What is stereotactic radiosurgery (SRS)? How does it work?
SRS, short for stereotactic radiosurgery, is a new way to deliver advanced radiation therapy that is nonsurgical and noninvasive. It has been proven effective in human health care and is now offered in veterinary medicine through PetCure Oncology’s national network of cancer care partnerships. SRS delivers high doses of radiation to tumors with submillimeter precision, allowing for increased effectiveness and efficiency. The unprecedented precision optimizes impact on the tumor while minimizing collateral damage to nearby healthy tissue, treating the patient with the intent to cure while decreasing the duration and intensity of side effects. SRS treatment can be delivered in just 1-3 sessions – 80-95% less than traditional radiation therapy – which has the added benefits of decreasing risk and expense while increasing convenience and efficiency.
What kind of tumors can SRS treat? Can’t traditional radiation therapy treat the same things?
SRS can be used to treat any tumor or localized cancer. In many instances, this includes tumors that were previously considered inoperable through surgery or untreatable through traditional radiation therapy. Tumors in the brain, nasal or prostate, as well as mast cells or osteosarcomas, for example, are difficult to treat due to their proximity to vital organs and the danger of collateral damage. The submillimeter precision of SRS, however, allows for the tumor to be directly targeted – even if partially embedded in healthy tissue – with minimal damage, if any, to surrounding healthy tissue. You can find out more by visiting our Indications for Veterinary SRS page.
Are the side effects of SRS similar to traditional radiation therapy?
No. One of the primary reasons that pet owners sometimes shy away from traditional radiation therapy is a desire to avoid the complications and side effects commonly associated with low-dose, high-fraction based therapy. SRS significantly reduces the chances and duration of side effects by precisely delivering the radiation dose to the tumor in 1-3 fractions (high-dose, low-fraction) while sparing the surrounding tissue. Most patients experience no worse than some discoloration of the fur on the treatment site or minor inflammation. Typically, a pet will return to normal activities immediately following treatment with a much-improved quality of life.
Is there any research or data on SRS outcomes?
Yes. SRS has been used in human medicine since 1950 for intracranial conditions and since the early 2000’s for extracranial conditions. A significant body of research has been published over that time. Most of the long-term data is derived from human studies, where SRS has shown results significantly better than those achieved with conventionally fractionated protocols, with far fewer side effects. Making the transition from human therapy to pet therapy is based on well-founded principles of radiobiology, and the application of human SRS standards and protocols within veterinary medicine is expected to generate the same or similar outcomes.
With a national network of veterinary SRS centers, PetCure Oncology is uniquely positioned to aggregate outcomes data. Our Scientific Advisory Board includes board-certified human and veterinary oncologists as well as experts in medical physics. Their primary function is to continually study our ever-growing pool of data to establish and refine protocols for the delivery of veterinary SRS. Thus far, the results of SRS for some tumors, such as brain and nasal tumors, is superior to the data from patients treated with conventional protocols. Most patients have benefited from increased survival when compared to other cancer treatment options. It is important to remember that since each radiation treatment in a veterinary patient requires general anesthesia, decreasing the number of treatment sessions from 15-21 down to 1-3 is safer for the patient and leads to a decrease in side effects.
What makes PetCure Oncology’s delivery of radiation therapy different than other locations?
Most PetCure Oncology locations are equipped with a Varian Trilogy that features RapidArc technology and on-board imaging. The on-board imaging leads to improved tumor localization and increased precision, while the RapidArc delivery minimizes the toxicity to healthy tissue and shortens the duration of treatment sessions. In addition, treatments are planned by a board-certified radiation oncologist and delivered by a licensed radiation therapist based on protocols and standards developed by a Scientific Advisory Board. PetCure Oncology’s sites all use specialized software for plan review and verification. These processes reflect the highest standards of radiation therapy delivery in veterinary medicine.
Should I think twice about performing surgery on a pet that could be an SRS candidate?
Yes. SRS cannot be delivered to a pet that has no residual tumor visible on imaging, so a surgical procedure that fails to achieve clean margins may actually eliminate SRS as a treatment option. SRS requires an identifiable target since a large dose of radiation is being delivered with submillimeter precision. If there is no identifiable tumor, the risk to normal tissue is significant.
It is well recognized that complete surgical removal is the best treatment for locally aggressive cancers. However, in the event that the tumor is not completely removable, or where removal would necessitate reconstructive surgery or impact quality of life, then SRS can be a very attractive and effective alternative.
If performing surgery is less than optimal and SRS is being considered as an alternative treatment, keeping the tumor intact is crucial. In fact, SRS has the dual effect of both shrinking and encapsulating the tumor, so the odds of a successful surgery can actually be increased if SRS is delivered first.
How can I explain SRS as a treatment option to my clients in a manner they will understand?
