Sher, I agree with Laz and Vivian but will add a couple things:
1. About 20 to 25% of CK patients see significant shrinkage. So you shouldn't expect shrinkage, but it can occur.
2. Your tumor will have necrosis whether or not it shows up on the MRI. At the risk of putting words in other people's mouths, I think what Laz and Vivian meant to say is that "visible signs of necrosis (dark blotches showing in the MRI in the area of the tumor) are a bonus." The tumor will die (become necrotic) regardless of whether or not these dark blotches appear. The dark blotches show on MRIs taken with contrast (gadolinium injected) when blood flow is absent in tumor tissue (hence, it is necrotic or dead). The problem is that once the dead tissue forms scar tissue, it shows up white in the MRI and thus looks just like live tissue. So, if the MRI is taken before necrosis happens and the next MRI is taken after it's happened and scar tissue has already formed, you won't see the dark blotches (because the non-scarring necrosis phase happened in between MRIs).
So don't become attached to seeing necrosis. It's happening, regardless of whether your MRI shows it or not. Your AN is on its way outta here, so long farewell good riddance. Done deal.
Peace,
TW
P.S. FYI, dark blotches can also appear in the tumor area on an MRI if the image was taken before the contrast agent had a chance to fully absorb into/permeate the tumor. So, dark blotches are nice to see but may not always indicate necrosis. It's helpful when the technician injecting you takes an extra minute or so to let the contrast agent fully absorb before starting the imaging process.