The following images come from a patient with nasopharyngeal carcinoma.
WARNING, WARNING Will Robinson! to get the benefits from this follow the sequence!
Make the presumption that this is all the disease present, print off each image and mark with red pen the GTV.
Once this has been done on all three images, mark in orange pen the CTV.
Note that you have not been asked to draw the PTV (remember your name is not Dr Geometry, so you can't draw it!)
Listed below are links to my three attempts at GTV (axial, coronal, sagittal), and the following three at CTV (axial, coronal, sagittal). Don't peek until you have done your own. And don't laugh when you look at mine! Thanks!
So what is the test here? Well, the test is to draw what you think is there.