18F-FDG-PET/CT in the diagnosis of paraneoplastic neurological syndromes: a retrospective analysis.
OBJECTIVE
Paraneoplastic neurological syndromes (PNS) constitute a challenging diagnostic problem, as the underlying tumour often remains unidentified for a long time, even with frequent conventional diagnostic procedures. For appropriate patient management timely identification of the tumour is critical. We evaluated the value of (18)F-FDG-PET/CT in the investigation of PNS.


METHODS
The case notes of 46 consecutive patients with clinically suspected PNS who underwent (18)F-FDG-PET/CT were reviewed retrospectively and the performance of PET/CT for detecting underlying tumours was assessed.


RESULTS
PET/CT detected foci of increased (18)F-FDG uptake in 10 out of 46 patients. In six of these 10 patients combined PET/CT identified the underlying disease: four patients suffered from PNS; vasculitic and local metastatic disease was detected in two other patients.


CONCLUSIONS
Based on our results, we believe that the role of positron emission tomography in the detection of occult neoplasms in patients with PNS has been overestimated in the past. In clinical practice, PNS is far more often suspected than proven. In our study combined PET/CT identified malignancy as the underlying cause of suspected PNS in only 8.7% (4/46). We believe that combined PET/CT should be reserved for stringently selected patients with a high clinical index of suspicion for PNS and after conventional imaging techniques fail to detect a tumour.
Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Hamburg-Eppendorf, Germany. p.bannas@uke.uni-hamburg.de
Peter
P
Bannas
Christoph
C
Weber
Thorsten
T
Derlin
Jörg
J
Lambert
Frank
F
Leypoldt
Gerhard
G
Adam
Janos
J
Mester
Susanne
S
Klutmann
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18