Symptom experience and symptom distress in patients with malignant brain tumor treated with proton therapy: A five-year follow-up study

Background and purpose: Since patients with primary brain tumor are expected to become long-term survivors, the prevention of long-term treatment-induced side effects is particularly important. This study aimed to explore whether symptom experience and symptom distress change over five years in adults with primary brain tumors treated with proton therapy. An additional aim was to explore whether symptom experience and symptom distress correlate. Materials and methods: The study had a longitudinal observational design. Adult (>= 18 years) patients (n = 170) with primary brain tumors treated with proton therapy were followed over five years. Symptom experience and symptom distress were evaluated using the patient-reported Radiotherapy-Related Symptom Assessment Scale. Data from baseline, 1, 12, and 60 months were analyzed using non-parametric tests. Results: Of the 170 patients, the levels of symptoms and symptom distress were low. Fatigue increased at 1 (p=0.005) and 12 months (p=0.025) and was the most frequent symptom from baseline to 60 months' follow-up. Cognitive impairment increased at 12 (p=0.027) and 60 months (p<0.001) and was the most distressing symptom at 60 months' follow-up. There were significant, moderate to strong, correlations at all time points between symptom experience and symptom distress of fatigue, insomnia, pain, dyspnea, cognitive impairment, worry, anxiety, nausea, sadness, constipation, and skin reactions. Conclusion: Symptom experience and symptom distress changed in intensity over time with cognitive impairment as the most distressing symptom at 60 months. Future research should focus on identifying effective interventions aimed at alleviating these symptoms and reducing symptom distress for this vulnerable group of patients.