Malignant pleural mesothelioma (MPM) is a challenging cancer to treat for many reasons, one of which being the difficulty in assessing whether there has been any meaningful change in the volume of a cancer that doesn't tend to appear as a discrete mass, but most commonly as thickening of the pleura, the lining around the lung that is normally a thin, onion skin, but can thicken to be more like an orange rind or even thicker.  We can often see this pattern in some people with lung cancer who happen to have a form of the disease that also primarily appears as pleural-based deposits of cancer.

   Here's a post I did for another site about this issue of imaging to assess response in MPM.  I hope it's helpful to those of you with pleural-based disease.