Single-Fraction Stereotactic vs Conventional Multifraction Radiotherapy for Pain Relief in Patients With Predominantly Nonspine Bone Metastases: A Randomized Phase 2 Trial
Mené sur 106 patients atteints d'un cancer et présentant des métastases osseuses, cet essai de phase II compare l'efficacité, en termes de réduction de la douleur, d'une radiothérapie corporelle stéréotaxique ciblant les métastases et dispensée en une seule fraction et d'une radiothérapie conventionnelle à doses standard
Importance : Consensus is lacking as to the optimal radiotherapy dose and fractionation schedule for treating bone metastases. Objective : To assess the relative efficacy of high-dose, single-fraction stereotactic body radiotherapy (SBRT) vs standard multifraction radiotherapy (MFRT) for alleviation of pain in patients with mostly nonspine bone metastases. Design, Setting, and Participants : This prospective, randomized, single-institution phase 2 noninferiority trial conducted at a tertiary cancer care center enrolled 160 patients with radiologically confirmed painful bone metastases from September 19, 2014, through June 19, 2018. Patients were randomly assigned in a 1:1 ratio to receive either single-fraction SBRT (12 Gy for ≥4-cm lesions or 16 Gy for <4-cm lesions) or MFRT to 30 Gy in 10 fractions. Main Outcomes and Measures : The primary end point was pain response, defined by international consensus criteria as a combination of pain score and analgesic use (daily morphine-equivalent dose). Pain failure (ie, lack of response) was defined as worsening pain score (≥2 points on a 0-to-10 scale), an increase in morphine-equivalent opioid dose of 50% or more, reirradiation, or pathologic fracture. We hypothesized that SBRT was noninferior to MFRT. Results : In this phase 2 noninferiority trial of 96 men and 64 women (mean [SD] age, 62.4 [10.4] years), 81 patients received SBRT and 79 received MFRT. Among evaluable patients who received treatment per protocol, the single-fraction group had more pain responders than the MFRT group (complete response + partial response) at 2 weeks (34 of 55 [62%] vs 19 of 52 [36%]) (P = .01), 3 months (31 of 43 [72%] vs 17 of 35 [49%]) (P = .03), and 9 months (17 of 22 [77%] vs 12 of 26 [46%]) (P = .03). No differences were found in treatment-related toxic effects or quality-of-life scores after SBRT vs MFRT; local control rates at 1 and 2 years were higher in patients receiving single-fraction SBRT. Conclusions and Relevance : 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 + partial response) than did MFRT and thus should be considered for patients expected to have relatively long survival.