Radiation therarphy

Radiation therapy — also called radiotherapy — is a highly targeted, highly effective way to destroy cancer cells in the breast that may stick around after surgery.Radiation therapy uses radiation (high-energy rays) to kill or shrink tumour cells. It is used to treat some, but not all cancers. Radiation therapy destroys cells either directly or by interfering with cell reproduction. Normal cells are able to recover from radiation damage better than cancer cells.Used alone, radiation therapy can cure cancer in many cases. It is also used in combination with other treatments or therapies such as surgery or chemotherapy. It might be used to both reduce the size of tumours before surgery or to destroy any remaining cancer cells after surgery.

Radiation therapy is commonly applied to the cancerous tumour. The radiation fields may also include the draining lymph nodes if they are clinically or radiologically involved with tumour, or if there is thought to be a risk of subclinical malignant spread. It is necessary to include a margin of normal tissue around the tumour to allow for uncertainties in daily set-up and internal tumor motion.

Radiation, at levels thousands of times the amount used to produce a chest x-ray, destroys the ability of cells to divide and grow. Both normal and cancer cells are affected, but the radiation treatment is designed to maximize tumor effect and minimize normal tissue effect. Maximizing tumor effect is one reason radiation therapy is given in a series of treatments rather than one treatment.

Radiation therapy can offer, in some instances, permanent control of tumors that cannot be controlled by surgery or chemotherapy,. In other cases, even when cure is not possible, radiation therapy can still bring a measure of relief. Shrinking a large tumor with radiation therapy may improve the quality of life by reducing pressure, bleeding or pain.During treatment, the cancer specialist will monitor the effect of the radiation on the cancer as well as on normal tissue. It may be necessary to alter the plan because of changes in the tumor or normal tissue, but this is usually not necessary. Most side effects that occur during radiation therapy, although unpleasant, are usually not serious.When cancer of the oral or nasal cavity is treated with radiation therapy, a foul odor may develop as the tumor is destroyed by the radiation. This odor is usually temporary and decreases as the tumor dies.

It is important for your veterinarian to examine your pet periodically after radiation therapy is over. This will allow normal tissue side effects to be detected before they become advanced, and the effect of the radiation on the tumor to be evaluated. It is the goal of radiation to completely eradicate the cancer. In some pets this happens and no evidence of the tumor persists. In other pets the cancer or lump may never completely disappear, but growth is arrested and the tumor is essentially controlled. The specific results to be expected depend on many factors. Specific details on likelihood of success for a specific tumor will be provided to you by the cancer specialist.
Finally, it is important to realize that even though your pet may never be totally the same as before the cancer was diagnosed, it is possible in many pets to provide additional comfortable months or years of happy life through radiation therapy.