Malignant pleural mesothelioma: adjuvant therapy with radiation therapy

Abstract

It is a challenge to treat malignant pleural mesothelioma with radiation therapy (RT). For many years, conventional RT was delivered after extrapleural pneumonectomy (EPP) with acceptable results. However, the benefit of RT has never been definitively proven. Intensity modulated radiation therapy (IMRT) has been used, but some of the early experiences revealed fatal toxicity. As experience has increased, it now appears that RT, particularly with IMRT, is both feasible and effective.

Keywords: Mesothelioma; intensity modulated radiation therapy (IMRT); radiation pneumonitis; radiotherapy.

Figure 1

Pre-treatment CT scan (A) and PET scan (B) of a patient with malignant pleural mesothelioma. CT shows pleural thickening which demonstrated increased uptake on PET imaging.

Figure 2

The patient from Figure 1 after pleurectomy/decortication. Isodose distributions from an intensity modulated radiation therapy treatment plan in the axial (A) and coronal (B) planes, respectively. The planning target volume (PTV) is represented by the shaded red area. The 4,950, 4,650, 4,140 and 2,000 cGy isodose curves are represented by the yellow, green, magenta and orange curves respectively. The goal of the plan was to adequate dose to the periphery of the lung while limiting dose to the central portions.

Figure 3

The same patient six months after the completion of treatment. CT scan was obtained and representative slices from the axial plane (A) and coronal plane (B) are shown. The patient had no persistent symptoms from his radiation treatment. There is radiation change and pleural effusion in the left lung base, which is common after treatment.