Stereotactic Body Radiation Therapy Versus Conventional Radiation Therapy in Pain Relief for Bone Metastases: A Systematic Review and Meta-Analysis

Abstract

Purpose: This study aimed to investigate the difference in pain relief between stereotactic body radiation therapy (SBRT) and conventional radiation therapy (cRT) for patients with bone metastases.

Methods and materials: Clinical trials and observational studies comparing SBRT versus cRT for bone metastases were retrieved. The main endpoint was pain relief after radiation therapy; the secondary endpoints were pain score change, local progression-free survival, reirradiation rate, and toxic events. When there was a significant heterogeneity, the random-effects model was applied. Otherwise, the fixed-effects model was used. Analyses of all included studies were performed first, followed by analyses of randomized controlled trials (RCTs) only.

Results: Six RCTs, 1 prospective cohort study, and 3 retrospective observational studies were enrolled. Between 2004 and 2019, 448 patients received SBRT, and 445 patients received cRT. All prospective studies defined the lesions as oligometastatic. Pooled results based on all included studies indicated that SBRT was generally associated with a higher overall relief rate (P < .001 at 3 months; P = .015 at 6 months) and complete relief rate (P = .029 at 1 month; P < .001 at 6 months). Pooled results based on RCTs indicated that at 3 and 6 months, SBRT was associated with a higher overall relief rate (P < .001 and P = .017, respectively) and complete relief rate (P < .001 and P < .00, respectively). Subgroup analyses indicated that in more cases, the analgesic advantage of SBRT was more obvious when spinal lesions were irradiated, when the difference in the mean biological effective dose (BED) was less, or when intensity modulated radiation therapy was used to deliver SBRT.

Conclusions: Excessive elevation of BED introduces the risk of diminishing the analgesic effect of SBRT. SBRT delivered using intensity modulated radiation therapy is preferred for pain relief in spinal oligometastases. More RCTs are required to determine the most appropriate BED or dose regimen for SBRT.