NorthWest Biotherapeutics Inc (NWBO)

[Evaluate]

Although there was an improvement in progression-free survival, it could not be considered clinically relevant because of limitations in the methods available to measure the size of brain tumors.

I don't like the sounds of that at all. Does NWBO face a risk of the FDA taking the same position on their clinical trial end point?

Good question. I do not know the answer.
I started looking around a bit at recent articles about this topic. Below are a few links. Looks like some combination of imaging methods might give best results (as opposed to using a single imaging method).
www.ruralneuropractice.com/article.asp?issn=0976-3147;year=2014;volume=5;issue=1;spage=94;epage=98;aulast=Tiwari

www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0099616

www.ismrm.org/14/program_files/EP04.htm

www.appliedradiology.com/articles/the-basics-of-diffusion-and-perfusion-imaging-in-brain-tumors

www.biomedcentral.com/1471-2342/14/26