The objectives of this clinical trial were to determine the radioprotective effects and underlying biological mechanisms of Phellinus igniarius and its active components during radiotherapy in patients with thoracic malignant tumors.

The study group was given the formulation of Compound Phellinus igniarius decoction daily during radiotherapy, 150ml bid until the end of radiotherapy; The control group only received standard dose radiotherapy without the formulation of Compound Phellinus igniarius decoction intervention.

The baseline differences between the two groups were compared, including gender, smoking history, body mass index (BMI), pathological classification, median age of onset, inflammatory factors, tumor markers, TNM stage, KPS score, fatigue score, incidence and grade of radiation pneumonitis, incidence of other radiotherapy-related adverse reactions, and average radiation dose.

Investigators measured the levels of inflammatory factors and tumor markers in blood samples of patients in the two income groups, and administered questionnaires on the degree of fatigue and general status of patients. Metabolite changes and gut microbiota homeostasis in patient fecal samples were then detected by untargeted metabolomics and metagenomics.

Inclusion Criteria:

• Age ≥18 years, ECOG score≤2, possess adequate communication and comprehension abilities, and have an anticipated survival time exceeding 6 months
• Confirmed diagnosis of lung malignancy through imaging and pathological examination
• Indications for thoracic radiotherapy, DT:50-60Gy/20-30F
• Normal function of vital organs, including the heart, liver, kidneys, and gastrointestinal system

Exclusion Criteria:

• Patients with pre-existing pulmonary conditions, including idiopathic pulmonary fibrosis
• Individuals with systemic immune disorders
• Those with concurrent major infections
• Patients diagnosed with hematological disorders. All participants provided written informed consent