Total radioactivity within VOI

Hello all,

I come to you for a question which I can’t find the answer on the forum or on internet.

I want to know the total radioactivity within a volume of interest. All quantitative tools I found for 3D slicer (PET-IndiC, Quantitative Indices, Quantitative Indices Tools, Label Statistics) do not seem to provide this information. Is there a solution ?

Thank you very much for your attention !