Prospective Study of the Radiolabeled GRPR Antagonist BAY86-7548 for Positron Emission Tomography/Computed Tomography Imaging of Newly Diagnosed Prostate Cancer

Touijer, Karim; Michaud, Laure; Alvarez, Herbert A. Vargas; Gopalan, Anuradha; Kossatz, Susanne; Gönen, Mithat; Beattie, Bradley J.; Sandler, Israel; Lyaschenko, Serge; Eastham, James A.; Scardino, Peter T.; Hricak, Hedvig; Weber, Wolfgang

doi:10.1016/j.euo.2018.08.011

Cited by 53 publications

(61 citation statements)

References 27 publications

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“…They concluded that both tracers show a "different localization of lesions but similar semiquantitative measurements". A comparable conclusion was drawn by Touijer et al who compared RM2-PET of PCa with multiparametric magnetic resonance imaging, histopathology, and immunohistochemistry [38]. They state that "GRPR expression appears to be independent from PSMA expression suggesting that GRPR-and PSMA-targeted PET imaging may be complementary".…”

Section: Discussionsupporting

confidence: 53%

“…next to the bowel [35]. Recently, several studies showed promising results in further comparing RM2-PET and PSMA-PET in patients with biochemical recurrence of prostate cancer [36], in patients with newly diagnosed intermediate-or high-risk prostate cancer [37] and in comparing RM2-PET of PCa with multiparametric magnetic resonance imaging, histopathology, and immunohistochemistry [38]. Schollhammer et al even compared [Ga68]Ga-PSMA-617-PET/CT…”

Section: Introductionmentioning

confidence: 99%

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Voxel-based comparison of [68Ga]Ga-RM2-PET/CT and [68Ga]Ga-PSMA-11-PET/CT with histopathology for diagnosis of primary prostate cancer

et al. 2020

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Background: Focal therapies or focally escalated therapies of primary prostate cancer are becoming more and more important. This increases the need to identify the exact extension of the intraprostatic tumor and possible dominant intraprostatic lesions by imaging techniques. While the prostate-specific membrane antigen (PSMA) is already a well-established target for imaging of prostate cancer cells, the gastrin-releasing peptide receptor (GRPR) seems to provide interesting additional information. Histopathology was used to examine the extent to which the single and combined image information of PET scans targeting GRPR and PSMA might lead to better tumor delineation. Methods: Eight patients with histologically proven primary prostate cancer underwent two positron emission tomography with computer tomography scans, [ 68 Ga]Ga-RM2-PET/CT (RM2-PET) and [ 68 Ga]Ga-PSMA-11-PET/CT (PSMA-PET), prior to radical prostatectomy. RM2-PET data were correlated voxel-wise to a voxel-based model of the histopathologic tumor volume information. The results were compared to, correlated to, and combined with the correlation of PSMA-PET data analyzed analogously. Results: In 4/8 patients, RM2-PET showed a higher signal in histologically proven tumor regions compared to PSMA. There were also tumor regions where PSMA-PET showed a higher signal than GRPR in 4/8 patients. A voxelwise correlation of RM2-PET against histopathology yielded similar results compared to the correlation of PSMA-PET against histopathology, while PSMA-PET is the slightly better performing imaging technique. The combined information of both tracers yielded the best overall result, although this effect was not statistically significant compared to RM2-PET alone. Conclusions: Qualitative and quantitative findings in this preliminary study with 8 patients indicate that RM2-PET and PSMA-PET partially show not only the same, but also distinct regions of prostate cancer. Patients with pPCa might profit from information given by tracers targeting GRPR and PSMA simultaneously, in terms of a better delineation of the gross tumor volume.

