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

Aim: To investigate the diagnostic performance of early acquisition compared to late imaging for the detection of local recurrence of prostate cancer by means of ¹⁸F-FCH PET/CT. Materials and methods: 99 patients with radical prostatectomy (mean PSA 3.9 ± 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. Results: 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. Conclusions: The combination of early acquisition with late acquisition lead to an increase of the diagnostic accuracy of ¹⁸F-FCH PET/CT for the diagnosis of local recurrence in prostate cancer.