In turn, this information in conjunction with histologic type serves to define treatment approach and management. The appropriate imaging technique is generally determined by the site Assessment of Head and Neck Cancer of origin [108]. Fine-needle aspiration remains the most definitive tool to determine the benign or malignant nature of salivary gland masses [106]. US, cross-sectional imaging (CT, MRI), and functional imaging with FDG-PET/CT may be used independently or in combination to enhance the diagnostic strength and reduce the deficiency of each modality [106]. Furthermore, imaging characteristics are particularly helpful when fine-needle aspiration cannot be performed because of inaccessible location or patient preference. In established malignancy, staging to include nodal disease and distant metastases may be warranted. Locoregional metastatic adenopathy is seen in approximately 10% to 15% of malignant salivary gland tumors and is more common in high-grade than in low- grade cancer [108]. Distant metastatic disease is identified in 10% to 50% of patients at initial staging, and both lymph node and distant metastases are more common in the setting of tumor recurrence [108]. Perineural tumor spread is especially prevalent in adenoid cystic carcinoma and is reported in >50% of patients [108]. Radiography Chest CXR is not considered useful in the evaluation of pulmonary metastatic disease in the initial staging of suspected or diagnosed cancer of a major salivary gland. Chest CT is far more sensitive in detecting pulmonary metastatic disease compared to radiography [15], with the sensitivity of CXR to detect pulmonary metastatic disease reported as low as 28% compared to chest CT [11]. The low sensitivity may in part be due to the small size of pulmonary nodules at presentation or peripheral location, in which CXR tends to be less reliable [11].
Staging and Post Therapy Assessment of Head and Neck Cancer. In turn, this information in conjunction with histologic type serves to define treatment approach and management. The appropriate imaging technique is generally determined by the site Assessment of Head and Neck Cancer of origin [108]. Fine-needle aspiration remains the most definitive tool to determine the benign or malignant nature of salivary gland masses [106]. US, cross-sectional imaging (CT, MRI), and functional imaging with FDG-PET/CT may be used independently or in combination to enhance the diagnostic strength and reduce the deficiency of each modality [106]. Furthermore, imaging characteristics are particularly helpful when fine-needle aspiration cannot be performed because of inaccessible location or patient preference. In established malignancy, staging to include nodal disease and distant metastases may be warranted. Locoregional metastatic adenopathy is seen in approximately 10% to 15% of malignant salivary gland tumors and is more common in high-grade than in low- grade cancer [108]. Distant metastatic disease is identified in 10% to 50% of patients at initial staging, and both lymph node and distant metastases are more common in the setting of tumor recurrence [108]. Perineural tumor spread is especially prevalent in adenoid cystic carcinoma and is reported in >50% of patients [108]. Radiography Chest CXR is not considered useful in the evaluation of pulmonary metastatic disease in the initial staging of suspected or diagnosed cancer of a major salivary gland. Chest CT is far more sensitive in detecting pulmonary metastatic disease compared to radiography [15], with the sensitivity of CXR to detect pulmonary metastatic disease reported as low as 28% compared to chest CT [11]. The low sensitivity may in part be due to the small size of pulmonary nodules at presentation or peripheral location, in which CXR tends to be less reliable [11].