A randomized phase II/III study comparing stereotactic body radiotherapy (SBRT) versus conventional palliative radiotherapy (CRT) for patients with spinal metastases (NCT02512965).

TPS10129 Background: Innovative radiotherapy technology and modern imaging capabilities enable the use of Stereotactic Body Radiotherapy (SBRT) to treat patients with spinal metastases to optimize tumour control and palliation compared to standard conventional radiotherapy. No randomized clinical trial evidence exists directly comparing the two treatment strategies. Methods: SC.24 is a Canadian Cancer Trials Group randomized phase II/III study comparing standard conventional radiotherapy (20 Gy/5fr) to SBRT (24 Gy/2fr) in patients with solid tumours and MRI documented, painful spinal metastases suitable for RT. The primary accrual objective for the phase II portion of the study was met in January 2017 and the study continues as a randomized phase III study with a primary outcome measure of complete pain response at 3 months post radiotherapy. Secondary objectives include: measurement of complete pain response at 6 months; radiation site progression free survival at 3 and 6 months; adverse event profile, health related QOL and compliance with RT QA measures. Biobanking for future correlative studies is included in study design. Statistical design: The statistical assumptions for the phase III study include estimated complete pain response rates of 10% and 30% for the CRT and SBRT treatment arms respectively. Using a two sided alpha = 0.05 and power = 80% the sample size for the phase III study is 152, taking into account a 5% drop out rate. Conduct to Date: Study activation: July 2015. Accrual to date: 58. Supported by CCSRI grant 021039 Clinical trial information: NCT02512965.