Prospective Evaluation of ¹⁸F-DCFPyL PET/CT in Biochemically Recurrent Prostate Cancer in an Academic Center: A Focus on Disease Localization and Changes in Management

Abstract

18 F-DCFPyL (2-(3-{1-carboxy-5-[(6-18 F-fluoropyridine-3-carbonyl)amino]-pentyl}-ureido)-pentanedioic acid) is a promising PET radiopharmaceutical targeting prostate-specific membrane antigen (PSMA). We present our experience with this single-academic-center prospective study evaluating the positivity rate of 18 F-DCFPyL PET/CT in patients with biochemical recurrence (BCR) of prostate cancer (PC). Methods: We prospectively enrolled 72 men (52-91 y old; mean ± SD, 71.5 ± 7.2) with BCR after primary definitive treatment with prostatectomy (n 5 42) or radiotherapy (n 5 30). The presence of lesions compatible with PC was evaluated by 2 independent readers. Fifty-nine patients had scans concurrent with at least one other conventional scan: bone scanning (24), CT (21), MR (20), 18 F-fluciclovine PET/CT (18), or 18 F-NaF PET (14). Findings from 18 F-DCFPyL PET/CT were compared with those from other modalities. Impact on patient management based on 18 F-DCFPyL PET/CT was recorded from clinical chart review. Results: 18 F-DCFPyL PET/CT had an overall positivity rate of 85%, which increased with higher prostate-specific antigen (PSA) levels (ng/mL): 50% (PSA , 0.5), 69% (0.5 # PSA , 1), 100% (1 # PSA , 2), 91% (2 # PSA , 5), and 96% (PSA $ 5). 18 F-DCFPyL PET detected more lesions than conventional imaging. For anatomic imaging, 20 of 41 (49%) CT or MRI scans had findings congruent with 18 F-DCFPyL, whereas 18 F-DCFPyL PET was positive in 17 of 41 (41%) cases with negative CT or MRI findings. For bone imaging, 26 of 38 (68%) bone or 18 F-NaF PET scans were congruent with 18 F-DCFPyL PET, whereas 18 F-DCFPyL PET localized bone lesions in 8 of 38 (21%) patients with negative results on bone or 18 F-NaF PET scans. In 8 of 18 (44%) patients, 18 F-fluciclovine PET had located the same lesions as did 18 F-DCFPyL PET, whereas 5 of 18 (28%) patients with negative 18 F-fluciclovine findings had positive 18 F-DCFPyL PET findings and 1 of 18 (6%) patients with negative 18 F-DCFPyL findings had uptake in the prostate bed on 18 F-fluciclovine PET. In the remaining 4 of 18 (22%) patients, 18 F-DCFPyL and 18 F-fluciclovine scans showed different lesions. Lastly, 43 of 72 (60%) patients had treatment changes after 18 F-DCFPyL PET and, most noticeably, 17 of these patients (24% total) had lesion localization only on 18 F-DCFPyL PET, despite negative results on conventional imaging. Conclusion: 18 F-DCFPyL PET/CT is a promising diagnostic tool in the work-up of biochemically recurrent PC, given the high positivity rate as compared with Food and Drug Administration-approved currently available imaging modalities and its impact on clinical management in 60% of patients.

Clinical impact of PSMA PET in biochemically recurrent prostate cancer; a review of the literature

“…Ultimately 16 studies were included in the review (Tab. 2; [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]). Twelve studies reported outcomes using [ 68 Ga]-PSMA-11 PET, while four studies reported data on other PSMA-tracers.…”

“…A similar study by Song et al used the promising 18 F-labelled tracer 18 F-DCFPyL. They reported change of management in 43/72 patients (60%) in a heterogenous population of patients after RP and radiation therapy with BCR [35]. A study by Schmidt-Hegeman et al primarily investigated the effect of [ 68 Ga]-PSMA-11 PET/CT guided radiation therapy on the biochemical recurrence free survival.…”

Multiparametric MRI and 18F-DCFPyL PET/CT for Detection of Locally Recurrent Prostate Cancer After Low dose Rate Brachytherapy

“…Multiple studies have con rmed a high detection rate of recurrent PCa with various PSMA-targeting radiotracers even in biochemical recurrence patients with low PSA levels, and usually exceeds mpMRI (27)(28)(29). Some studies suggest a strong correlation between PSA levels and diagnostic performance of PSMA-targeting PET tracers (27)(28)(29)(30)(31). Our small sample size cohort did not allow for such a correlation, however in a future study with a larger cohort, imaging results should be correlated with PSA levels to test whether this holds true in patients who have undergone brachytherapy.…”

Multiparametric MRI and 18F-DCFPyL PET/CT for detection of locally recurrent prostate cancer after low dose rate brachytherapy

“…Multiple studies have con rmed a high detection rate of recurrent PCa with various PSMA-targeting radiotracers even in biochemical recurrence patients with low PSA levels, and usually exceeds mpMRI (28)(29)(30). Some studies suggest a strong correlation between PSA levels and diagnostic performance of PSMA-targeting PET tracers (28)(29)(30)(31)(32). Our small sample size cohort did not allow for such a correlation, however in a future study with a larger cohort, imaging results should be correlated with PSA levels to test whether this holds true in patients who have undergone brachytherapy.…”