I have a regular cleaning out (nose scope) done about every 2 mos...more if I am feeling full. With that being said, they can only reach a certain area of the sinuses with this type of removal. When I had the CT scan done...it showed that all my sinus cavities were so full there was no air at all in them. I can understand the scare about the cancer risk, but I have had so many X-rays, CT scans, and MRIs done that I should be glowing. After my first surgery, I felt so much better...and it lasted for several years before I needed another one. Unfortunately, chronic sinusitis is hard to "fix". I recommend the CT scan to see how full his sinuses are. Good Luck!