Unfortunately Pam lymphedema is a fact of life for us cancer survivors. The therapy is good because it teaches you how to help massage the area yourself to help releave the fluid build up. If the massage techniques aren't enough, I say see your doctor to get a referral for a prosthetic company (like Hanger, I know they order sleeves) and go get fitted for a sleeve. Once you get your sleeve, do no sleep in it and make sure you always have it with you to fly.
And if you are still having problems (like I did) ask your oncologist to rx you a pnuematic sleeve/pump (it would likely be mailed to you, and is considered home medical equip.)
I used the sleeve for 1 hour every day for about 3 mo, and I haven't suffered any major problems since - and I suffered horrible pain and swelling (I called my arm a wing, it hung so low!) for about 8 mos. before I got my machine. Most days you would find me holding my arm raised above my head to try to help with the fluids.
Now I have mine under control and I beleive you can too, it just takes some time!