18F-FAPI PET in Cancers of Unknown Primary Site

January 20, 2026 updated by: First Affiliated Hospital of Zhejiang University

Prospective Clinical Study and Exploration of 18F-FAPI PET/CT Imaging in Cancers of Unknown Primary Site

This study aims to evaluate the diagnostic efficacy, therapeutic assessment, prognostic analysis, and impact on clinical treatment decisions of 18F-FAPI PET/CT in patients with cancer of unknown primary.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Primary endpoint: Diagnostic efficacy of 18F-FAPI PET/CT in patients with undetermined primary tumor (sensitivity, specificity, accuracy).

secondary end points:

  • The diagnostic performance of 18F-FAPI PET/CT compared with CT, MR and 18F-FDG PET in the clinical application of cancer with unknown primary site was compared.

    ④Assess the heterogeneity of sensitivity and specificity of 18F-FAPI PET/CT for different system sites (neck/thorax/abdomen).

  • Study on efficacy evaluation and prognostic prediction of 18F-FAPI PET/CT in patients with primary tumors of unknown origin.

Study Type

Observational

Enrollment (Estimated)

120

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • China
    • Zhejiang
      • Hangzhou, Zhejiang, China, 310003
        • The First Affiliated Hospital, Zhejiang University School of Medicine
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

120

Description

Inclusion Criteria:

  1. Patients with clinical or imaging suspicion of cancer of unknown primary origin.
  2. Patients with 18F FAPI PET scans.

Exclusion Criteria:

  1. Concurrent presence of other active malignant tumors or a history of other malignant tumors within the past 5 years;
  2. Severe uncontrollable diseases or active infections;
  3. Ineligible participants for project informed consent.
  4. Pregnant and lactating women.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
FAPI-cups
FAPI PET scan in patients with CUPs
Diagnostic test: 18F-FAPI PET
18F-FAPI-04 PET/CT

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Diagnostic efficacy
Time Frame: through study completion, an average of 1.5 year
Sensitivity, specificity, positive and negative predictive value of 18F-FAPI PET/CT Imaging in cancers of unknown primary site
through study completion, an average of 1.5 year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Standard uptake value （SUV）of tumor
Time Frame: through study completion, 3-4 years
This measure evaluates the association between baseline 18F-FAPI PET parameters (e.g., SUVmax, SUVmean).
through study completion, 3-4 years
Metabolic tumor volume (c) and total lesion glycolysis (TLG) of tumor
Time Frame: through study completion, 3-4 years
This measure evaluates the association between baseline 18F-FAPI PET parameters (MTV in cm3, TLG in cm3*SUV）
through study completion, 3-4 years
Prognostic Value of Baseline 18F-FAPI PET for Progression-Free Survival (PFS) in High-Risk Patients
Time Frame: through study completion, 3-4 years
Prognostic Value of Baseline 18F-FAPI PET for Progression-Free Survival (PFS) in High-Risk Patients
through study completion, 3-4 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

First Affiliated Hospital of Zhejiang University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

February 1, 2026

Primary Completion (Estimated)

December 31, 2027

Study Completion (Estimated)

December 31, 2028

Study Registration Dates

First Submitted

December 25, 2025

First Submitted That Met QC Criteria

January 20, 2026

First Posted (Actual)

January 28, 2026

Study Record Updates

Last Update Posted (Actual)

January 28, 2026

Last Update Submitted That Met QC Criteria

January 20, 2026

Last Verified

December 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • FirstZhejiangU-FAPI-CUPs

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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