Androgen Deprivation Therapy for Oligo-recurrent Prostate Cancer in Addition to radioTherapy

Inclusion criteria:

1. Histologically proven initial diagnosis of adenocarcinoma of the Prostate.
2. Biochemical recurrence of prostate cancer following primary local prostate treatment (radical prostatectomy, primary radiotherapy or radical prostatectomy +/- prostate bed adjuvant salvage radiotherapy) according to the EAU guidelines 2018. BCR after surgery: PSA \> 0.1ng/ml. BCR after radiotherapy: PSA nadir +2 ng/ml or 3 consequent rises in PSA level (after exclusion of possible bounce effect).
3. Minimal 1 lesion and maximum 4 lesions (bone + lymph nodes) in total, without evidence of visceral metastases.

   1. Nodal relapse (N1) in the pelvis on PSMA-PET/CT with a maximum of 4 positive lymph nodes. The upper limit of the pelvis is defined as the aortic bifurcation.
   2. Nodal relapse (M1a) on PSMA-PET/CT above the aortic bifurcation with a maximum of 3 positive lymph nodes.
   3. Bone relapse on PSMA-PET/CT with a maximum of 3 lesions.
   4. Combination of a, b, c with a maximum of 4 metastases.
4. Age \> 18 years.
5. Recent PSMA-PET/CT scan within 60 days prior to randomization.
6. PSA \< 10 ng/ml.
7. In case of chronic use of finasteride the PSA value should be \< 5 ng/ml.
8. WHO performance state 0-2.
9. Signed informed consent prior to registration/randomization.

Exclusion criteria

1. Visceral metastases.
2. PSA ≥ 10 ng/ml.
3. PSA-doubling time ≤ 3 months.
4. ADT or chemotherapy for recurrent PCa.
5. Testosterone \< 1.7 nmol/l
6. Painful metastases needed pain medication (\> level 1 pain medication) .
7. Invasive active cancers other than superficial non-melanoma skin cancers.
8. Inability or unwillingness to understand the information on trial-related topics, to give informed consent or to fill out QoL questionnaires.