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

Istanbul University - Cerrahpasa

Status: Enrolling

Conditions: Clinically Significant Prostate Cancer; Low Risk Prostate Cancer

Treatments: Diagnostic Test: Ga-68 PSMA11 PET/CT

Study type: Observational

Funder types: Other

Identifiers

NCT07168616

2024-KAEK-21/1153

Details and patient eligibility

About

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.

Full 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.

Enrollment: 201 estimated patients

Sex: Male

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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