Clinical value of a combined multi-phase contrast enhanced DOPA-PET/CT in neuroendocrine tumours with emphasis on the diagnostic CT component.

Veit-Haibach, Patrick; Schiesser, Marc; Soyka, Jan; Strobel, Klaus; Schaefer, Niklaus G; Hesselmann, Rolf; Clavien, P-A; Hany, Thomas F

OBJECTIVE To assess the clinical value of multi-phase, contrast-enhanced DOPA-PET/CT with emphasis on the diagnostic CT component in patients with neuroendocrine tumours (NET). METHODS Sixty-five patients with NET underwent DOPA-cePET/CT. The DOPA-PET, multi-phase CT and combined DOPA cePET/CT data were evaluated and diagnostic accuracies compared. The value of ceCT in DOPA cePET/CT concerning lesion detection and therapeutic impact was evaluated. Sensitivities, specificities and accuracies were calculated. Histopathology and clinical follow-up served as the standard of reference. Differences were tested for statistical significance by McNemar's test. RESULTS In 40 patients metastatic and/or primary tumour lesions were detected. Lesion-based analysis for the DOPA-PET showed sensitivity, specificity and accuracy of 66%, 100% and 67%, for the ceCT data 85%, 71% and 85%, and for the combined DOPA cePET/CT data 97%, 71% and 96%. DOPA cePET/CT was significantly more accurate compared with dual-phase CT (p < 0.05) and PET alone (p < 0.05). Additional lesion detection was based on ceCT in 12 patients; three patients underwent significant therapeutic changes based on the ceCT findings. CONCLUSION DOPA cePET/CT was significantly more accurate than DOPA-PET alone and ceCT alone. The CT component itself had a diagnostic impact in a small percentage but contributed to the therapeutic strategies in selected patients.