I started radiation about day 48 after my surgery. I don't remember the exact timeframe but most protocols like for you to start no later than 50 days after surgery. The sooner you start the better your outcome so to speak. Of course they want you to heal from the surgery as much as possible prior to the radiation but start as soon as possible. I had 2 cancerous lymph nodes out of 35 or so. 3cm base of tongue tumor. Your Stage level should help determine your treatment protocol.
Even though I had clear margins there was a chance a few cancer cells remained as the Doctor put it. So he highly suggested radiation. However, The only radiation I was going to get was Proton as much less invasion. He wanted 60Gy (30 Rounds) . Each session lasted 30 minutes bolted to a table inside the "tunnel". They treated 3 places so it took longer. The tumor bed and Both sides of the neck even though one had no lymph node cancer . I wanted much less as I was reading about new De-escalation trails. He stood firm on the 30 rounds so that is what I did. A good Oncology doctor that treats throat cancer for a living knows more than both of us and generally want the best outcome for their patients. Looking back should I have insisted on less rounds ? Not sure. I stand here today with very few side effects, I am cancer free and Alive.
I did have a tough time speaking for 6-9 months. Gradually improved little by little. Hoarse some days, nasal voice some days. Faint voice some days. Some days almost normal voice. Alot depends on mucous build up which gets better over many months. My lymphoma remains in check. I hope I answered your questions. God Speed!