The patient to be enrolled in the prospective observational phase will be screened at first visit; prescription of Prostate Specific Antigen (PSA) and testosterone analysis, uroflowmetry and multiparametric Magnetic Resonance Imaging (mpMRI) are mandatory if not already done.
Additional staging imaging (computed tomography (CT) and/or bone scan) will be required according to National Comprehensive Cancer Network (NCCN) category risk group.
Subsequently, for the eligible patient, the enrollment phase involves eco-guided transrectal insertion of 3-4 gold fiducials in the prostate gland.
CT with full bladder and empty rectum will be done after 7-10 days from fiducials insertion; CyberKnife-Stereotactic Body Radiation Therapy (SBRT) treatment will start after 5-7 days from the simulation CT. A total of 36.25 Gy to the prostate gland will be executed in 5 alternate days. For each treatment delivery, the patient is required to be prepared in roughly the same bladder and rectum filling condition of the simulation day. Finally, in the last treatment day QoL and both clinician- and patient-reported genitourinary (GU) and gastrointestinal (GI) acute toxicity assessment is required.
