Radiation treatment has proven to be a vital tool for improving the health of a number of cancer patients. This critical aspect of care at the CVS Angel Care Cancer Center is quite unique because it is performed in our own state of the art facilities in Carlsbad, California, and in cooperation with regional human radiation oncologists and radiation therapy centers.
We are the ONLY center in the world that provides “high tech and high touch” linear accelerator generated radiation therapy with both photon and electron beam radiation, Trilogy based stereotactic radiosurgery (SRS) and the robotically controlled, computer controlled, Cyberknife stereotactic radiosurgery. Similarly, CVS stands ready to diagnose each problem with access to state-of-the-art diagnostics, including computerized tomography, PET/CT, MRI, ultrasound, color flow Doppler, and digital radiology.
How is Radiation Therapy Administered
Whenever radiation therapy is planned for a pet with cancer, maintaining the quality of life and freedom from discomfort are our highest goals. Because not every treatment modality is right for every patient, each plan is individualized. Our Radiation Oncology team works with your family and your referring veterinarian to ensure your pet is as comfortable as possible while undergoing radiation treatments and any side effects are managed. We make it a priority to address any questions or concerns as they arise. To minimize the adverse effects and to enhance the control of cancer, small dosages are administered over several weeks.
During each treatment, your pet will be placed under a light level of anesthesia, and a machine will be used to safely and precisely direct the healing radiation therapy beams over a period of a few minutes. The radiation oncologist will determine the appropriate dosage and number of treatments to ensure the best outcome possible. When radiation is used with the intent of eliminating or controlling cancer for a long period (definitive treatment), 16 to 19 treatments are administered over four weeks. Other, more palliative approaches may have one to six dosages. These treatments take only a few minutes to administer, and they are not painful.
Definitive Radiation Therapy
Definitive Radiation Therapy:
Definitive radiation therapy is used to treat tumors with the intent of providing long-term disease control for the patient. Given the larger doses administered, this treatment requires breaking up the treatment into multiple smaller doses to reduce the risk of causing long-term side effects. Typically, this treatment will entail the delivery of anywhere between 16 to 19 treatments which are administered daily on a Monday through Friday basis.
Stereotactic Radiotherapy (SRS/SRT)
Stereotactic Radiotherapy (SRS/SRT): SRS/SRT is a more advanced type of definitive therapy for patients with certain types of tumors. As with definitive radiation therapy, the objective of SRS/SRT is long-term disease control. The higher degree of precision attained with SRS/SRT allows for the delivery of higher doses of radiation without causing increased side effects. Most SRS/SRT treatments are administered over a period of consecutive days.
Palliative Radiation Therapy
Palliative Radiation Therapy: Palliative radiation therapy has a primary goal of reducing the discomfort caused by many tumors. Tumors frequently cause discomfort for patients due to encroachment on surrounding tissues, inflammation and destruction of bone. This discomfort will frequently result in a diminished quality of life for cancer patients. The goal of palliative radiation is to improve a patient’s quality of life by reducing tumor-associated pain, inflammation and, in some cases, reduce the size of the tumor. Additionally, the intent is to deliver this treatment without causing side effects. This goal is achieved by delivering lower doses of radiation than those delivered with a definitive course of radiation therapy. A typical palliative radiation treatment course would consist of 2 to 6 treatments over a relatively short period.
External Beam Radiation Therapy
External beam radiation therapy is delivered by a linear accelerator. It does not make your pet radioactive and is similar to the process of getting a chest or dental x-ray or radiograph.
CyberKnife® Robotic Radiosurgery System
The CyberKnife® Robotic Radiosurgery System is the world’s first and only robotic radiosurgery system designed to treat both cancerous and non-cancerous tumors throughout the body non-invasively. It provides a pain-free, non-surgical option for patients who have inoperable or surgically complex tumors, or who may be looking for an alternative to surgery. The treatment, which delivers beams of high dose radiation to tumors with extreme accuracy, involves a team approach in which several specialists participate.
Before the procedure, the patient is imaged using a high-resolution CT scan, to determine the size, shape, and location of the tumor. Following scanning, the image data is digitally transferred to the CyberKnife System’s workstation, where the treatment planning begins. A qualified clinician then uses the CyberKnife software to generate a treatment plan. The plan is used to match the desired radiation dose to the identified tumor location while limiting radiation exposure to the surrounding healthy tissue.
Once the treatment plan has been developed, the patient is ready to undergo the CyberKnife procedure. After arriving at the CyberKnife Center, patients are comfortably positioned on the treatment table. Then the CyberKnife System’s computer-controlled robot will slowly move around the patient to the various locations from which it will deliver radiation to the tumor.
Each treatment session will last between 20 and 40 minutes, depending on the type of tumor being treated. If treatment is being delivered in stages, patients will need to return for additional treatments over several days (typically no more than five), as determined by the patient’s doctor. Occasionally patients experience minimal side effects, but those often go away within the first week or two after treatment.
Dr. David Proulx discusses Cyberknife on KUSI- Video
Possible Side Effects
The goals of palliative radiation treatment include improving the quality of life for many patients without causing significant side effects.
In the course of definitive or curative radiation treatment, some surrounding normal tissue will be affected. Radiation-induced effects on normal tissues usually do not begin until the end of the therapy period, and they continue for 2-3 weeks after the treatment has ended. These are called the acute side effects, and they usually resolve within weeks after radiation has been completed. Other adverse effects associated with radiation therapy may occur months or years after radiation is complete. These are called delayed adverse effects. Interestingly, the adverse effects associated with radiation therapy are much less in pets than in most other species, including people. Indeed, the majority of these adverse effects are mild and self-limiting. We will work with you to ensure that your pet is as comfortable as possible during this 2- to 4-week period when adverse effects are noted.
Not all types of radiation are suitable for each patient. A combination of your pet’s individual circumstances (age, tumor type, tumor location, stage of disease) and your family’s goals will help to determine which treatment is best for your pet. Our radiation oncologist is available to discuss these factors further with you.
What is a Veterinary Specialist?
A primary care veterinarian treats a broad variety of animals and conditions. Veterinary specialists, however, must complete an internship, a two to four-year specialized residency, publish a paper in a peer-reviewed journal, in addition to receiving their veterinary degree. Specialists must also undergo a series of rigorous examinations based on knowledge and skill in the given specialty.
Radiation Oncology Doctors
Our vision is to lead the specialty veterinary profession by providing Special Care from the Heart combined with the latest in medicine, science, and technology to better diagnose and treat our patients.