The Role of [18F]Fluciclovine PET/CT in the Characterization of High-Risk Primary Prostate Cancer: Comparison with [11C]Choline PET/CT and Histopathological Analysis

Abstract

The primary aim of the study was to evaluate the role of [18F]Fluciclovine PET/CT in the characterization of intra-prostatic lesions in high-risk primary PCa patients eligible for radical prostatectomy, in comparison with conventional [11C]Choline PET/CT and validated by prostatectomy pathologic examination. Secondary aims were to determine the performance of PET semi-quantitative parameters (SUVmax; target-to-background ratios [TBRs], using abdominal aorta, bone marrow and liver as backgrounds) for malignant lesion detection (and best cut-off values) and to search predictive factors of malignancy. A six sextants prostate template was created and used by PET readers and pathologists for data comparison and validation. PET visual and semi-quantitative analyses were performed: for instance, patient-based, blinded to histopathology; subsequently lesion-based, un-blinded, according to the pathology reference template. Among 19 patients included (mean age 63 years, 89% high and 11% very-high-risk, mean PSA 9.15 ng/mL), 45 malignant and 31 benign lesions were found and 19 healthy areas were selected (n = 95). For both tracers, the location of the “blinded” prostate SUVmax matched with the lobe of the lesion with the highest pGS in 17/19 cases (89%). There was direct correlation between [18F]Fluciclovine uptake values and pISUP. Overall, lesion-based (n = 95), the performance of PET semiquantitative parameters, with either [18F]Fluciclovine or [11C]Choline, in detecting either malignant/ISUP2-5/ISUP4-5 PCa lesions, was moderate and similar (AUCs ≥ 0.70) but still inadequate (AUCs ≤ 0.81) as a standalone staging procedure. A [18F]Fluciclovine TBR-L3 ≥ 1.5 would depict a clinical significant lesion with a sensitivity and specificity of 85% and 68% respectively; whereas a SUVmax cut-off value of 4 would be able to identify a ISUP 4-5 lesion in all cases (sensitivity 100%), although with low specificity (52%). TBRs (especially with threshold significantly higher than aorta and slightly higher than bone marrow), may be complementary to implement malignancy targeting.

[18F]fluciclovine vs. [18F]fluorocholine Positron Emission Tomography/Computed Tomography: A Head-to-Head Comparison for Early Detection of Biochemical Recurrence in Prostate Cancer Patients

“…[ 18 F]fluciclovine is a synthetic amino acid absorbed via the L-type amino acid transporter (LAT1) and the sodium-dependent neutral amino acid transporter (ASCT2), up-regulated in many human cancers, including PCa [ 11 ].…”

18F-Fluoroethylcholine PET/CT Radiomic Analysis for Newly Diagnosed Prostate Cancer Patients: A Monocentric Study

“…The role of semiquantitative 18 F-FECh PET/CT parameters is controversial in initial PC staging. Zanoni et al showed a significant correlation between TBR and the International Society of Urological Pathology Score (derived from GS), using the liver as the reference organ [ 12 ]. These data are discrepant with our results, at least partially owing to the fact that we used the spleen as the reference organ.…”

“…Semiquantitative PET parameters were revealed to be useful for significantly discriminate malignant vs. non-malignant lesions [ 12 ]. Schaefferkotter et al showed that SUV could be a strong predictor of aggressive disease in the prostate (GS ≥ 4 + 3) [ 15 ].…”

Role of molecular imaging in the detection of localized prostate cancer

“… 26 , 27 Additional studies suggest that fluciclovine and [ 11 C]choline have similar sensitivity and specificity for the detection of the primary prostate cancer. 28 The most rigorous study evaluating the potential use of fluciclovine PET/CT for detection of primary prostate cancer was the FLUCIPRO trial, a prospective clinical trial which demonstrated a PET/CT sensitivity of 87% with a specificity of 56%. 29 A quantitative analysis of the findings of this study found that the maximum standardized uptake value (SUV max ) was significantly higher for those with clinically significant prostate cancer when compared with those with Gleason 3 + 3 = 6 prostate cancer.…”