Scintigraphy of the sentinel lymph node
A sentinel lymph node scintigraphy is used to localize and mark the sentinel lymph node. This is the first lymph node in the lymphatic drainage area of a tumor. Scintigraphy is performed before the planned surgery using a low-level radioactive substance.
approx. 60 min
Duration of examination
> 95 %
Sentinel lymph node marking success
About one fifth
of the natural annual Amount of radiation
Where can you have a scintigraphy of the sentinel lymph node performed in Munich?
We offer nuclear medicine labeling of the sentinel lymph node at our location in the Rotkreuzklinikum in Nymphenburgerstr. 163 an.
When is sentinel lymph node scintigraphy useful?
The principle of sentinel lymph nodes is based on the idea that in primary lymphogenic metastatic tumors there is an orderly outflow of lymph from the tumor region into a first lymph node (sentinel lymph node = sentinel lymph node).
The status of the sentinel lymph node, i.e. whether it is affected by tumor cells or not, is important for further therapy planning and prognosis. Sentinel lymph node scintigraphy can identify the sentinel lymph node > 95% of the time, so that the surgeon can easily find and remove this one or more sentinel lymph nodes by radioactive labeling using a so-called gamma probe. The extent of surgery can be minimized. The pathologist now examines this lymph node to determine whether it is affected by tumor cells.
The sentinel lymph node scintigraphy is usually only useful in the early stages of a disease, in which at most a so-called micrometastasis is to be expected, i.e. an infestation by a few tumor cells has occurred without the lymph node having changed visibly (e.g. ultrasound) or even palpably.
Sentinel lymph node scintigraphy is used for the following tumors:
- Breast Cancer
- Melanoma
- Vulvar carcinoma
- Cervical Cancer
How does a sentinel lymph node scintigraphy work?
Sentinel lymph node scintigraphy uses a 99m technetium-labeled colloid with a very small particle size (20-100 nm). These are transported via the lymphatic channels, which form a very fine network, to the first lymph node in the outflow area (= guardian lymph node) and accumulate here.
The gamma camera is then used to image the radioactively labeled lymph node. The method is only used to mark the lymph node for the surgeon and cannot tell if it is affected by the tumor. For this, the pathologist’s examination of the lymph node to be surgically removed is crucial.
What do you need to know before the treatment?
You do not have to be sober. Please wear comfortable clothing; a bra must be removed beforehand for lymph node marking in the case of a tumor of the mammary gland. The test substance consists of very small human albumin particles (=protein) labeled by 99m-technetium and must not be used if you are hypersensitive (allergic) to albumin-containing drugs.
What is the procedure for a sentinel lymph node scintigraphy at Radiologie München?
After skin disinfection, the examination substance is injected very superficially with a very small and thin needle into the skin of the mammary gland or around the tumor while the patient is lying down. You will notice a slight feeling of pressure. We will then accompany you to a rest area and show you how to support the lymphatic drainage by means of a light hand massage.
You will lie on the gamma camera for about 5 minutes for the exposures. Sometimes the lymphatic drainage may be very slow and we may have to repeat the imaging at a later time, possibly injecting some of the examination substance again. Heat compression can be used in an additional attempt to stimulate lymphatic drainage.
If the sentinel lymph node shows up on the images, its location can be marked on the skin with a pen at the surgeon’s request. Please do not wash off this mark. The operation is performed either on the day of the examination itself or the next day. If necessary, we will give you a so-called gamma probe, which the surgeon needs to find the sentinel lymph node
What are the risks and side effects of sentinel lymph node scintigraphy?
The test substance must not be used if you are hypersensitive (allergic) to protein or drugs containing human albumin. Side effects are rare; there are reports of allergic reaction (hypersensitivity) to protein and very rarely local reactions.