PSA Doubling Time Predicts for the Development of Distant Metastases for Patients Who Fail 3DCRT or IMRT using the Phoenix Definition

Abstract

PSA doubling time (PSADT) is commonly used as an indication for salvage androgen deprivation therapy (ADT) for PSA failure following RT. Previously, we have shown that PSADT of <12 months is an important predictor for the development of distant metastasis following 3DCRT using the former ASTRO definition of biochemical failure. The Phoenix definition (nadir+2) is a more robust definition of PSA failure following RT. We sought to determine if this definition to determine if this approach is still valid with IMRT in a larger dataset with longer follow-up.