Nodal Radiation Therapy for Sentinel Lymph Node Positive Melanoma

Inclusion Criteria: * Must be planned for post-operative immunotherapy * No evidence of distant metastasis as determined by clinical examination and any form of imaging * No evidence of clinically involved lymph nodes prior to SLNB * Pathologically confirmed sentinel lymph node positive melanoma with high risk features (extracapsular extension \[ECE\] or 0.5 mm+ nodal tumor implant or 2+ involved nodes or lymphovascular invasion of the primary tumor) * Has provided written informed consent for participation in this trial * Eastern Cooperative Oncology Group (ECOG) performance status of 3 or less * Life expectancy greater than 6 months * Patients capable of childbearing are using adequate contraception * Available for follow-up Exclusion Criteria: * Complete lymph node dissection (CLND) of the nodal basin containing the positive SLN * Distant metastasis * Previous radiation therapy (RT) to the nodal area planned for RT such that the prior RT field would be included in the current treatment field. In other words, treatment on this trial would require re-irradiation of tissues * Women who are pregnant * Adults unable to consent, individuals who are not yet adults, pregnant women and prisoners will be excluded from this study