What Lymph Node Levels does a Lateral [Therapeutic] Neck Dissection for Differentiated Thyroid Cancer (DTC) Include?

  • What lymph node levels does a lateral [comprehensive / therapeutic] neck dissection for differentiated thyroid cancer (DTC) include?
  • Although the rate of clinical nodal involvement in the lateral compartment was initially described by Japanese (Noguchi et al. 1970) and Germans (Gimm et al. 1998):
    • Sivanandan et al (2001) were the first to systematize it by levels
  • In 2013, the Canadian group of Jeremy L. Freeman (Eskander et al. Thyroid) conducted a systematic review that included the meta-analysis of 18 publications (including his 2012 retrospective work with 185 patients; Merdad et al. Head Neck) agglutinating 1298 lateral neck dissections for DTC:
    • Although heterogeneity was a constant in all comparisons by levels (I2: 31% to 87%), it is the best evidence to date that justifies the use of selective emptying IIa-Vb in this cohort of patients with this pathology:
      • Level III is the most frequently compromised
      • The majority (73%) of patients have more than one level involved:
        • Level III and IV:
          • 46%
        • Level II, III and IV:
          • 26%
        • Level III, IV and V:
          • 11%
        • Level II, III, IV and V:
          • 13% (Merdad et al. 2012)
  • Levels I and sublevel Va (cranial to the distal spinal nerve pathway):
  • Are rarely involved, usually in patients with high disease volume and multilevel invasion
  • Emptying of sublevel IIb (retrospinal recess):
    • Is usually indicated when clinical, radiological or macroscopic involvement is evident intraoperatively
    • The macroscopic involvement evident in the intraoperative sublevel IIa usually determines the addition of sublevel IIb to the neck dissection
  • “Skip metastases” within the lateral compartment are uncommon and occur in around 9% of patients:
    • Level II with level III and IV
    • Level V with level III and IV
      • (Merdad et al. 2012)
  • Selective lymphadenectomy IIa to Vb currently dissects levels IIa, III, IV, Vb and the “infraspinal” portion of the VA [VAi] in order to avoid the functional sequelae of cranial nerve XI dissection

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