Prospective Validation of Adaptive Radiotherapy (ART) in Patients With Head and Neck Tumors

Overview

Adaptive radiotherapy (ART) includes image-guided radiotherapy (IGRT) and also offers further possibilities for plan adaptation. A particularly high benefit can be expected for patients in whom the clinical target volume (CTV) can show a significant change in shape from fraction to fraction due to anatomical deviations. The shape and position constancy of the CTV during the course of the series is examined in this trial. Dosimetric disadvantages of this type have not been reported so far. The aim of this study is to identify patients who benefit from ART at an early stage and to select them for this method, and then to continue to offer ART to this patient group. If a relevant reduction in the minimum planning target volume (PTV) margins with ART compared to IGRT is demonstrated in this study, patients could be treated with ART.

The aim here is to prospectively evaluate modern technical standards. In the last 25 years, radiotherapy has developed rapidly away from two-dimensional procedures towards volume-modulated, three-dimensional techniques. But here, too, there is a broad radiotherapeutic spectrum due to the high technical diversity in radiotherapy and ever newer technical innovations. (1) Definitive radiochemotherapy is standard of care for locally advanced head and neck tumors. The aim of this study is to monitor the influence of the new technical therapy standards (therapy options in application: volume-modulated rapid-arc technique (VMAT) / online onboard image-guidance (IGRT) and adaptive re-planning, using the linear accelerator ETHOS currently established and installed at the Department of Radiotherapy in December 2021) as a function of dose parameters for quality assurance of feasibility. Therapy with ETHOS represents a comprehensive new treatment option that is tailored and individualized from the initial planning and adjustment on the treatment table to radiation monitoring of the whole therapy. Online-adaptive radiotherapy (ART) allows the dose distribution to be adapted to the anatomical changes online and immediately before each radiation fraction. Adaptive radiotherapy is a further development of image-guided radiotherapy (IGRT), which is now standard of care in radiotherapy. In contrast to ART, with IGRT the radiation plan cannot be adapted to deformations of the body from radiation fraction to radiation fraction, e.g. through different positioning of the tongue or jaw. This trial creates the basis for standardizing treatment parameters as far as possible, but also for introducing improvements in the treatment of future patients in a personalized and individualized form. Standard therapy can be further optimized using modern equipment and high-precision linear accelerators.