With GammaPod, radiation oncologists will be at the forefront of a new era in cancer care by providing stereotactic radiotherapy treatments for the breast. 

 The delivery of higher doses in one or several large fractions differentiates stereotactic radiotherapy, also known as stereotactic body radiation therapy (SBRT), from conventional techniques. 

Xcision Founder and CEO Cedric Yu, DSc., clinical professor of radiation oncology at the University of Maryland School of Medicine, said, "Every aspect of the GammaPod system has been optimized to noninvasively treat targets within the breast using highly conformal dose distributions. 

 The sharp falloff outside the target volume results in exceptionally low doses to surrounding healthy breast tissue and organs like the heart and lungs.

"We set out to design a solution in a real-world clinical setting that would be more convenient for patients, more efficient for hospitals and clinicians and more cost effective for our health care system.  GammaPod aligns well with the future of health care in the United States and around the world."

Breast cancer is the most frequently diagnosed tumor site in the majority of countries worldwide, accounting for about 12% of new cases annually and 25% of cancers in women.  In the US each year, 61% of women with breast cancer are diagnosed with localized disease, along with an additional 63,000 cases of ductal carcinoma in situ (DCIS). 

 Most of these women are eligible for breast conserving surgery, which includes lumpectomy followed by radiotherapy.  Approximately one-third of patients instead receive a mastectomy, which is associated with higher costs and complications. 

"GammaPod is a new option for use in conjunction with breast conserving treatment," Yu said. "We hope clinicians and patients see the appeal of this short-course, noninvasive treatment."

Stereotactic treatments require a high degree of precision.  To maintain high levels of geometric accuracy, patients are fitted with a breast cup immobilization device. The outer breast cup contains a fiducial wire, which localizes the target and provides the stereotactic coordinates for planning and treatment. 

After imaging, treatment planning is performed while the patient is set up on the GammaPod for treatment.  A robotic system rotates the patient from standing to prone position, which has been shown to offer superior sparing of the heart and other critical structures compared to other radiation therapy techniques for many breast cancer patients. 

During treatment, radiation sources rotate around the affected breast in synchrony with 15mm and 25mm collimators, effectively creating thousands of beam angles.  Additionally, the table moves during treatment to allow dynamic dose painting as the target moves through the focal spot of radiation where the beams converge.

Yu invented GammaPod in collaboration with William F. Regine, MD, FACR, FACRO, the Isadore & Fannie Schneider Foxman Endowed Chair and professor of radiation oncology at the University of Maryland School of Medicine.

"GammaPod will be a significant tool in our technology armamentarium for treating breast cancer patients more efficiently and precisely," said Regine.  "In an academic institution like the University of Maryland, our mission is to research practice-changing approaches to improve care.  GammaPod certainly has the potential to do just that."

GammaPod will be used in multiple clinical trials at GammaPod research consortium sites— which include University of Maryland as the academic lead, UT Southwestern Medical Center in Dallas, The Ottawa Hospital in Ontario and Alleghany General Hospital in Pittsburgh. 

Investigators hope to demonstrate that ultra-accelerated stereotactic partial breast irradiation can deliver equivalent or superior local control with less toxicity and improved cosmetic outcomes compared to linear accelerator-based APBI techniques as well as invasive brachytherapy techniques.

Trials will also study pre-operative SBRT.  A recent study at the University of Maryland School of Medicine found that 15% of patients receiving pre-operative radiation had a complete pathological response to the treatment.

Principal investigator Elizabeth Nichols, MD, assistant professor of radiation oncology at the University of Maryland School of Medicine and clinical director of the Department of Radiation Oncology at the University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center said, "Our hope with GammaPod is to one day identify a subset of patients for which surgery is not required."