Abstract
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Objectives Comparative study of impact/ performance of fluorocholine(18F) (FCH) vs. modern anatomic imaging in the initial staging of prostate cancer (PC).
Methods 79 patients prior to treatment; in 18 cases, PC was only suspected on high serum PSA levels and non-contributive biopsies. The referring urologist was free to choose as comparator the best conventional imaging (CI): contrast-enhanced CT (CECT) or MRI. The written reports of the referring urologist during follow-up of at least 6 months (FU) were used by an independent urologist assessor (IA) to determine the impact of FCH PET/CT on management. To compare diagnostic performance, FCH PET/CT and CI were blind read by NM/radiology specialists respectively. In case of discordant quotation, a consensus was obtained for each modality that formed the basis for performance calculations The standard-of-truth (SOT) was evaluated by IA blinded to the results of FCH and of its comparator: 13 sites were defined; a site was "positive" only if a lesion was malignant at histology or if irradiation of a lesion resulted in a significant drop of PSA; a site was "negative" only if no malignancy was found at histology and during FU with repeated investigations dedicated at its evaluation. Comparison of performance used the Mc Nemar's test.
Results The rate of change in management was 11/79=14% and an impact rate on diagnostic thinking 12/79=15% other patients. SOT could be determined for 195 sites and 59 patients. Patient-based sensitivity of FCH PET/CT vs. CI was 92% vs. 50% n=52; vs. CECT 87% vs. 36% n=31; vs. MRI 100% vs. 71 n=21. FCH> CECT &MRI, all p<0.03. Patient-based specificity 71% vs. 57%; n=7 (NS). Site-based sensitivity of FCH PET/CT vs. CI was 84% vs. 36% n=93; vs. CECT 77% vs. 21 n=57; vs. MRI 94% vs. 59% n=36. FCH> CECT &MRI, all p<0.001. No significant difference in site-based specificity.
Conclusions FCH PET/CT had a 29% impact rate and superior sensitivity as compared to both CECT and MRI.
Research Support Phase II pivotal study sponsored by Iason