Pleural effusion is a common complication of malignant disease and may pose a considerable management problem. Instillation should occur following drainage of an effusion to prevent or delay a recurrence caused by malignant cells, as after aspiration alone 60% of patients would present with pleural malignant recurrence (Wilkes [268]).

The most common neoplasms associated with the development of malignant pleural effusions are those of the (Wilkes [268]):

Such effusions can be very distressing to the patient, causing progressive discomfort, dyspnoea and death from respiratory insufficiency.

The alteration in normal anatomy due to the pressure of an effusion is illustrated in Figure 23.10. In health, less than 5 mL of transudate fluid is present between the visceral and parietal pleura. This fluid acts as a lubricant and hydraulic seal. Infections and malignancies disrupt this mechanism, often repeatedly. Patients may survive for months or years, therefore effective palliation is important in maintaining or improving their quality of life. Administering chemotherapy via this route may alleviate symptoms and also has the potential to deliver the drugs to a site of poor systemic penetration (Sewell et al. [230]). A study using intrapleural hypotonic cisplatin for malignant pleural effusion demonstrated encouraging results. Eighty patients were observed during the study, of whom 27 (34%) and 39 (49%) achieved a complete response and partial response respectively (Seto et al. [229]).