The therapeutic impact of [F18]‐2‐fluordesoxyglucose PET for the staging and monitoring of oral cancer: a comparative study of PET before and after preoperative radiochemotherapy with CT and histologic data

The lack of sensitivity and specificity of conventional imaging techniques based on morphological criteria is responsible for considerable limitations in the staging and surveillance of oral cancer. Therefore, this study investigated the contribution of [F18]-2-fluordesoxyglucose (FDG) positron emission tomography (PET) to tumour management, with special regard to lymph node involvement and therapeutic monitoring after radiotherapy. In this prospective, observational study, 21 patients with advanced oral cancer, predominantly T3/T4, were evaluated. FDG-PET scans before and after preoperative radio(chemo)therapy were performed and standardized uptake values (SUV) were determined for the tumour site and lymph node areas. PET scans were correlated to histological findings after ablative tumour surgery. FDG-PET yielded superior sensitivity and specificity for tumour and lymph node assessment. The effect of radiotherapy was reflected by the metabolic activity of the tumour, which showed a close correlation with the decrease of FDG uptake and histologic tumour regression. PET detected distant metastases and simultaneous tumours. The authors concluded that FDG-PET is a challenging imaging technique with the potential to improve the staging procedure for oral cancer. In the monitoring of metabolic activity of the tumour in the course of radio(chemo)therapy, FDG-PET allowed objective measurement of the treatment response. H. Schliephake