Current readings: improvements in intensity-modulated radiation therapy for malignant pleural mesothelioma.

The treatment of malignant pleural mesothelioma with radiation therapy has always been a technical challenge. Early experience with intensity-modulated radiation therapy demonstrated troubling toxicity. Recent reports from institutions have demonstrated that with greater experience, intensity-modulated radiation therapy can be delivered safely, both in the setting of pneumonectomy or pleurectomy. After pneumonectomy, the dose to the contralateral lung must be minimized, preferably with a volume of lung receiving 20 Gy (V20) to less than 5% and a mean lung dose of approximately 10%. In the setting of 2 intact lungs, the mean lung dose can be as high as 20 Gy. Expected rates of grade 3 or worse radiation pneumonitis are 12%-20%. The rates of fatal pneumonitis are approximately 3%-8% in these studies, which demonstrate the considerable toxicity of treatment, even with improved technique.