Protecting normal tissue is very important, so the type of heating device depends on the location of the tumor. Hyperthermia is often combined with other cancer treatments such as radiation therapy or chemotherapy. In combination, they work synergistically to kill additional tumor cells. Hyperthermia is currently available for the treatment of pets with cancer at a limited number of veterinary teaching hospitals. Studies are ongoing to determine how to uniformly heat a variety of tumor types, and to determine the optimal dose of hyperthermia.
Cryosurgery is a method of killing tumor cells with extreme cold temperatures using liquid nitrogen.
The tumors best treated with cryosurgery are small, benign masses less than one inch in diameter. Typically, these masses are located on the eyelid, anus, mouth, or skin. Depending on the location of the tumor, the patient may require sedation, local anesthesia, or general anesthesia to perform cryosurgery. After a special drug has been administered to the patient, a laser light source causes tumor death by activating the drug locally. A laser light source is used to activate a photosensitizer absorbed in the tissue from the special drug.