Study Finds Comparable Outcomes for Intensity-Modulated Radiation Therapy and Proton Therapy in Oropharyngeal Cancer

A recent phase III clinical trial reveals that intensity-modulated radiation therapy (IMRT) and proton beam therapy yield similar quality-of-life results and low side effect rates in treating locally advanced oropharyngeal cancer. Conducted across the United Kingdom, the TORPEdO trial involved 205 patients randomly assigned to receive either proton therapy (136 patients) or IMRT (69 patients) alongside chemotherapy. The primary focus was to evaluate both clinical outcomes and patient-reported experiences over the course of a year.

The findings showed that both treatments achieved excellent tumor control with minimal long-term side effects. At the one-year mark post-treatment, the percentage of patients dependent on feeding tubes was equally low at 1.7% for both groups. While severe weight loss was more common in the proton therapy group (18.2%) versus IMRT (5.7%), overall, there was no statistically significant difference between the two techniques regarding these measures.

Patient self-reported outcomes examining oral functions, swallowing, speech, and appearance also revealed no meaningful differences between the two groups. Quality of life scores and swallowing function measurements were comparable, indicating that both advanced radiation methods are effective from the patient's perspective.

Expert analysis highlighted that the high quality of IMRT performance contributed to these results, with long-term dependence on feeding tubes being notably lower than in past trials. Survival rates—two-year overall survival at around 94-95%—were similarly high, underscoring the efficacy of both approaches.

While proton therapy demonstrated the ability to reduce radiation exposure to critical structures such as salivary glands and swallowing organs, this dosimetric advantage did not translate into measurable benefits in patient-reported outcomes within this study timeframe. Dr. Thomson emphasized that advancements in IMRT have made it a very effective treatment option, providing excellent care accessible at many treatment centers.

The trial's rigorous quality assurance procedures ensured high standards in treatment planning and delivery, supporting the validity of the findings. Overall, the study suggests that high-quality IMRT remains a well-performing, more widely available, and less costly option for managing oropharyngeal cancer, with proton therapy offering no additional measurable benefit in patient-centered outcomes over the first year post-treatment.

Source: https://medicalxpress.com/news/2025-09-intensity-modulated-therapy-proton-oropharyngeal.html