The Beam: Dr. Annemarie Shepherd on proton therapy for thymic cancers; NAPT celebrates successes and meet Dr. Winston Vuong

Understanding proton therapy in thymic cancers

Annemarie Shepherd, MD, medical director of Fred Hutch Cancer Center – Proton Therapy, has a special interest in thymic cancers, a type of thoracic cancer. Thoracic cancers develops in the chest, or thoracic cavity, which contains the heart, lungs, esophagus, and other organs.

Shepherd serves on multiple committees in the International Thymic Malignancy Interest Group (ITMIG) and chairs the ITMIG International Tumor Board.

Thymic cancers are extremely rare. They arise from the thymus gland, which is located in the chest above the heart. The thymus gland creates T cells and other immune-related cells that fight infection and is an important immune organ. 

There are two major types of thymic tumors — thymomas and thymic carcinomas.

Thymomas are less aggressive than thymic carcinoma and both are less aggressive than lung cancer, which is the most common type of thoracic cancer. Thymomas are very slow growing and tend to appear in younger populations. The average patient age is around 50, but Fred Hutch physicians often see patients in their mid-20s or 30s.

Because the tumor can sometimes secrete antibodies, thymoma is often closely associated with certain autoimmune conditions, especially myasthenia gravis.

When a person is diagnosed with thymic cancer, the first intervention is usually surgery. If the pathology of the tumor shows that the patient’s chance of a recurrence is high, or if the cancer has invaded other parts of the body, such as the lung or the pleura (the lining around the lungs) then patients often receive radiation.

“Patients with thymomas tend to have a good prognosis and many decades to live,” said Shepherd. That is why she believes proton therapy is an especially important treatment option for thymic cancers.

“Because of the potential for patients to continue to live a long life after treatment, sparing the heart from radiation and thereby reducing the risk of cardiovascular problems such coronary artery disease in the future is so important,” said Shepherd. “The thymus gland lies right above the heart, so in order to know if a patient will benefit from protons, we look at how close the tumor is to the heart before surgery. If all of it lies above the heart, great outcomes can be achieved with standard radiation, but if the tumor has started to wrap around the heart, then proton therapy is preferentially indicated.”

As a particle beam with zero exit dose and minimal delivery of radiation prior to the tumor, proton therapy can more precisely target all its radiation specifically at the tumor. Proton therapy can also be beneficial if there is a larger treatment field, meaning more of the body that must receive radiation, or the tumor is more complicated.

With an existing interest in thoracic cancers, Shepherd is drawn to thymic cancers in part because there is still much controversy and debate over when radiation is indicated in treatment. This controversy fueled her desire to become an expert in finding the best approach for the best outcome.

“At the New York Proton Therapy Center, I began a clinical trial that looked at the benefits versus risks of irradiating the entire pleura with protons to prevent recurrence in patients whose thymic tumor has spread to the pleura,” said Shepherd. “The aim is to decrease the risk of future pleural recurrences, as multiple pleural recurrences are common in thymic tumors. The aim of the trial is to understand if this treatment is worth the potential side effects of scarring or pneumonitis.”

The trial is still ongoing.

Shepherd also became interested in thymic cancers because of the young, motivated patient population and the fact it's a rare cancer, which means it doesn't receive as much funding for research. Shepherd wants to be an advocate.

“I want to get the word out about proton therapy to the thymoma community,” she said. “I hope it will help patients to find the best care, even if there isn’t a proton therapy center near them.” 

The National Association for Proton Therapy celebrates successes in 2024

The National Association for Proton Therapy (NAPT) is an organization dedicated to educating the public and raising awareness of the clinical benefits of proton therapy among patients, providers, payers, policymakers and other stakeholders.

Led by Executive Director Jennifer Maggiore, the association observed several achievements in 2024. 

“Some of our major achievements include the publication of a 10-year study we did on proton therapy trends in the United States, and the first inaugural NAPT Research Forum we hosted in Washington, DC this year, bringing together leading researchers, clinicians and industry experts to discuss advancements in proton therapy,” she said. “But the year saw many advancements in patient access, clinical research and support for patients receiving proton therapy.”  

