Patient-reported outcome and prognostic factors for survival in patients with metastases in soft tissue treated with palliative radiotherapy

Purpose: To determine the overall result of treatment with palliative radiotherapy for patients with soft tissue metastases and to identify prognostic factors for overall survival. Methods and materials: From September 2015 until April 2023, 120 patients were included. Treatment outcome was reported via telephone consultations at four and eight weeks after the last fraction. Patients who reported benefit were classified as responders, while those without benefit were classified as non-responders. Results: The most frequent complaints were pain (n = 104), swelling (n = 20) or functional disability (n = 19). There was a decrease or disappearance in 61% of complaints 8 weeks after last fraction of treatment. Median overall survival was 4.3 months (95% CI 2.4-9.3). 26 patients (22%, 95% CI 14%-29%) died within 2 months. From the 94 patients alive two months after treatment 66 responders had a significant better survival compared to 25 non-responders (6.6 vs 3.8 months, p = 0.005).Multivariable analysis identified 5 prognostic factors for overall survival: PTV-volume, time from diagnosis to treatment, total number of metastases, systemic treatment options after radiotherapy, and number of organs. Conclusion: Palliative radiotherapy for patients with soft tissue metastases provided benefit in 61% of complaints that were the reason for treatment. Responders had a significantly better survival than non-responders. Although 5 prognostic factors for survival were identified, further research is needed to identify patients who benefit from palliative radiotherapy.