The one thing you need to focus on above all else is transparency and preventing scams. Video of the actual person who needs the treatment would go a long way, as would video updates along the way. I'm thinking an Android app that the locals could use to document the process.
If you solve that properly, this will really take off and do a lot of good.
Also, you're going to eventually need to take a very small cut of the donations to pay living expenses for your volunteers. 100% to the patient sounds great, but for my donation, I'd prefer to know that there is someone dedicated full-time to the cause and overseeing the process, and receiving a reasonable salary for it. Of course, be 100% transparent about those salaries as well.
If you solve that properly, this will really take off and do a lot of good.
Also, you're going to eventually need to take a very small cut of the donations to pay living expenses for your volunteers. 100% to the patient sounds great, but for my donation, I'd prefer to know that there is someone dedicated full-time to the cause and overseeing the process, and receiving a reasonable salary for it. Of course, be 100% transparent about those salaries as well.