DARTBOARD (STU2021-0401: A Prospective Randomized Phase II Study of Daily Adaptive Radiotherapy to Better Organ-at-Risk Doses in Head and Neck Cancer), an innovative, first-of-its-kind clinical trial, is now complete. This study ran from March 2022 through July 2023 and treated the tightest head and neck cancer volumes to date through daily volume reduction. This daily adaptation accounted for anatomical changes in the patient and the disease while concurrently reducing margins to 1 mm. Importantly, this study was the first to investigate daily adaptive radiotherapy for head and neck cancer patients, with the aim of minimizing toxicity and improving patient-reported outcomes, especially those associated with salivary function. A total of 50 patients with stage I-IVB squamous cell carcinoma of the oropharynx, larynx, or hypopharynx completed the study, with patients randomized to two arms: arm 1 receiving involved nodal radiation therapy, arm 2 receiving near marginless daily adaptive involved nodal radiation therapy.
David Sher, M.D., M.P.H., Professor of Radiation Oncology, Vice Chair of Clinical Operations and Quality, Medical Director, and Chief of Head and Neck Radiation Oncology Service, led this project and recently presented the exciting findings of the study at the American Society for Radiation Oncology (ASTRO) meeting in October. The preliminary data are quite promising, with significantly less acute skin reaction and preliminary signals of improved dry mouth.
Only 8% of patients in the daily adaptive arm developed grade 2 or higher acute dermatitis versus 31% in the standard arm. Patients also experienced less sticky saliva, likely due to a lower dose of radiation being administered to the salivary glands. Patients in both arms did well from a swallowing perspective, with favorable results on the MD Anderson Dysphagia Inventory (MDADI) at six months post-treatment. Treatment delivery time was excellent with this technique as well, with the treatment process taking an average of 33 minutes per patient and with an average door-in to door-out time of 39 minutes. Physicians were also efficient with their replanning, taking an average of 12.6 minutes to contour and 22 minutes at the console for these adaptive radiotherapy cases.
The study results will continue to mature over the next year and Dr. Sher expects the final results in mid-2024. However, even the preliminary data have shown how daily adaptive radiotherapy with reduced margins can improve acute quality-of-life scores.
“Standard radiotherapy paradigms knowingly treat a rim of normal tissue to account for daily setup error, and that naturally leads to an unnecessary dose to important normal organs,” Dr. Sher explains. “But with daily adaptation, there’s almost no radiation targeted to normal-appearing anatomy, and the less uninvolved tissue irradiated, the better for short- and long-term function.”
Reducing setup margins has already appeared to improve quality of life with certain prostate treatments, and if the favorable interim results of DARTBOARD are maintained with additional follow-up, daily adaptive radiotherapy with extremely narrow margins may be expanded to almost any disease site.
David Sher, M.D., M.P.H.
Professor, Vice Chair of Clinical Operations and Quality, Medical Director, and Chief of Head and Neck Radiation Oncology Service