Predictive Value of Nutritional Status for Symptomatic Radiation Pneumonitis in Patients with Thoracic Cancer Undergoing Radiotherapy.

The association between nutritional status and the risk of radiation pneumonitis (RP) in patients with thoracic cancer undergoing radiotherapy remains unclear and warrants further investigation. General clinical data between January 2021 and June 2024 were retrospectively analyzed. RP was diagnosed and graded according to the Common Terminology Criteria for Adverse Events (version 5), with symptomatic RP defined as grade ≥2. Predictive factors for RP were identified using least absolute shrinkage and selection operator and multivariate logistic regression analyses, followed by the development of a nomogram. The predictive performance of the nomogram was evaluated using the area under the curve (AUC) of receiver operating characteristic, calibration curve, and decision curve analysis. Controlling Nutritional Status (CONUT) scores and V₅ were identified as independent predictors of symptomatic RP and incorporated into the predictive model. The nomogram demonstrated excellent predictive capability (AUC: 0.851; 95% confidence interval: 0.801-0.902), with good accuracy and clinical application utility. Nutritional status is associated with the development of symptomatic RP. The pre-radiotherapy CONUT score can serve as a predictor of symptomatic RP, and its incorporation into the CONUT-V₅ model achieves better discriminative capacity. Improving nutritional status may be a simple way to prevent the development of symptomatic RP.