1. Lateral neck dissection for papillary thyroid cancer
Joint hospital Surgical Grand Round
19 October 2013
Dr. Dennis CT Lam United Christian Hospital
Good morning, chairman, senior sand colleague, the topic of my presentation today is lateral neck dissection for papillary thyroid cancer

2. Outline Introduction Lateral neck dissection (LND) for PTC
Indication of LND
Extent of LND
Morbidity of LND
Conclusion
The outline of presentation will be from the introduction of LND, then I will discuss about the indication, extent and morbidity of lateral neck dissection one by one.

3. Introduction
Papillary thyroid cancer (PTC) composed of 77-85% of thyroid malignancies
Strong propensity for regional LN involvement
Papillary thyroid cancer is the most commonest subtype of thyroid malignancy.
It consisted of up to 85 percent of all thyroid malignancy.
As we all know it has a strong tendency to have regional LN metastasis.
A National Cancer Data Base report on 53,856 cases of thyroid carcinoma treated in the U.S., 1985–1995.
Hundahl SA, et al. Cancer 1998.

4. Anatomy of Cervical Lymphatic
Here is the anatomy of the cervical LNs.
In talking about the neck dissection for Ca thyroid we mainly focus of the central compartment which is the level 6 LN
And also the lateral compartment which includes level 1 to 5 and it is the focus of my presentation today
The boundary of the 2 compartment is the common carotid artery, everything lateral to CCA is lateral compartment LN.
American Thyroid Association Guidelines Taskforce on Thyroid Nodules and Differentiated Thyroid Cancer

5. LND in PTC Papillary thyroid cancer (PTC)
Lateral neck dissection (LND)
To dissect/ not to dissect
Extent of dissection
Indeed CND has been discussed in previous GR and it is another big topic for ca thyroid.
My focus today will be on the indication and extent of lateral neck dissection

6. Patterns of Nodal Metastases
Central compartment
Lateral compartment
Contralateral neck
The pattern of LN met for PTC is known to firstly affect the central compartment then the lateral compartment in the ipsilateral side, and then affecting the contralateral neck LNs
Pattern of lymph node metastases in papillary thyroid carcinoma.
Gimm O, et al. Br J Surg 1998.

7. Usual scenario Lateral compartment +ve Central compartment +ve
Tumor in middle and lower poles
From this usual mode of spread, when there is presence of LN met in lateral compartment there is usually presence of central compartment LNs.
And it happened to be in the cases of middle and lower pole tumor which also compatible to the anatomy of the venous drainage
Lymph node dissection in the lateral neck for completion in central node-positive papillary thyroid cancer.
Machens A, et al. Surgery 2009.

8. Concept of skip metastasis
Lateral compartment +ve
Central compartment –ve
Tumor in upper pole
However there are certain portion of patient who had skip metastasis which violate the usual mode of LN met
Ie if they have lateral compartment LN metastasis without central compartment LN involvement.
This is usually in the case of upper pole tumor which has a stronger preference to met to upper jugular LNs first than central compartment
This study of 147 patients with papillary thyroid cancer found skip metastases in 32 patients (21.8%)
Skip metastases occurred commonly with primary tumors of the upper pole, and with tumors of 1 cm or less in diameter
Skip lateral neck node metastases in papillary thyroid carcinoma Park JH, et al. World J Surg 2012.

9. Patterns of Nodal Metastases
7%-19% skip metastasis
In various study showed that skip metastasis indeed is not uncommon, and it happened that 7 to almost 20 percent of cases demonstrated skip met
Central cervical nodal metastasis from papillary thyroid microcarcinoma: pattern and factors predictive of nodal metastasis Roh JL, et al. Ann Surg Oncol 2008.

