Sentinel lymph node biopsy
Sentinel lymph node biopsy is a diagnostic
technique used to determine if breast cancer has spread
(metastasised) to the lymph nodes in the axilla.
Research has shown that the lymph ducts in the
breast usually drain to just one or two lymph nodes (the Sentinel
nodes) before draining through the other nodes in the armpit
(axilla). If there are cancer cells in the lymph fluid draining
from the breast they will go to the sentinel node and ultimately
migrate to the other nodes In a sentinel node biopsy
the sentinel node is identified and removed for histological
examination. If no cancer cells are detected in the sentinel node
this suggests that the cancer is localised and has not spread and
that a full axillary clearance (removal of all the lymph nodes in
the armpit) may be unnecessary.
Minimising the extent of surgery and the
preservation of uninvolved lymph nodes is highly desirable. There
are a number of undesirable side effects associated with lymph
node
surgery including arm swelling (lymphodema)
and associated arm and shoulder
weakness and/or numbness.
If you are undergoing a sentinel node biopsy
prior to your operation a small amount of a radioactive substance
(a tracer) will be injected into your breast. This radioactive
substance will migrate into the sentinel node and allows it to be
identified by the surgeon using a small scanning device which
detects the radioactive substance that has accumulated in the node.
Sometimes a blue dye is injected at the same time which also
assists in identification of the sentinel node. The amount of
radioactive substance used is very small and does not present any
risk to your health.
Once the sentinel node has been located the
surgeon will make a small incision and remove the sentinel node for
examination in the laboratory by a histopathologist. If no cancer
cells are found then no further surgery is normally necessary.
However if there is evidence of cancer cells the surgeon may
proceed to a full axillary dissection to remove all the nodes in
the area or may recommend a course of radiotherapy.
Although sentinel lymph node biopsy is now
recognised as a reliable and less invasive method of assessing
axillary lymph node involvement in breast cancer, it is not an
appropriate technique for all patients. It is generally most
appropriate for women with early stage disease with a relatively
low risk of lymph node involvement.
It is important to use a surgeon who has
considerable experience with the technique. At The London Clinic we
not only have surgeons with extensive experience of this technique
but we have the benefit of a full equipped nuclear medicine
department as well as an experienced team of breast
histopathologists.