Aldesleukin Imaging in Viewing Tumor Growth in Patients With Stage IV Melanoma Receiving Ipilimumab or Pembrolizumab Therapy

PRIMARY OBJECTIVES: I. Feasibility/biodistribution of 99mTc-HYNIC-IL2 (technetium Tc 99 hydrazinonicotinamide-tricine-linked interleukin 2) scintigraphy in patients with metastatic melanoma undergoing immunotherapy with either ipilimumab (commercial source) or pembrolizumab. SECONDARY OBJECTIVES: I. Correlation of tumor infiltrating lymphocyte (TIL) invasion (scintigraphy/histology) with tumor burden; and description of any clinical side effects associated with imaging. TERTIARY OBJECTIVES: I. Correlation of TIL invasion assessed by 99mTc-HYNIC-IL2 scintigraphy vs. histology (total and subsets of TIL), as well as screen for peripheral blood correlates. OUTLINE: Patients are assigned to 1 of 2 groups. COHORT I: Patients undergo technetium Tc 99 hydrazinonicotinamide-tricine-linked interleukin-2 scintigraphy prior to receiving ipilimumab or pembrolizumab and at 12 weeks. COHORT II: Patients undergo technetium Tc 99 hydrazinonicotinamide-tricine-linked interleukin-2 scintigraphy prior to receiving ipilimumab or pembrolizumab, at 3-4 weeks, and at 12 weeks. After completion of study treatment, patients are followed up at 30-45 days.