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

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TABLE 2-2 Locoregional Recurrence Rate (Central or Lateral Compartment) from Meta-analyses

Locoregional Recurrence (%)

No. of Patients

Meta-analysis

TT 1 pCCND TT

TT 1 pCCND TT

Difference in LRR

Zetoune et al, 157 2010

161

713

5.6

5.5

NS

Wang et al, 158 2013

745

995

4.7

7.9

NS

Lang et al, 137 2013

1,592

1,739

4.7

8.6

SS

Total

2,498

3,447

5.0*

7.3*

—

TT, total thyroidectomy; CCND, central compartment neck dissection; pCCND, prophylactic CCND; LRR, locoregional recurrence; NS, not significant; SS, statistically significant. *Mean.

of 15%, an expected ablation success and clinical remission rate of 85%, and a power of 90%. Adequate power required 98 patients per treatment group. The study enrolled 181 consecutive patients with PTC. All patients received total thyroidectomy (TT) and were randomly assigned to undergo bilateral pCCND (TT 1 bpCCND) or not (TT). Inclusion criteria were (1) PTC documented by FNA, (2) no evidence of lymph node metastases (cN0) at cervical ultrasonography or physical examination, (3) no clinical evidence of distant metastases at diagnosis, and (4) age of at least 18 years. Patients with lymph node metastases identified during thyroidectomy were excluded. Primary end points were the successful ablation rate and the incidence of persistent or recurrent disease after 5 years of follow-up. The secondary end points were the rate of surgical complications in the two groups and the effect of bilateral pCCND on the staging of PTC. The mean tumor size was 1.6 cm for both groups, and the median follow-up was 60 months (range, 41 to 71 months). Of the 93 patients who under- went TT 1 bpCCND, 43 (46%) had occult lymph node metastases (pN1a). Among 88 patients who underwent TT alone, six (6.8%) had lymph node metastases inci- dentally removed in the perithyroidal soft tissue. The rate of biochemical or persistent structural disease was 7.5% (TT 1 bpCCND) and 8% (TT) ( P 5 0.9). Patients were considered disease-free when, after recombinant thyroid-stimulating hormone admin- istration, serum thyroglobulin levels were , 1 ng/mL, a study by cervical ultrasound was normal, and thyroglobulin antibodies were undetectable. In those without RAI ablation, disease-free status was defined as a cervical ultrasound study with normal findings and undetectable/stable levels of serum thyroglobulin and thyroglobulin an- tibodies. However, significantly more patients with TT alone (17.4% vs. 3.4%, P 5 0.002) required more than one course of RAI. With respect to postoperative com- plications, a significantly higher prevalence of permanent hypoparathyroidism was observed in the TT than in the TT 1 bpCCND group (19.4% vs 8%, P 5 0.02). As a whole, the authors concluded that there were no clinical advantages in performing bilateral pCCND in patients with cN0 preoperatively.