Staging and response to therapy of malignant pleural mesothelioma

Earlier staging systems tended to concentrate on advanced malignant pleural mesothelioma (MPM) and considerable variation arose among the different systems. This was addressed in 1997 when the International Mesothelioma Interest Group (IMIG) staging system was approved. This is not a perfect system as many of the distinctions it makes cannot be identified by current computed tomography (CT) and magnetic resonance imaging (MRI) scanning. However presurgical staging using CT and MRI can be useful in delineating the extent and volume of disease and in detecting unexpected advanced disease as well as alerting clinicians to the possibility of early stage malignant pleural mesothelioma. Patients response to therapy can be measured using the response evaluation criteria in solid tumors (RECIST) criteria involving multiple measurements of a single diameter of tumour thickness.