It looks as though your husband is in the same issue I went through which started in October of 2023. After the radiation and chemo, I was advised of the next steps. The negativity of the Oncologist I was seeing immediately made me get a 2nd opinion. I am so glad I did.
The next treatment was 5 days a month for 6 months of taking the same chemo pills but with the highest dose I could. I was done in July of 2024. The only medication I take now is seizure pills as that is what happened when this was discovered.
Early 2025, my oncologist said there was growth again. She had a wait and see attitude, thank God! My last MRI in early August of this year, the oncologist said just as she suspected, the growth shrunk.
As a side note, due to my original diagnosis which gave me a condition for that of a 5 year old, my oncologist had my blood work sent to the lab again. The 2nd opinion came back with a diagnosis that was different than the first one which I looked up and it pretty much has this as the answer 🤷‍♀️ why I had this happen is unknown.
Sending prayers and hugs that your husband has good results like I have experienced.
Sjt