Central and lateral neck dissection for differentiated thyroid cancer Diferansiye tiroid kanserlerinde santral ve lateral boyun diseksiyonu tekniği

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2 Central and lateral neck dissection for differentiated thyroid cancer Diferansiye tiroid kanserlerinde santral ve lateral boyun diseksiyonu tekniği Leigh Delbridge President, International Association of Endocrine Surgeons Professor and Head of Surgery, The University of Sydney 25 th April 17:20 (40 minutes)

3 paradigm shift there has been a paradigm shift in the management of differentiated thyroid cancer over the last decade, specifically related to the management of lymph nodes in papillary thyroid cancer delayed recognition that the long standing Asian approach of routine cervical lymph node dissection impacts outcomes papillary cancer is now primarily a surgical disease with relegation of the role of radioiodine ablation

4 Japanese approach 25 years ago routine neck dissection is the best treatment for patients >40 yrs with primary tumours 1.5 cm in size whether or not nodes are clinically palpable. With this recurrence free survival rate can be improved substantially Noguchi S, Murakami N. Surg Clin North Am 1987;67:251

5 Western approach 25 years ago prophylactic removal of regional lymph nodes, with or without metastases, does not improve cure rates there is an inverse relationship between lymph node metastases and survival rate in thyroid cancer such that the more frequent the number of nodal metastases, the better the prognosis Cady B. Arch Surg 1984;119:1067 everyone who works with papillary thyroid cancer knows that most of the patients have lymph node metastases. We also know that they do not have any bearing on outcome Cady B. World J Surg 1994;18:558

6 risk stratification development of various risk stratification systems to identify low risk vs high risk patients none of these systems incorporated involved lymph nodes AGES age grade extent size AMES age dist mets extent size DAMES age dist mets extent size diploid GAMES age grade dist mets extent size MACIS age dist mets (invas) size completeness

7 SCNA 2009 total thyroidectomy is now accepted as standard care clinically evident disease requires formal compartment oriented therapeutic lymph node dissection prophylactic central lymph node remains controversial but dissection should be considered for most patients with papillary thyroid cancer Suliburk J, Delbridge L. SCNA 2009; 89:1171

8 revised ATA guidelines AIM: to remove the tumor, disease that has extended beyond the capsule and involved cervical lymph nodes. WHY: completeness of resection is an important determinant of outcome whilst residual metastatic lymph nodes represent the most common site of recurrence/persistence Cooper DS, Doherty GM, Haugen BR et al. Thyroid 2009;19:

9 lecture outline NECK DISSECTION FOR PAPILLARY CANCER definitions: therapeutic vs prophylactic central vs lateral unilateral vs bilateral summary of evidence what is the best operation? surgical technique: video of steps

10 therapeutic vs prophylactic ATA/AAES consensus statement definitions a therapeutic neck dissection implies that nodal metastasis is apparent clinically (pre operatively or intra operatively) or by imaging a prophylactic neck dissection implies that nodal metastasis is not detected clinically or by imaging (clinically N0) Carty SE, Cooper DS, Doherty GM et al. Consensus statement on the terminology and classification of central neck dissection for thyroid cancer. Thyroid 2009;19:1153

11 central vs lateral esophagus RLN innominate vein

12 what really is the central neck? numerous descriptions of the central compartment considerable variation in clinical practice from removal of just level VI paratracheal nodes through to removal of all tissue between both carotid arteries from hyoid to innominate vein

13 the four groups of lymph nodes in the central (level VI) compartment are: prelaryngeal (Delphian) nodes pretracheal lymph nodes the right and left paratracheal nodes including any retropharyngeal or retro oesophageal nodes. Carty SE, Cooper DS, Doherty GM et al. Thyroid 2009;19:1153

14 level VII retromanubrial nodes are simply the in continuity inferior extension of pretracheal nodes to the innominate vein and should logically be considered as part of the central compartment Sydney practice is to include Level VII

15 unilateral vs bilateral central neck dissection (CND) includes a comprehensive, compartment oriented removal of: 1. pre laryngeal nodes 2. pretracheal nodes 3. at least one paratracheal node basin. unilateral CND = removal of one paratracheal compartment on the side of the tumour bilateral CND = removal of both paratracheal compartments Carty SE, Cooper DS, Doherty GM et al. Thyroid 2009;19:1153

16 overview therapeutic lateral for clinically evident disease central for clinically evident disease prophylactic lateral defies the logic of prophylaxis central controversial area with need to balance risks and benefits

17 rationale of prophylactic surgery the rationale for prophylactic node dissection at the time of total thyroidectomy is that this provides the best opportunity to achieve safe nodal clearance. Re entering the central compartment for a therapeutic at a later stage poses increased risks of complications. Unnecessary for the majority of patients so risks must be minimal. absolutely no logic to prophylactic lateral node dissection, as there is no increased risk to undertaking therapeutic lateral node dissection, if required, as a secondary procedure only potential benefit is upstaging

18 the current major area of controversy therefore surrounds the relative risks versus the potential benefits of prophylactic central neck dissection for N0 patients primum, non nocere first, do no harm approach must be to balance risks and benefits

19 total thyroidectomy alone no prophylactic CND nodal persistence small operative risks

20 standard of care until recently reduces risk of local recurrence removes of multifocal disease allows radioiodine ablation facilitates follow up with Tg removes risk of de differentiation avoids risks of re operative surgery Sosa JA, Udelsman R. J Surg Oncol. 2006;94:701 7

21 total thyroidectomy alone regional nodes present in 20 to 90% of patients in many cases these nodes do not appear abnormal to inspection Tisell LE. World J Surg 1996;20:854 commmonest cause of local recurrence is in the central lymph node compartment in the tracheo esophageal groove

22 lymph nodes do impact survival Swedish population study (n=5,123) nested case control study matched for age, sex and calendar year patients with lymph node metastases were more likely to die (OR, 2.5; 95% CI, ) still significant after adjustment for TNM (OR, 1.9; 95% CI ) Lundgren CI, Hall P.. Zedenius J. Cancer 2006;106:524 31

23 typical case 42 female with PTC total thyroidectomy 4 doses of radioiodine over 6 years because of a persistently elevated serum Tg 15 yrs later local recurrence left central neck managed by selective Level VI node dissection now Tg negative for the first time ever

24 total Tx +prophylactic CND surgical equipoise clearance of local disease acceptable operative risks

25 why routine prophylactic metastases in this area are not reliably identified by preoperative high resolution ultrasound moreover they are not easily identified at operation by palpation as they often lie in the tracheoesophageal groove deep to the RLN Marshall CL, Lee JE, Xing Y, Perrier ND, Edeiken BS, Evans DB, et al. Surgery. 2009;146:1063

26 initial Sydney data retrospective cohort study total thyroidectomy alone vs total thyroidectomy plus prophylactic ipsilateral central lymph node dissection pre op node negative neck clinically and on routine ultrasound histologically proven PTC >1cm lateral lymph node involvement beyond level VI excluded Sywak M, Cornford L, Roach P, Stalberg P, Sidhu S, Delbridge L. Surgery. 2006;140:1000

27 post ablative serum TG levels Serum TG ug/l 6 12 months No of 131 I treatments * Stimulated TG levels 0.95 Group A TTx+LND 0.41 Group B TTx Group A Group B *P=0.02 P=0.51

28 study conclusion no difference in permanent complications routine prophylactic ipsilateral central lymph node dissection can be performed safely associated with significantly lower levels of stimulated thyroglobulin following 131 I ablation. results in higher rates of athyroglobulinemia when compared with total thyroidectomy alone Sywak M, Cornford L, Roach P, Stalberg P, Sidhu S, Delbridge L. Surgery. 2006;140:1000