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Section: Discussionsupporting

confidence: 53%

Section: Introductionmentioning

confidence: 99%

Voxel-based comparison of [68Ga]Ga-RM2-PET/CT and [68Ga]Ga-PSMA-11-PET/CT with histopathology for diagnosis of primary prostate cancer

et al. 2020

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“…The performances of 68 Ga-RM2 PET/CT imaging did not significantly differ compared to mpMRI in terms of sensitivity, specificity, and accuracy. Moreover, 68 Ga-RM2 binding did not correlate with Gleason score [24]. To date, no intra-patient comparison of PSMA and GRP-R targeting at initial staging was reported.…”

Section: Discussionmentioning

confidence: 99%

“…However, data from GRP-R immunohistochemistry and our results did not necessarily translate into parallel findings at patient imaging in pilot studies. For instance, the only two GRP-R imaging study, performed at the initial staging of prostate cancer, did not show any correlation (positive or negative) between SUV max on PET/CT and Gleason scores [10, 24]. However, only 1/16 prostate cancers in the study by Touijer et al and 2/17 in the study by Zhang et al were Gleason 6 [10, 24].…”

Section: Discussionmentioning

confidence: 99%

Comparison of the radiolabeled PSMA-inhibitor 111In-PSMA-617 and the radiolabeled GRP-R antagonist 111In-RM2 in primary prostate cancer samples

et al. 2019

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Purpose Prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRP-R) are expressed in prostate cancer and can be targeted with radiolabeled inhibitors and antagonists. Their performances for the initial characterization of prostatic tumors have been barely evaluated but never compared. We aimed to gather comparative preclinical data of the role of PSMA and GRP-R targeting in prostate cancer. Procedures We retrospectively studied 20 frozen prostatectomy samples with various metastatic risks of the D’Amico classification. Tissue samples were investigated by tissular microimaging using the radiolabeled PSMA inhibitor 111 In-PSMA-617 and the radiolabeled GRP-R antagonist 111 In-RM2. Bindings of the two radiopharmaceuticals were compared to histology and clinico-biological data (Gleason score, PSA values, metastatic risks). Results Binding of 111 In-PSMA-617 was high whatever the metastatic risk ( p = 0.665), Gleason score ( p = 0.555), or PSA value ( p = 0.404) while 111 In-RM2 exhibited a significantly higher binding in the low metastatic risk group ( p = 0.046), in the low PSA value group ( p = 0.001), and in samples with Gleason 6 score ( p = 0.006). Conclusion PSMA and GRP-R based imaging might have complementary performances for the initial characterization of prostatic tumors. Prospective clinical studies comparing the two tracers in this setting are needed.

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“…Because of the frequent overexpression of GRPR in prostate cancer, several bombesin radiopharmaceuticals have been tested in humans for PCa disease detection, including [ 68 Ga]RM2, [ 68 Ga]BAY86-7548, and [ 64 Cu]-CB-TE2A-AR06, among others. Studies reveal high-contrast detection of disseminated and primary disease (83)(84)(85)(86). While GRPR expression may not be as ubiquitous on prostate cancer cells as PSMA, there is no background target expression in the kidneys or salivary glands.…”

Section: Grpr Bombesinmentioning

confidence: 99%

Prostate Cancer Theranostics - An Overview

et al. 2020

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Metastatic prostate cancer is incurable, and novel methods to detect the disease earlier and to direct definitive treatment are needed. Molecularly specific tools to localize diagnostic and cytotoxic radionuclide payloads to cancer cells and the surrounding microenvironment are recognized as a critical component of new approaches to combat this disease. The implementation of theranostic approaches to characterize and personalize patient management is beginning to be realized for prostate cancer patients. This review article summarized clinically translated approaches to detect, characterize, and treat disease in this rapidly expanding field.

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Prospective Study of the Radiolabeled GRPR Antagonist BAY86-7548 for Positron Emission Tomography/Computed Tomography Imaging of Newly Diagnosed Prostate Cancer

Cited by 53 publications

References 27 publications

Voxel-based comparison of [68Ga]Ga-RM2-PET/CT and [68Ga]Ga-PSMA-11-PET/CT with histopathology for diagnosis of primary prostate cancer

Voxel-based comparison of [68Ga]Ga-RM2-PET/CT and [68Ga]Ga-PSMA-11-PET/CT with histopathology for diagnosis of primary prostate cancer

Comparison of the radiolabeled PSMA-inhibitor 111In-PSMA-617 and the radiolabeled GRP-R antagonist 111In-RM2 in primary prostate cancer samples

Prostate Cancer Theranostics - An Overview

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