Some generic guidelines below for IMRT radiation treatments along with the acute and long term consequences depending on dosage and number of treatments.
Not sure how much Proton therapy differs and that was not available to me.
Having HPV P16 + Head and Neck cancer may require much less chemo and radiation than some cancer treatment centers are willing to admit as I can attest to.
Anyone could have their pos. or neg. cancer status checked during treatment with a blood test for this P16+ offered by Naveris labs its called the NavDx test. Medicare and the VA will cover the costs not sure about other insurers. $1,800 out of pocket
I would want to be tested before going over 50Gy worth of radiation and did get tested at 48 Gy. Test came back negative for cancer. A short pause in treatments of a couple weeks to get tested might be beneficial to possibly prevent further treatments and worsened long term toxicities.
Just my thoughts now that I've been through it.
The NavDx test may not be offered which it wasn't where I was treated but you can let your providers know you are aware of the test , request it and maybe get it worked into the schedule possibly preventing unnecessary treatments and some long term toxicities.

"Overview of IMRT in Head and Neck Cancer"
"Intensity-modulated radiation therapy (IMRT) is a sophisticated technique used to treat head and neck cancers. It allows for precise targeting of tumors while minimizing damage to surrounding healthy tissues.

Toxicity Comparison by Dose Ranges
The toxicity of IMRT can vary significantly based on the radiation dose administered. Below is a comparison of toxicity levels across different dose ranges:

Dose Range (Gy) Common Toxicities Observations
30-40 - Mild to moderate mucositis- Some dysphagia Generally well-tolerated with manageable side effects.
40-50 - Increased mucositis- Higher incidence of dysphagia- Risk of xerostomia More severe side effects; careful monitoring required.
50+ - Severe mucositis- Significant dysphagia- High risk of long-term xerostomia High toxicity levels; may require supportive care and interventions.
Key Considerations
Dose Escalation: Higher doses (above 50 Gy) can lead to increased toxicity, particularly affecting the mucosal lining and swallowing function.
Treatment Planning: IMRT allows for dose escalation while aiming to spare critical structures, but careful planning is essential to avoid excessive toxicity.
Patient Monitoring: Patients receiving higher doses should be closely monitored for acute and late toxicities, ensuring timely interventions.
Understanding these differences in toxicity is crucial for optimizing treatment plans and improving patient outcomes in head and neck cancer management".