29 Michigan data 143 patients with clinically node negative PTC no difference in stimulated serum thyroglobulin levels and the number of patients with undetectable stimulated thyroglobulin levels post op and at 1 year the presence of involved central neck lymph nodes upstaged 28.6% of patients questions the potential for any long term benefit of prophylactic central node dissection, namely reduced long term central compartment recurrence Hughes DT, White ML, Miller BS, Gauger PG, Burney RE, Doherty GM. Surgery. 2010;148:1100

30 Randolph editorial commentary prophylactic CND should not be performed no conclusive published data that prophylactic CND improves survival or local recurrence prophylactic CND frequently leads to microscopic pre clinical upstaging without evidence of therapeutic benefit only a small fraction of patients will ever require therapeutic CND if prophylactic CND is not performed the surgical skill is not readily available the presence of a surgical skill sufficient to perform a procedure is not an indication for the procedure Randolph GW. Surgery 2010;148:

31 Chernobyl data we believe prophylactic central compartment neck dissection was one of the major circumstances that decreased the chance of recurrence which in most instances (81.2% sites cumulatively) manifested as regional metastasis guideline based surgical treatment significantly reduced local recurrence (HR = 0.17, 95% CI = ) Rumyantsev PO, Saenko VA, Iilyn AA... Yamashita S. J Clin Endocrinol Metab 2011;96:

32 multicenter study A Multicenter Cohort Study of Total Thyroidectomy versus Total Thyroidectomy and Prophylactic Central Lymph Node Dissection University of Sydney Endocrine Surgical Unit Endocrine Surgical Unit, UCLA, California Dept Endocrine Surgery, Hammersmith Hospital 606 patients with papillary cancer > 1cm node negative on clinical and ultrasound 347 had prophylactic central node dissection 259 had total thyroidectomy only Popadich A...Delbridge L, Yeh M. Presented at AAES Annual Meeting, Texas, April 2011 (in press Surgery)

33 results 1 in the prophylactic CND group, 127 patients (49%) had nodal metastatic disease proven at final histology. ipsilateral CND was performed in 203 (78%) patients, and 56 (22%) had bilateral CND in the study population as a whole a total of 28 (5%) patients were upstaged according to the AJCC staging system for differentiated thyroid cancer.

34 results 2 in the group having prophylactic central node dissection: stimulated thyroglobulin levels were significantly lower prior to initial radio iodine ablation (15.0 versus 6.6ng/ml, p=0.025) the rate of re operative surgery in the central compartment was significantly lower (1.5 versus 6.1%, p=0.004). the calculated number of CND procedures required to prevent one central compartment re operation was 20.

35 complications No CND PCND temporary hypocalcemia 4.1% 9.7% (p=0.026) permanent hypoparathyroidsim 0.5% 0.4% temporary RLN neuropraxia 2.3% 0.4% permanent RLN palsy 1.8% 0.4% hematoma 0.9% 1.8% wound infection 1.4% 1.2% parathyroid glands autotransplanted (mean) (p=0.006)

36 multicenter study conclusion routine CND for cn0 PTC can be performed at the time of initial surgery with no apparent increase in long term morbidity. routine CND results in a lowering of the initial preablation stimulated serum thyroglobulin greatly facilitating long term follow up management routine CND in addition to total thyroidectomy is associated with a lower recurrence rates of PTC and a significant reduction in the need for re operation in the central compartment Popadich A...Delbridge L, Yeh M. Presented at AAES Annual Meeting, Texas, April 2011 (in press Surgery)

37 unilateral or bilateral CND? increased risk of permanent complications vs better clearance of involved nodes?

