ESTRO 2024 - Abstract Book

S1903

Clinical - Mixed sites, palliation

ESTRO 2024

The trial was conducted between November 2016 and January 2023 and terminated earlier due to slow accrual. Of 214 patients screened for eligibility, 63 patients with 67 painful spinal metastases were randomized in ratio 1:1 and 58 patients received the assigned treatment. Treatment groups were well balanced in terms of demographic, clinical and metastases’ characteristics, although there were more males in the SBRT group than in the cEBRT group (26 [78.8%] vs. 13 [43.3%], respectively; P=0.004). (Table 1). The median age was 66 years (IQR 21-73). Non-small cell cancer (33.3%) and prostate cancer (17.5%) were most common cancer in both groups.

The median follow-up time of all patients was 10 months (IQR 5-15). The mean baseline pain score was 5.56 (standard deviation [SD] 2.32) in the SBRT group and 4.55 (SD 2.35) in the cEBRT group. The proportion of metastases with improvement in pain score by ≥2 points at 6 months was significantly higher in the SBRT group compared to the cEBRT group (69.4% [25 of 36]) vs. (41.9% [13 of 31], respectively; P=0.02) resulting in a relative risk of 1.7 (95% CI, 1.04-2.64) and an odds ratio of 3.1 (95% CI 1.15-8.61) (Table2). The 6-month mean reduction in pain score at the treated site relative to the baseline was not significantly different in the SBRT group compared to the control group (-3.43 [SD 3.97] vs. -2.24 [SD 2.68], respectively; P=0.24). At 6 months, the proportion of metastases with complete pain response, i.e., the pain score of 0 without increase in daily opioid intake, did not differ between the SBRT and cEBRT groups (22.2% [8 of 36] vs. 29.0% [9 of 31], respectively, P=0.53); while the proportion with pain