 However it is based on the 2002 American Academy system, although the boundaries are defined slightly differently.The boundaries are defined as (Superior, Inferior, Antero-medial, Postero-lateral)

While an imaging based system was proposed in 1999, these concepts were integrated into the 2002 revision of the American Academy system.In addition to needing a standardised approach to classification of lymph nodes for the purposes of neck dissection, the application of radiation therapy also requires such an approach and has resulted in an international consensus guideline (2013).