Not everyone is effected by oral routes and it has to do with genetics and liver enzyme expression. Others bias towards 10 hydroxy and trivial doses push them into psychosis. It is entirely possible that you and your father are at different ends of the spectrum as far as dose/response.
I've been where you are and having realistic expectations lets you use the time you have best. RSO or anything pot derived is not going to help his prognosis. If it was a matter of treating pain or side effects from chemo then that is one thing but the real medical uses of pot as an actual treatment is limited to certain types of seizures in children using CBD. Thats it. It is the ONLY thing that is an actual proven medical use as a treatment rather than a palliative. I know it is touted as a magical cure for everything but that is simply bullshit and it is important to accept that. While it is tempting to grasp at anything that can offer hope, it may distract you from actual therapeutics. There are things out there that have real effects and may prolong his life or allow him to retain a good quality of life for the time he has left.
Ask his doc for cell line culturing and a treatment test array against those cells. It is a technique for picking drugs that is very rarely used but is an extremely powerful tool for choosing the path with the best outcome. It isn't particularly expensive but it does take a few weeks to complete. If that doesn't pan out with anything promising, you might want to ask about taxol and then flipping to colchicine once the tumors start to grow again. He'll want to puke his bones out during the flip but both of them will give him more quality time during the main sequence of their use.
Good luck
-Eskander
