Ultra-hypofractionation for the treatment of macroscopic prostate bed recurrence: a focus on stereotactic radiotherapy and brachytherapy.

Purpose of review: The aim of this review is to assess contemporary studies on ultra-hypofractionated local salvage therapies - stereotactic body radiation therapy (SBRT) and brachytherapy - for macroscopic prostate bed recurrence after radical prostatectomy, with or without prior external beam radiotherapy (EBRT), and to highlight knowledge gaps guiding current trials.

Recent findings: Recent studies, primarily retrospective, report 1-year biochemical control rates of 56-88% for SBRT and up to 87% for high-dose-rate brachytherapy, with low to moderate rates of severe genitourinary toxicity. Higher biologically effective doses and limited tumour volume predict improved outcomes, yet focal-only strategies carry some risk of out-of-field relapse within the prostate bed. The role of concomitant androgen deprivation therapy remains unclear. Several phase II trials (e.g. STARR, PROSTARE, REPAIR, and HypoFocal SRT) are underway.

Summary: Ultra-hypofractionated salvage radiotherapy offers effective disease control with manageable toxicity for selected patients and may defer systemic therapy. Further studies are needed to standardize imaging, biopsy confirmation, dose escalation, and systemic treatment integration. Prospective, randomized studies are crucial to define optimal modality, target volume, and patient selection criteria before widespread adoption.