Prospective Study to Assess the Anatomical Relationship of Level IB Lymph Nodes to the Submandibular Gland in Patients With Carcinoma of the Upper Aerodigestive Tract

Hypothesis

1. The submandibular gland is not a lymphatic organ and usually remains uninvolved with head and neck cancer despite the presence of metastatic disease in the lymph nodes that surround it.
2. All the lymph nodes in the submandibular triangle can be removed without resection of the submandibular gland.

Study Design

1. A prospective controlled study.
2. A neck dissection of at least the ipsilateral sub-level 1B will be performed in all patients. In case of oral cavity tumors, about 15 minutes prior to the surgery, 1ml of Lymphazurin® blue dye will be injected in 4 quadrants around the primary site. The dissection will be performed in 3 stages. In the first stage all lymph node groups that lie either lateral, anterior, posterior, superior, or inferior to the submandibular gland, but within anatomical boundaries of level 1B, will be dissected. The submandibular gland will be left intact for this portion of the procedure. Next, the submandibular gland will be removed. Lastly, any remaining fibrofatty tissue that lies deep to the submandibular gland within the confines of level IB will be removed. Each lymph node group, the submandibular gland, and the fibrofatty tissue lying deep to the submandibular gland, will be submitted for pathological assessment in separate containers.
3. The following end-points will be measured: the number of lymph nodes identified within each lymph node group, the number of lymph nodes located within the submandibular gland, and the number of lymph nodes within the fibrofatty contents lying deep to the submandibular gland. The presence or absence of carcinoma within each of the assessed nodes will be documented, as well as extracapsular spread.

A better understanding of the frequency of submandibular gland involvement may lead to refined treatment strategies for head and neck cancer, which can possibly spare removal of the submandibular gland and potentially improve the long term side effects from therapy.