ESTRO 2025 - Abstract Book

S1489

Clinical – Mixed sites & palliation

ESTRO 2025

Purpose/Objective: Consolidating radiotherapy (RT) is considered standard of care in patients who underwent surgery for spinal metastases of solid malignancies (SBM). In this study, we propose an easily applicable prognostic score defining patients with poor survival as these patients are unlikely to benefit from postoperative RT. Material/Methods: In this retrospective analysis, we screened a total of 415 patients who received palliative RT for SBM at our center between 2015 and 2020. We selected 70 patients treated in a postoperative setting. Several factors easily assessable before dose prescription were evaluated for their prognostic impact in uni- and multivariate analysis. Factors, significantly associated in multivariate analysis were used to create a simple prognostic score. Results: Median overall survival (OS) following postoperative RT was 9.6 months (95%-CI: 7.3 - 15 months). 1-year and 2-year OS was 43% (95%-CI: 33%-57%) and 25% (95%-CI: 16%-39%) respectively. In univariate analysis, age below 70 years, Karnofsky performance score of 70 or higher, primary malignancies from prostate, breast, thyroid and kidney as well as limited metastatic spread (metastases in less than 2 organs outside of the RT field) showed significantly better survival compared to patients with other tumor entities or more tumor manifestations. In multivariate analysis, age (Hazard ratio (HR: 0.49), untreated metastases in two or more organs (HR: 2.05) and primary tumors with a favorable prognosis (HR: 0.47) had a statistically significant association with survival. We defined a score, stratifying patients into four risk groups with distinct prognosis. Median survival of these groups was 39.5 months (95%-CI: 32,5 months - NA), 12.7 months (95%-CI: 10.7 – 22.5 months), 6 months (95%-CI: 2.5 - 16 months) and 2.5 months (95%-CI: 2.1 months - NA) respectively ( Figure 1 ). The worst prognostic group had a 3-months survival rate of 33% (95%-CI: 13%-84%).