title: Should Level V Be Routinely Dissected in N1b Papillary Thyroid Carcinoma?
abstract: For N1b papillary thyroid carcinoma (PTC) patients, modified radical neck dissection (MRND) encompassing levels II-V is generally recommended. However, routine level V dissection is controversial because of the low incidence of metastasis/recurrence in level V and the increased morbidities associated with level V dissection.
  
  
  
  This study retrospectively reviewed 646 N1b PTC patients who underwent unilateral MRND between January 1997 and June 2015. Specifically, to assess surgery-related outcomes of level V dissection, outcomes from N1b PTC patients who underwent unilateral MRND (levels II-V) were compared with those who underwent unilateral selective neck dissection (SND; levels II-IV) using propensity score matching.
  
  
  
  Overall and occult level V metastases were observed in 13.9% and 8.6% of patients, respectively. Level V recurrences were observed in only 2.26 (7.7%) recurred N1b PTC patients who underwent unilateral MRND. In multivariate analysis, three-level (II, III, and IV) simultaneous metastasis (adjusted odds ratio = 3.079, p = 0.003) was an independent predictor for level V metastasis. Under a matched condition, "shoulder syndrome" encompassing shoulder dysfunction and pain (9.1% vs. 2.7%, p = 0.002) was significantly more frequent in the MRND group than it was in the SND group.
  
  
  
  Because of the low incidence of metastasis/recurrence in level V and the clear evidence of increased morbidities, level V dissection in N1b PTC patients may be reserved for those with three-level simultaneous metastasis or clinically/radiologically evident level V metastasis.
authors.affiliation: 1 Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul, South Korea .
authors.forename: Seo Ki
authors.initials: SK
authors.lastname: Kim
authors.affiliation: 1 Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul, South Korea .
authors.forename: Inhye
authors.initials: I
authors.lastname: Park
authors.affiliation: 1 Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul, South Korea .
authors.forename: Nayoon
authors.initials: N
authors.lastname: Hur
authors.affiliation: 2 Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine , Changwon, South Korea .
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: 1 Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul, South Korea .
authors.forename: Jun-Ho
authors.initials: JH
authors.lastname: Choe
authors.affiliation: 1 Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul, South Korea .
authors.forename: Jung-Han
authors.initials: JH
authors.lastname: Kim
authors.affiliation: 1 Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul, South Korea .
authors.forename: Jee Soo
authors.initials: JS
authors.lastname: Kim
mesh_terms: D000328:Adult; D002291:Carcinoma, Papillary / Q000473:pathology / Q000601:surgery*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection / Q000379:methods*; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D009367:Neoplasm Staging; D016017:Odds Ratio; D011183:Postoperative Complications / Q000453:epidemiology*; D012189:Retrospective Studies; D020069:Shoulder Pain / Q000453:epidemiology*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000473:pathology / Q000601:surgery*; D013965:Thyroidectomy / Q000379:methods
keywords: lateral lymph node metastasis; level V dissection; level V metastasis; modified radical neck dissection; papillary thyroid carcinoma