Detection of local recurrence of prostate cancer after radical prostatectomy: Is there a role for early 18F-FCH PET/CT?

To investigate the diagnostic performance of early acquisition compared to late imaging for the detection of local recurrence of prostate cancer by means of F-18-FCH PET/CT. 99 patients with radical prostatectomy (mean PSA 3.9 +/- A 5.03) were subjected to early dynamic PET/CT acquisition of the pelvis and a whole body PET/CT in the same exam session. None of the patients examined was subjected to radiotherapy for local or distant recurrence. All the subjects were taken off hormonal therapy. 58 subjects did not show local recurrence in both early and late acquisition, 22 were positive in both modalities, 10 showed a positive early and a negative late acquisition while 9 showed a negative early and a positive late acquisition (Cohen's k = 0.558). When the results of imaging modalities were considered separately, sensitivity, specificity, positive predictive value and negative predictive value resulted: 78.9, 96.7, 93.8 and 88.1 % for early acquisition and 73.7, 95.1, 90.3 and 85.3 % for late acquisition, respectively. When the results of early and late acquisition were considered together, results were 97.4, 93.4, 90.2 and 98.3 %, respectively. The combination of early acquisition with late acquisition lead to an increase of the diagnostic accuracy of F-18-FCH PET/CT for the diagnosis of local recurrence in prostate cancer.