Image-guided Focal Dose Escalation- Primary pc Treated With Primary External Beam Hypofract.Stereotactic rt

Inclusion Criteria: 1. Histologically confirmed adenocarcinoma of the prostate (histological confirmation can be based on tissue taken at any time, but a re-biopsy should be considered if the biopsy is more than 12 months old) 2. Primary localized PCa (cN0 and cM0 in mpMRI and PSMA PET): * high- or very high-risk according to NCCN v2.2021 (see 20.3) OR * unfavorable intermediate-risk disease according to NCCN v2.2021 (see 20.3) 3. Signed, written informed consent for HypoFocal-SBRT study 4. Age \> 18 years 5. Previously conducted PSMA-PET/CT and mpMRI scans or PSMA-PET/MR, fulfilling standard requirements for PCa (see also 6.5) 6. ECOG Performance score 0 or 1 7. IPSS Score ≤15 8. Prostate volume ≤75 ml at RT planning Exclusion Criteria: 1. Evidence of neuroendocrine tumor cells 2. Prior radiotherapy to the prostate or pelvis 3. Prior radical prostatectomy 4. Prior focal therapy approaches to the prostate 5. Time gap between the beginning of ADT and conduction of mpMRI and PSMA PET scans is \>1 month 6. Radiologically suspicious or pathologically confirmed lymph node involvement (cN+) in mpMRI and/or PSMA PET/CT 7. Evidence of metastatic disease (cM+) in mpMRI and/or PSMA PET/CT 8. Evidence of cT4 disease in mpMRI or PSMA PET/CT 9. PSA \>30 ng/ml prior to starting ADT 10. Expected patient survival \<5 years 11. Bilateral hip prostheses or any other implants/hardware that would introduce substantial CT artefacts 12. Contraindication to undergo a mpMRI scan 13. Prostate surgery (TURP or HOLEP) with a significant tissue cavity or prostate surgery (TURP or HOLEP) within the last 6 months prior to randomization 14. Medical conditions likely to make radiotherapy inadvisable e.g. acute inflammatory bowel disease, hemiplegia or paraplegia 15. Previous malignancy within the last 2 years (except basal cell carcinoma or squamous cell carcinoma of the skin), or if previous malignancy is expected to significantly compromise 5 year survival 16. Any other contraindication to external beam radiotherapy (EBRT) to the pelvis 17. In mpMRI and PSMA PET/CT or PSMA PET/MRI scans no visible tumor 18. Participation in any other interventional clinical trial within the last 30 days before the start of this trial 19. Simultaneous participation in other interventional trials which could interfere with this trial; simultaneous participation in registry and diagnostic trials is allowed 20. Patient without legal capacity who is unable to understand the nature, significance and consequences of the trial; 21. Known or persistent abuse of medication, drugs or alcohol 22. Patients expected to have severe set up problems 23. Dose constraints for organs at risk cannot be adhered to