Intrathoracic chemo-thermotherapy with radiofrequency waves after extrapleural pneumonectomy for malignant pleural mesothelioma

Although multimodal treatment is advocated for malignant pleural mesothelioma (MPM), a standard therapeutic regimen has not been established. This study evaluated the outcome of our aggressive treatment including extrapleural pneumonectomy (EPP) and postoperative intrathoracic chemo-thermotherapy (PICT). Moreover, we assessed the association between the clinical effect and an in vitro chemosensitivity test. Eleven patients with MPM underwent treatment including EPP followed by PICT using 8 MHz radiofrequency waves. In vitro chemosensitivity was examined using the collagen gel droplet embedded culture drug-sensitivity test (CD-DST). Complete resection was performed in nine patients. More than two courses of PICT with sufficient heating were completely performed in seven patients. There was no perioperative mortality. Grade 3 or 4 toxicity was not recognized. The median overall survival was 19 months, and the median local relapse-free survival was 17 months. Local recurrence was recognized in four patients (36.4%). Of these patients, three had received incomplete PICT. Four patients with complete PICT including a CD-DST-sensitive chemoagent did not develop local recurrence. Of three patients who received complete PICT including a CD-DST-resistant chemoagent, one tumor recurred locally. The present multimodal treatment including EPP and PICT is promising in local control for MPM. Furthermore, CD-DST may provide clinically useful information for MPM.