18F-DCFBC Prostate-Specific Membrane Antigen–Targeted PET/CT Imaging in Localized Prostate Cancer

Abstract

PURPOSE To assess the ability of (N-[N-[(S)-1,3-dicarboxypropyl]carbamoyl]-4-18F-fluorobenzyl-L-cysteine) (18F-DCFBC), a prostate specific membrane antigen (PSMA) targeted positron emission tomography (PET) agent, to detect localized prostate cancer lesions in correlation with multi-parametric MRI (mpMRI) and histopathology. METHODS This HIPAA compliant, prospective IRB approved study included 13 evaluable patients with localized prostate cancer (median age=62.8 years [range 51–74], median PSA=37.5ng/dl [range 3.26–216]. Patients underwent mpMRI and 18F-DCFBC PET/CT within a 3 months’ window. Lesions seen on mpMRI were biopsied under TRUS/MRI fusion guidance or a radical prostatectomy was performed. 18F-DCFBC PET/CT and mpMRI were evaluated blinded and separately for tumor detection on a lesion basis. For PET image analysis MRI and 18F-DCFBC PET images were fused by using software registration and imaging findings were correlated with histology and uptake of 18F-DCFBC in tumors was compared with uptake in benign prostatic hyperplasia (BPH) nodules and normal peripheral zone (PZ) tissue using the 80% threshold maximum standardized uptake value (SUVmax). RESULTS A total of 25 tumor foci (mean size=1.8cm; median size=1.5cm; range=0.6–4.7cm) were histopathologically identified in 13 patients. Sensitivity of 18F-DCFBC PET/CT and mpMRI were 36% and 96%, respectively for all tumors. For index lesions, the largest tumor with highest Gleason score, sensitivity of 18F-DCFBC PET/CT and mpMRI were 61.5% and 92%, respectively. The average SUVmax for primary prostate cancer was higher (5.8±4.4) than that of BPH nodules (2.1±0.3), or than normal prostate tissue (2.1±0.4), at 1 hour p.i. (p=0.0033). CONCLUSION The majority of index prostate cancers are detected with 18F-DCFBC PET/CT and this may be a prognostic indicator based on uptake and staging. However, for detecting prostate cancer with high sensitivity, it is important to combine PSMA PET/CT with mpMRI.

Keeping up with the prostate-specific membrane antigens (PSMAs): an introduction to a new class of positron emission tomography (PET) imaging agents

“…Currently, more studies have been published with 18 F-DCFBC than 18 F-DCFPyL. Turkbey et al ( 4 ), showed that localized PCas were detected by 18 F-DCFBC and mpMRI and these lesions were subsequently validated with MRI/transrectal ultrasound guided biopsy or radical prostatectomy. Tumor uptake was noted to be very high with maximum standardized uptake values (SUV max ) greater than 100 in some lesions 1 and 2 h post-injection ( 50 ).…”

“…Tumor uptake was noted to be very high with maximum standardized uptake values (SUV max ) greater than 100 in some lesions 1 and 2 h post-injection ( 50 ). The method was highly sensitive for intermediate and high-grade primary cancers ( 4 ) ( Figure 2 ). 18 F-DCFPyL PET uptake, was contingent on higher Gleason pattern 4 within tumors, whereas lower-grade PCa with Gleason pattern 3 tended to have much lower radiotracer uptake ( 52 ) ( Figure 3 ) ( 2 ).…”

“…In the BCR setting, Turkbey et al ( 4 ) demonstrated that 18 F-DCFBC could detect recurrences (either local or lymph node) in 60.3% of patients without evidence of disease on conventional imaging ( Figure 4 ). Imaging detection rate correlated to PSA values with a threshold PSA of 0.78 ng/mL or above, highly predictive of a positive scan.…”

“…Its coding domain is usually expressed in patients with clinically significant prostate cancer (PCa) and its over-expression on the cell membrane of prostatic epithelial cells has been shown to be a sensitive biomarker of aggressive disease. PSMA expression increases with both increasing stage and tumor grade and its radiolabeling has been investigated in a variety of PCa settings including local staging, metastasis, biochemical recurrence (BCR), and image-guided interventions ( 2 - 4 ).…”

Detection and Local Staging of Prostate Cancer by 68Ga-PSMA-PET/CT, Comparison with mpMRI and Histopathology

“…Besides Ga68-PSMA, there are other PSMA bound tracers: a study of Turkbey et al with 18F-DCFBC-PET/CT showed a sensitivity of only 61% while mpMRI performed really well (92%) [23]. A study with 18F-PSMA-1007-PET/CT, showed good diagnostic accuracy compared to mpMRI (75% and 73% respectively) [24].…”