Table 1. Results of the studies showing the incidences of lymph nodes metastasis at level IIa and IIb in patients with TPC.
| Authors [years] | Total patients [ND] | Metastasis rates (%) |
Comment | |
|---|---|---|---|---|
| IIa | IIb | |||
| Pingpank et al. (40) [2002] | 44 [51] | 43.1 | 20.6 | Level IIb metastasis is common |
| Lee et al. (30) [2007] | 46 [55] | 58.2 | 21.8 | Level IIb dissection should be performed if level IIa LNM is found |
| Roh et al. (9) [2008] | 52 [57] | 72.7 | 16.7 | Level IIb metastasis always accompanied by level IIa metastasis |
| Lee et al. (29) [2008] | 167 [191] | 55.5 | 6.8 | Level IIb dissection is not necessary if level IIa LNM is negative |
| Yanir et al. (34) [2008] | 27 [28] | 50.0 | 7.1 | Level II-VI dissection should be performed in clinically +N |
| Farrag et al. (41) [2009] | 53 [60] | 56.0 | 8.5 | Level IIb dissection should be performed if level IIa LNM is found |
| Koo et al. (31) [2009] | 76 [76] | 51.3 | 11.8 | Level IIb dissection may be omitted in multilevel involvement including level IIa (-) |
| Vayisoglu et al. (39) [2010] | 33 [47] | 12.7 | 2.1 | Level IIb dissection may be required if multilevel metastasis or intraoperatively (+) LN |
| King et al. (42) [2011] | 32 [39] | 48.7 | 61.5 | Level IIb metastasis is common |
| Kim et al. (43) [2012] | 18 [18] | 46.7 | 20.0 | Level IIb dissection should be considered |
Abbrevation: TPC, thyroid papillary carcinoma; LMN, lymph node metastasis.