Hemithoracic radiation therapy and brachytherapy after pleurectomy/decortication for malignant pleural mesothelioma: Results from a 30-year experience

Abstract

7180 Background: The role of pleurectomy/decortication (PD) and adjuvant radiotherapy (RT) in the treatment of malignant pleural mesothelioma (MPM) is controversial. We conducted a retrospective review to evaluate the efficacy and toxicity of this treatment. Methods: This study includes MPM patients treated with PD and adjuvant RT at the Memorial Sloan-Kettering Cancer Center from 1974 to 2003. PD consisted of resecting as much gross tumor as possible, typically removing the parietal, mediastinal, and visceral pleura. When indicated, patients received intra-operative brachytherapy to residual tumor. Results: Of the 123 patients in this study, 102 were male, 72 reported asbestos exposure, 86 had a positive smoking history, and 74 had epithelioid histology. All patients received external beam RT (median dose, 42.5 Gy; range, 7.2–67.8 Gy) to the ipsilateral hemithorax after surgery. Fifty four patients underwent brachytherapy with 125I or 192Ir implants to regions of residual disease. The median overall survival for all 123 patients was 13.5 months (range, 1–199 months) and the 2-year and 5-year overall survival were 23% and 5% respectively. Multivariate analysis for overall survival revealed non-epithelioid histology (p=0.002), radiation dose less than 40 Gy (p=0.001), left-sided disease (p=0.01) and the use of an implant (p=0.02) to be unfavorable. CTCAE Grade 3–5 toxicity was seen in 33 (27%) patients including pneumonitis (10%), pericarditis (8%), and esophagitis (4%). Conclusions: Pleurectomy/decortication with adjuvant radiotherapy is not an effective treatment option for patients with malignant pleural mesothelioma. Our results suggest that high external beam radiation therapy doses are needed to control microscopic disease and that residual disease cannot be eradicated, even with brachytherapy. The toxicity of the treatment is significant as suggested by the poor outcome in patients with left-sided disease, presumably from cardiac complications after radiation therapy. No significant financial relationships to disclose.