Ablation refers to treatments that destroy cancer tumors without removing them, most commonly used in the liver. These techniques are often used in patients with no more than a few small tumors but for whom surgery is not a good option (often because of poor health). They are less likely to cure the cancer than surgery, but they can still be very helpful for some people. These treatments are also sometimes used in patients waiting for an organ transplant. Because ablation often destroys some of the normal tissue around the tumor, it might not be a good choice for treating tumors near major blood vessels, the diaphragm, or major bile ducts. Often, ablation can be done without surgery by inserting a needle or probe into the tumor through the skin, guided into place with ultrasound or CT scanning.