18F-Fluorodeoxyglucose-PET/CT to evaluate tumor, nodal disease, and gross tumor volume of oropharyngeal and oral cavity cancer: comparison with MR imaging and validation with surgical specimen.
BACKGROUND
The purpose of this paper is to evaluate the impact of adding combined 18F-PET/CT to MRI for T and N staging of the oral and oropharyngeal cancer and calculation of the gross tumor volume (GTV) having histopathology as reference standard.


METHODS
PET/CT and MRI were performed in 66 patients with suspected oral and oropharyngeal cancer (41 primary tumors/25 recurrent tumors) and nodal disease (114 nodes). Statistical analysis included the McNemar test, sensitivity, specificity for the diagnostic modalities as well as regression analysis, and Bland-Altman graphs for calculated tumor volumes.


RESULTS
There was no statistically significant difference between the two modalities compared to pathological findings regarding detection of disease (P > or =0.72). The sensitivity/specificity for tumor detection were 100/80% and 96.72/60% for MRI and PET/CT, respectively. The sensitivity/specificity for nodal metastases were 88.46/75% and 83.81/73.91% for MRI and PET/CT, respectively. In 18% of cases, the MRI-based T staging resulted in an overestimation of the pathologic tumor stage. The corresponding rate for PET/CT was 22%. Regarding the treated necks, both modalities showed 100% sensitivity for detection of the recurrent lesions. In necks with histologically N0 staging, MRI and PET/CT gave 22% and 26% false positive findings, respectively. The mean tumor volume in the pathologic specimen was 16.6 +/- 18.6 ml, the mean volume derived by the MR imaging was 17.6 +/- 19.1 ml while the estimated by PET/CT volume was 18.8 +/- 18.1 ml (P < or =0.007 between the three methods). The Bland-Altman analysis showed a better agreement between PET/CT and MRI.


CONCLUSIONS
The diagnostic performance of FDG-PET/CT in the local staging of oral cancer is not superior to MRI.
Seitz
Oliver
O
Department of Oromaxillofacial Surgery, JW Goethe University, Frankfurt, Germany.
Chambron-Pinho
Nicole
N
Middendorp
Markus
M
Sader
Rober
R
Mack
Martin
M
Vogl
Thomas J
TJ
Bisdas
Sotirios
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008207:Lymphatic Metastasis / Q000175:diagnosis / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000473:pathology; D009367:Neoplasm Staging; D009959:Oropharyngeal Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D049268:Positron-Emission Tomography / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
D019788:Fluorodeoxyglucose F18