Definitive radiotherapy-based treatment for patients with head and neck cancers is associated with a meaningful toxicity burden. Consequently, it has been a promising site for the improved dosimetry seen with proton therapy. Prospective evidence continues to emerge regarding the role of proton therapy in the treatment of head and neck cancers. The first study of this kind to be presented was presented by Steven Frank, MD, in May 2024 at ASCO. The study randomized patients requiring bilateral neck radiotherapy for oropharyngeal cancers to proton versus IMRT-based therapy. They found proton therapy significantly reduced gastrostomy tube dependence at any time and end-of-treatment weight loss (<5%). Three studies presented this week further add to this evidence base.
 | Presenting author: Edward Dee, MD Nancy Lee, MD, FASTRO, and colleagues from Memorial Sloan Kettering Cancer Center, report on a multi-center American randomized study of patients with salivary gland tumors, skin cancer, melanoma, or tonsil cancer requiring unilateral neck radiation. Edward Dee, MD, Memorial Sloan Kettering Cancer Center, presented the results from “A Phase II Randomized Study of Proton vs. Intensity-Modulated Radiation Therapy in the Treatment of Unilateral Head and Neck Cancer.” Patients were randomized to either proton or IMRT radiotherapy. Patients receiving proton therapy had a significant reduction in acute grade 2+ mucositis and acute grade 2+ dysgeusia with similar overall and progression-free survival between the groups. |
 | Presenting author: Lin Kong, MD Lin Kong, MD, and colleagues from Fudan University Shanghai Cancer Center, Shanghai, report on a Chinese randomized study of proton therapy versus IMRT for patients with nasopharyngeal carcinoma, presenting results from “Proton vs. Photon for Nasopharyngeal Carcinoma: Toxicity and Survival in a Phase 2 Randomized Study.” While they found a numeric reduction in grade 2+ xerostomia at six months among patients treated with proton therapy, this was not statistically significant. |
 | Presenting author: David Thompson, MD In the Plenary Session, David Thompson, MD, and colleagues from The Christie NHS Foundation Trust, Manchester, presented results of the TORPEdO trial from the United Kingdom. This study was similar in design to the study presented by Dr. Frank randomizing patients with locally advanced oropharyngeal squamous cell carcinoma requiring bilateral neck radiation between proton therapy and IMRT. At one year of follow-up, they found no differences in gastrostomy dependence, UW-QOL physical composite score, or MDADI mean composite score. |
Taken together, these three seminal studies in the management of head and neck cancer help guide our understanding of the value of proton therapy in this patient population. Based on the study previously reported by Dr. Frank et al. and the study reported here by Dr. Dee at al., the benefit of proton therapy may be greatest in reducing the acute side effects of treatment. However, the studies by Dr. Kong et al. and Dr. Thompson et al., which evaluated toxicity at 6- and 12-months post-treatment respectively, show no significant change. Optimizing radiotherapy treatment plans remains an ever-evolving challenge in patients with head and neck cancers, and these seminal results will help continue to inform the field how to best do that.
Abstract 241 – A Phase II Randomized Study of Proton vs. Intensity-Modulated Radiation Therapy in the Treatment of Unilateral Head and Neck Cancer was presented in SS 24 - Head and Neck 2: Top-Rated Abstracts in Head & Neck Cancer during ASTRO’s 67th Annual Meeting.
Abstract 244 - Proton vs. Photon for Nasopharyngeal Carcinoma: Toxicity and Survival in a Phase 2 Randomized Study was presented in SS 24 - Head and Neck 2: Top-Rated Abstracts in Head & Neck Cancer during ASTRO’s 67th Annual Meeting.
Abstract LBA 02 - Primary Results for the Phase III Trial of Toxicity Reduction Using Proton Beam Therapy for Oropharyngeal Cancer (Torpedo; CRUK/18/010) was presented in the Plenary Session during ASTRO’s 67th Annual Meeting.
