This phase II trial studies how well personalized neck radiation therapy directed by sentinel lymph node biopsy (SLNB) works in treating patients with oral cavity squamous cell carcinoma (OCSCC). SLNB can be performed as part of standard care for OCSCC. During SLNB, a radiotracer is injected around the tumor. The lymph nodes are then biopsied and tested to see if the tracer injected into the tumor traveled to and is present in the sentinel lymph nodes (SLNs). Results of the SLNB are used to determine whether lymph nodes should be removed in both sides of the neck or just on the same side as the primary tumor. Standard treatment then involves radiation therapy to both sides of the neck, regardless of SLNB results. Radiation therapy uses high energy x-rays, particles, or radioactive seeds to kill tumor cells and shrink tumors. Studies have shown only a small number of patients develop a return of the cancer (recurrence) in the opposite side of the neck after radiation therapy. In addition, radiation therapy can negatively impact patient outcomes like saliva production, speech and swallow function, increased risk of radiation induced cancers, and chronic pain. Standard of care SLNBs may be effective in determining whether radiation therapy only needs to be administered to one side of the neck or both sides. This may help spare tissue on the opposite side of the neck from receiving radiation if there is no indication of lymph node involvement there.