Radiation or not

I am post-op, a month ago I had a hysterectomy  for cervical cancer 1a2, for my two week fallow up my doctor said that the tumor that was removed was bigger than what they thought and I might need radiation if it was bigger than 1/5 of an inch.  My tumor was 3mm by 3.2mm before the surgery. I can not Imagine being much more. Does anyone know what is the cut off mesurement for not reciving anymore treatment after a hysterectomy?