Sentinel Node Biopsy
- A New Advanced Procedure in Breast Cancer
Sentinel node biopsy is a new technique
which can be used in some patients undergoing surgery
for breast cancer. Lymph nodes located in the axilla
(armpit) on the side of a breast cancer are one of the
first places that cancer may spread to. The “sentinel”
node is the first in a chain of lymph nodes that drains
the breast. A sentinel lymph node biopsy involves the
removal of one to three lymph nodes, for assessment
by a pathologist. If these sentinel nodes do not contain
cancer cells, it may be possible to avoid more extensive
surgery.
The sentinel node can be identified
using blue dye or a small dose of a low-level radioactive
tracer which can be looked for in the nodes. Research
has shown that it is best to use both techniques together.
Both the blue dye and the radioactive tracer solution,
which contains less radiation than a standard x-ray
and emits gamma rays, are injected around the nipple
area before the operation.
Once the tracer and dye have reached
the nodes, the surgeon scans over the axilla to locate
the sentinel nodes with an electric, hand-held gamma
ray counter (called a Geiger counter). Once the sentinel
node is located by measuring where the radioactivity
is the strongest, the surgeon can, through a small incision,
look for nodes containing blue dye and remove them for
a pathologist to examine and analyse under a microscope.
Several clinical trials have shown
that in most cases, if the sentinel node does not contain
cancer cells, then the cancer has not spread past the
breast. Surgery removing lymph nodes in the axilla may
then not be necessary. This can prevent some of the
complications of more extensive surgery such as lymphoedema
(swelling), cellulites (infection), altered sensation
and restricted movement in the arm.
Sentinel node biopsy is a new technique.
The ultimate goal is to remove as few lymph nodes as
possible in patients with breast cancer suitable for
this procedure in order to reduce the complications
than can occur when lymph nodes in the axilla are removed.
Dr Iain
Lyburn
10th April 2005
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