1. Sentinel Nodes
J.R.Buscombe
RFH

2. 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
Morton/Krag/Guilianno USA
(EIO, Italy and AMC, Netherlands)
In Melanoma-Morton/Guilianno
May replace high morbidity axillary clearance

3. Sentinel nodes
Tumour
2nd and 3rd order nodes
Sentinel (1st node)

4. Morbidity of Axillary Surgery
Seroma 50%
Lymphoedema 10-30%
Severe ICBN neuralgia 5%
Shoulder-girdle dysfunction 20%
Numbness 80%
Lymphoedema rates:
RT alone : 10%
Sampling: 10%
Level III clearance 30%
Surgery + RT: 70%

5. Sentinel nodes

6. 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

7. Sentinel node Controversies Who to inject Where to inject
How much to inject
How much activity to inject
What colloid to use
When to operate
Training

8. 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
Activity injected will depend on the time from injection to surgery
Massage post injection

9. 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

10. What size then? No perfect colloid for sentinel node scintigraphy
All colloids designed for another job
Nanocol – infection imaging
Albures – lymphoscintigraphy
MAA – lung scanning

11. How colloids made? Normally made from albumin
Man
Cow
Pig
Often heated to form clusters
May be spun
Can vary in size by factor of 10

12. Types of colloids used Tc-99m antimony colloid
3-30 nm
Tc-99m sulphur colloid-filtered nm
Tc-99m HSA-nanocoll
4-100 nm
Tc-99m HAS Albures nm
Tc-99m MAA
>5000nm

13. 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

14. What to inject?

15. 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

16. 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

17. Probing the node

18. 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

19. Use of blue dye and radio-tracer

20. Probe box

21. 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

22. 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

23. 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

24. MRI and Tc-99m MIBI

25. 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

26. 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

27. Does sentinel node effect outcomes?
Morton’s review
Ann Sur Onocol 2000
1900 patients
Sentinel node vs blind wide local excision

28. How is melanoma sentinel node different?
Melanoma can occur anywhere
Drainage much more variable
May drain to more than one set of nodes
Head and neck
Trunk
Different speeds of flow
Leg minutes
Head minutes

29. Method-melanoma 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
Calf-groin
Back Both inguinals and both upper thorax

30. Injection for melanoma

31. 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

32. 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

33. Melanoma on crest of head covered by lead; note bilateral sentinel nodes

34. Other sites in which sentinel node can be used
Melanoma – all patients as variable drainage
Penis
Tongue
Head and neck
Vulva
Colon!

35. NEW START Sentinel Lymph Node (SLN) training programme

36. NEW START SLN training programme 2004-2006
Joint Project
Department of Education: Royal College of Surgeons of England
Cardiff University Wales
Supported by
DoH, National Assembly in Wales
GE Healthcare
BNMS

37. NEW START SLN training programme
National Training Programme
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)

38. NEW START SLN training programme: Standardized National Training
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.
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

39. NEW START SLN training programme Overview
3 training phases
1.Theory Day
In House Training
Validation
Stand alone
SLNB
Theory
Skills
SLNB + standard procedure
Projected Time frame:18-24 months

40. 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