Hi Robin...
I'm sorry to hear about your sister's diagnosis, but she is fortunate to have you as an advocate for her care...
Remember, I am NOT a Dr or lawyer, so take my words only as friendly information to support you and your sister's relationship with her health care professionals.
Amifostene has VERY serious potential side effects, and depending on stage, cell differentiation, location; dose, type and duration of radiation...it may not be worth the risks.
As far as PEG, my understanding is that the weight loss threashold is around 10% overall body loss to trigger a PEG, although mine and others are done "just in case".
I don't know enough about the mouth sore meds you are thinking about, but in general, discussing meds far in advance of their need is always intelligent health care planning.
To me it sounds like she is weathering the radiation well, but you are right to be concerned about her care...
Regardless of the health care professionals' motivations,(even if they were Mother Theresa, working for FREE), medical personnel are just as susceptible to human flaws as any of us...
They might be tired, distracted, or financially motivated in ways that affect their patients' care...
I had one at an early consult continually look at his watch, and I asked: "Are you pressed for time?", and he said, "Well, Yes, actually, I have a job interview in an hour..."
Most likely, they don't even know the true nature of your Sister's insurance details, maybe just that she doesn't have group care, but they might not know dozens of other factors that affect her ability to pay, not pay, or tap into the hundreds of 3rd party sources for subsidy.
I think that your concern is one of the reasons I decided to seek care under a CCC since their shear size dillutes ONE person's ability to make care decisions based on ability or inability to pay.
Truth is, even with the BEST INSURANCE in the world today, Drs and hospitals are far from assured of payments of their exhorbinent charges.
Insurance companies deny, deny, deny, then delay, delay, delay.
That is their MO. Also, if a care provider (and certainly most any hospital) has a contract with a particular insurance company to be a PPO provider, then they get usually a fraction of the total billed for almost any proceedure, medicine or charge...
So, providers bill outrageous rates sometimes knowing that insurance adjusters are going to pay a percentage (mostly based on preestablished contract charges for certain proceedures, etc).
(sometimes unethically used as a nice tax write-off of "losses" for billed services never paid in full)
This in turn makes insurance companies scrutinize their bills (bill review), which in turn makes providers bill more, and as you can see, this is just one tiny part of our terribly flawed medical system.
But, it's still the best in the world.
The only way to ensure the premium best treatment is to be filty rich and/or famous, and even then, it may only be a marginal motivation for any one health care provider in particular.
I realize this is WAY MORE than you asked, and truth is, you can find dozens of entire books written on your topic alone.
Bottom line, you (and most importantly your Sister), need to be able to trust your health care provider(s)...Some sketicism and questioning is VERY healthy, (I believe), and the leader's in their fields usually appreciate this, but it boils down to the relationship you have with someone whom you (or in this case your Sister) trust with one's life.
Most of the people I've met (and I've met dozens in the last 3 months), have been caring, compassionate, intelligent and hard working professionals who have literally dedicated their entire adult lives to fighting this disease.
I think a lot of the loosers are automatically filtered out by the process and naturally go on to other fields.
Sorry to ramble...Guess it's all the vitamins I took (OH, Don't get me started on Vitamins!) :-)