I am having a ct scan for a nodule on my rib. if it is cancer do they do surgery and or meds to remove? or just watch it?

Depends: If actually a tumor of bone/muscle that started in rib, they would remove as long as it hadnt spread elsewhere. That is an uncommon place for a tumor to start, but does happen. If a tumor that spread to rib, then they would find source of tumor and treat based on where it started. That is more common. However, many imaging findings are benign, so i important to have it worked up properly first.

Depends+: I am not sure if the "nodule" is actually in the rib or in the soft tissue just outside the rib. A soft tissue lesion can be a lipoma which if small and asymptomatic may be ignored or watched but if something else may be treated (surgery or meds depending on what it is). If lesion is in the rib, treatment also depends on if it's benign or not.