Plasmacytoma after radiation labs

I was diagnosed with a plasmacytoma that resulted in damage to my T10 vertebrae which has been surgically repaired. My back pain is gone. I had 23 radiation sessions ending eight weeks ago. I had new blood and urine labs a few days ago. All previous signs of blood or urine issues related to MM / Plasmacytoma were gone, but I now have traces of IgG Lambda < .1g/dl where before I had IgG kappa at .1g/dl? I am searching for understanding of this change. My bone marrow did not show measurable levels of monoclonal proteins, so I am hoping that at this point all issues as with the plasmacytoma. I am 71 and generally in good health. Slight anemia after radiation