RET-Targeted Molecular Imaging Probes in Prostate Cancer

NCT07886138 | Active Not Recruiting Early Phase 1 DMC

• 1 other identifier: 202601018
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this observational diagnostic imaging study is to evaluate the value of RET-targeted PET/CT molecular imaging in diagnosing neuroendocrine prostate cancer (NEPC) and in assessing disease activity, treatment response, and prognosis. The study population consists of men aged 45-80 years, including approximately 40 patients with suspected or confirmed NEPC (positive group) and approximately 10 patients with conventional prostatic adenocarcinoma (negative control group). The main questions it aims to answer are: Can RET-targeted PET/CT imaging accurately diagnose neuroendocrine prostate cancer, using pathology as the gold standard? Compared with PSMA PET/CT, multiparametric MRI (mpMRI), and serum markers, does RET-targeted PET/CT provide better diagnostic performance (sensitivity, specificity, positive and negative predictive values)? Is the level of RET tracer uptake in lesions associated with disease progression and prognosis, and can it be used for early assessment of treatment response? Researchers will compare RET-PET/CT imaging results against pathology (the primary reference standard), PSMA PET/CT, conventional contrast-enhanced MRI, and serum markers to determine the diagnostic advantage of RET-targeted imaging. Participants will: Sign a written informed consent form; Undergo whole-body PET/CT (and if needed, PET/MRI) imaging with RET- and PSMA-targeted tracers (approximately 0.15 mCi/kg injected intravenously; if a repeat scan is needed due to disease changes, it will be performed at least 1 week apart); Have blood pressure, pulse, respiration, and temperature measured before and after imaging, and liver/kidney function tests and routine blood and urine tests performed one day before and after imaging; Undergo multiparametric MRI (mpMRI); Be followed up, with any clinical symptoms or signs of discomfort during and up to two weeks after imaging recorded in detail.

Conditions

Prostate Cancer; Prostate Adenocarcinoma With Focal Neuroendocrine Differentiation

Outcome Measures

Primary Outcomes (1)

• Diagnostic accuracy of RET-targeted PET/CT for neuroendocrine prostate cancer (NEPC)

  The diagnostic performance of RET-targeted PET/CT for NEPC will be evaluated against pathology (the gold standard, based on biopsy or surgical specimen with neuroendocrine marker immunohistochemistry: SYP/CHGA/NSE). Diagnostic accuracy parameters, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), will be calculated.

  At the time of imaging, with pathology confirmation within approximately 1 month after imaging

Secondary Outcomes (4)

• Comparison of diagnostic performance between RET-PET/CT and PSMA PET/CT

  At the time of imaging

• Semi-quantitative tracer uptake (SUVmax and SUVmean) of lesions on RET-targeted PET/CT

  At the time of imaging

• Correlation between lesion SUVmax on RET-targeted PET/CT and disease progression

  Up to 5 years after enrollment

• Value of RET-targeted PET/CT for early assessment of treatment response

  During follow-up after treatment (repeat imaging at least 1 week apart when needed)

Study Arms (2)

RET-Targeted PET/CT Imaging in Neuroendocrine Prostate Cancer (NEPC) Patients

EXPERIMENTAL

Patients with suspected or confirmed neuroendocrine prostate cancer (NEPC) will undergo whole-body PET/CT imaging with a RET-targeted tracer and a PSMA-targeted tracer (approximately 0.15 mCi/kg injected intravenously). Imaging findings will be compared with pathology (the gold standard), serum neuroendocrine markers, and clinical follow-up to evaluate diagnostic performance, treatment response, and prognosis.

Diagnostic Test: RET-targeted PET/CT molecular imaging; Diagnostic Test: PSMA-targeted PET/CT imaging

Control: PET/CT Imaging in Conventional Prostatic Adenocarcinoma Patients

EXPERIMENTAL

Patients with conventional prostatic adenocarcinoma (control group) will undergo the same imaging procedures as the NEPC group: whole-body PET/CT (or PET/MRI) with a RET-targeted tracer and a PSMA-targeted tracer (approximately 0.15 mCi/kg intravenously), plus multiparametric MRI (mpMRI), to serve as the negative control for evaluating the specificity of RET-targeted imaging.

