Role of CT in assessing pleural malignancy prior to thoracoscopy

Our plain-English summary of Role of CT in assessing pleural malignancy prior to thoracoscopy, by R.J. Hallifax, M. Haris, J.P. Corcoran, et al (Thorax, 2015).

The study

• Authors: R.J. Hallifax, M. Haris, J.P. Corcoran, S. Leyakathalikhan, E. Brown, D. Srikantharaja, A. Manuel, F.V. Gleeson, M. Munavvar, N.M. Rahman
• Journal: Thorax
• Published: 2015;70(2):192-3
• Cited by: 95 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The definitive diagnosis of pleural malignancy depends upon histological confirmation by pleural biopsy. CT is reported to have a high sensitivity and specificity for the diagnosis of malignant pleural disease, and is part of the routine diagnostic workup of these patients. The aim of this study was to assess the sensitivity and specificity of CT in detecting pleural malignancy prior to definitive histology obtained via thoracoscopy in a large cohort of patients with suspected malignant pleural disease. Retrospective review of thoracoscopies between January 2008 and January 2013 at two UK tertiary referral centres: Oxford and Preston. The histological results were compared with the CT reported diagnosis before the procedure. CT scan reports were assessed by independent respiratory physicians as to whether the radiologist concluded evidence of malignant pleural disease or benign features only. 211 (57%) of 370 patients included in the analysis had malignant disease: CT scans were reported as 'malignant' in 144, giving a sensitivity of 68% (95% CI 62% to 75%). Of the 159 patients with benign disease, 124 had CT scans reported as benign: specificity 78% (72% to 84%). The positive predictive value of a malignant CT report was 80% (75% to 86%), with a negative predictive value of 65% (58% to 72%). A significant proportion of patients being investigated for malignant disease will have malignancy despite a negative CT report. The use of CT alone in determining which patients should have invasive pleural biopsies should be re-evaluated, and further studies to define the diagnostic pathway are now required.

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In plain English

This retrospective review covered thoracoscopies done from 2008 to 2013 at two UK specialist centres, in Oxford and Preston. The authors tested how well written CT reports made beforehand identified pleural cancer. The reference was the final diagnosis: biopsy tissue for all but two patients, who were judged malignant from clinical and radiological progression during follow-up. Reports that only raised the possibility of malignancy were counted as benign. Of 370 cases analysed, 211 were malignant, including nine diagnosed during follow-up. At biopsy, 110 had mesothelioma and 92 had metastatic carcinoma. CT reports called 144 of the 211 malignant cases malignant (sensitivity 68.2%, 95% CI 62.0% to 74.5%) and 124 of 159 benign cases benign (specificity 78.0%, 71.5% to 84.4%). Of patients whose report was not malignant, 64.9% (58.2% to 71.7%) had benign disease. The authors concluded that among patients with pleural effusion investigated for suspected malignancy, about one in three whose CT report showed no pleural malignancy will in fact have malignancy. They concluded that using CT alone to decide who has a biopsy should be re-evaluated. The article does not discuss asbestos.

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: Retrospective review of thoracoscopy cases (diagnostic accuracy of CT reports compared with the final diagnosis)
• Who was studied: 370 patients (261 men, mean age 72.3 years) who had thoracoscopy for new pleural effusions at two UK tertiary referral centres (Churchill Hospital, Oxford, and Lancashire Teaching Hospitals, Preston), January 2008 to January 2013. Of 450 thoracoscopies, 47 were excluded for having no CT or no available formal CT report, and 33 because the biopsy was non-diagnostic or no biopsy was done.
• Exposure: No asbestos exposure was studied. The test examined was the radiologist's written report of a CT scan done before thoracoscopy. Reports 'highly suggestive or suggestive' of malignancy were classified as malignant. Reports of 'benign features', 'not conclusive' or 'raising the possibility of malignancy' were classified as benign.
• Main results:
  • On thoracoscopy biopsy, 202 patients had malignant pleural disease: 110 (54.5%) of 202 had mesothelioma and 92 (45.5%) had metastatic carcinoma from another primary.
  • Of 149 patients whose biopsy showed benign chronic inflammation and fibrosis, 9 (6.0%) were later diagnosed with malignancy during surveillance. Eight had mesothelioma: 6 proven on later biopsy and 2 by clinical and radiological progression only. One had metastatic adenocarcinoma from a lung primary. These 9 were counted as malignant, giving 211 of 370 (57.0%) malignant.
  • Of the 211 patients with malignant disease, 144 had CT scans reported as malignant: sensitivity 68.2% (95% CI 62.0% to 74.5%).
  • Of the 159 patients with benign disease, 124 had CT scans reported as benign: specificity 78.0% (95% CI 71.5% to 84.4%).
  • The positive predictive value of a 'malignant' CT report was 80.4% (74.6% to 86.3%). The negative predictive value was 64.9% (58.2% to 71.7%).
  • In the 326 patients with an unexplained new effusion, sensitivity was 69% (95% CI 62% to 76%) and specificity was 78% (72% to 85%). In the 44 patients with an effusion in the context of known or previous malignancy, sensitivity was 64% (95% CI 47% to 82%) and specificity was 75%.
• The authors' conclusion: The authors concluded that, with a negative predictive value of 65%, about one in three patients with pleural effusion whose CT report showed no evidence of pleural malignancy will in fact have malignancy. They also concluded that the use of CT alone to decide which patients should have invasive pleural biopsies should be re-evaluated, and that further studies to define the diagnostic pathway are required.

Topics

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

Medical terms in this study, explained in our Lexicon: Thoracoscopy, Pleural Biopsy, Histology, CT Scan.

Related studies

• Ultrasound-guided pneumothorax induction prior to local anaesthetic thoracoscopy — J.P. Corcoran, I. Psallidas, et al. (2015)
• Diagnostic value of medical thoracoscopy in pleural disease: a 6-year retrospective study — F.X. Blanc, K. Atassi, et al. (2002)
• Physician-based ultrasound-guided biopsy for diagnosing pleural disease — R.J. Hallifax, J.P. Corcoran, et al. (2014)
• Retrosternal and pleural "bridging" fibrosis mimicking malignancy in a patient exposed to asbestos — M.P. Debray, S. Marchand-Adam, et al. (2010)
• The diagnostic performance of routinely acquired and reported computed tomography imaging in patients presenting with suspected pleural malignancy — S. Tsim, D.B. Stobo, et al. (2017)
• An electrocautery pleural biopsy for the diagnosis of desmoplastic malignant mesothelioma during semirigid thoracoscopy — S. Sasada, K. Kawahara, et al. (2008)

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