Intrapleural Administration of Hypotonic Cisplatin for Patients With Malignant Pleural Effusions and Non-Expandable Lungs.

BACKGROUND/OBJECTIVES: Thoracostomy and pleurodesis are the mainstay of management for malignant pleural effusions (MPEs). However, pleurodesis may not be effective for patients with MPEs and non-expandable lungs. Intrapleural chemotherapeutic agents such as hypotonic cisplatin are reportedly useful for treating MPEs with expandable lungs; however, their efficacy in patients with non-expandable lungs remains unclear. We aimed to analyze the efficacy and safety of intrapleural administration of hypotonic cisplatin in patients with MPEs and non-expandable lungs. METHODS: We retrospectively analyzed patients with MPEs of thoracic malignancies who were administered intrapleural hypotonic cisplatin. We investigated the changes in drained fluid volume, radiological outcomes at 4 weeks, thoracentesis-free survival, and adverse events. Between June 2009 and September 2022, 62 patients with MPEs received 69 administrations of hypotonic cisplatin. RESULTS: The most frequent primary site was the lungs (90.3%), and the mean drained fluid volume per day decreased by 65% (95% confidence interval [CI] 58%-72%) after intrapleural hypotonic cisplatin administration. At 4 weeks post-administration, MPE volumes decreased in 33 (53.2%) patients, remained unchanged in 22 (35.4%), and increased in seven (11.3%), based on frontal plane chest radiographs. The median thoracentesis-free survival was 456 days (95% CI, 122-842 days), the 30-day thoracentesis-free survival rate was 86.1%, and the 90-day survival rate was 70.8%. In total, 37 patients (59.7%) were censored. The most frequent adverse event was pleural empyema, observed in four patients. CONCLUSIONS: Intrapleural hypotonic cisplatin administration decreased or stabilized pleural effusion and may be useful for suppressing MPE with non-expandable lungs. CLINICALTRIALS: gov identifier: E23-0003.