10. Detection and Diagnosis
Physical examination
Ultrasonography
FNA cytology
After confirmation of the diagnosis of PTC and with the pre op assessment, it is mandatory to have a pre op USG neck to detect suspicious LNs and plan the extent of lymphadenectomy.
FNAC of any suspicious LN should be done
And if LN is small, FNAC washout and analysis of thyroglobulin level is also useful in identification of LN met

11. Significance of LN metastasis
Loco-regional recurrence
Risk factor for local regional recurrence
Distant metastases
Predictor of systemic disease
Reflective of more advanced or aggressive tumor
Survival
Lower long term survival rates in patient with LN metastasis
The reason why we have to deal with LN metastasis is because it is a risk factor for local recurrence.
It is also a predictor of a systemic disease and reflect a more advanced stage tumor.
Most importantly it is associated with a lower long term survival according to recent studies.

12. To dissect/ not to dissect?
So what is the indication of lateral neck dissection, when should we dissect the lateral compartment?

13. Therapeutic / Prophylactic
Therapeutic dissection
Presence of clinically positive LNs
Prophylactic dissection
Absence of clinically positive LNs
To clear occult LN metastases
Controversial, as lack of evidence to improve survival
There are 2 main concepts.
Therapeutic dissection mean the neck dissection when there is clinically positive LN either suspicious on USG or confirmed on FNAC, and it is sensible.
Prophylactic dissection mean neck dissection when there is no clinically positive LN.
And it aims to clear the occult metastases that are found in 15% of USG-negative patients
However prophylactic dissection is very controversial and there is no high level of evidence to show that it improve survival
Occult met 15%

14. Prophylactic dissection
Primary tumor located in the upper pole
Extensive involvement of the ipsilateral central compartment
A review earlier this year suggest prophylactic dissection in patient with upper pole tumor in view of the concept of skip metastasis, also patient with extensive involvement of ipsilateral central compartment should have lateral dissection due to the risk of higher chance of lateral compartmental metastasis. However it is not based on high level of evidence.
Surgical management of the lateral neck compartment for metastatic thyroid cancer.
Dralle H, et al. Current Opinion in Oncology. 25(1):20-6, 2013 Jan.

15. High risk patient group
Older age
Male gender
Extra-thyroidal extension
Tumor multi-focality
Tumor calcification
Larger tumor size
Advanced stage tumor
Central node positivity
Another clinical guideline published 2010 suggest prophylactic dissection in certain high risk group patient including …
Again we have to be extremely caution in embarking on prophylactic dissection. In fact it should not be routinely performed due to lack of evidence of potential complication.
Surgical management of cervical lymph nodes in differentiated thyroid cancer
Danielle Fritze, et al. Otolaryngol Clin N Am 2010.

16. Extent of lateral neck dissection
So what should be the extent of lateral neck dissection?

17. Extent of lateral neck dissection
Selective ‘berry picking’ is associated with higher rates of loco-regional recurrence and has been largely abandoned
Isolated selective berry picking of LN is associated with a high rate of local regional recurrence. Therefore a systematic compartmental neck dissection should be performed instead of just a isolated LN resection
Greater local recurrence occurs with ‘berry picking’ than neck dissection in thyroid cancer.
Musacchio MJ, et al. Am Surg 2003; 69:191–196.

18. Supra-hyoid dissection (Level I)
Less than 5% of patients had supra-hyoid involvement in patients with lateral cervical metastases
Not routinely included in lymph node dissections unless there is macroscopic involvement
Level I dissection is not commonly done as less than 5% of patient had supra hyoid involvement in patients with PTC. Therefore it is only included unless there is macroscopic involvement.
Lateral cervical lymph node metastases from papillary thyroid carcinoma: pattern of nodal metastases and optimal strategy for neck dissection.
Roh JL, et al. Ann Surg Oncol 2008;15(4):1177–82.

19. Most lateral compartment dissections routinely encompass levels II–V
Gold standard of a lateral compartmental dissection routinely include level 2 to level 5
That is lymphadenectomy of the jugular chain and posterior triangle
Patterns of lateral neck metastasis in papillary thyroid carcinoma.
Kupferman ME, et al.
Arch Otolaryngol Head Neck Surg 2004

20. LN compartment are further subdivided into subgroup
The important landmark in this division is the CN11. spinal assessor nerve.
Which divided 2 into 2a which is anterior/ inferior to CN11 and 2b which is superior and posterior
Level V is divided into Va and Vb by the level of cricoid and subdivision of level Va into Vas and Vai but its clinically less irrelevant.

