Post Surgery/Clean PET - recommended radiation treatment?

Hi,

Just to be clear, I am not asking about whether she should do radiation - she will, but what kind, and if anyone has a big problem with a somehwat short delay?

My fiancee got oral cancer again (12 years after vanquishing it from her tongue the first time - this time in the mandible/tongue/part of throat) stage 4 and and had flap surgery to remove the tumor and replace from bone and tissue from leg.  Three months later her first PET scan is clean!

 Now doctors are recommending radiation.  Those with a proton machine recommend proton.  Those without proton recommend traditional radiation. I get that they want to kill any remaining cancer cells that cannot now be detected.

Questions:

Does anyone have opinions from their experience on which way to go when there is no tumor?  They are making their best judgments as to where it is most likely to come back as the target.

Can anyone share their experience when getting proton radiation when there is no tumor?

So the literature talks about how targeted it is to not flow through the irradiated site, but stop at the targeted area.  But there are sores, and people report losing hair.  Are those side effects from the entry?  Or is there still some exit burning?

On the delay.  Surgery was in May 2017.  The clean PET (the first post-surgical scan) was in August 2017 (nothing lit up on the scan!)  We have a wedding planned for 9/22 and a honeymoon until October 4.  It is 4 years since I lost my first wife to breast cancer.  My fiancee has never been married (we are both 50 years old).  We understand that it can take weeks for insurance to approve proton radiation (putting it past the honeymoon).  With either radiation, she can get staged and some kind of mask designed and made before/during the wedding and honeymoon so she can start as soon as we get back. We could delay the wedding (and give 150 guests a rain check) if they want to start ASAP, but it seems that at this point they would not be ready to radiate anyway until the week or so before the wedding, so that delay would only be about 2 or 3 weeks.  But it has already been three months now since surgery, and we will be back from our honeymoon in just over 6 more weeks.  Any thoughts on whether this wait is reasonable or not? Most doctors we talk to think it is a reasonable balance with quality of life.  i'm looking for either support for this decision or a damn good reason to move the whole celebration (OK - I understand the "to prevent death" do it sooner because you just don't know part of the equation.)  But if you dont know, how to judge if a little more delay will affect the impact?)

Anything else I should learn about?

Thank you!  I did not find any posts about this circumstance here (no detectable cancer now) or recent comments on proton radiation.