Unplanned Hospitalization and Emergency Department Use in Patients With Head and Neck Cancer Receiving Radiotherapy

This is a single-center, prospective, observational cohort study of patients with head and neck cancer (HNC) who receive intensity-modulated radiotherapy (IMRT, including volumetric-modulated arc therapy, VMAT). HNC is the sixth most common cancer worldwide; in China, approximately 148,000 new cases and 78,000 deaths were reported in 2021. During and after radiotherapy, patients frequently develop severe acute toxicities-radiation-induced oral mucositis, orofacial pain, xerostomia, dysphagia, dehydration, and myelosuppression-that may lead to unplanned hospitalization or emergency department (ED) visits. Up to 28%-55% of HNC patients experience an ED visit or unplanned admission within 90 days of treatment, and rates may approach 58% in those receiving concurrent chemoradiotherapy. These events interrupt treatment, worsen prognosis, and impose a substantial burden on patients and the healthcare system. Consecutive eligible patients will be enrolled before IMRT and followed from the first treatment fraction through 30 days after radiotherapy completion. At baseline, during radiotherapy, and before discharge, we will collect demographic and socioeconomic data; behavioral exposures (tobacco, alcohol, betel-nut use); comorbidity (Charlson Comorbidity Index, frailty); nutritional status (NRS-2002, BMI, weight loss); psychological screening; tumor- and treatment-related information; patient-reported symptoms (MDASI-HN); and serial blood tests from which inflammatory-nutritional indices (PNI, NLR, PLR, LMR, SII) are derived. The primary outcome is any unplanned hospitalization, including outpatient-to-inpatient transfer during treatment, ED-led admission, and post-treatment readmission; ED use is a key secondary outcome. We will estimate the incidence and reasons for these events, identify associated factors, characterize longitudinal symptom and laboratory trajectories, and develop and internally validate a risk prediction model (multivariable logistic regression, with a random forest model for comparison, presented as a nomogram). The model will support early identification of high-risk patients and targeted supportive interventions to reduce preventable acute-care utilization.

Inclusion Criteria: 1. Histologically confirmed malignant tumor of the head and neck (oral cavity, oropharynx, hypopharynx, larynx, nasopharynx, nasal cavity/paranasal sinus, or salivary gland). 2. Age ≥ 18 years. 3. Scheduled to receive intensity-modulated radiotherapy (IMRT) or volumetric-modulated arc therapy (VMAT), either definitive or postoperative, with or without concurrent chemotherapy or targeted therapy. 4. Able to understand and complete the study questionnaires and provide written informed consent. Exclusion Criteria: 1. Not receiving IMRT/VMAT (e.g., conventional 2D or 3D-CRT only). 2. Previous radiotherapy to the head and neck region (re-irradiation). 3. Treated primarily for another major disease without anti-tumor therapy for HNC. 4. In-hospital death or withdrawal/forgoing of anti-tumor treatment before enrollment. 5. Unable to cooperate with follow-up (e.g., loss of contact, severe cognitive or psychiatric disorder). 6. Pregnancy or breastfeeding. 7. Concurrent active malignancy other than HNC (except non-melanoma skin cancer or in situ cervical cancer).