the following helpful FAQ for patients undergoing a “sentinel node” scan prior to surgery which will test the lymph nodes following a cancer diagnosis, and/or remove them.
What is a sentinel node scan?
A sentinel node scan is used to identify ‘sentinel’ lymph nodes. These are the first lymph nodes in a group that receive the lymph from a particular area of the body. The scan is carried out in preparation for your sentinel lymph node biopsy later on the same day, or the following day.
How does the scan work?
A tiny amount of radioactivity called a tracer will be injected into the skin around the primary site of the cancer. You are then positioned under a scanner called a gamma camera. The tracer moves from the injection site through the lymph vessels to the lymph nodes. The positions of the sentinel nodes will be marked on the skin surface. This identifies those nodes which your surgeon may want to remove.
Is there any preparation for the scan?
• You must tell us in advance if you know you are (or think that you may be) pregnant, or are breast feeding.
What happens during the scan?
• Our staff will explain the procedure to you fully when you arrive for your appointment.
• We will then ask you to lie on the scan bed. We will make sure you are as comfortable as possible for the scan, as is it extremely important that you remain as still as you can.
• While you are lying on the bed we will inject a very small amount of the tracer into the skin around the site of the cancer.
• You will then be positioned under the scanner and we will take the first pictures for up to 30 minutes. Following that we will take several more pictures, from the front and the side.
• When we have seen the sentinel node/s, we will mark the position on your skin with a permanent pen.
• Most scans take about one hour, but if we have not seen the node/s, you may be asked to return later in the day for further pictures to be taken.
Will I feel anything during the scan?
Having the injection will sting momentarily but there are no side effects from the injection and it will not make you feel sleepy or affect your ability to drive. Having the pictures taken will not hurt.
What happens after the scan?
When we have checked the technical quality of your scan and are happy we have all the information we need, you will be able to leave the department. After the scan is reported, the results will be sent to your surgeon before you have the operation.
How safe is the examination?
There are no specific risks associated with this procedure.
What are the benefits of the scan?
A sentinel node scan is only one part of a procedure called sentinel lymph node biopsy, which is a surgical technique for finding out how far some types of cancer have spread (staging). It helps the surgeon looking after you to identify and locate those nodes which they may want to remove. Your specialist surgeon will already have discussed with you the benefits of having a sentinel node scan.
What happens if I decide not to have the scan?
If you decide not to have the scan, then please discuss this with the surgeon who is looking after you.
What happens if I cannot keep my appointment?
If you cannot keep your appointment, please contact the nuclear medicine department as soon as possible.