38 increased morbidity of bilateral CND 110 patients with PTC bilateral CND 77% had lymph node metastases 86% temporary hypocalcaemia 5% permanent hypoparathyroidism no CND 61% temporary hypocalcaemia no permanent hypoparathyroidism Rosenbaum MA, McHenry CR. Arch Otolaryngol Head Neck Surg 2009;135:1092

39 Mayo optimized surgical strategy 420 pts optimized up to 2006 near total thyroidectomy bilateral CND after routine ultrasound lateral dissection II/IV/VI + II if node +ve 5% developed LN recurrence in previously operated fields permanent hypoparathyroidism 1.2% and recurrent laryngeal nerve division 0.3% Grant CS, Stulak JM, Thompson GB, Richards ML, Reading CC, Hay ID. World J Surg. 2010;34:1239

40 for what benefit? 21 patients with bilateral node clearance vs 75 patients with unilateral level 6 clearance no effect on serum thyroglobulin levels temporary hypocalcemia 48% vs 20% the more conservative unilateral dissection is safer and as effective as bilateral clearance Lee YS, Kim SW... Chung KW. World J Surg 2007;31:1954

41 ? selective based on size routine bilateral CND with separate analysis of left and right basins tumor <1cm none had bilateral nodes tumour > 1cm 33% ipsilateral positive nodes 20% bilateral positive nodes favours bilateral CND for larger tumors Moo TA, Umunna B, Kato M et al. Ann Surg 2009;250:403

42 prophylactic central + lateral neck dissection extensive disease clearance significant morbidity post op

43 Gustave Roussy approach 115 pts routine prophylactic CND + LND for PTC < 2cm (negative cervical ultrasound) complications < 1% 97% had undetectable thyroglobulin levels Bonnet S, Hart D, Leboullex S et al. J Clin Endocrinol Metab 2009;94:1162 clear evidence of harm exceeding benefit for prophylactic central + lateral neck dissection Steward DL..in Mazzaferi EL et al. Thyroid 2009;19:683

44 Sydney surgical equipoise over 85% of patients will have low risk papillary thyroid cancer for the typical patient total thyroidectomy + prophylactic unilateral CND provides the best balance selective use of prophylactic bilateral CND clearance of local disease acceptable operative risks

45 central nodes 1 prelaryngeal (Delphian) nodes notch of thyroid cartilage to cricoid and top of isthmus remove pyramid and clear cricothyroid membrane

46 prelaryngeal nodes

47 central nodes 2 pretracheal nodes bottom of isthmus to sternal notch laterally to medial border of each thymus, clearing all tissue to tracheal surface

48 pretracheal nodes

49 central nodes 3 (level VII) retromanubrial nodes sternal notch to innominate vein simply the caudal continuation of the pretracheal dissection remaining medial to each thymus

50 retromanubrial nodes

51 central nodes 4 right paratracheal nodes follows RLN from inferior thyroid artery to common carotid continuous with paratracheal dissection removing thymus and tissue in tracheo esophageal groove

52 parathyroid autotransplantation the inferior parathyroid gland always lies within the operative field thyroid capsule thyrothymic tract if it is not found and transplanted it is lost

53 parathyroid autotransplantation

54 right paratracheal nodes

55 central nodes 5 left paratracheal nodes follows RLN from inferior thyroid artery to thoracic inlet continuous with paratracheal dissection removing thymus and tissue in tracheo esophageal groove

56 left paratracheal nodes

57 ? tailored procedure risk of complications can be minimized by tailored procedures based on size of tumor location of tumor New York study: tumor <1cm none had bilateral nodes tumour > 1cm 33% ipsilateral positive nodes 20% bilateral positive nodes Moo TA, Umunna B, Kato M et al. Ann Surg 2009;250:403

58 unilateral dissection eg small tumor, superior pole delphian, pretracheal +ipsilateral paratracheal

59 bilateral dissection eg large tumor, inferior pole or central delphian, pretracheal, bilateral paratracheal + retromanubrial

60 take home messages most patients have low risk papillary thyroid cancer and will do very well however lymph node involvement does impact survival clinically evident node, central or lateral disease requires therapeutic dissection for the typical patient total thyroidectomy + prophylactic unilateral central node dissection CND provides the best balance in reducing the risk of local recurrence selective use of prophylactic bilateral CND

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