Randomized phase 2 study of single-fraction versus multifraction SABRT for pulmonary oligometastases

Stereotactic ablative body radiotherapy (SABRT) allows precise delivery of high biologic effective doses of radiation. However, no high-level evidence or consensus is available on the optimal dose and fractionation schedule for SABRT in oligometastatic disease. The phase 2 SAFRON II study in Australia and New Zealand compared single-fraction SABRT and multifraction SABRT for pulmonary oligometastases. The study found no significant differences for the primary end point of severe toxicity (5% versus 3%). The secondary end points of efficacy, survival, and quality of life were also not different between the study arms. The authors conclude that single-fraction, being of shorter duration, may be preferred from resource and patient perspective.