Radiation therapy 
It is a form of treatment that uses ionizing radiation (x-rays, gamma-rays and electrons) to treat localized tumors and, occasionally, widespread diseases such as lymphoma as well as selected benign diseases. Radiation therapy is designed to destroy target cells, such as cancer cells while minimizing radiation to healthy tissues so that they can recover from any radiation effects.
We have a Linear Accelerator (Linac), the state of the art equipment for the treatment of most tumors. We also have a Strontium-90 surface applicator for treatment of very superficial skin and ocular tumors.

Objective of radiation therapy
The basic principle of radiation therapy is that treatment should always benefit the patient, even though the treatment outcome may not be entirely predictable.  The goal of radiation therapy is to deliver a precisely measured dose of radiation to a defined tumor volume with minimal damage to surrounding healthy tissue.  A successful treatment is achieved when the tumor is completely eradicated and the surrounding normal tissues are spared, resulting in eradication of tumor as well as a high quality of life with no long term complications.

Treatment goals
The selection of patients for radiation therapy should involve consultation with a radiation oncologist, preferably in a multidisciplinary clinic setting with involvement of a medical and surgical oncologist, and should include consideration of all aspects of the individual patient’s condition. After evaluation of the extent (staging) and pathologic characteristics of the tumor and overall patient’s health, the goal of radiation therapy is determined. The primary goal of radiation therapy is to eliminate the cancer with minimal side-effects.  Although radiation therapy is most commonly used with curative intent, it is also used to slow down tumor growth and improve quality of life when cure is not achievable. This is called palliation, and is commonly done to slow tumor growth and control pain.  Palliation should not be viewed as an unworthy goal, as many animals may live for long periods in comfort when they have residual tumor or metastasis.
A correct assessment of the treatment goal is one of the most important decisions in radiation therapy. Overly aggressive treatment plans can expose animals that are not curable to needless morbidity, prolonged and expensive treatment, and unnecessary radiation effects. On the other hand, therapeutic decisions that are too pessimistic deprive the animal of a real chance for cure.

Clinical role
Access to modern equipment and the evolution of veterinary oncology into a multidisciplinary specialty have led to an increasing role for radiation therapy in the management of cancer in small animals.   Radiation therapy can be used alone or in combination with surgery or chemotherapy.  Its increased application has led to a significant decrease in the need for radical surgery in many common cancer.