Transcript Sentinel Nodes

Sentinel Nodes
J.R.Buscombe
RFH
Sentinel Nodes
Uses the Morton principle of logical lymph
drainage from a tumour
 Methods use include blue dye and
radiotracers
 Combination of 2 may be best
 Pioneers in breast
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Morton/Krag/Guilianno USA
(EIO, Italy and AMC, Netherlands)
In Melanoma-Morton/Guilianno
May replace high morbidity axillary clearance
Sentinel nodes
Tumour
Sentinel (1st
node)
2nd and 3rd order
nodes
•Morbidity of Axillary Surgery
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Seroma 50%
Lymphoedema 10-30%
Severe ICBN neuralgia 5%
Shoulder-girdle dysfunction
20%
Numbness 80%
Lymphoedema rates:
RT alone :
Sampling:
Level III clearance
Surgery + RT:
10%
10%
30%
70%
Sentinel nodes
Sentinel nodes
Methods all similar
 Depends on injecting radiotracer in or
near cancer
 Using gamma camera and probing to
track tracer through lymphatics
 Intra-operative probe to remove the
sentinel node
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Sentinel node
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Controversies
Who to inject
 Where to inject
 How much to inject
 How much activity to inject
 What colloid to use
 When to operate
 Training
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Injection technique is
standardised: Intradermal
Periareolar,tumour quadrant
Different injection sites (intradermal,
subareolar and peritumoural) have
advantages and disadvantages
depending on the desired effect on
the pattern and kinetics of lymphatic
drainage. NEWSTART is designed to
minimise visualisation of IMN
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Activity injected will depend on the
time from injection to surgery
Massage post injection
Size matters
The size of a colloid may have an effect
on its transit
 However not simple as charge and
flexibility of the colloid may change
transit
 Remember the lymph system is a
complex transit system and may be
affected by many factors
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What size then?
No perfect colloid for sentinel node
scintigraphy
 All colloids designed for another job
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Nanocol – infection imaging
 Albures – lymphoscintigraphy
 MAA – lung scanning
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How colloids made?
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Normally made from albumin
Man
 Cow
 Pig
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Often heated to form clusters
 May be spun
 Can vary in size by factor of 10
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Types of colloids used
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Tc-99m antimony colloid
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Tc-99m sulphur colloid-filtered
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4-100 nm
Tc-99m HAS Albures
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50-100 nm
Tc-99m HSA-nanocoll
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3-30 nm
200-2000 nm
Tc-99m MAA
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>5000nm
Optimal colloids
Will pass to sentinel node and stay
there
 Smaller colloid will pass through so
multiple nodes seen
 May clear form sentinel node totally so
no counts if >4 hours post injection
 Frequent imaging helps
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What to inject?
Intra-operative probing
If using small colloids should be done
within 4 hours post injection
 Larger colloids can be done at 24 hours
 During imaging mark site of sentinel
nodes on the skin in two planes
 External probing can help pre-op
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Intra-operative probing
About 20 different probe types available
 Different crystals have different
sensitivities
 Most use CdTe, CsI, NaI BiGeO crystals
 Needs good collimation to prevent
activity passing through the side of the
probe
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Probing the node
Intra-operative probing
Inject blue dye at site of tumour just
before operation
 Use blue dye to help find lymphatics
 Probe along blue dye tract until signal
high
 Remove node send to histology
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Use of blue dye and radio-tracer
Probe box
Sentinel nodes
Results
 Pagenelii’s group from Milan
 Over 400 patients 98% successful
identification of sentinel node
 Caution from USA (Krag et al) High
variability in results surgeon to surgeon
(64-100% PPV)
 Issues of training/audit ALMANAC
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Potential problems
Injection incorrect (intradermal)
 Breast not massaged
 Colloid too small/big (manafcturer’s QC)
 Probing performed badly so node
missed
 Poor collimation means signal swamped
 Problems with histology etc
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Areas where problems seen in
breast cancer
Multifocal/centric tumours (maybe
helped by nipple injection)
 Find this disease with Tc-99m MIBI or
MRI
 Previous surgery around primary
 Breast irradiation
 Neo-adjuvant chemotherapy
 Vascular invasion of tumour
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MRI and Tc-99m MIBI
Sentinel nodes
Can it replace axillary clearance as a
staging procedure
 Need to await phase III trials
 Patients with T1N0 randomised to ax
clearance or sent node
 Who has better morbidity
 Any difference in survival
 Need 5 year follow-up
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Results in Melanoma
Published by Morton’s group
 Reviewed results of 1900 patients
having sentinel node for melanoma
 All had blue dye and colloid
 All had Breslow thickness greater than
5mm
 Recurrence rate measured at a mean of
7 years
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Does sentinel node effect
outcomes?
Morton’s review
 Ann Sur Onocol
2000
 1900 patients
 Sentinel node vs
blind wide local
excision
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60%
50%
40%
30%
20%
10%
0%
SN
WLE
How is melanoma sentinel node
different?
Melanoma can occur anywhere
 Drainage much more variable
 May drain to more than one set of nodes
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Head and neck
Trunk
Different speeds of flow
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Leg 20-30 minutes
Head 60-120 minutes
Method-melanoma
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Normally done after removal of primary
Aim to identify correct block of lymph nodes
to disect
Inject at 4 pints around scar of excision
Inject at least 5mm away from the scar
Massage gently
Image draining nodes
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Calf-groin
Back Both inguinals and both upper thorax
Injection for melanoma
Melanoma-methods
Mark any node found
 Use shadow gram and laterals and
obliques help surgeon identify node
 In op use blue dye to find lymphatics
and direct surgeon to node
 Surgeon the removes sentinel and
associated nodes
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Melanoma in the leg
In leg passage fast up into
groin, as the groin nodes are
the draining nodes the
sentinel node is in the groin
The popliteal nodes are
ignored
Melanoma on crest of head
covered by lead; note bilateral
sentinel nodes
Other sites in which sentinel
node can be used
Melanoma – all patients as variable
drainage
 Penis
 Tongue
 Head and neck
 Vulva
 Colon!
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NEW START
Sentinel Lymph Node
(SLN) training
programme
NEW START
SLN training programme 2004-2006
Joint Project
Department of Education: Royal College of
Surgeons of England
 Cardiff University Wales
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Supported by
 DoH, National Assembly in Wales
 GE Healthcare
 BNMS
NEW START
SLN training programme
National Training Programme
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Standardised methodology and training materials
Focus on multidiscipline team – Surgery, Nuclear medicine/physics,
Radiology, Theatre nurses, Pathology, etc
Experienced validated training teams
 Unique workplace training and mentorship
 Quality assured
 Centrally audited and validated (anonymised data collection)
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NEW START SLN training
programme:
Standardized National Training
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World wide trials* have shown ad-hoc adoption of
SLNB, with little formal training, reduces the accuracy
of SLN identification for the first 50 procedures.
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Evidence from the UK ALMANAC trial demonstrates
that structured training shortens the learning curve to
less than 10 procedures.
* Cox et al: Annals Surg. Oncol.1999, vol l6, page 6
NEW START SLN training
programme Overview
3 training phases
1.Theory
Day
In House
Training
Validation
Stand alone
Theory
Skills
SLNB + standard procedure
Projected Time frame:18-24 months
SLNB
Conclusion
Sentinel node study established in
melanoma and breast
 Useful in reducing mutilating surgery
 Simple to learn technique but needs
good colloid and good probe
 Can be combined with other NM test
such as PET and scintimammography
 All members of the team important
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