Surgical Techniques
particles and the blue dye are taken up by macro-
phages; this point is illustrated in Chap.10 and
in
Chap. 11, case no. 16.
Sentinel Node Detection in Breast Cancer
The surgical techniques used in the
intra-operative
detection of the sentinel node have varied
signifi-
cantly, ranging from blue dye lymphatic mapping
alone to probe-guided surgery alone or in com-
bination with the blue dye technique. Giuliano et
al. [3] performed lymphatic mapping by using
isosulfan blue vital dye, which was injected in a
peritumoral fashion into the breast parenchyma in
174 patients.A success rate of 65% and a
sensitivity
of 75% were reported, although higher success
rates were subsequently achieved with experience.
In a pilot study performed by Krag and associates
[4] the technique of probe-guided localisation of
the radiolabelled sentinel node was introduced
after their initial success in staging patients
with
melanoma [5,6].The success rate of this technique
was 82 %, with a predictive accuracy of 100 %. In
a
study performed by Albertini and associates [7],
combining the blue dye technique and probe-
guided surgery in 62 patients,a success rate of
92%
was reported, with 100% accuracy in predicting
the axillary node status. These authors concluded
that the addition of the gamma detection probe
increased the success rate from 73% to 92%, as in
12 patients blue dye did not appear in the lymph
nodes but focal hot spots were detected by the
probe. A higher detection rate of 98% was re-
ported by Veronesi and co-workers [8], with a
false-negative rate of 5.4%, after subdermal in-
jection of colloidal albumin and probe-guided
Introduction
With the sentinel node technique gaining pop-
ularity as an important and minimally invasive
staging procedure in surgical oncology, there is
renewed interest in the structure and function of
the lymphatic system.The lymph nodes are highly
specialised immunocompetent organs which are
located along the length of lymphatic vessels [1].
Each lymph node is covered by a capsule of dense
connective tissue that extends strands called tra-
beculae into the node, dividing it into several
com-
partments. Within the lymph node parenchyma
there are two main regions: cortex and medulla.
The outer cortex contains many lymphoid follicles,
which are regions of densely packed lymphocytes.
T
lymphocytes and macrophages and follicular
dendritic cells which participate in the activa-
tion of T cells are located on the outer rim of these
lymphoid follicles. The germinal centre is the
lighter staining central area of a follicle where
B
lymphocytes proliferate into antibody-secreting
plasma cells [2]. The inner region of a lymph
node is the medulla. Here lymphocytes are tightly
packed in strands called medullary cords. Lymph
flows through a node in one direction. It enters
through the afferent lymphatic vessels, which
penetrate the convex surface of the node at
several
points [2].
Lymph enters the subcapsular sinus and then
through cortical and medullary sinuses exits the
lymph node via one or two wider efferent lym-
phatic vessels. These lymphatic sinuses contain
numerous macrophages [1]. The lymph node fil-
ters foreign substances which can be trapped by
the reticular fibres within the node. Macrophages
may destroy these by phagocytosis and lympho-
cytes also play a role in the immunological re-
sponse. In the sentinel node context the colloidal
chapter
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