SCORAD III: Randomized noninferiority phase III trial of single-dose radiotherapy (RT) compared to multifraction RT in patients (pts) with metastatic spinal canal compression (SCC).

LBA10004Background: SCC is a common complication of metastatic cancer. Most pts receive RT to improve neurological function and mobility and to relieve pain. There is no standard schedule (RT ranges from single dose 8Gy to 40Gy in 20 fractions). SCORAD III was conducted to show whether a single fraction is as effective as multifraction RT without compromising patient outcomes. Methods: Pts from 43 UK and 4 Australian sites were randomized (1:1) to receive external beam spinal canal RT as a single dose of 8Gy or 20Gy in 5 fractions; stratified by RT center, ambulatory status (AS), site of primary, and presence or absence of nonskeletal metastases. Eligible pts had spinal cord or cauda equina (C1-S2) compression confirmed by MRI/CT scan, treatable within a single radiation field, life expectancy >8 weeks (wks), no previous RT to the same area. Primary endpoint was AS at wk 8: graded 1 (full function) to 4 (no/flicker motor power). The noninferiority margin was 11% for comparing the proportion of patients wi...