Early lesion detection with 18F-DCFPyL PET/CT in 248 patients with biochemically recurrent prostate cancer

PurposeProstate-specific membrane antigen (PSMA) PET/CT is increasingly used in patients with biochemically recurrent prostate cancer (BCR), mostly using gallium-68 (Ga-168)-labelled radiotracers. Alternatively, fluorine-18 (F-18)-labelled PSMA tracers are available, such as F-18-DCFPyL, which offer enhanced image quality and therefore potentially increased detection of small metastases. In this study we evaluate the lesion detection efficacy of F-18-DCFPyL PET/CT in patients with BCR and determine the detection efficacy as a function of their PSA value.MethodsA total of 248 consecutive patients were evaluated and underwent scanning with F-18-DCFPyL PET/CT for BCR between November 2016 and 2018 in two hospitals in the Netherlands. Patients were examined after radical prostatectomy (52%), external-beam radiation therapy (42%) or brachytherapy (6%). Imaging was performed 120min after injection of a median dose of 311MBq F-18-DCFPyL.ResultsIn 214 out of 248 PET/CT scans (86.3%), at least one lesion suggestive of cancer recurrence was detected (positive scan'). Scan positivity increased with higher PSA values: 17/29 scans (59%) with PSA values <0.5ng/ml; 20/29 (69%) with PSA 0.5 to<1.0ng/ml; 35/41 (85%) with PSA 1.0 to<2.0ng/ml; 69/73 (95%) with PSA 2.0 to<5.0ng/ml; and 73/76 (96%) with PSA >= 5.0ng/ml. Interestingly, suspicious lesions outside the prostatic fossa were detected in 39-50% of patients with PSA <1.0ng/ml after radical prostatectomy (i.e. candidates for salvage radiotherapy).Conclusion(18)F-DCFPyL PET/CT offers early detection of lesions in patients with BCR, even at PSA levels <0.5ng/ml. These results appear to be comparable to those reported for Ga-68-PSMA and F-18-PSMA-1007, with potentially increased detection efficacy compared to Ga-68-PSMA for patients with PSA <2.0.