Salvage therapy of intraprostatic failure after radical external-beam radiotherapy for prostate cancer: A review

Radical external-beam radiotherapy (EBRT) is a standard treatment for prostate cancer (PC) patients. Despite this, the rate of intraprostatic relapses after primary EBRT is still not negligible. There is no consensus on the most appropriate management of these patients after EBRT failure. Treatment strategies after PC relapse are strongly influenced by the effective site of the tumor recurrence, and thus the instrumental evaluation with different imaging techniques becomes crucial. In cases of demonstrated intraprostatic failure, several systemic (androgen deprivation therapy) or local (salvage prostatectomy, cryotherapy, high-intensity focused ultrasound, brachytherapy, stereotactic EBRT) treatment options could be proposed and are currently delivered by clinicians with a variety of results. In this review we analyze the correct definition of intraprostatic relapse after radiotherapy, focusing on the recent developments in imaging to detect intraprostatic recurrence. Furthermore, all available salvage treatment options after a radiation therapy local failure are presented and thoroughly discussed.