In a striking result presented at the ASTRO 2022 meeting, a randomized Phase II Trial have shown a survival benefit favoring prophylactic Radiation Therapy for Asymptomatic Bone Metastases. The multicenter study recruited 78 patients with metastatic solid tumors and more than five metastatic lesions on imaging (excluding oligometastatic disease), with at least one asymptomatic, high-risk lesion (defined according to size; location in the spine, hip, sacroiliac joint, or long bones).

Participants were randomized to radiation to all high-risk bone metastases vs standard care alone. The primary endpoint was skeletal-related events and secondary endpoints included the rates of hospitalization and overall survival.

Radiation therapy significantly reduced the incidence of skeletal-related events; 1.6% in the radiotherapy arm versus 29% with standard care (P < .001). In addition,radiation therapy also prolonged OS (HR: 0.49; p= 0.016)