PRIAPUS-PCa Study: Stereotactic Body Radiation Therapy (SBRT) and Androgen Deprivation Therapy (ADT) Impact on Sexual Function on Men With Unfavorable Intermediate Risk Prostate Cancer

Inclusion Criteria: * Men aged 18-80 years with biopsy-proven UIR-PCa (National Comprehensive Cancer Network \[NCCN\] criteria: Gleason score 7 (4+3), PSA 10-20 ng/mL, or clinical stage T2b-T2c) * Planned treatment with SBRT (36.25-37.5 Gy in 5 fractions) and ADT (6 months) * Baseline sexual function assessment available (International Index of Erectile Function \[IIEF-5, also known as SHIM\] score ≥ 12 or pre-selection erection status score of 1-3: erection insufficient for intercourse, sufficient but not optimal, or normal) * Eastern Cooperative Oncology Group (ECOG) performance status 0-1. * Written informed consent to participate. Exclusion Criteria: * Prior pelvic radiotherapy, prostate surgery, ADT, or chemotherapy * Pre-existing severe sexual dysfunction (IIEF-5 score \< 12 or pre-selection erection status score of 0: no erection) * Hypogonadism at presentation (baseline testosterone below normal range) * Contraindications to SBRT or ADT * Metastatic disease, second malignancy, or previous malignancies. * Benign or malignant penile diseases. * Use of medications altering ejaculation (e.g., 5-alpha reductase inhibitors) * Psychiatric conditions affecting questionnaire completion or QoL assessment * Severe comorbidities affecting QoL assessments (e.g., advanced cardiovascular disease).