Hi,
There is a website nccn.org (the National Comprehensive Cancer Network) that gives guidelines on treatments. You do have to register, which is free, & then you can look at them. On the left side you'll find NCCN guidelines, go into that, then cancer by site, head and neck, and when there go to page 17 for cancers of the oral cavity. You can see that the preferred treatment is resection (surgery) of lesion and neck dissection for this particular kind of oral cancer. Then if no adverse features, radiation is optional, adverse features, then it gives you radiation and perhaps chemo.

It would be very hard to be in your situation with a parent who is fragile. The treatment is not easy, but there are older persons who go through it. Christine provided the link to the CCCs, and I too would suggest you get a second opinion from one of them.

Best,
Anne