Have you considered a second opinion? I was diagnosed with an aggressive type of endometrial cancer and went for both a second & a third opinion. All 3 doctors, with their grim faces & serious tone, suggested the same treatment plan - surgery, chemotherapy, external beam radiation, and brachytherapy - everything but drinking bleach 😉. I did it all and I’m here 3 years post treatment. No regrets, despite some manageable GI & bladder issues and the need to use a dilator because of the brachytherapy’s side effect of vaginal stenosis. The radiation oncologist should provide your wife with the rundown of possible side effects. Post her questions here as well, as the women here will be forthright.
Best wishes. You are a wonderfully supportive spouse.