Patient-Reported Outcome Measures and Dosimetric Correlates for Early Detection of Acute Radiation Therapy–Related Esophagitis

Background: We investigate the time to and clinical factors associated with patient-reported difficulty swallowing in lung cancer patients treated with radiation therapy (RT). Methods: Between October 2016 and October 2019, lung cancer patients treated with conventionally fractionated RT at a tertiary cancer center were identified. Weekly, patients reported difficulty swallowing (patient-reported outcome version of the Common Terminology Criteria for Adverse Events [PRO-CTCAE] v.1: 0-none, 1-mild, 2-moderate, 3-severe, 4-very severe). Physicians graded dysphagia (CTCAE v.4: 0-none, 1-symptoms without altered intake, 2-symptomatic; altered eating/swallowing, 3-severely altered eating/swallowing, 4-life-threatening consequences, 5-death). Tumor-related difficulty swallowing was not recorded at baseline; thus, patients reporting ≥moderate symptoms ≤7 days of RT start were excluded. We evaluated the time to new patient reports of ≥moderate difficulty swallowing and CTCAE grade 2+ dysphagia and development over time using the cumulative incidence method. Multivariable logistic regression evaluated associations between clinical factors, esophageal V60, and development of esophageal symptoms. Results: Of the 200 patients identified: median age was 69 years, 52% were male, and 89% had stage III+ disease. Patients received a median of 63 Gy with chemotherapy (91.5%). At least moderate difficulty swallowing during RT was reported by 76 of 200 patients (38%); clinicians rated dysphagia as altering oral intake or worse for 26 of 200 (13%). Median time to first report of symptoms was 21 days (interquartile ratio [IQR], 18-34.5) for the 76 patients who reported ≥moderate symptoms and 33 days (IQR, 24-42) in the 26 patients whose provider reported grade 2+ dysphagia. The 30-day incidence of patient-reported ≥moderate swallowing difficulty and provider grade 2+ dysphagia was 26% (95% CI: 20%-32%) and 6% (95% CI: 3%-9%), respectively. Esophageal V60 >7 % was the clinical factor most associated with patient-reported ≥moderate esophageal symptoms (odds ratio 6.1, 95% CI: 3.0-12.3). Conclusions: Patients report at least moderate difficulty swallowing more often and earlier than providers report grade 2+ dysphagia. Esophageal V60 ≥7% was most associated with development of moderate severity or worse patient-reported swallowing difficulty.