<qa>  What is the PET scan called?Evaluation of the function metabolism of the tumour will also be performed with a special scan called a Positron Emission Tomography PET scan. This PET scan will be performed before the first CMD-193 infusion, and after the 2nd and 4th infusions of CMD-193. Tumour assessment will take place before the study with appropriate tests such as CT scans, plain X-rays etc. These scans will be repeated 15-21 days after the 2nd, 4th and 6th infusions of CMD-193. 