 Introduction/Background Head and neck cancer comprises a heterogeneous group of malignancies that together represents the seventh most common cancer worldwide and ninth most common cancer in the United States [1]. Several anatomic sites are encompassed, including the oral cavity, oropharynx, hypopharynx, larynx, nasopharynx, paranasal sinuses, nasal cavity, and salivary glands. There is heterogeneity in histopathology; although, the majority of the cancers are squamous cell carcinomas. Head and neck cancers are clearly associated with alcohol and tobacco consumption, with human papillomavirus (HPV) and Epstein-Barr virus (EBV) linked to oropharynx cancer and nasopharynx cancer, respectively [2]. Special Imaging Considerations For the purposes of distinguishing between CT and CT angiography (CTA), ACR Appropriateness Criteria topics use the definition in the ACR-NASCI-SIR-SPR Practice Parameter for the Performance and Interpretation of Body Computed Tomography Angiography (CTA) [7]: Reprint requests to: publications@acr.org Assessment of Head and Neck Cancer All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with IV contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. PET/CT imaging of head and neck cancers is frequently extended beyond the skull-base to the vertex to ensure inclusion of the entirety of the tumor. Squamous cell carcinoma of the head and neck preferentially spreads to regional lymph nodes, with nodal disease conferring decreased survival rates. Presence of distant metastatic disease at the time of diagnosis has been reported in 10% to 18% of patients [10], and its occurrence is directly linked to the stage of tumor [11-13].
Staging and Post Therapy Assessment of Head and Neck Cancer.  Introduction/Background Head and neck cancer comprises a heterogeneous group of malignancies that together represents the seventh most common cancer worldwide and ninth most common cancer in the United States [1]. Several anatomic sites are encompassed, including the oral cavity, oropharynx, hypopharynx, larynx, nasopharynx, paranasal sinuses, nasal cavity, and salivary glands. There is heterogeneity in histopathology; although, the majority of the cancers are squamous cell carcinomas. Head and neck cancers are clearly associated with alcohol and tobacco consumption, with human papillomavirus (HPV) and Epstein-Barr virus (EBV) linked to oropharynx cancer and nasopharynx cancer, respectively [2]. Special Imaging Considerations For the purposes of distinguishing between CT and CT angiography (CTA), ACR Appropriateness Criteria topics use the definition in the ACR-NASCI-SIR-SPR Practice Parameter for the Performance and Interpretation of Body Computed Tomography Angiography (CTA) [7]: Reprint requests to: publications@acr.org Assessment of Head and Neck Cancer All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with IV contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. PET/CT imaging of head and neck cancers is frequently extended beyond the skull-base to the vertex to ensure inclusion of the entirety of the tumor. Squamous cell carcinoma of the head and neck preferentially spreads to regional lymph nodes, with nodal disease conferring decreased survival rates. Presence of distant metastatic disease at the time of diagnosis has been reported in 10% to 18% of patients [10], and its occurrence is directly linked to the stage of tumor [11-13].