21. This is a table showing the percentage of LN involvement for metastatic papillary CA in a few large retrospective study
And I translate the figure into this bar chart
Lateral cervical lymph node metastases from papillary thyroid carcinoma: pattern of nodal metastases and optimal strategy for neck dissection Roh JL, et al. Ann Surg Oncol 2008.
Tumor above the spinal accessory nerve in papillary thyroid cancer that involves lateral neck nodes: a common occurrence Pingpank JF Jr, et al. Arch Otolaryngol Head Neck Surg 2002.
Regional metastases in well-differentiated thyroid cancer: pattern of spread Yanir Y, et al. Laryngoscope 2008.

22. Which u can appreciate apart from central compartment.
Level 2a and 3, 4 are most commonly involved in metastasis
Level 1 and 5 are rarely involved

23. Level IIa, III, IV
Levels IIa, III, and VI were each involved in more than 70% of patients
⃝⃝⃝⃝this is supported by a few retrospective studies.
This study showed that 2a, 3, 4 are involved in more than 70 percent met in ca papillary thyroi
Lateral cervical lymph node metastases from papillary thyroid carcinoma: pattern of nodal metastases and optimal strategy for neck dissection.
Roh JL, et al. Ann Surg Oncol 2008.

24. Cervical lateral neck metastases in PTC occur in a predictable pattern, with levels III, IIa, and IV most commonly involved
And it is actually met in a predictable pattern according to anatomy
It is quite compatible to the lymphatic drainage of the thyroid gland is having a close proximity to the jugular chain than in post triangle.
Anther retrospective studies also showed that level 2a, 3, 4 are most commonly involved.
Is routine dissection of level II-B and V-A necessary in patients with papillary thyroid cancer undergoing lateral neck dissection for FNA-confirmed metastases in other levels.
Farrag T, et al. World Journal of Surgery. 33(8):1680-3, 2009 Aug.

25. Level II
But how about level 2a and 2b, any differences?

26. Level IIb Only 16.7% of patients had positive nodes at level IIb
Involvement was associated with multilevel disease in all cases
We can appreciate that 2a is commonly involve in met but differently surprisingly only 16.7% of patient had + node in 2b
And involve in 2b is asso with multi level disease , and more advanced disease ie
Lateral cervical lymph node metastases from papillary thyroid carcinoma: pattern of nodal metastases and optimal strategy for neck dissection.
Roh JL, et al. Ann Surg Oncol 2008;15(4):1177–82.

27. Level IIb
‘’….the incidence of LN metastases at level IIb was 2.1% the results of the present study suggested that LN metastases in level IIb are rare in patients with PTC undergoing neck dissection’’
Retrospective review
Rate of level Iib is low involvement, suggest rare involvement for IIb
Level IIb lymph node metastasis in thyroid papillary carcinoma.
Vayisoglu Y, et al. European Archives of Oto-Rhino-Laryngology 2010.

28. Level IIb
‘’…level IIb was positive in 8.5%…elective dissection of level IIb only when level IIa is involved, based on FNA confirmation, or when it is grossly involved on intraoperative evaluation’’
Another retrospective study on patient with PTC undergo LND from level II to V
Level Iib met only in 8.5 percent with 2a 60% and all 2b met are asoo with 2a met
So they recommend a level 2b dissection only when 2a is involve
Is routine dissection of level II-B and V-A necessary in patients with papillary thyroid cancer undergoing lateral neck dissection for FNA-confirmed metastases in other levels.
Farrag T, et al. World Journal of Surgery. 33(8):1680-3, 2009 Aug.

29. Level V
Level V is also a controversial area on the extent of dissection and it involve a larger area which the CN11 cross its upper aspect.

