Fever of Unknown OriginNCT07430475
Utility of 18F-FDG PET/CT for Suspected Infection in the Inpatient Setting: a Single Centre Retrospective Cohort Study
An observational study of Fever of Unknown Origin and Inflammation of Unknown Origin, run by University of Adelaide at 1 site in Australia.
Trial summary
Retrospective cohort study of inpatients at a South Australian tertiary hospital who underwent 18F FDG-PET/CT for investigation of undifferentiated fever or inflammatory syndrome. The aim is to investigate the utility of FDG-PET/CT in the investigation of suspected infection in hospitalised adults. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Fever of Unknown Origin, Inflammation of Unknown Origin, Fever
- What is being tested?
- 18F-FDG PET/CT
- How many people
- 266 participants
- Where
- 1 siteAustralia
- Study dates
- 4 Jan 2022to 29 Jan 2024
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Consecutive adults referred for FDG-PET/CT for evaluation of undifferentiated fever, inflammation or infection.
Who may be able to join
- Inpatient at the Royal Adelaide Hospital
- FDG-PET/CT between 1st January 2022 - 31st December 2023
- Imaging request query included: infect* AND/OR Fever of Unknown Origin OR FUO AND/OR Pyrexia of Unknown Origin OR PUO AND/OR inflammat*
Who cannot join
- - Outpatient PET/CT
- Comparison imaging for established diagnosed infection
- PET/CT intended for evaluation of malignancy
- Evaluation of presumed or confirmed infective endocarditis
- Age less than 18 years
Trial locations and contacts
1 site in 1 country.
About this study
Retrospective cohort study of inpatients at a South Australian tertiary hospital who underwent 18F FDG-PET/CT for investigation of undifferentiated fever or inflammatory syndrome. The aim is to investigate the utility of FDG-PET/CT in the investigation of suspected infection in hospitalised adults. To establish the rate at which FDG-PET/CT contributes to a diagnosis, and how this impacts clinical management and outcomes. From this, to develop further understanding of for which patients this imaging modality contributes meaningfully to outcomes.
Read the detailed description
A retrospective cohort study of consecutive adult inpatients undergoing 18F-FDG PET/CT for suspected infection or inflammation, excluding infective endocarditis and malignancy-directed scans. Pre-PET variables include inflammatory markers, microbiological results, prior imaging findings and infectious diseases (ID) consultation. PET/CT utility will be adjudicated as diagnostic and/or associated with a change in management using a structured consensus process. Associations between pre-PET factors and clinical utility will be explored using descriptive and logistic analyses.
- Being tested
- 18F-FDG PET/CT
- Keywords
- FDG-PET/CT, PET, fever of unknown origin
- Medical subject headings
- Fever of Unknown Origin, Fever, Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
18F-FDG PET/CTDiagnostic test
Nuclear medicine imaging as a diagnostic tool with implication for change in clinical management
| Study group | Role | What they receive |
|---|---|---|
| Infectious diseases consultation | Not described Receives: Diagnostic Test: 18F-FDG PET/CT | |
| No infectious diseases consultation | Not described Receives: Diagnostic Test: 18F-FDG PET/CT | |
| Significant pre-PET imaging finding | Not described Receives: Diagnostic Test: 18F-FDG PET/CT | |
| No significant pre-PET imaging finding | Not described Receives: Diagnostic Test: 18F-FDG PET/CT | |
| High blood WCC prior to PET | Not described Receives: Diagnostic Test: 18F-FDG PET/CT | |
| Low WCC prior to PET | Not described Receives: Diagnostic Test: 18F-FDG PET/CT | |
| High CRP prior to PET | Not described Receives: Diagnostic Test: 18F-FDG PET/CT | |
| Low CRP prior to PET | Not described Receives: Diagnostic Test: 18F-FDG PET/CT |
What is being measured
The primary outcome is the main question the study is designed to answer.
