RE-irradiation for Isolated FOCal Recurrence of Prostate Cancer With Ultrahypofracted SBRT

Prostate cancer (PCa) is one of the most frequently diagnosed malignancies in men worldwide, with the highest prevalence observed in developed countries. Patients affected by localized disease can be treated with several local modalities, including radical prostatectomy (RP), external beam radiotherapy (EBRT) and brachytherapy (BT). Although the advances in treatment strategies, after primary treatment 5 to 60% of men experience biochemical recurrence (BCR).

Inclusion Criteria: * Age \> 18 and \< 80 years * Histologically confirmed adenocarcinoma of the prostate initial diagnosis * History of a previous adjuvant/salvage RT following prostatectomy or curative RT * Diagnosis of local recurrence at the restaging imaging in hormone sensitive patients (maximum 1 prostate bed recurrence and 3 intraprostatic recurrences) * DICOM plan of the previous RT course * No evidence of greater than grade 2 according to Common Terminology Criteria for Adverse Events (CTCAE) genitourinary (GU) or gastrointestinal (GI) late adverse events from the previous RT course * Eastern Cooperative Oncology Group (ECOG) Performance Status \10 mL/s) or IPSS \< 15 * Written informed consent for treatment and research purpose Exclusion Criteria: * Evidence of distant metastasis at the restaging imaging * Patients with current concomitant anticoagulant therapy (antiplatelet therapy is allowed even if it will be temporary suspended before fiducials implant) * Platelets count \< 75'000/uL * Urethral stricture * Having received previous different salvage treatments for PCa local relapse * Development of BCR while on ADT * Concomitant inflammatory bowel disease or other serious systemic comorbidities * Presence of hip prosthesis * Impossibility of performing an MRI