Ni hao, since the spleen has gone down and the nodes are not continuing to grow, those are good signs and you can try not to worry too much. So then you probably have to just wait to see if things get worse or not.
The 3d ultrasound apparently did *not* show the bad sign of "loss of the hilum" in the neck nodes, which is very good news for you. Cancer causes "loss of the hilum". So then we can instead believe that the neck nodes grew probably because on some infection. Infection can also make the spleen grow temporarily larger.
You seem to be getting the best of care. You can ask why the doctor chose not to do a blood test called "PCR". There is probably a good reason why the PCR test is not a good option for you or for your subtype of lymphoma.
There might be some scar tissue (called fibrosis) in the neck nodes which makes them stay enlarged. The neck nodes are about at the maximum size where they can still be called 'reactive', which means not-cancer. If they grow noticeably larger then you should of course see the doctor again.
You can have another ultrasound in 3 months or 6 months. You would not want to have the radiation from another CT scan unless you really have to.
I hope you can not worry, which is probably not easy considering your history of lymphoma. But in general things are looking good for you. Good luck to you.
(Btw, I am able to understand your English very well.)
Thanks, Vichan. But I'm not a doctor.
Possibly the best advice on diet? That'd mostly involve eating anti-inflammatory foods and spices (like ginger) and avoiding pro-inflammatory foods. Also, body fat tends to make inflammatory chemicals, so it's better to be lean.
Then there are foods which might boost the immune system so it can kill cancer cells better. Unfortunately, there is no simple answer - this all would take more than a little research but it's worth it.
You should ask your doctor about the PCR test, maybe there is a good reason why that doesn't apply to you.
Good luck to you, Vichan! :)