Has anyone dealt with cancer in the gingiva (gums), upper back? What to expect?

I was wondering if anyone had cancer in the upper jaw, at or near the back molars? My surgeon extracted 3 molars and the canine tooth on the left side. Although I had surgery at the end of June, the post-op pathology report is not back, but he said that since there was some bone involvement, the tumor board would probably recommends RADs. I'm curious if RADS that is focused on the upper back of the mouth would have the same side effects from the RADS. When I asked my surgeon this question, he was a bit dismissive. He said the swallowing and other problems I mentioned were more common in tongue or throat cancer or the lower part of the mouth, and when he thought I was giving him a look like I wasn't buying what he said, he told me had been doing this a long time and would know better than me. How spread out from the location of the removed tumor will the side effects reach?