Radiation response non-invasively imaged by [18F]FDG-PET predicts local tumor control and survival in advanced oral squamous cell carcinoma.

It is a major challenge to preoperatively identify patients who will profit from surgery of advanced oral cancer. In multimodality therapy, response to neoadjuvant radiation correlates to treatment success. Hence, for preoperative decisions, assessment of treatment response is required. Therefore, we analysed the prognostic significance of glucose metabolism after preoperative radiotherapy. [(18)F]FDG-PET investigations were performed for re-staging 35 patients after neoadjuvant radiotherapy (36Gy) immediately prior to tumor resection. Emission and transmission measurements were obtained and SUV's were calculated for the sites of maximum [(18)F]FDG-uptake. Subpopulations of "low" (SUV < 4) and "high" (SUV > or = 4) glucose metabolism were compared by univariate and multivariate survival analysis. 3-years survival was 80% in the "low" SUV group and 43% in the "high" SUV group. Post-irradiation [(18)F]FDG-uptake significantly predicts survival (P = 0.046) and local tumor control (P = 0.0017). High [(18)F]FDG-uptake was associated with an increased hazard of death (P = 0.037) and especially of local progress (P = 0.011) even when radical resection was performed. Thus, [(18)F]FDG-PET non invasively identified patients with poor prognosis whose indication for radical surgery has to be considered with caution. Copyright 2002 Elsevier Science Ltd.