Open AccessUtility of 18F-Fluciclovine PET/MRI for Staging Newly Diagnosed High-Risk Prostate Cancer and Evaluating Response to Initial Androgen Deprivation Therapy: A Prospective Single-Arm Pilot Study
Author(s) -
Samuel J. Galgano,
Andrew M. McDonald,
Soroush RaisBahrami,
Kristin K. Porter,
Gagandeep Choudhary,
Constantine M. Burgan,
Pradeep Bhambhvani,
Jeffrey Nix,
Desiree E. Morgan,
Yufeng Li,
John V. Thomas,
Jonathan McConathy
Publication year - 2021
Publication title -
american journal of roentgenology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 196
eISSN - 1546-3141
pISSN - 0361-803X
DOI - 10.2214/ajr.20.24509
Subject(s) - medicine , prostate cancer , androgen deprivation therapy , prostate , prospective cohort study , radiology , biochemical recurrence , stage (stratigraphy) , magnetic resonance imaging , lymph node , biopsy , positron emission tomography , radiation therapy , nuclear medicine , cancer , prostatectomy , paleontology , biology
BACKGROUND. Despite advances in prostate cancer treatment, rates of biochemical recurrence remain high, relating to lack of detection of small-volume metastatic disease using conventional imaging for initial staging. OBJECTIVE. The purpose of this study was to assess the potential use of 18 F-fluciclovine PET/MRI for initial staging of high-risk prostate cancer and evaluating response to androgen deprivation therapy (ADT). METHODS. This prospective clinical trial enrolled 14 men with newly diagnosed high-risk prostate cancer and negative or equivocal conventional staging imaging for metastatic disease between January 2018 and February 2019. All patients underwent pretreatment 18 F-fluciclovine PET/MRI including multiparametric prostate MRI; 12 underwent 18 F-fluciclovine PET/MRI after surgery or between ADT and radiotherapy. Confidence in identification of the primary intraprostatic lesion and nodal metastases was independently rated on a 0-3 Likert scale by three readers with nuclear medicine experience for 18 F-fluciclovine PET/MRI and three readers with abdominal imaging experience for MRI alone. Findings scored as 2 or 3 by at least two readers of a given modality were considered positive. A single reader measured SUV mean , SUV max , and volume of the MRI-defined intraprostatic lesion and SUV max of suspicious lymph nodes on PET before and after initiation of ADT. Changes in SUV were analyzed using nonparametric Wilcox-on signed-rank tests. RESULTS. The biopsy-proven lesion in the prostate gland was accurately identified in all 14 patients on both MRI and 18 F-fluciclovine PET/MRI. Suspected nodal metastases were detected in three patients on MRI and seven patients on 18 F-fluciclovine PET/MRI. After ADT, all patients showed decreased activity within the intraprostatic lesion and/or all suspicious lymph nodes. The primary lesion SUV mean was 4.5 ± 1.1 (range, 2.7-6.5) before treatment and 2.4 ± 1.1 (range, 0.0-3.6) after initiation of ADT ( p = .008). For suspicious lymph nodes, the pretreatment SUV max was 5.5 ± 3.7 (range, 2.8-12.7) and the post-treatment SUV max was 2.8 ± 1.4 (range, 1.4-5.5) ( p = .03). CONCLUSION. 18 F-labeled fluciclovine PET/MRI shows potential utility in initial staging of high-risk prostate cancer and in evaluating response to ADT. CLINICAL IMPACT. Given the FDA approval and widespread availability of 18 F-fluciclovine, the findings could have an impact in the immediate future in guiding initial management of patients with prostate cancer. TRIAL REGISTRATION. ClinicalTrials.gov NCT03264456.