Does timing matter? A single-institution analysis of vertebral augmentation before or after radiotherapy in the treatment of painful spine metastases

OBJECTIVE: Vertebral augmentation (VA), including vertebroplasty and kyphoplasty, has become pivotal in alleviating pain and disability associated with pathological compression fractures of the spine. However, there is no existing guidance informing the ideal timing of radiotherapy (RT) and VA, with a theoretical concern of tumoral seeding if adjuvant. This study compared locoregional cancer recurrence in patients who underwent neoadjuvant versus adjuvant RT. METHODS: The authors conducted a retrospective review of all adult cancer patients treated with VA and RT within 3 months between 2009 and 2023 at the University Health Network in Toronto, Ontario, Canada. They investigated locoregional recurrence (LRR), defined as recurrence within the RT field as well as 1 vertebral body above and below. Time to recurrence was estimated using cumulative incidence analysis and compared using Gray's test. Competing risk regression was used to compare the recurrence risk in the full cohort and in a matched cohort using propensity scores informed by biologically effective dose, radiosensitivity, and vertebral levels. RESULTS: The authors included 180 patients-45 received adjuvant RT and 135 received neoadjuvant RT. The mean ± SD age of patients was 63.8 ± 12.7 years and about half were female (52%). The mean time between VA and adjuvant RT was 30 ± 26 days and 41 ± 23 days between neoadjuvant RT and VA (p < 0.001). Forty patients (22%) had LRR, with a median (range) time from RT to recurrence of 2.4 (0.1-96) months. Patients who underwent neoadjuvant RT had a reduced risk of LRR (subdistribution hazard ratio [sHR] [95% CI] 0.30 [0.16-0.56], p < 0.001). This observation did not change after propensity score matching (sHR [95% CI] 0.41 [0.19-0.88], p = 0.02). CONCLUSIONS: The authors observed a higher risk of LRR in patients who underwent adjuvant versus neoadjuvant RT in relation to VA. In the setting of painful spine metastases, RT should be considered before VA for improved tumor control.