Cryotherapy treatment (also called cryoablation) is a promising new minimally invasive technique in which surgeons use very low temperatures to kill kidney cancer cells. Cryotherapy treatment is appropriate for small kidney tumors (less than 4 cm). During cryotherapy treatment surgeons insert several needles into the kidney tumor. Argon and helium gas circulate through the needles, lowering the temperature to -40°C for several minutes. Surgeons can control the extent of freezing and evaluate the kidney and needle placement with ultrasound imaging during the procedure. Depending upon the location of the tumor, doctors perform cryotherapy either through a laparoscopic or CT guided approach (which is done without incisions).