Lateral neck dissection for papillary thyroid cancerJoint hospital Surgical Grand Round19 October 2013Dr. Dennis CT LamUnited Christian Hospital

Outline

Introduction Lateral neck dissection (LND) for PTC Indication of LND Extent of LND Morbidity of LND Conclusion

Introduction

Papillary thyroid cancer (PTC) composed of 77-85% of thyroid malignancies

Strong propensity for regional LN involvement

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.

Anatomy of Cervical Lymphatic

American Thyroid Association Guidelines Taskforce on Thyroid Nodules and Differentiated Thyroid Cancer

LND in PTC

Papillary thyroid cancer (PTC)

Lateral neck dissection (LND)

To dissect/ not to dissect

Extent of dissection

Patterns of Nodal Metastases

Central compartment

Lateral compartment

Contralateral neck

• Pattern of lymph node metastases in papillary thyroid carcinoma.

Gimm O, et al. Br J Surg 1998.

Usual scenario

Lateral compartment +ve

Central compartment +ve

Tumor in middle and lower poles

• Lymph node dissection in the lateral neck for completion in central node-positive papillary thyroid cancer.

Machens A, et al. Surgery 2009.

Concept of skip metastasis

Lateral compartment +ve

Central compartment –ve

Tumor in upper pole

• Skip lateral neck node metastases in papillary thyroid carcinoma. Park JH, et al. World J Surg 2012.

Patterns of Nodal Metastases

7%-19% skip metastasis

• Central cervical nodal metastasis from papillary thyroid microcarcinoma: pattern and factors predictive of nodal metastasis. Roh JL, et al. Ann Surg Oncol 2008.

Detection and Diagnosis

Physical examination Ultrasonography FNA cytology

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

To dissect/ not to dissect?

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

Prophylactic dissection

Primary tumor located in the upper pole Extensive involvement of the ipsilateral

central compartment

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.

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

Surgical management of cervical lymph nodes in differentiated thyroid cancerDanielle Fritze, et al. Otolaryngol Clin N Am 2010.

Extent of lateral neck dissection

Extent of lateral neck dissection

Selective ‘berry picking’ is associated with higher rates of loco-regional recurrence and has been largely abandoned

Greater local recurrence occurs with ‘berry picking’ than neck dissection in thyroid cancer. Musacchio MJ, et al. Am Surg 2003; 69:191–196.

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

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.

Most lateral compartment dissections routinely encompass levels II–V

Patterns of lateral neck metastasis in papillary thyroid carcinoma. Kupferman ME, et al. Arch Otolaryngol Head Neck Surg 2004

• 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.

Level IIa, III, IV

Levels IIa, III, and VI were each involved in more than 70% of patients

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.

Cervical lateral neck metastases in PTC occur in a predictable pattern, with levels III, IIa, and IV 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.

Level II

Level IIb

Only 16.7% of patients had positive nodes at level IIb

Involvement was associated with multilevel disease in all cases

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.

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’’

Level IIb lymph node metastasis in thyroid papillary carcinoma. Vayisoglu Y, et al. European Archives of Oto-Rhino-Laryngology 2010.

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’’

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.

Level V

Level V

‘’Level V lymphadenectomy may be considered in patients with lymph node metastasis in the ipsilateral lateral neck with macroscopic extranodal extension’’

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.

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. 2010 Feb

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

Va/ Vb

‘…the upper posterior triangle (Level Va) is less likely to harbor occult tumor’

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

Va/ Vb

‘’…. a selective neck dissection of levels IIa, III, IV and Vb in N0 neck PTC is sufficient for clearance of occult metastases’’

Pattern of lateral neck metastases in N0 papillary thyroid carcinoma. Vincent Patron et al. BMC cancer 2011

Morbidity of lateral neck dissection

Morbidity

Chyle leakage Spinal assessory nerve damage Carotid artery rupture Nerve injury

International guidelines

International guidelinesNCCN 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)

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

The End