Comparison of choline influx from dynamic ¹⁸F-Choline PET/CT and clinicopathological parameters in prostate cancer...

The aim of the study was to compare the kinetic analysis of ¹⁸F-labeled choline (FCH) uptake with static analysis and clinicopathological parameters in patients with newly diagnosed prostate cancer (PC).

Sixty-one patients were included. PSA was performed few days before FCH PET/CT. Gleason scoring (GS) was collected from systematic sextant biopsies. FCH PET/CT consisted in a dual phase: early pelvic list-mode acquisition (from 0 to10 min post-injection) and late whole-body acquisition (60 min post-injection). PC volume of interest was drawn using an adaptative thresholding (40% of the maximal uptake) on the late acquisition and projected onto an early static frame of 10 min and each of the 20 reconstructed frames of 30 s. Kinetic analysis was performed using an imaging-derived plasma input function. Early kinetic parameter (K1 as influx) and static parameters (early SUVmean, late SUVmean, and retention index) were extracted and compared to clinicopathological parameters.

K1 was significantly, but moderately correlated with early SUVmean (r = 0.57, p < 0.001) and late SUVmean (r = 0.43, p < 0.001). K1, early SUVmean, and late SUVmean were moderately correlated with PSA level (respectively, r = 0.36, p = 0.004; r = 0.67, p < 0.001; r = 0.51, p < 0.001). Concerning GS, K1 was higher for patients with GS ≥ 4 + 3 than for patients with GS < 4 + 3 (median value 0.409 vs 0.272 min^- 1, p < 0.001). No significant difference was observed for static parameters.

FCH influx index K1 seems to be related to GS and could be a non-invasive tool to gain further information concerning tumor aggressiveness.