Trial of Ultrahypofractionated Focal Salvage Radiotherapy for Isolated Prostate Bed Recurrence After Radical Prostatectomy

Prior treatment

• Previous hematologic or primary solid malignancy within 3 years prior registration with the exception of curatively treated localized non-melanoma skin cancer
• Usage of products known to affect PSA levels within 4 weeks prior to start of trial treatment phase including any form of androgen suppression agents and androgen deprivation therapy
• Treatment with any experimental drug or participation within a clinical trial within 30 days prior to registration (exception: concurrent participation in the biobank studies is allowed)

Other

• Persistent PSA (\> 0.4 ng/mL) 4 to 20 weeks after RP
• Bilateral hip prosthesis
• Severe or active co-morbidity likely to impact on the advisability of SRT

• Written informed consent according to ICH/GCP (International Council for Harmonisation/Good Clinical Practice) regulations before registration and prior to any trial specific procedures
• Age ≥ 18 years at time of registration
• WHO performance status 0-1
• Lymph node negative adenocarcinoma of the prostate treated with radical prostatectomy (RP) at least 6 months before trial.Tumor stage pT2a-3b, R0-1, pN0 or cN0. according to the Union for International Cancer Control (UICC) TNM 2009.
• Evidence of measurable local recurrence at the prostate bed detected by PSMA PET/CT and mpMRI within the last 3 months. In case of unclear local recurrence, a biopsy confirmation is recommended.
• Patient must have non-metastatic (N0, M0) disease, as defined by a lack of nodal or distant metastases seen on PSMA PET/CT scan
• Patients must have non-castrate levels of serum testosterone (≥50 ng/dL).
• Patients must not have previously received hormonal therapy (LHRH agonists, antiandrogen, or both, or bilateral orchiectomy).
• Absence of any psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol and follow-up schedule; those conditions should be discussed with the patient before registration in the trial