Radiological predictors of complete cytoreduction in 59 patients with peritoneal mesothelioma treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy at a UK referral centre

Our plain-English summary of Radiological predictors of complete cytoreduction in 59 patients with peritoneal mesothelioma treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy at a UK referral centre, by A. Chandramohan, A. Thrower, N. Shah, et al (The British Journal of Radiology, 2017).

The study

• Authors: A. Chandramohan, A. Thrower, N. Shah, F. Mohamed
• Journal: The British Journal of Radiology
• Published: 2017;90(1079):20170361
• Cited by: 9 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objective: To assess the imaging features of peritoneal mesothelioma and identify key anatomical sites that aid patient selection for complete cytoreduction.

Methods: Pre-operative imaging of 59 (32 males, 27 females) patients who underwent cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) for histologically proven peritoneal mesothelioma [36 malignant peritoneal mesothelioma, 23 cystic mesothelioma were reviewed. Imaging findings were correlated with surgical outcome. Best imaging predictors of complete cytoreduction, n = 22 and major tumour debulking, n = 12 were assessed.

Results: Most patients (88.9%) had diffuse peritoneal disease with mean radiological peritoneal cancer index of 18 ± 12 (range 2-39). Disease in the lesser omentum (n = 10), porta hepatis (n = 8), perigastric area (n = 5), mesentery (n = 25), small bowel (n = 17), hydronephrosis (n = 1), concurrent pleural disease (n = 2), lymph nodes (n = 1) and abdominal wall disease (n = 4) was considered unfavourable. While 78.9% of patients who underwent complete cytoreduction had no disease at unfavourable sites, 75% of those who underwent MTD did have disease at these sites. There was significant difference in the radiological peritoneal cancer index, severity of upper abdominal disease, small bowel and mesenteric involvement between patients who underwent complete cytoreduction and MTD for malignant peritoneal mesothelioma. Complete cytoreduction was not achieved in the presence of a rind of soft tissue around the small bowel (p = 0.016) and was unlikely in the presence of large volume upper abdominal disease (p = 0.06).

Conclusion: Involvement of key anatomical sites such as small bowel serosa and large volume upper abdominal disease reduced the likelihood of achieving complete cytoreduction in patients with malignant peritoneal mesothelioma. Advances in knowledge: Demonstration of small bowel disease and large volume upper abdominal disease on imaging in patients with malignant peritoneal mesothelioma can be used to identify patients who may not benefit from cytoreductive surgery.

