A randomized trial of PET scanning to improve diagnostic yield of direct laryngoscopy in patients with suspicion of recurrent laryngeal carcinoma after radiotherapy

The RELAPS study (REcurrent LAryngeal carcinoma PET Study) was designed to determine whether FDG–PET is of value in the selection of patients for direct laryngoscopy under general anesthesia in patients with suspicion of recurrent laryngeal carcinoma after radiotherapy. In a randomized controlled clinical trial the current diagnostic practice, i.e. all patients undergo direct laryngoscopy, will be compared to a strategy in which FDG–PET selects the patients for laryngoscopy. All eight head and neck cancer centers of the Dutch Head and Neck Oncology Cooperative Group NWHHT will participate in this multicenter trial. The study population consists of patients with clinical suspicion of recurrent T2–T4 laryngeal carcinoma after radiotherapy (without obvious signs of tumor) in whom a direct laryngoscopy under general anesthesia with taking of biopsies is indicated by the local physician. The primary efficacy endpoint is the difference in the number of futile indications for direct laryngoscopy between the conventional diagnostic arm and the FDG–PET based diagnostic arm. An indication for laryngoscopy is classified as futile if this laryngoscopy was negative and no recurrence was diagnosed within 6 months follow-up (gold standard). The FDG–PET based strategy may increase the risk of missing recurrent tumor compared to current practice. Safety endpoints include survival and morbidity due to laryngoscopy with taking of biopsies. Survival rates of both groups will have to be collected outside the time frame of the funded trial. Resectability of recurrent tumor and tumor negative surgical margins after total laryngectomy will be used as proxy endpoints. The trial will also compare quality of life and direct medical costs between both arms.