VOLO™ ULTRA Experience: Nasal Carcinoma in a Dog

CASE STUDY | VOLO™ ULTRA OPTIMIZER • UW VETERINARY CARE

VOLO™ ULTRA Experience: Nasal Carcinoma in a Dog

This case demonstrates the benefits of accurate and fast Accuray Precision® Treatment Planning System with VOLO™ Ultra in a dog with a squamous cell carcinoma in the nasal region

What is VOLO Ultra

VOLO Ultra is a planning and optimization option for the Accuray Radixact® Treatment Delivery System. This state-of-the-art optimizer simplifies the process of creating treatment plans by leveraging industry-established techniques and user experience. It’s intuitive planning approach based on weighted cost function optimization eliminates the need for setting of VOI importance and overlap priorities. An automated pitch selection and accelerated treatment time option enables clinicians to efficiently create plans and provide optimal treatment for patients.

Clinical History

A dog was presented for evaluation of melanoma on the right lip. A CT was performed, and a nasal mass was incidentally found. Biopsy was consistent with non-keratinizing squamous cell carcinoma. Owner elected curative-intent, hypofractionated radiation therapy (42 Gy in 10 fractions).

Case Challenge

The staff at UW Veterinary Care routinely struggled to ensure adequate dose coverage to the PTV while minimizing dose to the left and right eyes / lens, specifically in the posterior nasal cavity between the eyes. VOLO Ultra has enabled minimization of dose to OARs while still ensuring dose coverage of the PTV in this area. It also enables a plan to be completed in a fraction of the time compared to VOLO Classic.

This case was optimized using VOLO Ultra and VOLO Classic. Optimization took a total of approximately 5-10 minutes for the VOLO Ultra plan and a total of 1 hour 20 minutes for the VOLO Classic plan. Fairly similar dose coverage and minimization of dose to OARs was achieved for each plan, although minimization of dose to OARs for the VOLO Ultra plan was slightly improved compared to the VOLO Classic plan.

Facts at-a-glance

WHO/WHERE

Nate Van Asselt, DVM, DACVR (Radiation Oncology) Clinical Assistant Professor, Radiation Oncology
University of Wisconsin School of Veterinary Medicine – Madison, Wisconsin

ABOUT

UW Veterinary Care’s small animal oncology specialists offer a team-focused approach to cancer care in veterinary patients. This comprehensive approach to the management and treatment of a pet’s cancer enables both medical oncology and radiation oncology clinicians to work closely with each other, as well as with surgeons, pathologists and radiologists, to quickly and efficiently determine the best options for each patient. The result often involves a combination of chemotherapy, radiation therapy, immunotherapy and/or surgery.

TECHNOLOGY SOLUTION

Radixact® Treatment Delivery System and Accuray Precision® Treatment Planning System with VOLO™ Ultra.

Planned and Optimized with VOLO™ Ultra

Planned with VOLO™ Classic

“We are able to achieve robust and efficient plans using VOLO™ Ultra in a fraction of the time it would take to obtain plans with the VOLO Classic planning software. The plans that we make with VOLO Ultra are always as good and often better, than VOLO Classic.”

Nate Van Asselt, DVM, DACVR

Clinical Assistant Professor, Radiation Oncology
University of Wisconsin School of Veterinary Medicine

Treatment Details

The oncology team at UW Veterinary Care obtained the VOLO Ultra plan in approximately 10 minutes whereas it took about 90 minutes to obtain the VOLO Classic plan. In the end the beam on times were similar, about 480 seconds each. Since the patient is under general anesthesia, beam on time is not as high of a priority as with human radiotherapy facilities. The target coverage was similar between the plans (99% of the prescribed dose of 42 Gy to 95% of the PTV). Dose was minimized to the eye on the side ipsilateral to the target to a greater degree on VOLO Ultra compared to VOLO Classic. Dose (50%) to the left eye in VOLO Ultra plan was 6.99 Gy while it was 9 Gy in the VOLO Classic plan.

Treatment Rationale

The most aggressive nasal radiation protocol the UW Veterinary Care Oncology Team uses is a ten-fraction protocol (42 Gy in 10 fractions). The goal in these cases is to provide a robust tumor response over the course of a year, resulting in improved quality of life for the dog.

Outcome

Typically, 1-2 months post treatment shows a partial to complete response from a full course of radiation therapy. Dogs can experience survival times typically around 12-18 months. Progression is likely in many cases and expected, because of a robust gross tumor presence within the nose. It is uncommon in dogs to find nasal tumors that are not occupying the majority of at least one side of the nasal cavity.

Important Safety Information:
Most side effects of radiotherapy, including radiotherapy delivered with Accuray systems, are mild and temporary, often involving fatigue, nausea, and skin irritation. Side effects can be severe, however, leading to pain, alterations in normal body functions
(for example, urinary or salivary function), deterioration of quality of life, permanent injury, and even death. Side effects can occur during or shortly after radiation treatment or in the months and years following radiation. The nature and severity of side effects depend on many factors, including the size and location of the treated tumor, the treatment technique (for example, the radiation dose), and the patient’s general medical condition, to name a few. For more details about the side effects of your radiation therapy, and to see if treatment with an Accuray product is right for you, ask your doctor. Accuray Incorporated as a medical device manufacturer cannot and does not recommend specific treatment approaches. Individual results may vary.

VOLO™ Ultra is not available for sale in all markets. VOLO Ultra may be subject to international regulatory approval or licensing processes such that the availability of these products may
vary according to geographical location.

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