DUET-study: A FEASIBILITY STUDY OF 177LU-PSMA RADIOLIGAND THERAPY ALTERNATED WITH RADIUM-223 IN PATIENTS WITH BONE-METASTATIC, OLIGO-METASTATIC HORMONE-SENSITIVE PROSTATE CANCER AFTER CURATIVE THERAPY.

Prior treatment

• Previous radioligand treatment
• Prior hip replacement surgery potentially influencing performance of PSMA PET/CT

Other illness

• Any medical condition that in the opinion of the investigator will negatively affect patients’ clinical status when participating in this trial
• Sjögrens syndrome
• A second active malignancy other than prostate cancer

Other

• A known subtype other than prostate adenocarcinoma
• Visceral (liver/lung) or brain metastases

• Histological proven adenocarcinoma of the prostate
• ECOG 0‐1
• Patients must have a life expectancy >12 months
• Laboratory values (at baseline within 4 weeks before start of therapy ): • White blood cells > 4.0 x 109/l • Platelet count > 150 x 109/l • Hemoglobin > 7.0 mmol/l • MDRD‐GFR ≥ 60 ml/min
• Signed informed consent.
• Previous curative therapy with a radical prostatectomy or external-beam radiotherapy (EBRT)
• Biochemical recurrence
• Serum PSA progression
• PSMA expressing metastases on an 18F‐PSMA‐PET‐CT scan: bone (and/or lymph node metastases) (miN1/miM1ab): minimally 1 bone metastases, maximally 5 bone metastases
• Local treatment for oligo‐metastases with radiotherapy or surgery appears to be no option anymore (due to prior treatment or the location of the metastatic lesions or if the patient refuses these treatments)
• No prior hormonal therapy (including any androgen directed treatment such as finasteride, dutasteride, bicalutamide, apalutamide, abiraterone, enzalutamide, and darolutamide) or taxane based chemotherapy (docetaxel or cabazitaxel)
• Testosterone > 1.7 nmol/l (at baseline within 4 weeks before start of therapy)
• A detectable lesion on the 18F‐PSMA PET/CT (at baseline within 4 weeks before start of therapy)