Siva S, Bressel M, Mai T, et al. - Compared with multifraction stereotactic ablative body radiotherapy (SABR) for pulmonary oligometastases, single-fraction SABR is of shorter duration and therefore may be favored from resource and patient viewpoints.

• A multicenter, unblinded, phase 2 randomized clinical trial of 90 patients with 1 to 3 oligometastases to the lung.

• 87 patients with 133 pulmonary oligometastases received single fraction of 28 Gy (single-fraction arm) or 4 fractions of 12 Gy (multifraction arm) to each oligometastasis.

• No difference in the primary endpoint of severe toxicity (grade 3 or higher treatment-related adverse events occurring within 1 year of SABR) was found between the single-fraction arm (5%) vs in the multifraction arm (3%).

• Freedom from local failure (hazard ratio [HR], 0.5), overall survival (HR, 1.5), or disease-free survival (HR, 1.0) did not differ significantly between the multifraction arm and single-fraction arm.

• No significant differences were noted in patient-reported outcomes.

• Neither arm was superior in safety, efficacy, or symptom burden; however, single-fraction SABR was more efficient to deliver.