Linda, I was Stage II and had radiation recommended because of perineural and perivascular invasion. That means that the tumor was growing around or right next to a nerve (perineural) and that blood vessels were in it (pervascular) and both those things are of concern because cancer cells travel from one spot to another through the blood and also through the nervous system, so it puts you at a slightly higher risk of having a recurrence because of those things. That's why radiation is needed. Or this is my udnderstanding.

It's a good question about where they will radiate when there's no cancer left that can be seen. They radiate focsing on the most likely spots for recurrence, the site where the original tumor was and lymph pathways down the neck among others. Some patients who post here have been told that they should not have IMRT under these circumstances, since there is no cancer to focus on but when I was geting opinions on treatment (2 and 1/2 years ago now), I was told that IMRT can still be used and they just radiate focusing more on the places where the cancer would be most likely to spread.

I hope this helps.

Nelie