In plain English

This retrospective UK study reviewed pre-operative scans, mostly CT, of 59 consecutive patients with peritoneal mesothelioma (36 malignant, 23 cystic) treated at a national referral centre between 1998 and 2015. Of these, 56 had cytoreductive surgery and three had only diagnostic laparoscopy and biopsy. The article gave no asbestos exposure histories for these patients, mentioning asbestos only as background from earlier studies. Of 34 operated patients with malignant disease, 22 had complete cytoreduction and 12 had major tumour debulking, which left visible tumour over 2.5 mm. The debulking group was older and had more disease overall, more upper-abdominal disease and more small bowel disease. In multivariate analysis, a rind of soft tissue around the small bowel was the strongest predictor of incomplete cytoreduction (p = 0.016). Large-volume upper-abdominal disease made debulking more likely (p = 0.06), which is above the study's 0.05 significance cut-off. Among 22 operated cystic mesothelioma patients, 21 had complete cytoreduction. The authors concluded that these two imaging findings reduced the likelihood of complete cytoreduction in malignant peritoneal mesothelioma. They also suggested that males with cystic mesothelioma may have larger lesions, and said these findings must be confirmed in a multicentre 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 study of pre-operative imaging compared with surgical outcome, at a single referral centre
• Who was studied: 59 consecutive patients (32 males, 27 females) with pathologically proven peritoneal mesothelioma, treated between 1998 and 2015 at a UK national referral centre. 36 had malignant peritoneal mesothelioma and 23 had cystic mesothelioma. 56 had cytoreductive surgery and 3 had only diagnostic laparoscopy and biopsy.
• Exposure: Asbestos exposure was not studied for these patients. The study examined pre-operative imaging findings, mostly CT, in relation to the outcome of surgery.
• Main results:
  • Of the 59 patients, 56 had cytoreductive surgery and 3 had diagnostic laparoscopy and biopsy. Of the 36 with malignant peritoneal mesothelioma, 34 had surgery.
  • Of 34 patients with malignant peritoneal mesothelioma who had surgery, 22 had complete cytoreduction and 12 had major tumour debulking (MTD).
  • Patients who had MTD were older: mean age 65.3, plus or minus 9.7 years, compared with 51 years for the complete cytoreduction group.
  • In the MTD group, the mean radiological peritoneal cancer index (24, plus or minus 12) and the surgical index (34, plus or minus 5) were significantly higher (p less than 0.05).
  • The mean sum of upper-abdominal disease scores was 5 in the MTD group and 2 in the complete cytoreduction group (p = 0.025).
  • Small bowel involvement was seen in 75% of the MTD group and 32% of the complete cytoreduction group (p = 0.019).
  • A rind of soft tissue around the small bowel was seen in 58.3% of the MTD group and 4% of the complete cytoreduction group (p = 0.001).
  • Perigastric disease was seen in 33.3% of the MTD group and 4.5% of the complete cytoreduction group (p = 0.042).
  • 75% of patients who had MTD had one or more unfavourable sites involved on imaging.
  • In multivariate analysis, a rind of soft tissue around the small bowel on CT was the strongest predictor of inability to achieve complete cytoreduction (B = -5.395, SE = 2.23, p = 0.016).
  • MTD was more likely with large-volume upper-abdominal disease (B = 0.795, SE = 0.433, p = 0.06). The study set significance at less than 0.05.
  • Of the cystic mesothelioma patients who had surgery, 21 had complete cytoreduction and one had MTD.
  • Among the 23 cystic mesothelioma patients, the radiological peritoneal cancer index was 20, plus or minus 9, in males and 11, plus or minus 10, in females (p = 0.047). Mesenteric involvement was more common in males (p = 0.026).
• The authors' conclusion: The authors concluded that, in malignant peritoneal mesothelioma, a rind of soft tissue around the small bowel and large-volume upper-abdominal disease on imaging reduced the likelihood of complete cytoreduction. They suggested that males with cystic mesothelioma may have larger lesions and more mesenteric involvement, and said these findings must be confirmed in a multicentre study.
• Limitations the authors state:
  • Image quality and imaging protocols varied, because most patients were referred from other institutions.
  • Surgical index data were incomplete because the study was retrospective, so surgical and radiological scores could not be compared.
  • The imaging findings describe only patients who had surgery at this centre and may not represent the full range of findings in the disease.
  • The authors noted that patients with small bowel obstruction or epigastric disease larger than 5 cm would not have been selected for surgery at their centre. They offered this as a possible reason for differences from an earlier study.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma, Peritoneal mesothelioma.

Medical terms in this study, explained in our Lexicon: Cytoreductive Surgery, Peritoneal Mesothelioma, HIPEC, Mesothelioma, Peritoneal Cancer Index (PCI), Omentum, Mesentery.

Related studies

• The Role of Ki-67 and Pre-cytoreduction Parameters in Selecting Diffuse Malignant Peritoneal Mesothelioma (DMPM) Patients for Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) — S. Kusamura, P.A. Torres Mesa, et al. (2016)
• Conversion to Complete Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Malignant Peritoneal Mesothelioma After Bidirectional Chemotherapy — F. Le Roy, M. Gelli, et al. (2017)
• Outcomes of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for peritoneal mesothelioma and predictors of survival — S.N.S. Gilani, A. Mehta, et al. (2018)
• Treating peritoneal mesothelioma with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. A case series and review of the literature — K. Stamou, D. Tsamis, et al. (2015)
• Adjuvant dendritic cell based immunotherapy (DCBI) after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal mesothelioma, a phase II single centre open-label clinical trial: rationale and design of the MESOPEC trial — N.L. de Boer, J.P. van Kooten, et al. (2019)
• Abdominal Wall Morbidity Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy — F. Struller, I. Koenigsrainer, et al. (2017)

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