external beam radiation!!

Hello! everybody!
Well i just wanted to ask anybody, if they have been on external beam radiation, well i have already had three radiations my last was 4 months ago, I also had my limphnodes removed cause i had a reoccurance, my doctor found 7 tumors on my left side of my neck and 1 on my right, and all of them were papillary cancer and so again i got radiation about 4 months ago, but when i went to see her 2 moths ago she said something about external beam radiation, well my question is this, I want to know is this a normal procedure that they do or does it mean they did not get rid of all the cancer, has anybody been through this,will you please explain to me, and also what is it like when you get xtrnal beam rad. is it reallly bad, by the way I am 31 years old.I would really appreciate the information. thankyou! DELY