Radiomics features for two combined structures

Hi,

I am using Pyradiomics to extract features from whole body PET/CT, and I have a question about combing two structures. For example, I separate the whole/body structure into two parts: upper body and lower body, and then exact features for each structure respectively.

My question is: Is it possible to generate another metric for the two structures combined (whole body) based on the results of the two structures separately without having to run it again using whole body structure?

Thanks for any comments!

Operating system: Windows
Slicer version:
Expected behavior:
Actual behavior: