Malignant pleural mesothelioma: value of CT and MR imaging in predicting resectability

Our plain-English summary of Malignant pleural mesothelioma: value of CT and MR imaging in predicting resectability, by E.F. Patz, K. Shaffer, D.R. Piwnica-Worms, et al (AJR. American Journal of Roentgenology, 1992).

The study

• Authors: E.F. Patz, K. Shaffer, D.R. Piwnica-Worms, M. Jochelson, M. Sarin, D.J. Sugarbaker, R.D. Pugatch
• Journal: AJR. American Journal of Roentgenology
• Published: 1992;159(5):961-6
• Cited by: 152 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: Our objective was to determine if CT or MR imaging findings could be used to accurately predict resectability in patients with biopsy-proved malignant pleural mesotheliomas.

Subjects And Methods: CT and MR findings in 41 consecutive patients with malignant mesotheliomas who were referred to the thoracic surgery clinic for extrapleural pneumonectomy were studied by thoracic radiologists before surgery. Review of radiologic studies focused on local invasion of three separate regions: the diaphragm, chest wall, and mediastinum. Results of all imaging examinations were carefully correlated with intraoperative, gross, and microscopic pathologic findings.

Results: After radiologic and clinical evaluation, 34 patients (83%) had thoracotomy; 24 of these had tumors that were resectable. The sensitivity was high (> 90%) for both CT and MR in each region. Specificity, however, was low, probably because of the small number of patients with unresectable tumors.

Conclusion: CT and MR provided similar information on resectability in most cases. Sensitivity was high for both procedures. Because CT is more widely available and used, we suggest it as the initial study when determining resectability. In difficult cases, important complementary anatomic information can be derived from MR images obtained before surgical intervention.

In plain English

This study asked whether CT and MR scans could predict which patients with malignant pleural mesothelioma could have their tumor removed by extrapleural pneumonectomy, an operation in which the pleura, lung and diaphragm are removed together. Only the article's closing pages were available, so the patient numbers and detailed results could not be checked. The authors reported that both CT and MR had high sensitivity in all three regions examined: the diaphragm, the chest wall and the mediastinum. Specificity was practically impossible to assess because few patients had unresectable tumors, and the two scan types could not be compared statistically. A clear fat plane and a smooth contour below the diaphragm were the most reliable signs that a tumor could be removed. MR was slightly better than CT at the chest wall. In the mediastinum, tumor infiltrating soft tissue with loss of normal fat planes was the most reliable sign that it could not be removed. The authors suggested CT first, with MR as a complement in questionable cases.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Clinical imaging study comparing CT and MR findings for predicting surgical resectability of malignant pleural mesothelioma. The methods section is not in the available text.
• Who was studied: Patients with malignant pleural mesothelioma seen in a thoracic clinic as candidates for surgery. The number of patients, the place and the dates are not given in the available text.
• Exposure: No asbestos exposure was studied. The study evaluated CT and MR imaging before surgery, with CT done first.
• Main results:
  • In all patients studied, both MR and CT had high sensitivity in all three regions (diaphragm, chest wall and mediastinum).
  • Specificity could practically not be assessed because few patients had unresectable tumors.
  • The authors could not compare CT and MR statistically because of the small numbers.
  • At the diaphragm, the most reliable findings that a tumor could be removed were a clear fat plane between the lower diaphragm surface and the abdominal organs, and a smooth lower diaphragm contour.
  • At the chest wall, MR findings were slightly better than CT findings for predicting resectability.
  • In the mediastinum, the most reliable sign of an unresectable tumor on either CT or MR was soft-tissue infiltration with loss of normal fat planes.
  • In two patients, tumors that were thought from imaging to be unresectable turned out to be resectable. The authors attributed the MR findings in these cases to phase-encoding artifacts.
  • The authors found no difference in predicting resectability between contrast-enhanced and unenhanced CT scans.
• The authors' conclusion: The authors suggested CT as the first imaging study for patients considered for resection. They proposed MR as the final examination before surgery to complement CT, particularly in questionable cases.
• Limitations the authors state:
  • The number of cases was small and statistical analysis was limited.
  • Patients were a select group referred as surgical candidates. This selection bias distorted the spectrum of disease and limited patient numbers.
  • MR was done closer to surgery than CT, so tumor progression in between may have biased the comparison. The authors did not believe this affected the results.
  • The lack of contrast-enhanced CT scans may have limited detection of local invasion.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Biopsy, Malignant Mesothelioma, Thoracic Surgery, Extrapleural Pneumonectomy (EPP), Diaphragm, Mediastinum, Thoracotomy.

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