18F-FDG PET/CT in the management of patients with malignant pleural mesothelioma being considered for multimodality therapy: experience of a tertiary referral center

Our plain-English summary of 18F-FDG PET/CT in the management of patients with malignant pleural mesothelioma being considered for multimodality therapy: experience of a tertiary referral center, by H.S. Elliott, U. Metser, M. de Perrot, et al (The British Journal of Radiology, 2018).

The study

• Authors: H.S. Elliott, U. Metser, M. de Perrot, J. Cho, P. Bradbury, P. Veit-Haibach, D. Hussey, T. Noam
• Journal: The British Journal of Radiology
• Published: 2018;91(1086):20170814
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objective: To compare the N- and M-staging accuracy of PET vs CT, as per the American Joint Committee on Cancer (AJCC) eighth edition in patients with malignant pleural mesothelioma (MPM) being considered for multimodality therapy in a tertiary referral center. A secondary aim was to assess survival outcome of patients chosen for surgical management after PET.

Methods: A retrospective, single institution comparison of PET and CT was performed in patients with histologically proven MPM being considered for multimodality therapy. Performance of each modality in identifying nodal category and presence or absence of distant metastases was abstracted from electronic patient records. The standard of reference was surgical histopathology for nodal stage and histopathology or clinical and imaging follow-up of >3 months for distant metastases.

Results: There were 101 eligible patients with complete data sets; 82 males, 19 females with a mean age of 66.6 years (range: 39-85). Most patients (n = 68) had epithelioid histology. Surgery was performed in 61/101 patients (60.4%), most of whom had multimodality therapy. Nodal category was concordant to surgical histopathology in 38/60 patients (63.3%) on PET, compared to 27/60 (45%) on CT (p = 0.001). For detection of ≥N1 disease only, PET and CT correctly staged 15/37 patients (40.5%) and 8/37 (21.6%), respectively (p = 0.023). Distant metastases were identified uniquely on PET in eight patients and on CT only in one patient. Overall, PET and CT correctly identified 11/12 (91.6%) and 4/12 (33.3%) patients with distant metastases, respectively (p = 0.0391).

Conclusion: PET identifies significantly more patients with nodal or distant metastatic disease than CT and may contribute to more appropriate selection of patients with MPM for surgery or multimodality therapy. Advances in knowledge: In patients with MPM, fludeoxyglucose-PET/CT detects significantly more patients with distant metastases than CT. PET/CT can help in the selection of patients with MPM who would benefit from surgery or multimodality therapy.

In plain English

This retrospective, single-center study compared two scans used to stage malignant pleural mesothelioma: contrast-enhanced CT and FDG PET/CT (called PET). It included 101 patients being considered for multimodality therapy whose PET scans were done between November 2007 and March 2016. The article does not report asbestos exposure. In 60 surgical patients whose lymph nodes were examined, PET staged the nodes correctly in 38/60 (63.3%) and CT in 27/60 (45%). In the 37 patients whose nodes contained cancer, PET correctly staged 15 (40.5%) and CT 8 (21.6%). Twelve of the 101 patients had distant spread. PET correctly identified 11 of them and CT 4. Of the 61 patients who had surgery, 29 (47.5%) survived at least 2 years. The authors concluded that PET identifies significantly more patients with nodal or distant metastatic disease than CT and may help select patients for surgery or multimodality therapy. They noted that the study was retrospective and single-center, relied on imaging reports rather than two independent readers, and had incomplete survival data.

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: Single-institution retrospective study comparing CT with FDG PET/CT for staging
• Who was studied: 101 patients with malignant pleural mesothelioma (82 males, 19 females; median age 69, range 39 to 85) being considered for multimodality therapy at a tertiary referral center. The authors are at University of Toronto hospitals. PET scans were done between November 2007 and March 2016.
• Exposure: Not an asbestos exposure study. The study compared two staging tests: contrast-enhanced CT of the chest and abdomen, and FDG PET/CT. All patients had a histological diagnosis of malignant pleural mesothelioma.
• Main results:
  • Among 60 surgical patients with lymph node pathology, nodal category matched pathology in 38/60 (63.3%) on PET and 27/60 (45%) on CT (p = 0.001).
  • For patients with N1 or higher nodal disease at pathology, PET correctly staged 15/37 (40.5%) and CT 8/37 (21.6%) (p = 0.023).
  • 12/101 patients (11.9%) had distant metastases by the standard of reference. PET correctly identified 11/12 (91.6%) and CT 4/12 (33.3%) (p = 0.0391).
  • In a lesion-level analysis, PET correctly identified 15/16 (93.8%) distant metastases and CT 4/16 (25%) (p = 0.0002).
  • Among the 61 surgically treated patients, 47/61 died, with a median survival time of 16 months (range 3 to 76), and 29/61 (47.5%) survived at least 2 years.
  • Among the 40 patients not treated surgically, 20/40 (50%) were known to have died, with a median survival time of 10 months (range 1 to 30). The other 20/40 were lost to follow-up.
• The authors' conclusion: The authors concluded that FDG PET/CT identifies significantly more patients with nodal or distant metastatic disease than CT and may contribute to more appropriate selection of patients with malignant pleural mesothelioma for surgery or multimodality therapy.
• Limitations the authors state:
  • Retrospective design using data from a single institution.
  • The data came from imaging reports, and the scans were not interpreted by two independent readers.
  • Surgical nodal staging was available for only 60% of the cohort.
  • Survival data were incomplete, especially for non-surgical patients, so survival could not be compared between surgical and non-surgical groups.
  • The study could not document the downstream effect of PET on patient outcome.

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, Multimodal Therapy, Staging, AJCC, Histopathology, Epithelioid, Histology.

Related studies

• Role of integrated 18-fluorodeoxyglucose position emission tomography-computed tomography in patients surveillance after multimodality therapy of malignant pleural mesothelioma — C. Tan, S. Barrington, et al. (2010)
• Volume-based parameter of 18)F-FDG PET/CT in malignant pleural mesothelioma: prediction of therapeutic response and prognostic implications — H.Y. Lee, S.H. Hyun, et al. (2010)
• 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 value of 18F-FDG standard uptake value by integrated PET/CT in the staging of malignant pleural mesothelioma — G. Genestreti, A. Moretti, et al. (2012)
• Whole-Body MRI: Comparison of Its Capability for TNM Staging of Malignant Pleural Mesothelioma With That of Coregistered PET/MRI, Integrated FDG PET/CT, and Conventional Imaging — Y. Ohno, M. Yui, et al. (2019)
• Diagnostic Ability of FDG-PET/CT in the Detection of Malignant Pleural Effusion — R. Nakajima, K. Abe, et al. (2015)

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