Advanced radiation therapy is complicated, and SRS is a new treatment option that most people are not familiar with. Many are less interested in what it is and more interested in what it can do for their pet. The important thing to convey is that SRS maximizes the dose of radiation to the tumor while minimizing the risk to normal tissues and minimizing the risk of anesthesia. It is delivered with the intent to cure.
SRS is simply one choice among cancer treatment options. It is not always the answer. Our commitment is to support you in presenting your clients with all of the options as you help guide them through the process of selecting what is best for their pet and their family. There are no guarantees in cancer treatment, but in the right situation SRS can be an effective and efficient alternative to traditional radiation therapy, chemotherapy or surgery.
What if SRS is not the right treatment option for my patient?
Our goal is to support you in providing the best possible care to your patients, and that includes making sure we find the most appropriate treatment option for each individual case. While we believe that those options need to include SRS for a client to make a fully informed decision, PetCure Oncology recognizes that every case is different and should be treated accordingly based on the best interests of the pet and their family. If you are not sure whether SRS is appropriate for a particular patient, we encourage you to reach out to the PetCure Oncology location nearest you for a consult.
I am a veterinary specialist with concerns about giving up control of the case. How involved will I be following a referral?
Our intention is not to take control of your patient, but to offer a collaborative approach that is in the best interest of the pet and their family. If you are a veterinary specialist, we hope you view PetCure Oncology as a tertiary referral option that acts as an extension of your practice. If you have a client that can benefit from SRS, we will make sure you have access to the best possible care pathways. During treatment, collaboration and transparency will be paramount. Our team will be in direct contact with you and update you as requested. Upon completion of the treatment, the case will be returned to your practice for ongoing care.
What should I expect following treatment?
In most cases, follow-up visits should be scheduled at two weeks and three months (for a CT) to monitor recovery. These visits are typically conducted by the referring veterinarian, but we are happy to perform the follow-up visits if requested and are always available to help with questions or concerns that may arise after treatment. We don’t want to interfere with your doctor-patient relationship but still want to be responsive to any questions or problems that may arise.
Since the case will typically be returned to you following the referred treatment, clients should be advised to contact you directly with any questions that may come up during the recovery process. Acute post-treatment symptoms are typically minimal and can usually be addressed within your practice. At all times, PetCure Oncology will remain available to you for consultation and collaboration.
How much does radiation therapy at a PetCure Oncology center cost?
Radiation therapy at a PetCure Oncology center can range anywhere from $1,800-$10,000, depending on the course of treatment and the factors of each individual case. SRS falls on the higher end of that scale, while other options such as CFRT or palliative care fall on the lower end. PetCure Oncology recognizes that SRS will not be right for everyone, but we believe that every client should be informed about SRS along with the other appropriate treatment options.
PetCure Oncology has also partnered with CareCredit to provide a third-party financing option at all of our locations. Clients that choose to take advantage of this option will have up to six months to complete payment without interest, or up to five years to complete payment with Care Credit’s standard APR.
Who should I contact if I have questions about a case or want to refer a patient?
You can determine the PetCure Oncology location closest to you and find contact information here. Simply get in touch with the site in your region to initiate the referral process or be connected to the appropriate person for your request.
Why isn’t veterinary SRS more widely available?
There is a national shortage of board-certified veterinary radiation oncologists and veterinary medical physicists, who are required to formulate treatment plans and deliver treatment. Moreover, the capital investment to acquire this technology is significant. As a result, only a handful of U.S. animal specialty hospitals and academic institutions have implemented SRS service to date.
If there is a shortage of veterinary radiation oncologists, how can PetCure Oncology make SRS more accessible?
By partnering with established, respected veterinary radiation oncologists and veterinary specialty hospitals, PetCure Oncology is bringing the technology to sites where clinical expertise in this field already exists. In addition, PetCure Oncology’s Chief Medical Officer, Dr. Neal Mauldin (who is triple board certified in medical and radiation oncology plus internal medicine), is available to perform much of the planning remotely, as well as provide support to the onsite specialty team.
Why is PetCure Oncology creating a national network of SRS centers?
An estimated 12 million cases of cancer are diagnosed in dogs and cats each year, yet when PetCure Oncology was founded, there were fewer than 70 traditional veterinary radiation therapy facilities in the U.S. Of those, less than 10 were providing SRS. This is a significant unmet need that PetCure Oncology is committed to fill.
What makes PetCure Oncology qualified to provide SRS?
PetCure Oncology was created in 2014 by the founders of Accelitech®, the largest privately-held network of human SRS centers developed in partnership with hospitals. Our clinical team is headed by an internationally recognized leader in veterinary medical and radiation oncology, Dr. Neal Mauldin, DVM, DACVIM, (Internal Medicine and Oncology), DACVR (RO). PetCure Oncology’s medical standards are also driven by a Scientific Advisory Board that consists of leading experts in the field.