Possible mets to lungs ?

Hi all, am new to this site, but not new to my husbands cancer and treatment. Condense version is stage IV colon cancer with mets to liver on diagnosis. This from a routine screening colonoscopy 3 years ago. Now a new concern.

Colon resection, chemo to shrink the liver mets, two staged liver resection so the liver could regenerate more tissue between surgeries. More chemo.
Apearance of a new tumor on the liver, RFA ablation, and the new and different chemo.

All through this they always said, there are these findings in the lungs, but they aren't changing, we will continue to watch them. And my husband has had one type of scan or another every 3 months. Including brain scans as he developed some changes from the chemo,

On this weeks scans the lung findings did change. They were referred to as nodules,and when I asked how many the answer was "innumerable".
The oncologist says they can't be biopsied at this point and every scan has been done. And will I to follow w another scan in 3 months.

So,,,here's the real question. The doctor says its possible that this is inflammatory in nature. He is a top dog in a major hospital in a major city and I don't doubt his approach. Has anyone ever had findings like these that were NOT lung mets. My husband has been through so much , soldiers on, but won't talk about any this. It just seems pretty dire to me,,,and there is a question of whether his brain can take more chemo because of what has happened with his "posterior encephalopathy".

Grateful for any feedback, info. I am so tired.

Maureen