Chemotherapy is the use of medicine to destroy cancer cells. Chemotherapy is called a systemic treatment because the medicines enter the bloodstream, travel through the body, and can destroy cancer cells outside the target area.
Chemotherapy may be taken by mouth (orally), or it may be given through a needle into a vein (intravenously, or IV) or a muscle (intramuscular, or IM). It also may be given through a catheter directly into the abdominal cavity. This is called intraperitoneal chemotherapy. Or it may be given directly into an organ, such as the bladder. This is called intravesical chemotherapy.
WebMD Medical Reference from Healthwise