Efficacy of Dose-Intensified Stereotactic Body Radiotherapy for Painful Vertebral Metastases
abstract
This abstract is available on the publisher's site.
Access this abstract nowBACKGROUND
The purpose of this randomised study was to determine whether dose-intensified stereotactic body radiotherapy (SBRT) for painful vertebral metastases results in increased rates of pain improvement compared with conventional external beam radiotherapy (cEBRT) (control) 6 months after treatment.
METHODS
This randomized, controlled phase 3 trial was conducted between November 2016 and January 2023, when it was stopped early. Patients were eligible if they were aged 18 years or older; had one or two painful, stable, or potentially unstable vertebral metastases; and had a life expectancy of 1 year or longer according to the investigator's estimates. Patients received 48.5 grays (Gy) in 10 fractions (with epidural involvement) or 40 Gy in five fractions (without epidural involvement) in the SBRT group and 30 Gy in 10 fractions or 20 Gy in five fractions in the cEBRT group, respectively. The primary end point was an improvement in the pain score at the treated site by at least 2 points (on a visual analog scale from 0 to 10 points) at 6-month follow-up. Data were analyzed on an intention-to-treat and per-protocol basis.
RESULTS
Of 214 patients who were screened for eligibility, 63 were randomized 1:1 between SBRT (33 patients with 36 metastases) and cEBRT (30 patients with 31 metastases). The median age of all patients was 66 years, and 40 patients were men (63.5%). In the intention-to-treat analysis, the 6-month proportion of patients who had metastases with pain reduction by 2 or more points was significantly higher in the SBRT group versus the control group (69.4% vs. 41.9%, respectively; two-sided p = .02). Changes in opioid medication intake relative to baseline were nonsignificant between the groups. No differences were observed in vertebral compression fracture or adverse event rates between the groups.
CONCLUSIONS
Dose-intensified SBRT improved pain score more effectively than cEBRT at 6 months.
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Additional Info
Disclosure statements are available on the authors' profiles:
Dose-intensified stereotactic body radiotherapy for painful vertebral metastases: A randomized phase 3 trial
Cancer 2024 Apr 06;[EPub Ahead of Print], M Guckenberger, C Billiet, D Schnell, C Franzese, M Spałek, S Rogers, JJ Stelmes, DM Aebersold, H Hemmatazad, F Zimmermann, J Zimmer, T Zilli, A Bruni, BG Baumert, F Nägler, P Gut, R Förster, I MadaniFrom MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
Guckenberger and co-investigators have published primary and secondary results from the DOSIS randomized controlled trial in Cancer. In summary, this was a phase III trial that investigated the role of dose-intensified stereotactic body radiotherapy (SBRT) for painful vertebral metastases compared with conventional external beam radiotherapy (cEBRT). Patients (aged ≥18 years; life expectancy, >1 year) with one or two distinct painful vertebral metastases were randomized to cEBRT (30 Gy/10 fractions; 20 Gy/5 fractions) or SBRT (40 Gy/5 fractions in cases without epidural extension; 48.5 Gy/10 fractions in cases with epidural extension). The primary endpoint was an improvement in the pain score (scale, 0–10 points) by at least 2 points at a 6-month follow-up. From 2016 to 2023, a total of 63 patients were enrolled (cEBRT, n = 30; SBRT, n = 33) before the trial was stopped early owing to slow accrual. The median follow-up duration was 10 months.
Overall, at 6 months, more patients who underwent SBRT had a >2-point pain reduction than those who underwent cEBRT (69% vs 42%; P = .02), with no statistical difference in the average pain score reduction between the groups (−3.4 [SBRT] vs −2.2 [cEBRT]; P = .24) and no statistical difference in opioid intake (5.1-mg reduction with SBRT vs 5.1-mg increase with cEBRT). No differences in complete pain response rates were observed. With regards to toxicity, no differences in the rates of compression fractures were noted, with no significant differences in quality-of-life measures between approaches.
How should these results be interpreted? Given the small size of the study and short follow-up, additional studies are needed before the routine implementation of SBRT for painful vertebral metastases. Further, given that no significant difference in average pain score reduction or opioid intake was noted with SBRT compared with cEBRT, it is unclear if the potential benefit of SBRT in this population is clinically meaningful. Additional context is provided by the results of RTOG 0631, a phase III trial of 339 patients, which found no difference in pain response with single-fraction radiosurgery compared with cEBRT in patients with one to three vertebral metastases.1 However, there are important findings from the current study with respect to toxicity, with no differences in compression fractures noted, which was consistent with the findings of RTOG 0631.
Finally, we must acknowledge the increased cost of care with SBRT approaches and, as such, studies incorporating the findings of this trial while evaluating the cost-effectiveness of an SBRT paradigm are needed.
Reference