Prospective head-to-head comparison of [68Ga]Ga-RM2 PET/CT and [68Ga]Ga-PSMA-617 PET/CT in newly diagnosed patients with intermediate-risk localized prostate cancer

Florian Perozziello, Grégoire Robert, Marie Meyer, Eva Jambon, Franck Bladou, Mokrane Yacoub, Frédéric Lamare, Delphine Vimont, Nicolas Balamoutoff, Elif Hindié, Clément Morgat
European Journal of Nuclear Medicine and Molecular Imaging. 2026-02-09; 53(7): 4386-4394
DOI: 10.1007/s00259-026-07780-y

1. Eur J Nucl Med Mol Imaging. 2026 Jun;53(7):4386-4394. doi:
10.1007/s00259-026-07780-y. Epub 2026 Feb 9.

Prospective head-to-head comparison of [(68)Ga]Ga-RM2 PET/CT and
[(68)Ga]Ga-PSMA-617 PET/CT in newly diagnosed patients with intermediate-risk
localized prostate cancer.

Perozziello F(1), Robert G(2), Meyer M(1), Jambon E(3), Bladou F(2), Yacoub
M(4), Lamare F(1)(5), Vimont D(5), Balamoutoff N(1), Hindié E(1)(5)(6), Morgat
C(7)(8).

Author information:
(1)Nuclear Medicine & Radiopharmacy Department, Bordeaux University Hospital,
Bordeaux, France.
(2)Department of Urology, Bordeaux University Hospital, Bordeaux, France.
(3)Department of Radiology, Bordeaux University Hospital, Bordeaux, France.
(4)Department of Pathology, Bordeaux University Hospital, Bordeaux, France.
(5)INCIA, University of Bordeaux, CNRS, EPHE, UMR 5287, Bordeaux, France.
(6)Institut Universitaire de France (IUF), Paris, France.
(7)Nuclear Medicine & Radiopharmacy Department, Bordeaux University Hospital,
Bordeaux, France. .
(8)INCIA, University of Bordeaux, CNRS, EPHE, UMR 5287, Bordeaux, France.
.

PURPOSE: Intermediate-risk (IR) prostatic adenocarcinoma is an heterogeneous
subgroup of prostate cancer with discrepant progression and prognosis. These
tumors can be subclassified based on the ISUP (International Society of Urology
Pathology) score into favorable (ISUP 2) and unfavorable (ISUP 3) IR prostate
cancer. Positron Emission Tomography / Computed Tomography (PET/CT) imaging
targeting PSMA (Prostate Specific Membrane Antigen) is recommended for the
assessment of high-risk prostate cancers. On the other hand, GRPR
(Gastrin-Releasing Peptide Receptor) is over-expressed in low-risk prostate
cancers (low ISUP score, low PSA and small tumor size). The aim of this study is
to evaluate the relevance of PSMA- and GRPR-targeted PET/CT imaging for primary
tumor stratification in newly diagnosed intermediate-risk patients. METHODS: 22
patients with biopsy-confirmed intermediate-risk prostate cancer with no prior
treatment and candidates for radical prostatectomy were imaged with
[68Ga]Ga-PSMA-617 (a radiolabeled PSMA-inhibitor) and [68Ga]Ga-RM2 (a
radiolabeled GRPR antagonist). Histology served as reference. Magnetic Resonance
Imaging (MRI) was available in 18 patients. RESULTS: [68Ga]Ga-RM2 SUVmax was
significantly higher than [68Ga]Ga-PSMA-617 SUVmax in ISUP ≤ 2 lesions (p =
0.027). [68Ga]Ga-PSMA-617 SUVmax was significantly higher in ISUP ≥ 3 lesions
than ISUP ≤ 2 lesions (p = 0.001) CONCLUSION: These results suggest that the
combined use of PSMA imaging and GRPR imaging is able to discriminate ISUP 2
from ISUP 3 prostate cancer and thus provides valuable information for treatment
decision making. TRIAL REGISTRATION NUMBER: NCT03606837 (prospectively
registered on 11/07/2019).

DOI: 10.1007/s00259-026-07780-y
PMID: 41656418 [Indexed for MEDLINE]

Conflict of interest statement: Declarations. Ethics approval: This study was
performed in line with the principles of the Declaration of Helsinki. Approval
was granted by the Ethics Committee of Ide France 8. Consent to participate:
Informed consent was obtained from all individual participants included in the
study. Consent to publish: The authors affirm that human research participants
provided informed consent for publication of the images in Figs. 1 and 2.
Competing interests: CM reports consulting activities for IRE Elit and research
supports from IRE Elit and Life Molecular Imaging (LMI) outside this research
support.