Prostate-specific antigen doubling time predicts the development of distant metastases for patients who fail 3-dimensional conformal radiotherapy or intensity modulated radiation therapy using the Phoenix definition

PSADT remains a significant predictor of clinical failure and CSS for men treated with 3DCRT or intensity modulated radiotherapy who fail according to the Phoenix definition. Immediate use of ADT in patients with PSADT <6 months is significantly associated with improved CSS, although the benefit is less apparent in patients with longer PSADT. These results further refine the role of PSADT in predicting which patients may benefit from salvage ADT and those who may be observed expectantly.