The value of 18F-fluorodeoxyglucose-positron emission tomography/ computed tomography (18F- FDG PET/CT) in the staging and impact on the management of patients with nasopharyngeal carcinoma

Abstract

This study sought to prospectively evaluate the influence of contrasted fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDGPET/CT) in the staging of and impact on the management plan for treatment in patients with nasopharyngeal carcinoma (NPC). A total of 14 histologically proven NPC patients (mean age: 44.64±4.01years) were included in the study. These patients underwent contrasted Computed Tomography (CT) as well as 18F-FDGPET/CT imaging. Staging was based on the 7th edition of the American Joint Committee on Cancer Tumor Node Metastases (AJCC-TNM) recommendations. The oncologist was asked to prospectively assign a treatment plan for all patients being evaluated by CT and 18F-FDGPET/CT. The treatment plans were compared with the incremental information supplied by the FDG-PET/CT. The maximum standardised uptake value (SUVmax) and the widest dimension of the primary tumour, cervical lymph nodes size and the distant metastatic lesions were quantified on the co-registered PET/CT images by two experienced nuclear radiologists. The contrasted 18F-FDGPET/CT changed the management intent in nine patients (64.7%). A univariate analysis showed that there were significant correlations between SUVmax and the size of the metastatic lymph nodes (R2 =0.0761, p<0.01), lymph node volume (R2=0.695, p<0.01) and the T-stage (R2=0.647, p<0.01). Multiple linear regression analysis revealed the tumour SUVmax to be the independent predictor of the T-stage (adjusted R2=0.889, p<0.05). The SUVmax may potentially be a surrogate marker for the T-stage in the NPC patients. The use of the combined imaging modality, 18F-FDGPET/CT, substantially impacted on the management strategy for treatment of NPC patients