New scan could spot hidden cancer spread

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria for Urothelial Carcinoma Cohort: * Patients with histologically confirmed metastatic urothelial carcinoma with extrapelvic nodal and/or visceral sites of disease (including lung, liver, bone, or soft tissue) * At least 1 lesion assessable by FDG PET/CT according to RECIST and PERCIST guidelines where applicable, that are determined suspicious for metastasis by an MSKCC attending radiologist or nuclear medicine physician. * Karnofsky performance status ≥50% (or ECOG/WHO ≤2) * Participant is ≥18 years of age * Patient must be able to understand and is willing to sign a written informed consent document Inclusion Criteria for Melanoma Cohort: * Patients with histologically confirmed metastatic melanoma * At least 1 metastatic lesion assessable by CT or FDG PET/CT according to RECIST that is determined to be suspicious for metastasis by an MSKCC attending radiologist or nuclear medicine physician * ECOG \<= 2 * Participant is \>= 18 years of age * Patient must be able to understand and is willing to sign a written informed consent document Exclusion Criteria for Urothelial Carcinoma Cohort: * Patients with pelvic node-only metastatic disease. If the patient has lymph node only disease, at least one PET-assessable node must be located outside of the pelvis * Patients with bone only disease * Unable to lie flat, still, or to tolerate a PET scan * Patient undergoing active treatment for non-urothelial malignancy, other than skin basal cell or cutaneous superficial squamous cell carcinoma that has not metastasized. * Patients on a therapeutic clinical trial where PSMA imaging would interfere with the conduct of the trial * Patients undergoing active surveillance with a known history of non-urothelial malignancies * Women who are pregnant. All women of childbearing potential must have a documented negative pregnancy test. Exclusion Criteria for Melanoma Cohort: * Unable to lie flat, still, or tolerate PET scan. * Patient is on another therapeutic trial where PSMA imaging would interfere with the conduct of the trial. * Women who are pregnant. All women of childbearing potential must have a documented negative pregnancy test.