I finished 30 rounds of RT on July 8, 2019. I had 1 lymph node found with SCC but no extra-nodal extension. Same basic surgery as you. I asked my oncologist for the stats on recurrance with and without RT. The equivalent of roughly 600,000 chest X-rays (60 gray units) is significant and I was asking the same questions as you. I was given recurrance odds of 40% without and 20% with RT. My odds got “twice as good” so I did it. Everyone’s odds are different. This was based on my situation. Stage 4 tongue, clean margins, one node, no ENE, etc.

Surgery was intense recovery. I felt better almost daily. Recovery from RT is the opposite. It is a long slow recovery. I measure my recovery in weeks and months. The worst remaining side effect now, 7 months later, is stiffness in my neck and tongue and loss of saliva. I have lots of dental work required and must take extra steps to keep my teeth clean.

It’s simple discipline to address these items. I don’t mean easy to do. It’s hard but we do it because we must. Do my tongue exercises and brush, floss, rinse after every snack or meal. I mean it, every little cookie or bite. Change is tough after 52 years. I am back to full life many months ago. I surf, ski, run, work full time, and live with a giant smile every day. Thru this experience, my faith has deepened and offered me a joy and peace I never imagined before. I hope this helps you. Bless you and I pray you make a choice that feels right for you.