8-A837A-2017-Books-00129-029-060_Katz_Sec1_Ch02-ROUND-1

C H A P T E R 2 | Oncologic Components of Lymphadenectomy

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thyroglobulin levels and lower RAI uptake; 147 (2) improved cancer staging, which can then allow for proper use of RAI ablation/treatment; 145,148–152 and (3) a decrease in lo- coregional recurrence and improved disease-free survival rates. 142,151,153 Other studies have reported no improvement in patient outcomes and an increased use of postoper- ative RAI, as well as increased morbidity for patients who undergo pCCND. 140,154–157 The incidence of temporary hypocalcemia is reported to be significantly higher in patients who have undergone pCCND, although there is no difference in the risk of permanent hypoparathyroidism or RLN injury when the procedure is performed at specialized centers. 137,158 METHODOLOGY Relevant reports in English published between January 1990 and March 2016 and included in the PubMed database were reviewed. Randomized trials were preferred; however, when this type of data was not available, retrospective institutional stud- ies with a minimum of 100 patients and cohort studies were used. Search terms included central neck, prophylactic, routine, elective, lymph node, dissection, lymphadenectomy, papillary thyroid cancer, local recurrence, locoregional recur- rence, regional recurrence, hypoparathyroidism, recurrent laryngeal nerve, and survival. Previously published guidelines and consensus statements from the American Thy- roid Association, 42 the National Cancer Center Network, 37 and the European Society of Endocrine Surgeons 159 were also reviewed. Five published meta-analyses on the subject were reviewed. A search of references from meta-analyses and expert reviews on the topic was also performed by hand (Fig. 2-13). Articles that included patients who underwent therapeutic CCND or lateral com- partment neck dissection were excluded, as were articles focused on patients with pap- illary thyroid microcarcinoma or that included patients with benign thyroid disease. Fifteen studies were included that were relevant to the key question and met inclusion criteria. Only one prospective, randomized controlled study comparing total thyroidec- tomy and bilateral pCCND to total thyroidectomy without pCCND was identified. 140 The remaining studies were nonrandomized, retrospective studies with . 100 patients who had preoperative imaging to assess the central compartment and postoperative follow-up with reasonable assessment of local recurrence (cervical ultrasonography, serum thyroglobulin levels, and results of RAI) (Table 2-1). 137,142,147,150,151,154,160–165 Also of interest were meta-analyses of such studies (Table 2-2). 137,157,158 FINDINGS It may be difficult to demonstrate that pCCND and removal of cN0 disease ultimately will lead to a decrease in locoregional recurrence rates. A study evaluating the feasi- bility of performing a prospective, randomized controlled trial to evaluate the use of pCCND in patients with PTC found that the sample size required for adequate statis- tical power would be prohibitive. With this in mind, the only prospective, randomized controlled trial evaluating pCCND in patients with PTC is a single-institution report by Viola et al. 140 In their power calculation, the authors used a noninferiority margin