How would you manage locally advanced head and neck patients getting definitive chemoradiation who show progression halfway through treatment?

I have seen this twice within the last year. Here is what we did:

1) First patient had high risk cutaneous SCC s/p WLE and neck dissection. He progressed in the skin after surgery when seen for sim, and continued to progress during first week of RT. We stopped RT, started cemiplimab. He had a remark...

This is a very unusual event. Make sure it’s real. Step on the gas and accelerate/hyperfractionate.