This phase I/II trial studies the side effects and best dose of a combination of gabapentin and ketamine and to see how well it works to prevent acute and chronic pain in patients receiving chemotherapy and radiation therapy (chemoradiation) for head and neck cancer that has spread to nearby tissue or lymph nodes (locally advanced). Gabapentin is a medication that is commonly used to treat nerve related pain. Specifically, it has been used to treat pain involving the mouth, throat and nasal passages in head and neck cancer patients treated with radiation. Ketamine is a type of general anesthetic that blocks pathways to the brain involved with sensing pain. This trial may help doctors determine how patients tolerate the combination of gabapentin and ketamine and to find the correct dosing for ketamine in those taking gabapentin. This will be the basis for a future, larger study to look at how effective this combination is at reducing and/or preventing pain in head and neck cancer patients.

The goal of this clinical trial is to test a new drug plus standard treatment compared with
standard treatment alone in patients with advanced head and neck squamous cell carcinoma and
cholangiocarcinoma.

The main questions it aims to answer are:

- is the new drug plus standard treatment safe and tolerable

- is the new drug plus standard treatment more effective than standard treatment

To compare the effectiveness of an APCD to Usual Care in the management of lymphedema and
fibrosis (LEF) in head and neck cancer (HNC) survivors.

This phase II trial tests whether reduced dose radiation therapy after transoral robotic surgery works in treating patients with human papillomavirus (HPV)-positive oropharyngeal cancer. HPV positive oropharyngeal cancer has a better prognosis than oropharyngeal cancer not caused by HPV. A standard of care treatment for HPV positive oropharyngeal cancer is transoral robotic surgery followed by radiation therapy. However, this treatment is associated with many long-term side effects including difficulty swallowing. Radiation therapy uses high energy rays to kill tumor cells and shrink tumors. Giving reduced dose radiation therapy after transoral robotic surgery may improve swallowing outcomes and quality of life compared to standard of care dose radiation therapy after transoral robotic surgery.