Comparison of two radiotherapy regimens for metastatic spinal cord compression: Subgroup analyses from a randomized trial

Background/Aim: According to our randomized trial, 5×4Gy was comparable to 10×3Gy for metastatic spinal cord compression. Since it remained unclear whether findings applied to poor and intermediate prognoses patients, subgroup analyses were performed. Patients and Methods: In patients with poor prognoses, 58 received 5×4Gy, 53 received 10×3Gy. In intermediate-prognoses patients, numbers were 43 and 49. Results: In patients with poor prognoses, 1-month overall response (OR) was 85% after 5×4Gy and 10×3Gy (p=0.99), improvement 38% vs. 42%, ambulatory status 60% vs. 64% (p=0.83), 6-month local progression-free survival (LPFS) 75% vs. 69% (p=0.74) and 6-month overall survival (OS) 26% vs. 19% (p=0.43). In patients with intermediate prognoses, 1-month OR was 89% after 5×4Gy and 93% after 10×3Gy (p=0.85), improvement 39% vs. 45%, ambulatory status 84% vs. 82% (p=0.90), 6-month LPFS 79% vs. 92% (p=0.17) and 6-months OS 65% vs. 58% (p=0.65). Conclusion: 5×4Gy was not significantly inferior to 10x3Gy in both subgroups.