Impact of FDG-PET/CT imaging on nodal staging for head-and-neck squamous cell carcinoma.
OBJECTIVE
To evaluate the impact of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging on nodal staging for head-and-neck squamous cell carcinoma (SCC).


METHODS
The study population consisted of 23 patients with head-and-neck SCC who were evaluated with FDG-PET/CT and went on to neck dissection. Two observers consensually determined the lesion size and maximum standardized uptake value (SUVmax) and compared the results with pathologic findings on nodal-level involvement. Two different observers (A and B) independently performed three protocols for clinical nodal staging. Methods 1, 2, and 3 were based on conventional modalities, additional visual information from FDG-PET/CT images, and FDG-PET/CT imaging alone with SUV data, respectively.


RESULTS
All primary tumors were visualized with FDG-PET/CT. Pathologically, 19 positive and 93 negative nodal levels were identified. The SUVmax overlapped in negative and positive nodes <15 mm in diameter. According to receiver operating characteristics analysis, the size-based SUVmax cutoff values were 1.9, 2.5, and 3.0 for lymph nodes <10 mm, 10-15 mm, and >15 mm, respectively. These cutoff values yielded 79% sensitivity and 99% specificity for nodal-level staging. For Observer A, the sensitivity and specificity in Methods 1, 2, and 3 were 68% and 94%, 68% and 99%, and 84% and 99%, respectively, and Method 3 yielded significantly higher accuracy than Method 1 (p = 0.0269). For Observer B, Method 3 yielded the highest sensitivity (84%) and specificity (99%); however, the difference among the three protocols was not statistically significant.


CONCLUSIONS
Imaging with FDG-PET/CT with size-based SUVmax cutoff values is an important modality for radiation therapy planning.
Murakami
Ryuji
R
Department of Radiation Oncology, Kumamoto University Hospital, Kumamoto, Japan. murakami@kaiju.medic.kumamato-u.ac.jp
Uozumi
Hideaki
H
Hirai
Toshinori
T
Nishimura
Ryuichi
R
Shiraishi
Shinya
S
Ota
Kazutoshi
K
Murakami
Daizo
D
Tomiguchi
Seiji
S
Oya
Natsuo
N
Katsuragawa
Shigehiko
S
Yamashita
Yasuyuki
Y
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000556:secondary; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009367:Neoplasm Staging / Q000379:methods; D015588:Observer Variation; D049268:Positron-Emission Tomography / Q000379:methods*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
D019788:Fluorodeoxyglucose F18