Use of the see-thru dressings sounds like the best approach. A letter from the MD, for CYA purposes should anything go south, is also a good idea.

I've also had to assist with air travel for a family member w/PICC a line, but it was prior to the radiation box / prison-style friskings. Thankfully TSA knew what the PICC line was and we had no problems.

1) It probably wouldn't hurt to call PBI airport public relations and politely request if an airport employee could assist at the TSA checkpoint -- or contact the TSA at PBI and arrange in advance for a Supervisor to meet you and accompany you & parents via the checkpoint.

2) Do you have any friends / contacts in SoFla who are law enforcement / peace officers that might be able to accompany you and your parents through TSA?

On another occasion, I arranged to have a friend of family who was a sheriff deputy accompany a grandparent (multiple medical problems including dementia) through a TSA checkpoint in central Florida. This sheriff deputy was from a county just outside of where the airport was located, but accompanied us from the medical facility all the way to and through the airport.

Best of luck to you and a quick recovery for your father!