A nurse is planning care for a client who is receiving targeted radiation therapy to the neck. The nurse should plan to monitor the client for which of the following as an adverse effect of this therapy?

Targeted radiation therapy to the neck affects rapidly dividing cells in the oral mucosa and surrounding tissues. While it is directed at malignant cells, surrounding normal tissues such as the mucous membranes, salivary glands, and skin can also be damaged. This often results in localized inflammatory and degenerative changes within the mouth. Nurses must anticipate and monitor for oral complications that can affect nutrition, comfort, and risk of infection. A. Decreased tear production is more commonly associated with radiation therapy directed at the orbital region or conditions affecting the lacrimal glands, not the neck. While some systemic effects of radiation may occur, dry eyes are not a primary expected adverse effect of neck-focused radiation therapy. B. Constipation is not a direct adverse effect of neck radiation therapy. Gastrointestinal changes such as constipation are more commonly associated with abdominal or pelvic radiation, opioid use, or decreased mobility. Neck radiation primarily affects the oral cavity and upper airway structures. C. Peripheral neuropathy is more commonly associated with certain chemotherapy agents rather than localized radiation therapy to the neck. Radiation-induced nerve damage can occur but is typically related to high-dose exposure or specific anatomical involvement, not routine neck radiation. D. Mouth ulcers (oral mucositis) are a common adverse effect of radiation therapy to the neck due to damage to rapidly dividing epithelial cells in the oral mucosa. This leads to inflammation, ulceration, pain, and difficulty eating or swallowing. It also increases the risk of secondary infection and requires supportive oral care interventions.