Escalating Cycle 1 Dose of Lu-177-PSMA-617 for the Treatment of Metastatic Castration Resistant Prostate Cancer

Inclusion Criteria: * Patients must be eligible for standard Lu-177-PSMA617 RLT for mCRPC, including PSMA PET/CT scan positive (lesion uptake \> liver uptake by visual assessment) * Patients must have recovered to ≤ Grade 2 from all clinically significant toxicities related to prior therapies (i.e., prior chemotherapy, external beam radiation, brachytherapy, immunotherapy, etc.) * Patients must be ≥18 years of age * Patients must have an ECOG performance status of 0 or 1 * Absolute neutrophil count (ANC) ≥ 1500/mm\^3 * Platelet count ≥ 150,000/mm\^3 * Hemoglobin ≥ 10.0 g/dL * Estimated glomerular filtration rate (EGFR) ≥ 60ml/min * Bilirubin ≤ 1.5 x the institutional upper limit of normal (ULN). For patients with known Gilbert's Syndrome ≤ 3 x ULN is permitted * Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≤ 3.0 x ULN OR ≤ 5.0 x ULN for patients with liver metastases * Albumin \> 3.0 g/dL * Use effective birth control methods during the treatment and for 14 weeks after the last Lu-177-PSMA-617 dose * Ability to understand and the willingness to sign a written informed consent Exclusion Criteria: * Does not meet criteria for standard Lu-177-PSMA-617 RLT * Diffuse marrow involvement evident on Ga-68-PSMA PET/CT as assessed by study treating clinician * Prior RLT * Unmanageable concurrent bladder outflow obstruction or urinary incontinence * Concurrent serious (as determined by the Principal Investigator) medical conditions, including, but not limited to, New York Heart Association class III or IV congestive heart failure, history of congenital prolonged QT syndrome, uncontrolled infection, active hepatitis B or C, or other significant co-morbid conditions that in the opinion of the investigator would impair study participation or cooperation * Plan to start any additional anti-cancer therapy or investigational agents during study therapy. Anti-cancer therapies include chemotherapy and endocrine therapy * Exclusion criteria for participation in other investigational trials: should not participate during RLT or 30 days prior to start of RLT