Top Line: Advanced molecular imaging can guide salvage radiation after prostatectomy.
The Study: Virtual ASTRO 2020 first brought us results of the EMPIRE-1 trial, and here we have the full publication. In it, 165 men with detectable PSA after radical prostatectomy and no metastases on conventional bone scan and CT or MRI were randomized to +/- F18-fluciclovine PET prior to salvage radiation. The goal of this trial was to determine if more advanced imaging could improve the apparent effectiveness of salvage radiation. Prior to randomization, providers stated their intended target volumes as either fossa (69%) or pelvis + fossa (31%) and use and duration of androgen deprivation therapy (ADT). In the fluciclovine arm, radiation and target volumes could then change based on imaging findings. Those with extrapelvic or skeletal mets (5%) got no radiation, those with pelvic nodal mets (34%) got pelvic + fossa radiation, and those with fossa uptake (41%) or no uptake (20%) got fossa-only radiation. This resulted in a change from the original treatment plan for 35%. The rate of 3-year event free survival (EFS) was significantly higher when fluciclovine PET was incorporated (76%) than when it wasn’t (63%). By 4 years, EFS was almost 25% higher with using fluciclovine PET (75 vs 51%). On multivariable analysis, fluciclovine PET was still associated with longer EFS. Of note, the median PSA was 0.3 and 25% had a PSA of 1 or higher. A final note: additional boost doses to sites of fluciclovine uptake were not allowed, but this will be addressed on EMPIRE-2.
TBL: While there’s nothing therapeutic about fluciclovine PET, using it to guide salvage radiation after prostatectomy changes the treatment plan in more than one in three patients and is associated with better treatment outcomes. | Jani, Lancet 2021