In paper of Singh et al which was published in 2004 in Nature, they introduced “brain tumor initiating cells (BTIC)”. They showed that CD-133- positive cells as much as 100 cells can produce a brain tumor. You can find the full text by clicking HERE

A randomized study was published in Lancet in 2005 by Patchell et al. They showed that surgical decompression in spinal metastases is very effective. The group who underwent surgery plus radiotherapy showed better outcomes relative to patients who underwent radiotherapy alone. you can read the full text by clicking HERE.