Response to Pembrolizumab in Metastatic Melanoma: Computed Tomography Texture Analysis as a Predictive Biomarker

The main purpose of this study is to find out if a type of CT (computed topography) scan can help to know if pembrolizumab is working. This CT scan (called Texture Analysis) looks at the tumour in fine detail. The use of this type of CT scan has not been studied in patients with metastatic melanoma. Investigators want to see if this CT scan will show if some patients being treated with pembrolizumab respond better than others. One of the other purposes is to compare the costs within this trial to costs of the standard of care.