Does positron emission tomography offer prognostic information in malignant pleural mesothelioma?

Our plain-English summary of Does positron emission tomography offer prognostic information in malignant pleural mesothelioma?, by S. Sharif, I. Zahid, T. Routledge, et al (Interactive Cardiovascular and Thoracic Surgery, 2011).

The study

• Authors: S. Sharif, I. Zahid, T. Routledge, M. Scarci
• Journal: Interactive Cardiovascular and Thoracic Surgery
• Published: 2011;12(5):806-11
• Type of article: Review
• Cited by: 30 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether positron emission tomography is useful in the diagnosis and prognosis of malignant pleural mesothelioma (MPM). Altogether 136 papers were found using the reported search, of which 15 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that fluorodeoxyglucose-positron emission tomography (FDG-PET) accurately differentiates benign from malignant pleural disease, helps detect recurrence and provides prognostic information in terms of staging, survival and mortality. Eleven studies evaluated the role of FDG-PET in the diagnosis and prognosis of MPM. Malignant disease had a higher standardised uptake value (SUV) (6.5 ± 3.4 vs. 0.8 ± 0.6; P < 0.001) than benign pleural disease. Shorter median survival (9.7 vs. 21 months; P = 0.02) was associated with high SUV (>10) than low SUV (<10). PET accurately upstaged 13% and downstaged 27% of cases initially staged with computed tomography (CT). In patients undergoing chemotherapy, higher total glycolytic volume led to a lower median survival (4.9 vs. 11.5 months; P = 0.09), while a decline in FDG uptake was associated with a longer time to tumour progression (14 vs. 7 months; P = 0.02). Four studies observed the role of FDG-PET-CT in the diagnosis and prognosis of MPM. SUV was found to be higher in MPM compared to benign pleural disease (6.5 vs. 0.8; P < 0.001). A higher SUV(max) was observed in primary pleural lesions of metastatic (7.1 vs. 4.7; P = 0.003) compared to non-metastatic disease. Patients who underwent surgery had equivalent survival to those excluded based on scan results (20 vs. 12 months; P = 0.3813). One study compared the utility of PET and PET-CT in the diagnosis and prognosis of mesothelioma. PET-CT was found to be more accurate than PET in terms of staging (P < 0.05) disease. Overall, PET accurately diagnoses MPM, predicts survival and disease recurrence. It can guide further management by predicting the response to chemotherapy and excluding surgery in patients with extrathoracic disease. Combined PET-CT has additional benefits in accurately staging disease.

In plain English

This article was a 'best evidence topic', a structured review of published studies, not new research. The authors searched Medline from 1950 to August 2010, found 136 papers, and chose 15 as the best evidence on whether PET scanning (mostly with the tracer FDG, sometimes combined with CT as PET-CT) helps diagnose, stage and predict outcome in malignant pleural mesothelioma. In one reviewed study of 31 patients, PET-CT distinguished mesothelioma from benign pleural disease, including benign asbestos-related pleural effusion and diffuse pleural thickening, with 88.2% sensitivity, 92.9% specificity and 90.3% overall accuracy. In another, of 137 patients, those with high tracer uptake (SUV above 10) had shorter median survival than those with low uptake (9.7 vs. 21 months). One study of 15 patients reported that PET upstaged 13% and downstaged 27% of cases compared with CT. One study found PET-CT more accurate than PET for staging. The authors concluded that PET is a useful tool to identify and stage mesothelioma and to predict survival, that PET-CT gave better results than PET alone, and that further prospective studies are needed.

