CyberKnife makes its veterinary medicine debut

CyberKnife at the BluePearl Veterinary CyberKnife Cancer Center

Blue Pearl veterinary hospital in Malvern, Pennsylvania, has become the only veterinary clinic in the world to use the CyberKnife, a state-of-the-art equipment that provides treatment and care to patients with cancer. According to an organizational release,¹ CyberKnife is a noninvasive treatment for tumors that are cancerous or noncancerous as well as other conditions that utilize radiation therapy.

The CyberKnife is currently the only radiation delivery system that features a linear accelerator directly mounted on a robot to deliver patients high-energy x-rays or photons used for radiation therapy. The technology works by the robot moving and bending around the patient to deliver a radiation dose from possibly thousands of different beam angles.² Through this process, it provides real-time imaging guidance to expand the positions available to concentrate radiation to the tumor and minimize the dose to healthy tissue surrounding it.

“What we're able to do is visualize a tumor and then deliver anywhere from 1 to 5 treatments of CyberKnife radiation therapy, where we're able to concentrate the dose of radiation within the tumor, and very little radiation is received by the outside, healthy surrounding structures,” Siobhan Haney, VMD, MS, DACVR (RO), MBA, radiation oncologist, BluePearl Malvern, explained in an exclusive interview with dvm360®.¹

“So this really works out favorably in so many ways because it means less toxicity for our patients, [and] fewer radiation side effect. In fact, in some cases, there are even no radiation side effects, fewer times under anesthesia, and we're really able to accomplish historically what we would do over a 4-week period with anywhere from 16 to 20 treatments of radiation. Now, we can consolidate that down and do it in less than 1 week,” she continued.

The CyberKnife Cancer Center, located next to the BluePearl Malvern main hospital, is a dedicated facilities that provides treatment for patients with cancer. Through the CyberKnife, patients receive pain-free and nonsurgical option the team can give to patients with cancerous, noncancerous, inoperable, and surgically complex tumors with no recovery time needed.

“If your pet is diagnosed with cancer, it can be an incredibly traumatic time, full of uncertainty and fear” Richard Stone, DVM, chief medical officer at BluePearl, said in the release.¹ “Our team in Malvern is providing the highest quality of care to pets that are diagnosed with cancer, with our Veterinary CyberKnife Cancer Center using industry leading treatments that are designed to improve the lives of pets that are diagnosed. The fact that we are home to the world’s only CyberKnife that is solely used in veterinary medicine speaks to the highest level of care that we can provide to pets when they need us most.”

In 2021, because there is somewhat limited data about the efficacy and prognostic factors that influence the outcomes of canine patients with intracranial neoplasia treated with CyberKnife, investigators set out to determine the prognosis and associated factors for canine patients that were imaged, determined to have primary intracranial tumors, and then treated with CyberKnife radiotherapy.

The investigators reviewed medical records of cases from January 2010 to June 2016 and extracted medical data including signalment, weight, seizure history, tumor location and type, gross tumor volume, planned tumor volume, treatment date, radiation dose, recurrence, date of death, and cause of death of 59 dogs, according to the study.3 The study found that the progression‐free interval (PFI) for canines with intracranial tumors treated with CyberKnife was 347 days, and the median survival time (MST) was 738 days. Tumor location was significantly associated with PFI when comparing cerebrum (median PFI 357 days; range 47‐1529 days) versus cerebellum (median PFI 97 days; range 97‐168 days) versus brainstem (median PFI 266 days; range 30‐1484 days), P = .03. Additionally, the presumed tumor type was significantly associated with MST (P < .001).³

The researchers also noted that only 1 adverse effect was reported but the protocols of CyberKnife have demonstrated to have improved adverse effects when compared to fractionated radiation protocols, with their findings lower than anticipated. Researchers believe that this finding may because of lack of follow up data rather than a truly lower risk of adverse effects. The investigators also disclosed that the study had limitations because of the retrospective nature of the study but concluded that the use of CyberKnife and Stereotactic radiotherapy might improve MST compared to radiation therapy.³

Although this is a new product in the veterinary space, research has been done on its efficacy on the human side of medicine. In a study evaluating the safety and efficacy of the CyberKnife for meningiomas, on February 21, 2024, researchers conducted a comprehensive investigation across PubMed, EMBASE, Web of Sciences, Google Scholar, and Cumulative Index to Nursing and Allied Health Literature to gain access to relevant literature discussing the use of CyberKnife radiosurgery for meningioma treatment within the last 20 years. The investigators noted that their search strategy was to include terms related to meningioma and CyberKnife without combining them with other treatments, focusing on tumor control rate, survival rate, symptom relief, quality of life, and adverse events.⁴

From the 21 studies the researchers utilized, they found that this treatment modality is a significant advancement, especially for those contraindicated from surgery or have tumors in an anatomically challenging position. Investigators also found that the CyberKnife is playing an integral role in the management of meningiomas, is safe, successful, and has a positive impact on the patients outcome.⁴

“If somebody had told me 15 years ago that I would be treating [patients with] a CyberKnife today, I probably would have laughed at them and said, ‘no way we're going to be able to get that in veterinary medicine.’ But here we are today, and we're super proud of being the only site [using it] and just able to really offer very comprehensive care,” Haney conclued.

“It's not just the CyberKnife that we have available here. We've got a traditional, standard linear accelerator. We also have a very comprehensive oncology group, because radiation can't be taken just simply by itself. We've got to work as a team,” Haney added.

Haney informed dvm360 that Blue Pearl Malvern staff can continue their work thanks to partnerships with referral veterinarians, because they rely on them heavily for care after CyberKnife treatment. Any interested veterinarians can learn more about the CyberKnife and referral information on the BluePearl Veterinary CyberKnife Cancer Center website.

References

1. The World’s Only Veterinary CyberKnife is Used at BluePearl Malvern. News release. BluePearl Pet Hospital. September 4, 2024. Accessed September 4, 2024.
2. How it Works. CyberKnife. Published 2020. Accessed September 4, 2024. https://cyberknife.com/cyberknife-how-it-works/
3. Carter GL, Ogilvie GK, Mohammadian LA, Bergman PJ, Lee RP, Proulx DR. CyberKnife stereotactic radiotherapy for treatment of primary intracranial tumors in dogs. J Vet Intern Med. 2021;35(3):1480-1486. doi:10.1111/jvim.16086
4. Bin Sumaida A, Shanbhag NM, Balaraj K. Evaluating the Efficacy and Safety of CyberKnife for Meningiomas: A Systematic Review. Cureus. 2024;16(3):e56848. Published 2024 Mar 24. doi:10.7759/cureus.56848