Study of PSMA PET/CT Imaging to Help Select Men With Low-Risk Prostate Cancer for Active Surveillance

Official title

Prospective Evaluation of Istanbul PSMA PET/CT Criteria for Selecting Candidates for Active Surveillance in Low-Risk Prostate Cancer

Overview

This is a multicenter, prospective diagnostic accuracy study evaluating the Istanbul PSMA PET/CT Criteria (IPPC) for selecting patients with biopsy-confirmed low-risk prostate cancer (ISUP Grade 1) for active surveillance (AS). The study integrates delayed Ga-68 PSMA PET/CT imaging into the diagnostic pathway to refine patient stratification, minimize overtreatment and potentially reduce unnecessary biopsies and MRI, or exposing high-risk individuals to the danger of cancer progression if left untreated scans.

Detailed description

Prostate cancer is the most common malignancy in men and demonstrates heterogeneous clinical behavior. While many low-risk patients have indolent disease, a subset harbors clinically significant prostate cancer (csPCa) requiring early intervention. Active Surveillance (AS) is widely used to avoid overtreatment; however, current selection criteria-PSA, DRE, biopsy Gleason score, number of positive cores, PSA density, and mpMRI-lack sufficient predictive accuracy. Studies indicate that up to 30% of patients classified as low-risk by biopsy are found to have higher-grade disease at radical prostatectomy. The Istanbul PSMA PET/CT Criteria (IPPC) were developed by a multidisciplinary expert panel in Turkey to classify intraprostatic lesions on delayed (120-minute) Ga-68 PSMA PET/CT imaging into three risk categories:

* IPPC 1 No or homogeneous low uptake - safe for monitoring. * IPPC 2: Indeterminate uptake - AS with close follow-up. * IPPC 3: Focal, lentiform, high SUVmax ≥12 uptake in peripheral zone - definitive treatment recommended.

This study will evaluate the diagnostic performance of IPPC compared to standard mpMRI and biopsy findings, using radical prostatectomy pathology or long-term clinical follow-up as the reference standard.

Interventions

• Diagnostic test Ga-68 PSMA11 PET/CT
  delayed (120-minute) Ga-68 PSMA PET/CT and will be evaluated by using Istanbul PSMA PET/CT Criteria (IPPC)

Primary outcome measures

• 1. Diagnostic Accuracy of the Istanbul PSMA PET/CT Criteria (IPPC) for Detecting Clinically Significant Prostate Cancer (csPCa) [Time frame: Baseline imaging; confirmed at prostatectomy or through 2-year follow-up.]

Secondary outcome measures (1)

• Reduction in Repeat Biopsy Rate [Time frame: Assessed over 2 years.]

Eligibility criteria

Inclusion criteria

• mpMRI performed within 3 months prior to enrollment
• Systematic or MRI-targeted prostate biopsy performed
• Biopsy-confirmed ISUP Grade 1 low-risk PCa
• Prostate biopsy report specifying tumor localization and number of positive cores
• Meets AS criteria: ISUP 1, PSA ≤10 ng/mL, PSAd >0.15 ng/mL², clinical stage cT1c-T2a, ≤3 positive cores
• Life expectancy ≥10 years
• No prior PSMA PET imaging
• No evidence of extra-prostatic disease on mpMRI
• Signed informed consent for study procedures

Exclusion criteria

• High-risk or unfavorable intermediate-risk PCa, or adverse histologies (neuroendocrine, ductal adenocarcinoma, basal cell carcinoma, TP53 or BRCA1/2 mutations if available)
• Prior prostate cancer treatment or prostate surgery
• MRI evidence of extracapsular extension, seminal vesicle invasion, or nodal metastasis
• History of pelvic radiotherapy
• Life expectancy <10 years
• Severe renal impairment
• Inability to comply with follow-up schedule

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

Turkey (Türkiye) · 10 centers

• Yeditepe University — Istanbul
• Bilkent Şehir Hastanesi — Ankara
• Gazi Yaşargil Egitim ve Arastirma Hastanesi — Diyarbakır
• Gaziantep Üniversitesi Şahinbey Araştırma ve Uygulama hastanesi — Gaziantep
• Acibadem University Altunizade Hospital — Istanbul
• Acibadem University Maslak Hospital — Istanbul
• Haseki Eğitim ve Araştırma Hastanesi — Istanbul
• Istanbul University-Cerrahpaşa — Istanbul
• … and 2 more centers

Publications

• Akcay K, Beydagi G, Sahin OE, Akyel R, Akgun E, Ekmekcioglu O, Alan Selcuk N, Toklu T, Dogan Ekici AI, Kapran K, Kabasakal L. Improved Accuracy and Reliability of PRIMARY Scoring Using Delayed [68Ga] Ga-PSMA PET/CT Imaging. Mol Imaging Radionucl Ther. 2025 Feb 7;34(1):1-9. doi: 10.4274/mirt.galenos.2025.16023. PMID 39917984
• Emmett L, Papa N, Buteau J, Ho B, Liu V, Roberts M, Thompson J, Moon D, Sheehan-Dare G, Alghazo O, Agrawal S, Murphy D, Stricker P, Hope TA, Hofman MS. The PRIMARY Score: Using Intraprostatic 68Ga-PSMA PET/CT Patterns to Optimize Prostate Cancer Diagnosis. J Nucl Med. 2022 Nov;63(11):1644-1650. doi: 10.2967/jnumed.121.263448. Epub 2022 Mar 17. PMID 35301240
• Akcay K, Kibar A, Sahin OE, Demirbilek M, Beydagi G, Asa S, Aghazada F, Toklu T, Selcuk NA, Onal B, Kabasakal L. Prediction of clinically significant prostate cancer by [68 Ga]Ga-PSMA-11 PET/CT: a potential tool for selecting patients for active surveillance. Eur J Nucl Med Mol Imaging. 2024 Apr;51(5):1467-1475. doi: 10.1007/s00259-023-06556-y. Epub 2023 Dec 19. PMID 38112777
• Cornford P, van den Bergh RCN, Briers E, Van den Broeck T, Brunckhorst O, Darraugh J, Eberli D, De Meerleer G, De Santis M, Farolfi A, Gandaglia G, Gillessen S, Grivas N, Henry AM, Lardas M, van Leenders GJLH, Liew M, Linares Espinos E, Oldenburg J, van Oort IM, Oprea-Lager DE, Ploussard G, Roberts MJ, Rouviere O, Schoots IG, Schouten N, Smith EJ, Stranne J, Wiegel T, Willemse PM, Tilki D. EAU-EAN PMID 38614820

Identifiers

NCT: NCT07168616 · 2024-KAEK-21/1153

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