Comparison of 3 Diagnostic Strategies of PE: Planar V/Q Scan, CTPA, and V/Q SPECT. (SPECTACULAR)

February 3, 2025 updated by: University Hospital, Brest

Comparison of 3 Diagnostic Strategies of Pulmonary Embolism : Planar Ventilation-perfusion Scintigraphy (Planar V/Q Scan), Computed Tomography Pulmonary Angiography (CTPA), and V/Q Single Photon Emission Computed Tomography (SPECT)

Pulmonary embolism (PE) remains a diagnostic challenge. False negative testing exposes patient to the risk of potentially fatal recurrence. False positive testing exposes patients to potentially fatal unduly side effects of anticoagulants.

Current diagnostic strategies rely on the sequential use of pretest clinical probability, Ddimer test, and chest imaging. Two chest imaging modalities have been validated for PE diagnostic exclusion: Computed Tomography Pulmonary Angiography (CTPA) and planar V/Q scan. Main limitations of planar V/Q are the high proportion of non-conclusive results, therefore requiring additional testing and more complex diagnostic algorithms. Main limitations of CTPA are its higher radiation dose and contraindications (renal failure).

In a randomized trial that compared strategies based on CTPA and on planar V/Q scan, a 30% increase in the rate of PE diagnoses was found in the arm using CTPA, raising the hypothesis of over-diagnosing and over-treating PE when using CTPA.

V/Q Single Photon Emission CT (SPECT) is a new method of scintigraphic acquisition that has been reported to improve the diagnostic performances of the test, which could reduce the number of non-conclusive tests and allow simplified diagnostic algorithms.

The investigators hypothesize that a strategy based on V/Q SPECT could be an alternative to the two usual approaches responding rightly to the two mains issues and combining the advantages of CTPA (simplified diagnostic approach) and planar V/Q (no overdiagnosis, lower radiation exposure, no contraindication).

Although a recent survey showed that up to 70% of nuclear medicine centers perform SPECT rather than planar imaging for diagnosing PE, a diagnostic management outcome study, in which diagnostic decision would be made on the basis of a standardized algorithm based on the V/Q SPECT is lacking. Such a study needs to be conducted to ensure that the safety of diagnostic exclusion using a V/Q SPECT based strategy is non-inferior to that of previously validated strategies, and to verify that the use of V/Q SPECT does not lead to over-diagnosis.

Study Overview

Status

Terminated

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

611

Phase

  • Not Applicable

Contacts and Locations

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

Study Locations

  • Canada
      • Ottawa, Canada
        • Ottawa
  • France
      • Agen, France
        • Hopital Saint Esprit
      • Angers, France, 49933
        • CHU d'Angers
      • Brest, France, 29609
        • CHRU de Brest
      • Clermont-Ferrand, France
        • CHU Clermont Ferrand
      • Morlaix, France
        • CH des Pays de Morlaix
      • Paris, France, 75015
        • Hegp - Ap-Hp
      • Saint-Denis, France
        • CHU La Réunion
      • Saint-Étienne, France
        • CHU de Saint Etienne
      • Toulon, France
        • CH Toulon
  • Switzerland
      • Genève, Switzerland, 1205
        • Geneva University Hospital

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

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Outpatients with a clinically suspected PE (defined as an acute onset of new or worsening shortness of breath, chest pain, hemoptysis, presyncope, or syncope) without another obvious apparent cause.
  • High pretest clinical probability of PE or a non-high pretest clinical probability but a positive D-Dimer test.

Exclusion Criteria:

  • Age less than 18 years
  • Patients with already confirmed PE
  • Patients with a clinically suspected high-risk pulmonary embolism (hypotension or shock)
  • Use of therapeutic doses of anticoagulants for more than 48 hours
  • Other indication for long-term use of anticoagulants
  • Contraindication to contrast media (including renal insufficiency with a creatinine clearance lower than 30 ml/min)
  • Life expectancy less than 3 months
  • Unable/unwilling to give informed consent
  • Unlikely to comply with study follow-up
  • Ongoing pregnancy or breastfeeding

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

  • Primary Purpose: Diagnostic
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Planar V/Q-based strategy
Control arm
Device: Planar V/Q-based strategy
Strategy based on planar pulmonary scintigraphy
Active Comparator: CTPA-based strategy
Control arm
Device: CTPA-based strategy
Strategy based on pulmonary angiography
Experimental: V/Q SPECT-based strategy
Experimental arm
Device: V/Q SPECT-based strategy
Strategy based on pulmonary tomoscintigraphy

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Thromboembolic events rate in a 3 month follow-up period in patients left untreated after a negative diagnostic strategy.
Time Frame: 3 months
Rate of symptomatic objectively confirmed thromboembolic events during the 3-month follow-up period in patients left untreated after a negative diagnostic work-up in V/Q SPECT-based strategy in comparison with planar V/Q-based strategy and CTPA-based strategy.
3 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportion of PE diagnostic in each arm
Time Frame: 3 months
Proportion of patients deemed to have PE according to the strategy in each arm.
3 months
Proportion of additionnal tests required in each arm
Time Frame: 3 months
Proportion of patients for whom additional tests are requested in each arm.
3 months
Major bleeding incidence in each arm
Time Frame: 3 months
Incidence of major bleeding episodes in each arm.
3 months
Incidence and cause of death in each arm
Time Frame: 3 months
Incidence and cause of death in each arm
3 months

Collaborators and Investigators

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

Sponsor

University Hospital, Brest

Investigators

  • Study Director: Pierre-Yves Salaun, CHRU de Brest

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 (Actual)

April 10, 2017

Primary Completion (Actual)

December 17, 2024

Study Completion (Actual)

December 17, 2024

Study Registration Dates

First Submitted

November 28, 2016

First Submitted That Met QC Criteria

December 2, 2016

First Posted (Estimated)

December 6, 2016

Study Record Updates

Last Update Posted (Actual)

March 25, 2025

Last Update Submitted That Met QC Criteria

February 3, 2025

Last Verified

February 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SPECTACULAR - RB 16.068

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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