Abstract: Objective To investigate the symptom clusters and their longitudinal variations in patients with gastrointestinal cancer at different stages of  radiotherapy. Methods A convenience samplingapproach was employed to select 130 patients with gastrointestinal cancer undergoing radiotherapy at the Second Affiliated Hospital of Shandong First Medical University from September 2023 to May 2024. The Anderson symptom rating scale was used to assess the symptom clusters at three distinct time points:  seven days prior to the initiation of radiotherapy (T0)， mid⁃radiotherapy (during the 15th session， T1)， and thirty days post⁃radiotherapy (T2). Exploratory factor analysis was used to identify symptom clusters， while generalized estimating equations were applied to analyze the repeated measurement data. Results Across the three time points， distress was identified as the symptom with the highest incidence and severity， whereas emotion interference was the most prevalent and severe symptom interference item. Four distinct symptom clusters were identified, among which the emotion⁃energy deficiency， eating difficulty， and nervous system symptom clusters persisted from T0 to T2,whereas the numbness⁃nausea symptom cluster was observed only at T1. The severity scores of each symptom cluster across the three time points were statistically significant (P<0.001). Further pairwise comparisons revealed that the severity of all symptom clusters was greater at T1 compared to T0 and T2 (P<0.001). Conclusions Patients with gastrointestinal cancer experience multiple symptom disturbances and clusters during radiotherapy， with severity progressively increasing as chemotherapy advances. Implementing targeted  interventions for these symptom clusters may help alleviate symptom burden and enhance the quality of life for patients with gastrointestinal cancer.

Key words: Gastrointestinal cancer, Radiotherapy, Symptom cluster, Longitudinal study