A NOVEL TRIBLOCK COPOLYMER HYDROGEL TALC FOAM DELIVERY SYSTEM TO TREAT MALIGNANT PLEURAL EFFUSIONS

PURPOSE: Malignant pleural effusions (MPE) are a serious complication of cancer. Clinical failure of talc pleurodesis is thought to be due to poor dispersion. The foam delivery system was developed to improve dispersion by filling the entire thoracic cavity with talc. METHODS: To evaluate the foam system, C57BL/6 mice were injected with 1.5 x 10ˆ5 LL/2 cells into the right pleural space. The mice then receive either normal saline (NS), foam control (F), talc slurry (TS, 2mg/g) or talc foam (TF, 2mg/g) intrapleurally. Airspace volume was evaluated by CT after the injection of cells and again at the end of the experiment. Pleural fluid was measured and lungs/pleura were collected and % fibrosis of scanned tissue slides was determined. RESULTS: The talc foam group had a significantly better survival than the talc slurry group (21 vs 13.5 days, p< 0.0001). The average effusion volume was significantly less in the talc groups (140 vs 628 uL, p<0.001). Talc foam induced significant lung fibrosis (p <0.01), similar to the talc slurry group. On CT, TF significantly (p < 0.05) reduced loss of right lung volume (by 30-40%) compared to the loss of lung volume in the control group. This was not seen in the talc slurry group (p > 0.05). CONCLUSIONS: The hydrogel foam delivery system provides superior survival compared to the standard of care talc slurry. It is an effective sclerosing agent as demonstrated by the microscopic fibrosis, effect on reducing effusion volume, and preservation of lung volume. CLINICAL IMPLICATIONS: Hydrogel foam--a new approach to treat MPEs.