The field of head and neck oncology is currently witnessing a paradigm shift, as the “more is better” approach to radiation is giving way to a sophisticated “precision-first” philosophy. In a recent discussion with CancerNetwork®, Jason Molitoris, MD, PhD, associate professor of Radiation Oncology and director of the Clinical Hyperthermia Program at the University of Maryland, detailed why intensity-modulated proton therapy (IMPT) has officially transitioned from an experimental alternative to a definitive standard of care for oropharyngeal squamous cell carcinoma (OPSCC). This was contextualized by a presentation he gave at the American College of Radiation Oncology (ACRO) 2026 Radiation Oncology Summit.1
Driven by landmark phase 3 data released in 2025, Molitoris highlighted a critical evolution: looking beyond survival to consider the quality of survival. For the rising demographic of younger patients with p16-positive disease, the goal is to minimize long-term adverse effects that can persist for decades. The rationale for IMPT over traditional photon therapy lies in its unique physical properties, with Molitoris emphasizing 2 takeaways: immune preservation and functional longevity.
Molitoris also addressed geographic and socioeconomic disparities in the field. Through innovative “cost-neutral” billing systems and logistical support at the University of Maryland, his team is working to ensure that a patient’s zip code doesn’t determine their access to life-altering technology.
Looking ahead, the next 3 to 5 years may promise even greater refinement. Through volume de-escalation and risk-stratification—potentially guided by circulating tumor DNA (ctDNA)—the oncology community is moving toward a future where treatment is as unique as the patient’s own biology.
What was the rationale for your presentation on proton therapy for oropharyngeal cancer?
The rationale for the presentation was that there were some big new data that were presented in 2025, and the organizers of the meeting wanted to have a discussion about the use of proton therapy in OPSCC given these new data that we have available to us now.
What are some of the main takeaways from your presentation?
What I tried to do was highlight different areas in which we use proton therapy for oropharyngeal cancer and highlight some of these newer data that have emerged. We talked a bit about use of proton therapy in treatment of patients where you treat bilateral cervical nodal disease, and then also patients whom we treat either postoperatively or patients where we only have to treat one side of the neck.
Can you elaborate on the theory that reduced doses to the bone marrow and circulating lymphocytes preserve the immune system’s ability to monitor cancer?
This is something that is exciting and very exploratory based on the Lancet article on the University of MD Anderson Texas Cancer Center randomized clinical trial [NCT01893307] for proton therapy in oropharyngeal cancer. We did notice through the running of that trial that there was reduced lymphopenia, meaning that the white blood cells were able to maintain higher levels throughout the course of treatment with proton therapy compared to photon therapy. It’s still exploratory as to the importance of that with respect to patients during and shortly after their treatment, as well as the ability for the body to surveil for cancer cells in the future. There are data in other disease sites, which also demonstrate that maintaining those white blood cell counts through the course of treatment and beyond does have prognostic significance for patients.
Read full interview: https://www.cancernetwork.com/view/comparing-quality-of-life-outcomes-with-protons-vs-photons-in-opscc
