Radiation therapy might also be an alternative to radical surgery in certain locations, such as the head and limbs. A combination of surgery and radiation may provide tumor control while maintaining good function and appearance. Chemotherapy Chemotherapy is the treatment of choice for patients with systemic cancers such as leukemia and lymphosarcoma. Chemotherapy is also used in combination with surgery and radiation therapy in the treatment of localized high-grade tumors that are likely to metastasize. The goal of chemotherapy is to prolong a good quality of life by delaying the onset of metastasis and associated symptoms.
Veterinary medicine uses the same chemotherapy drugs used in human oncology.
However, veterinarians typically use lower dosages, fewer combinations, and less frequent administration than human oncologists such that the occurrence of serious side effects and the need for hospitalization is kept to a minimum. The cause of treatment failure is usually due to the development of chemotherapy-resistant tumor cells. More effective treatments are needed for many veterinary cancer patients. Clinical trials are being conducted in both veterinary and human oncology in order to find new and improved treatments for those patients not cured by conventional therapies. In addition, dogs and cats live in the same environment as their human companions, and they develop many of the same types of cancers as do humans.