Response evaluation after chemoradiotherapy for advanced staged oropharyngeal squamous cell carcinoma: a nationwide survey in the Netherlands.

Following failure of chemoradiotherapy (CRT) for advanced staged oropharyngeal squamous cell carcinomas (OPSCC), residual tumor can often be treated successfully with salvage surgery, if detected early. Current clinical practice in the VU University Medical Center is to perform routine response evaluation, i.e., examination under general anesthesia (EUA), 12 weeks after treatment. However, in the Netherlands there is no consensus on response evaluation in patients with advanced oropharyngeal cancer. Questionnaire on current clinical practice concerning response evaluation after CRT for advanced OPSCC in all eight head and neck cancer centers of the Dutch Head and Neck Oncology Cooperative Group. The response rate was 100%. Response evaluation was routinely performed with various methods in five institutions (62.5%) and in one institute (12.5%) only if clinical evaluation was difficult. Two centers (25%) did not perform response evaluation. In case of suspicion of residual disease during follow-up, six centers (75%) performed imaging prior to EUA and two centers (25%) only if clinical evaluation was difficult. Diagnostic techniques used prior to EUA were MRI (87.5%), diffusion-weighted MRI (37.5%), 18F-FDG-PET-CT (75-87.5%) and CT (37.5%). This survey shows a substantial variation in the diagnostic policy concerning response evaluation after CRT for advanced OPSCC in the Netherlands. There is a need for guidelines for response evaluation in patients with advanced oropharyngeal cancer.