Diagnostic yield
- Did PET contribute to diagnostic yield?:
- 1 = Yes: PET led to a finding either definitive e.g. confirmed by gold standard (microbiology, histopathology, intraoperative findings etc) or contributory, which guided diagnosis or management even without gold standard confirmation. Examples of contributory: PET showing vascular graft uptake, not explanted due to risk but presumptively treated Vertebral discitis suggested by PET, biopsied without culture, but presumptively treated and clinically improved PET negative - antibiotics ceased, patient remained well
- 0 = No: PET provided no new information, was misleading (i.e. PET result contradicted by later results), or no action was taken based on PET
Measured: 30 days
Secondary outcomes (3)
Clinical change in management
- Clinical change in management: was clinical care altered compared to the documented plan prior to PET? 0 = no, 1 = yes
- Yes: antimicrobial therapy, procedures/interventions (PET-guided site biopsy, or surgery/drainage), diagnostics e.g. further focussed imaging, or disposition e.g. palliative care transition
- No: there was no change to the management plan, or the plan was already determined by other data
Examples:
- PET confirmed a suspected diagnosis but the treatment plan was unchanged
- PET provided supporting evidence but no explicit management adjustment was documented
- PET was negative and no further management steps were taken because there was a pre-existing plan
Measured: 30 days
Change in antimicrobial management
•Change in antimicrobial duration/spectrum/therapeutic procedure: this change occurred as a result of PET
Measured: 30 days
Final diagnosis
- Final diagnosis: infection = 1, non-infectious = 2, malignancy = 3, unresolved = 4
Measured: 30 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Feb 2026
- Study start4 Jan 2022
- Primary completion29 Jan 2024
- Study completion29 Jan 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Fever of Unknown OriginStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 266 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Adelaide
- Sponsor type
- University, hospital or other
- Collaborators
- Central Adelaide Local Health Network Incorporated
- Responsible party
- Principal investigator, James Kimber, University of Adelaide
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07430475
- Sponsor's protocol ID
- 20340
- Status last verified
- Feb 2026
- First submitted
- 18 Feb 2026
- Last updated
- 24 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 24 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Utility of 18F-FDG PET/CT for Suspected Infection in the Inpatient Setting: a Single Centre Retrospective Cohort Study
- ClinicalTrials.gov ID
- NCT07430475
- Acronym / sponsor ID
- 20340
- Keywords
- FDG-PET/CT, PET, fever of unknown origin
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 266 participants (actual)
- Lead sponsor
- University of AdelaideUniversity, hospital or other
- Collaborators
- Central Adelaide Local Health Network Incorporated
- Study start
- 4 Jan 2022 (actual)
- Primary completion
- 29 Jan 2024 (actual)
- Study completion
- 29 Jan 2024 (actual)
- First posted
- 24 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Retrospective cohort study of inpatients at a South Australian tertiary hospital who underwent 18F FDG-PET/CT for investigation of undifferentiated fever or inflammatory syndrome. The aim is to investigate the utility of FDG-PET/CT in the investigation of suspected infection in hospitalised adults. To establish the rate at which FDG-PET/CT contributes to a diagnosis, and how this impacts clinical management and outcomes. From this, to develop further understanding of for which patients this imaging modality contributes meaningfully to outcomes.
Detailed description
A retrospective cohort study of consecutive adult inpatients undergoing 18F-FDG PET/CT for suspected infection or inflammation, excluding infective endocarditis and malignancy-directed scans. Pre-PET variables include inflammatory markers, microbiological results, prior imaging findings and infectious diseases (ID) consultation. PET/CT utility will be adjudicated as diagnostic and/or associated with a change in management using a structured consensus process. Associations between pre-PET factors and clinical utility will be explored using descriptive and logistic analyses.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 8
| Arm | Type | Receives |
|---|---|---|
| Infectious diseases consultation | – | Diagnostic Test: 18F-FDG PET/CT |
| No infectious diseases consultation | – | Diagnostic Test: 18F-FDG PET/CT |
| Significant pre-PET imaging finding | – | Diagnostic Test: 18F-FDG PET/CT |
| No significant pre-PET imaging finding | – | Diagnostic Test: 18F-FDG PET/CT |
| High blood WCC prior to PET | – | Diagnostic Test: 18F-FDG PET/CT |
| Low WCC prior to PET | – | Diagnostic Test: 18F-FDG PET/CT |
| High CRP prior to PET | – | Diagnostic Test: 18F-FDG PET/CT |
| Low CRP prior to PET | – | Diagnostic Test: 18F-FDG PET/CT |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Consecutive adults referred for FDG-PET/CT for evaluation of undifferentiated fever, inflammation or infection.
Key inclusion criteria (3 listed)
- Inpatient at the Royal Adelaide Hospital
- FDG-PET/CT between 1st January 2022 - 31st December 2023
- Imaging request query included: infect* AND/OR Fever of Unknown Origin OR FUO AND/OR Pyrexia of Unknown Origin OR PUO AND/OR inflammat*
Key exclusion criteria (5 listed)
- - Outpatient PET/CT
- Comparison imaging for established diagnosed infection
- PET/CT intended for evaluation of malignancy
- Evaluation of presumed or confirmed infective endocarditis
- Age less than 18 years
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 18F-FDG PET/CTNuclear medicine imaging as a diagnostic tool with implication for change in clinical management | Diagnostic test | High CRP prior to PET, High blood WCC prior to PET, Infectious diseases consultation, Low CRP prior to PET, Low WCC prior to PET, No infectious diseases consultation, No significant pre-PET imaging finding, Significant pre-PET imaging finding |
Primary outcome
Diagnostic yield
Time frame: 30 days
• Did PET contribute to diagnostic yield?: * 1 = Yes: PET led to a finding either definitive e.g. confirmed by gold standard (microbiology, histopathology, intraoperative findings etc) or contributory, which guided diagnosis or management even without gold standard confirmation. Examples of contributory: PET showing vascular graft uptake, not explanted due to risk but presumptively treated Vertebral discitis suggested by PET, biopsied without culture, but presumptively treated and clinically improved PET negative - antibiotics ceased, patient remained well * 0 = No: PET provided no new information, was misleading (i.e. PET result contradicted by later results), or no action was taken based on PET
3 secondary outcomes
Clinical change in management
Time frame: 30 days
Change in antimicrobial management
Time frame: 30 days
Final diagnosis
Time frame: 30 days
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Feb 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Fever of Unknown Origin and Inflammation of Unknown Origin, run by University of Adelaide at 1 site in Australia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 24 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Australia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Diagnostic yield (time frame: 30 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Feb 2026.