Role of ¹⁸F-FCH PET/CT in Detecting Recurrences of Prostate Cancer After Curative Treatments

To evaluate the role of ¹⁸F-fluorocholine (¹⁸F-FCH) positron emission tomography/computed tomography (PET/CT) in prostate cancer (PC) patients with biochemical recurrence who were submitted to different curative treatments.

Seventy-five patients with PC who underwent ¹⁸F-FCH PET/CT for biochemical recurrence were retrospectively analyzed to distinguish patients who were submitted only to prostatectomy (PR group), only to radiotherapy (RT) on prostate with curative intent (RT group), and to both (PR + RT group). Correlations between ¹⁸F-FCH PET/CT and outcome and between prostate-specific antigen (PSA) values and sites and the number of metastases were analyzed. The performance of ¹⁸F-FCH PET/CT in relation to the PSA value and of maximum standardized uptake value (SUV_max) value in relation to patient outcome were assessed by receiver operating characteristic (ROC) curves.

¹⁸F-FCH PET/CT relapses mostly involved lymph nodes, bones, and prostate bed. K-cohen test showed moderate agreement with the outcome in the whole population and in the PR group, whereas in the RT group it was perfect and in PR + RT fair. A statistically significant difference in PSA values was observed in the presence of lymph node metastases and with multiple metastases. ROC curves showed PSA cut-off values of 1.96 ng/dL, 1.95, 1.81, and 2.96, respectively, in the whole population, PR, RT and PR + RT group. SUV_max cut-off values of 3.75, 3.45, and 4.7 were described in the whole population, PR group, and PR + RT group.

The study confirms that ¹⁸F-FCH PET/CT is still valid in PC patients with suspected biochemical recurrence. Therefore, we can affirm that it still makes sense to perform it both with high PSA values and with lower values when prostate-specific membrane antigen tracers are not available.