5500/20 vs. SABR or Brachytherapy for PRimary OligoMetastatic Prostate Cancer Treatment (PROMPT)

We will investigate whether ultrahypofractionation using stereotactic ablative radiotherapy (SABR) or brachytherapy is as well-tolerated as moderately hypofractionated external beam radiotherapy (EBRT) for treating the prostate in patients with oligometastatic prostate cancer. Secondary aims include assessment of progression-free survival (PFS) and overall survival (OS) as well as cost-effectiveness. We hypothesize that ultrahypofractionation will maintain favorable toxicity profiles and quality of life while achieving comparable or better efficacy, thereby providing a convenient and cost-effective alternative to moderately hypofractionated EBRT.