The lungs are the most frequent site for distant metastatic disease, and when other sites of distant metastatic disease are present, pulmonary nodules are almost always present [11,14]. Skeletal metastases, most frequently of ribs and vertebrae, confers morbidity, including pain and symptoms of hypercalcemia [11]. Detection of distant metastatic disease at initial staging is crucial because it will change prognosis and typically change the management strategy toward more systemic options. An increased rate of second primary malignancy and concurrent lung malignancy among head and neck cancer patients has been linked to the intake of tobacco and alcohol [15,16]. Cancer of unknown primary of the head and neck represents 1% to 4% of patients with malignant tumors of the head and neck and is diagnosed after identification of metastatic cervical lymphadenopathy in which no primary is evident [9]. When the pathology is consistent with HPV-related squamous cell carcinoma, the primary site is presumed to localize to the oropharynx. Initial staging should include every attempt at identifying the site of primary because this impacts prognosis and treatment planning, and it is important to document the extent of nodal disease in the neck. Despite multimodality imaging and endoscopic evaluation, 2% to 9% of primary sites remain undetected [17]. Radiography Chest Chest radiography (CXR) is not useful for the evaluation of pulmonary metastatic disease in the initial staging of suspected or diagnosed cancer of the oral cavity or oropharynx or hypopharynx or larynx or cancer of unknown primary of the head and neck. Chest CT is far more sensitive in detecting pulmonary metastatic disease when compared to radiography [15], with the sensitivity of CXR to detect pulmonary metastatic disease reported as low as 28% when compared to chest CT [11].
Staging and Post Therapy Assessment of Head and Neck Cancer. The lungs are the most frequent site for distant metastatic disease, and when other sites of distant metastatic disease are present, pulmonary nodules are almost always present [11,14]. Skeletal metastases, most frequently of ribs and vertebrae, confers morbidity, including pain and symptoms of hypercalcemia [11]. Detection of distant metastatic disease at initial staging is crucial because it will change prognosis and typically change the management strategy toward more systemic options. An increased rate of second primary malignancy and concurrent lung malignancy among head and neck cancer patients has been linked to the intake of tobacco and alcohol [15,16]. Cancer of unknown primary of the head and neck represents 1% to 4% of patients with malignant tumors of the head and neck and is diagnosed after identification of metastatic cervical lymphadenopathy in which no primary is evident [9]. When the pathology is consistent with HPV-related squamous cell carcinoma, the primary site is presumed to localize to the oropharynx. Initial staging should include every attempt at identifying the site of primary because this impacts prognosis and treatment planning, and it is important to document the extent of nodal disease in the neck. Despite multimodality imaging and endoscopic evaluation, 2% to 9% of primary sites remain undetected [17]. Radiography Chest Chest radiography (CXR) is not useful for the evaluation of pulmonary metastatic disease in the initial staging of suspected or diagnosed cancer of the oral cavity or oropharynx or hypopharynx or larynx or cancer of unknown primary of the head and neck. Chest CT is far more sensitive in detecting pulmonary metastatic disease when compared to radiography [15], with the sensitivity of CXR to detect pulmonary metastatic disease reported as low as 28% when compared to chest CT [11].