FDG PET/CT Response Evaluation in Malignant Pleural Mesothelioma Patients Treated with Talc Pleurodesis and Chemotherapy

Our plain-English summary of FDG PET/CT Response Evaluation in Malignant Pleural Mesothelioma Patients Treated with Talc Pleurodesis and Chemotherapy, by G. Genestreti, A. Moretti, S. Piciucchi, et al (Journal of Cancer, 2012).

The study

• Authors: G. Genestreti, A. Moretti, S. Piciucchi, N. Giovannini, R. Galassi, E. Scarpi, M.A. Burgio, D. Amadori, S. Sanna, V. Poletti, F. Matteucci, G. Gavelli
• Journal: Journal of Cancer
• Published: 2012;3:241-5
• Cited by: 22 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Purpose: Talc pleurodesis (TP) is employed worldwide for the management of persistent pneumothorax or pleural effusion, particularly of malignant origin. However, there are very little available data on (18)F-fluorodeoxyglucose positron-emission tomography/computed tomography ((18)F FDG PET/CT) response evaluation in malignant pleural mesothelioma (MPM) patients treated with TP and chemotherapy.

Methods: Patients with histologically confirmed MPM underwent TP and FDG PET/CT staging and restaging after 3-4 courses of chemotherapy. All patients fasted and received a dose of 5.18 MBq (18)F-FDG per kilogram of body weight. Whole-body emission scans were acquired with and without Ordered Subset Expectation Maximization (OSEM) iterative reconstruction algorithm.

Results: From January 2004 to March 2010, 8 patients with biopsy confirmed MPM (7 epithelial, 1 biphasic), with a median age of 65 years (range: 54-77), were evaluated. Median follow-up was 31 months (range: 4-44). After TP treatment, there was a mean interval of 14 days (range: 9-22) and 125 days (range: 76-162) between FDG PET/CT staging and restaging. According to modified RECIST and EORTC criteria, there was a concordance between the radiologic and metabolic SUVmean and SUVmax responses in 6 (75%) and 3 (37.5%) patients, respectively.

Conclusion: TP produces an increased FDG PET uptake which may interfere with the post-chemotherapy disease evaluation. In our case series, the metabolic response measured by SUVmean seems to be in better agreement with the radiologic response compared to the SUVmax.

In plain English

This short report described a retrospective case series of 8 patients with malignant pleural mesothelioma (7 epithelioid, 1 mixed subtype) evaluated between January 2004 and March 2010; the authors worked at institutions in Forlì and Meldola, Italy. The article did not discuss asbestos exposure. Each patient's diagnosis was confirmed by biopsy during talc pleurodesis, a procedure in which sterile talc is instilled into the pleural cavity, causing irritation, inflammation and ultimately pleural fibrosis. Each patient then had an FDG PET/CT scan. All received 3 or 4 courses of pemetrexed-based chemotherapy before a second scan. The authors compared tumor response judged from CT images with response judged from tracer uptake, which they measured two ways (SUVmean and SUVmax). The SUVmean results agreed with the CT judgment in 6 of 8 patients (75%). The SUVmax results agreed in 3 of 8 (37.5%). The authors noted this difference did not reach statistical significance. They concluded that talc pleurodesis increases FDG uptake, which may interfere with evaluating disease after chemotherapy, and that SUVmean seemed to agree better with CT. They attributed the lack of significance probably to the small number of cases and called for a larger prospective study.

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 case series
• Who was studied: 8 patients with biopsy-confirmed malignant pleural mesothelioma (7 epithelioid, 1 mixed; 6 men, 2 women; median age 65, range 54 to 77), evaluated from January 2004 to March 2010. The authors' affiliations were in Forlì and Meldola, Italy.
• Exposure: Not an asbestos exposure study. The patients had talc pleurodesis followed by pemetrexed-based chemotherapy: 3 with carboplatin, 4 with cisplatin, 1 with pemetrexed only; median 3.5 courses, range 3 to 4.
• Main results:
  • Agreement between the CT (radiologic) response and the metabolic response was 6 of 8 patients (75%) using SUVmean and 3 of 8 patients (37.5%) using SUVmax
  • After talc pleurodesis, the mean interval was 14 days (range 9 to 22) to the staging scan and 125 days (range 76 to 162) to the restaging scan
  • 7 patients (88%) had stage I disease and 1 (12%) had stage II disease
  • The better agreement of SUVmean with the CT evaluation did not reach statistical significance
• The authors' conclusion: The authors concluded that talc pleurodesis produces increased FDG PET uptake that may interfere with post-chemotherapy disease evaluation. They also concluded that in their case series the metabolic response measured by SUVmean seemed to agree better with the radiologic response than SUVmax did.
• Limitations the authors state:
  • The number of cases was small, which the authors said probably explains the lack of statistical significance. They said a larger prospective study is required to confirm their hypothesis.

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Talc Pleurodesis, Chemotherapy, Pneumothorax, Pleural Effusion, Staging, Biopsy, Biphasic Mesothelioma.

Related studies

• Fluorodeoxyglucose versus Choline Positron Emission Tomography/Computed Tomography Response Evaluation in Two Malignant Pleural Mesothelioma Patients Treated with Talc Pleurodesis and Neoadjuvant Chemotherapy — K. Kitajima, T. Nakamichi, et al. (2018)
• Life expectancy of patients with malignant pleural effusion treated with video-assisted thoracoscopic talc pleurodesis — T. Laisaar, V. Palmiste, et al. (2006)
• Comparison of video-assisted pleurectomy/decortication surgery plus hyperthermic intrathoracic chemotherapy with VATS talc pleurodesis for the treatment of malignant pleural mesothelioma: A pilot study — M. Migliore, M. Fiore, et al. (2023)
• Response to letters regarding "Cosmetic talc as a risk factor for pleural mesothelioma: a weight of evidence evaluation of the epidemiology" — B.L. Finley, S.M. Benson, et al. (2018)
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• Three-dimensional evaluation of chemotherapy response in malignant pleural mesothelioma — G. Ak, M. Metintas, et al. (2010)

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