Communicating imaging findings in peritoneal mesothelioma: the impact of 'PAUSE' on surgical decision-making

Our plain-English summary of Communicating imaging findings in peritoneal mesothelioma: the impact of 'PAUSE' on surgical decision-making, by A. Chandramohan, N. Shah, A. Thrower, et al (Insights Into Imaging, 2021).

The study

• Authors: A. Chandramohan, N. Shah, A. Thrower, N.J. Carr, R. Mittal, F. Mohamed, B. Moran
• Journal: Insights Into Imaging
• Published: 2021;12(1):174
• Type of article: Review
• Cited by: 12 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

The peritoneal cavity is the second commonest site of mesothelioma after the pleural cavity. There are five histological types of peritoneal mesothelioma with variable symptomatology, clinical presentation and prognosis. Cystic mesothelioma is a borderline malignant neoplasm with a favourable prognosis, well-differentiated papillary mesothelioma is generally a low-grade malignancy, and all other varieties such as epithelioid, sarcomatoid and biphasic mesothelioma are highly malignant types of peritoneal mesothelioma with poor prognosis. Malignant peritoneal mesothelioma was considered inevitably fatal prior to the introduction of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in selected cases where long-term survival and cure could be achieved. However, the survival benefits following CRS and HIPEC mainly depend on completeness of cytoreduction, which come at the cost of high morbidity and potential mortality. Using the acronym 'PAUSE', we aimed at describing the key imaging findings that impact surgical decision-making in patients with peritoneal mesothelioma. PAUSE stands for peritoneal cancer index, ascites and abdominal wall disease, unfavourable sites of involvement, small bowel and mesenteric disease and extraperitoneal disease. Reporting components of 'PAUSE' is crucial for patient selection. Despite limitations of CT in accurately depicting the volume of disease, describing findings in terms of PAUSE plays an important role in excluding patients who might not benefit from CRS and HIPEC.

© 2021. The Author(s).

In plain English

This article was an educational review, not a new study of patients. The authors described how peritoneal mesothelioma (mesothelioma of the abdominal lining) appears on CT, MRI and PET-CT scans. They also described which scan findings affect decisions about cytoreductive surgery combined with heated chemotherapy inside the abdomen (HIPEC). They grouped these findings under the acronym 'PAUSE': peritoneal cancer index (a tumour-burden score), ascites and abdominal wall disease, unfavourable sites, small bowel and mesenteric disease, and extraperitoneal disease. They proposed a simple score for each part. They cited an earlier study of 59 patients, by some of the same authors, that found a higher scan-based index (34 vs. 17) in patients whose surgery did not achieve complete cytoreduction. They noted that CT can underestimate disease. The review did not study asbestos. Its introduction cited other research reporting an asbestos exposure history in around half of people with peritoneal mesothelioma, against 90% for pleural mesothelioma. The authors concluded that PAUSE features should be included in radiology reports. They stated that the link between PAUSE and outcomes is yet to be determined.

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: educational review describing imaging findings, illustrated with example patient images; no new patient data were collected
• Who was studied: No study population; the review discussed imaging of patients with peritoneal mesothelioma, using example cases
• Exposure: Asbestos exposure was not studied. As background from other research, the introduction stated that a history of asbestos exposure is found in around half of those with peritoneal mesothelioma, compared with 90% of those with pleural mesothelioma.
• Main results:
  • The review organised imaging findings under PAUSE: primary tumour and peritoneal carcinomatosis index (PCI), ascites and abdominal wall involvement, unfavourable sites, small bowel and mesenteric disease, and extraperitoneal metastases
  • The authors graded unfavourable sites as U0, U1 and U2; disease at U2 sites suggests complete cytoreduction is unlikely
  • Cited earlier radiological study of 59 patients: significantly higher radiological PCI (34 vs. 17) among patients with incomplete versus complete cytoreduction for malignant peritoneal mesothelioma
  • Cited other research: CT underestimates PCI, reported by some to be only half of that found at surgery
  • Cited UK-wide multidisciplinary team series of 155 patients with peritoneal mesothelioma reviewed 2016 to 2018: 22 (14.2%) underwent CRS and HIPEC, and 19 had complete cytoreduction
  • The authors proposed structured reporting with a score for each PAUSE component (Table 2)
• The authors' conclusion: The authors concluded that key imaging features organised by PAUSE should be included in radiology reports on patients with known or suspected peritoneal malignancy
• Limitations the authors state:
  • The correlation between PAUSE and patient outcome has not yet been determined

Topics

Medical terms in this study, explained in our Lexicon: Peritoneal Mesothelioma, Peritoneal Cavity, Mesothelioma, Pleural Cavity, Prognosis, Neoplasm, Well-Differentiated Papillary Mesothelioma, Epithelioid.

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