CXCR4-targeted PET/CT to find the source of Cushing's syndrome

CXCR4-Targeted PET Imaging for the Differential Diagnosis of ACTH-Dependent and ACTH-Independent Cushing's Syndrome: A Prospective Observational Study

This trial will try 68Ga‑Pentixafor (CXCR4) PET/CT scans to help tell apart ACTH-dependent and ACTH-independent Cushing's syndrome and to locate the tumors causing the condition in people with suspected or confirmed Cushing's.

Quick facts

• Phase: PHASE1; PHASE2
• Study type: Interventional
• Enrollment: 160 (estimated)
• Ages: 10 Years to 80 Years
• Sex: All
• Sponsor: Peking Union Medical College Hospital (other)
• Locations: 1 site (Beijing, Beijing Municipality)
• Trial ID: NCT07350707 on ClinicalTrials.gov

What this trial studies

This prospective observational effort at Peking Union Medical College Hospital will image patients with suspected or confirmed Cushing's syndrome using 68Ga‑Pentixafor (CXCR4) PET/CT. Imaging results will be compared with conventional modalities and with 68Ga‑DOTATATE PET/CT when available to aid differential diagnosis between ACTH-dependent and ACTH-independent forms and to localize primary lesions. Participants will undergo PET/CT imaging alongside routine biochemical and clinical evaluation, with image findings correlated to clinical reference standards. Performance metrics such as sensitivity, specificity, and localization rates will be reported.

Who should consider this trial

Good fit: Ideal candidates are people with suspected or confirmed Cushing's syndrome who can safely undergo PET/CT imaging and provide informed consent.

Not a fit: Patients who are pregnant or breastfeeding, allergic to gallium-based tracers, recently received therapeutic radiopharmaceuticals, or are clinically unstable are unlikely to benefit or may be excluded.

Why it matters

Potential benefit: If successful, this approach could improve the ability to locate disease-causing tumors and clarify the subtype of Cushing's, enabling more targeted treatment decisions.

How similar studies have performed: Previous reports have shown promising diagnostic use of 68Ga‑Pentixafor PET/CT in various neuroendocrine and some ACTH-secreting tumors, but its specific role in Cushing's differential diagnosis is still emerging.

Eligibility criteria

Inclusion Criteria:

* Clinical suspicion or confirmed diagnosis of Cushing's syndrome, based on clinical features (e.g., central obesity, moon face, muscle weakness) and/or abnormal cortisol-related biochemical tests.
* Able and willing to undergo PET/CT imaging with both 68Ga-Pentixafor and, when applicable, 68Ga-DOTATATE.
* Willing to provide informed consent for participation in the study.

Exclusion Criteria:

* Prior administration of therapeutic or investigational radiopharmaceuticals within 5 physical half-lives before study imaging.

Pregnancy or breastfeeding.

* History of allergic reaction to gallium-based tracers or related compounds.
* Clinically unstable condition or severe organ dysfunction that, in the investigator's opinion, would interfere with PET/CT imaging or study participation.
* Inability to complete both 68Ga-Pentixafor and, when applicable, 68Ga-DOTATATE PET/CT imaging due to clinical or logistical reasons.

Where this trial is running

Beijing, Beijing Municipality

• Peking Union Medical College Hospital — Beijing, Beijing Municipality, China (RECRUITING)

Study contacts

• Study coordinator: Zhaohui Zhu, MD

Conditions: Cushing s Syndrome, pentixafor, CXCR4, PET/CT