Single-Fraction Stereotactic vs Multifraction Radiotherapy for Pain Relief in Predominantly Nonspinal Bone Metastases
In a single-center phase II trial reported in JAMA Oncology, Nguyen et al found that single-fraction stereotactic body radiotherapy (SBRT) was associated with improved pain relief vs conventional multifraction radiotherapy in patients with mostly nonspinal bone metastases.
In the noninferiority study, 160 patients at The University of Texas MD Anderson Cancer Center were randomly assigned between September 2014 and June 2018 to receive single-fraction SBRT (12 or 16 Gy, depending on lesion size; n = 81) or standard multifraction radiotherapy (30 Gy in 10 fractions; n = 79).
The primary endpoint was pain response: complete response was a pain score of 0 (0–10 scale) at the treated site and no increase in daily morphine-equivalent dose; partial response was a reduction in pain score ≥ 2 points from baseline and no morphine-equivalent dose increase. Pain failure was defined as worsening pain score (≥ 2 points), an increase in morphine-equivalent dose ≥ 50%, reirradiation, or pathologic fracture. It was hypothesized that SBRT would be noninferior to conventional radiotherapy.
Pain Response
Pain response (complete or partial) was more common in the SBRT group at 2 weeks (62% vs 36%, P = .01), 3 months (72% vs 49%, P = .03), and 9 months (77% vs 46%, P = .03). No differences between groups were observed in treatment-related toxic effects or quality-of-life scores. Among all patients, local failure occurred in 0% of patients in the SBRT group at 6 months and 24 months, whereas the cumulative incidence of local failure in the multifraction radiotherapy group was 4.2% at 6 months and 9.7% at 24 months (P = .02).
The investigators concluded, “Delivering high-dose, single-fraction SBRT seems to be an effective treatment option for patients with painful bone metastases. Among evaluable patients, SBRT had higher rates of pain response (complete response and partial response) than did [multifraction] radiotherapy, and thus should be considered for patients expected to have relatively long survival.”
Quynh-Nhu Nguyen, MD, of the Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, is the corresponding author for the JAMA Oncology article.
Disclosure: This study was supported by a grant from the National Cancer Institute. For full disclosures of the study authors, visit jamanetwork.com.
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