Headline: Prophylactic radiation of high-risk skeletal mets is a slam dunk.
The Study: This one is poised to meaningfully expand the pool of patients with metastatic disease who benefit from our healing rays. This innovative prospective randomized phase 2 trial at MSKCC enrolled 78 patients with 122 asymptomatic high-risk skeletal mets to +/- prophylactic radiation. It’s important to understand the inclusion criteria: in a refreshing turn from recent trends, all patients had decidedly polymetastatic disease with more than 5 sites of metastatic disease. High-risk was defined as any bulky disease (≥2 cm) or involvement of junctional spine, posterior spinal elements, hip or sacroiliac joint, or one- to two-thirds cortical thickness of a long bone. In other words, this captured a lot of bone mets. Patients were randomized to standard treatment or prophylactic palliative radiation to all high risk lesions. First up, the logical primary endpoint of any skeletal-related event (fracture, cord compression, or local treatment upon symptoms) within 12 months of randomization was virtually eliminated with upfront radiation (1.6%) versus without (29%), which resulted in fewer related hospitalizations over the same time period (0 versus 4). The secondary endpoint of pain at 3 months was also significantly reduced. Interestingly, at a median follow-up of 2.4 years, the risk of death was halved in the radiation arm (HR 0.50).
TBL: This randomized phase 2 trial found that prophylactic radiation to high risk bone metastases significantly reduces the risk of skeletal events. | Gillespie, ASTRO 2022