MR-guided Single-fraction SBRT for Nodal Oligorecurrent Prostate Cancer (PINPOINT)

This single-arm phase 2 trial investigates whether a single high-dose radiotherapy treatment can safely treat men whose prostate cancer has come back in a small number of lymph nodes in the pelvis or abdomen after curative treatment. Participants receive one fraction of 24 Gy delivered with MR-guided stereotactic body radiotherapy (SBRT), which uses MRI to visualise the tumour and surrounding organs during treatment. The main goal is to assess safety (severe side effects). The trial also evaluates local tumour control, longer-term side effects, time until hormone (androgen deprivation) therapy is needed, survival, and quality of life. The trial aims to enrol 48 patients.

Inclusion Criteria: Age ≥ 18 years Signed informed consent Histologically proven initial diagnosis of adenocarcinoma of the prostate ECOG performance status 0-2 Biochemical recurrence after curatively intended local treatment (radical prostatectomy and/or radiotherapy), with PSMA-PET/CT-verified nodal relapse in the pelvis or abdomen Any additional sites of disease beyond the protocol-specified target lymph nodes must be considered suitable for ablative treatment Life expectancy \> 6 months Lymph node size ≤ 2 cm Exclusion Criteria: Medical contraindications to MRI Inability to tolerate the physical set-up required for SABR Overlap between prior radiation fields and the current target area leading to high risk of clinically significant normal-tissue injury Contraindications to pelvic radiotherapy (chronic pelvic inflammatory bowel disease) Uncontrolled intercurrent illness