omohyoid, submandibular gland, IJV and XI were possible with similar survival rates but he also noted the importance of leaving structures to protect the carotid artery. Bocca and Pignataro later described the functional neck dissection (FND) in which the IJV, SCM and XI are preserved if possible. Bocca later established the oncologic safety of the FND when compared to the RND in 1975. The functional neck dissection is the same as the modified radical neck dissection (MRND).
Management of the N0 neck has been debated since the 19th century. In 1885, Butlin questioned radical neck dissection for N0 disease. Solis-Cohen recommended lymphadenectomy in N0 patients with laryngeal carcinomas in 1901. Until the late 20th century, RND was the primary surgical therapy for nodal mets. With the advent of the FND, the frequency of RND has decreased but still remains the gold standard to which all other therapies are compared to. In the 1960’s, MD Anderson physicians began to advocate selective removal of high risk nodal basins depending on the primary tumor site. In the last thirty years, the trend towards more conservative surgical therapy has been accompanied by improved efficacy of radiation therapy. Currently, surgical therapy for clinically positive nodal metastases will consist of a modified radical neck dissection or radical neck dissection depending on the involvement of tumor with any non-lymphatic structures. In general selective neck dissections are performed more as staging procedures for patients with N0 disease.
Since cervical anatomy is complex, there are many ways to divide the neck into different triangles and zones. The lymphatics in the head and neck are extensive and there can be up to 300 lymph nodes in specimens depending on the patient’s age. A more detailed description of pertinent cervical anatomy can be found in prior ground rounds. Evaluation of nodal drainage patterns and primary tumor locations by the Sloan-Kettering Memorial Group has helped standardize the nomenclature in regard to cervical nodal basins. The cervical nodes are divided into six groups which have been further divided into subgroups. A brief outline of the boundaries and regions which drain primarily into each level follows:
Submental and submandibular nodes Level Ia*: Submental triangle
Boundaries o Anterior bellies of the digastric muscle
o Hyoid bone Primary drainage o Chin o Lower lip o Anterior floor of mouth o Mandibular incisors o Tip of tongue Level Ib*: Submandibular triangle
o Body of the mandible o Anterior and posterior belly of the digastric muscle Primary drainage