Inova proton therapy shows survival benefit in landmark phase III trial for head and neck cancer patients

FAIRFAX, VA – A new study published today in The Lancet demonstrates a significant survival benefit for patients with oropharyngeal cancers of the head and neck treated with proton therapy compared with traditional radiation therapy (photon therapy). Inova Schar Cancer and The Mather Proton Therapy Center, home to Northern Virginia’s only proton therapy center and one of only 40 in the country, was among a select group of community-based cancer centers participating as co-investigators on this landmark multi-institutional, prospective Phase III trial.

Given their proximity to critical organs, oropharyngeal cancers are well suited for proton therapy, which can reduce radiation to healthy tissue, making this cancer type an ideal focus for a large Phase III study comparing treatment approaches.

The study included 440 patients, with advanced disease and enrolled patients across 21 sites in the U.S., making it the most comprehensive Phase III trial comparing proton therapy to photon therapy for oropharyngeal cancers.

“This study represents a major milestone in the treatment of head and neck cancers,” said Gopal Bajaj, MD, MBA, FASTRO, Emeritus Chairman and Medical Director of Inova Schar Cancer Radiation Oncology and Proton Therapy. “The results show that proton therapy not only dramatically improves survival but also enhances post-treatment quality of life for patients by reducing feeding tube dependence, long-term swallowing issues, and dry mouth. Importantly, it demonstrates Inova’s commitment to providing world-class care and advanced technology right here in Northern Virginia.”

Key findings:

• Survival: At five years, survival was 90.9% for patients treated with proton therapy, compared with 81% for those who received traditional photon therapy.
• Quality-of-Life Advantages: Patients treated with proton therapy experienced less swallowing difficulty (34% vs. 49%), lower feeding tube dependence (26.8% vs. 40.2%), less dry mouth (33% vs. 45%), and higher immune cell counts compared to traditional radiation therapy.

The Mather Proton Therapy Center at Inova Schar Cancer

Proton therapy, or intensity-modulated proton therapy (IMPT), targets cancer cells with high precision, sparing surrounding healthy tissue from excess radiation. Inova is the only proton therapy center in Northern Virginia and one of roughly 40 centers nationwide, giving local patients access to leading-edge cancer-fighting technology without leaving the region.

Inova’s head and neck cancer multidisciplinary team includes world-class otolaryngologists, plastic surgeons, medical and radiation oncologists, radiologists, pathologists, speech and physical therapists, nutritionists, social workers, Life with Cancer specialists, and nurse navigators; ensuring comprehensive, patient-centered care that translates the latest research findings directly into patient outcomes.

About Inova

We are Inova, Northern Virginia and the Washington, DC, metropolitan area’s leading nonprofit healthcare provider. With expertise and compassion, we partner with our patients to help them stay healthy. We treat illness, heal injury and look at a patient’s whole health to help them flourish. Through our expansive network of hospitals, primary and specialty care practices, emergency and urgent care centers, and outpatient services, Inova provides care for more than 1 million unique patients every year. Total patient visits exceed 4 million annually, demonstrating our ability to deliver the best clinical care and ensuring a seamless experience for all who rely on us for their healthcare needs.

Consistently ranked and recognized as a national healthcare leader in safety, quality and patient experience, Inova’s world-class care is made possible by the strength and breadth of our network, our 26,000 team members, our technology, and our innovation. In 2025, Inova was named the Health System of the Year by Press Ganey, a national leader in healthcare experience, recognizing our excellence in patient care, team member engagement and commitment to continuous improvement. 

Inova is home to Northern Virginia’s only Level 1 Trauma Center and Level 4 Neonatal Intensive Care Unit and provides high-quality healthcare to each person in every community we are privileged to serve – regardless of ability to pay – every day of their life. More information about Inova can be found at Inova.org.