2-Deoxy-2[F-18]FDG-PET for detection of recurrent laryngeal carcinoma after radiotherapy: interobserver variability in reporting.
OBJECTIVE
To evaluate accuracy and interobserver variability in the assessment of 2-deoxy-2[F-18]fluoro-D-glucose-positron emission tomography (FDG-PET) for detection of recurrent laryngeal carcinoma after radiotherapy.


METHODS
Eleven experienced nuclear physicians from eight centres assessed 30 FDG-PET scans on the appearance of local recurrence (negative/equivocal/positive). Conservative (equivocal analysed as negative) and sensitive (equivocal analysed as positive) assessment strategies were compared to the reference standard (recurrence within 6months after PET).


RESULTS
Seven patients had proven recurrences. For the conservative and sensitive strategy, the mean sensitivity was 87% and 97%, specificity 81% and 63%, positive predictive values 61% and 46% and negative predictive values 96% and 99%, respectively. Interobserver variability showed a reasonable relation in comparison to the reference standard (kappa = 0.55).


CONCLUSIONS
FDG-PET has acceptable interobserver agreement and yields good negative predictive value for detection of recurrent laryngeal carcinoma. It could therefore be used as first diagnostic step and may reduce futile invasive diagnostics.
van der Putten
L
L
Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
Hoekstra
O S
OS
de Bree
R
R
Kuik
D J
DJ
Comans
E F I
EF
Langendijk
J A
JA
Leemans
C R
CR
D019788:Fluorodeoxyglucose F18; D006801:Humans; D007822:Laryngeal Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D015588:Observer Variation; D049268:Positron-Emission Tomography; D012680:Sensitivity and Specificity
D019788:Fluorodeoxyglucose F18