Long-Term Results of a Comparison Between 15 × 2.633 Gy and 20 × 2.0 Gy for Malignant Spinal Cord Compression in Patients with Longer Expected Survival Times

Background/Objectives: A considerable number of patients with malignant spinal cord compression (MSCC) and a longer expected lifespan do not receive upfront surgery but radiation therapy alone. These patients were suggested to benefit from radiation programs with total doses > 30 Gy in terms of better local progression-free survival (LPFS). A previous study compared such regimens, namely 15 × 2.633 Gy over three weeks (34 patients, prospective cohort) and 20 × 2.0 Gy over four weeks (239 patients, control), using a propensity score-adjusted approach. Both regimens were associated with similar rates of overall survival (OS) and LPFS. However, follow-up was limited to 12 months. For long-term survivors, a longer period of follow-up would be desirable. Therefore, the present study was initiated. Methods: Retrospective collection of additional data enabled us to provide OS- and LPFS-rates at 36 months following radiation therapy. Results: In the prospective cohort, 36-month rates of OS and LPFS were 27.0% and 89.7%, respectively. After application of the propensity score-adjusted Cox regression model, 36-month OS-rates (HR 1.454; 95% CI 0.748–2.828; p = 0.270) and LPFS-rates (HR 0.311; 95% CI 0.041–2.352; p = 0.258) appeared not considerably different. Late radiation myelopathy and pathologic vertebral fractures were not identified. Conclusions: The results of the current study suggest that the role of 15 × 2.633 Gy should be further investigated in selected patients with MSCC, particularly when considering its shorter overall treatment time in comparison to 20 × 2.0 Gy. Overall, our findings are hypothesis-generating rather than confirmatory.