Planning for the Effect of the SC.24 Trial on Spine Stereotactic Body Radiation Therapy Utilization at a Tertiary Cancer Center

Abstract

The goal of this study was to assess the potential real-world effect of the recently reported SC.24 trial on spine stereotactic body radiation therapy (SBRT) utilization. We estimated the proportion of patients treated with conventional radiation therapy (CRT) who would have been eligible for spine SBRT per trial inclusion criteria and analyzed the potential estimated increased costs to our institution. This was a retrospective review of patients who received spine CRT at our institution between August and October 2020. Data abstracted included demographics, SC.24 eligibility criteria, provider-reported pain response, and survival. A cost analysis and time survey was performed using institutional and provincial data. Of 73 patients reviewed, 24 patients (33%) were eligible. The most common exclusion factors included irradiation of ≥3 consecutive spinal segments (n=32, 44%), Eastern Cooperative Oncology Group performance status >2 (n=17, 23%), and symptomatic spinal cord compression (n=13, 18%). Of eligible patients, the mean age was 68.92 years, median spinal instability in neoplasia score was 8 (interquartile range, 7-9), and median Eastern Cooperative Oncology Group performance status was 2 (interquartile range, 1-2). The most common primary cancer types among eligible patients were lung (n=10) and breast (n=4). The median survival of eligible patients was 10 months (95% confidence interval, 4 months to not reached) with 58% surviving longer than 3 months. Of patients who had subjective pain documented after CRT, 54% had at least some response. The cost of spine SBRT was estimated at CA$4764.80 compared with $3589.10 for CRT, and tasks for spine SBRT took roughly 3 times as long as those for CRT. One-third of patients who received palliative spine CRT met eligibility criteria for SC.24. This possible expanded indication for spine SBRT can have a substantial effect on resource utilization. These data may be useful in guiding resource planning at institutions looking to commence a spine SBRT program.