Whole peritoneal radiotherapy in malignant ascites: a hypothesis-generating conceptual review.

Introduction: Malignant ascites (MA) impairs quality of life and remains difficult to control with symptomatic treatments. We summarize the rationale, uncertainties, and potential role of whole-peritoneal radiotherapy (WPRT) as an investigational palliative strategy for MA. The available evidence is limited, and no prospective or high-quality data currently establish WPRT as an effective treatment for MA. Content: We conducted a narrative review of MA in the context of palliative radiotherapy, whole-abdominal and whole-peritoneal irradiation, technical feasibility, and treatment-related toxicity. Because no prospective or systematically designed studies have evaluated WPRT using ascites-specific endpoints, indirect evidence was included. An illustrative radiotherapy planning simulation in a model patient was also presented to demonstrate technical considerations. Summary: Direct evidence supporting WPRT for symptom control in MA is lacking. However, the available literature provides a plausible rationale for this approach. Published literature supports the technical feasibility of large-field abdominal irradiation in selected oncological settings, but does not establish the feasibility, safety, or efficacy of WPRT specifically for MA. Outlook: WPRT should be regarded as an investigational palliative approach supported by clinical rationale rather than evidence-based practice. WPRT may extend symptom-directed palliative radiotherapy to selected patients with MA, but its value requires prospective evaluation using ascites-specific endpoints.