Dynamic (11)C-Choline PET / CT for the primary diagnosis of prostate cancer

OBJECTIVES: To test the ability of dynamic (11)C-PET / CT to discriminate cancerous tissue from background tissue in patients with localized prostate cancer. MATERIALS AND METHODS: Twenty-four consecutive patients with prostate cancer were prospectively evaluated with dynamic (11)C-choline PET / CT prior to radical prostatectomy. The PET / CT scan was divided into 18 sequences of 5 seconds each, followed by 9 sequences of 60 seconds each. Whole-mount sections of harvested prostates served as reference standards. Volumes of interest were positioned on the dynamic PET / CT images and the following quantitative variables were calculated: perfusion coefficient (K1), washout constant (K2), area under the curve (AUC) at 175 and 630 seconds, and average and maximum standardized uptake values (SUV(avg), and SUV(max)). Wilcoxon signed-ranks test was used to compare benign and cancerous areas of the prostate. RESULTS: Areas of cancerous tissue were characterized by higher SUV(avg) and SUV(max) than areas of benign tissue (3.67 ± 2.7 vs. 2.08 ± 1.3 and 5.91 ± 4.4 vs. 3.71 ± 3.7, respectively, P < 0.001), in addition to a higher K1 (0.95 ± 0.58 vs. 0.43 ± 0.24, P < 0.001) and greater cumulative tracer uptake, represented by the AUC at 175 and 630 seconds (P <0.001). No associations were found between dynamic parameters and preoperative prostate specific antigen level or Gleason score. CONCLUSIONS: In this pilot study, (11)C-choline PET / CT demonstrated increased tracer uptake with higher values of static and dynamic parameters in areas of prostate cancer compared to areas of benign tissue. Larger studies are warranted to validate these results and examine the potential applicability of (11)C-choline dynamic PET / CT for the diagnosis of prostate cancer.