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: Review ('best evidence topic'): structured literature search and tabulation of 15 published studies
• Who was studied: 15 published studies selected from 136 papers found in a Medline search covering 1950 to August 2010. The reviewed studies were of patients with malignant pleural mesothelioma, some also including patients with benign pleural disease. Study sizes ranged from 15 to 456 patients. The studies came from the USA, Japan, Australia, Italy, Turkey, the UK and Germany.
• Exposure: This is not a study of asbestos exposure. What was reviewed was imaging with FDG-PET and combined PET-CT, compared with CT and MRI. Asbestos appears only in one reviewed study, which compared mesothelioma with benign asbestos-related pleural effusion and diffuse pleural thickening.
• Main results:
  • Yildirim et al. (31 patients: 17 with mesothelioma, 14 with benign pleural disease): PET-CT detected mesothelioma with sensitivity 88.2%, specificity 92.9% and overall accuracy 90.3%. Mean SUVmax was 6.5 (plus or minus 3.4) in mesothelioma vs. 0.8 (plus or minus 0.6) in benign disease, p less than 0.001.
  • Flores et al. 2006 (137 patients with mesothelioma): high SUV (above 10) was associated with shorter median survival than low SUV (below 10), 9.7 vs. 21 months (p = 0.02), and with 1.9 times greater risk of death (p less than 0.01).
  • Bernard et al. (22 patients with mesothelioma): cumulative survival at 12 months was 17% in patients with high SUV (above 4.03) vs. 86% in those with low SUV (p less than 0.01).
  • Ceresoli et al. (20 patients receiving chemotherapy): patients whose FDG uptake fell by 25% or more (responders) had a longer median time to tumour progression than non-responders, 14 vs. 7 months (p = 0.02). The difference in survival had p = 0.07.
  • Francis et al. (23 patients scanned before and after one cycle of chemotherapy): a reduction in total glycolytic volume was predictive of improved survival (p = 0.015).
  • Nanni et al. (15 patients): PET and CT staging agreed in 60%. PET upstaged 13% and downstaged 27% of patients, leading to a change in management in 20%.
  • Wilcox et al. (35 patients): 13 patients were upstaged after PET-CT. Survival did not differ significantly between patients who had extrapleural pneumonectomy (n=8) and those excluded from surgery based on scan results (n=14), 20 vs. 12 months. The p-value is printed as 0.3812 in the text and 0.3813 in the table.
  • Lee et al. (46 patients): PET-CT detected metastases in 9 patients, 8 of them previously undetected. Primary pleural lesions in patients with metastases had higher mean SUVmax (7.1 vs. 4.7, p = 0.003) and shorter survival (4 vs. 8 months, p less than 0.05) than those without metastases.
  • Tan et al. (25 patients after multimodality therapy): PET-CT detected 17 of 18 recurrences (sensitivity 94%) and correctly identified no recurrence in 7 patients (specificity 100%).
  • Plathow et al. (54 patients with epithelial mesothelioma): PET-CT was more accurate than PET for staging (p less than 0.05) and had 100% sensitivity and specificity for all disease stages.
• The authors' conclusion: The authors concluded that PET is a useful diagnostic tool to identify and stage malignant pleural mesothelioma and to distinguish it from benign pleural disease. They also concluded that it is useful for predicting survival and detecting metastases and recurrence, and that PET-CT gave better diagnostic results than PET alone.
• Limitations the authors state:
  • The authors stated that further prospective studies are needed to refine the role of PET and PET-CT in different settings of mesothelioma.

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, Thoracic Surgery, Prognosis, Staging, Median Survival, Chemotherapy, PET-CT, Mesothelioma.

Related studies

• Integrated positron emission tomography-computed tomography does not accurately stage intrathoracic disease of patients undergoing trimodality therapy for malignant pleural mesothelioma — J. Pilling, J.A. Dartnell, et al. (2010)
• Prognostic and predictive role of [18 F]fluorodeoxyglucose positron emission tomography (FDG-PET) in patients with unresectable malignant pleural mesothelioma (MPM) treated with up-front pemetrexed-based chemotherapy — P.A. Zucali, E. Lopci, et al. (2017)
• Clinical value of fluorodeoxyglucose-positron emission tomography/computed tomography in differentiation of malignant mesothelioma from asbestos-related benign pleural disease: an observational pilot study — H. Yildirim, M. Metintas, et al. (2009)
• eComment: What is the best way to diagnose and stage malignant pleural mesothelioma? — S. Cafarotti, V. Porziella, et al. (2011)
• Contribution of positron emission tomography in pleural disease — B. Duysinx, J.L. Corhay, et al. (2010)
• 18-Fluorodeoxyglucose positron emission tomography as a tool for response prediction in solid tumours — D.J. De Maeseneer, B. Lambert, et al. (2010)

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