Diagnostic Test: RET-targeted PET/CT molecular imaging; Diagnostic Test: PSMA-targeted PET/CT imaging

Interventions

RET-targeted PET/CT molecular imaging DIAGNOSTIC_TEST

Participants receive an intravenous injection of a RET-targeted PET tracer (approximately 0.15 mCi/kg, nanomolar tracer dose, radiochemical purity \>95%) prepared and quality-controlled at the investigators' PET center. After resting in a dark room for 5-10 or 45-60 minutes and voiding, whole-body PET/CT (or PET/MRI for head and spine) imaging is performed with an emission scan time of 10-20 minutes. PET images are reconstructed by OSEM. Two experienced nuclear medicine physicians review the images; a lesion with tracer uptake higher than surrounding or contralateral normal tissue is considered positive, and SUVmax, SUVmean, and lesion size are measured by ROI analysis. If disease changes require a repeat scan, it is performed at least 1 week apart.

Control: PET/CT Imaging in Conventional Prostatic Adenocarcinoma Patients; RET-Targeted PET/CT Imaging in Neuroendocrine Prostate Cancer (NEPC) Patients

PSMA-targeted PET/CT imaging DIAGNOSTIC_TEST

Participants undergo whole-body PET/CT (or PET/MRI) imaging with a PSMA-targeted tracer (approximately 0.15 mCi/kg injected intravenously) using the same scanner, protocol, image reconstruction, and image analysis procedures as the RET-targeted imaging. PSMA imaging serves as the comparator to evaluate the diagnostic performance of RET-targeted imaging.

Control: PET/CT Imaging in Conventional Prostatic Adenocarcinoma Patients; RET-Targeted PET/CT Imaging in Neuroendocrine Prostate Cancer (NEPC) Patients

Eligibility Criteria

• Age: 45 Years - 80 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male patients aged 45-80 years.
• Diagnosed with conventional prostatic adenocarcinoma or neuroendocrine prostate cancer (NEPC) by clinical data, serum markers, and pathology (biopsy); patients with no other neuroendocrine tumors or related diseases and no history of acute infection or acute trauma.
• Patients with newly diagnosed disease will be enrolled before receiving specific treatment (ADT, chemotherapy, second-generation androgen receptor inhibitors, etc.) whenever possible; patients with recurrent disease will be enrolled as soon as possible.
• Able to cooperate in the observation of adverse events and efficacy.
• Patients with suspected NEPC based on positive serum neuroendocrine markers (SYP/CHGA/NSE), or confirmed NEPC by biopsy histopathology with positive neuroendocrine marker immunohistochemistry (SYP/CHGA/NSE).
• Capable of undergoing pathological examination to confirm the diagnosis; willing to provide informed consent and able to accept follow-up.
• The patient or his legally authorized representative signs the written informed consent form.

You may not qualify if:

• Patients without prostate cancer.
• Fever with body temperature above 38°C or clinically evident active infection that could affect the trial.
• Cardiac, pulmonary, hepatic, or renal function assessed as unsuitable for the examination (e.g., organic heart disease or arrhythmia; abnormal pulmonary function such as FVC, FEV1, FEV1/FVC, DLCO, or DLCO/VA outside the normal range with ventilatory disorders; abnormal liver function with AST, ALT, or ALP more than 1 times the upper limit of the reference range; total/direct bilirubin above normal or total protein, albumin, and globulin below normal; abnormal renal function such as hematuria or proteinuria, or creatinine, urea, or uric acid above normal values).
• Uncontrolled hypertension (systolic blood pressure \>160 mmHg or diastolic blood pressure \>100 mmHg).
• Abnormal coagulation function (PET/CT involves venous injection; normal coagulation must be ensured).
• Significant cardiovascular abnormalities (e.g., myocardial infarction, superior vena cava syndrome, grade 2 or higher heart disease before enrollment, or heart disease that increases the risk of ventricular arrhythmia as judged by the investigator).
• History of arrhythmia (multifocal ventricular premature beats, bigeminy, trigeminy, or congenital long QT syndrome).
• Tachycardia or uncontrolled atrial fibrillation, symptomatic or requiring treatment (CTCAE grade 3), or asymptomatic sustained tachycardia.
• Presence of left bundle branch block.
• Third-degree atrioventricular block or symptomatic sick sinus syndrome.
• Patients who cannot complete the PET examination due to disease progression.
• Patients too ill to undergo further evaluation and treatment.

Sponsors & Collaborators

• Xiangya Hospital of Central South University: lead

Study Sites (1)

Xiangya Hospital of Central South University

Changsha, Hunan, 410008, China

Location

MeSH Terms

Conditions

Prostatic Neoplasms

Condition Hierarchy (Ancestors)

Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Prostatic Diseases; Male Urogenital Diseases

Study Design

• Study Type: interventional
• Phase: early phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 9, 2026
• First Posted: October 21, 2026
• Study Start: April 3, 2026
• Primary Completion (Estimated): April 3, 2027
• Study Completion (Estimated): April 3, 2027
• Last Updated: October 21, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)