Diagnostic Value of CXCR4-targeted PET/CT in ACTH-dependent and Independent Cushing's Syndrome

Chinese Academy of Medical Sciences & Peking Union Medical College

Status and phase: Enrolling; Phase 2; Phase 1

Conditions: Cushing s Syndrome

Treatments: Drug: 68Ga-Pentixafor

Study type: Interventional

Funder types: Other

Identifiers

NCT07350707

PUMCH-68Ga-CXCR4-Cushing

Details and patient eligibility

About

In previous clinical practice, 68Ga-Pentixafor PET/CT has demonstrated promising diagnostic utility in various neuroendocrine tumors by targeting CXCR4, a chemokine receptor overexpressed in several ACTH-secreting neoplasms. Building on this, and leveraging the Nuclear Medicine expertise at Peking Union Medical College Hospital, we aim to conduct a prospective observational study investigating the role of CXCR4-targeted PET/CT imaging in patients with confirmed or suspected Cushing's syndrome. This study will focus on evaluating the capability of ^68Ga-Pentixafor PET/CT to assist in the differential diagnosis of ACTH-dependent and ACTH-independent subtypes, as well as in the localization of primary lesions in challenging cases. Imaging performance will be assessed in comparison with conventional modalities and/or 68Ga-DOTATATE PET/CT when available.

Enrollment: 160 estimated patients

Sex: All

Ages: 10 to 80 years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Diagnostic

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

---

160 participants in 1 patient group

68Ga-Pentixafor PET/CT

Experimental group

Description:

All enrolled participants will undergo \^68Ga-Pentixafor PET/CT to evaluate CXCR4 expression patterns and assist in the differential diagnosis of ACTH-dependent and ACTH-independent subtypes. In cases where ectopic ACTH syndrome (EAS) is clinically suspected-such as in patients with inconclusive pituitary imaging or discordant biochemical profiles-an additional \^68Ga-DOTATATE PET/CT scan will be performed as part of the diagnostic workup. This allows for a head-to-head comparison between CXCR4-targeted and somatostatin receptor (SSTR)-targeted imaging modalities in the localization of ACTH-secreting tumors.

Treatment:

Drug: 68Ga-Pentixafor