Neoadjuvant Interstitial Brachytherapy Using Diffusing Alpha Emitters Radiation Therapy in Men With Prostate Cancer

Inclusion Criteria: * Pathologically confirmed, previously untreated, resectable prostate adenocarcinoma * Ability to provide tissue sample from the target or its vicinity, either from an archive or undergo another biopsy to provide a fresh sample * Medically fit for surgery * Targetable lesion must be technically amenable for complete coverage (including 3-5mm margins) by the DaRT seeds * Targetable lesion by either PSMA PET-CT according to PERCIST v1.0 OR by multiparametric MRI according RECIST v1.1 * Patients must be willing to undergo imaging before and after treatment with DaRT (prior to surgery) * Lesion size ≤ 3 cm in the longest diameter * Age ≥ 18 years old * ECOG Performance Status Scale ≤ 1 * Subjects' life expectancy is more than 6 months * WBC ≥ 3500/μl, granulocyte ≥ 1500/μl * Platelet count ≥ 100,000/μl * Calculated or measured creatinine clearance ≥ 60 cc/min * AST and ALT ≤ 2.5 X ULN * INR \<1.4 for patients not on Warfarin * Subjects are willing and able to sign an informed consent form Exclusion Criteria: * Documented evidence of distant metastases * Prior TURP or prostate surgery * Prior pelvic radiation * Any prior pelvic malignancy or other malignancy in the last 5 years, except for cured non-melanoma skin cancer * Inability to undergo MRI (i.e. permanent implanted device incompatible with MRI) * Known hypersensitivity to any of the components of the treatment. * Clinically significant cardiovascular disease, e.g. cardiac failure of New York Heart Association classes III-IV, uncontrolled coronary artery disease, cardiomyopathy, uncontrolled arrhythmia, uncontrolled hypertension, or history of myocardial infarction in the last 12 months. * Any medical or psychiatric illness which in the opinion of the investigator would compromise the patient's ability to tolerate this treatment or interfere with the study endpoints. * Patients must agree to use adequate contraception (vasectomy or barrier method of birth control) prior to study entry, for the duration of study participation and for 3 months after DaRT implant procedure * Volunteers participating in another interventional study in the past 30 days which might conflict with the endpoints of this study or the evaluation of response or toxicity of DaRT. * High probability of protocol non-compliance (in opinion of investigator) * Subjects not willing to sign an informed consent