Distant metastases and synchronous second primary tumors in patients with newly diagnosed oropharyngeal and hypopharyngeal carcinomas: evaluation of (18)F-FDG PET and extended-field multi-detector row CT.
BACKGROUND
Patients with oropharyngeal or hypopharyngeal squamous cell carcinoma (SCC) have a high risk of having distant metastases or second primary tumors. We prospectively evaluate the clinical usefulness of (18)F-fluoro-2-deoxyglucose positron emission tomography ((18)F-FDG PET), extended-field multi-detector computed tomography (MDCT), and their side-by-side visual correlation for the detection of distant malignancies in these two tumors at presentation.


METHODS
A total of 160 patients with SCC of the oropharynx (n = 74) or hypopharynx (n = 86) underwent (18)F-FDG PET and extended-field MDCT to detect distant metastases or second primary tumors. Suspected lesions were investigated by means of biopsy, clinical, or imaging follow-up.


RESULTS
Twenty-six (16.3%) of our 160 patients were found to have distant malignancy. Diagnostic yields of (18)F-FDG PET and MDCT were 12.5% and 8.1%, respectively. The sensitivity of (18)F-FDG PET for detection of distant malignancies was 1.5-fold higher than that of MDCT (76.9% vs. 50.0%, P = 0.039), while its specificity was slightly lower (94.0% vs. 97.8%, P = 0.125). Side-by-side visual correlation of MDCT and (18)F-FDG PET improved the sensitivity and specificity up to 80.8% and 98.5%, respectively, leading to alteration of treatment in 13.1% of patients. A significant difference in survival rates between its positive and negative results was observed.


CONCLUSIONS
(18)F-FDG PET and extended-field MDCT had acceptable diagnostic yields for detection of distant malignancies in untreated oropharyngeal and hypopharyngeal SCC. (18)F-FDG PET was 1.5-fold more sensitive than MDCT, but had more false-positive findings. Their visual correlation improved the diagnostic accuracy, treatment planning, and prognosis prediction.
Ng
Shu-Hang
SH
Department of Molecular Imaging Center and Diagnostic Radiology, Chang Gung Memorial Hospital, Linkou Medical Center, Chang Gung University, Taoyuan, Taiwan.
Chan
Sheng-Chieh
SC
Liao
Chun-Ta
CT
Chang
Joseph Tung-Chieh
JT
Ko
Sheung-Fat
SF
Wang
Hung-Ming
HM
Chin
Shu-Chyn
SC
Lin
Chin-Yu
CY
Huang
Shiang-Fu
SF
Yen
Tzu-Chen
TC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000556:secondary*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016609:Neoplasms, Second Primary / Q000175:diagnosis*; D009959:Oropharyngeal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18