Background: The purpose of this study was to compare outcomes among patients treated by intensity-modulated radiotherapy (IMRT) with daily image-guided radiotherapy (IGRT) for head and neck cancer according to the margins used to expand the clinical target volume (CTV) to create a planning target volume (PTV).
Methods: Three hundred sixty-seven consecutive patients were treated with IMRT for squamous cell carcinoma of the head and neck. The first 103 patients were treated with 5-mm CTV-to-PTV margins. The subsequent 264 patients were treated using reduced (3 mm) margins.
Results: The 3-year locoregional control for patients treated using 5-mm and 3-mm CTV-to-PTV margins, respectively, was 78% and 80% (p = .75). The incidence of gastrostomy-tube dependence at 1 year was 10% and 3%, respectively (p = .001). The incidence of posttreatment esophageal stricture was 14% and 7%, respectively (p = .01).
Conclusion: The use of reduced (3 mm) CTV-to-PTV margins was associated with reduced late toxicity while maintaining locoregional control.
Keywords: head and neck cancer; image-guided radiotherapy; intensity-modulated radiotherapy; marginal misses; planning target volume.
© 2014 Wiley Periodicals, Inc.