Best Treatment Options/Suggestions

after a quick onset of jaundice; and haveing a stent inserted in bile duct; my dad was recently diagnosed at his local regional hospital with bile duct/liver cancer/cholangeocarcinoma w/ mass found on the liver and tested positive for malignant cancer cells in the lymph nodes. The doctor who did the biopsy said it's bad, he did not recommend doing surgery or chemotherapy and told him even w/surgery and chemo he would have 9 months at most 6 without doing anything. I am now tkaing him to sloan kettering and dana farber for second opinions. I have been doing a lot of research and finding that transplant, low dose chemo, immunotherapy and stem cell transplant seem to sound like domr of the best options as well as homepathic options and changing to a plant based diet. I'm also wondering if gamma knife surgery is an option for this type of cancer? Any thoughts/opinions/ideas or suggestions on hospitals, doctors or treatments is appreciated.