Abstract
BackgroundProstate-specific membrane antigen (PSMA) ligand PET/CT has already provided promising results in prostate cancer (PC) imaging, yet simple and reproductible reporting criteria are still lacking. This study aimed at retrospectively evaluating interobserver agreement of [68Ga]Ga-PSMA-11 PET/CT images interpretation according to PC molecular imaging standardized evaluation (PROMISE) criteria and reproducibility of PSMA reporting and data systems (RADS).MethodsForty-three patients with newly diagnosed, histologically proven intermediate- or high-risk PC, eligible for radical prostatectomy and who underwent [68Ga]Ga-PSMA-11 PET/CT before surgery were retrospectively included. Three nuclear medicine physicians (2 experienced and 1 resident) independently reviewed PET/CT images. Interpretation of [68Ga]Ga-PSMA-11 PET/CT images was based on PROMISE criteria including miTNM staging and lesions miPSMA expression score visual estimation and PSMA-RADS version 1.0 for a given scan. Readers’ agreement was measured using Krippendorff’s coefficientsResultsAgreement between observers was almost perfect (coefficient ≥ 0.81) for miM; it was substantial (coefficient ≥ 0.61) for the following criteria: miT, miN, PSMA-RADS, and miPSMA expression score of primary PC lesion and metastases. However, agreement was moderate (coefficient = 0.41–0.60) for miPSMA score of positive lymph nodes and for detection of PC primary lesion.ConclusionVisual interpretation of [68Ga]Ga-PSMA-11 PET/CT images in patients with newly diagnosed PC in a clinical setting leads to at least substantial agreement for PROMISE criteria and PSMA-RADS classification except for PC primary lesion detection and for miPSMA expression scoring of positive lymph nodes that might have been hampered by the interindividual variability of reference organs PSMA expression.
Highlights
Prostate-specific membrane antigen (PSMA) ligand positron emission tomography (PET) combined with computed tomography (CT) radically improved prostate cancer (PC) imaging thanks to its superior sensitivity compared to CT and bone scintigraphy [1]
The inter-reader agreement of the PC molecular imaging standardized evaluation (PROMISE) proposed by Eiber et al was substantial for interpretation of [68Ga]Ga-PSMA-11 PET/CT in a population of patients with biochemically recurrent PC [7, 10], though authors recently showed that PROMISE criteria agreement was significantly lower for [18F]fluciclovine than for [68Ga]Ga-PSMA-11 [11]
The number of focal lesions in the prostate gland was concordant in 26/43 patients (60%; n = 1 focal prostate lesion in 20/ 43 patients and n = 2 focal lesions in 6/43 patients), and interobserver agreement was moderate (K’s alpha 0.50; 95% confidence interval (95% CI) 0.34–0.66). 43/43 (49%) patients who had 1 focal uptake only, observers were discordant for 1/43 (2%) patient only, for which one observer did not describe any significant focal uptake; whereas multiple focal prostate uptake was described by at least one observer in 22/43 (51%) patients and observers were discordant regarding the number of lesions for 16/22 (72%) patients
Summary
Prostate-specific membrane antigen (PSMA) ligand positron emission tomography (PET) combined with computed tomography (CT) radically improved prostate cancer (PC) imaging thanks to its superior sensitivity compared to CT and bone scintigraphy [1]. Derwael et al EJNMMI Research (2020) 10:15 criteria have been first proposed by Fanti et al in 2017 and assessed using the Delphi approach of consensus between experts of seven international PET facilities to detect recurrent PC lesions [5] As it is the case in other areas of imaging that adopt reporting and data systems (RADS) to standardize the interpretation and reporting of findings from a specific imaging modality, Rowe et al proposed a PSMA-RADS version 1.0 [6]. Toriihara et al tested the three standardised interpretation criteria proposed by Fanti et al, Rowe et al and Eiber et al in a population of patients who underwent either [68Ga]GaPSMA-11 PET/MR for PC primary staging or [68Ga]GaPSMA-11 PET/CT for recurrent PC [12] They revealed at least substantial agreement of the three classification systems, except in the evaluation of distant metastases based on PSMA-RADS [12]. This study aimed at retrospectively evaluating interobserver agreement of [68Ga]Ga-PSMA-11 PET/CT images interpretation according to PC molecular imaging standardized evaluation (PROMISE) criteria and reproducibility of PSMA reporting and data systems (RADS)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
