Improvement in Dysphagia Outcomes Following Clinical Target Volume Reduction in the De-ESCALaTE Study

Area of Science:

• Radiation Oncology
• Head and Neck Cancer
• Clinical Trial Analysis

Background:

• The De-ESCALaTE study demonstrated an overall survival advantage for cisplatin chemotherapy with radiotherapy versus cetuximab in low-risk oropharyngeal cancer.
• A protocol amendment allowed a shift from anatomical to volumetric radiotherapy contouring, impacting the high-dose clinical target volume (CTV).

Purpose of the Study:

• To evaluate the impact of a radiotherapy contouring protocol amendment on toxicity and tumor control in oropharyngeal cancer.
• To compare outcomes between anatomical and volumetric contouring protocols within the De-ESCALaTE trial.

Main Methods:

• Retrospective analysis of 327 patients from the De-ESCALaTE trial, comparing anatomical (n=185) and volumetric (n=142) contouring protocols.
• Tumor control assessed by overall survival and recurrence at 2 years.
• Toxicity evaluated by severe (grades 3-5) and all-grade acute and late toxicities; quality of life and swallowing assessed using EORTC-C30 and MD Anderson Dysphagia Inventory.

Main Results:

• No significant differences in overall survival, recurrence rates, or acute/late toxicity between the anatomical and volumetric contouring protocols.
• Quality of life showed no sustained significant differences between the groups.
• Volumetric contouring demonstrated significant improvements in multiple domains of the MD Anderson Dysphagia Inventory at 1 and 2 years compared to anatomical contouring.

Conclusions:

• Reducing the clinical target volume (CTV) through volumetric contouring in oropharyngeal cancer radiotherapy is associated with improved long-term swallowing function.
• This unplanned post-hoc analysis suggests potential benefits of reduced CTV, warranting further investigation in prospective studies.