So sorry to hear. This is a longshot, but I recently spoke with a relative who is being treated at U of Iowa research hospital. After chemo and radiation, Drs there said they were out of options. She looked into alternative therapy and was directed to Aretsunate, an oral anti malaria drug. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9406496/#:~:text=The%20antitumor%20effects%20of%20artesunate,manner%20(Figure%201B).
After several months, her petscan was clean. Drs are hesitant to say the drug was effective. But her nurse practitioner was very optimistic.
She also used a Rife mat https://www.cancerresearchuk.org/about-cancer/treatment/complementary-alternative-therapies/individual-therapies/rife-machine-and-cancer

She exhausted conventional therapies, so she was willing to try the alternative, and has had a positive outcome. I will add that she is a Christian with deep faith, and believes God brought healing through prayer and these alternatives.
I will pray for you both.