need an explanation for test result

My mother just had a PET/scan taken and the report is out. I don't have it with me, but my father told me the summary  of the report. It says: Mixed response with improvement in the primary LUL tumor but worsening of left pleural deposits.

We know she has lung cancer, and she has been taking Irresa for a few months. She has started discomfort when she breathes, so she just took another PET/scan to see if her tumor is worsening.

Does the summary of her report say that her tumor is getting worse? Or it offers an explanation of why she is having trouble breathing? Any idea is greatly appreciated.

[Dr Vinod]

Mixed response is the response to treatment is not very good. The Pleural deposits are worsening in the left side i.e there are more deposits and she is facing the consequences of breathing problems as her breathing capability is decreasing.

Positron emission tomography (PET) is a nuclear medicine imaging technique which produces a three-dimensional image or picture of functional processes in the body.

Take care!