الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 87 |  |  |
| | | from | 87 | | |
Abstract
Head and neck cancers (HNC) are dominated by squamous cell carcinomas originated from the epithelium of the upper aerodiagestive tract.with a frequently aggressive behaviour and a strong correlation with tobacco use. Cervical lymph node metastasis, reported as the most important mechanism of spread, is one of the most critical prognostic factors for staging tumors and deciding upon a management strategy. Diagnosis of cervical metastases may be effectuated by a number of methods, with histopathological examination of a head and neck dissection specimen considered the gold standard. Clinical assessment by palpation is the most widely used method for detecting cervical metastases; however, both sensitivity and specificity of this method are low.
The management of cervical metastatic disease has, historically, been a controversial topic, more so in the case of the clinically N0 neck. It is a recognized fact that cervical metastases is the most important prognostic factor in HNSCC, showing a 50 % reduction in five year survival rates for ipsilateral nodal metastases, and a 75 % reduction in case of bilateral metastases. Thus the evaluation of the neck nodes for metastases is paramount in the management of cases of HNSCC.
Management of cases with clinically positive node is straight forward, treatment being radical/modified radical neck dissection. Management of clinically node-negative cases is controversial, options being observation, radiation or surgery. Elective neck dissection improved overall survival and reduced risk of death when compared with observation for node-negative, squamous cell carcinoma of the oral cavity .These findings made strong evidence to decide treatment for N0 neck. A
staging supraomohyoid neck dissection (SOND) is recommended for all patients with T2 disease at the primary site and possibly in T1 disease with greater than 4 mm depth of invasion. SLNB (sentinel lymph node biopsy) in the management of the cN0 neck is introduced to lessen the morbidity associated with neck dissection, while still providing proper staging of the neck. SLN is the first node among all nodes in drainage area where metastasis spread first. So, if SLN is negative for malignancy, assumption is that the rest of the nodal area is free of tumour.
Currently, despite improvements in imaging using ultrasound, CT, MRI, and PET scanning, SLNB is the only investigation that can detect micrometastatic disease.
Some authors have suggested that patients with negative results using the most accurate imaging studies, such as CT or PET-CT, could be candidates to a wait-and-see policy.
The need for a better diagnostic technique to identify subclinical cervical metastases and guide the treatment of these patients ultimately has lead to the development of SLN biopsy.