I too have an enlarged para-aortic lymph gland and 2 retro-peritoneal lymph glands (that means they're around the kidneys). And I know there's more but I haven't had my CT scans yet to determine where else) so we haven't discussed treatment yet except for chemo. But if radiation is the suggestion, I'd go for it.
Kidneys and liver lymph nodes (those pesky para-aortic lymph glands) must be popular spots. Who knows?

Colds don't cause lymph nodes at the back of your abdomen to be swollen. You can't stop lymph nodes from being swollen. I would go with what your oncologist recommends. If he recommended radiation I would do that.

I have an enlarged para aortic node that doctor is hoping will shrink with chemo but if not, she said we would zap it with radiation .

I am currently taking a chemo pill daily called Cytoxin and every three weeks get an immunotherapy treatment of Avastin and Keytruda. The treatment last an hour, but labs, a quick doctor visit, and all that takes it into 3 hours. CT scan two weeks ago says my bad lymph nodes are shrinking but now there is a development of a dark spot in my pancreas, Great HUH? So getting an endoscopy biopsy on Tuesday (happy halloween) to see what it is. I have been having bad tummy aches for about 2 months and now I now why. The doctor suggested taking pancreatic enzymes 3 x a day and WOW what a difference They really have helped my tum tum. Nice to have a doctor recommend something from a health food store that is legit. Cancer is quite a pain in the ass.

Are you on a cancer drug? If you are it will probably not move around, but if you are not,who knows. They have to examine it more I guess. I think radiation is a little dangerous. But maybe another type of drug for cancer. Certainly it would be good to get a second opinion from another doctor who has knowledge about such things. Not all chemo doctors do.