Prognostic value of FDG-PET in patients with oropharyngeal carcinoma treated with concurrent chemoradiotherapy

Purpose: The purpose of this study was to evaluate the predictive value of 2-deoxy-2-[F-18] fluoro-D-glucose-positron emission tomography (FDG-PET) following concurrent chemoradiotherapy (CRT) on survival in patients with carcinoma of the oropharynx (OPC). Methods: Eighteen patients with primary OPC who underwent PET pre- and post-CRT were evaluated prospectively for survival. The prognostic performance of post- CRT PET and CT for recurrence was compared. Results: Patients with positive post- CRT PET exhibited significantly lower 2- year cause-specific survival and disease-free survival (50% vs. 91%, P < 0.05 and 0% vs. 83%, P < 0.0001); however, patients with positive post- CRT CT did not exhibit any significant difference (67% vs. 83%, P= 0.416 and 50% vs. 75%, P= 0.070). Other factors, such as clinical and pre- CRT PET variables, also did not indicate any significant difference. The accuracy of prediction of residual and local recurrence for post-CRT PET and CT (local%/regional%) was 83%/94% and 83%/78%, respectively. Conclusion: OPC patients with positive post- CRT PET exhibit poor survival. The prognostic accuracy of post- CRT PET is superior to that of CT. The results of post- CRT FDG-PET should be included in the management of the OPC patients.