The last thing you want on your senior travel tour is to get someplace so far off the beaten path that there isn't reasonable access to proper medical facilities, especially if you have a recurrent condition. Choose tours based in an area that has a modern hospital and leave the adventure to day trips from that location.
If you're intent on taking the road less traveled, scout out the area ahead of time so you know what medical facilities are available to you in case of an emergency. Make a list of these hospitals with addresses and phone numbers, and keep them with you at all times. If you have any special medical procedural needs, make sure the area you're visiting can accommodate you.