RADIATION ONCOLOGY
VETERINARY RADIATION THERAPY
…the fight against cancer
• Nancy Gustafson, DVM, MS, DACVR (Radiation Oncology)
Cancer - what is it and how do you treat it?
What is radiation therapy?
How does radiation therapy work?
What steps are involved in radiation therapy?
What can I expect after treatment?
About our facility
Cancer - what is it and how do you treat it?
Cancerous tumors are made up of aggressive cells which have already escaped the body's first line of defense - the immune system. They invade the local surrounding tissue and may spread (metastasize) to other organs, creating secondary points of attack. Surgery is sometimes all that is needed to cure this disease, but often times more than one medical weapon (i.e., surgery, immunotherapy, radiation therapy, hyperthermia and photodynamic therapy) may be needed to turn the tide against cancer. For example, when the tumor cannot be completely resected (surgically removed), radiation therapy may be able to kill the remaining individual tumor cells.<Back to Top>
What is radiation therapy?
Radiation therapy uses high energy x-rays to kill cancerous cells. The goal is to kill all of the tumor cells while preserving as many normal surrounding cells as possible. Radiation therapy is an effective weapon and can mean a chance to cure your pet's cancer. In human medicine, over half of all cancer patients undergo radiation therapy as part of their treatment. Palliative radiotherapy - used to relieve cancer related discomfort - is also widely used for human patients and is becoming more common in veterinary medicine. Palliative therapy may be recommended for patients with advanced metastatic cancer or other terminal medical conditions. It is particularly effective in alleviating pain in bone cancer. Radiation therapy has the potential to improve the quality of life of your pet whether intended for tumor control or simply to relieve discomfort.<Back to Top>
How does radiation therapy work?
Radiation therapy to kill tumor cells without needlessly harming the normal cells surrounding them requires a very high level of precision. Diagnostic x-rays, ultrasound, CATScan and/or other diagnostic methods are tools that the radiation oncologist uses to determine the treatment area, the appropriate dose and protocol. These decisions are critical in gaining control of the tumor without causing unnecessary damage or complications. Different tissues (and the cells that compose them) have varying tolerances to radiation, but all cells - normal and cancerous - are capable of repairing some of the damage caused by radiation. Radiation induced damage will often cause the cell to die when it attempts to divide. If the damage is repaired before this division, the cell will survive. Cells that grow more slowly are more likely to repair themselves than those that grow more quickly. Tumor cells tend to have a very short life cycle, making their demise following radiation much more likely. The goal of radiation therapy is to eliminate the cancerous cells while sparing the normal surrounding cells. The total dose is divided into small daily doses to allow for maximum repair and cell survival. Known as fractionation, these multiple doses allow the slowly proliferating cells to receive and tolerate a higher total dose of radiation than they otherwise could, thus increasing our ability to achieve good tumor control. This greatly reduces the chance of complications that would otherwise make radiation therapy unsafe.<Back to Top>
What steps are involved in radiation therapy?
Multiple treatments require a great deal of commitment from both the radiation oncologist and you, the owner. Palliative radiotherapy (to alleviate symptoms) requires only a few treatments with a large time interval between each one. Pets receiving radiation therapy for tumor control rather than just palliation require several weeks of treatment, with the therapy being given usually five times per week. Boarding your pet with us during the week is one option that can lessen the frustrations of multiple appointments, work schedules and rush hour traffic. This would still allow you quality time with your pet on the weekends. The use of anesthesia is vital to precisely target the treatment area, and your pet must be well fasted before each anesthesia. Originally, the number of weekly treatments was limited to minimize the stress of anesthesia, however with newer anesthetic agents, daily anesthesia can now be safely administered. Normal tissues have certain tolerance levels to radiation. Exposing them to more than these levels causes tissue damage and serious complications. Gaps in treatment will allow regrowth of the tumor. It is not possible to "catch up" by giving additional doses because the accumulated radiation would be greater than the normal tissue tolerance level. Therefore, it is critical that no treatments be missed unless absolutely unavoidable.If your pet requires multiple types of treatment, they must be well coordinated to achieve the maximum effectiveness of each one. This may include coordinating chemotherapy appointments with surgery and radiation therapy. The radiation oncologist designs a protocol to minimize side effects, but some side effects from radiation are unavoidable. It is important to closely monitor the treatment area when your pet returns home. Depending on the type of treatment, your pet may temporarily lose its hair in the treated area, and may experience a "sunburn" effect. Since irradiated tissues are more fragile, they may require more healing time. Your pet must be discouraged from scratching, licking and biting the area so the effects aren’t worsened. The radiation oncologist will teach you how to care for these effects and review the future plan.
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What can I expect after treatment?
The radiation oncologist will want to see your pet 1 to 2 weeks after treatment to evaluate the treatment area and healing process. Other follow-up examinations will be scheduled at your convenience to monitor the area and assure there is no recurrence, spread of tumor or new tumors (for most patients this will be 3, 6 and 12 months after therapy). Your veterinarian will receive referral letters including all pertinent information so that he/she can be thoroughly familiar with your pet's condition. A duplicate of all follow-up information from our records will be sent to your regular veterinarian's office.<Back to Top>
About our Facility
A special place where your pet becomes part of our family.In addition to state-of-the-art radiation therapy, our facility also provides specialized ancillary care, including cardiology, dermatology, internal medicine, oncology, radiology including a CT scanner, surgery, emergency medicine and 24-hour care. This full-service hospital setting encourages dynamic interaction between specialists for a multi-dimensional approach to your pet's health and medical care.
Our facility is designed with the care and comfort of your pet in mind. A special "family room" creates a home-like environment to lessen stress and provide an area to visit with your pet in a non-medical setting. Owners can also provide audio tapes and/or videotapes which are played daily for their pet as "virtual visitation" in between real life visits and home stays. When you can't be there, our technicians are compassionate in their training, their care and their nature. We emphasize both personal and professional care for each patient and client.
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Nancy Gustafson DVM, MS, DACVR (Radiation Oncology)
Dr. Nancy Gustafson is a board certified specialist in Radiation Oncology. She is a 1999 graduate of Colorado State University's (CSU) College of Veterinary Medicine. She then completed a rotating internship in small animal medicine and surgery at Angell Memorial Animal Hospital in Boston, Massachusetts. Her chosen career in Radiation Oncology led Dr. Gustafson back to academia in 2000 where she pursued advanced training at Colorado State University. In 2003, she completed her residency training program at CSU in Radiation Oncology as well as receiving a Master's degree (Mammalian Radiobiology). In 2004, Dr. Gustafson was an Assistant Professor of Radiation Oncology at Michigan State University College of Veterinary Medicine while simultaneously spending additional time studying medical oncology. Dr. Gustafson believes that deciding to treat a pet's cancer must be based on the latest medical knowledge and advances as well as compassion, reality and the individual patient. She works closely with each owner in making the most effective, caring and ethical decision in the best interest of each patient and owner.<Back to Top>
