A PET/MRI study towards finding the optimal [18F]Fluciclovine PET protocol for detection and characterisation of primary prostate cancer.
OBJECTIVE
[18F]Fluciclovine PET imaging shows promise for the assessment of prostate cancer. The purpose of this PET/MRI study is to optimise the PET imaging protocol for detection and characterisation of primary prostate cancer, by quantitative evaluation of the dynamic uptake of [18F]Fluciclovine in cancerous and benign tissue.


METHODS
Patients diagnosed with high-risk primary prostate cancer underwent an integrated [18F]Fluciclovine PET/MRI exam before robot-assisted radical prostatectomy with extended pelvic lymph node dissection. Volumes-of-interest (VOIs) of selected organs (prostate, bladder, blood pool) and sub-glandular prostate structures (tumour, benign prostatic hyperplasia (BPH), inflammation, healthy tissue) were delineated on T2-weighted MR images, using whole-mount histology samples as a reference. Three candidate windows for optimal PET imaging were identified based on the dynamic curves of the mean and maximum standardised uptake value (SUVmeanand SUVmax, respectively). The statistical significance of differences in SUV between VOIs were analysed using Wilcoxon rank sum tests (p<0.05, adjusted for multiple testing).


RESULTS
Twenty-eight (28) patients [median (range) age: 66 (55-72) years] were included. An early (W1: 5-10 minutes post-injection) and two late candidate windows (W2: 18-23; W3: 33-38 minutes post-injection) were selected. Late compared with early imaging was better able to distinguish between malignant and benign tissue [W3, SUVmean: tumour vs. BPH 2.5 vs. 2.0 (p<0.001), tumour vs. inflammation 2.5 vs. 1.7 (p<0.001), tumour vs. healthy tissue 2.5 vs. 2.0 (p<0.001); W1, SUVmean: tumour vs. BPH 3.1 vs. 3.1 (p=0.771), tumour vs inflammation 3.1 vs. 2.2 (p=0.021), tumour vs. healthy tissue 3.1 vs. 2.5 (p<0.001)] as well as between high-grade and low/intermediate-grade tumours (W3, SUVmean: 2.6 vs. 2.1 (p=0.040); W1, SUVmean: 3.1 vs. 2.8 (p=0.173)). These differences were relevant to the peripheral zone, but not the central gland.


CONCLUSIONS
Late-window [18F]Fluciclovine PET imaging shows promise for distinguishing between prostate tumours and benign tissue and for assessment of tumour aggressiveness.
Deparment of Circulation and Medical Imaging, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Mail MTFS*3.1313, POBox 8905, N-7491, Trondheim, Norway. mattijs.elschot@ntnu.no.
Mattijs
http://orcid.org/0000-0002-8056-9103
M
Elschot
Deparment of Circulation and Medical Imaging, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Mail MTFS*3.1313, POBox 8905, N-7491, Trondheim, Norway.|St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
Kirsten M
KM
Selnæs
Deparment of Circulation and Medical Imaging, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Mail MTFS*3.1313, POBox 8905, N-7491, Trondheim, Norway.
Elise
E
Sandsmark
Deparment of Circulation and Medical Imaging, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Mail MTFS*3.1313, POBox 8905, N-7491, Trondheim, Norway.|Department of Radiology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
Brage
B
Krüger-Stokke
Department of Pathology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
Øystein
Ø
Størkersen
Deparment of Circulation and Medical Imaging, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Mail MTFS*3.1313, POBox 8905, N-7491, Trondheim, Norway.
May-Britt
MB
Tessem
Deparment of Circulation and Medical Imaging, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Mail MTFS*3.1313, POBox 8905, N-7491, Trondheim, Norway.|Department of Laboratory Medicine, Children's and Women's Health, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Trondheim, Norway.
Siver A
SA
Moestue
Department of Urology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.|Department of Cancer Research and Molecular Medicine, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Trondheim, Norway.
Helena
H
Bertilsson
Deparment of Circulation and Medical Imaging, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Mail MTFS*3.1313, POBox 8905, N-7491, Trondheim, Norway.|St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
Tone F
TF
Bathen
D000368:Aged; D002264:Carboxylic Acids / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D003503:Cyclobutanes / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity
D002264:Carboxylic Acids; D003503:Cyclobutanes; D019275:Radiopharmaceuticals; C117460:fluciclovine F-18
Dynamic PET; PET/MRI; Prostate Cancer; [18F]FACBC; [18F]Fluciclovine