The Value of PET-CT in Pleural Effusions

The Diagnostic Power of 18F-FDG PET-CT Scanning for Discriminating Malignant From Non-malignant Causes in Unilateral Pleural Effusions

The investigators aim is to asses the diagnostic power of 18F-FDG PET-CT in discriminating malignant from nonmalignant causes in patients with a recurrent unilateral pleural effusion of unknown origin.

Study Overview

• Status: Completed
• Conditions: Pleural Effusion, Malignant

Detailed Description

The investigators follow the STARD 2015 guideline for reporting diagnostic accuracy studies.

The investigators will review the hospital's administrative database of patients who underwent a thoracocentesis from January 2013 to January 2015. Patients at Department of Respiratory Medicine, Zealand University Hospital, Roskilde and Department of Respiratory Medicine, Naestved Hospital, Region Zealand, Denmark (two large respiratory centres with specialised functions) is eligible for inclusion. Patients are included irrespective of cytology and chemical analysis.

The investigators will review the patients' medical records and images retrospectively. To reduce the number of false negatives, the investigators complete a 1-year follow-up.

Patients older than 16 years are included, irrespective of smoking history and comorbidities, if both thoracocenteses, chest x-ray, a CT-scanning and a PET-CT scanning is performed. Exclusion criteria are previously diagnosed lung cancer, thoracic malignancy or incomplete data.

Classification of results The investigators chose the combination of investigations recommended by the internationally acknowledged BTS guideline, which is endorsed by the Danish Society of Respiratory Medicine. Thoracocentesis, chest x-ray, CT findings and PET-CT findings is categorized as either normal (i.e. not suggestive of any aetiology of the unilateral pleural effusion), suggestive of other lung pathology or suggestive of malignancy (i.e. representing a possible aetiology of the unilateral pleural effusion).

The thoracocentesis is classified as malignant if cytological examination revealed malignant cells. The chest x-ray is classified as malignant if suspicion of malignant disease is not rejected. The CT findings are classified as malignant according to Leung et. al. for pleural abnormalities (circumferential pleural thickening, nodular pleural thickening, parietal pleural thickening > 1 cm and mediastinal pleural involvement) and The Fleischner Society for parenchymal abnormalities (nodules > 8 mm). The PET-CT findings are classified as malignant if any findings suspicious for malignancy.

CT and PET-CT images, as well as the scan reports by the radiologist and the nuclear medicine physician, is reviewed by two experienced pulmonologists. They are blinded to all patient information, including final diagnosis.

The final diagnosis, the reference standard, is extracted from the patients' medical records. When no diagnosis is found, two investigators agree on a consensus diagnosis based on all investigation results. If no reasonable diagnosis can be established based on the findings, the patient case is categorized as having no final diagnosis. These cases are treated as a worst-case scenario, i.e. patients with a malignant disease are treated as false negative, and patients without malignant disease are treated as false positive.

Statistics Data are presented as frequencies and/or mean ± standard deviation (SD). Test characteristics were compared using McNemar's test with Bonferroni correction (two-sided level of significance < o.o5). Diagnostic power of thoracocentesis, chest x-ray, CT-scanning, PET-CT scanning and the combination are calculated. Diagnostic power is defined as true positive, true negative, false positive, false negative, sensitivity, specificity, likelihood ratio+, likelihood ratio-, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy (TP+TN)/(TP+FP+TN+FN).

The combined sensitivity will be calculated using the formula:

Sensitivitytest A + Sensitivitytest B + Sensitivitytest … - (Sensitivitytest A x Sensitivitytest B x Sensitivitytest …)

The combined specificity will be calculated using the formula:

Specificitytest A x Specificitytest B x Specificitytest… Data were analyzed using STATA (StataCorp LLC, Version 15.0, College Station, Texas, USA).

• Study Type: Observational
• Enrollment (Actual): 112

Contacts and Locations

Study Locations

• Denmark
  • Naestved, Denmark, 4700
    • Naestved Hospital
  • Næstved, Denmark, 4700
    • Naestved Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

All patients with a unilateral pleural effusion of unknown origin examined with the above

Description

Inclusion Criteria:

• Thoracocentesis
• Chest X-ray
• CT scanning
• PET-CT scanning

Exclusion Criteria:

• Missing data
• Lung cancer
• Thoracic malignancies

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Retrospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sensitivity PET-CT	TP / (TP + FN)	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
CT-Specificity	TN / (TN+FP)	1 year
PET-CT-Specificity	TN / (TN+FP)	1 year
CT-Sensitivity	TP / (TP + FN)	1 year
Comparison of the diagnostic power	McNemars' test with Bonferroni	1 year
CT-Likelihood ratio+	LR+ = sensitivity / (1-specificity)	1 Year
PET-CT-Likelihood ratio+	LR+ = sensitivity / (1-specificity)	1 Year
CT-Likelihood ratio-	LR- = (1-sensitivity) / specificity	1 year
PET-CT-Likelihood ratio-	LR- = (1-sensitivity) / specificity	1 year
CT-positive predictive value	PPV =TP / (TP+ FP)	1 year
PET-CT-positive predictive value	PPV =TP / (TP+ FP)	1 year
CT-negative predictive value	TN/ (TN + FN)	1 year
PET-CT-negative predictive value	TN/ (TN + FN)	1 year
CT-Diagnostic accuracy	(TP+TN) / (TP+TN+FP+FN)	1 year
PET-CT-Diagnostic accuracy	(TP+TN) / (TP+TN+FP+FN)	1 year

Collaborators and Investigators

• Sponsor: Naestved Hospital

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2017
• Primary Completion (Actual): January 31, 2018
• Study Completion (Actual): January 30, 2019

Study Registration Dates

• First Submitted: August 30, 2017
• First Submitted That Met QC Criteria: September 1, 2017
• First Posted (Actual): September 6, 2017

Study Record Updates

• Last Update Posted (Actual): December 17, 2020
• Last Update Submitted That Met QC Criteria: December 15, 2020
• Last Verified: December 1, 2020

More Information

Terms related to this study

• Keywords: Computed tomography; Sensitivity; Specificity; Positron emission thomography
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Neoplasms; Neoplasms by Site; Pleural Diseases; Respiratory Tract Neoplasms; Thoracic Neoplasms; Pleural Neoplasms; Pleural Effusion, Malignant; Pleural Effusion
• Other Study ID Numbers: PET-CT in UPE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No