Evaluation of the efficacy of the guideline on reading CT images of malignant pleural mesothelioma with reference CT films for improving the proficiency of radiologists

Our plain-English summary of Evaluation of the efficacy of the guideline on reading CT images of malignant pleural mesothelioma with reference CT films for improving the proficiency of radiologists, by H. Zhou, T. Tamura, Y. Kusaka, et al (European Journal of Radiology, 2013).

The study

• Authors: H. Zhou, T. Tamura, Y. Kusaka, N. Suganuma, P. Subhannachart, C. Vijitsanguan, W. Noisiri, K.G. Hering, M. Akira, H. Itoh, H. Arakawa, Y. Ishikawa, S. Kumagai, N. Kurumatani
• Journal: European Journal of Radiology
• Published: 2013;82(1):169-76
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Purpose: To assess the efficacy of the developed guideline on reading CT images of malignant pleural mesothelioma for improving radiologists' reading proficiency.

Materials And Methods: Three radiologists independently read the CT films of 22 cases including definite mesothelioma and non-mesothelioma cases at two times before and after studying the malignant pleural mesothelioma CT Guideline. The sensitivity and specificity for mesothelioma were calculated and compared between the 1st and 2nd trials. The kappa statistics was examined for agreement with experts for mesothelioma probability and for mesothelioma features recorded by three radiologists.

Results: After studying the mesothelioma CT Guideline, the sensitivity for mesothelioma shown by the three radiologists at the 2nd trial was 100%, 100% and 80%, which were higher than 80%, 85% and 60% at the 1st trial, respectively. The average kappa for agreement between radiologists and experts on dichotomized mesothelioma probability were 0.69 (good) at the 2nd trial vs. 0.38 (fair) at the 1st trial. The average kappa for the agreement with experts for each of 7 features by three radiologists were 0.52-0.80 at the 2nd trial, which were significantly higher than 0.34-0.58 at the 1st trial (Wilcoxon Signed Rank Test: P<0.01), and as to five features "unilateral pleural effusion", "nodular pleural thickening", "tumoral encasement of lung", "mediastinal pleural thickening", and "diminished lung", they achieved good agreement with average kappa of 0.61-0.80.

Conclusion: The developed mesothelioma CT Guideline was suggested to have substantial effect in improving the radiologists' proficiency for reading CT images of mesothelioma, and may contribute to accurate diagnosis of mesothelioma.

Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

In plain English

This study tested whether a guideline and reference CT films for reading malignant pleural mesothelioma (MPM) scans improved radiologists' reading. Three radiologists experienced with pneumoconiosis CT, who had seen few MPM cases, independently read films of 22 cases twice, at least three months apart: before and after studying the guideline and films. The films came from residents near the Kubota asbestos cement pipe factory in Amagasaki, Japan: 20 confirmed MPM and 2 pleural plaque cases. The article attributes the MPM to environmental asbestos exposure, mainly crocidolite. Afterwards, MPM sensitivity was 100%, 100% and 80% for the three radiologists, versus 80%, 85% and 60% before. One radiologist's specificity fell from 2 of 2 to 1 of 2 non-MPM cases. Average agreement with four experts on whether scans showed any CT probability of MPM, versus none, rose (kappa 0.38 to 0.69). Agreement on seven CT features also rose (P less than 0.01), though some individual scores fell. The authors concluded the guideline may help physicians recognise MPM features. They noted that having only two non-MPM cases may affect specificity.

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: Before-and-after reading study: three radiologists independently read the same 22 CT films twice, at least three months apart. The first reading was without the MPM-CT Guideline and MPM reference CT films, the second after studying them. Their readings were compared with a consensus of four experts.
• Who was studied: CT films of 22 cases: 20 definite MPM cases (13 male, 7 female) and 2 male pleural plaque cases. They were selected from 57 cases collected from citizens living near the Kubota asbestos cement pipe factory, Amagasaki City, Hyogo Prefecture, Japan. The readers were three radiologists experienced in pneumoconiosis CT who had not seen many MPM cases.
• Exposure: The intervention studied was the MPM-CT Guideline with MPM reference CT films. The article states, citing earlier work, that the cases' MPM was caused by environmental asbestos exposure (mainly crocidolite) from the Kubota factory.
• Main results:
  • Sensitivity for MPM (20 MPM cases) for the three radiologists was 100%, 100% and 80% at the 2nd trial, compared with 80%, 85% and 60% at the 1st trial.
  • For radiologist 1, specificity (2 non-MPM cases) was lower at the 2nd trial: 1/2 versus 2/2 per Table 2. Observed agreement with experts rose to 95.45% from 81.82%.
  • Average kappa for agreement between the radiologists and the experts on dichotomized MPM probability was 0.69 (good) at the 2nd trial versus 0.38 (fair) at the 1st trial. Dichotomized means CT probability Grades 2 to 4 (low, moderate or high) were grouped against Grade 1 (negative).
  • Weighted kappa for agreement with experts on the 4-point MPM probability scale was 0.32, 0.51 and 0.37 at the 2nd trial versus 0.24, 0.48 and 0.29 at the 1st trial.
  • Kappa values for agreement with experts on the 7 MPM CT features were significantly higher at the 2nd trial than at the 1st (Wilcoxon signed rank test, P less than 0.01). Average kappas across the three radiologists at the 2nd trial ranged from 0.52 to 0.80.
  • At the 2nd trial, five features showed good average agreement with experts: unilateral pleural effusion, nodular pleural thickening, mediastinal pleural thickening, tumoral encasement of lung and diminished lung.
  • Some individual scores fell. For radiologist 2, kappa for interlobar fissure thickening dropped from 0.73 to 0.55, and kappa for invasion dropped from 0.61 to 0.51.
  • For radiologist 3, kappa for unilateral pleural effusion dropped from 0.65 at the 1st trial to 0.49 at the 2nd trial.
• The authors' conclusion: The authors concluded that the three radiologists improved their proficiency in diagnosing MPM after studying the guideline. They also concluded that the guideline and reference films may help physicians recognise MPM features and contribute to early diagnosis in health surveillance.
• Limitations the authors state:
  • Only two non-MPM cases, both pleural plaque, were included, which may affect the specificity estimate.
  • Kappa is affected by prevalence. Non-MPM cases made up only 10% of cases, and many cases had intermediate probability grades; the authors say this made the 4-point weighted kappa low.
  • Two guideline features, contracted hemithorax and pleural mass, were left out of the comparison because they were added to the guideline later.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Mesothelioma, Pleural Effusion, Pleural Thickening.

Related studies

• Development of a guideline on reading CT images of malignant pleural mesothelioma and selection of the reference CT films — H. Zhou, T. Tamura, et al. (2012)
• Assessment of physicians' proficiency in reading chest radiographs for pneumoconiosis, based on a 60-film examination set with two factors constituting eight indices — T. Tamura, Y. Kusaka, et al. (2018)
• Comparison of digital with film radiographs for the classification of pneumoconiotic pleural abnormalities — T.C. Larson, D.B. Holiday, et al. (2012)
• Comparison of "B" readers' interpretations of chest radiographs for asbestos related changes — J.N. Gitlin, L.L. Cook, et al. (2004)
• Comparison of B readers' interpretations of chest radiographs for asbestos related changes — K.D. Rosenman (2004)
• Comparison of B readers' interpretations of chest radiographs for asbestos related changes — J.P. Kassirer (2004)

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