FDG PET/CT is useful for detecting infiltration to the port site in patients with malignant pleural mesothelioma

Our plain-English summary of FDG PET/CT is useful for detecting infiltration to the port site in patients with malignant pleural mesothelioma, by K. Kawaguchi, T. Taniguchi, N. Usami, et al (General Thoracic and Cardiovascular Surgery, 2014).

The study

• Authors: K. Kawaguchi, T. Taniguchi, N. Usami, T. Fukui, F. Ishiguro, S. Nakamura, K. Yokoi
• Journal: General Thoracic and Cardiovascular Surgery
• Published: 2014;62(3):157-62
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: One reason for the poor outcomes of multimodality therapies, including macroscopic complete resection, in patients with malignant pleural mesothelioma (MPM) is the difficulty of correctly staging the disease, which can result in incomplete resection. The purpose of this study was to investigate the aspects of tumor infiltration to the port site and the usefulness of preoperative FDG PET/CT for diagnosing MPM.

Methods: Between June 2007 and May 2013, 21 patients who underwent surgical treatment with curative intent for MPM that had been previously diagnosed on a video-assisted thoracic surgery (VATS) biopsy were included in this study.

Results: There were 17 males and four females, with a mean age of 63 years. The accumulation of FDG at the port site was observed in all nine patients with tumor infiltration to the port site, whereas this feature was not noted in 15 patients without tumor extension to the port site. There were more positive lymph node cases in the infiltration group than in the non-infiltration group (p = 0.02). No significant differences in survival were observed between the patients with and without tumor infiltration to the port site.

Conclusions: FDG PET/CT is useful for detecting tumor infiltration of MPM to the port site and may help to prevent local recurrence, especially port site relapse, following macroscopic complete resection. However, this condition is related to tumor aggressiveness; therefore, performing careful staging and determining the appropriate treatment strategy are required in such patients.

In plain English

This study looked back at 21 patients with malignant pleural mesothelioma treated at Nagoya University Hospital in Japan. All had surgery with curative intent between June 2007 and May 2013, after diagnosis by a video-assisted thoracic surgery (VATS) biopsy. It asked whether FDG PET/CT scans before surgery could show tumor spreading into the chest-wall 'port sites' left by earlier biopsy or drainage. The article does not report asbestos exposure. Tumor had spread to the port site in nine of the 21 patients (43 %). FDG uptake at the port site appeared in all nine and in none of the 12 patients without such spread. Lymph node metastasis was more common with port-site spread (6 of 9) than without (2 of 12; p = 0.020). Five of the nine had tumor at the surgical margin. Survival did not differ significantly between the groups (p = 0.934). Median follow-up was 9 months, and the authors named the short follow-up as a possible reason. The authors concluded that FDG PET/CT is useful for detecting port-site infiltration and that this condition is related to tumor aggressiveness.

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 surgical patients at a single institution, comparing preoperative FDG PET/CT findings with pathology of excised port sites
• Who was studied: 21 patients (17 males, 4 females; mean age 63, range 46 to 72) with malignant pleural mesothelioma diagnosed by VATS biopsy who underwent surgery with curative intent and macroscopic complete resection at Nagoya University Hospital, Japan, June 2007 to May 2013
• Exposure: The study examined preoperative imaging, not asbestos exposure: all patients had thin-slice contrast-enhanced CT and FDG PET/CT. Positive FDG accumulation was defined as SUVmax greater than 2.0. Asbestos or fiber exposure is not reported.
• Main results:
  • Tumor infiltration to the port site was found in 43 % of patients (nine of 21)
  • FDG accumulation at the port site was seen in all nine patients with port-site infiltration and in none of the 12 patients without it (p less than 0.001)
  • Counting individual port sites, 13 of 33 excised port sites were infiltrated with mesothelioma. 11 port sites showed FDG accumulation, with mean SUVmax 3.8 (range 2.0 to 6.9).
  • Lymph node metastasis was more frequent in the infiltration group (6 of 9 positive) than in the non-infiltration group (2 of 12 positive), p = 0.02
  • Five of the nine patients with port-site infiltration had positive surgical margins
  • Survival did not differ significantly between patients with and without port-site infiltration (p = 0.934). For all patients, median follow-up was 9 months, median survival 37 months, and two-year survival 54 %.
  • Port-site infiltration occurred in 3 of 4 females (75 %) and 6 of 17 males (35 %). This difference was not statistically significant (p = 0.149).
• The authors' conclusion: The authors concluded that FDG PET/CT is useful for detecting tumor infiltration of mesothelioma to the port site and may help prevent local recurrence after macroscopic complete resection. They also concluded that port-site infiltration is related to tumor aggressiveness, so careful staging and an appropriate treatment strategy, which sometimes includes non-surgical therapy, are required.
• Limitations the authors state:
  • The authors suggested that the short follow-up period, and the additional radiation given to port sites, may explain why they found no survival difference, unlike previous reports
  • The authors stated that PET/CT and CT have extremely low sensitivity and specificity for detecting mediastinal lymph node metastasis in mesothelioma (data not shown)

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, Staging, Thoracic Surgery, Video-Assisted Thoracoscopic Surgery (VATS), Biopsy.

Related studies

• 18F-FDG PET/CT in a recurrent diffuse malignant peritoneal mesothelioma — Q. Cao, M. Lu, et al. (2012)
• 18F-FDG PET/CT in suspected recurrences of epithelial malignant pleural mesothelioma in asbestos-fibers-exposed patients (comparison to standard diagnostic follow-up) — A. Niccoli-Asabella, A. Notaristefano, et al. (2013)
• 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)
• 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)
• 18F-FDG PET/CT in the management of patients with malignant pleural mesothelioma being considered for multimodality therapy: experience of a tertiary referral center — H.S. Elliott, U. Metser, et al. (2018)
• 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)

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