**2.1 Classification and types of neck dissection**

The management of nodal metastasis must be discussed with clear definitions of various types of lymph node involvement:


In cN+ patients, lymphadenectomy is referred to as therapeutic neck dissection. Whereas in cN0 patients, lymphadenectomy is referred to as prophylactic neck dissection. The distinction between prophylactic and therapeutic neck dissection cannot be overemphasized as the impact of clinically detectible macroscopic nodal involvement is different from microscopic metastasis in cN0-pN+ disease.

Neck dissection is also classified by the lymphadenectomy extent (**Table 3**) [13]. Selective neck dissection is increasingly performed as the growing knowledge of the pattern of spread of various cancers enables surgeons to spare the lymph node levels not considered at risk of nodal metastasis. Selective neck dissection has been traditionally further classified into supraomohyoid neck dissection (level I–III), central neck dissection (level VI), lateral neck dissection (level II–IV), and posterolateral neck dissection (level II–V). However, these selective neck dissection terminologies were confusing and obsolete with variable inclusion or exclusion of certain levels and sublevels. Hence, selective neck dissection is better described by specifying the levels and sublevels included [13].

