Stanford’s radiation oncology program is the first in the world to test and use RefleXion, the first biology-guided radiotherapy platform. The groundbreaking technology uses real-time biological signals to guide radiation directly to the tumor, enabling precise cancer treatment. RefleXion’s implementation at Stanford is spearheaded by Stanford Cancer Institute members Lucas Vitzthum, MD, clinical associate professor of radiation oncology, and Murat Surucu, PhD, clinical professor of radiation oncology and chief of clinical physics.
It’s incredible to see something that started at Stanford go from a seed of an idea to actually treating patients."
“It’s incredible to see something that started at Stanford go from a seed of an idea to actually treating patients,” Vitzthum said.
Conventional radiotherapy uses static images and scans taken before treatment to plan radiation administration. MRI-guided radiotherapy uses real-time imaging but is unable to fully track tumor position changes, resulting in less precise targeting.
RefleXion achieves exact, real-time targeting by combining radiotherapy with positron emission tomography (PET), a medical imaging technique that uses radioactive tracers to create detailed images. These tracers have been developed to be absorbed only by cancer cells to precisely image the tumor in real time. They act as a biological beacon, signaling to doctors where to administer radiation, and allow for continuous radiation beam adjustment to account for tumor movement caused by the patient’s normal body activity, like breathing.
“With this device, one of the advantages is that we can use the PET signal emanating from the tumor itself in order to track the tumor, then deliver the dose while we are tracking,” Surucu explained.
This biology-guided radiotherapy technique not only reduces the risk of irradiating and damaging surrounding healthy tissue but also increases the therapeutic effect by delivering a higher dose of radiation directly to the tumor. While traditional radiation plans are delivered exactly as approved, this system holds the potential to vary the dose based on the tumor’s real-time biological signal.
“It’s an inherently different way of delivering radiation than what we’re used to,” Vitzthum said. “We’re still figuring out how to best optimize it for patient care.”
Vitzthum and Surucu have been working with RefleXion since the implementation began at Stanford. The first patient to use this technology was treated in August 2023. Since then, the team has treated over 500 patients with the machine.
“We’ve learned through the initial commissioning with our team, and then we went through treating the first patients. It was very exciting to be helping with the first treatment,” Surucu said.
Stanford’s research led to the technology's initial clearance by the U.S. Food and Drug Administration (FDA) for treating specific lung and bone tumors.
“We’re treating patients with that indication and are also involved in some clinical trials to expand the indications to other sites,” Vitzthum said.
This treatment also aims to address the challenges of treating multiple tumors in different locations in the body.
“Imagine you have a patient with three to four [tumors] in different places in the body. You have to set them up individually, treat them, shift the patient to treat the next one, et cetera,” Surucu described.
Biology-guided radiotherapy streamlines this process by concurrently imaging all tumors in the body, allowing for the simultaneous treatment of multiple tumors, including those whose positions shift due to the patient’s body movement.
With ongoing research and development, the future looks promising for the developing modality of biology-guided radiotherapy.
