I haven't had nasal congestion from chemo and radiation but I've had it from the aromatase inhibitor (letrozole). I use an anti-histamine and a saline nasal spray. I tried a medicated nasal spray but it caused nose bleeds. Good luck!

Me as well!
Although it was not from the allege, the medicine worked well after several doctor's visit.
Luck...

Talk to your gen. doctor...I had a cough and stuffed up. I was instructed to use overthecounter medicated nasal spray at night ... saline during the day and overthecounter allery med. It worked. However each person is unique.