Prognostic value of SUVmax on 18F-fluorodeoxyglucose PET/CT scan in patients with malignant pleural mesothelioma

Our plain-English summary of Prognostic value of SUVmax on 18F-fluorodeoxyglucose PET/CT scan in patients with malignant pleural mesothelioma, by J.H. Lim, J.Y. Choi, Y. Im, et al (PloS One, 2020).

The study

• Authors: J.H. Lim, J.Y. Choi, Y. Im, H. Yoo, B.W. Jhun, B.H. Jeong, H.Y. Park, K. Lee, H. Kim, O.J. Kwon, J. Han, M.J. Ahn, J. Kim, S.W. Um
• Journal: PloS One
• Published: 2020;15(2):e0229299
• Cited by: 17 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Introduction: The maximum standardized uptake value (SUVmax) in 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) may be of prognostic significance for patients with malignant pleural mesothelioma (MPM). This retrospective study aimed to investigate the prognostic value of the SUVmax in patients with MPM.

Materials And Methods: Medical records were retrospectively reviewed for the patients who were diagnosed with histopathologically proven MPM between 2009 and 2018 at Samsung Medical Center. For each patient, SUVmax was calculated for the primary lesion on PET/CT. To determine optimal cutoff values for predicting mortality, receiver operating characteristic curves were used.

Results: Among the 54 study patients, 34 (63.0%) had epithelioid subtype, 13 (24.1%) had sarcomatoid or biphasic subtype, and 7 (13.0%) had mesothelioma, not otherwise specified (NOS). The median overall survival (OS) was 8.7 months, and the median SUVmax was 9.9. The median values of SUVmax were 5.5 in patients with epithelioid subtype, 11.7 in those with sarcomatoid/biphasic subtype, and 13.3 in those with NOS subtype (P = 0.003). The optimal cutoff values of SUVmax to predict mortality were 10.1 in all patients, and 8.5 in patients with epithelioid subtype. In multivariate analysis, SUVmax was significantly associated with overall survival in all patients (P = 0.003) and in patients with epithelioid subtype (P = 0.012), but not in those with non-epithelioid subtype.

Conclusions: SUVmax in PET/CT is an independent prognostic factor in patients with MPM, especially those with epithelioid subtype. The histologic subtype of MPM should be considered when evaluating the prognostic significance of SUVmax.

In plain English

This retrospective study reviewed the medical records of patients diagnosed with malignant pleural mesothelioma at Samsung Medical Center in Seoul, South Korea, between January 2009 and June 2018. Of 123 patients, 54 were included. The study measured SUVmax, which shows how strongly the tumor took up a radioactive sugar tracer on a PET/CT scan taken before treatment, and asked whether it was linked to survival. During follow-up, 30 of the 54 patients died. Median SUVmax was 5.5 in the epithelioid subtype, 11.7 in the sarcomatoid/biphasic subtype and 13.3 in the not otherwise specified subtype. In an analysis that also accounted for subtype, stage and chemotherapy, a high SUVmax was associated with shorter survival in all patients and in epithelioid patients, but not significantly in non-epithelioid patients. A second statistical check, using propensity scores, gave no statistically significant results. The authors concluded that SUVmax is an independent prognostic factor, especially in the epithelioid subtype. Because the sample was small and came from a single center, they said the results should be interpreted conservatively. Asbestos exposure was recorded, but data were insufficient for 19 patients.

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 medical records (single-center prognostic study)
• Who was studied: 54 patients with histopathologically proven malignant pleural mesothelioma who had baseline 18F-FDG PET/CT, selected from 123 patients diagnosed between January 2009 and June 2018 at Samsung Medical Center, Seoul, South Korea. Median age was 64 and 75.9% were men. 34 had epithelioid subtype, 10 sarcomatoid, 3 biphasic and 7 not otherwise specified.
• Exposure: The factor studied was SUVmax of the primary tumor on 18F-FDG PET/CT performed before surgery or chemotherapy. Asbestos exposure was recorded as a clinical characteristic: yes in 15 patients (27.8%), no in 20 (37.0%) and unknown in 19 (35.2%). Fiber types were not reported.
• Main results:
  • 30 of 54 patients (55.6%) died during a median follow-up of 8.7 months. The median overall survival in the body of the article was 12.6 months.
  • Median SUVmax was significantly lower in the epithelioid subtype (5.5) than in the sarcomatoid/biphasic subtype (11.7) or the not otherwise specified subtype (13.3).
  • The optimal SUVmax cutoff for predicting death was 10.1 in all patients (AUC 0.681), 8.5 in epithelioid patients (AUC 0.611) and 10.3 in non-epithelioid patients (AUC 0.453).
  • In all 54 patients, in multivariate analysis, SUVmax above the cutoff remained significantly associated with overall survival (hazard ratio 3.77, 95% CI 1.58–9.01, P = 0.003). Histologic subtype, stage and chemotherapy also remained significant.
  • In the 34 epithelioid patients, in multivariate analysis, SUVmax above 8.5 was associated with overall survival (hazard ratio 5.65, 95% CI 1.45–21.98, P = 0.012).
  • In the 20 non-epithelioid patients, SUVmax was not associated with overall survival (univariate P = 0.266; multivariate hazard ratio 2.83, 95% CI 0.79–10.1, P = 0.111).
  • With propensity score adjustment, the SUVmax hazard ratios were 1.83 (0.86–3.87; P = 0.114) for all patients, 2.53 (0.83–7.67; P = 0.101) for epithelioid patients and 1.84 (0.59–5.75; P = 0.295) for non-epithelioid patients. None was statistically significant.
• The authors' conclusion: The authors concluded that SUVmax on PET/CT is an independent prognostic factor in malignant pleural mesothelioma, especially in the epithelioid subtype, and that histologic subtype should be considered when evaluating its prognostic significance.
• Limitations the authors state:
  • The small sample size and limited number of events may make the multivariable model unstable.
  • The retrospective design and single-institution population may limit generalization.
  • Because the propensity score results were not significant, the authors said the multivariable results should be interpreted conservatively.
  • Histologic subtype was not specifically defined in seven patients.
  • Asbestos exposure data were insufficient for 19 patients (35.2%).

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: CT Scan, Pleural Mesothelioma, Epithelioid, Sarcomatoid, Biphasic Mesothelioma, Mesothelioma, Median Overall Survival, Multivariate Analysis.

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• Prognostic value of pretreatment volume-based quantitative 18F-FDG PET/CT parameters in patients with malignant pleural mesothelioma — K. Kitajima, H. Doi, 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)
• 18F-Fluorodeoxyglucose PET/CT and dynamic contrast-enhanced MRI as imaging biomarkers in malignant pleural mesothelioma — D.O. Hall, C.E. Hooper, et al. (2018)
• 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)

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