PRIMARY OBJECTIVE:~I. Proportion of metastatic castration resistant prostate cancer (mCRPC) patients with molecular and cellular alterations in tumor, immune and stromal cells after radioligand therapy assessed by histopathology/immunohistochemistry, ribonucleic acid (RNA)-sequencing and proteomic/phospho-proteomic analyses of biopsy samples.~SECONDARY OBJECTIVE:~I. Sequencing to identify frequently mutated genes.~OUTLINE:~Patients undergo an image-guided biopsy at baseline and 2-4 weeks after cycle 2 of 177Lu-PSMA-617 therapy.
This clinical trial studies mechanisms of resistance to 177-lutetium prostate specific membrane antigen (177Lu-PSMA) radioligand therapy using image-guided biopsies in patients with castrate-resistant prostate cancer that had spread to other places in the body (metastatic). Diagnostic procedures, such as image guided biopsies, may help in learning how well 177Lu-PSMA works to kill tumor cells and allow doctors to plan better treatment.