Inclusion Criteria:  Histologically proven prostate cancer; cT2-4, partly determined by MRI; N1, determined by LND/SNP and/or PSMA PET/CT; iM0, determined by PSMA PET/CT; Accepted for curative intent treatment with EBRT of the prostate and regional nodes + 3y ADT; Visually PSMA-positive primary tumor and nodes, largest lesion ≥ average liver uptake; WHO performance score 0-1; Age > 18 years; For patients who have partners of childbearing potential: Willingness to use a method of birth control with adequate barrier protection during the study and for 6 months after the study drug administration; and Signed written informed consen  Exclusion Criteria:  Inability to comply to study procedures; Inability to adhere to radiation safety measures in hospital or at home; Inability to undergo the required biodistribution scans; Prior or current malignant disease with potential impact on treatment outcome or survival; Prior treatment with EBRT; Prior treatment with ADT, already initiated >1 month before the start of EBRT; Prior treatment with radionuclide therapies, 177Lu-PSMA-617 or other; Reduced bone marrow reserve (Hb<6 mmol/L, Leukocytes<2.5 10E9/L, or Platelets<100 10E9/L not older than 1 month before start of EBRT); Reduced renal function (GFR < 60 not older than 1 month before start of EBRT); Reduced salivary gland function (history of prior salivary gland disease); or Miction problems requiring pre-treatment with ADT.