Consensus Guidelines for the Management of Peritoneal Surface Malignancies: Introduction and Methodology

Introduction The management of peritoneal surface malignancies (PSM) remains a challenge, characterized by limited high-level evidence and reliance on expert opinions. This paper outlines the methodology used in the development of clinical management pathways for PSM. Methods Building upon the Chicago Consensus Guidelines, a multidisciplinary North American panel was surveyed using a Modified Delphi technique to gauge the levels of agreement with clinical management pathways. Rapid systematic reviews were undertaken to address contentious questions specific to disease sites, which were structured using the Population, Intervention, Comparator, Outcome framework. Results Two consecutive rounds of voting were conducted between June 2023 and February 2024, addressing nine pathways spanning various conditions associated with PSM (colorectal, appendiceal, gastric, and neuroendocrine neoplasms, peritoneal mesothelioma, and gastrointestinal obstruction). The first Delphi consensus round involved 228 participants, of which 198 (87%) responded in the second round. Over 90% consensus was achieved in most blocks across all pathways. Eleven rapid systematic reviews were conducted, including 183 studies cumulatively out of 13,595 abstracts screened through PubMed. Perspectives from patient advocates and international experts were incorporated into these guidelines. The consortium’s multilevel approach also involved the creation of a peritoneal oncology curriculum, recommendations for billing and coding, and shared resources for perioperative care and patient information. Conclusion Experts indicated high levels of agreement with most pathway blocks across disease sites. These guidelines do not replace the need for high-level evidence but serve as guiding principles for critical decisions within the current landscape of PSM care. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.