Adaptive radiotherapy for head and neck cancer: Pitfalls and possibilities from the radiation oncologist's point of view

Abstract

Background: Patients with head and neck cancer (HNC) may experience substantial anatomical changes during the course of radiotherapy treatment. The implementation of adaptive radiotherapy (ART) proves effective in managing the consequent impact on the planned dose distribution.

Methods: This narrative literature review comprehensively discusses the diverse strategies of ART in HNC and the documented dosimetric and clinical advantages associated with these approaches, while also addressing the current challenges for integration of ART into clinical practice.

Results and conclusion: Although based on mainly non-randomized and retrospective trials, there is accumulating evidence that ART has the potential to reduce toxicity and improve quality of life and tumor control in HNC patients treated with RT. However, several questions remain regarding accurate patient selection, the ideal frequency and timing of replanning, and the appropriate way for image registration and dose calculation. Well-designed randomized prospective trials, with a predetermined protocol for both image registration and dose summation, are urgently needed to further investigate the dosimetric and clinical benefits of ART.

Keywords: adaptive radiotherapy; head and neck cancer; review.

FIGURE 1

The workflow of offline and online ART. The labor‐intensive workflow of ART. In an offline setting, a re‐simulation CT is performed, on which new contouring and RT planning are executed. Commercial software for online ART is being introduced, allowing automated dose calculations and adapted planning on CBCT‐based imaging after Deformable Image Registration (D.I.R.).