30. Level V
‘’Level V lymphadenectomy may be considered in patients with lymph node metastasis in the ipsilateral lateral neck with macroscopic extranodal extension’’
What is extranodal extension?
This retrospective study showed that compare with 2 3 4, level 5 involvement is only 18 percent.
By uni variate analysis of other variables they showed that macroscopic nodal extensions is asso level V met
So they conclude that ……
Preoperative detection and predictors of level V lymph node metastasis in patients with papillary thyroid carcinoma
Kirkby-Bott J. British Journal of Surgery. 100(4):503-4, 2013 Mar.

31. Level V
‘’Level V lymphadenectomy may be omitted in the treatment of PTC patients if positive nodes are not found on histologic exam (frozen section analysis) or by ultrasonography in level IV’’
‘’Not all patients with PTC required dissection of level I and V, decreasing the overall surgical complication rate‘’
Occult lymph node metastases in neck level V in papillary thyroid carcinoma. Lim YC et al. Surgery Feb
Retrospective review on LND, 15 percent had level 5 met compare with ( 2:49, 3:74, 4:69)
Isolated level V met Is not found
All level V met had simultaneously level IV met
Retrospective study by Orlo Clark group conclude that not all patient require…
Selective modified radical neck dissection for papillary thyroid cancer: is level I, II and V dissection always necessary?
Caron NR, et al. World J Surg 2006

32. Va/ Vb
‘…the upper posterior triangle (Level Va) is less likely to harbor occult tumor’
How about the subdivision of level V as CN11 is lied in level Va
Ppl start to question of rate of met of Va, which can be avoid the nerve injury if not dissect
Retrospective review again
+ nodes on Vb is 31percent but Va is 8 percent
Management of lateral cervical metastases in papillary thyroid cancer: patterns of lymph node distribution.
King, J Michael et al. Ear, Nose & Throat Journal, Aug 2011

33. Va/ Vb
‘’…. a selective neck dissection of levels IIa, III, IV and Vb in N0 neck PTC is sufficient for clearance of occult metastases’’
This is another retrospective study on the pattern of LN met for patient undergoing prophylactic LND from 2 to 5 for PTC
They found that level Vb was affected in 5.7 percent while no cases involve in Va
They conclude that…..
Pattern of lateral neck metastases in N0 papillary thyroid carcinoma. Vincent Patron et al.
BMC cancer 2011

34. Morbidity of lateral neck dissection

35. Morbidity Chyle leakage Spinal assessory nerve damage
Carotid artery rupture
Nerve injury

36. International guidelines

37. International guidelines
NCCN guideline 2013
If LNs are palpable or positive on biopsy, then central neck dissection (Level VI) and lateral neck dissection (at least levels II-IV and Vb) are recommended
If the nodes are negative, prophylactic neck dissection (Level VI) can be considered but is not required in all cases (Category 2B recommendation)
ATA guideline 2009
Therapeutic lateral neck compartmental lymph node dissection should be performed for patients with biopsy proven metastatic lateral cervical lymphadenopathy (Recommendation rating: B)
BTA guideline 2007
When suspicious/clinically involved nodes are apparent pre-operatively or are encountered at surgery in the lateral neck, and confirmed by needle biopsy or frozen section, then a selective neck dissection (levels IIa–Vb) is recommended, preserving the accessory nerve, sternocleidomastoid muscle and internal jugular vein’’ (IV, C)
Low level evidence (2B)
In NCCN guideline the recommendation of a therapeutic LND include 2 to 5a, and they dun recommend prophylactic
But in fact the recommendation is only level 2b which is only by a low level evidence
In ATA and BTA guideline they dun recommend prophylactic dissection. Again, only a very vague low level eveidence of recommendation showed
It showed that there is no consensus and no high level of evidence on this topic. And it should be mx case by case in

38. Conclusion Skip metastasis may occur in PTC
Prophylactic LND is controversial
Therapeutic LND includes Level II to V as gold standard
It’s important to strike a balance between oncological benefit and surgical risk in the extent of selective neck dissection

39. The End
Staging
Sentinal LN