Information about how to perform segmentation of CT in presence of pacemaker

Dear support,
I need to create a segmentation of thoracic tac in which a cardiac device (cardiac pacemaker) is placed.
I performed total segmentation with TotalSegmentation Extension but I obtained only the specific anatomical regions.
In a render view as CT-Muscle, I visualized the pacemaker, muscle and skin.
Which is the best way to also segment the muscle where the cardiac device will be positioned and the cardiac device too?
Is there a way to get the volume of a render like what you get from CT-Muscle rendering?