I have seen some T1 patients have chemoradiation, just radiation, including myself, and it depends on the doctor, institution, tumor size, thickness, area of primary, nodal involvement, patient. NCCN is just a guideline.

BOT can be persistent tumor, more difficult to treat, due to the deep musculature, lymphatics in the area for tumor to spread, go deeper in the BOT. Was chemoradiation offered or just a question?

I have a long history with T1 tonsil confirmed by biopsy, possibly BOT, valeculla involvement by PET, but not found in tissue sample. Was scheduled for Induction Chemo, followed by concurrent chemo radiation, but reaction to IC prevented that. 5 days IC killed the tonsil cancer, but it returned, as I later read would happen in less than a year. Anyway, had 4 more recurrences after that went into my neck muscle, skin, outside of primary and lymphs somehow to be "free form" or "roaming cancer" in my neck that can spread anywhere. Had positive margins from one surgery, Perineural and lymphovasvular invasion, so cancer can travel anywhere along the blood and veins lines too, and needed a number of treatments, radiation, surgeries. i have been continuously in some form of CRT treatment, recovery, surgery, dental, HBO, transfusions for 3.5 years for an original T1N2bMO.