The 10-year analysis was published in the Red Journal and was based on surveys conducted from 2012 to 2021. The analysis highlights significant trends in treatment complexity and tumor types treated with proton therapy. It showed increasing growth in treatment with protons for head and neck cancers, breast cancer and gastrointestinal tumors, especially, as well as significant increases in central nervous system, childhood cancer and skull-based cancer cases. In general, the use of proton therapy for more complex tumor types increased, while its use for prostate cancer decreased during the same period.

NAPT represents 46 operating proton therapy centers and three future centers. Two centers became operational this year expanding proton therapy access in Illinois and North Carolina. There are several National Comprehensive Cancer Network- and National Cancer Institute-designated hospitals that have proton therapy facilities under construction and several more that are opening in what Maggiore calls the “proton desert” — areas of the country that have few or no proton therapy centers.  

“The opening of proton therapy facilities and increased insurance coverage of proton therapy indicate the importance of protons as a treatment option and the increased interest in it,” Maggiore said. “I am glad to see that recognition as we work hard to build bipartisan support in expanding access to protons. We are seeing more providers and public policy makers support our work.”

At the inaugural Research Forum, which was held at Johns Hopkins' Bloomberg Center, Jeff Buchsbaum, MD, PhD, medical officer in the Radiation Research Program at the National Cancer Institute, and other physician leaders highlighted the future of proton therapy research and the importance of evidence-based cancer care. The forum underscored the need for ongoing collaboration to study and advance proton therapy and to improve patient outcomes. NAPT plans to make this forum an annual event.

This year, the release of preliminary data from a head-and-neck study of proton therapy by MD Anderson Cancer Center in Texas was especially exciting news in the proton therapy community. The multi-institution Phase 3 clinical trial concluded that proton therapy was effective in treating tumors “while producing fewer side effects, emerging as the standard of care treatment that reduces malnutrition and gastrostomy-tube dependence,” according to NAPT’s summary.

NAPT also worked with Fred Hutch Cancer Center – Proton Therapy and NASA to develop a program to reduce anxiety in children and adults receiving proton therapy. It came to fruition in November, when the program officially launched at Fred Hutch, the first center to offer it.

The program, called Mission: All Systems Go!, combines video and handouts to help alleviate the stress of being treated for cancer.

“It was an amazing opportunity to work with one of our member centers and then to be able to bring it to all proton centers,” Maggiore said, adding that she looks forward to working on furthering access to proton therapy for patients around the United States in 2025. 

Meet Dr. Winston Vuong, genitourinary cancer specialist at the proton therapy facility

Winston Vuong, MD, joined the team at Fred Hutch Cancer Center – Proton Therapy in September. 

“I am happy to have proton therapy to offer to the right patients,” said Vuong, who also specializes in kidney and bladder cancers, as well as spinal metastases. He sees patients with these diseases at Fred Hutch’s South Lake Union Clinic.

Originally from Los Angeles, Vuong was the first in his small Vietnamese family to go to college. He got interested in medicine in high school after accompanying his grandfather to his prostate cancer appointments. Later on, while in college, Vuong ended up working with his grandfather’s medical oncologist in research.

“I was very interested in the science of medicine, but also began to see how impactful it can be on patients’ lives,” said Vuong. “I like radiation oncology because it’s a field in which you can spend time with a patient and get to know them. It’s very patient-centric, it can really improve quality of life.”

Vuong also enjoys learning how to push the boundaries of radiation oncology. One of his research interests is finding biomarkers that will indicate what treatments work best or when and why a cancer may be resistant to radiation. He’s also looking into how cancer metastasizes (spreads to another part of the body) and how to interfere with that process to prevent cancer from spreading.

After a residency in Cleveland, Vuong said he is happy to be back on the West Coast, closer to his family. He’s also excited to join an expanding department with an excellent environment of colleague-to-colleague and physician-to-patient support, and “where fresh perspectives are valued.”

He enjoys Seattle and the Pacific Northwest for its diversity (and the resulting delicious cuisine) and access to nature. In his free time, Vuong loves to bake, hike and attend live shows, such as Seattle-based The Postal Service whom he recently saw in concert.

Please say “hi” to Vuong when you see him at the proton therapy facility and share your favorite indie artists or concerts in the area.

Subscribe to our monthly proton therapy newsletter

Get once-a-month updates about proton therapy, including science and medicine news, survivor stories, staff profiles and more.