How fast can treatment make a sarcoma go away, if the ct scan turns out to be sarcoma?

Depends: Sarcoma is a cancer of the soft tissues, usually muscle, bone, and/or fat. Treatment will vary on each individual patient with consideration for tumor size/location and cell type. It can involve surgery followed by chemotherapy or chemotherapy alone.

Hours to lifetime: Most sarcomas require surgery, so the few hours it takes to do the surgery will make the sarcoma go away. Some require chemotherapy and/or radiation. Chemo usually takes 6 months to a year; radiation about 6 weeks. There is always risk of recurrence or metastasis, so long term follow up is mandatory. More treatment may be needed if sarcoma recurs or spreads.