Most cancers arising from the upper aerodigestive mucosa are squamous cell carcinomas (SCC) or one of its variants including lymphoepithelioma, spindle cell carcinoma, verrucous carcinoma, and undifferentiated carcinoma. Adenocarcinoma, mucoepidermoid carcinoma, and adenoid cystic carcinoma are seen in the major salivary glands including the parotid, submandibular and sublingual glands, as well as the minor salivary glands. Merkel cell carcinoma most frequently arises on the head and neck skin and is among the cutaneous neuroendocrine neoplasms. Merkel cell tumors follow an aggressive disease course with common locoregional and distant failure. Lymphomas, solitary plasmocytomas, soft tissue sarcomas, melanomas, and other malignant and benign neoplasms represent the remaining cases.

A meticulous physical examination including the palpation of the head and neck lymph node regions, direct or indirect visualization of the primary site by mirror, or fiberoptiscopic examination is an important part of initial patient assessment. Imaging studies include computed tomography (CT) and/or magnetic resonance imaging (MRI) of the head and neck region and X-ray examinations of the skull, sinuses, and soft tissue. Barium swallow may be suggested for symptomatic patients, along with chest radiograph and bone scan to exclude metastatic disease. Integrated positron emission tomography (PET)/CT imaging may assist in precise definition of locoregional disease and distant metastases. It may also aid in locating occult tumors in the setting of an unknown primary and may be beneficial for detecting recurrent disease after treatment. Viral titers may be elevated in some patients, anti-Epstein–Barr virus antibody titers may be used to assist in the diagnosis of nasopharyngeal cancers in some cases. Laryngoscopy, bronchoscopy, and esophagoscopy may be considered in the setting of suspected synchronous aerodigestive primary.

Staging of head and neck cancers is mostly based on clinical diagnostic information about the tumor size, extension, and presence of involved lymph nodes. Decision making for adjuvant treatment warrants accurate surgical–pathological classification.

Radiation therapy process for head and neck cancers generally include the following steps:

Positioning of the patient for treatment may depend on the specific cancer type being treated and the objectives of the treating physician concerning the tumor volume and normal tissue sparing. Patient lies supine in the majority of cases with the neck extended and the head on headrest. Surgical scars and palpable nodes may be wired. The patient should be immobile during therapy. Movements may cause changes in the treatment area and increase side effects, thus affecting treatment success. The patient should be positioned in the most comfortable, easily reproducible way suitable for the irradiated region of interest.

Optimum immobilization is a major component of radiotherapy management in head and neck cancers. The importance of setup reproducibility is becoming more important with the need for tighter margins and steep dose gradients in the modern radiotherapy era.

Thermoplastic face mask is frequently used for immobilization of patients with head and neck cancers (Fig. 1.2).

Such a mask should not only be tight but also there should be no space between the patient’s skin and the mask. The mask should be checked during every setup procedure for tightness or looseness (due to edema or weight loss) and should be remade adaptively if necessary.